alt Bis(1-dodecyl-4-aza-1-azoniabicyclo[2.2.2]octane)tetraisothiocyanatocobalt(II) By scripts.iucr.org Published On :: 2020-01-28 The title compound, [Co(C18H37N2)2(NCS)4], consists of a cobalt(II) ion positioned on the origin of the triclinic unit cell. It is coordinated by the N atoms of two trans-oriented 1-dodecyl-4-aza-1-azoniabicyclo[2.2.2]octane (DABCO+) cations, which carry n-dodecyl chains at the non-coordinating N atoms. The distorted octahedral coordination environment of the CoII ion is completed through four N atoms of isothiocyanate ions, which are arranged within the equatorial plane. Non-classical hydrogen bonding of the types C—H⋯N and C—H⋯S between the filamentous molecules lead to the formation of layers parallel to (001). Full Article text
alt 5-MeO-DALT: the freebase of N,N-diallyl-5-methoxytryptamine By scripts.iucr.org Published On :: 2020-04-17 The title compound {systematic name: N-[2-(5-methoxy-1H-indol-3-yl)ethyl]-N-(prop-2-en-1-yl)prop-2-en-1-amine), C17H22N2O, has a single tryptamine molecule in the asymmetric unit. The molecules are linked by strong N—H⋯N hydrogen bonds into zigzag chains with graph-set notation C(7) along the [010] direction. Full Article text
alt Bis(4-acetoxy-N,N-dimethyltryptammonium) fumarate: a new crystalline form of psilacetin, an alternative to psilocybin as a psilocin prodrug By scripts.iucr.org Published On :: 2019-05-31 The title compound (systematic name: bis{2-[4-(acetyloxy)-1H-indol-3-yl]ethan-1-aminium} but-2-enedioate), 2C14H19N2O2+·C4H2O42−, has a single protonated psilacetin cation and one half of a fumarate dianion in the asymmetric unit. There are N—H⋯O hydrogen bonds between the ammonium H atoms and the fumarate O atoms, as well as N—H⋯O hydrogen bonds between the indole H atoms and the fumarate O atoms. The hydrogen bonds hold the ions together in infinite one-dimensional chains along [111]. Full Article text
alt Structure and Hirshfeld surface analysis of the salt N,N,N-trimethyl-1-(4-vinylphenyl)methanaminium 4-vinylbenzenesulfonate By scripts.iucr.org Published On :: 2019-06-04 In the title compound, the asymmetric unit comprises an N,N,N-trimethyl-1-(4-vinylphenyl)methanaminium cation and a 4-vinylbenzenesulfonate anion, C12H18N+·C8H7O3S−. The salt has a polymerizable vinyl group attached to both the cation and the anion. The methanaminium and vinyl substituents on the benzene ring of the cation subtend angles of 86.6 (3) and 10.5 (9)° to the ring plane, while the anion is planar excluding the sulfonate O atoms. The vinyl substituent on the benzene ring of the cation is disordered over two sites with a refined occupancy ratio of 0.542 (11):0.458 (11). In the crystal, C—H⋯O hydrogen bonds dominate the packing and combine with a C—H⋯π(ring) contact to stack the cations and anions along the a-axis direction. Hirshfeld surface analysis of the salt and of the individual cation and anion components is also reported. Full Article text
alt An unexpected rhenium(IV)–rhenium(VII) salt: [Co(NH3)6]3[ReVIIO4][ReIVF6]4·6H2O By scripts.iucr.org Published On :: 2019-07-12 The title hydrated salt, tris[hexaamminecobalt(III)] tetraoxidorhenate(VII) tetrakis[hexafluoridorhenate(IV)] hexahydrate, arose unexpectedly due to possible contamination of the K2ReF6 starting material with KReO4. It consists of octahedral [Co(NH3)6]3+ cation (Co1 site symmetry 1), tetrahedral [ReVIIO4]− anions (Re site symmetry 1) and octahedral [ReIVF6]2− anions (Re site symmetries 1and overline{3}). The [ReF6]2− octahedral anions (mean Re—F = 1.834 Å), [Co(NH3)6]3+ octahedral cations (mean Co—N = 1.962 Å), and the [ReO4]− tetrahedral anion (mean Re—O = 1.719 Å) are slightly distorted. A network of N—H⋯F hydrogen bonds consolidates the structure. The crystal studied was refined as a two-component twin. Full Article text
alt Crystal structures of an imidazo[1,5-a]pyridinium-based ligand and its (C13H12N3)2[CdI4] hybrid salt By scripts.iucr.org Published On :: 2019-07-19 The monocation product of the oxidative condensation–cyclization between two molecules of pyridine-2-carbaldehyde and one molecule of CH3NH2·HCl in methanol, 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium, was isolated in the presence of metal ions as bis[2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridin-2-ium] tetraiodocadmate, (C13H12N3)2[CdI4], (I), and the mixed chloride/nitrate salt, bis[2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridin-2-ium] 1.5-chloride 0.5-nitrate trihydrate, 2C13H12N3+·1.5Cl−·0.5NO3−·3H2O, (II). Hybrid salt (I) crystallizes in the space group P21/n with two [L]2[CdI4] molecules in the asymmetric unit related by pseudosymmetry. In the crystal of (I), layers of organic cations and of tetrahalometallate anions are stacked parallel to the ab plane. Antiparallel L+ cations disposed in a herring-bone pattern form π-bonded chains through aromatic stacking. In the inorganic layer, adjacent tetrahedral CdI4 units have no connectivity but demonstrate close packing of iodide anions. In the crystal lattice of (II), the cations are arranged in stacks propagating along the a axis; the one-dimensional hydrogen-bonded polymer built of chloride ions and water molecules runs parallel to a column of stacked cations. Full Article text
alt A molybdenum tris(dithiolene) complex coordinates to three bound cobalt centers in three different ways By scripts.iucr.org Published On :: 2019-07-26 The synthesis and structural characterization of the molecular compound (μ3-benzene-1,2-dithiolato)hexacarbonylbis(μ3-1,1,1,4,4,4-hexafluorobut-2-ene-2,3-dithiolato)tricobaltmolybdenum, [Co3Mo(C4F6S2)2(C6H4S2)(CO)6] or Mo(tfd)2(bdt)(Co(CO)2)3 (tfd is 1,1,1,4,4,4-hexafluorobut-2-ene-2,3-dithiolate and bdt is benzene-1,2-dithiolate), are reported. The structure of the molecule contains the molybdenum tris(dithiolene) complex Mo(tfd)2(bdt) coordinated as a multidentate ligand to three cobalt dicarbonyl units. Each of the three cobalt centers is relatively close to molybdenum, with Co⋯Mo distances of 2.7224 (7), 2.8058 (7), and 2.6320 (6) Å. Additionally, each of the cobalt centers is bound via main-group donor atoms, but each one in a different way: the first cobalt atom is coordinated by two sulfur atoms from different dithiolenes (bdt and tfd). The second cobalt atom is coordinated by one sulfur from one tfd and two olefinic carbons from another tfd. The third cobalt is coordinated by one sulfur from bdt and two sulfurs from tfd. This is, to the best of our knowledge, the first structurally characterized example of a molybdenum (tris)dithiolene complex that coordinates to cobalt. The F atoms of two of the –CF3 groups were refined as disordered over two sets of sites with ratios of refined occupancies of 0.703 (7):0.297 (7) and 0.72 (2):0.28 (2). Full Article text
