rc 'Rumbling' felt during Ardnamurchan earthquake - BBC News By www.bbc.com Published On :: Tue, 17 Mar 2020 07:00:00 GMT 'Rumbling' felt during Ardnamurchan earthquake BBC News Full Article
rc Coronavirus: Is lockdown an opportunity for scientific research? - sciencefocus.com By www.sciencefocus.com Published On :: Fri, 08 May 2020 07:00:00 GMT Coronavirus: Is lockdown an opportunity for scientific research? sciencefocus.com Full Article
rc Researchers Describe Why Earth's Magnetic North Pole Is Straying Away From Canada Towards Siberia - The Digital Wise By thedigitalwise.com Published On :: Sat, 09 May 2020 06:54:00 GMT Researchers Describe Why Earth's Magnetic North Pole Is Straying Away From Canada Towards Siberia The Digital Wise Full Article
rc Research Centre Finance Administrator job with UNIVERSITY OF LEEDS | 206139 - Times Higher Education (THE) By www.timeshighereducation.com Published On :: Thu, 07 May 2020 05:09:11 GMT Research Centre Finance Administrator job with UNIVERSITY OF LEEDS | 206139 Times Higher Education (THE) Full Article
rc Earthquake rumbles under sea off Norfolk coast | Great Yarmouth News - Great Yarmouth Mercury By www.greatyarmouthmercury.co.uk Published On :: Thu, 23 Apr 2020 07:00:00 GMT Earthquake rumbles under sea off Norfolk coast | Great Yarmouth News Great Yarmouth Mercury Full Article
rc Chirality in Biological Nanospaces: Reactions in Active Sites. By Nilashis Nandi. Pp. 209. CRC Press, 2011. Price £79.99. ISBN 9781439840023. By journals.iucr.org Published On :: Full Article text
rc The crystal structure of the heme d1 biosynthesis-associated small c-type cytochrome NirC reveals mixed oligomeric states in crystallo By journals.iucr.org Published On :: The crystal structure of the c-type cytochrome NirC from Pseudomonas aeruginosa has been determined and reveals the simultaneous presence of monomers and 3D domain-swapped dimers in the same asymmetric unit. Full Article text
rc Crystal structure of bis(1-ethyl-1H-imidazole-κN3)(meso-tetramesitylporphyrinato-κ4N,N',N'',N''')iron(III) perchlorate chlorobenzene sesquisolvate By scripts.iucr.org Published On :: 2019-05-31 In the complex cation of title compound, [Fe(C56H52N4)(C5H8N2)2]ClO4·1.5C6H5Cl, the ironIII atom is coordinated in a distorted octahedral manner by four pyrrole N atoms of the porphyrin ring system in the equatorial plane, and by two N atoms of the 1-ethylimidazole ligands in the axial sites. A disordered perchlorate anion and one and a half chlorobenzene solvent molecules are also present. The cationic complex exhibits a highly ruffled porphyrin core. The average Fe—Np (Np is a porphyrin N atom) bond length is 1.988 (5), and the axial Fe—NIm (NIm is an imidazole N atom) bond lengths are 1.962 (3) and 1.976 (3) Å. The two 1-ethylimidazole ligands are inclined to each other by a dihedral angle of 68.62 (16)°. The dihedral angles between the 1-ethylimidazole planes and the planes of the closest Fe—Np vector are 28.52 (18) and 43.57 (13)°. Intermolecular C—H⋯Cl interactions are observed. Full Article text
rc (E)-6,6'-(Diazene-1,2-diyl)bis(1,10-phenanthrolin-5-ol) trichloromethane disolvate: a superconjugated ligand By scripts.iucr.org Published On :: 2019-07-23 Phenanthroline ligands are important metal-binding molecules which have been extensively researched for applications in both material science and medicinal chemistry. Azobenzene and its derivatives have received significant attention because of their ability to be reversibly switched between the E and Z forms and so could have applications in optical memory and logic devices or as molecular machines. Herein we report the formation and crystal structure of a highly unusual novel diazo-diphenanthroline compound, C24H14N6O2·2CHCl3. Full Article text
rc Crystal structure, Hirshfeld surface analysis and physicochemical characterization of bis[4-(dimethylamino)pyridinium] di-μ-chlorido-bis[dichloridomercurate(II)] By scripts.iucr.org Published On :: 2019-10-03 The title molecular salt, (C7H11N2)2[Hg2Cl6], crystallizes with two 4-(dimethylamino)pyridinium cations (A and B) and two half hexachloridodimercurate(II) anions in the asymmetric unit. The organic cations exhibit essentially the same features with an almost planar pyridyl ring (r.m.s. deviations of 0.0028 and 0.0109 Å), which forms an inclined dihedral angle with the dimethyamino group [3.06 (1) and 1.61 (1)°, respectively]. The dimethylamino groups in the two cations are planar, and the C—N bond lengths are shorter than that in 4-(dimethylamino)pyridine. In the crystal, mixed cation–anion layers lying parallel to the (010) plane are formed through N—H⋯Cl hydrogen bonds and adjacent layers are linked by C—H⋯Cl hydrogen bonds, forming a three-dimensional network. The analyses of the calculated Hirshfeld surfaces confirm the relevance of the above intermolecular interactions, but also serve to further differentiate the weaker intermolecular interactions formed by the organic cations and inorganic anions, such as π–π and Cl⋯Cl interactions. The powder XRD data confirms the phase purity of the crystalline sample. Furthermore, the vibrational absorption bands were identified by IR spectroscopy and the optical properties were studied by using optical UV–visible absorption spectroscopy. Full Article text
