An X-ray cross-correlation study of the impact of ligand composition and salt content on the self-assembly of soft-shell nanoparticles is presented, indicating symmetry-selective formation of order.

An energy resolution of <10 µeV for the measurement of phonon energy change is achieved with the inelastic neutron spin echo technique on a conventional neutron triple-axis spectrometer.

The sin2ψ and cosα methods are compared via diffracting-grain identification from electron backscatter diffraction maps. Artificial textures created by the X-ray diffraction measurements are plotted and X-ray elastic constants of the diffracting-grain sets are computed.

This paper reports on the two-scale fractal structure of chromatin organization in the nucleus of the HeLa cell.

An attempt has been made to combine small-angle scattering of X-rays or neutrons with scanning electron microscopy in reciprocal space, in order to establish a structural analysis method covering a wide range of sizes from micro- to macro-scales.

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This article describes rational strategies for the optimization of crystal growth using precise in situ control of the temperature and chemical composition of the crystallization solution through dialysis, to generate crystals of the specific sizes required for different downstream structure determination approaches.

A new approach to variable-temperature measurements is presented, where the sample temperature changes continuously as a function of position.

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.

The sasPDF method, an extension of the atomic pair distribution function (PDF) analysis to the small-angle scattering (SAS) regime, is presented. The method is applied to characterize the structure of nanoparticle assemblies with different levels of structural order.

The diffraction response of a single crystal to electric field measured by X-ray diffraction by angles close to π. Such schemes allow one to determine with high (~ 10–5–10–6) accuracy the relative changes in the lattice constant.

The principles of using the Laue-analyzer as an X-ray optical element for separating two characteristic lines of an X-ray tube are presented.

The crystal structure of the organic pigment 2-monomethyl-quinacridone (Pigment Red 192, C21H14N2O2) was solved from X-ray powder diffraction data. The resulting average structure is described in space group Poverline 1, Z = 1 with the molecule on the inversion centre. The molecules are arranged in chains. The molecules, which have no inversion symmetry, show orientational head-to-tail disorder. In the average structure, the methyl group is disordered and found on both ends of the molecule with an occupancy of 0.5 each. The disorder and the local structure were investigated using various ordered structural models. All models were analysed by three approaches: Rietveld refinement, structure refinement to the pair distribution function (PDF) and lattice-energy minimization. All refinements converged well. The Rietveld refinement provided the average structure and gave no indication of a long-range ordering. The refinement to the PDF turned out to be very sensitive to small structural details, giving insight into the local structure. The lattice-energy minimizations revealed a significantly preferred local ordering of neighbouring molecules along the [0ar 11] direction. In conclusion, all methods indicate a statistical orientational disorder with a preferred parallel orientation of molecules in one direction. Additionally, electron diffraction revealed twinning and faint diffuse scattering.

The crystal structure of the mineral malayaite has been studied by single-crystal X-ray diffraction at a temperature of 20 K and by calculation of its phonon dispersion using density functional perturbation theory. The X-ray diffraction data show first-order satellite diffraction maxima at positions q = 0.2606 (8)b*, that are absent at room temperature. The computed phonon dispersion indicates unstable modes associated with dynamic displacements of the Ca atoms. The largest-frequency modulus of these phonon instabilities is located close to a wavevector of q = 0.3b*. These results indicate that the malayaite crystal structure is incommensurately modulated by static displacement of the Ca atoms at low temperatures, caused by the softening of an optic phonon with Bg symmetry.

The crystal structure of malayaite, CaSnOSiO4, at T = 20 K has been refined, based on the presence of satellite reflections with a modulation vector of 0.26b*. The structural modulation is attributed to a soft optic phonon, dominated by motion of the Ca atoms.

The crystal structure of the nanocrystalline pigment mono­methyl-quinacridone was solved from X-ray powder data. The orientational disorder was investigated using Rietveld refinements, structure refinement to the pair-distribution function, and lattice-energy minimizations of various ordered structural models.

The crystal structure of haemoglobin from Atlantic cod has been solved to 2.54 Å resolution. The structure consists of two tetramers in the crystallographic asymmetric unit. The structure of haemoglobin obtained from one individual cod suggests polymorphism in the tetrameric assembly.

Described here are instructions for building and using an inexpensive automated microscope (AMi) that has been specifically designed for viewing and imaging the contents of multi-well plates. The X, Y, Z translation stage is controlled through dedicated software (AMiGUI) that is being made freely available. Movements are controlled by an Arduino-based board running grbl, and the graphical user interface and image acquisition are controlled via a Raspberry Pi microcomputer running Python. Images can be written to the Raspberry Pi or to a remote disk. Plates with multiple sample wells at each row/column position are supported, and a script file for automated z-stack depth-of-field enhancement is written along with the images. The graphical user interface and real-time imaging also make it easy to manually inspect and capture images of individual samples.