alt The fumarate salts of the N-isopropyl-N-methyl derivatives of DMT and psilocin By scripts.iucr.org Published On :: 2019-08-16 The solid-state structures of the salts of two substituted tryptamines, namely N-isopropyl-N-methyltryptaminium (MiPT) fumarate {systematic name: [2-(1H-indol-3-yl)ethyl](methyl)propan-2-ylazanium 3-carboxyprop-2-enoate}, C14H21N2+·C4H3O4−, and 4-hydroxy-N-isopropyl-N-methyltryptaminium (4-HO-MiPT) fumarate monohydrate {systematic name: [2-(4-hydroxy-1H-indol-3-yl)ethyl](methyl)propan-2-ylazanium 3-carboxyprop-2-enoate monohydrate}, C14H21N2O+·C4H3O4−·H2O, are reported. Both salts possess a protonated tryptammonium cation and a 3-carboxyacrylate (hydrogen fumarate) anion in the asymmetric unit; the 4-HO-MiPT structure also contains a water molecule of crystallization. Both cations feature disorder of the side chain over two orientations, in a 0.630 (3):0.370 (3) ratio for MiPT and a 0.775 (5):0.225 (5) ratio for 4-HO-MiPT. In both extended structures, N—H⋯O and O—H⋯O hydrogen bonds generate infinite two-dimensional networks. Full Article text
alt The structure and Hirshfeld surface analysis of the salt 3-methacrylamido-N,N,N-trimethylpropan-1-aminium 2-acrylamido-2-methylpropane-1-sulfonate By scripts.iucr.org Published On :: 2019-09-10 The title salt, C10H21N2O+·C7H12NO4S−, comprises a 3-methacrylamido-N,N,N-trimethylpropan-1-aminium cation and a 2-acrylamido-2-methylpropane-1-sulfonate anion. The salt crystallizes with two unique cation–anion pairs in the asymmetric unit of the orthorhombic unit cell. The crystal studied was an inversion twin with a 0.52 (4):0.48 (4) domain ratio. In the crystal, the cations and anions stack along the b-axis direction and are linked by an extensive series of N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network. Hirshfeld surface analysis was carried out on both the asymmetric unit and the two individual salts. The contribution of interatomic contacts to the surfaces of the individual cations and anions are also compared. Full Article text
alt Twelve 4-(4-methoxyphenyl)piperazin-1-ium salts containing organic anions: supramolecular assembly in one, two and three dimensions By scripts.iucr.org Published On :: 2019-09-20 Twelve 4-(4-methoxyphenyl)piperazin-1-ium salts containing organic anions have been prepared and structurally characterized. The monohydrated benzoate, 4-fluorobenzoate, 4-chlorobenzoate and 4-bromobenzoate salts, C11H17N2O+·C7H5O2−·H2O (I), C11H17N2O+·C7H4FO2−·H2O (II), C11H17N2O+·C7H4ClO2−·H2O (III), and C11H17N2O+·C7H4BrO2−·H2O (IV), respectively, are isomorphous and all exhibit disorder in the 4-methoxyphenyl unit: the components are linked by N—H⋯O and O—H⋯O hydrogen bond to form chains of rings. The unsolvated 2-hydroxybenzoate, pyridine-3-carboxylate and 2-hydroxy-3,5-dinitrobenzoate salts, C11H17N2O+·C7H5O3− (V), C11H17N2O+·C6H4NO2− (VI) and C11H17N2O+·C7H3N2O7− (VII), respectively, are all fully ordered: the components of (V) are linked by multiple N—H⋯O hydrogen bonds to form a chain of rings; those of (VI) are linked into a three-dimensional framework by a combination of N—H⋯O, C—H⋯O and C—H⋯N hydrogen bonds and those of (VII), where the anion has a structure reminiscent of the picrate anion, are linked into a three-dimensional array by N—H⋯O and C—H⋯O hydrogen bonds. The hydrogensuccinate and hydrogenfumarate salts, C11H17N2O+·C4H5O4− (VIII) and C11H17N2O+·C4H3O3− (IX), respectively, are isomorphous, and both exhibit disorder in the anionic component: N—H⋯O and O—H⋯O hydrogen bonds link the ions into sheets, which are further linked by C—H⋯π(arene) interactions. The anion of the hydrogenmaleate salt, C11H17N2O+·C4H3O3− (X), contains a very short and nearly symmetrical O⋯H⋯O hydrogen bond, and N—H⋯O hydrogen bonds link the anions into chains of rings. The ions in the trichloroacetate salt, C11H17N2O+·C2Cl3O2− (XI), are linked into simple chains by N—H⋯O hydrogen bonds. In the hydrated chloranilate salt, 2C11H17N2O+·C6Cl2O42−·2H2O (XII), which crystallizes as a non-merohedral twin, the anion lies across a centre of inversion in space group P21/n, and a combination of N—H⋯O and O—H⋯O hydrogen bonds generates complex sheets. Comparisons are made with the structures of some related compounds. Full Article text
alt Crystal structures and hydrogen-bonding analysis of a series of solvated ammonium salts of molybdenum(II) chloride clusters By scripts.iucr.org Published On :: 2019-10-22 Charge-assisted hydrogen bonding plays a significant role in the crystal structures of solvates of ionic compounds, especially when the cation or cations are primary ammonium salts. We report the crystal structures of four ammonium salts of molybdenum halide cluster solvates where we observe significant hydrogen bonding between the solvent molecules and cations. The crystal structures of bis(anilinium) octa-μ3-chlorido-hexachlorido-octahedro-hexamolybdate N,N-dimethylformamide tetrasolvate, (C6H8N)2[Mo6Cl8Cl6]·4C3H7NO, (I), p-phenylenediammonium octa-μ3-chlorido-hexachlorido-octahedro-hexamolybdate N,N-dimethylformamide hexasolvate, (C6H10N2)[Mo6Cl8Cl6]·6C3H7NO, (II), N,N'-(1,4-phenylene)bis(propan-2-iminium) octa-μ3-chlorido-hexachlorido-octahedro-hexamolybdate acetone trisolvate, (C12H18N2)[Mo6Cl8Cl6]·3C3H6O, (III), and 1,1'-dimethyl-4,4'-bipyridinium octa-μ3-chlorido-hexachlorido-octahedro-hexamolybdate N,N-dimethylformamide tetrasolvate, (C12H14N2)[Mo6Cl8Cl6]·4C3H7NO, (IV), are reported and described. In (I), the anilinium cations and N,N-dimethylformamide (DMF) solvent molecules form a cyclic R42(8) hydrogen-bonded motif centered on a crystallographic inversion center with an additional DMF molecule forming a D(2) interaction. The p-phenylenediammonium cation in (II) forms three D(2) interactions between the three N—H bonds and three independent N,N-dimethylformamide molecules. The dication in (III) is a protonated Schiff base solvated by acetone molecules. Compound (IV) contains a methyl viologen dication with N,N-dimethylformamide molecules forming close contacts with both aromatic and methyl H atoms. Full Article text