rc The first structural characterization of the protonated azacyclam ligand in catena-poly[[[(perchlorato)copper(II)]-μ-3-(3-carboxypropyl)-1,5,8,12-tetraaza-3-azoniacyclotetradecane] bis(per& By scripts.iucr.org Published On :: 2019-10-22 The asymmetric unit of the title compound, catena-poly[[[(perchlorato-κO)copper(II)]-μ-3-(3-carboxypropyl)-1,5,8,12-tetraaza-3-azoniacyclotetradecane-κ4N1,N5,N8,N12] bis(perchlorate)], {[Cu(C13H30N5O2)(ClO4)](ClO4)2}n, (I), consists of a macrocyclic cation, one coordinated perchlorate anion and two perchlorate ions as counter-anions. The metal ion is coordinated in a tetragonally distorted octahedral geometry by the four secondary N atoms of the macrocyclic ligand, the mutually trans O atoms of the perchlorate anion and the carbonyl O atom of the protonated carboxylic acid group of a neighbouring cation. The average equatorial Cu—N bond lengths [2.01 (6) Å] are significantly shorter than the axial Cu—O bond lengths [2.379 (8) Å for carboxylate and average 2.62 (7) Å for disordered perchlorate]. The coordinated macrocyclic ligand in (I) adopts the most energetically favourable trans-III conformation with an equatorial orientation of the substituent at the protonated distal 3-position N atom in a six-membered chelate ring. The coordination of the carboxylic acid group of the cation to a neighbouring complex unit results in the formation of infinite chains running along the b-axis direction, which are crosslinked by N—H⋯O hydrogen bonds between the secondary amine groups of the macrocycle and O atoms of the perchlorate counter-anions to form sheets lying parallel to the (001) plane. Additionally, the extended structure of (I) is consolidated by numerous intra- and interchain C—H⋯O contacts. Full Article text
rc (μ-Di-tert-butylsilanediolato)bis[bis(η5-cyclopentadienyl)methylzirconium] By scripts.iucr.org Published On :: 2019-11-08 The reaction of t-Bu2Si(OH)2 with two equivalents of Cp2Zr(CH3)2 produces the title t-Bu2SiO2-siloxide bridged dimer, [Zr2(CH3)2(C5H5)4(C8H18O2Si)] or [Cp2Zr(CH3)]2[μ-t-Bu2SiO2] (1), where one methyl group is retained per zirconium atom. The same product is obtained at room temperature even when equimolar ratios of the silanediol and Cp2Zr(CH3)2 are used. Attempts to thermally eliminate methane and produce a bridging methylene complex resulted in decomposition. The crystal structure of 1 displays typical Zr—CH3 and Zr—O distances but the Si—O distance [1.628 (2) Å] and O—Si—O angle [110.86 (15)°] are among the largest observed in this family of compounds suggesting steric crowding between the t-Bu substituents of the silicon atom and the cyclopentadienyl groups. The silicon atom lies on a crystallographic twofold axis and both Cp rings are disordered over two orientations of equal occupancy. Full Article text
rc A new pseudopolymorph of perchlorinated neopentasilane: the benzene monosolvate Si(SiCl3)4·C6H6 By scripts.iucr.org Published On :: 2020-01-31 A new pseudopolymorph of dodecachloropentasilane, namely a benzene monosolvate, Si5Cl12·C6H6, is described. There are two half molecules of each kind in the asymmetric unit. Both Si5Cl12 molecules are completed by crystallographic twofold symmetry. One of the benzene molecules is located on a twofold rotation axis with two C—H groups located on this rotation axis. The second benzene molecule has all atoms on a general position: it is disordered over two equally occupied orientations. No directional interactions beyond normal van der Waals contacts occur in the crystal. Full Article text
rc Crystal structure of 1,4,8,11-tetramethyl-1,4,8,11-tetraazoniacyclotetradecane bis(perchlorate) dichloride from synchrotron X-ray data By scripts.iucr.org Published On :: 2020-02-11 The crystal structure of title salt, C14H36N44+·2ClO4−·2Cl−, has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit contains one half-cation (completed by crystallographic inversion symmetry), one perchlorate anion and one chloride anion. A distortion of the perchlorate anion is due to its involvement in hydrogen-bonding interactions with the cations. The crystal structure is consolidated by intermolecular hydrogen bonds involving the 1,4,8,11-tetramethyl-1,4,8,11-tetraazoniacyclotetradecane N—H and C—H groups as donor groups, and the O atoms of the perchlorate and chloride anion as acceptor groups, giving rise to a three-dimensional network. Full Article text
