Nearly 60 million years ago rainforests prospered at temperatures that were 3-5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels.

The post Plant diversity in tropical forests increased during ancient global warming event appeared first on Smithsonian Insider.

For the first time researchers from the Smithsonian, South Dakota State University and the University of Nebraska described the immature stages of the switchgrass moth, first collected in Denver in 1910.

The post Potential biofuel pest, the switchgrass moth, under renewed scrutiny of entomologists appeared first on Smithsonian Insider.

Candy Feller, senior ecologist at the Smithsonian Environmental Research Center in Edgewater, Md., will lead an effort to track more than 100 miles of Florida mangrove forests that are encroaching on salt marshes to the north.

The post NASA to help Smithsonian botanists track northern creep of Florida mangroves appeared first on Smithsonian Insider.

A new study shows that as climate change enhances tree growth in tropical forests, the resulting increase in litterfall could stimulate soil micro-organisms leading to a release of stored soil carbon.

The post Increased tropical forest growth may result in release of stored carbon in the soil appeared first on Smithsonian Insider.

It is one of the rarest shrubs in the southeastern United States but for scientists trying to save it, the critically endangered Michaux’s sumac (Rhus michauxii) is not cooperating.

The post Super tough seed coat keeps Michaux’s sumac on critically endangered list appeared first on Smithsonian Insider.

Older forests with just the right fungi may be secret to saving these vulnerable plants.

The post Fungi-filled forests are critical if endangered orchids are to thrive appeared first on Smithsonian Insider.

Katie Cramer is a MarineGEO Post-Doctoral Fellow and travels to Smithsonian Tropical Research Institute in Panama throughout the year to conduct research. Her recent paper […]

The post Q&A: Katie Cramer on the long term human impact on coral reefs in Caribbean Panama appeared first on Smithsonian Insider.

As mangrove trees lose ground to deforestation and urban sprawl, one development seems to be giving them a boost: climate change. Fewer winter cold snaps […]

The post Mangroves creep north in response to warmer temperatures appeared first on Smithsonian Insider.

What plant species has just been discovered but is almost gone? Bidens meyeri–a just discovered flowering plant from the small South Pacific island of Rapa, […]

The post New South Pacific cliff flower is critically endangered appeared first on Smithsonian Insider.

Why do we love orchids so much? Tom Mirenda, Smithsonian Gardens orchid collection specialist, believes it is partly because orchids seem to look back at […]

The post 5 Crazy Things You Didn’t Know About Orchids appeared first on Smithsonian Insider.

We know some types of fungi turn ants into zombies, but fungi are not always the bad guys. In the case of orchids, fungi are […]

The post The Secret Life of Orchids – Part I: Fungi appeared first on Smithsonian Insider.

Orchids are beautiful, but their beauty can be deceiving. Most orchids don’t have any nectar, yet they cheat their pollinators into thinking that they do […]

The post The Secret Life of Orchids – Part II: Pollinators appeared first on Smithsonian Insider.

Orchids account for 10 percent of the world’s plant species, making them the largest plant family. They act as indicators of the health of ecosystems […]

The post The Secret Life of Orchids – Part III: Conservation appeared first on Smithsonian Insider.

How much is a wetland worth? It’s a question that has plagued policymakers, scientists and other leaders looking to protect their communities and slow down […]

The post New report enables creation of carbon credits for restored wetlands appeared first on Smithsonian Insider.

Strategically placed honeybee hives can deter African elephants from raiding crops, but the hives must be actively managed by beekeepers to work, according to a […]

The post Study: Managed beehives can discourage crop-raiding elephants appeared first on Smithsonian Insider.

Skinny lines of ants snake through the rainforest carrying leaves and flowers above their heads—fertilizer for industrial-scale, underground fungus farms. Soon after the dinosaur extinctions […]

The post Some ants still trying to get crop domestication right appeared first on Smithsonian Insider.

Fort Pierce, Fla. – Fall in southern Florida is festival season: when the weather stops being oppressively hot and 70 degrees is positively autumnal.  On […]

The post Annual Smithsonian-led science festival draws crowds in Fort Pierce, Florida appeared first on Smithsonian Insider.

Internet and phone connections are essential for effective communicators and for success in business. New results from the Smithsonian Tropical Research Institute in Panama show […]

The post Ant bridges connect tropical tree crowns appeared first on Smithsonian Insider.

Coastal marine environments are impacted by human disturbance. Dock pilings allow MarineGEO researchers to study these impacts in a standardized way around the world to […]

The post The incredible marine diversity under boat docks appeared first on Smithsonian Insider.

