bluuebunny/crossref_metadata_2025 huggingface dataset:
Healthcare Personnel Attire in Non-Operating-Room Settings
Authors: Bearman Gonzalo , Bryant Kristina , Leekha Surbhi , Mayer Jeanmarie , Munoz-Price L. Silvia , Murthy Rekha , Palmore Tara , Rupp Mark E. , White Joshua
Published: January 2014

Healthcare personnel (HCP) attire is an aspect of the medical profession steeped in culture and tradition. The role of attire in cross-transmission remains poorly established, and until more definitive information exists priority should be placed on evidence-based measures to prevent healthcare-associated infections (HAIs). This article aims to provide general guidance to the medical community regarding HCP attire outside the operating room. In addition to the initial guidance statement, the article has 3 major components: (1) a review and interpretation of the medical literature regarding (a) perceptions of HCP attire (from both HCP and patients) and (b) evidence for contamination of attire and its potential contribution to cross-transmission; (2) a review of hospital policies related to HCP attire, as submitted by members of the Society for Healthcare Epidemiology of America (SHEA) Guidelines Committee; and (3) a survey of SHEA and SHEA Research Network members that assessed both institutional HCP attire policies and perceptions of HCP attire in the cross-transmission of pathogens. Recommendations for HCP attire should attempt to balance professional appearance, comfort, and practicality with the potential role of apparel in the cross-transmission of pathogens. Although the optimal choice of HCP attire for inpatient care remains undefined, we provide recommendations on the use of white coats, neckties, footwear, the bare-below-the-elbows strategy, and laundering. Institutions considering these optional measures should introduce them with a well-organized communication and education effort directed at both HCP and patients. Appropriately designed studies are needed to better define the relationship between HCP attire and HAIs.
Stochastic Perron’s method and verification without smoothness using viscosity comparison: Obstacle problems and Dynkin games
Authors: Bayraktar Erhan , Sîrbu Mihai
Published: January 2014

We adapt the stochastic Perron’s method to the case of double obstacle problems associated to Dynkin games. We construct, symmetrically, a viscosity sub-solution which dominates the upper value of the game and a viscosity super-solution lying below the lower value of the game. If the double obstacle problem satisfies the viscosity comparison property, then the game has a value which is equal to the unique and continuous viscosity solution. In addition, the optimal strategies of the two players are equal to the first hitting times of the two stopping regions, as expected. The (single) obstacle problem associated to optimal stopping can be viewed as a very particular case. This is the first instance of a non-linear problem where the stochastic Perron’s method can be applied successfully.
TheDrosophilainsulin-degrading enzyme restricts growth by modulating the PI3K pathway in a cell-autonomous manner
Authors: Galagovsky Diego , Katz Maximiliano J. , Acevedo Julieta M. , Sorianello Eleonora , Glavic Alvaro , Wappner Pablo
Published: January 2014

Mammalian insulin-degrading enzyme (IDE) cleaves insulin, among other peptidic substrates, but its function in insulin signaling is elusive. We use the Drosophila system to define the function of IDE in the regulation of growth and metabolism. We find that either loss or gain of function of Drosophila IDE (dIDE) can restrict growth in a cell-autonomous manner by affecting both cell size and cell number. dIDE can modulate Drosophila insulin-like peptide 2 levels, thereby restricting activation of the phosphatidylinositol-3-phosphate kinase pathway and promoting activation of Drosophila forkhead box, subgroup O transcription factor. Larvae reared in high sucrose exhibit delayed developmental timing due to insulin resistance. We find that dIDE loss of function exacerbates this phenotype and that mutants display increased levels of circulating sugar, along with augmented expression of a lipid biosynthesis marker. We propose that dIDE is a modulator of insulin signaling and that its loss of function favors insulin resistance, a hallmark of diabetes mellitus type II.
An H3K9/S10 methyl-phospho switch modulates Polycomb and Pol II binding at repressed genes during differentiation
Authors: Sabbattini Pierangela , Sjoberg Marcela , Nikic Svetlana , Frangini Alberto , Holmqvist Per-Henrik , Kunowska Natalia , Carroll Tom , Brookes Emily , Arthur Simon J. , Pombo Ana , Dillon Niall
Published: January 2014

Methylated histones H3K9 and H3K27 are canonical epigenetic silencing modifications in metazoan organisms, but the relationship between the two modifications has not been well characterized. H3K9me3 coexists with H3K27me3 in pluripotent and differentiated cells. However, we find that the functioning of H3K9me3 is altered by H3S10 phosphorylation in differentiated postmitotic osteoblasts and cycling B cells. Deposition of H3K9me3/S10ph at silent genes is partially mediated by the mitogen- and stress-activated kinases (MSK1/2) and the Aurora B kinase. Acquisition of H3K9me3/S10ph during differentiation correlates with loss of paused S5 phosphorylated RNA polymerase II, which is present on Polycomb-regulated genes in embryonic stem cells. Reduction of the levels of H3K9me3/S10ph by kinase inhibition results in increased binding of RNAPIIS5ph and the H3K27 methyltransferase Ezh1 at silent promoters. Our results provide evidence of a novel developmentally regulated methyl-phospho switch that modulates Polycomb regulation in differentiated cells and stabilizes repressed states.
Patient Blood Management in Elective Total Hip- and Knee-replacement Surgery (Part 2)
Authors: So-Osman Cynthia , Nelissen Rob G. H. H. , Koopman-van Gemert Ankie W. M. M. , Kluyver Ewoud , Pöll Ruud G. , Onstenk Ron , Van Hilten Joost A. , Jansen-Werkhoven Thekla M. , van den Hout Wilbert B. , Brand Ronald , Brand Anneke
Published: January 2014

Background:

Patient blood management is introduced as a new concept that involves the combined use of transfusion alternatives. In elective adult total hip- or knee-replacement surgery patients, the authors conducted a large randomized study on the integrated use of erythropoietin, cell saver, and/or postoperative drain reinfusion devices (DRAIN) to evaluate allogeneic erythrocyte use, while applying a restrictive transfusion threshold. Patients with a preoperative hemoglobin level greater than 13 g/dl were ineligible for erythropoietin and evaluated for the effect of autologous blood reinfusion.