rc Syntheses and crystal structures of a new pyrazine dicarboxamide ligand, N2,N3-bis(quinolin-8-yl)pyrazine-2,3-dicarboxamide, and of a copper perchlorate binuclear complex By scripts.iucr.org Published On :: 2020-02-14 The title pyrazine dicarboxamide ligand, N2,N3-bis(quinolin-8-yl)pyrazine-2,3-dicarboxamide (H2L1), C24H16N6O2, has a twisted conformation with the outer quinoline groups being inclined to the central pyrazine ring by 9.00 (6) and 78.67 (5)°, and by 79.94 (4)° to each other. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming layers parallel to the (10overline{1}) plane, which are in turn linked by offset π–π interactions [intercentroid distances 3.4779 (9) and 3.6526 (8) Å], forming a supramolecular three-dimensional structure. Reaction of the ligand H2L1 with Cu(ClO4)2 in acetonitrile leads to the formation of the binuclear complex, [μ-(3-{hydroxy[(quinolin-8-yl)imino]methyl}pyrazin-2-yl)[(quinolin-8-yl)imino]methanolato]bis[diacetonitrilecopper(II)] tris(perchlorate) acetonitrile disolvate, [Cu2(C24H15N6O2)(CH3CN)4](ClO4)3·2CH3CN or [Cu2(HL1−)(CH3CN)4](ClO4)3·2CH3CN (I). In the cation of complex I, the ligand coordinates to the copper(II) atoms in a bis-tridentate fashion. A resonance-assisted O—H⋯O hydrogen bond is present in the ligand; the position of this H atom was located in a difference-Fourier map. Both copper(II) atoms are fivefold coordinate, being ligated by three N atoms of the ligand and by the N atoms of two acetonitrile molecules. The first copper atom has a perfect square-pyramidal geometry while the second copper atom has a distorted shape. In the crystal, the cation and perchlorate anions are linked by a number of C—H⋯O hydrogen bonds, forming a supramolecular three-dimensional structure. Full Article text
rc Structural investigation of methyl 3-(4-fluorobenzoyl)-7-methyl-2-phenylindolizine-1-carboxylate, an inhibitory drug towards Mycobacterium tuberculosis By scripts.iucr.org Published On :: 2020-03-20 The title compound, C24H18FNO3, crystallizes in the monoclinic centrosymmetric space group P21/n and its molecular conformation is stabilized via C—H⋯O intramolecular interactions. The supramolecular network mainly comprises C—H⋯O, C—H⋯F and C—H⋯π interactions, which contribute towards the formation of the crystal structure. The different intermolecular interactions have been further analysed via Hirshfeld surface analysis and fingerprint plots. Full Article text
rc Extraordinary structural complexity of ilmajokite: a multilevel hierarchical framework structure of natural origin By scripts.iucr.org Published On :: 2020-01-01 The crystal structure of ilmajokite, a rare Na-K-Ba-Ce-titanosilicate from the Khibiny mountains, Kola peninsula, Russia, has been solved using single-crystal X-ray diffraction data. The crystal structure is based on a 3D titanosilicate framework consisting of trigonal prismatic titanosilicate (TPTS) clusters centered by Ce3+ in [9]-coordination. Four adjacent TPTS clusters are linked into four-membered rings within the (010) plane and connected via ribbons parallel to 101. The ribbons are organized into layers parallel to (010) and modulated along the a axis with a modulation wavelength of csinβ = 32.91 Å and an amplitude of ∼b/2 = 13.89 Å. The layers are linked by additional silicate tetrahedra. Na+, K+, Ba2+ and H2O groups occur in the framework cavities and have different occupancies and coordination environments. The crystal structure of ilmajokite can be separated into eight hierarchical levels: atoms, coordination polyhedra, TPTS clusters, rings, ribbons, layers, the framework and the whole structure. The information-based analysis allows estimation of the complexity of the structure as 8.468 bits per atom and 11990.129 bits per cell. According to this analysis, ilmajokite is the third-most complex mineral known to date after ewingite and morrisonite, and is the most complex mineral framework structure, comparable in complexity to paulingite-(Ca) (11 590.532 bits per cell). Full Article text
rc Evidence for binary Smc complexes lacking kite subunits in archaea By scripts.iucr.org Published On :: 2020-01-16 SMC complexes play a central role in chromosome organization in all domains of life. The bacterial Smc–ScpAB complex is a three-subunit complex composed of Smc, ScpA and ScpB. ScpA bridges the two ATPase domains of the Smc homodimer, while ScpB, which belongs to the kite family of proteins, interacts with ScpA. The three subunits are known to be equally important for the function of Smc–ScpAB in bacteria. From crystallographic and biochemical studies, evidence is provided that six archaeal ScpA proteins are unable to interact with the only putative ScpB found in these species. Structure-based sequence alignment reveals that these archaeal ScpAs lack the ScpB-binding segment that is commonly present in the middle of bacterial ScpA sequences, which is thus responsible for their inability to interact with ScpB. ScpA proteins lacking the ScpB-binding segment are found to prevail in archaea. Moreover, two archaeal ScpA proteins with a longer middle region also failed to bind their putative ScpB partner. Furthermore, all or most species belonging to five out of 14 euryarchaeotal orders contain Smc and ScpA but not a detectable ScpB homologue. These data support the notion that archaeal Smc-based complexes generally function as a two-subunit complex composed of only Smc and ScpA. Full Article text