A newly discovered Hawaiian tree recently had the distinction of being added to the International Union for the Conservation of Nature’s Red List of Critically […]

The post Newly named, Hawaiian tree species already critically endangered appeared first on Smithsonian Insider.

Rainforests on infertile wet soils support more than half of all plant species. Shrublands on infertile dry soils in southwestern Australia, jokingly called “knee-high tropical […]

The post Microbes rule in ‘knee-high tropical rainforests’ appeared first on Smithsonian Insider.

Is it foolish to be optimistic about our environment and its future prospects? Every day, we hear dire warnings about the health of the planet […]

The post The Argument for Environmental Optimism: Opinion by Smithsonian Secretary David J. Skorton appeared first on Smithsonian Insider.

The post Global forest network cracks the case of tropical biodiversity 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.

To catch lizards on the offshore islands close to St. Croix in the Caribbean, Smithsonian herpetologist Nicole Angeli uses a lasso of thread looped at […]

The post Mongooses wiped them out. Now Nicole Angeli wants the St. Croix ground lizard home again appeared first on Smithsonian Insider.

Long before colonists landed on the shores of New England, Native Americans harvested cranberries from peaty bogs and marshes. Following the Pilgrims reliance on the […]

The post The cranberry: America’s founding fruit appeared first on Smithsonian Insider.

No green thumb? You don’t need to water these dazzling orchids to enjoy them. More than 8,000 living specimens in the Smithsonian Gardens Orchid Collection […]

The post See thousands of orchids in incredible detail in the Smithsonian’s newly digitized collection 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 article aims to encourage practitioners, young and seasoned, by enhancing their structure-determination toolboxes with a selection of tips and tricks on recognizing and handling aspects of data collection, structure modelling and refinement, and the interpretation of results.

In the first reported crystal structure involving the potential ligand N,N',N''-tris­(2-pyridin­yl)-1,3,5-benzene­tricarboxamide, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules via their amide groups into slanted ladder-like chains. Only two of the three amide groups in the mol­ecule are involved in hydrogen bonding, which influences the degree of out-of-plane twisting at each amide group.

In the structure of the title salt, second-order Jahn–Teller distortion of the coordination octa­hedra around V ions is reflected by coexistence of short V—O bonds and trans-positioned long V—F bonds, with four equatorial V—F distances being inter­mediate in magnitude. Hydrogen bonding of the anions is restricted to F-atom acceptors only, with particularly strong N–H⋯F inter­actions [N⋯F = 2.5072 (15) Å] established by axial and cis-positioned equatorial F atoms.

The crystal structure of vanthoffite, Na6Mg(SO4)4, was redetermined and refined with anisotropic displacement parameters for all atoms. Here, for the first time, we give its detailed description.

The cationic cyclo­metallated iridium(III) complex [Ir(C9H7N2)2(C12H8N2)](PF6) has been synthesized and crystallized by the inter-diffusion method. It contains an unknown number of solvent mol­ecules and has a different space-group symmetry (C2/c) structure than its solvatomorph (P21/c).

The new copper(II) complex [CuLCl2]2, where L is a product of Schiff base condensation between methyl­amine and 2-pyridine­carbaldehyde, is built of discrete centrosymmetric dimers.

The asymmetric unit of the title compound contains two independent mol­ecules, consisting of perimidine and phenol units, which are linked through an N—H⋯O hydrogen bond. Intra­molecular O—H⋯N hydrogen bonds are observed in both independent mol­ecules.

The title compound, 1-(2,5-di­meth­oxy­phen­yl)-2,2,6,6-tetra­methyl­piperidine, was synthesized as a side-product during the synthesis of the inter­mediate, methyl 3,6-dimeth­oxy-2-(2-meth­oxy-2-oxoeth­yl)benzoate, necessary for the total synthesis of the isocoumarin 5,8-dimeth­oxy-3-methyl-1H-isochromen-1-one.

The title compound exhibits exceptionally weak inter­molecular C—H⋯π hydrogen bonding of the ethynyl groups, with the corresponding H⋯π separations [2.91 (2) and 3.12 (2) Å] exceeding normal vdW distances. This bonding compliments distal contacts of the CH (aliphatic)⋯π type [H⋯π = 3.12 (2)–3.14 (2) Å] to sustain supra­molecular layers.

The dihedral angle between the two aromatic rings of the title compound is 64.12 (14)°. The crystal structure is stabilized by a short Cl⋯H contact, C—Cl⋯π and van der Waals inter­actions.

The title complex, Cu(L)2 or [Cu(C15HF10O2)2], comprising one copper ion and two fully fluorinated ligands (L−), was crystallized with 3,4-ethyl­ene­dioxy­thio­phene (EDOT, C6H6O2S) as a guest mol­ecule to give in a di­chloro­methane solution a unique co-crystal, Cu(L)2·3C6H6O2S.