alt Crystal structures of two coordination isomers of copper(II) 4-sulfobenzoic acid hexahydrate and two mixed silver/potassium 4-sulfobenzoic acid salts By scripts.iucr.org Published On :: 2019-10-31 A reaction of copper(II) carbonate and potassium 4-sulfobenzoic acid in water acidified with hydrochloric acid yielded two crystalline products. Tetraaquabis(4-carboxybenzenesulfonato)copper(II) dihydrate, [Cu(O3SC6H4CO2H)2(H2O)4]·2H2O, (I), crystallizes in the triclinic space group Poverline{1} with the Cu2+ ions located on centers of inversion. Each copper ion is coordinated to four water molecules in a square plane with two sulfonate O atoms in the apical positions of a Jahn–Teller-distorted octahedron. The carboxylate group is protonated and not involved in coordination to the metal ions. The complexes pack so as to create a layered structure with alternating inorganic and organic domains. The packing is reinforced by several O—H⋯O hydrogen bonds involving coordinated and non-coordinated water molecules, the carboxylic acid group and the sulfonate group. Hexaaquacopper(II) 4-carboxybenzenesulfonate, [Cu(H2O)6](O3SC6H4CO2H)2, (II), also crystallizes in the triclinic space group Poverline{1} with Jahn–Teller-distorted octahedral copper(II) aqua complexes on the centers of inversion. As in (I), the carboxylate group on the anion is protonated and the structure consists of alternating layers of inorganic cations and organic anions linked by O—H⋯O hydrogen bonds. A reaction of silver nitrate and potassium 4-sulfobenzoic acid in water also resulted in two distinct products that have been structurally characterized. An anhydrous silver potassium 4-carboxybenzenesulfonate salt, [Ag0.69K0.31](O3SC6H4CO2H), (III), crystallizes in the monoclinic space group C2/c. There are two independent metal sites, one fully occupied by silver ions and the other showing a 62% K+/38% Ag+ (fixed) ratio, refined in two slightly different positions. The coordination environments of the metal ions are composed primarily of sulfonate O atoms, with some participation by the non-protonated carboxylate O atoms in the disordered site. As in the copper compounds, the cations and anions cleanly segregate into alternating layers. A hydrated mixed silver potassium 4-carboxybenzenesulfonate salt dihydrate, [Ag0.20K0.80](O3SC6H4CO2H)·2H2O, (IV), crystallizes in the monoclinic space group P21/c with the Ag+ and K+ ions sharing one unique metal site coordinated by two water molecules and six sulfonate O atoms. The packing in (IV) follows the dominant motif of alternating inorganic and organic layers. The protonated carboxylate groups do not interact with the cations directly, but do participate in hydrogen bonds with the coordinated water molecules. (IV) is isostructural with pure potassium 4-sulfobenzoic acid dihydrate. Full Article text
alt The varied structures of cobalt(II)–pyridine (py)–sulfate: [Co(SO4)(py)4]n, [Co2(SO4)2(py)6]n, and [Co3(SO4)3(py)11]n By scripts.iucr.org Published On :: 2019-11-19 The solid-state structures of two cobalt–pyridine–sulfate compounds, namely catena-poly[[tetrakis(pyridine-κN)cobalt(II)]-μ-sulfato-κ2O:O'], [Co(SO4)(C5H5N)4]n, (1), and catena-poly[[tetrakis(pyridine-κN)cobalt(II)]-μ-sulfato-κ3O:O',O''-[bis(pyridine-κN)cobalt(II)]-μ-sulfato-κ3O,O':O'']n, [Co2(SO4)2(C5H5N)6]n, (2), are reported. Compound (1) displays a polymeric structure, with infinite chains of CoII cations adopting octahedral N4O2 coordination environments that involve four pyridine ligands and two bridging sulfate ions. Compound (2) is also polymeric with infinite chains of CoII cations. The first Co center has an octahedral N4O2 coordination environment that involves four pyridine ligands and two bridging sulfate ligands. The second Co center has an octahedral N2O4 coordination environment that involves two pyridine ligands and two bridging sulfate ions that chelate the Co atom. The structure of (2) was refined as a two-component inversion twin. Full Article text
alt Crystal structure, Hirshfeld surface analysis and computational study of bis(2-{[(2,6-dichlorobenzylidene)hydrazinylidene]methyl}phenolato)cobalt(II) and of the copper(II) analogue By scripts.iucr.org Published On :: 2020-01-01 The title homoleptic Schiff base complexes, [M(C14H9Cl2N2O)2], for M = CoII, (I), and CuII, (II), present distinct coordination geometries despite the Schiff base dianion coordinating via the phenolato-O and imine-N atoms in each case. For (I), the coordination geometry is based on a trigonal bipyramid whereas for (II), a square-planar geometry is found (Cu site symmetry overline{1}). In the crystal of (I), discernible supramolecular layers in the ac plane are sustained by chlorobenzene-C—H⋯O(coordinated), chlorobenzene-C—H⋯π(fused-benzene ring) as well as π(fused-benzene, chlorobenzene)–π(chlorobenzene) interactions [inter-centroid separations = 3.6460 (17) and 3.6580 (16) Å, respectively]. The layers inter-digitate along the b-axis direction and are linked by dichlorobenzene-C—H⋯π(fused-benzene ring) and π–π interactions between fused-benzene rings and between chlorobenzene rings [inter-centroid separations = 3.6916 (16) and 3.7968 (19) Å, respectively] . Flat, supramolecular layers are also found in the crystal of (II), being stabilized by π–π interactions formed between fused-benzene rings and between chlorobenzene rings [inter-centroid separations = 3.8889 (15) and 3.8889 (15) Å, respectively]; these stack parallel to [10overline{1}] without directional interactions between them. The analysis of the respective calculated Hirshfeld surfaces indicate diminished roles for H⋯H contacts [26.2% (I) and 30.5% (II)] owing to significant contributions by Cl⋯H/H⋯Cl contacts [25.8% (I) and 24.9% (II)]. Minor contributions by Cl⋯Cl [2.2%] and Cu⋯Cl [1.9%] contacts are indicated in the crystals of (I) and (II), respectively. The interaction energies largely arise from dispersion terms; the aforementioned Cu⋯Cl contact in (II) gives rise to the most stabilizing interaction in the crystal of (II). Full Article text