Archaea are motile by the rotation of the archaellum. The archaellum switches between clockwise and counterclockwise rotation, and movement along a chemical gradient is possible by modulation of the switching frequency. This modulation involves the response regulator CheY and the archaellum adaptor protein CheF. In this study, two new crystal forms and protein structures of CheY are reported. In both crystal forms, CheY is arranged in a domain-swapped conformation. CheF, the protein bridging the chemotaxis signal transduction system and the motility apparatus, was recombinantly expressed, purified and subjected to X-ray data collection.

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°.

In southeastern Greenland, two rivers of ice named Helheim and Kangerdlugssuaq flow in spurts and starts toward the coast. They are much like any other […]

The post Astrophysical Observatory scientists are monitoring the mysterious movements of glaciers appeared first on Smithsonian Insider.

New observations by the Smithsonian’s Submillimeter Array, a radio telescope atop Mauna Kea in Hawaii, are shedding light on planet formation. The array provides sharp views by combining eight antennas into the equivalent of a single, large telescope. It can resolve details as small as a dime seen from seven miles away.

The post Cosmic “baby photos” of distant solar systems lend insight as to how planets form appeared first on Smithsonian Insider.

Determining the locations of future highways and roads in countries with tropical rainforests will be the greatest single factor in influencing future forest loss, fragmentation and degradation. In broad terms, roads can be thought of as the enemies of rainforests. By spreading people out across the forest, roads inherently promote rapid and widespread deforestation.

The post Roads kill rainforests. Stop them now, say Smithsonian biologists appeared first on Smithsonian Insider.

Native to Africa and Madagascar, females of the species have a body length of 1.5 inches and a leg span of 4 to 5 inches. Males are tiny in comparison.

The post Females are giants in newly discovered species of golden orb weaver spider appeared first on Smithsonian Insider.

Recently, researchers from Boston University and the Smithsonian Tropical Research Institute in Panama have been taking a closer look at the vibrations that red-eyed treefrog embryos use as cues to trigger early hatching. They discovered that treefrog embryos can evaluate different features of vibrations.

The post Researchers discover treefrog embryos can evaluate different features of vibrations appeared first on Smithsonian Insider.

White, who was a student at Columbian College from Accomack County, Va., died of pneumonia and complications from a mitral heart defect. When his coffin was unearthed, his identity was a deep mystery.

The post Remains of William Taylor White (1837-1852) donated to Smithsonian with his coffin and clothing appeared first on Smithsonian Insider.

The results show mergers of two dense stellar remnants are the likely cause of many of the supernovae that have been used to measure the accelerated expansion of the universe.

The post Mergers of dense stellar remnants are likely trigger for many supernovae appeared first on Smithsonian Insider.

The study found that infants whose mothers had higher levels of available milk energy soon after their birth, coped more effectively (moved around more, explored more, ate and drank) and showed greater confidence (were more playful, exploratory, curious and active) with this novel situation.

The post New study sees mother’s milk as a communications link that shapes infant temperament appeared first on Smithsonian Insider.

“Two things appear to be going on here,” explains Jacobus Boomsma, professor at the University of Copenhagen and Research Associate at STRI. “Right after mating there is competition between sperm from different males. Sperm is expendable. Later, sperm becomes very precious to the female who will continue to use it for many years to fertilize her own eggs, producing the millions of workers it takes to maintain her colony.”

The post Females shut down male-male sperm competition in leafcutter ants appeared first on Smithsonian Insider.

Kiwis come to National Zoo. The Smithsonian’s National Zoo will be using a new kiwi pair donated by the New Zealand Embassy to establish a breeding science center. […]

The post New Zealand Embassy donates kiwi pair to National Zoo Breeding Science Center appeared first on Smithsonian Insider.

The anemones—both of which are commonly called Tealia red anemones under the species of Urticina—spawned in late April and early May, just days apart. Henley collected the eggs and sperm from the more than 2,000-gallon tank and put them together in smaller tanks to increase the chances of fertilization. After fertilization, the larvae settled and metamorphosed into a polyp.

The post National Zoo scientists successfully grow two species of anemones in aquarium tanks appeared first on Smithsonian Insider.

The Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) PS1 telescope has discovered an asteroid about 150 feet in diameter that will come within 4 million miles of Earth in mid-October.

The post Rapid Response telescope system spots first potentially hazardous asteroid appeared first on Smithsonian Insider.

“Places of Invention,” a planned 3,500-square-foot exhibition at the National Museum of American History scheduled to open in 2014, will feature a selection of “hot spots” of invention and innovation—places where a critical mass of inventive people, networks, institutions, funding and other resources come together and creativity flourishes.

The post Lemelson Center receives $2.6 million grant for informal science education appeared first on Smithsonian Insider.

Today, researchers who found the first hypervelocity stars escaping the Milky Way announced that their search also turned up a dozen double-star systems. Half of those are merging and might explode as supernovae in the astronomically near future.

