The title compound, C22H17NO2·C3H7NO, was synthesized by condensation of an aromatic aldehyde with a secondary amine and subsequent reduction. It was crystallized from a di­methyl­formamide solution as a monosolvate, C22H17NO2·C3H7NO. The aromatic mol­ecule is non-planar with a dihedral angle between the mean planes of the aniline moiety and the methyl anthracene moiety of 81.36 (8)°. The torsion angle of the Car­yl—CH2—NH—Car­yl backbone is 175.9 (2)°. The crystal structure exhibits a three-dimensional supra­molecular network, resulting from hydrogen-bonding inter­actions between the carb­oxy­lic OH group and the solvent O atom as well as between the amine functionality and the O atom of the carb­oxy­lic group and additional C—H⋯π inter­actions. Hirshfeld surface analysis was performed to qu­antify the inter­molecular inter­actions.

In this work, two methods of high-resolution X-ray data refinement: multipole refinement (MM) and Hirshfeld atom refinement (HAR) – together with X-ray wavefunction refinement (XWR) – are applied to investigate the refinement of positions and anisotropic thermal motion of hydrogen atoms, experiment-based reconstruction of electron density, refinement of anharmonic thermal vibrations, as well as the effects of excluding the weakest reflections in the refinement. The study is based on X-ray data sets of varying quality collected for the crystals of four quinoline derivatives with Cl, Br, I atoms and the -S-Ph group as substituents. Energetic investigations are performed, comprising the calculation of the energy of intermolecular interactions, cohesive and geometrical relaxation energy. The results obtained for experimentally derived structures are verified against the values calculated for structures optimized using dispersion-corrected periodic density functional theory. For the high-quality data sets (the Cl and -S-Ph compounds), both MM and XWR could be successfully used to refine the atomic displacement parameters and the positions of hydrogen atoms; however, the bond lengths obtained with XWR were more precise and closer to the theoretical values. In the application to the more challenging data sets (the Br and I compounds), only XWR enabled free refinement of hydrogen atom geometrical parameters, nevertheless, the results clearly showed poor data quality. For both refinement methods, the energy values (intermolecular interactions, cohesive and relaxation) calculated for the experimental structures were in similar agreement with the values associated with the optimized structures – the most significant divergences were observed when experimental geometries were biased by poor data quality. XWR was found to be more robust in avoiding incorrect distortions of the reconstructed electron density as a result of data quality issues. Based on the problem of anharmonic thermal motion refinement, this study reveals that for the most correct interpretation of the obtained results, it is necessary to use the complete data set, including the weak reflections in order to draw conclusions.

During single-crystal-to-single-crystal (SCSC) phase transitions, a polymorph of a compound can transform to a more stable form while remaining in the solid state. By understanding the mechanism of these transitions, strategies can be developed to control this phenomenon. This is particularly important in the pharmaceutical industry, but also relevant for other industries such as the food and agrochemical industries. Although extensive literature exists on SCSC phase transitions in inorganic crystals, it is unclear whether their classications and mechanisms translate to molecular crystals, with weaker interactions and more steric hindrance. A comparitive study of SCSC phase transitions in aliphatic linear-chain amino acid crystals, both racemates and quasi-racemates, is presented. A total of 34 transitions are considered and most are classified according to their structural change during the transition. Transitions without torsional changes show very different characteristics, such as transition temperature, enthalpy and free energy, compared with transitions that involve torsional changes. These differences can be rationalized using classical nucleation theory and in terms of a difference in mechanism; torsional changes occur in a molecule-by-molecule fashion, whereas transitions without torsional changes involve cooperative motion with multiple molecules at the same time.

Neisseria meningitidis is carried by nearly a billion humans, causing developmental impairment and over 100 000 deaths a year. A quinol-dependent nitric oxide reductase (qNOR) plays a critical role in the survival of the bacterium in the human host. X-ray crystallographic analyses of qNOR, including that from N. meningitidis (NmqNOR) reported here at 3.15 Å resolution, show monomeric assemblies, despite the more active dimeric sample being used for crystallization. Cryo-electron microscopic analysis of the same chromatographic fraction of NmqNOR, however, revealed a dimeric assembly at 3.06 Å resolution. It is shown that zinc (which is used in crystallization) binding near the dimer-stabilizing TMII region contributes to the disruption of the dimer. A similar destabilization is observed in the monomeric (∼85 kDa) cryo-EM structure of a mutant (Glu494Ala) qNOR from the opportunistic pathogen Alcaligenes (Achromobacter) xylosoxidans, which primarily migrates as a monomer. The monomer–dimer transition of qNORs seen in the cryo-EM and crystallographic structures has wider implications for structural studies of multimeric membrane proteins. X-ray crystallographic and cryo-EM structural analyses have been performed on the same chromatographic fraction of NmqNOR to high resolution. This represents one of the first examples in which the two approaches have been used to reveal a monomeric assembly in crystallo and a dimeric assembly in vitrified cryo-EM grids. A number of factors have been identified that may trigger the destabilization of helices that are necessary to preserve the integrity of the dimer. These include zinc binding near the entry of the putative proton-transfer channel and the preservation of the conformational integrity of the active site. The mutation near the active site results in disruption of the active site, causing an additional destabilization of helices (TMIX and TMX) that flank the proton-transfer channel helices, creating an inert monomeric enzyme.