alt An unusually short intermolecular N—H⋯N hydrogen bond in crystals of the hemi-hydrochloride salt of 1-exo-acetamidopyrrolizidine By scripts.iucr.org Published On :: 2020-01-01 The title compound [systematic name: (1R*, 8S)-2-acetamidooctahydropyrrolizin-4-ium chloride–N-[(1R, 8S)-hexahydro-1H-pyrrolizin-2-yl)acetamide (1/1)], 2(C9H16N2O)·HCl or C9H17N2O+·Cl−·C9H16N2O, arose as an unexpected product when 1-exo-acetamidopyrrolizidine (AcAP; C9H16N2O) was dissolved in CHCl3. Within the AcAP pyrrolizidine group, the unsubstituted five-membered ring is disordered over two orientations in a 0.897 (5):0.103 (5) ratio. Two AcAP molecules related by a crystallographic twofold axis link to H+ and Cl− ions lying on the rotation axis, thereby forming N—H⋯N and N—H⋯Cl⋯H—N hydrogen bonds. The first of these has an unusually short N⋯N separation of 2.616 (2) Å: refinement of different models against the present data set could not distinguish between a symmetrical hydrogen bond (H atom lying on the twofold axis and equidistant from the N atoms) or static or dynamic disorder models (i.e. N—H⋯N + N⋯H—N). Computational studies suggest that the disorder model is slightly more stable, but the energy difference is very small. Full Article text
alt Crystal structure of imidazo[1,5-a]pyridinium-based hybrid salt (C13H12N3)2[MnCl4] By scripts.iucr.org Published On :: 2020-02-06 A new organic–inorganic hybrid salt [L]2[MnCl4] (I) where L+ is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, is built of discrete organic cations and tetrachloridomanganate(II) anions. The L+ cation was formed in situ in the oxidative cyclocondensation of 2-pyridinecarbaldehyde and CH3NH2·HCl in methanol. The structure was refined as a two-component twin using PLATON (Spek, 2020) to de-twin the data. The twin law (−1 0 0 0 − 1 0 0.5 0 1) was applied in the refinement where the twin component fraction refined to 0.155 (1). The compound crystallizes in the space group P21/c with two crystallographically non-equivalent cations in the asymmetric unit, which possess similar structural conformations. The fused pyridinium and imidazolium rings of the cations are virtually coplanar [dihedral angles are 0.89 (18) and 0.78 (17)°]; the pendant pyridyl rings are twisted by 36.83 (14) and 36.14 (13)° with respect to the planes of the remaining atoms of the cations. The tetrahedral MnCl42– anion is slightly distorted with the Mn—Cl distances falling in the range 2.3469 (10)–2.3941 (9) Å. The distortion value of 0.044 relative to the ideal tetrahedron was obtained by continuous shape measurement (CShM) analysis. In the crystal, the cations and anions form separate stacks propagating along the a-axis direction. The organic cations display weak π–π stacking. The anions, which are stacked identically one above the other, demonstrate loose packing; the minimum Mn⋯Mn separation in the cation stack is approximately 7.49 Å. The investigation of the fluorescent properties of a powdered sample of (I) showed no emission. X-band EPR data for (I) at 293 and 77 K revealed broad fine structure signals, indicating moderate zero-field splitting. Full Article text
alt Crystal structures of the recreational drug N-(4-methoxyphenyl)piperazine (MeOPP) and three of its salts By scripts.iucr.org Published On :: 2020-03-05 Crystal structures are reported for N-(4-methoxyphenyl)piperazine (MeOPP), (I), and for its 3,5-dinitrobenzoate, 2,4,6-trinitrophenolate (picrate) and 4-aminobenzoate salts, (II)–(IV), the last of which crystallizes as a monohydrate. In MeOPP, C11H16N2O, (I), the 4-methoxyphenyl group is nearly planar and it occupies an equatorial site on the piperazine ring: the molecules are linked into simple C(10) chains by N—H⋯O hydrogen bonds. In each of the salts, i.e., C11H17N2O+·C7H3N2O6−, (II), C11H17N2O+·C6H2N3O7−, (III), and C11H17N2O+·C7H6NO2−·H2O, (IV), the effectively planar 4-methoxyphenyl substituent again occupies an equatorial site on the piperazine ring. In (II), two of the nitro groups are disordered over two sets of atomic sites and the bond distances in the anion indicate considerable delocalization of the negative charge over the C atoms of the ring. The ions in (II) are linked by two N—H⋯O hydrogen bonds to form a cyclic, centrosymmetric four-ion aggregate; those in (III) are linked by a combination of N—H⋯O and C—H⋯π(arene) hydrogen bonds to form sheets; and the components of (IV) are linked by N—H⋯O, O—H⋯O and C—H⋯π(arene) hydrogen bonds to form a three-dimensional framework structure. Comparisons are made with the structures of some related compounds. Full Article text
alt Crystal structure and photoluminescent properties of bis(4'-chloro-2,2':6',2''-terpyridyl)cobalt(II) dichloride tetrahydrate By scripts.iucr.org Published On :: 2020-03-05 In the title hydrated complex, [Co(C15H10ClN3)2]Cl2·4H2O, the complete dication is generated by overline{4} symmetry. The CoN6 moiety shows distortion from regular octahedral geometry with the trans bond angles of two N—Co—N units being 160.62 (9)°. In the crystal, O—H⋯Cl and C—H⋯O interactions link the components into (001) sheets. The title compound exhibits blue-light emission, as indicated by photoluminescence data, and a HOMO–LUMO energy separation of 2.23 eV was obtained from its diffuse reflectance spectrum. Full Article text
alt Different packing motifs in the crystal structures of three molecular salts containing the 2-amino-5-carboxyanilinium cation: C7H9N2O2+·Cl−, C7H9N2O2+·Br− and C7H9N2O2+·NO3−·H2O By scripts.iucr.org Published On :: 2020-03-13 The syntheses and crystal structures of three molecular salts of protonated 3,4-diaminobenzoic acid, viz. 2-amino-5-carboxyanilinium chloride, C7H9N2O2+·Cl−, (I), 2-amino-5-carboxyanilinium bromide, C7H9N2O2+·Br−, (II), and 2-amino-5-carboxyanilinium nitrate monohydrate, C7H9N2O2+·NO3−·H2O, (III), are described. The cation is protonated at the meta-N atom (with respect to the carboxy group) in each case. In the crystal of (I), carboxylic acid inversion dimers linked by pairwise O—H⋯O hydrogen bonds are seen and each N—H group forms a hydrogen bond to a chloride ion to result in (100) undulating layers of chloride ions bridged by the inversion dimers into a three-dimensional network. The extended structure of (II) features O—H⋯Br, N—H⋯Br and N—H⋯O hydrogen bonds: the last of these generates C(7) chains of cations. Overall, the packing in (II) features undulating (100) sheets of bromide ions alternating with the organic cations. Intermolecular interactions in the crystal of (III) include O—H⋯O, O—H⋯(O,O), N—H⋯O, N—H⋯N and O—H⋯N links. The cations are linked into (001) sheets, and the nitrate ions and water molecules form undulating chains. Taken together, alternating (001) slabs of organic cations plus anions/water molecules result. Hirshfeld surfaces and fingerprint plots were generated to give further insight into the intermolecular interactions in these structures. The crystal used for the data collection of (II) was twinned by rotation about [100] in reciprocal space in a 0.4896 (15):0.5104 (15) ratio. Full Article text
