bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of associative strength and conceptual relations in matching tasks in 4‐ and 6‐year‐old children
Authors: Scheuner Nelly , Bonthoux Françoise , Cannard Christine , Blaye Agnès
Published: August 2008

The associative strength between target and associates, a factor assumed to be critical but generally not controlled, and the type of conceptual relation (thematic and taxonomic) were manipulated independently in a matching to sample task to determine their respective effects on the matching behaviour of 4‐ and 6‐year‐old children. Perceptual similarity between target and associates was controlled and maintained at a low level. A preliminary task was designed to assess the associative strength between targets and several associated pictures. These judgments served to construct for each child the sets of stimuli used in the matching task. Exp. 1 opposed a strong and a weak associate with the target in different configurations: the sets included a target and two thematic associates, two taxonomic associates, or one associate of each type. Children were asked to choose the picture that “went well” with the target. Data revealed the role of associative strength on matching choices. This factor interacted sometimes with the greater availability of thematic relations in 4‐ and 6‐year‐old children. In Exp. 2, two other configurations were tested. Thematic and taxonomic associates were both either strongly or weakly related with the target. Results replicated those of Exp. 1 and extended them. They showed that younger children were biased towards thematic relations only when these relations corresponded to strong associations. Thus, increasing experience with objects appears to reinforce both associative strength and thematic orientation. Finally, in Exp. 3, instructions orienting toward taxonomic choices modified responses in 6‐year‐olds only. Altogether, these results show the influence of specific instances and suggest that preschoolers' matching decisions are partly stimulus driven.
Reciprocal interaction with G-actin and tropomyosin is essential for aquaporin-2 trafficking
Authors: Noda Yumi , Horikawa Saburo , Kanda Eiichiro , Yamashita Maho , Meng Hu , Eto Kayoko , Li Yuhua , Kuwahara Michio , Hirai Keiji , Pack Changi , Kinjo Masataka , Okabe Shigeo , Sasaki Sei
Published: August 2008

Trafficking of water channel aquaporin-2 (AQP2) to the apical membrane and its vasopressin and protein kinase A (PKA)–dependent regulation in renal collecting ducts is critical for body water homeostasis. We previously identified an AQP2 binding protein complex including actin and tropomyosin-5b (TM5b). We show that dynamic interactions between AQP2 and the actin cytoskeleton are critical for initiating AQP2 apical targeting. Specific binding of AQP2 to G-actin in reconstituted liposomes is negatively regulated by PKA phosphorylation. Dual color fluorescence cross-correlation spectroscopy reveals local AQP2 interaction with G-actin in live epithelial cells at single-molecule resolution. Cyclic adenosine monophosphate signaling and AQP2 phosphorylation release AQP2 from G-actin. In turn, AQP2 phosphorylation increases its affinity to TM5b, resulting in reduction of TM5b bound to F-actin, subsequently inducing F-actin destabilization. RNA interference–mediated knockdown and overexpression of TM5b confirm its inhibitory role in apical trafficking of AQP2. These findings indicate a novel mechanism of channel protein trafficking, in which the channel protein itself critically regulates local actin reorganization to initiate its movement.
Bat3 deficiency accelerates the degradation of Hsp70-2/HspA2 during spermatogenesis
Authors: Sasaki Toru , Marcon Edyta , McQuire Tracy , Arai Yoichi , Moens Peter B. , Okada Hitoshi
Published: August 2008

Meiosis is critical for sexual reproduction. During meiosis, the dynamics and integrity of homologous chromosomes are tightly regulated. The genetic and molecular mechanisms governing these processes in vivo, however, remain largely unknown. In this study, we demonstrate that Bat3/Scythe is essential for survival and maintenance of male germ cells (GCs). Targeted inactivation of Bat3/Scythe in mice results in widespread apoptosis of meiotic male GCs and complete male infertility. Pachytene spermatocytes exhibit abnormal assembly and disassembly of synaptonemal complexes as demonstrated by abnormal SYCP3 staining and sustained γ-H2AX and Rad51/replication protein A foci. Further investigation revealed that a testis-specific protein, Hsp70-2/HspA2, is absent in Bat3-deficient male GCs at any stage of spermatogenesis; however, Hsp70-2 transcripts are expressed at normal levels. We found that Bat3 deficiency induces polyubiquitylation and subsequent degradation of Hsp70-2. Inhibition of proteasomal degradation restores Hsp70-2 protein levels. Our findings identify Bat3 as a critical regulator of Hsp70-2 in spermatogenesis, thereby providing a possible molecular target in idiopathic male infertility.
FGF-23–Klotho signaling stimulates proliferation and prevents vitamin D–induced apoptosis
Authors: Medici Damian , Razzaque Mohammed S. , DeLuca Stephelynn , Rector Trent L. , Hou Bo , Kang Kihwa , Goetz Regina , Mohammadi Moosa , Kuro-o Makoto , Olsen Bjorn R. , Lanske Beate
Published: August 2008

Fibroblast growth factor 23 (FGF-23) and Klotho are secretory proteins that regulate mineral-ion metabolism. Fgf-23−/− or Klotho−/− knockout mice exhibit several pathophysiological processes consistent with premature aging including severe atrophy of tissues. We show that the signal transduction pathways initiated by FGF-23–Klotho prevent tissue atrophy by stimulating proliferation and preventing apoptosis caused by excessive systemic vitamin D. Because serum levels of active vitamin D are greatly increased upon genetic ablation of Fgf-23 or Klotho, we find that these molecules have a dual role in suppression of apoptotic actions of vitamin D through both negative regulation of 1α-hydroxylase expression and phosphoinositide-3 kinase–dependent inhibition of caspase activity. These data provide new insights into the physiological roles of FGF-23 and Klotho.
Dynamic partitioning of mitotic kinesin-5 cross-linkers between microtubule-bound and freely diffusing states
Authors: Cheerambathur Dhanya K. , Brust-Mascher Ingrid , Civelekoglu-Scholey Gul , Scholey Jonathan M.
Published: August 2008

