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.

An algorithm, based on the matching of q-vectors pairs, is combined with three-dimensional pattern matching using a nearest-neighbors approach to index Laue and monochromatic serial crystallography data recorded on small unit cell samples.

A software package for Grazing Incident Wide Angle X-ray Scattering (GIWAXS) geared toward weakly ordered materials, including: scattering intensity normalization/uncertainty, scattering pattern indexing, and refractive shift correction.

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 proton-conducting material (NH4)4H2(SeO4)3 is examined to check whether its conductivity spectra are sensitive to subtle changes in the crystal structure and proton dynamics caused by external pressure. The AC conductivity was measured using impedance spectroscopy, in the frequency range from 100 Hz to 1 MHz, at temperatures 260 K < T < 400 K and pressures 0.1 MPa < p < 500 MPa. On the basis of the impedance spectra, carefully analyzed at different thermodynamic conditions, the p–T phase diagram of the crystal is constructed. It is found to be linear in the pressure range of the experiment, with the pressure coefficient value dTs/dp = −0.023 K MPa−1. The hydrostatic pressure effect on proton conductivity is also presented and discussed. Measurements of the electrical conductivity versus time were performed at a selected temperature T = 352.3 K and at pressures 0.1 MPa < p < 360 MPa. At fixed thermodynamic conditions (p = 302 MPa, T = 352.3 K), the sluggish solid–solid transformation from low conducting to superionic phase was induced. It is established that the kinetics of this transformation can be described by the Avrami model with an effective Avrami index value of about 4, which corresponds to the classical value associated with the homogeneous nucleation and three-dimensional growth of a new phase.

The proton-conducting crystal (NH4)4H2(SeO4)3 is examined to check whether its conductivity spectra and the phase transition to the superprotonic phase are sensitive to subtle changes in the crystal structure and proton dynamics caused by various thermodynamic conditions. It is established that the kinetics of this transformation can be described using the Avrami model with an effective Avrami index value associated with homogeneous nucleation and three-dimensional growth of a new phase.

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.

Crystal structure and microscopic optical properties of anthracene derivative compounds have been investigated by single-crystal synchrotron X-ray diffraction, laser confocal microscopy and fluorescence lifetime imaging microscopy.

This study presents the crystal structure of a thiol variant of the human mitochondrial branched-chain aminotransferase protein. Human branched-chain aminotransferase (hBCAT) catalyzes the transamination of the branched-chain amino acids leucine, valine and isoleucine and α-ketoglutarate to their respective α-keto acids and glutamate. hBCAT activity is regulated by a CXXC center located approximately 10 Å from the active site. This redox-active center facilitates recycling between the reduced and oxidized states, representing hBCAT in its active and inactive forms, respectively. Site-directed mutagenesis of the redox sensor (Cys315) results in a significant loss of activity, with no loss of activity reported on the mutation of the resolving cysteine (Cys318), which allows the reversible formation of a disulfide bond between Cys315 and Cys318. The crystal structure of the oxidized form of the C318A variant was used to better understand the contributions of the individual cysteines and their oxidation states. The structure reveals the modified CXXC center in a conformation similar to that in the oxidized wild type, supporting the notion that its regulatory mechanism depends on switching the Cys315 side chain between active and inactive conformations. Moreover, the structure reveals conformational differences in the N-terminal and inter-domain region that may correlate with the inactivated state of the CXXC center.

When songwriter Oscar Hammerstein penned the lyrics “fish gotta swim, birds gotta fly,” he clearly did not have the ratites in mind. Large flightless birds, the ratites include ostriches, emus, rheas and cassowaries, along with kiwis and several extinct species.

The post DNA evidence is rearranging the branches of the avian family tree appeared first on Smithsonian Insider.

A new Smithsonian study that examines 10 million years of the evolution of tiny coral-like organisms called cupuladriid bryzoans has revealed that some species of this organism lingered on earth for more than one million years after the event that ultimately caused their extinction: the rising of the Isthmus of Panama.

The post Fossils of tiny cupuladriid colonies reveal extinction can lag more than one million years after its cause appeared first on Smithsonian Insider.

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.

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.

The Smithsonian Center for Education and Museum Studies is hosting “Climate Change,” a three-day, free, education online conference Tuesday, Sept. 29 through Thursday, Oct. 1. This […]

The post Smithsonian to host online Climate Change conference Sept. 29-Oct. 1 appeared first on Smithsonian Insider.