rc Plasmodium vivax and human hexokinases share similar active sites but display distinct quaternary architectures By scripts.iucr.org Published On :: 2020-03-26 Malaria is a devastating disease caused by a protozoan parasite. It affects over 300 million individuals and results in over 400 000 deaths annually, most of whom are young children under the age of five. Hexokinase, the first enzyme in glucose metabolism, plays an important role in the infection process and represents a promising target for therapeutic intervention. Here, cryo-EM structures of two conformational states of Plasmodium vivax hexokinase (PvHK) are reported at resolutions of ∼3 Å. It is shown that unlike other known hexokinase structures, PvHK displays a unique tetrameric organization (∼220 kDa) that can exist in either open or closed quaternary conformational states. Despite the resemblance of the active site of PvHK to its mammalian counterparts, this tetrameric organization is distinct from that of human hexokinases, providing a foundation for the structure-guided design of parasite-selective antimalarial drugs. Full Article text
rc Supercell refinement: a cautionary tale By scripts.iucr.org Published On :: 2019-08-28 Theoretically, crystals with supercells exist at a unique crossroads where they can be considered as either a large unit cell with closely spaced reflections in reciprocal space or a higher dimensional superspace with a modulation that is commensurate with the supercell. In the latter case, the structure would be defined as an average structure with functions representing a modulation to determine the atomic location in 3D space. Here, a model protein structure and simulated diffraction data were used to investigate the possibility of solving a real incommensurately modulated protein crystal using a supercell approximation. In this way, the answer was known and the refinement method could be tested. Firstly, an average structure was solved by using the `main' reflections, which represent the subset of the reflections that belong to the subcell and in general are more intense than the `satellite' reflections. The average structure was then expanded to create a supercell and refined using all of the reflections. Surprisingly, the refined solution did not match the expected solution, even though the statistics were excellent. Interestingly, the corresponding superspace group had multiple 3D daughter supercell space groups as possibilities, and it was one of the alternate daughter space groups that the refinement locked in on. The lessons learned here will be applied to a real incommensurately modulated profilin–actin crystal that has the same superspace group. Full Article text
rc Improved chemistry restraints for crystallographic refinement by integrating the Amber force field into Phenix By scripts.iucr.org Published On :: 2020-01-01 The refinement of biomolecular crystallographic models relies on geometric restraints to help to address the paucity of experimental data typical in these experiments. Limitations in these restraints can degrade the quality of the resulting atomic models. Here, an integration of the full all-atom Amber molecular-dynamics force field into Phenix crystallographic refinement is presented, which enables more complete modeling of biomolecular chemistry. The advantages of the force field include a carefully derived set of torsion-angle potentials, an extensive and flexible set of atom types, Lennard–Jones treatment of nonbonded interactions and a full treatment of crystalline electrostatics. The new combined method was tested against conventional geometry restraints for over 22 000 protein structures. Structures refined with the new method show substantially improved model quality. On average, Ramachandran and rotamer scores are somewhat better, clashscores and MolProbity scores are significantly improved, and the modeling of electrostatics leads to structures that exhibit more, and more correct, hydrogen bonds than those refined using traditional geometry restraints. In general it is found that model improvements are greatest at lower resolutions, prompting plans to add the Amber target function to real-space refinement for use in electron cryo-microscopy. This work opens the door to the future development of more advanced applications such as Amber-based ensemble refinement, quantum-mechanical representation of active sites and improved geometric restraints for simulated annealing. Full Article text
rc The crystal structure of the heme d1 biosynthesis-associated small c-type cytochrome NirC reveals mixed oligomeric states in crystallo By scripts.iucr.org Published On :: 2020-03-25 Monoheme c-type cytochromes are important electron transporters in all domains of life. They possess a common fold hallmarked by three α-helices that surround a covalently attached heme. An intriguing feature of many monoheme c-type cytochromes is their capacity to form oligomers by exchanging at least one of their α-helices, which is often referred to as 3D domain swapping. Here, the crystal structure of NirC, a c-type cytochrome co-encoded with other proteins involved in nitrite reduction by the opportunistic pathogen Pseudomonas aeruginosa, has been determined. The crystals diffracted anisotropically to a maximum resolution of 2.12 Å (spherical resolution of 2.83 Å) and initial phases were obtained by Fe-SAD phasing, revealing the presence of 11 NirC chains in the asymmetric unit. Surprisingly, these protomers arrange into one monomer and two different types of 3D domain-swapped dimers, one of which shows pronounced asymmetry. While the simultaneous observation of monomers and dimers probably reflects the interplay between the high protein concentration required for crystallization and the structural plasticity of monoheme c-type cytochromes, the identification of conserved structural motifs in the monomer together with a comparison with similar proteins may offer new leads to unravel the unknown function of NirC. Full Article text