The dynamic behavior of homotetrameric kinesin-5 during mitosis is poorly understood. Kinesin-5 may function only by binding, cross-linking, and sliding adjacent spindle microtubules (MTs), or, alternatively, it may bind to a stable “spindle matrix” to generate mitotic movements. We created transgenic Drosophila melanogaster expressing fluorescent kinesin-5, KLP61F-GFP, in a klp61f mutant background, where it rescues mitosis and viability. KLP61F-GFP localizes to interpolar MT bundles, half spindles, and asters, and is enriched around spindle poles. In fluorescence recovery after photobleaching experiments, KLP61F-GFP displays dynamic mobility similar to tubulin, which is inconsistent with a substantial static pool of kinesin-5. The data conform to a reaction–diffusion model in which most KLP61F is bound to spindle MTs, with the remainder diffusing freely. KLP61F appears to transiently bind MTs, moving short distances along them before detaching. Thus, kinesin-5 motors can function by cross-linking and sliding adjacent spindle MTs without the need for a static spindle matrix.
Ticks produce highly selective chemokine binding proteins with antiinflammatory activity
Authors: Déruaz Maud , Frauenschuh Achim , Alessandri Ana L. , Dias João M. , Coelho Fernanda M. , Russo Remo C. , Ferreira Beatriz R. , Graham Gerard J. , Shaw Jeffrey P. , Wells Timothy N.C. , Teixeira Mauro M. , Power Christine A. , Proudfoot Amanda E.I.
Published: August 2008

Bloodsucking parasites such as ticks have evolved a wide variety of immunomodulatory proteins that are secreted in their saliva, allowing them to feed for long periods of time without being detected by the host immune system. One possible strategy used by ticks to evade the host immune response is to produce proteins that selectively bind and neutralize the chemokines that normally recruit cells of the innate immune system that protect the host from parasites. We have identified distinct cDNAs encoding novel chemokine binding proteins (CHPBs), which we have termed Evasins, using an expression cloning approach. These CHBPs have unusually stringent chemokine selectivity, differentiating them from broader spectrum viral CHBPs. Evasin-1 binds to CCL3, CCL4, and CCL18; Evasin-3 binds to CXCL8 and CXCL1; and Evasin-4 binds to CCL5 and CCL11. We report the characterization of Evasin-1 and -3, which are unrelated in primary sequence and tertiary structure, and reveal novel folds. Administration of recombinant Evasin-1 and -3 in animal models of disease demonstrates that they have potent antiinflammatory properties. These novel CHBPs designed by nature are even smaller than the recently described single-domain antibodies (Hollinger, P., and P.J. Hudson. 2005. Nat. Biotechnol. 23:1126–1136), and may be therapeutically useful as novel antiinflammatory agents in the future.
AID expression levels determine the extent of cMyc oncogenic translocations and the incidence of B cell tumor development
Authors: Takizawa Makiko , Tolarová Helena , Li Zhiyu , Dubois Wendy , Lim Susan , Callen Elsa , Franco Sonia , Mosaico Maria , Feigenbaum Lionel , Alt Frederick W. , Nussenzweig André , Potter Michael , Casellas Rafael
Published: August 2008

Immunoglobulin (Ig) isotype switching is a recombination event that changes the constant domain of antibody genes and is catalyzed by activation-induced cytidine deaminase (AID). Upon recruitment to Ig genes, AID deaminates cytidines at switch (S) recombination sites, leading to the formation of DNA breaks. In addition to their role in isotype switching, AID-induced lesions promote Igh-cMyc chromosomal translocations and tumor development. However, cMyc translocations are also present in lymphocytes from healthy humans and mice, and thus, it remains unclear whether AID directly contributes to the dynamics of B cell transformation. Using a plasmacytoma mouse model, we show that AID+/− mice have reduced AID expression levels and display haploinsufficiency both in the context of isotype switching and plasmacytomagenesis. At the Ig loci, AID+/− lymphocytes show impaired intra- and inter-switch recombination, and a substantial decrease in the frequency of S mutations and chromosomal breaks. In AID+/− mice, these defects correlate with a marked decrease in the accumulation of B cell clones carrying Igh-cMyc translocations during tumor latency. These results thus provide a causality link between the extent of AID enzymatic activity, the number of emerging Igh-cMyc–translocated cells, and the incidence of B cell transformation.
Rates of Clostridium difficile Infection in Patients Discharged From Spanish Hospitals, 1997-2005
Authors: Soler Pilar , Nogareda Francisco , Cano Rosa
Published: August 2008

We analyzed the Spanish hospital discharges registered from 1997 to 2005 with patient diagnoses of “intestinal infection due to Clostridium difficile.” The mean annual incidence rate was 41.2 diagnoses per 100,000 discharges. A significant increase was found from 1997 to 2005 (slope of the regression line [b], 5.12; P < .001). Overall rates were 2.5 times as high in the group of patients aged at least 65 years as in the group aged 45-64 years.
Powerful fusion: PSI-BLAST and consensus sequences
Authors: Przybylski Dariusz , Rost Burkhard
Published: August 2008

Motivation: A typical PSI-BLAST search consists of iterative scanning and alignment of a large sequence database during which a scoring profile is progressively built and refined. Such a profile can also be stored and used to search against a different database of sequences. Using it to search against a database of consensus rather than native sequences is a simple add-on that boosts performance surprisingly well. The improvement comes at a price: we hypothesized that random alignment score statistics would differ between native and consensus sequences. Thus PSI-BLAST-based profile searches against consensus sequences might incorrectly estimate statistical significance of alignment scores. In addition, iterative searches against consensus databases may fail. Here, we addressed these challenges in an attempt to harness the full power of the combination of PSI-BLAST and consensus sequences.