Across all branches of science, medicine and engineering, high-resolution microscopy is required to understand functionality. Although optical methods have been developed to `defeat' the diffraction limit and produce 3D images, and electrons have proven ever more useful in creating pictures of small objects or thin sections, so far there is no substitute for X-ray microscopy in providing multiscale 3D images of objects with a single instrument and minimal labeling and preparation. A powerful technique proven to continuously access length scales from 10 nm to 10 µm is ptychographic X-ray computed tomography, which, on account of the orthogonality of the tomographic rotation axis to the illuminating beam, still has the limitation of necessitating pillar-shaped samples of small (ca 10 µm) diameter. Large-area planar samples are common in science and engineering, and it is therefore highly desirable to create an X-ray microscope that can examine such samples without the extraction of pillars. Computed laminography, where the axis of rotation is not perpendicular to the illumination direction, solves this problem. This entailed the development of a new instrument, LamNI, dedicated to high-resolution 3D scanning X-ray microscopy via hard X-ray ptychographic laminography. Scanning precision is achieved by a dedicated interferometry scheme and the instrument covers a scan range of 12 mm × 12 mm with a position stability of 2 nm and positioning errors below 5 nm. A new feature of LamNI is a pair of counter-rotating stages carrying the sample and interferometric mirrors, respectively.

The Inorganic Crystal Structure Database (ICSD) is the world's largest database of fully evaluated and published crystal structure data, mostly obtained from experimental results. However, the purely experimental approach is no longer the only route to discover new compounds and structures. In the past few decades, numerous computational methods for simulating and predicting structures of inorganic solids have emerged, creating large numbers of theoretical crystal data. In order to take account of these new developments the scope of the ICSD was extended in 2017 to include theoretical structures which are published in peer-reviewed journals. Each theoretical structure has been carefully evaluated, and the resulting CIF has been extended and standardized. Furthermore, a first classification of theoretical data in the ICSD is presented, including additional categories used for comparison of experimental and theoretical information.

Insights were obtained into the structure of the 4-hydroxy-tetrahydrodipicolinate synthase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV and the phylogeny of the aminotransferase pathway for the biosynthesis of lysine.

The crystal structure of Pseudomonas aeruginosa Fis is composed of an N-terminal flexible loop and a C-terminal helix–turn–helix motif.

The structure of the Pseudomonas aeruginosa T6SS PldB immunity protein PA5086 is reported at 1.9 Å resolution. Comparison of PA5086 with its homologs PA5087 and PA5088 showed great similarities in sequence and structure, but vast divergences in electrostatic potential surfaces.

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.

It’s not an exaggeration to say Hedrick was ecstatic when she peered into her inverted phase contrast microscope and found "Amphisolenia quadrispina" floating in her sample. “For 20 years I’ve been hoping to see something like this,” she says.

The post From the Bay of Bengal, a dinoflagellate makes its way to the Smithsonian appeared first on Smithsonian Insider.

Describing a species is a serious undertaking. In the case of T. acutus, Coats and his collaborators documented its microscopic life cycle, conducted extensive DNA analysis and unearthed scientific papers dating back to 1873—when parasitic dinoflagellates were first noted by German scientist Ernst Haeckel.

The post Introducing the parasitic dinoflagellate: Tintinnophagus acutus appeared first on Smithsonian Insider.

Astronomers are piecing together the reasons for these huge energy outputs, while sorting out why our own galaxy is so modest. The two primary suspects are bursts of star formation that produce many hot young stars, and processes associated with accretion of material onto a supermassive black hole at a galaxy's nucleus.

The post Luminosity of extreme galaxy most likely driven by star formation 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.