rc High-energy-resolution inelastic X-ray scattering spectrometer at beamline 30-ID of the Advanced Photon Source By scripts.iucr.org Published On :: 2020-04-06 Inelastic X-ray scattering is a powerful and versatile technique for studying lattice dynamics in materials of scientific and technological importance. In this article, the design and capabilities of the momentum-resolved high-energy-resolution inelastic X-ray spectrometer (HERIX) at beamline 30-ID of the Advanced Photon Source are reported. The instrument operates at 23.724 keV and has an energy resolution of 1.3–1.7 meV. It can accommodate momentum transfers of up to 72 nm−1, at a typical X-ray flux of 4.5 × 109 photons s−1 meV−1 at the sample. A suite of in situ sample environments are provided, including high pressure, static magnetic fields and uniaxial strains, all at high or cryogenic temperatures. Full Article text
rc Linearly polarized X-ray fluorescence computed tomography based on a Thomson scattering light source: a Monte Carlo study By scripts.iucr.org Published On :: 2020-04-06 A Thomson scattering X-ray source can provide quasi-monochromatic, continuously energy-tunable, polarization-controllable and high-brightness X-rays, which makes it an excellent tool for X-ray fluorescence computed tomography (XFCT). In this paper, we examined the suppression of Compton scattering background in XFCT using the linearly polarized X-rays and the implementation feasibility of linearly polarized XFCT based on this type of light source, concerning the influence of phantom attenuation and the sampling strategy, its advantage over K-edge subtraction computed tomography (CT), the imaging time, and the potential pulse pile-up effect by Monte Carlo simulations. A fan beam and pinhole collimator geometry were adopted in the simulation and the phantom was a polymethyl methacrylate cylinder inside which were gadolinium (Gd)-loaded water solutions with Gd concentrations ranging from 0.2 to 4.0 wt%. Compared with the case of vertical polarization, Compton scattering was suppressed by about 1.6 times using horizontal polarization. An accurate image of the Gd-containing phantom was successfully reconstructed with both spatial and quantitative identification, and good linearity between the reconstructed value and the Gd concentration was verified. When the attenuation effect cannot be neglected, one full cycle (360°) sampling and the attenuation correction became necessary. Compared with the results of K-edge subtraction CT, the contrast-to-noise ratio values of XFCT were improved by 2.03 and 1.04 times at low Gd concentrations of 0.2 and 0.5 wt%, respectively. When the flux of a Thomson scattering light source reaches 1013 photons s−1, it is possible to finish the data acquisition of XFCT at the minute or second level without introducing pulse pile-up effects. Full Article text
rc A high-power, high-repetition-rate THz source for pump–probe experiments at Linac Coherent Light Source II By journals.iucr.org Published On :: Full Article text
rc POWGEN: rebuild of a third-generation powder diffractometer at the Spallation Neutron Source By scripts.iucr.org Published On :: 2019-10-01 The neutron powder diffractometer POWGEN at the Spallation Neutron Source has recently (2017–2018) undergone an upgrade which resulted in an increased detector complement along with a full overhaul of the structural design of the instrument. The current instrument has a solid angular coverage of 1.2 steradians and maintains the original third-generation concept, providing a single-histogram data set over a wide d-spacing range and high resolution to access large unit cells, detailed structural refinements and in situ/operando measurements. Full Article text
rc Mercury 4.0: from visualization to analysis, design and prediction By scripts.iucr.org Published On :: 2020-02-01 The program Mercury, developed at the Cambridge Crystallographic Data Centre, was originally designed primarily as a crystal structure visualization tool. Over the years the fields and scientific communities of chemical crystallography and crystal engineering have developed to require more advanced structural analysis software. Mercury has evolved alongside these scientific communities and is now a powerful analysis, design and prediction platform which goes a lot further than simple structure visualization. Full Article text