Methods:

Patients were randomized between autologous reinfusion by cell saver or DRAIN or no blood salvage device. Primary outcomes were mean intra- and postoperative erythrocyte use and proportion of transfused patients (transfusion rate). Secondary outcome was cost-effectiveness.

Results:

In 1,759 evaluated total hip- and knee-replacement surgery patients, the mean erythrocyte use was 0.19 (SD, 0.9) erythrocyte units/patient in the autologous group (n = 1,061) and 0.22 (0.9) erythrocyte units/patient in the control group (n = 698) (P = 0.64). The transfusion rate was 7.7% in the autologous group compared with 8.3% in the control group (P = 0.19). No difference in erythrocyte use was found between cell saver and DRAIN groups. Costs were increased by €298 per patient (95% CI, 76 to 520).

Conclusion:

In patients with preoperative hemoglobin levels greater than 13 g/dl, autologous intra- and postoperative blood salvage devices were not effective as transfusion alternatives: use of these devices did not reduce erythrocyte use and increased costs.
Mucilaginibacter polytrichastri sp. nov., isolated from a moss (Polytrichastrum formosum), and emended description of the genus Mucilaginibacter
Authors: Chen Xin Yao , Zhao Ran , Tian Yang , Kong Bi He , Li Xue Dong , Chen Zhi Ling , Li Yan Hong
Published: January 2014

A Gram-staining-negative, rod-shaped, non-spore-forming bacterium, designated strain RG4-7T, was isolated from the moss Polytrichastrum formosum collected from Gawalong glacier in Tibet, China, and characterized by using a polyphasic taxonomic approach. The predominant fatty acids of strain RG4-7T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid, two unidentified aminolipids and one unidentified lipid. Strain RG4-7T contained MK-7 as the dominant menaquinone and the G+C content of its genomic DNA was 39.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain RG4-7T was affiliated to species of the genus

Mucilaginibacter

, and its closest relative was

Mucilaginibacter jinjuensis

YC7004T (97.0 % sequence similarity). However, the DNA–DNA relatedness between this strain and strain RG4-7T was only 49.1±3.7 %. Based on phylogenetic inference and phenotypic data, strain RG4-7T is considered to represent a novel species of the genus

Mucilaginibacter

, for which the name Mucilaginibacter polytrichastri sp. nov. is proposed. The type strain is RG4-7T ( = CGMCC 1.12493T = DSM 26907T). An emended description of the genus

Mucilaginibacter

is also proposed.
Aliidiomarina
shirensis sp. nov., a halophilic bacterium isolated from Shira Lake in Khakasia, southern Siberia, and a proposal to transfer Idiomarina maris to the genus Aliidiomarina
Authors: Chiu Hsiu-Hui , Rogozin Denis Yu. , Huang Ssu-Po , Degermendzhy Andrei G. , Shieh Wung Yang , Tang Sen-Lin
Published: January 2014

Strain AIST, an aerobic halophilic, Gram-reaction-negative, heterotrophic bacterium isolated from the water of Shira Lake in Khakasia, southern Siberia, was characterized using a polyphasic approach. Our analysis of the 16S rRNA gene sequences showed that ‘Aliidiomarina haloalkalitolerans’, ‘Aliidiomarina sanyensis’,

Idiomarina maris

and AIST formed a distinct lineage. The sequence similarities between AIST and the type strains of species of the genera

Idiomarina

and

Aliidiomarina

were 91.6–95.1 % and 94.0–96.9 %, respectively. The major isoprenoid quinone of AIST was ubiquinone 8 (Q-8). Predominant cellular fatty acids were iso-C17 : 0, iso-C15 : 0 and summed feature 9. The genomic DNA G+C content was 45.8 mol%. It is concluded that AIST represents a novel species of the genus

Aliidiomarina

, and the name Aliidiomarina shirensis sp. nov. is herein proposed for it. The type strain is AIST ( = JCM 17761T = BCRC 80327T). Based on its fatty acid profile and our phylogenetic analysis, we propose that

Idiomarina maris

be transferred to the genus

Aliidiomarina

.
Evolutionary dynamics and tissue specificity of human long noncoding RNAs in six mammals
Authors: Washietl Stefan , Kellis Manolis , Garber Manuel
Published: January 2014

Long intergenic noncoding RNAs (lincRNAs) play diverse regulatory roles in human development and disease, but little is known about their evolutionary history and constraint. Here, we characterize human lincRNA expression patterns in nine tissues across six mammalian species and multiple individuals. Of the 1898 human lincRNAs expressed in these tissues, we find orthologous transcripts for 80% in chimpanzee, 63% in rhesus, 39% in cow, 38% in mouse, and 35% in rat. Mammalian-expressed lincRNAs show remarkably strong conservation of tissue specificity, suggesting that it is selectively maintained. In contrast, abundant splice-site turnover suggests that exact splice sites are not critical. Relative to evolutionarily young lincRNAs, mammalian-expressed lincRNAs show higher primary sequence conservation in their promoters and exons, increased proximity to protein-coding genes enriched for tissue-specific functions, fewer repeat elements, and more frequent single-exon transcripts. Remarkably, we find that ∼20% of human lincRNAs are not expressed beyond chimpanzee and are undetectable even in rhesus. These hominid-specific lincRNAs are more tissue specific, enriched for testis, and faster evolving within the human lineage.
Persistent prelimbic cortex activity contributes to enhanced learned fear expression in females
Authors: Fenton Georgina E. , Pollard Amelia K. , Halliday David M. , Mason Rob , Bredy Timothy W. , Stevenson Carl W.
Published: January 2014