Results: We studied alignment score statistics for various types of consensus sequences. In general, the score distribution parameters of profile-based consensus sequence alignments differed significantly from those derived for the native sequences. PSI-BLAST partially compensated for the parameter variation. We have identified a protocol for building specialized consensus sequences that significantly improved search sensitivity and preserved score distribution parameters. As a result, PSI-BLAST profiles can be used to search specialized consensus sequences without sacrificing estimates of statistical significance. We also provided results indicating that iterative PSI-BLAST searches against consensus sequences could work very well. Overall, we showed how a very popular and effective method could be used to identify significantly more relevant similarities among protein sequences.

Availability:  http://www.rostlab.org/services/consensus/

Contact:  dariusz@mit.edu
Model-based prediction of sequence alignment quality
Authors: Ahola Virpi , Aittokallio Tero , Vihinen Mauno , Uusipaikka Esa
Published: August 2008

Motivation: Multiple sequence alignment (MSA) is an essential prerequisite for many sequence analysis methods and valuable tool itself for describing relationships between protein sequences. Since the success of the sequence analysis is highly dependent on the reliability of alignments, measures for assessing the quality of alignments are highly requisite.

Results: We present a statistical model-based alignment quality score. Unlike other quality scores, it does not require several parallel alignments for the same set of sequences or additional structural information. Our quality score is based on measuring the conservation level of reference alignments in Homstrad. Reference sequences were realigned with the Mafft, Muscle and Probcons alignment programs, and a sum-of-pairs (SP) score was used to measure the quality of the realignments. Statistical modelling of the SP score as a function of conservation level and other alignment characteristics makes it possible to predict the SP score for any global MSA. The predicted SP scores are highly correlated with the correct SP scores, when tested on the Homstrad and SABmark databases. The results are comparable to that of multiple overlap score (MOS) and better than those of normalized mean distance (NorMD) and normalized iRMSD (NiRMSD) alignment quality criteria. Furthermore, the predicted SP score is able to detect alignments with badly aligned or unrelated sequences.

Availability: The method is freely available at http://www.mtt.fi/AlignmentQuality/

Contact:  virpi.ahola@mtt.fi

Supplementary information:  Supplementary data are available at Bioinformatics online.
3-Hydroxyadamantane-1-acetic acid
Authors: Geng Xiao-Hong , Kong Li-Chun , Feng Yun-Long
Published: August 2008

The crystal structure of the title adamantane derivative, C12H18O3, has been determined by X-ray diffraction. The structure is stabilized by intermolecular O—H...O hydrogen bonds, forming a chain.
(5,10,15,20-Tetraphenylporphyrinato-κ4
N)(2,2,2-trifluoro-1-phenylethylidene-κC
1)ruthenium(II): a stable fluorinated alkylidene complex of a ruthenium(II) porphyrin
Authors: Yuge Hidetaka , Arakawa Natsuko , Wada Satoko , Miyamoto Takeshi Ken
Published: August 2008

In the title compound, [Ru(C44H28N4)(C8H5F3)], the fluorinated alkylidene group is bound to a five-coordinate Ru atom, which is located toward the carbene C atom, 0.3301 (5)Å from the least-squares plane of the C20N4 porphyrin core. The Ru=C bond is tilted slightly from the normal to the C20N4 least-squares plane due to steric repulsion between the porphyrinate ligand and the bulky trifluoromethyl group. The Ru=C bond length of 1.838 (2) Å is comparable with those in bis(subsituted phenyl)carbene analogs.
4,4′-[8b,8c-Bis(ethoxycarbonyl)-4,8-dioxo-2,3,5,6-tetrahydro-1H,4H-2,3a,4a,6,7a,8a-hexaazacyclopenta[def]fluorene-2,6-diyl]dipyridinium bis(tetrafluoridoborate)
Authors: Qin Shu-Qi , Pang Tao , Li Yi-Tao
Published: August 2008

In the title compound, C26H32N8O6
2+·2BF4
−, the cation is built up from four fused rings, viz. two nearly planar imidazole rings and two triazine rings exhibiting chair conformations. One ethoxy group is disordered between two positions in an approximate ratio 3:2. The F atoms of the two anions are each rotationally disordered between two orientations in the same 3:2 ratio. The crystal structure is stabilized by intermolecular N—H...O, C—H...F and N—H...F interactions.
4,4′-Dimethoxy-2,2′-[1,1′-(propane-1,3-diyldinitrilo)diethylidyne]diphenol
Authors: Fun Hoong-Kun , Kia Reza
Published: August 2008

In the crystal structure, the title Schiff base compound, C21H26N2O4, has twofold rotation symmetry. The imino group is coplanar with the aromatic ring. An intramolecular O—H...N hydrogen bond forms a six- membered ring, producing an S(6) ring motif. The two benzene rings are almost perpendicular to each other, making a dihedral angle of 85.00 (2)°. The methoxy group is approximately coplanar with the benzene ring, with a C—O—C—C torsion angle of 2.34 (12)°. Neighbouring molecules are linked together by weak intermolecular C—H...O hydrogen bonds and a C—H...π interaction, forming a sheet parallel to the ab plane. The molecules also adopt a zigzag arrangement along the c axis.
Acetoguanamine N,N-dimethylformamide solvate
Authors: Portalone Gustavo
Published: August 2008