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.

The structural and nonlinear optical properties of a new anilinium hybrid crystal of chemical formula (C6H7NCl+·NO3−)3 have been investigated. The crystal structure was determined from single-crystal X-ray diffraction measurements performed at a temperature of 100 K which show that the compound crystallizes in a noncentrosymmetric space group (Pna21). The structural analysis was coupled with Hirshfeld surface analysis to evaluate the contribution of the different intermolecular interactions to the formation of supramolecular assemblies in the solid state that exhibit nonlinear optical features. This analysis reveals that the studied compound is characterized by a three-dimensional network of hydrogen bonds and the main contributions are provided by the O...H, C...H, H...H and Cl...H interactions, which alone represent ∼85% of the total contributions to the Hirshfeld surfaces. It is noteworthy that the halogen...H contributions are quite comparable with those of the H...H contacts. The nonlinear optical properties were investigated by nonlinear diffuse femtosecond-pulse reflectometry and the obtained results were compared with those of the reference material LiNbO3. The hybrid crystals exhibit notable second (SHG) and third (THG) harmonic generation which confirms its polarity is generated by the different intermolecular interactions. These measurements also highlight that the THG signal of the new anilinium compound normalized to its SHG counterpart is more pronounced than for LiNbO3.

The methods for X-ray crystal orientation are rapidly evolving towards versatility, fewer goniometry measurements, automation, high accuracy and precision. One method that attracts a lot of attention is energy-dispersive X-ray diffraction (EDXRD) which is based on detecting reflections from crystallographic planes in a crystal at fixed angles of a parallel polychromatic X-ray incident beam. In theory, an EDXRD peak can move in a diffraction pattern as a function of a crystallographic plane d-spacing and its orientation relative to a fixed direction in space can change also. This is equivalent to the possibility of measuring the orientation of single crystals. The article provides a modeling for the EDXRD method whose main feature is the nonmoving crystal in the sense of traditional goniometry where the angle measurements of diffracting planes are a must. The article defines the equation of orientation for the method and shows the derivation in great detail. It is shown that the exact solutions of the equations can be obtained using the generalized reduced gradient method, a mathematical subroutine that is implemented in Excel software. The significance and scientific impact of the work are discussed along with the validated tested results.

One of the essential components of molecular electronic circuits are switching elements that are stable in two different states and can ideally be switched on and off many times. Here, distinct buckminsterfullerenes within a self-assembled monolayer, forming a two-dimensional dodecagonal quasicrystal on a Pt-terminated Pt3Ti(111) surface, are identified to form well separated molecular rotational switching elements. Employing scanning tunneling microscopy, the molecular-orbital appearance of the fullerenes in the quasicrystalline monolayer is resolved. Thus, fullerenes adsorbed on the 36 vertex configuration are identified to exhibit a distinctly increased mobility. In addition, this finding is verified by differential conductance measurements. The rotation of these mobile fullerenes can be triggered frequently by applied voltage pulses, while keeping the neighboring molecules immobile. An extensive analysis reveals that crystallographic and energetic constraints at the molecule/metal interface induce an inequality of the local potentials for the 36 and 32.4.3.4 vertex sites and this accounts for the switching ability of fullerenes on the 36 vertex sites. Consequently, a local area of the 8/3 approximant in the two-dimensional fullerene quasicrystal consists of single rotational switching fullerenes embedded in a matrix of inert molecules. Furthermore, it is deduced that optimization of the intermolecular interactions between neighboring fullerenes hinders the realization of translational periodicity in the fullerene monolayer on the Pt-terminated Pt3Ti(111) surface.

To date X-ray protein crystallography is the most successful technique available for the determination of high-resolution 3D structures of biological molecules and their complexes. In X-ray protein crystallography the structure of a protein is refined against the set of observed Bragg reflections from a protein crystal. The resolution of the refined protein structure is limited by the highest angle at which Bragg reflections can be observed. In addition, the Bragg reflections alone are typically insufficient (by a factor of two) to determine the structure ab initio, and so prior information is required. Crystals formed from an imperfect packing of the protein molecules may also exhibit continuous diffraction between and beyond these Bragg reflections. When this is due to random displacements of the molecules from each crystal lattice site, the continuous diffraction provides the necessary information to determine the protein structure without prior knowledge, to a resolution that is not limited by the angular extent of the observed Bragg reflections but instead by that of the diffraction as a whole. This article presents an iterative projection algorithm that simultaneously uses the continuous diffraction as well as the Bragg reflections for the determination of protein structures. The viability of this method is demonstrated on simulated crystal diffraction.