Anxiety disorders, such as post-traumatic stress, are more prevalent in women and are characterized by impaired inhibition of learned fear and medial prefrontal cortex (mPFC) dysfunction. Here we examined sex differences in fear extinction and mPFC activity in rats. Females showed more learned fear expression during extinction and its recall, but not fear conditioning. They also showed more spontaneous fear recovery and more contextual fear before extinction and its recall. Moreover, enhanced learned fear expression in females was associated with sustained prelimbic (PL) cortex activity. These results suggest that sex differences in learned fear expression may involve persistent PL activation.
Crystallographic analysis of 1,2,3-trichloropropane biodegradation by the haloalkane dehalogenase DhaA31
Authors: Lahoda Maryna , Mesters Jeroen R. , Stsiapanava Alena , Chaloupkova Radka , Kuty Michal , Damborsky Jiri , Kuta Smatanova Ivana
Published: January 2014

Haloalkane dehalogenases catalyze the hydrolytic cleavage of carbon–halogen bonds, which is a key step in the aerobic mineralization of many environmental pollutants. One important pollutant is the toxic and anthropogenic compound 1,2,3-trichloropropane (TCP). Rational design was combined with saturation mutagenesis to obtain the haloalkane dehalogenase variant DhaA31, which displays an increased catalytic activity towards TCP. Here, the 1.31 Å resolution crystal structure of substrate-free DhaA31, the 1.26 Å resolution structure of DhaA31 in complex with TCP and the 1.95 Å resolution structure of wild-type DhaA are reported. Crystals of the enzyme–substrate complex were successfully obtained by adding volatile TCP to the reservoir after crystallization at pH 6.5 and room temperature. Comparison of the substrate-free structure with that of the DhaA31 enzyme–substrate complex reveals that the nucleophilic Asp106 changes its conformation from an inactive to an active state during the catalytic cycle. The positions of three chloride ions found inside the active site of the enzyme indicate a possible pathway for halide release from the active site through the main tunnel. Comparison of the DhaA31 variant with wild-type DhaA revealed that the introduced substitutions reduce the volume and the solvent-accessibility of the active-site pocket.
Understanding the highly efficient catalysis of prokaryotic peptide deformylases by shedding light on the determinants specifying the low activity of the human counterpart
Authors: Fieulaine Sonia , Desmadril Michel , Meinnel Thierry , Giglione Carmela
Published: January 2014

Peptide deformylases (PDFs), which are essential and ubiquitous enzymes involved in the removal of theN-formyl group from nascent chains, are classified into four subtypes based on the structural and sequence similarity of specific conserved domains. All PDFs share a similar three-dimensional structure, are functionally interchangeablein vivoand display similar propertiesin vitro, indicating that their molecular mechanism has been conserved during evolution. The human mitochondrial PDF is the only exception as despite its conserved fold it reveals a unique substrate-binding pocket together with an unusual kinetic behaviour. Unlike human PDF, the closely related mitochondrial PDF1As from plants have catalytic efficiencies and enzymatic parameters that are similar to those of other classes of PDFs. Here, the aim was to identify the structural basis underlying the properties of human PDF compared with all other PDFs by focusing on plant mitochondrial PDF1A. The construction of a chimaera composed of plant PDF1A with the nonrandom substitutions found in a conserved motif of its human homologue converted it into an enzyme with properties similar to the human enzyme, indicating the crucial role of these positions. The crystal structure of this human-like plant PDF revealed that substitution of two residues leads to a reduction in the volume of the ligand-binding site together with the introduction of negative charges, unravelling the origin of the weak affinity of human PDF for its substrate. In addition, the substitution of the two residues of human PDF modifies the transition state of the reaction through alteration of the network of interactions between the catalytic residues and the substrate, leading to an overall reduced reaction rate.
1-Ethyl-3-methyl-1H-imidazol-3-ium spiropentaborate
Authors: Parker T. Gannon , Pubbi Divya , Beehler Austin , Albrecht-Schmitt Thomas E.
Published: January 2014

In the anion of the title compound, (C6H11N2)[B5O6(OH)4], both six-membered borate rings adopt a flattened boat conformation with the spiro-B atom and its opposite O atom deviating from the remainders of the rings by 0.261 (3)/0.101 (2) and 0.160 (3)/0.109 (2) Å, respectively. The imidazolium cation also deviates from planarity due to rotation of the ethyl group (as indicated by the C—N—C—C torsion angle) by 71.4 (2)° out of the plane of the heterocycle. In the crystal, the anions are connected in a three-dimensional network through O—H...O hydrogen bonds, forming channels along thea-axis direction. The cations are situated in the channels, forming C—H...O hydrogen bonds with the anions.
(E)-3-(4-Heptyloxyphenyl)-1-phenylprop-2-en-1-one
Authors: McKoy Davia , Franks Marion A. , Assefa Zerihun
Published: January 2014

In the title compound, C22H26O2, the aromatic rings are inclined to one another by 8.39 (9)° and the molecule has anEconformation about the C=C bond. In the crystal, molecules stack head-to-tail along theb-axis direction. They are linked by very weak C—H...O contacts, formingC(4) chains along [100]. Two chains are linked by a pair of very weak C—H...O contacts, enclosing inversion-dimericR22(8) ring motifs. There are also C—H...π interactions present, which link the double-stranded chains, forming a two-dimensional network.
(4S)-3-Methyl-5,6,7,8-tetrahydro-4H-spiro[[1,2]oxazolo[5,4-b]quinoline-4,3′-indole]-2′,5-dione
Authors: Govindan E. , Yuvaraj P. S. , Reddy B. S. R. , Bangaru Sudarsan Alwar S. , SubbiahPandi A.
Published: January 2014