The 5.8-magnitude earthquake that shook the eastern United States on the afternoon of Tuesday, Aug. 23, caused minor damage to some of the Smithsonian's natural history collections. All public Smithsonian museums are open and have been determined safe for visitors and staff.

The post Earthquake causes minor damage to Smithsonian natural history collections appeared first on Smithsonian Insider.

The fossil represents the youngest nodosaur ever discovered, and the only known specimen of a new genus and species of dinosaur that lived approximately 110 million years ago during the Early Cretaceous Era.

The post New dinosaur species named from hatchling fossil donated to National Museum of Natural History appeared first on Smithsonian Insider.

An excavation at a site in South Africa has unearthed the 190-million-year-old dinosaur nesting site of the prosauropod dinosaur Massospondylus–revealing significant clues about the evolution of complex reproductive behavior in early dinosaurs.

The post 190-million-year-old dinosaur nesting site discovered in South Africa appeared first on Smithsonian Insider.

The National Museum of Natural History will construct a new dinosaur exhibition hall made possible by a $35 million donation from David H. Koch, executive vice president of Koch Industries and philanthropist.

The post $35-million donation will build new dinosaur hall at National Museum of Natural History appeared first on Smithsonian Insider.

A July 12 news alert from NASA indicates a X1.4 class solar flare erupted from the center of the Sun, peaking July 12 at 12:52 P.M.

The post Coronal mass ejection from July 12 solar flare headed toward Earth; minor geomagnetic storm activity predicted appeared first on Smithsonian Insider.

The National Museum of Natural History announced this summer that it has reached a 50-year loan agreement with the U.S. Army Corps of Engineers to […]

The post T. rex to rule Dinosaur Hall in Washington, D.C. appeared first on Smithsonian Insider.

  This image is a close-up of the skull of the Tyrannosaurus rex skeleton known as the Wankel T. rex which was installed in front […]

The post T-rex to rule Dinosaur Hall appeared first on Smithsonian Insider.

Finding a fossil is the first step, recognizing it for what it truly is, is the real challenge. While closely studying three fossil skeletons from […]

The post One Scary Chicken—New species of large, feathered dinosaur discovered appeared first on Smithsonian Insider.

When some of the world’s largest mammals come your way, most animals steer clear. Not the genet. The small cat-like carnivore was captured on film […]

The post Maybe it’s safer riding a rhino. Genet expert poses new ideas on the mammal’s hitchhiking behavior appeared first on Smithsonian Insider.

Death-associated protein kinase 1 (DAPK1) is a serine/threonine protein kinase that regulates apoptosis and autophagy. DAPK1 is considered to be a therapeutic target for amyloid-β deposition, endometrial adenocarcinomas and acute ischemic stroke. Here, the potent inhibitory activity of the natural anthraquinone purpurin against DAPK1 phosphorylation is shown. Thermodynamic analysis revealed that while the binding affinity of purpurin is similar to that of CPR005231, which is a DAPK1 inhibitor with an imidazopyridazine moiety, the binding of purpurin was more enthalpically favorable. In addition, the inhibition potencies were correlated with the enthalpic changes but not with the binding affinities. Crystallographic analysis of the DAPK1–purpurin complex revealed that the formation of a hydrogen-bond network is likely to contribute to the favorable enthalpic changes and that stabilization of the glycine-rich loop may cause less favorable entropic changes. The present findings indicate that purpurin may be a good lead compound for the discovery of inhibitors of DAPK1, and the observation of enthalpic changes could provide important clues for drug development.

The post The Forgotten Dinosaur Hunter 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 Natural History Museum curator Nick Pyenson explains how scientists know what dinosaurs and other extinct animals ate appeared first on Smithsonian Insider.

The National Museum of Natural History in Washington, D.C., has closed its Dinosaur Hall for a five-year renovation. But before the overhaul can begin, the […]

The post How do you dismantle a dinosaur? appeared first on Smithsonian Insider.

How do you bring a nearly complete T. rex back to life? You send the fossils to Canada where craftsmen create a creature of steel. […]

The post First Look: The Smithsonian builds a dinosaur appeared first on Smithsonian Insider.

Amateur paleontologist, Ray Stanford, describes his experience of discovering the impression of a dinosaur and determining that it was a new species. This video is […]

The post What is it like to discover a new dinosaur? appeared first on Smithsonian Insider.

This year’s El Niño event is one of the strongest on record and is still ramping up. Large parts of the tropics are turning into […]

The post Major El Nino Perfect opportunity for Global Change Research appeared first on Smithsonian Insider.

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.

