More than 70 scientists from 9 institutions including the Smithsonian Tropical Research Institute, sequenced the entire genome of the butterfly genus Heliconius, a brightly colored favorite of collectors and scientists since the Victorian era.

The post Heliconius butterfly genome explains wing pattern diversity appeared first on Smithsonian Insider.

This past summer, Laura Walker became the first scientist to collect slime molds from soils at the Barro Colorado Nature Monument in Panama, a reserve administered by the Smithsonain since 1946.

The post Panama’s slime molds get attention from Arkansas University grad student appeared first on Smithsonian Insider.

Matthew C. Larsen, associate director for climate and land-use change at the U.S. Geological Survey, has been appointed the Director of the Smithsonian Tropical Research […]

The post Matthew Larsen appeared first on Smithsonian Insider.

A new study of gamma-ray light from the center of our galaxy makes the strongest case to date that some of this emission may arise […]

The post Fermi data offer clues to dark matter appeared first on Smithsonian Insider.

More than two million migrating raptors passed over Panama City on Sunday, Nov. 2, doubling the previous record of almost 900,000 tallied in a single […]

The post Panama shatters raptor migration record appeared first on Smithsonian Insider.

Every massive galaxy has a black hole at its center, and the heftier the galaxy, the bigger its black hole. But why are the two […]

The post Dark matter guides growth of supermassive black holes appeared first on Smithsonian Insider.

Batteries power virtually every aspect of modern life. So small, so portable, and so easy to forget—but how many times have you simply started your […]

The post Unplugged: 5 batteries that gave the world a jolt appeared first on Smithsonian Insider.

The odds of being attacked and castrated by a variety of parasitic flatworms increases for marine horn snails the farther they are found from the […]

The post Parasitic flatworms flout global biodiversity patterns appeared first on Smithsonian Insider.

From patterns etched into the skin of an ancient mummy to the colorful designs that adorn people today, tattoos are not just skin deep; they […]

The post Tattoos: Telling Stories in the Flesh. Q&A with Lars Krutak appeared first on Smithsonian Insider.

Tattoos really are more than skin deep—and that raises questions about their safety. Many people enjoy the aesthetic beauty of tattoos. But the brightly colored […]

The post Is Tattoo Ink Safe? appeared first on Smithsonian Insider.

The debate about the world’s oldest tattoos is over—they belong to Ötzi, the European Tyrolean Iceman who died and was buried beneath an Alpine glacier […]

The post Ancient Ink: Iceman Otzi Has World’s Oldest Tattoos appeared first on Smithsonian Insider.

As the Zika virus is rapidly taking hold around the world, health officials are racing to find its cause and prevent further spread of the […]

The post Smithsonian’s mosquito collection is weapon in battle against Zika appeared first on Smithsonian Insider.

Keith Gagnon, a 9-year-old fascinated by birds, talks about the importance of bird conservation and why birds really matter. Step outside your house in the […]

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President Jimmy Carter, an avid birder, talks about the importance of bird conservation and why birds really matter. Step outside your house in the morning […]

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According to a new survey of residents living near two major national parks in Panama, jaguars deserve increased protection. Nature and wildlife are considered national […]

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Marine mammologist Matthew Leslie aims his crossbow from the bow of a moving boat at the dolphins riding the breaking waves below. A dolphin will […]

The post Some dolphins cross the Pacific more easily than others. Why that matters for protecting them appeared first on Smithsonian Insider.

In the battle against invasive species, giant commercial ships are on the front lines. But even when they follow the rules, one of their best […]

The post Battle against invasive marine species comes up short as global shipping surges appeared first on Smithsonian Insider.

Serial crystallography records still diffraction patterns from single, randomly oriented crystals, then merges data from hundreds or thousands of them to form a complete data set. To process the data, the diffraction patterns must first be indexed, equivalent to determining the orientation of each crystal. A novel automatic indexing algorithm is presented, which in tests usually gives significantly higher indexing rates than alternative programs currently available for this task. The algorithm does not require prior knowledge of the lattice parameters but can make use of that information if provided, and also allows indexing of diffraction patterns generated by several crystals in the beam. Cases with a small number of Bragg spots per pattern appear to particularly benefit from the new approach. The algorithm has been implemented and optimized for fast execution, making it suitable for real-time feedback during serial crystallography experiments. It is implemented in an open-source C++ library and distributed under the LGPLv3 licence. An interface to it has been added to the CrystFEL software suite.

Relativistic electron diffraction depends on linear and quadratic terms in the electric potential, the latter being neglected in the frequently used relativistically corrected Schrödinger equation. The quadratic electric potential term modifies atomic scattering amplitudes in particular for large-angle scattering and backscattering. The respective correction increases with increasing scattering angle, increasing atomic number and increasing kinetic energy. Conventional tabulations for electron scattering and its large-angle extrapolations can be amended in closed form by a universal correction based on the screened Coulomb potential squared.

in Outlook Express and Thunderbird

Dr. Thomas R. Watters of the Center for Earth and Planetary Studies at the Smithsonian's National Air and Space Museum talks about his research in astronomy, particularly our moon. More about space science at http://www.nasm.si.edu

The post Meet Our Scientist: Tom Watters – Moon Science appeared first on Smithsonian Insider.