In the title compound, C18H15N3O3, the dihedral angle between the mean planes of the quinoline and indole ring systems [r.m.s. deviations = 0.189 (2) and 0.027 (2) Å, respectively] is 88.65 (5)°. The cyclohexene ring of the quinoline ring system adopts an envelope conformation with the central –CH2– C atom as the flap. In the crystal, molecules are linked by two pairs of N—H...O hydrogen bonds, forming inversion dimers, and enclosingR22(14) ring motifs. This arrangement results in the formation of chains propagating along [100].
Poly[[diaquadeca-μ2-cyanido-κ20C:N-hexacyanido-κ6C-bis(μ2-5-methylpyrimidine-κ2N:N′)bis(5-methylpyrimidine-κN)tricopper(II)ditungstate(V)] dihydrate]
Authors: Tsunobuchi Yoshihide , Kaneko Souhei , Nakabayashi Koji , Ohkoshi Shin-ichi
Published: January 2014

In the title complex, {[Cu3[W(CN)8]2(C5H6N2)4(H2O)2]·2H2O}n, the coordination polyhedron of the eight-coordinated WVatom is a bicapped trigonal prism, in which five CN groups are bridged to CuIIions, and the other three CN groups are terminally bound. Two of the CuIIions lie on a centre of inversion and each of the three independent CuIIcations is pseudo-octahedrally coordinated. In the crystal structure, cyanido-bridged-Cu—W—Cu layers are linked by pillars involving the third independent CuIIion, generating a three-dimensional network with non-coordinating water molecules and 5-methylpyrimidine molecules. O—H...O and O—H...N hydrogen bonds involve the coordinating and non-coordinating water molecules, the CN groups and the 5-methylpyrimidine molecules.
1,4-Diazabicyclo[2.2.2]octane-1,4-diium bis(3-chlorobenzoate)
Authors: Yao Zi-Shuo , Sato Osamu
Published: January 2014

In the title salt C6H14N22+·2C7H4ClO2−, two 3-chlorobenzoate (3CBA) anions are bridged by one diprotonated 1,4-diazabicyclo[2.2.2]octane-1,4-diium (H2DABCO2+) dication through N—H...O hydrogen bonds. In this way, a trimeric unit is generated, in which the mean planes of the two 3CBA anions are twisted with respect to each other by a dihedral angle of 59.87 (9)°. The trimeric units are linked into a three-dimensional networkviaweak C—H...O interactions.
β-Li0.37Na0.63Fe(MoO4)2
Authors: Souilem Amira , Zid Mohamed Faouzi , Driss Ahmed
Published: January 2014

The title compound, lithium/sodium iron(III) bis[orthomolybdate(VI)], was obtained by a solid-state reaction. The main structure units are an FeO6octahedron, a distorted MoO6octahedron and an MoO4tetrahedron sharing corners. The crystal structure is composed of infinite double MoFeO11chains along theb-axis direction linked by corner-sharing to MoO4tetrahedra so as to form Fe2Mo3O19ribbons. The cohesion between ribbonsviamixed Mo—O—Fe bridges leads to layers arranged parallel to thebcplane. Adjacent layers are linked by corners shared between MoO4tetrahedra of one layer and FeO6octahedra of the other layer. The Na+and Li+ions partially occupy the same general position, with a site-occupancy ratio of 0.631 (9):0.369 (1). A comparison is made withAFe(MoO4)2(A= Li, Na, K and Cs) structures.
2-(1,3-Benzodioxol-5-yl)-1H-benzimidazole
Authors: Ghichi Nadir , Benaouida Mohamed Amine , Benosmane Ali , Benboudiaf Ali , Merazig Hocine
Published: January 2014

The asymmetric unit of the title compound, C14H10N2O2, contains two independent molecules. In each molecule, the benzodioxole ring system displays an envelope conformation, with the methylene C atom located at the flap deviating by 0.081 (2) and 0.230 (2) Å from the mean plane formed by the other atoms. The dihedral angles between the benzoimidazole ring system (all atoms) and the benzodioxole benzene ring are 15.35 (6) and 10.99 (7)°. In the crystal, molecules are linked by N—H...N hydrogen bonds into chains running along the [101].
[1,4-Bis(diphenylphosphanyl)butane-κ2P,P′]dibromidopalladium(II)
Authors: Ha Kwang , Song Yo Soon
Published: January 2014

In the title complex, [PdBr2(C28H28P2)], the PdIIion has a distortedcis-Br2P2square-planar coordination geometry defined by two P atoms from the chelating 1,4-bis(diphenylphosphanyl)butane ligand and two Br−anions. The four phenyl rings are inclined to the least-squares plane of the PdBr2P2unit [maximum deviation = 0.1294 (7) Å], making dihedral angles of 66.3 (2), 87.2 (2), 68.8 (2) and 86.8 (2)°. The butylene chain is in agaucheconformation, with a C—C—C—C torsion angle of 57.0 (8)°. Intermolecular C—H...Br hydrogen bonds link the complex molecules into supramolecular layers in theabplane. Weak π–π interactions, both intra- and intermolecular [shortest inter-centroid distance = 4.598 (5) Å], are also noted in the three-dimensional architecture.
4-[(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]-2H-1,4-benzothiazin-3(4H)-one
Authors: Sebbar Nada Kheira , Zerzouf Abdelfettah , Essassi El Mokhtar , Saadi Mohamed , El Ammari Lahcen
Published: January 2014