The structure of acetoguanamine (or 2,4-diamino-6-methyl-1,3,5-triazine) has been determined as the N,N-dimethylformamide solvate, C4H7N5·C3H7NO. The molecular components are associated in the crystal structure to form ribbons stabilized by three N—H...N and one N—H...O hydrogen bonds which involve NH groups as donors and the N atoms of the heterocyclic ring and the carbonyl O atom of the solvent as acceptors.
trans-Tetraiodidobis(tri-p-tolylphosphine oxide-κO)tin(IV)
Authors: Hitosugi-Levesque Marina , Tanski Joseph M.
Published: August 2008

The centrosymmetric title compound, [SnI4(C21H21OP)2], is a monomeric complex that displays a nearly octahedral coordination of tin(IV), with an Sn—O bond distance of 2.159 (2) Å and an average Sn—I bond distance of 2.79 (3) Å.
[μ-2,8-Dimethyl-1,4,5,6,7,10,11,12-octahydrodiimidazo[4,5-h;4′,5′-c][1,6]diazecine-5,11-diacetato]bis[diaquanitratocopper(II)] trihydrate
Authors: Luna-Ramírez Karen S. , Bernès Sylvain , Gasque Laura
Published: August 2008

The title compound, [Cu2(C16H20N6O4)(NO3)2(H2O)4]·3H2O, crystallizes with two dinuclear CuII complex molecules, each lying on an inversion center, and six solvent water molecules per unit cell. The central 1,6-diazecine ring adopts the common chair conformation invariably found in the family of complexes bearing such ligands. The CuII atoms have an octahedral geometry, with a very strong tetragonal distortion due to the Jahn–Teller effect. Axial sites are occupied by a nitrate ion and a water molecule. The Cu...Cu separations [7.3580 (9) and 7.3341 (9) Å] are compatible with a potential catecholase activity. Neighboring molecules in the crystal structure are connected via O—H...O hydrogen bonds formed by water molecules and carboxylate O atoms. N—H...O hydrogen bonds are also present.
1,5-Bis(4-bromophenyl)-3-phenylpentane-1,5-dione
Authors: Li Kao-Zhen , Chen Yu-Ting , Zhao Chuan-Wen , Wei Guo-Dong , He Qing-Peng
Published: August 2008

The asymmetric unit of the title compound, C23H18Br2O2, contains two independent molecules with slightly different conformations. In the absence of classical intermolecular interactions, the crystal packing is stabilized by van der Waals forces.
Poly[aqua[μ2-1,1′-(butane-1,4-diyl)diimidazole](μ2-naphthalene-1,4-dicarboxylato)nickel(II)]
Authors: Zou Xian-Zhi
Published: August 2008

In the title compound, [Ni(C12H6O4)(C10H14N4)(H2O)]
n
, the coordination polyhedron around each NiII atom is a distorted cis-NiN2O4 octahedron. The naphthalene-1,4-dicarboxylate and 1,1′-(butane-1,4-diyl)diimidazole ligands bridge the Ni centres to form a two-dimensional (4,4)-network, and O—H...O hydrogen bonds complete the structure.
6-[(Dimethylamino)methyleneamino]-1,3-dimethylpyrimidine-2,4(1H,3H)-dione dihydrate
Authors: Das Subrata , Saikia Binoy K. , Sridhar B. , Thakur Ashim J.
Published: August 2008

Uracil, the pyrimidine nucleobase, which combined with adenine forms one of the major motifs present in the biopolymer RNA, is also involved in the self-assembly of RNA. In the title compound, C9H14N4O2·2H2O, the asymmetric unit contains one dimethylaminouracil group and two water molecules. The plane of the N=C—NMe2 side chain is inclined at 27.6 (5)° to the plane of the uracil ring. Both water molecules form O—H...O hydrogen bonds with the carbonyl O atoms of the uracil group. Additional water–water hydrogen-bond interactions are also observed in the crystal structure. The O—H...O hydrogen bonds lead to the formation of a two-dimensional hydrogen-bonded network cage consisting of two dimethylaminouracil groups and six water molecules.
4,4-Difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene
Authors: Xu Hai-Jun
Published: August 2008

In the title compound, C13H15BF2N2, the two pyrrole rings are almost coplanar, with a dihedral angle of 3.08 (10)°. The BF2 plane is almost perpendicular to the boron–dipyrromethene ring plane, with a dihedral angle of 89.99 (7)°.
2-(2,5-Dioxotetrahydrofuran-3-yl)isoindoline-1,3-dione
Authors: Qian Shao-Song
Published: August 2008

In the title compound, C12H7NO5, the dihedral angle between the isoindole-1,3-dione plane and the least-squares plane of the furan ring is 89.2 (2)°. In the crystal structure, molecules are linked through intermolecular C—H...O hydrogen bonds, forming centrosymmetric dimers.
1-(o-Tolyl)thiourea
Authors: Corrêa Rodrigo S. , Ribeiro Leandro , Ellena Javier , Estévez-Hernández Osvaldo , Duque Julio
Published: August 2008

In the title compound, C8H10N2S, the o-tolyl group and the thiourea core are planar. The mean planes of the two groups are almost perpendicular [82.19 (8)°]. The thiourea group is in the thioamide form, in which resonance is present. In the crystal structure, molecules are linked by intermolecular N—H...S hydrogen bonds, forming two infinite chains parallel to the (110) and (1\overline{1}0) planes.
catena-Poly[[μ-bromido-(μ-hydroxydi-2-pyridylmethanolato-κ4
N,O:O,N′)dicopper(II)(Cu—Cu)]-di-μ-bromido]
Authors: Zeller Matthias , Westcott Barry L. , Kopp-Vaughn Kristin M. , Hunter Allen D.
Published: August 2008