rc In-house texture measurement using a compact neutron source By scripts.iucr.org Published On :: 2020-03-25 In order to improve the instrumental accessibility of neutron diffraction techniques, many emerging compact neutron sources and in-house neutron diffractometers are being developed, even though the precision level of neutron diffraction experiments performed on such instruments was thought to be incomparable with that of large-scale neutron facilities. As a challenging project, the RIKEN accelerator-driven compact neutron source (RANS) was employed here to establish the technical environment for texture measurements, and the recalculated pole figures and orientation distribution functions of an interstitial-free steel sheet obtained from RANS were compared with the results from another two neutron diffractometers well established for texture measurement. These quantitative comparisons revealed that the precise neutron diffraction texture measurement at RANS has been realized successfully, and the fine region division of the neutron detector panel is invaluable for improving the stereographic resolution of texture measurements. Moreover, through selectively using the parts of the obtained neutron diffraction patterns that exhibit good statistics, the Rietveld texture analysis improves the reliability of the texture measurement to a certain extent. These technical research results may accelerate the development of other easily accessible techniques for evaluation of engineering materials using compact neutron sources, and also help to improve the data-collection efficiency for various time-resolved scattering experiments at large-scale neutron facilities. Full Article text
rc AMi: a GUI-based, open-source system for imaging samples in multi-well plates By scripts.iucr.org Published On :: 2019-08-06 Described here are instructions for building and using an inexpensive automated microscope (AMi) that has been specifically designed for viewing and imaging the contents of multi-well plates. The X, Y, Z translation stage is controlled through dedicated software (AMiGUI) that is being made freely available. Movements are controlled by an Arduino-based board running grbl, and the graphical user interface and image acquisition are controlled via a Raspberry Pi microcomputer running Python. Images can be written to the Raspberry Pi or to a remote disk. Plates with multiple sample wells at each row/column position are supported, and a script file for automated z-stack depth-of-field enhancement is written along with the images. The graphical user interface and real-time imaging also make it easy to manually inspect and capture images of individual samples. Full Article text
rc Structure of the archaeal chemotaxis protein CheY in a domain-swapped dimeric conformation By scripts.iucr.org Published On :: 2019-08-30 Archaea are motile by the rotation of the archaellum. The archaellum switches between clockwise and counterclockwise rotation, and movement along a chemical gradient is possible by modulation of the switching frequency. This modulation involves the response regulator CheY and the archaellum adaptor protein CheF. In this study, two new crystal forms and protein structures of CheY are reported. In both crystal forms, CheY is arranged in a domain-swapped conformation. CheF, the protein bridging the chemotaxis signal transduction system and the motility apparatus, was recombinantly expressed, purified and subjected to X-ray data collection. Full Article text
rc Rv0100, a proposed acyl carrier protein in Mycobacterium tuberculosis: expression, purification and crystallization. Corrigendum By scripts.iucr.org Published On :: 2020-04-02 The true identity of the protein found in the crystals reported by Bondoc et al. [(2019), Acta Cryst. F75, 646–651] is given. Full Article text
rc New research reveals our galaxy is much larger than we thought By insider.si.edu Published On :: Mon, 06 Jul 2009 17:50:22 +0000 New measurements show that the Milky Way is bigger and more massive than previous data suggested, putting us on equal footing with our neighbor. Specifically, the Milky Way is 15 percent larger in size and contains 50 percent more mass. That is the cosmic equivalent of a 5-foot-5, 140-pound man suddenly bulking up to the size of a 6-foot-3, 210-pound NFL linebacker. The post New research reveals our galaxy is much larger than we thought appeared first on Smithsonian Insider. Full Article Research News Science & Nature Space astronomy astrophysics galaxies Milky Way Smithsonian Astrophysical Observatory
rc Research collection of pollen grains given to Smithsonian Tropical Research Institute By insider.si.edu Published On :: Mon, 06 Jul 2009 15:42:58 +0000 The Smithsonian Tropical Research Institute in Panama was recently given a collection of more than 25,000 different pollen grains and spores, each mounted on a microscope slide and labeled according to the plant that produced it. “The collection is worldwide in coverage with an emphasis on plants of the Americas,” explains collection donor Alan Graham, professor emeritus at Kent State University and curator at the Missouri Botanical Garden. The post Research collection of pollen grains given to Smithsonian Tropical Research Institute appeared first on Smithsonian Insider. Full Article Dinosaurs & Fossils Research News Science & Nature biodiversity conservation biology new acquisitions Tropical Research Institute