In the title compound, C18H16N4OS, the six-membered heterocycle of the benzothiazine fragment exhibits a screw-boat conformation. The dihedral angles between the plane through the triazole ring and those through the fused and terminal benzene rings are 76.68 (11) and 71.0 (1)°, respectively; the benzene rings are nearly perpendicular [dihedral angle = 79.6 (1)°]. In the crystal, molecules are linked by C—H...N and C—H...O interactions, forming a three-dimensional network.
Kikuchi bandlet method for the accurate deconvolution and localization of Kikuchi bands in Kikuchi diffraction patterns
Authors: Ram Farangis , Zaefferer Stefan , Raabe Dierk
Published: January 2014

In order to retrieve crystallographic information from an electron backscatter Kikuchi diffraction pattern, its Kikuchi bands have to be localized. One of the main reasons for the limited precision of the present Kikuchi band localization methods is that the diffuse edges of a Kikuchi band are convoluted by many other Kikuchi bands that intersect them. To improve the localization accuracy, Kikuchi bands have to be deconvoluted. In this article, a new method for the deconvolution and localization of Kikuchi bands is presented. The deconvolution is based on the fact that, in a Kikuchi pattern, there are a number of Kikuchi bands that are not parallel to the bands that intersect them. It is performed in Fourier space. After deconvolution, localization is carried out by a quantitative shape analysis of the intensity profiles of the deconvoluted Kikuchi bands. Using the introduced method, for a real electron backscatter Kikuchi diffraction pattern with 45° half capture angle and 0.12° per pixel maximum scale factor, the characteristic hyperbolic features of the Kikuchi bands can be localized with a precision of better than 0.1° in reflection angle.
Analysis of reciprocal space maps of GaN(0001) films grown by molecular beam epitaxy
Authors: Kopp Viktor S. , Kaganer Vladimir M. , Jenichen Bernd , Brandt Oliver
Published: January 2014

The reciprocal space map of a heteroepitaxial single-crystal GaN(0001) film on 6H-SiC(0001) is analyzed. The film contains a high density of threading dislocations which intersect the film parallel to the surface normal. The strain field associated with these dislocations is expected to broaden all reciprocal lattice points to discs perpendicular to the dislocation lines,i.e.parallel to the surface. Experimentally, however, the reflection is observed to be broadened also perpendicular to the surface and is rotated towards the surface normal. Using Monte Carlo simulations, it is shown that both of these features are a natural consequence of the presence of misfit dislocations at the film/substrate interface.
A novel three-dimensional ZnIIcoordination polymer with 1,3,5-tris(imidazol-1-ylmethyl)benzene and cyclohexane-1,3,5-tricarboxylate ligands
Authors: Zhong Kai-Long
Published: January 2014

In the ZnIIcompound poly[[bis(μ3-cyclohexane-1,3,5-tricarboxylato)bis[μ3-1,3,5-tris(imidazol-1-ylmethyl)benzene]trizinc(II)] hexahydrate], {[Zn3(C18H18N6)2(C9H9O6)2]·6H2O}n, based on mixed 1,3,5-tris(imidazol-1-ylmethyl)benzene and cyclohexane-1,3,5-tricarboxylate ligands, there are two types of crystallographically independent ZnIIcentres, one in a general position and one on a crystallographic twofold axis. They have similar fourfold distorted tetrahedral coordination geometries, ligated by two monodentate carboxylate groups from two cyclohexane-1,3,5-tricarboxylate ligands and by two N atoms from two 1,3,5-tris(imidazol-1-ylmethyl)benzene ligands. The cyclohexane-1,3,5-tricarboxylate anions link the ZnIIcations to generate a two-dimensional layered metal–organic structure running parallel to the (\overline{2}01) plane. Adjacent layers are further connected by tripodal 1,3,5-tris(imidazol-1-ylmethyl)benzene ligands, resulting in a three-dimensional network. The solvent water molecules are linked to the cyclohexane-1,3,5-tricarboxylate ligandsviawater–carboxylate O—H...O hydrogen bonds.
Poly[tetrachlorido{μ4-tetrakis[(imidazol-1-yl)methyl]methane-κ4N3:N3′:N3′′:N3′′′}dizinc(II)] exhibiting a three-dimensional diamond topology
Authors: Su Jian , Yao Liu-Di , Zhang Jun , Wu Jie-Ying , Tian Yu-Peng
Published: January 2014

The title novel noncentrosymmetric metal–organic framework, [Zn2Cl4(C17H20N8)]n, was prepared solvothermally using the tetradentate tetrakis[(imidazol-1-yl)methyl]methane (tiym) linker in the presence of zinc nitrate under acidic conditions. The asymmetric unit contains one ZnIIcation, two Cl−anions and a quarter of each of two symmetry-independent tiym ligands. Each ZnIIcation is four-coordinated by two Cl−anions and two imidazole N atoms from two tiym ligands, forming a distorted tetrahedral coordination geometry. The tetrahedral tetradentate tiym linker has a quaternary C atom located on a crystallographic \overline{4} axis. With its four peripheral imidazole N atoms, the linkers are bridged by four [ZnCl2] subunits to generate a three-dimensional diamond topological framework, which is represented by the Schläfli symbol {66}. To the best of our knowledge, the title compound is the first example of a non-interpenetrating diamond net based on the tiym ligand.
Nutritional benefits from domatia inhabitants in an ant–plant interaction: interlopers do pay the rent
Authors: Chanam Joyshree , Sheshshayee Madavalam Sreeman , Kasinathan Srinivasan , Jagdeesh Amaraja , Joshi Kanchan A. , Borges Renee M.
Published: January 2014

How a symbiosis originates and is maintained are important evolutionary questions. Symbioses in myrmecophytes (plants providing nesting for ants) are believed to be maintained by protection and nutrients provided by specialist plant‐ants in exchange for nesting spaces (called domatia) and nourishment offered by ant‐plants. However, besides the benefits accrued from housing protective ants, the mechanisms contributing to the fitness advantages of bearing domatia have rarely been examined, especially because the domatia trait is usually constitutively expressed, and many myrmecophytes have obligate mutualisms with single ant species resulting in invariant conditions.