alt Norpsilocin: freebase and fumarate salt By scripts.iucr.org Published On :: 2020-03-27 The solid-state structures of the naturally occurring psychoactive tryptamine norpsilocin {4-hydroxy-N-methyltryptamine (4-HO-NMT); systematic name: 3-[2-(methylamino)ethyl]-1H-indol-4-ol}, C11H14N2O, and its fumarate salt (4-hydroxy-N-methyltryptammonium fumarate; systematic name: bis{[2-(4-hydroxy-1H-indol-3-yl)ethyl]methylazanium} but-2-enedioate), C11H15N2O+·0.5C4H2O42−, are reported. The freebase of 4-HO-NMT has a single molecule in the asymmetric unit joined together by N—H⋯O and O—H⋯O hydrogen bonds in a two-dimensional network parallel to the (100) plane. The ethylamine arm of the tryptamine is modeled as a two-component disorder with a 0.895 (3) to 0.105 (3) occupancy ratio. The fumarate salt of 4-HO-NMT crystallizes with a tryptammonium cation and one half of a fumarate dianion in the asymmetric unit. The ions are joined together by N—H⋯O and O—H⋯O hydrogen bonds to form a three-dimensional framework, as well as π–π stacking between the six-membered rings of inversion-related indoles (symmetry operation: 2 − x, 1 − y, 2 – z). Full Article text
alt Synthesis and crystal structure of a 6-chloronicotinate salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4'-bipyridine By scripts.iucr.org Published On :: 2020-04-02 A 6-chloronicotinate (6-Clnic) salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4'-bipyridine (4,4'-bpy), namely, catena-poly[[[tetraaquanickel(II)]-μ-4,4'-bipyridine-κ2N:N'] bis(6-chloronicotinate) tetrahydrate], {[Ni(C10H8N2)(H2O)4](C6H3ClNO2)2·4H2O}n or {[Ni(4,4'-bpy)(H2O)4](6-Clnic)2·4H2O}n, (1), was prepared by the reaction of nickel(II) sulfate heptahydrate, 6-chloronicotinic acid and 4,4'-bipyridine in a mixture of water and ethanol. The molecular structure of 1 comprises a one-dimensional polymeric {[Ni(4,4'-bpy)(H2O)4]2+}n cation, two 6-chloronicotinate anions and four water molecules of crystallization per repeating polymeric unit. The nickel(II) ion in the polymeric cation is octahedrally coordinated by four water molecule O atoms and by two 4,4'-bipyridine N atoms in the trans position. The 4,4'-bipyridine ligands act as bridges and, thus, connect the symmetry-related nickel(II) ions into an infinite one-dimensional polymeric chain extending along the b-axis direction. In the extended structure of 1, the polymeric chains of {[Ni(4,4'-bpy)(H2O)4]2+}n, the 6-chloronicotinate anions and the water molecules of crystallization are assembled into an infinite three-dimensional hydrogen-bonded network via strong O—H⋯O and O—H⋯N hydrogen bonds, leading to the formation of the representative hydrogen-bonded ring motifs: tetrameric R24(8) and R44(10) loops, a dimeric R22(8) loop and a pentameric R45(16) loop. Full Article text
alt A five-coordinate cobalt bis(dithiolene)–phosphine complex [Co(pdt)2(PTA)] (pdt = phenyldithiolene; PTA = 1,3,5-triaza-7-phosphaadamantane) By scripts.iucr.org Published On :: 2020-04-24 The title compound, bis(1,2-diphenyl-2-sulfanylideneethanethiolato-κ2S,S')(1,3,5-triaza-7-phosphaadamantane-κP)cobalt(II) dichloromethane hemisolvate, [Co(pdt)2(PTA)]·0.5C2H4Cl2 or [Co(C14H10S2)2(C6H12N3P)]·0.5C2H4Cl2, contains two phenyldithiolene (pdt) ligands and a 1,3,5-triaza-7-phosphaadamantane (PTA) ligand bound to cobalt with the solvent 1,2-dichloroethane molecule located on an inversion center. The cobalt core exhibits an approximately square-pyramidal geometry with partially reduced thienyl radical monoanionic ligands. The supramolecular network is consolidated by hydrogen-bonding interactions primarily with nitrogen, sulfur and chlorine atoms, as well as parallel displaced π-stacking of the aryl rings. The UV–vis, IR, and CV data are also consistent with monoanionic dithiolene ligands and an overall CoII oxidation state. Full Article text
alt Hydrogen-bonding patterns in 2,2-bis(4-methylphenyl)hexafluoropropane pyridinium and ethylenediammonium salt crystals By scripts.iucr.org Published On :: 2020-04-24 The crystal structures of two salt crystals of 2,2-bis(4-methylphenyl)hexafluoropropane (Bmphfp) with amines, namely, dipyridinium 4,4'-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoate 4,4'-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoic acid, 2C5H6N+·C17H8F6O42−·C17H10F6O4, (1), and a monohydrated ethylenediammonium salt ethane-1,2-diaminium 4,4'-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoate monohydrate, C2H10N22+·C17H8F6O42−·H2O, (2), are reported. Compounds 1 and 2 crystallize, respectively, in space group P21/c with Z' = 2 and in space group Pbca with Z' = 1. The crystals of compound 1 contain neutral and anionic Bmphfp molecules, and form a one-dimensional hydrogen-bonded chain motif. The crystals of compound 2 contain anionic Bmphfp molecules, which form a complex three-dimensional hydrogen-bonded network with the ethylenediamine and water molecules. Full Article text
alt A routine for the determination of the microstructure of stacking-faulted nickel cobalt aluminium hydroxide precursors for lithium nickel cobalt aluminium oxide battery materials By scripts.iucr.org Published On :: 2020-02-01 The microstructures of six stacking-faulted industrially produced cobalt- and aluminium-bearing nickel layered double hydroxide (LDH) samples that are used as precursors for Li(Ni1−x−yCoxAly)O2 battery materials were investigated. Shifts from the brucite-type (AγB)□(AγB)□ stacking pattern to the CdCl2-type (AγB)□(CβA)□(BαC)□ and the CrOOH-type (BγA)□(AβC)□(CαB)□ stacking order, as well as random intercalation of water molecules and carbonate ions, were found to be the main features of the microstructures. A recursive routine for generating and averaging supercells of stacking-faulted layered substances implemented in the TOPAS software was used to calculate diffraction patterns of the LDH phases as a function of the degree of faulting and to refine them against the measured diffraction data. The microstructures of the precursor materials were described by a model containing three parameters: transition probabilities for generating CdCl2-type and CrOOH-type faults and a transition probability for the random intercalation of water/carbonate layers. Automated series of simulations and refinements were performed, in which the transition probabilities were modified incrementally and thus the microstructures optimized by a grid search. All samples were found to exhibit the same fraction of CdCl2-type and CrOOH-type stacking faults, which indicates that they have identical Ni, Co and Al contents. Different degrees of interstratification faulting were determined, which could be correlated to different heights of intercalation-water-related mass-loss steps in the thermal analyses. Full Article text