Meet the Smithsonian's Matthew Carrano, curator of Dinosauria at the Smithsonian's National Museum of Natural History in Washington, D.C. Matthew studies all things dinosaur, but focuses on the evolutionary history of predatory (meat eating) dinosaurs.

The post Meet Our Scientist: Matthew Carrano, curator of dinosauria at the Smithsonian’s National Museum of Natural History appeared first on Smithsonian Insider.

The post How do paleontologists identify dinosaur teeth? Smithsonian Curator Matthew Carrano identifies Cretaceous dinosaur teeth from the Washington D.C. area. appeared first on Smithsonian Insider.

The post How do we know if dinosaurs cared for their young? Smithsonian curator Matthew Carrano reveals the fossil evidence. appeared first on Smithsonian Insider.

The post Smithsonian planetary scientist Tom Watters explains how he knows the moon is shrinking appeared first on Smithsonian Insider.

The post What will invasive round goby fish do to Great Lakes streams? Join SERC post doc Matt Kornis and find out. appeared first on Smithsonian Insider.

U.S. Secretary of the Interior Sally Jewell talks about the importance of bird conservation and why birds really matter. Step outside your house in the […]

The post Why Birds Really Matter: Sally Jewell appeared first on Smithsonian Insider.

Catherine McKenna, Canada’s Minister of the Environment and Climate Change, talks about the importance of bird conservation and why birds really matter. Step outside your […]

The post Why Birds Really Matter: Catherine McKenna appeared first on Smithsonian Insider.

What they observed was unique among all bird species: successful male caribs maintained and defended territories with nectar supplies that were two to five times greater than their daily needs and also isolated part of their crop for the exclusive feeding rights of visiting females.

The post A well-defended territory is what some female hummingbirds find most attractive in a mate appeared first on Smithsonian Insider.

Scientific inspiration springs from many sources. In the case of Smithsonian botanist David Kenfack, ant bites were the inspiration for a recent paper he co-authored […]

The post Sweet life: tropical plants attract ants with sugary nectar appeared first on Smithsonian Insider.

This work presents a technique for extracting the detailed shape of peaks with extended, overlapping tails in an X-ray powder diffraction pattern. The application discussed here concerns crystallite size broadening, though the technique can be applied to spectra of any origin and without regard to how the profiles are to be subsequently analyzed. Historically, the extraction of profile shapes has been difficult due to the complexity of determining the background under the peak, resulting in an offset of the low-frequency components of the Fourier transform of the peak known as the `hook' problem. The use of a carefully considered statistical weighting function in a non-linear least-squares fit, followed by summing the residuals from such a fit with the fit itself, allows one to extract the full shape of an isolated peak, without contributions from either the background or adjacent peaks. The extracted shape, consisting of the fit function recombined with the residuals, is not dependent on any specific shape model. The application of this to analysis of microstructure is performed independently of global parametric models, which would reduce the number of refined parameters; therefore the technique requires high-quality data to produce results of interest. The effectiveness of the technique is demonstrated by extraction of Fourier transforms of peaks from two sets of size-broadened materials with two differing pieces of equipment.

The unit-cell reduction described by Selling and used by Delone (whose early publications were under the spelling Delaunay) is explained in a simple form. The transformations needed to implement the reduction are listed. The simplicity of this reduction contrasts with the complexity of Niggli reduction.

Compared with X-rays, electron diffraction faces a crucial challenge: dynamical electron scattering compromises structure solution and its effects can only be modelled in specific cases. Dynamical scattering can be reduced experimentally by decreasing crystal size but not without a penalty, as it also reduces the overall diffracted intensity. In this article it is shown that nanometre-sized crystals from organic pharmaceuticals allow positional refinement of the hydrogen atoms, even whilst ignoring the effects of dynamical scattering during refinement. To boost the very weak diffraction data, a highly sensitive hybrid pixel detector was employed. A general likelihood-based computational approach was also introduced for further reducing the adverse effects of dynamic scattering, which significantly improved model accuracy, even for protein crystal data at substantially lower resolution.

A new aspherical scattering factor formalism has been implemented in the crystallographic least-squares refinement program SHELXL. The formalism relies on Gaussian functions and can optionally complement the independent atom model to take into account the deformation of electron-density distribution due to chemical bonding and lone pairs. Asphericity contributions were derived from the electron density obtained from quantum-chemical density functional theory computations of suitable model compounds that contain particular chemical environments, as defined by the invariom formalism. Thanks to a new algorithm, invariom assignment for refinement in SHELXL is automated. A suitable parameterization for each chemical environment within the new model was achieved by metaheuristics. Figures of merit, precision and accuracy of crystallographic least-squares refinements improve significantly upon using the new model.