In the unspecialized ant‐plant Humboldtia brunonis (Fabaceae) that offers extrafloral nectar to ants, only some plants produce domatia in the form of hollow internodes. These domatia have a self‐opening slit making them more prone to interlopers and are occupied mostly by non‐protective ants and other invertebrates, especially arboreal earthworms. The protection mutualism with ants is restricted in geographical extent, occurring only at a few sites in the southernmost part of this plant's range in the Western Ghats of India.

We examined nutrient flux from domatia residents to the plant using stable isotopes. We found that between 9% (earthworms) and 17% (protective or non‐protective ants) of nitrogen of plant tissues nearest the domatium came from domatia inhabitants. Therefore, interlopers such as earthworms and non‐protective ants contributed positively to the nitrogen budget of localized plant modules of this understorey tree. 15N‐enriched feeding experiments with protective ants demonstrated that nutrients flowed from domatia inhabitants to nearby plant modules. Fruit set did not differ between paired hand‐pollinated inflorescences on domatia and non‐domatia bearing branches. This was possibly due to the nutrient flux from domatia to adjacent branches without domatia within localized modules.

This study has demonstrated the nutritive role of non‐protective ants and non‐ant invertebrates, hitherto referred to as interlopers, in an unspecialized myrmecophyte. Our study suggests that even before the establishment of a specialized ant–plant protection mutualism, nutritional benefits conferred by domatia inhabitants can explain the fitness benefits of bearing domatia, and thus the maintenance of a trait that facilitates the establishment of a specialized ant–plant symbiosis.
Co‐localization of insect olfactory sensory cells improves the discrimination of closely separated odour sources
Authors: Binyameen Muhammad , Jankuvová Júlia , Blaženec Miroslav , Jakuš Rastislav , Song Liwen , Schlyter Fredrik , Andersson Martin N.
Published: January 2014

The sense of smell is crucial for fitness of most animals, enabling them to find mates, food and egg laying sites and to stay away from danger. Hence, odour molecules are detected by sensitive and specific olfactory sensory neurons (OSNs). In insects, the OSNs are stereotypically grouped into olfactory sensilla located mainly on the antennae. The functional significance of this co‐localization principle is poorly understood, but it has been hypothesized that it allows for coincidence detection of odour filaments, improving discrimination of closely separated odour sources.

Using an insect in its natural environment, we conducted the first experimental test of the hypothesis. We manipulated the distance between odour sources of an attractive pheromone and either of two host‐derived attraction antagonists (1,8‐cineole and verbenone) and investigated the effect on trap catches of the bark beetle, Ips typographus (Coleoptera). 1,8‐Cineole is detected by an OSN co‐localized with an OSN for one of the pheromone components, while verbenone is detected by OSNs in other sensilla, not co‐localized with pheromone OSNs.

Consistent with the hypothesis, trap catch increased with distance between odour sources more for 1,8‐cineole than for verbenone. The strongest effect was found among the males, that is the sex that first locates and attacks the host tree.

Our data from the beetle provide, for the first time, direct experimental support for the hypothesis that co‐localization of OSNs in sensilla improves the discrimination of closely separated odour sources. Thus, selection for improved odour source discrimination could well be one of the factors explaining the strict co‐localization of OSNs that is seen across the Insecta class.
A critical examination of indices of dynamic interaction for wildlife telemetry studies
Authors: Long Jed A. , Nelson Trisalyn A. , Webb Stephen L. , Gee Kenneth L.
Published: January 2014

Wildlife scientists continue to be interested in studying ways to quantify how the movements of animals are interdependent – dynamic interaction. While a number of applied studies of dynamic interaction exist, little is known about the comparative effectiveness and applicability of available methods used for quantifying interactions between animals.

We highlight the formulation, implementation and interpretation of a suite of eight currently available indices of dynamic interaction. Point‐ and path‐based approaches are contrasted to demonstrate differences between methods and underlying assumptions on telemetry data.

Correlated and biased correlated random walks were simulated at a range of sampling resolutions to generate scenarios with dynamic interaction present and absent. We evaluate the effectiveness of each index at identifying different types of interactive behaviour at each sampling resolution. Each index is then applied to an empirical telemetry data set of three white‐tailed deer (Odocoileus virginianus) dyads.

Results from the simulated data show that three indices of dynamic interaction reliant on statistical testing procedures are susceptible to Type I error, which increases at fine sampling resolutions. In the white‐tailed deer examples, a recently developed index for quantifying local‐level cohesive movement behaviour (the di index) provides revealing information on the presence of infrequent and varying interactions in space and time.

Point‐based approaches implemented with finely sampled telemetry data overestimate the presence of interactions (Type I errors). Indices producing only a single global statistic (7 of the 8 indices) are unable to quantify infrequent and varying interactions through time. The quantification of infrequent and variable interactive behaviour has important implications for the spread of disease and the prevalence of social behaviour in wildlife. Guidelines are presented to inform researchers wishing to study dynamic interaction patterns in their own telemetry data sets. Finally, we make our code openly available, in the statistical software R, for computing each index of dynamic interaction presented herein.
Multiple dimensions of bat biodiversity along an extensive tropical elevational gradient
Authors: Cisneros Laura M. , Burgio Kevin R. , Dreiss Lindsay M. , Klingbeil Brian T. , Patterson Bruce D. , Presley Steven J. , Willig Michael R.
Published: January 2014

Research concerning spatial dynamics of biodiversity generally has been limited to considerations of the taxonomic dimension, which is insensitive to interspecific variation in ecological or evolutionary characteristics that play important roles in species assembly and provide linkages to ecosystem services. Consequently, the assumption that the taxonomic dimension is a good surrogate for other dimensions remains unconfirmed.