alt ACMS: a database of alternate conformations found in the atoms of main and side chains of protein structures By journals.iucr.org Published On :: An online knowledge base on the alternate conformations adopted by main-chain and side-chain atoms in protein structures solved by X-ray crystallography is described. Full Article text
alt Local orientational order in self-assembled nanoparticle films: the role of ligand composition and salt By journals.iucr.org Published On :: An X-ray cross-correlation study of the impact of ligand composition and salt content on the self-assembly of soft-shell nanoparticles is presented, indicating symmetry-selective formation of order. Full Article text
alt Structure of the Mycobacterium smegmatis α-maltose-1-phosphate synthase GlgM By scripts.iucr.org Published On :: 2020-04-03 Mycobacterium tuberculosis produces glycogen (also known as α-glucan) to help evade human immunity. This pathogen uses the GlgE pathway to generate glycogen rather than the more well known glycogen synthase GlgA pathway, which is absent in this bacterium. Thus, the building block for this glucose polymer is α-maltose-1-phosphate rather than an NDP-glucose donor. One of the routes to α-maltose-1-phosphate is now known to involve the GlgA homologue GlgM, which uses ADP-glucose as a donor and α-glucose-1-phosphate as an acceptor. To help compare GlgA (a GT5 family member) with GlgM enzymes (GT4 family members), the X-ray crystal structure of GlgM from Mycobacterium smegmatis was solved to 1.9 Å resolution. While the enzymes shared a GT-B fold and several residues responsible for binding the donor substrate, they differed in some secondary-structural details, particularly in the N-terminal domain, which would be expected to be largely responsible for their different acceptor-substrate specificities. Full Article text
alt Golden years at the Zoo: Veterinarians work to help animals live longer, stay healthy By insider.si.edu Published On :: Thu, 27 Aug 2009 11:53:04 +0000 Successes in animal health care presents many new challenges for veterinarians. Longer life spans in captivity mean zoo animals are now experiencing age-related health problems that their zoo predecessors never lived long enough to develop—like diabetes in cheetahs, arthritis in big cats and dental issues for coatis. The post Golden years at the Zoo: Veterinarians work to help animals live longer, stay healthy appeared first on Smithsonian Insider. Full Article Animals Science & Nature conservation biology Smithsonian's National Zoo veterinary medicine
alt Climate change may drastically alter Chesapeake Bay, scientists say By insider.si.edu Published On :: Tue, 24 Nov 2009 19:02:16 +0000 It is one of the largest and most productive estuaries in the world, yet dramatic changes are in store for the Chesapeake Bay in coming […] The post Climate change may drastically alter Chesapeake Bay, scientists say appeared first on Smithsonian Insider. Full Article Marine Science Research News Science & Nature Chesapeake Bay climate change conservation biology Smithsonian Environmental Research Center
alt Study reveals road salt may promote health and well-being of roadside ant colonies By insider.si.edu Published On :: Mon, 30 Aug 2010 14:37:18 +0000 To understand the effects of road salting on ants, Michael Kaspari of the Smithsonian Tropical Research Institute and the University of Oklahoma led a team that looked at how ant colonies are affected by these conditions; their research is published in a recent issue of the journal Ecological Entomology. The post Study reveals road salt may promote health and well-being of roadside ant colonies appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature ants biodiversity insects Tropical Research Institute
alt It’s no sweat for salt marsh sparrows to beat the heat if they have a larger bill By insider.si.edu Published On :: Thu, 21 Jul 2011 11:43:12 +0000 A team of scientists have found that because of this, high summer temperatures have been a strong influence in determining bill size in some birds, particularly species of sparrows that favor salt marshes. The post It’s no sweat for salt marsh sparrows to beat the heat if they have a larger bill appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature biodiversity birds conservation biology Migratory Bird Center migratory birds National Museum of Natural History
alt Q&A: National Zoo veterinarian Suzan Murray is working to halt pandemic disease in hotspots around the world By insider.si.edu Published On :: Tue, 29 Nov 2011 15:12:03 +0000 Suzan Murray, chief veterinary medical officer at the Smithsonian’s National Zoological Park, recently returned from Hanoi, where she led a team of scientists training pathologists from Laos, Cambodia and Vietnam to better sample, recognize and detect wildlife diseases in hopes of preventing emerging pandemic disease. The post Q&A: National Zoo veterinarian Suzan Murray is working to halt pandemic disease in hotspots around the world appeared first on Smithsonian Insider. Full Article Animals Q & A Science & Nature Center for Tropical Forest Science Smithsonian's National Zoo veterinary medicine
alt Rising seas, development are altering prehistoric artifacts in the Chesapeake’s tidal zone By insider.si.edu Published On :: Mon, 09 Jan 2012 13:22:36 +0000 As a coastal archaeologist and expert in prehistoric and historic settlement sites in the Chesapeake Bay region, Darrin Lowery of the Smithsonian’s National Museum of Natural History and University of Deleware, is carefully watching the effects of coastal erosion and rising sea levels on coastal archaeological sites. The post Rising seas, development are altering prehistoric artifacts in the Chesapeake’s tidal zone appeared first on Smithsonian Insider. Full Article Anthropology Dinosaurs & Fossils Marine Science Science & Nature archaeology Chesapeake Bay climate change National Museum of Natural History
alt Climate change may alter amphibian evolution By insider.si.edu Published On :: Wed, 24 Oct 2012 17:46:00 +0000 Justin Touchon, post-doctoral fellow at the Smithsonian Tropical Research Institute, discovered that climate change in Panama may be altering frogs’ course of evolution. The post Climate change may alter amphibian evolution appeared first on Smithsonian Insider. Full Article Animals Science & Nature conservation biology evolution frogs