Nearly 100 years ago, scientists detected the first signs of cosmic rays—subatomic particles (mostly protons) that zip through space at nearly the speed of light. […]

The post Telescope array finds new evidence that exploding stars are sources of cosmic rays appeared first on Smithsonian Insider.

Smithsonian astronomers have just discovered a rare example of a galaxy that appears to have a pair of giant black holes. Now they are trying to determine if those black holes are partners tied together by gravity, or if one of the two has been kicked out in a cosmic breakup.

The post Double Black-Hole Mystery: Dance Partners or Breakup Survivors? appeared first on Smithsonian Insider.

Finding this stellar relic wasn’t easy. It is 60,000 times dimmer than the faintest star visible to the unaided eye. The team also had to distinguish it from many surrounding stars that aren’t so old. Just like an archaeological dig, the hunt succeeded through a combination of patience and clever use of technology.

The post Ancient star discovered through patience and clever use of technology appeared first on Smithsonian Insider.

The stars move quickly because they are very close to each other, separated by only about one-fourth the distance from the Earth to the Moon. As a result, they share strong gravitational forces. They were once farther apart but have spiraled closer together over time. Billions of years from now, they will crash together and merge.

The post At 1,500,000 mph, twin stars in the constellation Cancer win speediest orbit award appeared first on Smithsonian Insider.

The research and patience has paid off. The sisters, Nababiep and Shera, have spent short periods of time with the male, Luke, individually and simultaneously. This happened only after they each had spent more than a year sniffing Luke through a mesh door (called a “howdy door”).

The post Patience and research may bring lion cubs to the National Zoo appeared first on Smithsonian Insider.

Eric Silver of SAO is pursuing innovative and interdisciplinary uses of his technique for chemical imaging at the cellular level.

The post Technology developed for X-ray astronomy is being adapted to study cancer cells appeared first on Smithsonian Insider.

The new study suggests that echolocation calls also serve a social function--bats listen to the ultrasonic calls of other bats to identify roost mates, bats of the same species, members of the opposite sex and intruders to their territory.

The post Scientists find ultrasonic calls of bats also serve a social function 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.

Take to the water with this behind-the-scenes video about Maryland blue crab research at the Smithsonian's Environmental Research Center. Fisheries Ecologist Eric Johnson takes viewers on a journey along the Rhode River to show how scientists tag and monitor Maryland blue crabs in the Chesapeake Bay watershed.

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Researchers at the Smithsonian Conservation Biology Institute conducted three different kinds of genetics tests and all yielded the same result—the Galapagos seabirds have been genetically different from the magnificent frigatebirds elsewhere for more than half a million years.

The post Genetic surprise: Magnificent frigatebird living on Galapagos Islands is distinct species 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.

A new study suggests that the annual long-distance migration of gray whales may be a relatively recent phenomenon, and that only a few thousand years ago, these marine mammals stayed much closer to home.

The post Ancient gray whales may have been homebodies appeared first on Smithsonian Insider.

For two weeks the team recorded and documented the community’s elders, families and llamas along a pilgrimage of remembrance in Pisaq, Peru.

The post American Indian Museum launches Chawaytiri documentation project in Peru 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.

A. sediba was discovered in 2008 in the Malapa Cave at the Cradle of Humankind World Heritage Site located outside Johannesburg.

The post Skeletal casts of early hominin ancestor from Africa donated to National Museum of Natural History appeared first on Smithsonian Insider.

A new species of Brazilian leaf beetle named Cachiporra extremaglobosa, (which translated means the “extremely globular billy club leaf beetle,”) was recently discovered by scientists at the Smithsonian’s National Museum of Natural History.

The post “Billy club” leaf beetle has been hiding in Smithsonian collections since 1959 appeared first on Smithsonian Insider.

On April 4 the Smithsonian and the Massachusetts Institute of Technology will launch VANISHED, an 8-week online/offline environmental disaster mystery game for middle-school children, meant […]

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Evidence for a diversified sea-based economy among North American inhabitants dating from 12,200 to 11,400 years ago is emerging from three sites on California's Channel Islands.

The post New archaeological evidence reveals California’s Channel Islands as North America’s earliest seafaring economy appeared first on Smithsonian Insider.

Funded by BP through the Florida Institute of Oceanography, the scientists will make the 10-day trip aboard the institute’s 115-foot research vessel. The divers, scientists and photographers will document hard bottoms of Florida, from the Keys to the Panhandle, to gain a better understanding of these sponge- and coral-dominated communities

The post Gulf of Mexico survey will benchmark diversity of ocean floor appeared first on Smithsonian Insider.