We assessed variation in taxonomic (species richness) as well as phylogenetic and functional (Rao's quadratic entropy, a measurement of dispersion) dimensions of bat biodiversity along an elevational gradient in the Manu Biosphere Reserve of Peru. Phylogenetic dispersion was based on relatedness of species derived from a mammalian supertree. Functional dispersion was estimated separately for each of six functional components that reflect particular niche axes (e.g. diet, foraging strategy, body size) and for all functional components combined.

Species richness declined nonlinearly with elevation, whereas phylogenetic dispersion and functional dispersion based on all functional components were not significantly associated with elevation (orthogonal polynomial regression). Moreover, considerable heterogeneity in the form of elevational relationships existed among functional components. After accounting for variation in species richness, dispersion of phylogenetic, diet and foraging strategy attributes were significantly greater than expected at high elevations, whereas dispersion of body size was significantly less than expected at high elevations.

Species richness was a poor surrogate for phylogenetic or functional dispersion. Functional dispersion based on multiple components obscured patterns detected by particular components and hindered identification of mechanistic explanations for elevational variation in biodiversity.

Variation in phylogenetic dispersion effectively captured the composite variation represented by all functional components, suggesting a phylogenetic signal in functional attributes.

Mechanisms that give rise to variation in richness do not fully account for variation in phylogenetic or functional characteristics of assemblages. Greater than expected phylogenetic, diet and foraging strategy dispersion at high elevations were associated with the loss of phylogenetically or functionally redundant species, suggesting that increasing interspecific competition with decreasing productivity resulted in competitive exclusion. In contrast, low dispersion of size attributes at high elevations suggests the importance of abiotic filtering that favours small‐sized species that can more easily enter torpor.
Evidence for horizontal transmission from multilocus phylogeny of deep‐sea mussel (Mytilidae) symbionts
Authors: Fontanez Kristina M. , Cavanaugh Colleen M.
Published: January 2014

Many invertebrates at deep‐sea hydrothermal vents depend upon bacterial symbionts for nutrition, and thus the mechanism of symbiont transmission, vertical (via the egg or sperm) or horizontal (from environment or contemporary hosts) is critically important. Under a strict maternal transmission model, symbiont and host mitochondrial genomes pass through the same individuals leading to congruent host–symbiont phylogenies. In contrast, horizontally transmitted symbionts are environmentally acquired, leading to incongruent host–symbiont phylogenies. Each of these transmission strategies is predicted to have different consequences for symbiont ecology and genome evolution. Deep‐sea mussels (Bathymodiolinae) are globally distributed at deep‐sea hydrothermal vents, depend upon chemoautotrophic symbionts for their survival, and are hypothesized to transmit their symbionts horizontally. This study explored bathymodioline symbiont ecology through quantification of symbionts at two hydrothermal vent sites and symbiont evolution using functional gene phylogenies. These phylogenies revealed a dramatically more complex evolutionary history than 16S ribosomal RNA phylogenies, suggesting that horizontal gene transfer may have played an important role in symbiont gene evolution. Tests of the strict maternal transmission hypothesis found that host–symbiont lineages were significantly decoupled across multiple genes. These findings expand our understanding of symbiont ecology and evolution, and provide the strongest evidence yet for horizontal transmission of bathymodioline symbionts.
Exploring Anopheles gut bacteria for Plasmodium blocking activity
Authors: Bahia Ana C. , Dong Yuemei , Blumberg Benjamin J. , Mlambo Godfree , Tripathi Abhai , BenMarzouk‐Hidalgo Omar J. , Chandra Ramesh , Dimopoulos George
Published: January 2014

Malaria parasite transmission requires the successful development of Plasmodium gametocytes into flagellated microgametes upon mosquito blood ingestion, and the subsequent fertilization of microgametes and macrogametes for the development of motile zygotes, called ookinetes, which invade and transverse the Anopheles vector mosquito midgut at around 18–36 h after blood ingestion. Within the mosquito midgut, the malaria parasite has to withstand the mosquito's innate immune response and the detrimental effect of its commensal bacterial flora. We have assessed the midgut colonization capacity of five gut bacterial isolates from field‐derived, and two from laboratory colony, mosquitoes and their effect on Plasmodium development in vivo and in vitro, along with their impact on mosquito survival. Some bacterial isolates activated the mosquito's immune system, affected the mosquito's lifespan, and were capable of blocking Plasmodium development. We have also shown that the ability of these bacteria to inhibit the parasites is likely to involve different mechanisms and factors. A Serratia marcescens isolate was particularly efficient in colonizing the mosquitoes' gut, compromising mosquito survival and inhibiting both Plasmodium sexual‐ and asexual‐stage through secreted factors, thereby rendering it a potential candidate for the development of a malaria transmission intervention strategy.
Tropical tephritid fruit fly community with high incidence of shared Wolbachia strains as platform for horizontal transmission of endosymbionts
Authors: Morrow J. L. , Frommer M. , Shearman D. C. A. , Riegler M.
Published: January 2014