The title complex, [Cu2Br3(C11H9N2O2)]
n
, was one of three isolated by slow evaporation of an acetonitrile reaction mixture of CuBr2 with di-2-pyridyl ketone (1:1 molar ratio). The title complex contains a 2:1 metal-to-ligand ratio of copper(II) with the hydrated form of the ligand, di-2-pyridylmethanediol. The two copper centers are bridged by a bromide ion and the alkoxy O atom, and the Cu—Cu distance is 2.9801 (5) Å. The dimeric units are further linked by bromide ions, leading to a two-dimensional extended bridged structure. O—H...O hydrogen bonds are present in the crystal structure.
Quinazoline-2,4(1H,3H)-dione
Authors: Liu Ge
Published: August 2008

In the title compound, C8H6N2O2, intermolecular N—H...O hydrogen bonds involving the amine and carbonyl groups create centrosymmetric dimers between adjacent nearly coplanar molecules. These dimers are further connected by weak N—H...O hydrogen bonds, forming a two-dimensional network. Molecules are packed in the crystal structure with adjacent benzene and pyrimidine rings approximately coplanar; the centroid–centroid separation is 3.863 Å and the dihedral angle between the mean planes is 0.64°, indicating the presence of weak intermolecular face-to-face π–π stacking interactions.
(E)-Methyl N′-[1-(4-methoxyphenyl)ethylidene]hydrazinecarboxylate
Authors: Lv Lu-Ping , Yu Wei-Ping , Yu Wen-Bo , Zhou Xue-Feng , Hu Xian-Chao
Published: August 2008

The molecule of the title compound, C11H14N2O3, adopts a trans configuration with respect to the C=N bond. The dihedral angle between the benzene ring and the hydrazinecarboxylate plane is 12.06 (9)°. Molecules are linked into a one-dimensional network by N—H...O hydrogen bonds and C—H...π interactions. The benzene rings of inversion-related molecules are stacked with their centroids separated by 3.777 (1) Å, indicating π–π interactions.
{4,4′,5,5′-Tetramethyl-2,2′-[1,1′-(ethane-1,2-diyldinitrilo)diethylidyne]diphenolato}nickel(II)–methanol–chloroform (1/1/1)
Authors: Fun Hoong-Kun , Kia Reza
Published: August 2008

In the title compound, [Ni(C22H26N2O2)]·CH3OH·CHCl3, the NiII ion is in a slightly distorted square-planar geometry involving an N2O2 atom set of the tetradentate Schiff base ligand. The asymmetric unit contains one molecule of the complex and one molecule each of chloroform and methanol. The methanol molecule is hydrogen bonded to the phenolate O atoms. In the crystal structure, short intermolecular distances between the centroids of six-membered chelate rings [3.7002 (9) Å] indicate the presence of π–π interactions, which link the molecules into stacks along the a axis. In addition, there are Ni...Ni distances which are shorter than the sum of the van der Waals radii of two Ni atoms. The crystal structure is further stabilized by intermolecular O—H...O and C—H...O hydrogen bonds, and weak intermolecular C—H...π interactions linking molecules into extended one-dimensional chains along the c axis.
9-Ethyl-2,3-dihydro-9H-carbazol-4(1H)-one
Authors: Murugavel S. , Ganesh G. , Pandi A. Subbiah , Murugan Ramalingam , Narayanan S. Sriman
Published: August 2008

In the title compound, C28H30N2O2, the cyclohexene ring system adopts a sofa conformation. The crystal structure is stabilized by C—H...O interactions between methyl H atoms of the ethyl substituents and the O atoms of carbonyl groups of adjacent molecules, and by an intermolecular carbonyl–carbonyl interactions [3.207 (2) Å]
3-(4-Fluorophenyl)-2-(4-methoxyphenoxy)-4-oxo-5-phenyl-4,5-dihydro-3H-pyrrolo[3,2-d]pyrimidine-7-carbonitrile
Authors: Zeng Guo-Ping , Yan Shi-Rong
Published: August 2008

There are two crystallographically independent molecules in the asymmetric unit of the title compound, C26H17FN4O3, which differ in the dihedral angles between the aromatic rings (fluorophenyl, phenyl) and the pyrrolopyrimidine rings [0.6 (3)/76.3° and 73.7 (3)/64.6°, respectively]. The crystal structure is mainly stabilized by C—H...O and C—H...F interactions.
Bis{[(η5)-cyclopentadienyl]tris(diethyl phosphito-κ3
P,P′,P′′)cobaltate(III)-κ3
O,O′,O′′]oxovanadium(IV)}-μ-oxalate
Authors: McLauchlan Craig C. , Anderson Alexander E.
Published: August 2008

The title compound {systematic name: bis[1,4(η5)-cyclopentadienyl]hexakis(μ-diethyl phosphito)-1:2κ6
P:O;3:4κ6
O:P-μ-oxalato-2:3κ4
O
1,O
2:O
1′,O
2′-dioxido-2κO,3κO-1,4-dicobalt(III)-2,3-divanadium(IV)}, [Co2V2(C5H5)2(C2O4)(C4H10O3P)6O2], is an oxalate-bridged dinuclear complex of oxovanadium(IV). The geometric center of the dimer lies on an inversion center. The unique Co atom is bonded to three P atoms and a cyclopentadienyl ring. The unique V atom has six O atom neighbors in an approximately octahedral arrangement; the V—O bond trans to the V=O bond is significantly lengthened.
4-Chloro-N′-[(Z)-4-nitrobenzylidene]benzohydrazide monohydrate
Authors: Fun Hoong-Kun , Patil P. S. , Rao Jyothi N. , Kalluraya B. , Chantrapromma Suchada
Published: August 2008