alt “The State of the Birds” assesses health of nation’s birds By insider.si.edu Published On :: Tue, 09 Sep 2014 14:01:29 +0000 One hundred years after the extinction of the passenger pigeon, the nation’s top bird science and conservation groups have come together to publish The State […] The post “The State of the Birds” assesses health of nation’s birds appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature birds Caribbean climate change Colombia conservation biology endangered species extinction migratory birds South America State of the Birds
alt Simple tips to keep your backyard birds healthy this winter By insider.si.edu Published On :: Fri, 19 Sep 2014 13:58:58 +0000 What crunchy food did Americans spend $5.5 billion on last year—with sales that spiked before snow and ice storms? If you guessed birdseed then you […] The post Simple tips to keep your backyard birds healthy this winter appeared first on Smithsonian Insider. Full Article Science & Nature birds Migratory Bird Center Smithsonian's National Zoo
alt American Indians, colonists had healthy appetite for crabs, study shows By insider.si.edu Published On :: Mon, 02 Feb 2015 15:35:02 +0000 Native Americans and America’s early colonists ate many more blue crabs than modern researchers previously thought, according to a team of scientists studying crab remains […] The post American Indians, colonists had healthy appetite for crabs, study shows appeared first on Smithsonian Insider. Full Article Anthropology Marine Science Research News Science & Nature Chesapeake Bay conservation biology food history National Museum of Natural History Smithsonian Environmental Research Center
alt Human health risks of eating sea turtle eggs could benefit species By insider.si.edu Published On :: Fri, 02 Sep 2016 16:33:17 +0000 According to a new study, eating sea turtle eggs increases the health risk of heavy metal exposure in local communities in Panama and may provide […] The post Human health risks of eating sea turtle eggs could benefit species appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature conservation biology endangered species extinction Tropical Research Institute
alt A Planet in Peril: Q&A with Suzan Murray of the Smithsonian Global Health Program By insider.si.edu Published On :: Mon, 07 Nov 2016 20:41:46 +0000 With roughly 5,500 individuals remaining in the wild, the black rhino population is critically endangered. To help save these iconic African giants, at risk for […] The post A Planet in Peril: Q&A with Suzan Murray of the Smithsonian Global Health Program appeared first on Smithsonian Insider. Full Article Animals Science & Nature mammals Smithsonian's National Zoo veterinary medicine
alt Sirtuin-1 regulates organismal growth by altering feeding behavior and intestinal morphology in planarians [RESEARCH ARTICLE] By jcs.biologists.org Published On :: 2020-04-07T06:45:08-07:00 Benjamin Ziman, Peter Karabinis, Paul Barghouth, and Nestor J. OviedoNutrient availability upon feeding leads to an increase in body size in the planarian Schmidtea mediterranea. However, it remains unclear how food consumption integrates with cell division at the organismal level. Here we show that Sirtuins is evolutionarily conserved in planarians and specifically demonstrate that Sirtuin-1 (Smed-Sirt-1) regulates organismal growth by impairing both feeding behavior and intestinal morphology. Disruption of Smed-Sirt-1 with either RNAi or pharmacological treatment leads to reduced animal growth. Conversely, enhancement of Smed-Sirt-1 with resveratrol accelerates growth. Differences in growth rates were associated with changes in the amount of time to locate food and overall consumption. Furthermore, Smed-Sirt-1(RNAi) animals displayed reduced cell death and increased stem cell proliferation accompanied by impaired expression of intestinal lineage progenitors and reduced branching of the gut. Altogether, our findings indicate Sirtuin-1 is a crucial metabolic hub capable of controlling animal behavior, tissue renewal and morphogenesis of the adult intestine. Full Article
alt National Zoo veterinarian Katharine Hope is in charge of the health of 2,000 animals from 400 different species. By insider.si.edu Published On :: Wed, 23 Feb 2011 13:22:29 +0000 National Zoo Veterinarian Katharine Hope treats about 2,000 animals from 400 different species. She and her colleagues care for a variety of animals, from small baby flamingos to adult Asian elephants, so there's no such thing as an average day. The post National Zoo veterinarian Katharine Hope is in charge of the health of 2,000 animals from 400 different species. appeared first on Smithsonian Insider. Full Article Animals Science & Nature Video amphibian conservation endangered species mammals Smithsonian's National Zoo veterinary medicine
alt Lion cub summer school: Instead of learning their ABCs, the National Zoo’s lion cubs are learning behaviors that will help animal care staff evaluate their health. By insider.si.edu Published On :: Fri, 14 Oct 2011 13:44:51 +0000 School's nearly back in session, but the seven young lions at the Smithsonian's National Zoo have been working hard through the summer months! The post Lion cub summer school: Instead of learning their ABCs, the National Zoo’s lion cubs are learning behaviors that will help animal care staff evaluate their health. appeared first on Smithsonian Insider. Full Article Video mammals Smithsonian's National Zoo veterinary medicine
alt Keeping zoo animals happy, healthy By insider.si.edu Published On :: Mon, 27 Nov 2017 15:02:29 +0000 The zoo extends the collecting mission of the Smithsonian into the realm of the living. From the Series: Stories From the Vault: Random? http://bit.ly/2gfy5hO The post Keeping zoo animals happy, healthy appeared first on Smithsonian Insider. Full Article Animals Science & Nature Video Smithsonian's National Zoo