Wolbachia are endosymbiotic bacteria that infect 40–65% of arthropod species. They are primarily maternally inherited with occasional horizontal transmission for which limited direct ecological evidence exists. We detected Wolbachia in 8 out of 24 Australian tephritid species. Here, we have used multilocus sequence typing (MLST) to further characterize these Wolbachia strains, plus a novel quantitative polymerase chain reaction method for allele assignment in multiple infections. Based on five MLST loci and the Wolbachia surface protein gene (wsp), five Bactrocera and one Dacus species harboured two identical strains as double infections; furthermore, Bactrocera neohumeralis harboured both of these as single or double infections, and sibling species B. tryoni harboured one. Two Bactrocera species contained Wolbachia pseudogenes, potentially within the fruit fly genomes. A fruit fly parasitoid, Fopius arisanus shared identical alleles with two Wolbachia strains detected in one B. frauenfeldi individual. We report an unprecedented high incidence of four shared Wolbachia strains in eight host species from two trophic levels. This suggests frequent exposure to Wolbachia in this tropical tephritid community that shares host plant and parasitoid species, and also includes species that hybridize. Such insect communities may act as horizontal transmission platforms that contribute to the ubiquity of the otherwise maternally inherited Wolbachia.
Rare but active taxa contribute to community dynamics of benthic biofilms in glacier‐fed streams
Authors: Wilhelm Linda , Besemer Katharina , Fasching Christina , Urich Tim , Singer Gabriel A. , Quince Christopher , Battin Tom J.
Published: January 2014

Glaciers harbour diverse microorganisms, which upon ice melt can be released downstream. In glacier‐fed streams microorganisms can attach to stones or sediments to form benthic biofilms. We used 454‐pyrosequencing to explore the bulk (16S rDNA) and putatively active (16S rRNA) microbial communities of stone and sediment biofilms across 26 glacier‐fed streams. We found differences in community composition between bulk and active communities among streams and a stronger congruence between biofilm types. Relative abundances of rRNA and rDNA were positively correlated across different taxa and taxonomic levels, but at lower taxonomic levels, the higher abundance in either the active or the bulk communities became more apparent. Here, environmental variables played a minor role in structuring active communities. However, we found a large number of rare taxa with higher relative abundances in rRNA compared with rDNA. This suggests that rare taxa contribute disproportionately to microbial community dynamics in glacier‐fed streams. Our findings propose that high community turnover, where taxa repeatedly enter and leave the ‘seed bank’, contributes to the maintenance of microbial biodiversity in harsh ecosystems with continuous environmental perturbations, such as glacier‐fed streams.
Lon protease negatively affects GacA protein stability and expression of the Gac/Rsm signal transduction pathway in Pseudomonas protegens
Authors: Takeuchi Kasumi , Tsuchiya Wataru , Noda Naomi , Suzuki Rintaro , Yamazaki Toshimasa , Haas Dieter
Published: January 2014

In Pseudomonas protegens CHA0 and other fluorescent pseudomonads, the Gac/Rsm signal transduction pathway controls secondary metabolism and suppression of fungal root pathogens via the expression of regulatory small RNAs (sRNAs). Because of its high cost, this pathway needs to be protected from overexpression and to be turned off in response to environmental stress such as the lack of nutrients. However, little is known about its underlying molecular mechanisms. In this study, we demonstrated that Lon protease, a member of the ATP‐dependent protease family, negatively regulated the Gac/Rsm cascade. In a lon mutant, the steady‐state levels and the stability of the GacA protein were significantly elevated at the end of exponential growth. As a consequence, the expression of the sRNAs RsmY and RsmZ and that of dependent physiological functions such as antibiotic production were significantly enhanced. Biocontrol of Pythium ultimum on cucumber roots required fewer lon mutant cells than wild‐type cells. In starved cells, the loss of Lon function prolonged the half‐life of the GacA protein. Thus, Lon protease is an important negative regulator of the Gac/Rsm signal transduction pathway in P. protegens.
Functional analyses of three acyl‐CoA synthetases involved in bile acid degradation in Pseudomonas putida DOC21
Authors: Barrientos Álvaro , Merino Estefanía , Casabon Israël , Rodríguez Joaquín , Crowe Adam M. , Holert Johannes , Philipp Bodo , Eltis Lindsay D. , Olivera Elías R. , Luengo José M.
Published: January 2014

Pseudomonas putida DOC21, a soil‐dwelling proteobacterium, catabolizes a variety of steroids and bile acids. Transposon mutagenesis and bioinformatics analyses identified four clusters of steroid degradation (std) genes encoding a single catabolic pathway. The latter includes three predicted acyl‐CoA synthetases encoded by stdA1, stdA2 and stdA3 respectively. The ΔstdA1 and ΔstdA2 deletion mutants were unable to assimilate cholate or other bile acids but grew well on testosterone or 4‐androstene‐3,17‐dione (AD). In contrast, a ΔstdA3 mutant grew poorly in media containing either testosterone or AD. When cells were grown with succinate in the presence of cholate, ΔstdA1 accumulated Δ1/4‐3‐ketocholate and Δ1,4‐3‐ketocholate, whereas ΔstdA2 only accumulated 7α,12α‐dihydroxy‐3‐oxopregna‐1,4‐diene‐20‐carboxylate (DHOPDC). When incubated with testosterone or bile acids, ΔstdA3 accumulated 3aα‐H‐4α(3′propanoate)‐7aβ‐methylhexahydro‐1,5‐indanedione (HIP) or the corresponding hydroxylated derivative. Biochemical analyses revealed that StdA1 converted cholate, 3‐ketocholate, Δ1/4‐3‐ketocholate, and Δ1,4‐3‐ketocholate to their CoA thioesters, while StdA2 transformed DHOPDC to DHOPDC‐CoA. In contrast, purified StdA3 catalysed the CoA thioesterification of HIP and its hydroxylated derivatives. Overall, StdA1, StdA2 and StdA3 are acyl‐CoA synthetases required for the complete degradation of bile acids: StdA1 and StdA2 are involved in degrading the C‐17 acyl chain, whereas StdA3 initiates degradation of the last two steroid rings. The study highlights differences in steroid catabolism between Proteobacteria and Actinobacteria.