The electron linear accelerators driving modern X-ray free-electron lasers can emit intense, tunable, quasi-monochromatic terahertz (THz) transients with peak electric fields of V Å−1 and peak magnetic fields in excess of 10 T when a purpose-built, compact, superconducting THz undulator is implemented. New research avenues such as X-ray movies of THz-driven mode-selective chemistry come into reach by making dual use of the ultra-short GeV electron bunches, possible by a rather minor extension of the infrastructure.

Anaerobic ammonium-oxidizing (anammox) bacteria play a key role in the global nitrogen cycle and in nitrogenous wastewater treatment. The anammox bacteria ultrastructure is unique and distinctly different from that of other prokaryotic cells. The morphological structure of an organism is related to its function; however, research on the ultrastructure of intact anammox bacteria is lacking. In this study, in situ three-dimensional nondestructive ultrastructure imaging of a whole anammox cell was performed using synchrotron soft X-ray tomography (SXT) and the total variation-based simultaneous algebraic reconstruction technique (TV-SART). Statistical and quantitative analyses of the intact anammox bacteria were performed. High soft X-ray absorption composition inside anammoxosome was detected and verified to be relevant to iron-binding protein. On this basis, the shape adaptation of the anammox bacteria response to iron was explored.

Quantum beats in fluorescence decay from Zeeman-split magnetic sublevels have been measured for helium Rydberg states excited by synchrotron radiation. The Zeeman quantum beats observed in this prototypical case were fitted with an equation from a theoretical formulation. It is proposed that Zeeman quantum beat measurement can be a useful way to simply evaluate the polarization characteristics of extreme ultraviolet light.

Phase-contrast enhanced micro-computed tomography reveals huge discontinuities at the interfaces between dental fillings and the tooth substrate. Despite the complex micromorphology, gaps in bonding could be visualized and quantified in 3D.

The open-source Python program PDB2INS is designed to prepare a .ins file for refinement with SHELXL [Sheldrick (2015). Acta Cryst. C71, 3–8], taking atom coordinates and other information from a Protein Data Bank (PDB)-format file. If PDB2INS is provided with a four-character PDB code, both the PDB file and the accompanying mmCIF-format reflection data file (if available) are accessed via the internet from the PDB public archive [Read et al. (2011). Structure, 19, 1395–1412] or optionally from the PDB_REDO server [Joosten, Long, Murshudov & Perrakis (2014). IUCrJ, 1, 213–220]. The SHELX-format .ins (refinement instructions and atomic coordinates) and .hkl (reflection data) files can then be generated without further user intervention, appropriate restraints etc. being added automatically. PDB2INS was tested on the 23 974 X-ray structures deposited in the PDB between 2008 and 2018 that included reflection data to 1.7 Å or better resolution in a recognizable format. After creating the two input files for SHELXL without user intervention, ten cycles of conjugate-gradient least-squares refinement were performed. For 96% of these structures PDB2INS and SHELXL completed successfully without error messages.

Errors in the article by Opara, Martiel, Arnold, Braun, Stahlberg, Makita, David & Padeste [J. Appl. Cryst. (2017), 50, 909–918] are corrected.

This paper reports an Fe-added Y2O3 crucible which is capable of balancing the solution spontaneously and is employed to effectively enhance the homogeneity of YBa2(Cu1−xFex)3O7−δ single crystals.

Because researchers do not understand the formation mechanism of cocrystals, the preparation of cocrystals is mostly done by trial and error. This study focuses on the cocrystal formation mechanism to improve the efficiency of cocrystal preparation.

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.

Book review

Immunoglobulin E (IgE) plays a central role in the allergic response, in which cross-linking of allergen by Fc∊RI-bound IgE triggers mast cell and basophil degranulation and the release of inflammatory mediators. The high-affinity interaction between IgE and Fc∊RI is a long-standing target for therapeutic intervention in allergic disease. Omalizumab is a clinically approved anti-IgE monoclonal antibody that binds to free IgE, also with high affinity, preventing its interaction with Fc∊RI. All attempts to crystallize the pre-formed complex between the omalizumab Fab and the Fc region of IgE (IgE-Fc), to understand the structural basis for its mechanism of action, surprisingly failed. Instead, the Fab alone selectively crystallized in different crystal forms, but their structures revealed intermolecular Fab/Fab interactions that were clearly strong enough to disrupt the Fab/IgE-Fc complexes. Some of these interactions were common to other Fab crystal structures. Mutations were therefore designed to disrupt two recurring packing interactions observed in the omalizumab Fab crystal structures without interfering with the ability of the omalizumab Fab to recognize IgE-Fc; this led to the successful crystallization and subsequent structure determination of the Fab/IgE-Fc complex. The mutagenesis strategy adopted to achieve this result is applicable to other intractable Fab/antigen complexes or systems in which Fabs are used as crystallization chaperones.

Scientists at the Smithsonian Institution examined the feather remains from the Jan. 15, 2009, US Airways Flight 1549 bird strike to determine not only the species, but also that the Canada geese involved were from a migratory, rather than resident, population. This knowledge is essential for wildlife professionals to develop policies and techniques that will reduce the risk of future collisions. The team’s findings were published in the journal “Frontiers in Ecology and the Environment” in June.

The post Scientists Determine Geese Involved in Hudson River Plane Crash Were Migratory appeared first on Smithsonian Insider.