In recent research on Santa Rosa Island off the coast of Southern California, isotope readings of carbon and nitrogen found in the bones of Chumash Indians and domestic dogs excavated from archaeological sites show that both humans and dogs have nearly identical signatures of stable isotopes.

The post Ancient bond between humans and dogs revealed in isotopic signatures of their bones appeared first on Smithsonian Insider.

“Our results support the idea that environmental conditions on tropical non-breeding areas can influence the departure time for spring migration,” said Colin Studds, a postdoctoral fellow at the Smithsonian Conservation Biology Institute's Migratory Bird Center and lead author of the study.

The post Smithsonian scientists find declining rainfall is a major influence for migrating birds appeared first on Smithsonian Insider.

If intelligent and more advanced civilizations exist on other planets then its a good bet that some of these civilizations turned to asteroid mining long ago. If so, the hallmarks of their mining activities, such as unusual dirty halos of cast-off dust and debris around large asteroids, might be detectable from earth.

The post Evidence of asteroid mining in our galaxy may lead to the discovery of extraterrestrial civilizations appeared first on Smithsonian Insider.

A remarkable 5,000-year-old deposit of bones representing an entire herd of Persian gazelles recently discovered in northeastern Syria is firm evidence, scientists say, of an ancient hunting practice largely responsible for the near extinction of gazelles in this region today.

The post Archaeological evidence confirms mass hunting of gazelles 5,000 years ago appeared first on Smithsonian Insider.

In addition to the species name, Leafsnap provides high-resolution photographs and information about the tree's flowers, fruit, seeds and bark—giving the user a comprehensive understanding of the specie

The post Leafsnap, a new mobile app that identifies plants by leaf shape, is launched by Smithsonian and collaborators appeared first on Smithsonian Insider.

The most widely used methods for calculating species extinction rates are "fundamentally flawed" and overestimate extinction rates by as much as 160 percent, life scientists report May 19 in the journal Nature.

The post Methods for calculating species extinction rates overestimate extinction, says Smithsonian scientist appeared first on Smithsonian Insider.

Some--birds called wire-tailed manakins, residents of tropical forests in the Americas--are cooperators as well as competitors. They cooperate, forming alliances for a common cause.

The post Manakins, birds of tropical forests, form alliances for common good appeared first on Smithsonian Insider.

A scientist from the Smithsonian Tropical Research Institute uses a pick to dislodge the fossil skull of an extinct toothed whale from sediments on the […]

The post Fossil skull of an extinct toothed whale excavated from Panamanian sediments appeared first on Smithsonian Insider.

A new study shows that the desert tortoise, thought to be a single species for the last 150 years, is in fact two separate and distinct species, based on DNA evidence and biological and geographical distinctions.

The post New study reveals desert tortoise is actually two distinct species appeared first on Smithsonian Insider.

Small tissue samples collected from 238 wild turtles at 15 different locations across their range in Southern Mexico, Belize and Guatemala revealed a “surprising lack” of genetic structure, the scientists write in a recent paper in the journal Conservation Genetics.

The post Endangered river turtle’s genes reveal ancient influence of Maya Indians appeared first on Smithsonian Insider.

On Aug. 10, 1846, U.S. President James K. Polk signed the legislation that established the Smithsonian Institution as a trust administered by a Board of […]

The post Science at the Smithsonian: 165 years of scientific achievement appeared first on Smithsonian Insider.

The Zoo’s Smithsonian Conservation Biology Institute in Front Royal, Va., is celebrating the recent hatching of two Micronesian kingfisher (Todiramphus c. cinnamominus) chicks, a female and male, born July 25 and Aug. 20, respectively.

The post Zoo celebrates birth of two Micronesian kingfishers, a species extinct in the wild appeared first on Smithsonian Insider.

University of Florida and Smithsonian Tropical Research Institute scientists describe a new 20-foot extinct species of crocodile discovered in the same Colombian coal mine with Titanoboa, the world’s largest snake.

The post New 20-foot extinct species of crocodile discovered in Colombian coal mine appeared first on Smithsonian Insider.

Although cold and gaseous rather than a desert world, the newfound planet Kepler-16b is still the closest astronomers have come to discovering Luke Skywalker's home world of Tatooine.

The post From Star Wars to science fact: Tatooine-like planet discovered appeared first on Smithsonian Insider.