An efficient synthesis of 1-aryl­isochromeno[3,4-d][1,2,3]triazol-5(1H)-ones, involving the diazo­tization of 3-amino-4-aryl­amino-1H-isochromen-1-ones in weakly acidic solution, has been developed and the spectroscopic characterization and crystal structures of four examples are reported. The mol­ecules of 1-phenyl­isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C15H9N3O2, (I), are linked into sheets by a combination of C—H⋯N and C—H⋯O hydrogen bonds, while the structures of 1-(2-methyl­phen­yl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C16H11N3O2, (II), and 1-(3-chloro­phen­yl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C15H8ClN3O2, (III), each contain just one hydrogen bond which links the mol­ecules into simple chains, which are further linked into sheets by π-stacking inter­actions in (II) but not in (III). In the structure of 1-(4-chloro­phen­yl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, (IV), isomeric with (III), a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds links the mol­ecules into sheets. When com­pound (II) was exposed to a strong acid in methanol, qu­anti­tative conversion occurred to give the ring-opened transesterification product methyl 2-[4-hy­droxy-1-(2-methyl­phen­yl)-1H-1,2,3-triazol-5-yl]benzoate, C17H15N3O3, (V), where the mol­ecules are linked by paired O—H⋯O hydrogen bonds to form centrosymmetric dimers.

Video of the B9 robot from "Lost In Space" and his most famous catchphrases.; Credit: timtomp (via YouTube)

Robert Kinoshita, the Los Angeles native who designed the iconic robots from "Lost in Space" and "Forbidden Planet," has passed away. He was 100 years old.

Konishita died Dec. 9 at a Torrance nursing home, according to the Hollywood Reporter, citing family friend Mike Clark. His creations included "Forbidden Planet's" Robby the Robot, the B9 robot from "Lost in Space," Tobor from "Tobor the Great" and more. Kinoshita also created "Lost in Space's" iconic flying-saucer-shaped Jupiter 2 spaceship.

Kinoshita built the original miniature prototype of Robby the Robot out of wood and plastic by combining several different concepts, according to the Reporter; the Rafu Shimpo reported that he struggled with the design.

"I thought, what the hell. We’re wasting so much time designing and drawing one sketch after another. I said to myself, I’m going to make a model," Kinoshita told the Rafu Shimpo in a 2004 interview. "Then one day, the art director sees the model. He says, ‘Give me that thing.’ He grabbed it and ran. ... Ten minutes later, he comes running back and puts the model back on my desk and says, ‘Draw it!’"

Watch Kinoshita and his colleagues talking about the construction of Robby the Robot:

Robby the Robot's construction

The 1956 classic sci-fi movie "Forbidden Planet" — based on Shakespeare's "The Tempest" — went on to be nominated for a special effects Oscar.

Kinoshita later served as art director on the 1960s sci-fi TV series "Lost in Space," creating the arm-flailing robot — named B9 — who delivered the classic line "Danger! Danger, Will Robinson!" That robot received as much fan mail as the actual humans on the show, according to the Reporter.

Watch the robot's feud with "Lost in Space's" Dr. Smith:

The robot vs. Dr. Smith

The "Lost in Space" robot even inspired a B9 Robot Builders Club, featured in Forbes. Kinoshita sent a message in 2000 to the club, thanking them for their support for the robot he originally nicknamed "Blinky."

"I'm truly flabbergasted and honored by your support for 'Blinky!' It's a well-designed little beauty," Kinoshita wrote. "Your thoughtful remembrance is something we designers seldom are lucky enough to receive."

Kinoshita described the thought process behind its design in a 1998 interview.

"You're laying in bed, and something comes to you," he said. "Until, finally, you get to a point where you say, 'This could work,' 'OK, let's see what the boss man says.' And you present it to him."

He told the Rafu Shimpo that he tried to create his robots to disguise the fact that there was a person inside. "I tried to camouflage it enough so you’d wonder where the hell the human was," he said.

Both the Japanese-American Kinoshita and his wife, Lillian, were sent to an Arizona internment camp during World War II, though they were able to get out before the end of the war and moved to Wisconsin, according to the Reporter.

While in Wisconsin, Kinoshita learned industrial design and plastic fabrication, designing washing machines for the Army and Air Force before returning to California, according to the Rafu Shimpo.

Kinoshita said that he had to overcome racial prejudice to break into working in Hollywood.

Kinoshita attributed his long life to clean living — along with daily doses of apple cider vinegar, family friend Clark told the Reporter.