The fossil teeth of a 15- to 18-million-year-old three-toed browsing horse, Anchitherium clarencei, were recently discovered by scientists from the Smithsonian Tropical Research Institute and the […]

The post Fossil teeth of 15-million-year-old browsing horse found in Panama Canal excavations. appeared first on Smithsonian Insider.

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 recent survey of the bottom-dwelling animals of the Chesapeake has revealed that communities of even these relatively hardy organisms are under stress. Many regions of the bay are becoming inhospitable to bottom-dwelling animals because of a lack of oxygen—a condition known as “hypoxia.”

The post Bottom-dwelling creatures in the Chesapeake Bay need more oxygen, study finds. appeared first on Smithsonian Insider.

The spread of Africanized honey bees across Central America has had a much smaller impact on native tropical bee species than scientists previously predicted...

The post Native bees prove resilient in competition with invasive African honey bees 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.

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.

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.

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 Stephen L. Wood collection brings the collection of bark beetles held in the Natural History Museum’s Department of Entomology to an impressive 180,000 specimens, making it one of the most extensive collections in world.

The post Eighty-thousand bark beetles enter National Museum of Natural History collections appeared first on Smithsonian Insider.

Recently, scientists at the Smithsonian Tropical Research Institute in Panama discovered that the brain region responsible for learning and memory is larger in the social queens than in the solitary queens of this species. Their study is the first comparison of the brain sizes of social and non-social individuals of the same species.

The post For sweat bees, being social builds a more developed brain appeared first on Smithsonian Insider.

"Just like mirrors in a changing room show you a clothing outfit from all sides, interstellar dust clouds act like mirrors to show us different sides of the supernova," Rest explains.

The post Astronomers see supernova from a new angle appeared first on Smithsonian Insider.

More than 25 years ago, researchers at the Smithsonian Environmental Research Center's Fish and Invertebrate Ecology Lab began taking weekley surveys of the species that make their way in and out of Muddy Creek.

The post Net survey: For quarter century, scientists have been counting creatures traveling Chesapeake Bay tributary 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.

A roundup of recent articles featuring spiders, bats and rats....

The post A Halloween roundup featuring recent articles on spiders, bats and rats 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.

The most puzzling characteristic of deep-sea dragonfishes (stromiids) is found where their backbone (or vertebral column) approaches the back of their skull. In the anterior region of the backbone, these […]

The post Deep-sea dragonfish research appeared first on Smithsonian Insider.

NASA's Fermi Gamma-ray Space Telescope has unveiled a previously unseen structure centered in the Milky Way--a finding likened in terms of scale to the discovery of a new continent on Earth. The feature, which spans 50,000 light-years, may be the remnant of an eruption from a supersized black hole at the center of our galaxy.

The post Astronomers find giant, previously unseen structure in our galaxy appeared first on Smithsonian Insider.

Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the Panama Amphibian Rescue and Conservation Project is the first to successfully breed this species.

The post National Zoo and partners first to breed critically endangered tree frog appeared first on Smithsonian Insider.

"Physics for the 21st Century," a free, on-line course developed at the Harvard-Smithsonian Center for Astrophysics about current research in physics is now available.

The post Free, online course in physics offered by the Harvard-Smithsonian Center for Astrophysics 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.

To honor Harvard-Smithsonian astronomer John Huchra, who passed away in October 2010, his friends and colleagues at the Harvard-Smithsonian Center for Astrophysics have created a […]

The post New interactive World Wide Telescope tour chronicles career of Harvard-Smithsonian astronomer John Huchra 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.


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.

For more than three decades JoGayle Howard dedicated her life and work to reproducing endangered species.

The post JoGayle Howard, National Zoological Park pioneer in reproductive biology, dies 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.

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.

To help regulators and engineers develop and test such treatment systems, and ultimately enforce these standards, a team of researchers developed a statistical model to see how to count small, scarce organisms in large volumes of water accurately.

The post Smithsonian researchers help block ship-borne bioinvaders with new screening strategy appeared first on Smithsonian Insider.

According to new research by Nick Stone and Avi Loeb (Harvard-Smithsonian Center for Astrophysics), upcoming sky surveys might offer astronomers a way to catch a gorging black hole "in the act."

The post Astronomers seek monster black hole gorging on a buffet of stars appeared first on Smithsonian Insider.

A team of scientists led by the Smithsonian Institution has discovered a fossilized dinosaur skull and neck vertebrae that not only reveal a new species, but also an evolutionary link between two groups of dinosaurs.

The post Scientists discover new species of dinosaur bridging a gap in the dinosaur family tree 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.

The National Zoo has received a breeding pair of Asian small-clawed otters at Asia Trail for the first time. Mac, a three-year-old male from the Point Defiance Zoo in Tacoma, Wash., and Smidge, a five-year-old female from the Columbus Zoo in Ohio, arrived in April and are now in their exhibit.

The post Keepers are optimistic about Zoo’s new breeding pair of Asian small-clawed otters appeared first on Smithsonian Insider.

Five cheetah cubs were born May 28 to 6-year-old Amani at the Smithsonian Conservation Biology Institute in Front Royal, Va. Amani is a dedicated mother according to keepers, who have observed her nursing and grooming the cubs.

The post Five cheetah cubs born at Smithsonian Conservation Biology Institute appeared first on Smithsonian Insider.