Diffuse scattering is a rich source of information about disorder in crystalline materials, which can be modelled using atomistic techniques such as Monte Carlo and molecular dynamics simulations. Modern X-ray and neutron scattering instruments can rapidly measure large volumes of diffuse-scattering data. Unfortunately, current algorithms for atomistic diffuse-scattering calculations are too slow to model large data sets completely, because the fast Fourier transform (FFT) algorithm has long been considered unsuitable for such calculations [Butler & Welberry (1992). J. Appl. Cryst. 25, 391–399]. Here, a new approach is presented for ultrafast calculation of atomistic diffuse-scattering patterns. It is shown that the FFT can actually be used to perform such calculations rapidly, and that a fast method based on sampling theory can be used to reduce high-frequency noise in the calculations. These algorithms are benchmarked using realistic examples of compositional, magnetic and displacive disorder. They accelerate the calculations by a factor of at least 102, making refinement of atomistic models to large diffuse-scattering volumes practical.

The enanti­opure monopyrrolidine derivative (2S)-methyl (Z)-5-(2-tert-but­oxy-1-cyano-2-oxo­ethyl­idene)pyrrolidine-2-carboxyl­ate, C13H18N2O4, (1), represents a potential ligand and an attractive inter­mediate for the synthesis of chiral metal com­plexes. At the mol­ecular level, the com­pound features an intra­molecular N—H⋯O hydrogen bond; neighbouring mol­ecules inter­act via N—H⋯N contacts to form chains along [100]. Due to its elemental com­position, resonant scattering of the target com­pound is entirely insignificant for diffraction experiments with Mo Kα and small even for Cu Kα radiation. A preliminary study with the harder radiation type confirmed the chiral space group and the suitability of the single crystal chosen; as expected, the results concerning the absolute structure remained com­pletely inconclusive. A second data collection with the longer wavelength gave satisfactory quality indicators for the correct handedness of the mol­ecule, albeit with high standard uncertainties. The absolute configuration has been assessed independently: CD spectra for both enanti­omers of the target mol­ecule were calculated and the spectrum for the S-configured stereoisomer was in agreement with the experiment. The Cotton effect of (1) may be ascribed to π–π* transitions from HOMO to LUMO and from HOMO to LUMO+1. As both independent techniques agree with respect to the handedness of the target mol­ecule, the absolute structure may be assigned with a high degree of confidence.

The Debye scattering equation (DSE) is generalized and augmented in order to account for moderate texture effects, yielding the differential cross section as a function of atomic coordinates and texture coefficients subject to symmetry constraints. Implications for the evaluation of the pair distribution function (PDF) as a direct transform of powder diffraction data from textured samples are also discussed.

(The Paypers) Chubb’s SME Cyber Preparedness Report has revealed that 84% of small and medium...

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A National Science Foundation-funded research has discovered the root cause of why lithium metal batteries fail -- bits of lithium metal deposits break off from the surface of the anode during discharging and are trapped as "dead" or inactive lithium that the battery can no longer access. The discovery challenges the conventional belief that lithium metal batteries fail because of the growth of a layer, called the solid electrolyte interphase (SEI), between the lithium anode and the electrolyte. The researchers made their discovery by developing a technique to measure the amounts of inactive lithium species on the anode -- a first in the field of battery research -- and studying their micro- and nanostructures. The findings could pave the way for bringing rechargeable lithium metal batteries from the lab to the market.

Image credit: University of California - San Diego

Focused attention by world leaders is needed to address the substantial challenges posed by disposal of spent nuclear fuel from reactors and high-level radioactive waste from processing such fuel for military or energy purposes.

Representatives from academies and research organizations around the world sent messages of condolence and support to members, officials and staff of the U.S. National Academies in the wake of terrorist attacks on the World Trade Center and the Pentagon. The following are excerpts from some of these messages.

Every year, approximately 100 million* adult Americans experience chronic pain, a condition that costs the nation between $560 billion and $635 billion annually, says a new report from the Institute of Medicine.

The U.S. electric power delivery system is vulnerable to terrorist attacks that could cause much more damage to the system than natural disasters such as Hurricane Sandy, blacking out large regions of the country for weeks or months and costing many billions of dollars, says a newly released report by the National Research Council.

It is now possible to estimate the influence of climate change on some types of extreme events, such as heat waves, drought, and heavy precipitation, says a new report from the National Academies of Sciences, Engineering, and Medicine.

The U.S. Department of Health and Human Services (HHS) should lead efforts among federal partners and stakeholders to design, implement, and evaluate a multipronged, evidence-based national strategy to reduce stigma toward people with mental and substance use disorders, says a new report from the National Academies of Sciences, Engineering, and Medicine.

U.S. adults perform comparably to adults in other economically developed countries on most measures of science knowledge and support science in general, says a new report from the National Academies of Sciences, Engineering, and Medicine.