Kinoshita also worked as a designer and art director on numerous classic TV shows, including "Kojak," "Barnaby Jones," "Hawaii Five-O," "Bat Masterson," "Sea Hunt," "Tombstone Territory," "Star Trek" creator Gene Roddenberry's "Planet Earth" and more, according to his IMDB. His last TV show was 1984's "Cover Up."

Kinoshita grew up in Boyle Heights, according to the Reporter, attending Maryknoll Japanese Catholic School, Roosevelt High School and USC's School of Architecture. His career began with work on 1937's "100 Men and a Girl." Kinoshita graduated cum laude from USC, according to the Rafu Shimpo.

Watch Kinoshita speak at his 95th birthday gathering with the B9 Robot Builders Club. He said he hoped to make it to 100, and he ended up doing so.

Kinoshita's 95th birthday speech

This content is from Southern California Public Radio. View the original story at SCPR.org.

Cancer-causing chemicals that occur naturally in foods are far more numerous in the human diet than synthetic carcinogens, yet both types are consumed at levels so low that they currently appear to pose little threat to human health, a committee of the National Research Council said in a report released today.

To ensure that minority students who are poorly prepared for school are not assigned to special education for that reason, educators should be required to first provide them with high-quality instruction and social support in a general education classroom before making a determination that special education is needed.

Racial and ethnic minorities tend to receive lower-quality health care than whites do, even when insurance status, income, age, and severity of conditions are comparable.

A new report from the National Research Council has upheld the listing of styrene as “reasonably anticipated to be a human carcinogen” in the National Toxicology Program’s 12th Report on Carcinogens (RoC).

A new report from the National Research Council has upheld the listing of formaldehyde as “known to be a human carcinogen” in the National Toxicology Program 12th Report on Carcinogens (RoC).

The National Academy of Sciences (NAS) announces the appointment of May R. Berenbaum as Editor-in-Chief of the Proceedings of the National Academy of Sciences (PNAS), the official journal of the Academy. Berenbaum will begin the editorship on January 1, 2019.

Higher education leaders, policymakers, and the private sector should take a range of actions to strengthen STEM programs and degree attainment in the nation’s Minority Serving Institutions (MSIs), says a new report from the National Academies of Sciences, Engineering, and Medicine.

A new report from the National Academies of Sciences, Engineering and Medicine finds that the U.S. Environmental Protection Agencys (EPA) approach to its ongoing Integrated Risk Information System (IRIS) assessment plan is appropriate for synthesizing the scientific evidence and quantifying estimates of inorganic arsenic toxicity.

Only about two or three small birds are killed by wind turbines each year for every 225-300 houses supplied with renewable energy, new research suggests. The study collated data from 116 US and Canadian studies on 156 species of passerines (small birds). The study suggests some species are affected more than others, but that wind turbines generally have only a minor impact on these small-bird populations.

Neonicotinoid and fipronil insecticides have a range of impacts on birds, mammals and fish, a new review of scientific literature has found. A house sparrow would need to eat just one and a half beet seeds treated with a common neonicotinoid to receive a lethal dose, for instance. The insecticides may also have equally important effects on vertebrate wildlife, such as reducing insect prey and hence food supply.

Beetles that are helpful to farmers can be poisoned if they feed on slugs that have eaten crops treated with neonicotinoids, a new study reports. The slugs themselves are not harmed by neonicotinoids. In American field trials, researchers found that plots planted with neonicotinoid-treated soybeans contained more slugs, fewer beetle predators and had 5% lower yields. The insecticide may be reducing the beetles’ effectiveness as a natural control of slug pests.

Honeybees and bumblebees prefer feeding on nectar laced with certain neonicotinoid pesticides to uncontaminated food, new research has shown. Far from the predictions of some, that bees would avoid food contaminated with neonicotinoid pesticides if given the choice, a new study has shown that bees did not avoid any of the three most common neonicotinoids: imidacloprid, thiamethoxam or clothianidin. Furthermore, they showed a preference for imidacloprid and thiamethoxam over uncontaminated sugar solutions.

Neonicotinoids are pesticides applied to plants to protect them from insects. The use of neonicotinoids may lead to contamination of aquatic environments through, among other routes, the input of contaminated plant material into waterways. While it is well established that direct exposure to contaminated water endangers aquatic invertebrates, scientists have now published findings indicating that dietary exposure through the consumption of contaminated plant material puts leaf-shredding species at increased risk. The researchers recommend that policymakers registering systemic insecticides (those whose active ingredients are transported throughout the plant tissues) consider dietary exposure, and its potential implications for ecosystem integrity, in addition to other exposure pathways.