rc Baby Boom of Endangered Species at Smithsonian’s National Zoo’s Conservation and Research Center By insider.si.edu Published On :: Wed, 15 Jul 2009 11:49:43 +0000 It was an exciting and busy 24 hours at the National Zoo’s Conservation and Research Center in Front Royal, Va., last week as three births took place just hours apart. On the evening of July 9, a clouded leopard cub was born, followed by a Przewalski’s horse foal and a red panda cub. The post Baby Boom of Endangered Species at Smithsonian’s National Zoo’s Conservation and Research Center appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature animal births captive breeding conservation biology endangered species Smithsonian's National Zoo
rc Hall of Human Origins to open at Smithsonian’s Natural History Museum, March 17, 2010 By insider.si.edu Published On :: Mon, 19 Oct 2009 15:42:06 +0000 A major new exhibition hall dedicated to the discovery and understanding of human origins will open next year at the Smithsonian's National Museum of Natural History: The David H. Koch Hall of Human Origins The post Hall of Human Origins to open at Smithsonian’s Natural History Museum, March 17, 2010 appeared first on Smithsonian Insider. Full Article Anthropology Research News Science & Nature exhibitions extinction National Museum of Natural History
rc Telescope array finds new evidence that exploding stars are sources of cosmic rays By insider.si.edu Published On :: Tue, 10 Nov 2009 19:01:16 +0000 Nearly 100 years ago, scientists detected the first signs of cosmic rays—subatomic particles (mostly protons) that zip through space at nearly the speed of light. […] The post Telescope array finds new evidence that exploding stars are sources of cosmic rays appeared first on Smithsonian Insider. Full Article Research News Science & Nature Space astronomy astrophysics Smithsonian Astrophysical Observatory supernova
rc Researchers discover treefrog embryos can evaluate different features of vibrations By insider.si.edu Published On :: Wed, 16 Dec 2009 16:16:58 +0000 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. Full Article Research News Science & Nature amphibian frogs Tropical Research Institute
rc Fungi still visible in wood charcoal centuries after burning By insider.si.edu Published On :: Sun, 14 Mar 2010 00:23:05 +0000 Scientists from the Smithsonian Museum Conservation Institute, the University of Valencia in Spain and the University of Minnesota, recently made an important observation regarding charcoals […] The post Fungi still visible in wood charcoal centuries after burning appeared first on Smithsonian Insider. Full Article Research News Science & Nature archaeology fungi materials science Museum Conservation Institute
rc Patience and research may bring lion cubs to the National Zoo By insider.si.edu Published On :: Tue, 23 Mar 2010 17:00:35 +0000 The research and patience has paid off. The sisters, Nababiep and Shera, have spent short periods of time with the male, Luke, individually and simultaneously. This happened only after they each had spent more than a year sniffing Luke through a mesh door (called a “howdy door”). The post Patience and research may bring lion cubs to the National Zoo appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature captive breeding conservation mammals Smithsonian's National Zoo
rc New Hall of Human Origins points to environmental change as major force in evolution of hominins By insider.si.edu Published On :: Mon, 29 Mar 2010 14:31:29 +0000 Based on decades of cutting-edge research, the 15,000-square-foot Hall of Human Origins offers visitors an immersive, interactive journey through 6 million years of human evolution spelling out how defining characteristics of the human species have evolved during millions of years in response to a changing world. The post New Hall of Human Origins points to environmental change as major force in evolution of hominins appeared first on Smithsonian Insider. Full Article Anthropology Research News Science & Nature evolution exhibitions extinction National Museum of Natural History
rc NSRC to receive $25 million Investing in Innovation grant from U.S. Department of Education By insider.si.edu Published On :: Mon, 16 Aug 2010 13:34:52 +0000 The funding will allow the National Science Resources Center to validate its LASER (Leadership Assistance for Science Education Reform) Model. LASER, a systemic approach to reform, is a set of processes and strategies designed to help state, district and school leadership teams effectively implement and sustain high-quality science education for elementary, middle and secondary school students. The post NSRC to receive $25 million Investing in Innovation grant from U.S. Department of Education appeared first on Smithsonian Insider. Full Article Research News Science & Nature materials science science education