In the title compound, C14H10ClN3O3·H2O, the benzohydrazide group is not planar and the molecule exists in a cis configuration with respect to the methylidene unit. The dihedral angle between the two substituted benzene rings is 38.7 (3)°. In the crystal structure, molecules are linked by O—H...O, O—H...N and N—H...O hydrogen bonds into a two-dimensional network parallel to the (100) plane. The crystal structure is further stabilized by weak C—H...O interactions.
N′-(2-Hydroxybenzylidene)-2-methoxybenzohydrazide monohydrate
Authors: Lu Jiu-Fu , Min Suo-Tian , Ji Xiao-Hui , Dang Zhong-Hai
Published: August 2008

In the title compound, C15H14N2O3·H2O, the Schiff base molecule is approximately planar, with a dihedral angle between the two aromatic rings of 10.2 (3)°. The molecular structure is stabilized by O—H...N and N—H...O hydrogen bonds. In the crystal structure, the Schiff base and water molecules are linked together by intermolecular O—H...O hydrogen bonds, forming chains parallel to the a axis.
trans-4-[(Phenylsulfonyloxy)methyl]cyclohexanecarboxylic acid
Authors: Liang Yu-Feng , Qi Qing-Rong , Zheng Hu
Published: August 2008

The title compound, C14H18O5S, is an important intermediate for the synthesis of poly(amidoamine) dendrimers. The cyclohexane ring adopts a chair conformation with its two substituents in equatorial positions. In the crystal structure, molecules form centrosymmetric dimers via O—H...O hydrogen bonds.
The cocrystal μ-oxalato-κ4
O
1,O
2:O
1′,O
2′-bis(aqua(nitrato-κO){[1-(2-pyridyl-κN)ethylidene]hydrazine-κN}copper(II)) μ-oxalato-κ4
O
1,O
2:O
1′,O
2′-bis((methanol-κO)(nitrato-κO){[1-(2-pyridyl-κN)ethylidene]hydrazine-κN}copper(II)) (1/1)
Authors: Diallo Madina , Tamboura Farba Bouyagui , Gaye Mohamed , Barry Aliou Hamady , Bah Youssouph
Published: August 2008

The title cocrystal, [Cu2(C2O4)(NO3)2(C7H9N3)2(H2O)2][Cu2(C2O4)(NO3)2(C7H9N3)2(CH4O)2], is a 1:1 cocrystal of two centrosymmetric CuII complexes with oxalate dianions and Schiff base ligands. In each molecule, the CuII centre is in a distorted octahedral cis-CuN2O4 environment, the donor atoms of the N,N′-bidentate Schiff base ligand and the bridging O,O′-bidentate oxalate group lying in the equatorial plane. In one molecule, a monodentate nitrate anion and a water molecule occupy the axial sites, and in the other, a monodentate nitrate anion and a methanol molecule occupy these sites. In the crystal structure, intermolecular N—H...O, O—H...O and N—H...N hydrogen bonds link the molecules into a network. Weak intramolecular N—H...O interactions are also observed.
N-(2-Methylphenyl)benzenesulfonamide
Authors: Gowda B. Thimme , Foro Sabine , Babitha K. S. , Fuess Hartmut
Published: August 2008

In the title compound, C13H13NO2S, the conformation of the N—H bond is anti to the ortho-methyl group on the aniline ring, in contrast to the syn conformation observed with respect to the ortho-chloro group in N-(2-chlorophenyl)benzenesulfonamide. The dihedral angle between the two benzene rings is 61.5 (1)°. Molecules are linked into chains running along the a axis by N—H...O hydrogen bonds.
1-Deoxy-L-mannitol (6-deoxy-L-mannitol or L-rhamnitol)
Authors: Jenkinson Sarah F. , Booth K. Victoria , Gullapalli Pushpakiran , Morimoto Kenji , Izumori Ken , Fleet George W. J. , Watkin David J.
Published: August 2008

The crystalline form of 1-deoxy-L-mannitol, C6H14O5, exists as an extensively hydrogen-bonded structure with each molecule acting as a donor and acceptor for five hydrogen bonds. There are no unusual crystal-packing features; the absolute configuration was determined from the use of 6-deoxy-L-mannose (L-rhamnose) as the starting material.
3-(5,6,7,8-Tetrahydro-2-naphthyl)isobenzofuran-1(3H)-one
Authors: Kitamura Chitoshi , Kawase Takeshi
Published: August 2008

The title compound, C18H16O2, was prepared by reduction of 2-(5,6,7,8-tetrahydro-2-naphthoyl)benzoic acid with zinc dust. The benzene ring in the tetrahydronaphthyl substituent is nearly perpendicular to the plane of the isobenzofuran-1(3H)-one ring [87.15 (4)°]. The cyclohexane unit has a half-chair conformation in which two methylene groups in the tetramethylene bridge are disordered over two positions; the site-occupancy factors are 0.838 (4) and 0.162 (4). The crystal structure exhibits alternating isobenzofuran-1(3H)-one and tetrahydronaphthalene layers.
3,5-Dinitropyridin-4(1H)-one monohydrate
Authors: Li Ying , Li Ping , Zhou Qiu-Ping , Zhang Guo-Fang , Ng Seik Weng
Published: August 2008

The three independent organic molecules of 3,5-dinitropyridin-4(1H)-one monohydrate, C5H3N3O5·H2O, each feature an N—H...Owater hydrogen bond. Each water molecule serves as hydrogen-bond donor to two carbonyl O atoms; these hydrogen bonds give rise to a layer motif. Two of the three formula units lie on special positions of site symmetry 2.
N-(2,6-Dimethylphenyl)benzenesulfonamide
Authors: Gowda B. Thimme , Foro Sabine , Babitha K. S. , Fuess Hartmut
Published: August 2008

