Bird species in rainforest fragments in Brazil that were isolated by deforestation first disappeared and then reappeared during the next quarter-century.

The post “Extinct” birds reappear in rainforest fragments in Brazil appeared first on Smithsonian Insider.

Non-native plant species pose a significant threat to the natural ecosystems of the United States. Many of these invasive plants are escapees from gardens and […]

The post Escape of the invasives: Top six invasive plant species in the United States appeared first on Smithsonian Insider.

Plants are among the world’s best carbon sinks, but there’s a side to the plant-CO2 love affair that’s rarely discussed. When carbon dioxide rises, plants […]

The post The strange, controversial way plants trap CO2 appeared first on Smithsonian Insider.

Tropical forests are a sometimes underappreciated asset in the battle against climate change. They cover 7 percent of land surface yet hold more than 30 […]

The post Vine-choked forests can’t capture carbon appeared first on Smithsonian Insider.

When Gary Graves cranks up his boom box and drives remote back roads through pine plantations in Texas, Louisiana and other southern states, a few […]

The post Rare American warbler surprises scientists by adapting, thriving in a new ecosystem appeared first on Smithsonian Insider.

Residents of the southeastern United States might occasionally come across an oddity along a barbed-wire fence: a series of insects, mice or even small birds […]

The post Tiny, fierce and disappearing: breeding program aims to help the loggerhead shrike appeared first on Smithsonian Insider.

Named for Charles Darwin, the only known specimen of a newly discovered beetle, Darwinylus marcosi, died in a sticky battle in a gob of tree […]

The post Beetle and pollen trapped in 105 million-year-old amber reveal fourth major pollination mode in mid-Mesozoic appeared first on Smithsonian Insider.

On Earth Day weekend, the Smithsonian will convene the first Earth Optimism Summit, a three-day event featuring more than 150 scientists, thought leaders, philanthropists, conservationists […]

The post Smithsonian To Convene Earth Optimism Summit April 21–23 appeared first on Smithsonian Insider.

Zebra mussels in the Great Lakes, lionfish in the Atlantic and pythons in the Everglades: Large creatures like these generally draw the spotlight when talking […]

The post DNA is trusty new weapon for detecting slime nets and other invasive marine parasites appeared first on Smithsonian Insider.

A tiny invasive insect from Asia might have an effect on Chesapeake Bay waters. The emerald ash borer is killing millions of ash trees in […]

The post Invasive ash borer found in Smithsonian Environmental Research Center forest; ash deaths may impact Chesapeake waters appeared first on Smithsonian Insider.

Corn, known also as maize, is a vital crop in the U.S. and throughout the Americas. First domesticated in Mexico some 9,000 years ago, scientists […]

The post Study dates corn as staple crop in Central America beginning 4,300 years ago appeared first on Smithsonian Insider.

Each year from summer into fall, ornamental crape myrtle trees in the southern and central U.S. lay out a visual feast of vibrant flowers in […]

The post Crape myrtle trees aren’t native to the US, but hungry native birds still find them tasty 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.

An elementary method is described for finding the coordination sequences for a tiling, based on coloring the underlying graph. The first application is to the two kinds of vertices (tetravalent and trivalent) in the Cairo (or dual-32.4.3.4) tiling. The coordination sequence for a tetravalent vertex turns out, surprisingly, to be 1, 4, 8, 12, 16, …, the same as for a vertex in the familiar square (or 44) tiling. The authors thought that such a simple fact should have a simple proof, and this article is the result. The method is also used to obtain coordination sequences for the 32.4.3.4, 3.4.6.4, 4.82, 3.122 and 34.6 uniform tilings, and the snub-632 tiling. In several cases the results provide proofs for previously conjectured formulas.

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.

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.

The Open Banking Report 2019 clarifies the role of key key-players in a post-September 14th world and assesses how the landscape has shifted within Europe and beyond.

Individual white paper containing all the latest updates to the Open Banking Global State of Play. Research conducted by The Paypers and Innopay

An intuitive method is presented for detecting pseudosymmetries in Z' > 1 cases as a complement to well-proven strategies already available in the literature. It is based in the simple idea that the mid-points between equivalent atoms in symmetrically related mol­ecules are disposed according to simple well-known patterns, which are easily recognizable by optical inspection. A number of Z' = 4 cases in the literature are analyzed, which allows some of the potentialities of the method to be revealed.

The inversion of X-ray reflectivity to reveal the topography of a one-dimensional interface is evaluated through model calculations.

Combining sodium hydride with some solvents can be a bad idea, as a group of researchers from Corteva Agriscience and Dow Chemical remind the chemistry community in Organic Process Research & Development ,(2019, DOI: 10.1021/acs.oprd.9b00276). Reports of explosions from combining NaH with a polar aprotic solvent such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide […]

The post Don’t mix sodium hydride with polar aprotic solvents appeared first on CENtral Science.

(The Paypers) SnapPay has announced the availability of facial recognition payment technology for North...

UK-based banks have received around 100,000 applications in a single day after The Bounce Back Loans scheme for small businesses was released.

Su Ming Sun
Apr 16, 2020; 0:jcs.237628v1-jcs.237628
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National Science Foundation-funded engineers have developed a mathematical framework that can turn any sheet of material into any prescribed shape, inspired by the paper craft kirigami (from the Japanese, kiri, meaning to cut and kami, meaning paper). Unlike its better-known cousin origami, which uses folds to shape paper, kirigami relies on a pattern of cuts in a flat paper sheet to change its flexibility and allow it to morph into 3D shapes. Artists have long used this artform to create everything from pop-up cards to castles and dragons. This research follows previous work by the researchers that characterized how origami-based patterns could be used as building blocks to create almost any three-dimensional curved shape. Next the researchers aim to explore how to combine cuts and folds to achieve any shape with a given set of properties, thus linking origami and kirigami.

Image credit: Harvard SEAS