The post Astronomers discover merging star systems that might explode appeared first on Smithsonian Insider.

A new telescope has begun to virtually explore the solar system outback, and already is scoring discoveries.

The post New telescope exploring Solar System’s “outback” appeared first on Smithsonian Insider.

The new agreement, effective immediately through Dec. 5, 2015, stipulates that the Smithsonian's National Zoological Park will conduct research in the areas of giant panda breeding and cub behavior.

The post Smithsonian signs new giant panda agreement with China appeared first on Smithsonian Insider.

Subjects watched demonstrators for varying amounts of time. When given the pipe, each of the subjects in both groups opened the door on their first attempt using the method they had seen demonstrated.

The post Lemurs exhibit ability for social learning in zoo experiment appeared first on Smithsonian Insider.

A recent experiment by scientists at the Smithsonian Tropical Research Institute in Panama has revealed just how rising atmospheric carbon dioxide will deliver a one-two […]

The post Rising ocean temperatures and acidity may deliver deadly one-two punch to the world’s corals appeared first on Smithsonian Insider.

In a new paper, Harvard-Smithsonian Center for Astrophysics astronomer Hagai Perets studies the role of binary planetesimals--clumps that orbit each other and jointly mature via three basic processes.

The post New study examines how planetesimals influence the development of a planetary system appeared first on Smithsonian Insider.

Astronomers are piecing together the reasons for these huge energy outputs, while sorting out why our own galaxy is so modest. The two primary suspects are bursts of star formation that produce many hot young stars, and processes associated with accretion of material onto a supermassive black hole at a galaxy's nucleus.

The post Luminosity of extreme galaxy most likely driven by star formation appeared first on Smithsonian Insider.

Recent work has added dozens of new measurements to star-forming regions in the Milky Way. These measurements have changed the map of the Milky Way, indicating our galaxy has four spiral arms, not two, as previously thought.

The post Very Large Baseline Array telescope is helping Smithsonian astronomers remap Milky Way and Andromeda galaxies appeared first on Smithsonian Insider.

Over 170 molecules have been detected in space, from simple diatomic molecules like CO to complex organic molecules with over 70 atoms, such as fullerene. […]

The post Astronomers explore the rich chemistry surrounding an evolved star appeared first on Smithsonian Insider.

The National Zoological Park’s 23-year-old male red-ruffed lemur, Joven, enjoys a tasty St. Patrick’s Day frozen treat made of apples, pears, cucumbers, honeydew and diluted […]

The post A St. Partick’s Day treat for the Zoo’s red-ruffed lemur appeared first on Smithsonian Insider.

There is a new candidate for coldest known star: a brown dwarf with about the same temperature as a hot cup of coffee. That’s cool enough to begin crossing the blurry line between small cold stars and big hot planets.

The post New candidate for “coldest star” is same temperature as a hot cup of coffee appeared first on Smithsonian Insider.

Scientists at the Smithsonian’s National Zoo detected a secondary rise in urinary progesterone levels in the Zoo’s female giant panda Mei Xiang (may-SHONG). This hormone rise indicates that it should be 40 to 50 days before Mei Xiang either gives birth to a cub or comes to the end of a pseudopregnancy, or false pregnancy, which is common in giant pandas.

The post Hormone tests show Mei Xiang, the National Zoo’s female giant panda, may be pregnant appeared first on Smithsonian Insider.

Researchers at the Smithsonian Conservation Biology Institute and partnering organizations will build a frozen repository of Great Barrier Reef coral sperm and embryonic cells. Genetic banks composed of frozen biomaterials hold strong promise for basic and applied research and conservation of species and genetic variation.

The post Smithsonian Conservation Biology Institute to help create frozen repository of sperm and embryonic cells for Great Barrier Reef corals appeared first on Smithsonian Insider.

NASA's Kepler spacecraft is proving itself to be a prolific planet hunter. Within just the first four months of data, astronomers have found evidence for more than 1,200 planetary candidates. Of those, 408 reside in systems containing two or more planets, and most of those look very different than our solar system.

The post The Kepler spacecraft’s astounding haul of multiple-planet systems appeared first on Smithsonian Insider.

This new research, which involved both surface and aerial surveys, has revealed an enormous aggregation of whale sharks—the largest ever reported—with up to 420 individuals off the coast of the Yucatán Peninsula in Mexico.

The post Scientists discover the largest assembly of whale sharks ever recorded appeared first on Smithsonian Insider.

The National Zoo’s great cat program recently expanded with the arrival of two-and-a-half-year-old female Sumatran tiger, Damai, who is now out of quarantine and spending time outside in her exhibit where visitors can see her.

The post Damai, a two-and-a-half-year-old female Sumatran tiger, makes her debut at the National Zoo appeared first on Smithsonian Insider.

In 1987, light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost 400 years, allowing astronomers to study it in unprecedented detail as it evolves.

The post New supernova remnant lights up! appeared first on Smithsonian Insider.