In the crystal structure of the title compound, C14H15NO2S, the N—H bond is trans to one of the S=O double bonds, similar to what is observed in N-(2-methylphenyl)benzenesulfonamide and other aryl sulfonamides. The two aromatic rings enclose a dihedral angle of 44.9 (1)°. The molecules are connected by intermolecular N—H...O hydrogen bonds into chains running along the a axis. An intermolecular C—H...O hydrogen bond is also present.
(2,2-Bipyridyl)bis(η5-pentamethylcyclopentadienyl)strontium(II)
Authors: Kazhdan Daniel , Hu Yung-Jin , Kokai Akos , Levi Zerubba , Rozenel Sergio
Published: August 2008

In the title compound, [Sr(C10H15)2(C10H8N2)], the Sr—N distances are 2.624 (3) and 2.676 (3) Å, the Sr...Cp ring centroid distances are 2.571 and 2.561 Å and the N—C—C—N torsion angle in the bipyridine ligand is −2.2 (4)°. Interestingly, the bipyridine ligand is tilted. The angle between the plane defined by the Sr atom and the two bipyridyl N atoms and the plane defined by the 12 atoms of the bipyridine ligand is 10.7 (1)°.
Methyl 2-(5-methyl-3-methylsulfinyl-1-benzofuran-2-yl)acetate
Authors: Choi Hong Dae , Seo Pil Ja , Son Byeng Wha , Lee Uk
Published: August 2008

The title compound, C13H14O4S, was prepared by oxidation of methyl 2-(5-methyl-3-methylsulfanyl-1-benzofuran-2-yl)acetate with 3-chloroperoxybenzoic acid. The O atom and methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran system. The crystal structure is stabilized by intermolecular aromatic π–π interactions between the benzene rings of neighbouring molecules, with a centroid–centroid separation of 3.841 (3) Å.
2,4-Bis(3-fluorophenyl)-3-azabicyclo[3.3.1]nonan-9-one
Authors: Parthiban P. , Thirumurugan K. , Ramkumar V. , Pazhamalai S. , Jeong Yeon Tae
Published: August 2008

The title compound, C20H19F2NO, exhibits a chair–chair conformation, with the aryl groups in the heterocycle in equatorial orientations and oriented at an angle of 33.35 (3)° to one another. A crystallographic mirror plane, passing through the N atom, the C and O atoms of the carbonyl group and the C atom in the 7-position, bisects the molecule. The molecular structure is stabilized by one C—H...N interaction and the crystal structure is stabilized by a weak C—H...π interaction.
catena-Poly[[diaqua[(4-tolylsulfanyl)acetato-κO]cadmium(II)]-μ-4,4′-bipyridine-κ2
N:N′]
Authors: Cai Wen-Xuan , Zheng Xiao-Yong , Geng Xiao-Hong , Feng Yun-Long
Published: August 2008

The title complex, [Cd(C9H9O2S)2(C10H8N2)(H2O)2]
n
, has a linear chain structure. The central CdII ion is in a slightly disorted octahedral environment, coordinated by two aqua ligands, two (4-tolylsulfanyl)acetate ligands and two bridging 4,4′-bipyridine ligands. The CdII ion lies on a twofold rotation axis. Intermolecular O—H...O hydrogen bonds connect adjacent chains, forming a layer structure. An intramolecular O—H...O hydrogen bond is also present.
2,4-Bis(4-fluorophenyl)-3-azabicyclo[3.3.1]nonan-9-one
Authors: Parthiban P. , Ramkumar V. , Santan H. D. , Kim Jong Tae , Jeong Yeon Tae
Published: August 2008

In the title compound, C20H19F2NO, a crystallographic mirror plane bisects the molecule, passing through the N, O and two C atoms of the central ring system. The molecule exists in a twin-chair conformation with equatorial dispositions of the 4-fluorophenyl groups on both sides of the secondary amino groups; the dihedral angle between the aromatic ring planes is 28.67 (3)°.
Hexaaquazinc(II) dichloride bis(hexamethylenetetramine) tetrahydrate
Authors: Yao Xin Jian , Xuan Ya Wen , Wu Wen
Published: August 2008

The title compound, [Zn(H2O)6]Cl2·2C6H12N4·4H2O, has been prepared under mild hydrothermal conditions. The ZnII atom, located on a centre of symmetry, is coordinated by six water molecules in a distorted octahedral coordination geometry. The hexamethylenetetramine molecule is not coordinated to ZnII but links the Zn complexes via three O—H...N hydrogen bonds. The remaining N atom of the hexamethylenetetramine molecule is hydrogen-bonded to a solvent water molecule. In the crystal structure, intermolecular O—H...O, O—H...N and O—H...Cl hydrogen bonds link the components into a three-dimensional network.
Benzene-1,3-diacetic acid
Authors: Zhu Mei
Published: August 2008

Molecules of the title compound, C10H10O4, are connected through O—H...O hydrogen-bonding interactions into chains running along the c axis.
2-Methoxy-N′-(2-methoxybenzylidene)benzohydrazide
Authors: Lu Jiu-Fu , Min Suo-Tian , Ji Xiao-Hui , Dang Zhong-Hai
Published: August 2008

The title Schiff base compound, C16H16N2O3, was derived from the condensation of 2-methoxybenzaldehyde with 2-methoxybenzohydrazide in an ethanol solution. The dihedral angle between the two aromatic rings is 87.5 (3)°. In the crystal structure, the molecules are linked into chains running parallel to the a axis by intermolecular N—H...O hydrogen bonds.
The influence of protected area management on the status of coral reefs at Misali Island, Tanzania following the 1998 bleaching event in the western Indian Ocean
Authors: Poonian C. N. S.
Published: August 2008