alt One way businesses are avoiding health care coverage for employees By feeds.scpr.org Published On :: Tue, 20 Aug 2013 12:31:32 -0700 Business Update with Mark LacterBusinesses are cutting back on hours to avoid having to provide health care coverage under the new Affordable Care Act. Steve Julian: Business analyst Mark Lacter, who's affected here? Mark Lacter: Thirty hours a week is the magic number for workers to be considered full time under the new law. If a business has 50 or more full-time employees, health care coverage has to be provided. Except that a lot business owners say that the additional cost is going to be a financial killer, so instead, some of them have been cutting back hours to below that 30-hour threshold. More than 200,000 Californians are at risk of losing hours from the health care law - that according to one study. Julian: What kinds of businesses are doing this? Lacter: Restaurant chains have received much of the attention, but the city of Long Beach, as an example, is going to reduce hours for a couple of hundred of its workers. And, last week came word that the L.A.-based clothing chain Forever 21 will cut some of its full-time employees to a maximum 29-and-a-half hours a week, and classify them as part time. That touched off an outcry on the Internet - people were saying that Forever 21 was being unfair and greedy - though the company says that only a small number of employees are affected, and that its decision has nothing to do with the Affordable Care Act. There's really no way to know - Forever 21 is a private company, which means it's not obligated to disclose a whole lot. What we do know is that those people will be losing their health care coverage. Julian: And, the ultimate impact on businesses and workers? Lacter: Steve, you're looking at several years before the picture becomes clear. Here in California, workers not eligible for health care through their employer can get their own individual coverage, and if their income levels are not over a certain amount, they'd be eligible for Medicaid. And, let's not forget many businesses already provide coverage for their employees. So, lots of rhetoric - but, not many conclusions to draw from, which does make you wonder why so many business owners are unwilling to at least give this thing a chance. Just doesn't seem to be much generosity of spirit for their workers, not to mention any recognition that if people can go to a doctor instead of an emergency room we'd probably all be better off. Julian: Health care is far from the only controversy for Forever 21, true? Lacter: In some ways, it's one of the biggest Southern California success stories. Don Chang emigrated here in 1981 from Korea at the age of 18, opened his first store in Highland Park three years later (it was called Fashion 21), and he never looked back. Today, revenues are approaching $4 billion. But, the guy must have some pretty hefty legal bills because his company has been accused of all kinds of workplace violations. The lawsuits alleged that workers preparing items for the Forever 21 stores didn't receive overtime, that they didn't get required work breaks, that they received substandard wages, and that they worked in dirty and unsafe conditions - sweatshop conditions, essentially. Julian: Are most of their claims settled out of court? You don't hear much about them. Lacter: They are, which means there's usually a minimal amount of media coverage. If a privately held company decides to keep quiet by not releasing financial results or other operational information, there's not likely to be much of a story - unlike what happens with a company like Apple, which is always under scrutiny. Sometimes, plaintiffs will try to organize class-action suits, but that's extremely tough when you're dealing with low-wage workers who are often very reluctant to get involved because of their legal status. And, let's not forget that Forever 21 - like any low-cost retailer - is simply catering to the demand for cheap, stylish clothes that are made as quickly as possible. Julian: I guess you can't make that happen when wages and benefits are appreciably higher than your competition. Lacter: The next time you walk into a Forever 21 store and wonder how prices can be so reasonable, that's how. Mark Lacter writes for Los Angeles Magazine and pens the business blog at LA Observed.com. This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
alt A noisy reef is a healthy reef By insider.si.edu Published On :: Tue, 19 Oct 2010 13:08:31 +0000 Healthy reefs with more corals and fish generate predictably greater levels of noise, according to researchers working in Panama. By analysing recordings of coral reefs from the Las Perlas Archipelago in Pacific Panama ( Central America ), marine biologists working from the Smithsonian Tropical Research Institute have found that some reefs are noisier than others, and these differences in noise provide useful information about the health of the reef. The post A noisy reef is a healthy reef appeared first on Smithsonian Insider. Full Article Animals Marine Science Plants Research News Science & Nature biodiversity conservation conservation biology coral reefs endangered species Tropical Research Institute
alt Coral reefs grow faster, healthier when parrotfish are abundant By insider.si.edu Published On :: Mon, 23 Jan 2017 20:07:05 +0000 Caribbean coral reefs have become biologically and economically degraded habitats. The relative weight of the big factors in this ecological catastrophe–pollution, overfishing, warming and ocean […] The post Coral reefs grow faster, healthier when parrotfish are abundant appeared first on Smithsonian Insider. Full Article Animals Marine Science Plants Science & Nature Spotlight biodiversity conservation conservation biology fishes Smithsonian Tropical Research Institute Tropical Research Institute
alt Recently downloaded some cracked programs. Want to check if Computer is Healthy By www.bleepingcomputer.com Published On :: 2020-05-07T13:46:46-05:00 Full Article
alt 89 percent increase in loyalty program fraud, Forter reveals By feedproxy.google.com Published On :: Tue, 15 Oct 2019 10:47:00 +0200 (The Paypers) Forter has released the seventh edition of its Fraud Attack Index, tracking shifting behaviours... Full Article
alt Halting the mitotic g'1g By jcs.biologists.org Published On :: 2020-04-08 Apr 8, 2020; 133:e0701-e0701RESEARCH HIGHLIGHT Full Article
alt Health Study of Atomic Veterans Families Not Feasible Study Says By feedproxy.google.com Published On :: Fri, 14 Jul 1995 05:00:00 GMT A scientifically accurate and valid epidemiologic study of reproductive problems among the families of veterans exposed to radiation from atomic bombings and nuclear weapons tests is not feasible, concluded an Institute of Medicine (IOM) committee in a new report. Full Article