rc Scientists issue call to action for archaeological sites threatened by rising seas, urban development By insider.si.edu Published On :: Fri, 22 Oct 2010 08:41:25 +0000 Should global warming cause sea levels to rise as predicted in coming decades, thousands of archaeological sites in coastal areas around the world will be lost to erosion. With no hope of saving all of these sites, three archaeologists—Leslie Reeder of Southern Methodist University, Jon Erlandson of the University of Oregon and Torben Rick from the Smithsonian's National Museum of Natural History—have issued a call to action for scientists to assess the sites most at risk around the world. The post Scientists issue call to action for archaeological sites threatened by rising seas, urban development appeared first on Smithsonian Insider. Full Article Anthropology Marine Science Research News Science & Nature archaeology climate change National Museum of Natural History
rc Deep-sea dragonfish research By insider.si.edu Published On :: Mon, 08 Nov 2010 15:06:59 +0000 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. Full Article Animals Marine Science Research News Science & Nature Spotlight biodiversity fishes National Museum of Natural History
rc Environmental Research Center to help with Chesapeake Bay seagrass restoration By insider.si.edu Published On :: Wed, 22 Dec 2010 15:33:41 +0000 A research team from The Smithsonian Environmental Research Center and Virginia's Old Dominion University will be awarded $110,999 to develop a tool to help seagrass restorers predict which places will be the best for planting seagrasses, the Virginia Sea Grant has announced. The post Environmental Research Center to help with Chesapeake Bay seagrass restoration appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature biodiversity Chesapeake Bay climate change conservation biology Smithsonian Environmental Research Center
rc New online video series to feature Tropical Research Institute scientists By insider.si.edu Published On :: Thu, 13 Jan 2011 17:03:31 +0000 Smithsonian Tropical Research Institute community ecologist Sunshine Van Bael primarily examines the relationship between leaf cutter ants–the world’s first farmers–and the fungi that they cultivate. The post New online video series to feature Tropical Research Institute scientists appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature fungi
rc New online video series to feature Tropical Research Institute scientists By insider.si.edu Published On :: Tue, 18 Jan 2011 14:02:10 +0000 Office of Public Affairs videographers Johnny Gibbons and Brian Ireley recently headed down to the Punta Culebra Nature Center on the edge of Panama City […] The post New online video series to feature Tropical Research Institute scientists appeared first on Smithsonian Insider. Full Article Research News Science & Nature biodiversity invasive species Tropical Research Institute
rc Whale sharks featured in award-winning documentary following the work of Tropical Research Institute’s Héctor Guzman By insider.si.edu Published On :: Thu, 17 Feb 2011 19:10:06 +0000 The awarded film features STRI marine biologist Héctor M. Guzman diving with a group of five whale sharks while traveling in the Tropical Eastern Pacific. In the video, Guzmán tags a radiotransmitter to one of the sharks in order to follow its voyages. The post Whale sharks featured in award-winning documentary following the work of Tropical Research Institute’s Héctor Guzman appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature conservation conservation biology endangered species Tropical Research Institute
rc Tiny creatures collected 100 years ago confirm accelerating carbon uptake in Antarctic Ocean By insider.si.edu Published On :: Thu, 03 Mar 2011 15:16:46 +0000 Tiny Antarctic marine creatures collected 100 years ago by British Royal Navy explorer Robert Falcon Scott are giving scientists new clues about polar environmental change. The post Tiny creatures collected 100 years ago confirm accelerating carbon uptake in Antarctic Ocean appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature carbon dioxide climate change conservation biology National Museum of Natural History
rc New archaeological evidence reveals California’s Channel Islands as North America’s earliest seafaring economy By insider.si.edu Published On :: Thu, 03 Mar 2011 20:33:32 +0000 Evidence for a diversified sea-based economy among North American inhabitants dating from 12,200 to 11,400 years ago is emerging from three sites on California's Channel Islands. The post New archaeological evidence reveals California’s Channel Islands as North America’s earliest seafaring economy appeared first on Smithsonian Insider. Full Article Anthropology Dinosaurs & Fossils Marine Science Research News Science & Nature archaeology migratory birds National Museum of Natural History
rc Smithsonian researchers help block ship-borne bioinvaders with new screening strategy By insider.si.edu Published On :: Tue, 29 Mar 2011 18:52:47 +0000 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. Full Article Animals Marine Science Research News Science & Nature Chesapeake Bay conservation biology endangered species Smithsonian Environmental Research Center