The reefs of Misali Island, Tanzania suffered serious coral mortality as a result of the 1998 coral bleaching event in the western Indian Ocean. Four years after this event, Frontier‐Tanzania assessed reef substrate in Misali Island Marine Conservation Area (MIMCA) using scuba surveys. Substrate cover was compared between sites within and outside the nonextraction zone (NEZ) of MIMCA and recovery rates were estimated through reference to previous studies. Coral recovery at Misali Island following the bleaching event has generally been slow, but nonextractive management of MIMCA has enhanced coral recovery within the NEZ. The absence of fishing activities in the NEZ has sustained herbivorous fish populations and thus reduced algal overgrowth; however, outside the NEZ, diving and anchoring activities have caused further coral damage and led to increased levels of debris. Awareness‐raising programmes could lessen these problems and the NEZ appeared to be well‐placed to capitalize on nonmanageable factors that are thought to mitigate the effects of coral bleaching. In addition, the implementation of flexible zoning schemes could improve recovery rates after future bleaching events.
Shading delays bud break in Brachsyegia spiciformis
Authors: Richer R. A.
Published: August 2008

Whole tree manipulation experiments were performed in the common southern African tree species, Brachystegia spiciformis to test a novel hypothesis that decreasing Total nonstructural carbohydrates (TNC) in the stem could cause bud break in Brachystegia spiciformis. The experimental treatments included fertilization, canopy defoliation, shading and stem heating to decrease stem carbohydrates. None of the treatments significantly decreased mean stem TNC. Likewise the heating, fertilization and defoliation treatments did not significantly affect the date of bud break. However, shading significantly delayed bud break. This delay in bud break could not be attributed to changes in leaf level photosynthetic traits, stem water content, leaf predawn water potential or delayed leaf fall. These results question widely accepted hypotheses about the mechanisms controlling bud break and suggest a carbohydrate homeostatic mechanism.
Effect of shade and shading history on species abundances and ecosystem processes in temporary ponds
Authors: MOKANY A. , WOOD J. T. , CUNNINGHAM S. A.
Published: August 2008

1. The amount of sunlight that an ecosystem receives is an important determinant of primary productivity, which in turn can influence species diversity and nutrient cycling. Here, we examine the effects of shading and shading history on ecosystem processes, macroinvertebrate diversity and development of dominant ecosystem states in field‐based aquatic mesocosms.

2. We found that there were large effects of the level of shade, but few effects of shading history. Increasing light increased the biomass of filamentous algae (metaphyton) which increased the overall productivity of the ecosystem, and shifted the invertebrate community from one with more mosquitoes (filter feeders) to one with more anuran tadpoles (algal grazers).

3. There was also an effect of shading history, where increased shade led to changes in the macroinvertebrate communities that were maintained after shade was reduced in the later part of the experiment.

4. Finally, our results indicated that correlations between ecosystem processes, specific key macrofauna and the development of pond ecosystem states were greater than correlations of these factors to shading treatments. These results suggest that the history of community assembly can have a greater impact on the development of ecosystem processes than diminishing light by as much as 50%. However, light may have a potentially strong indirect effect and may impact the communities through altered bottom‐up structuring forces.
Periphyton as alternative food source for the filter‐feeding cladoceran Daphnia magna
Authors: SIEHOFF SILVANA , HAMMERS‐WIRTZ MONIKA , STRAUSS TIDO , RATTE HANS TONI
Published: August 2008

1.  Daphnia magna, a well‐studied primary consumer, is mainly known as a filter feeder. In this study, we investigated the ability of D. magna to use periphyton as an alternative food source to phytoplankton. We examined the development of laboratory populations fed with different food sources (Desmodesmus subspicatus and/or periphyton or neither) over a period of 42 days, and observed the behaviour of the daphnids.

2. The addition of periphyton to phytoplankton food led to an increase of daphnid population biomass. When fed with periphyton as the only food source, a small but stable D. magna population developed.

3. The behaviour of daphnids fed with both food sources revealed a preference for feeding on D. subspicatus. Only below a concentration of D. subspicatus of approximately 0.05 mg C L−1 (0.4 × 107 cells L−1) did D. magna use periphyton as an alternative food source.

4. Periphyton showed distinct reactions to grazing by D. magna. The thickness of the periphyton layer was reduced from about 4 to 1 mm and we observed a change in species composition due to grazing.

5. The ability of D. magna to graze on periphyton could serve to stabilize its population density and reinforce its competitive advantage over other cladocerans. By switching between food sources, D. magna can act as a coupler between pelagic and benthic habitats and food webs.
Ancient DNA applications for wildlife conservation
Authors: LEONARD JENNIFER A
Published: August 2008

Ancient DNA analyses of historical, archaeological and paleontological remains can contribute important information for the conservation of populations and species that cannot be obtained any other way. In addition to ancient DNA analyses involving a single or few individuals, population level studies are now possible. Biases inherent in estimating population parameters and history from modern genetic diversity are exaggerated when populations are small or have been heavily impacted by recent events, as is common for many endangered species. Going directly back in time to study past populations removes many of the assumptions that undermine conclusions based only on recent populations. Accurate characterization of historic population size, levels of gene flow and relationships with other populations are fundamental to developing appropriate conservation and management plans. The incorporation of ancient DNA into conservation genetics holds a lot of potential, if it is employed responsibly.
Dysregulation of the hypothalamic‐pituitary‐adrenal (HPA) axis in irritable bowel syndrome
Authors: Chang L. , Sundaresh S. , Elliott J. , Anton P. A. , Baldi P. , Licudine A. , Mayer M. , Vuong T. , Hirano M. , Naliboff B. D. , Ameen V. Z. , Mayer E. A.
Published: August 2008

Abstract Enhanced stress responsiveness has been implicated as a potential mechanism contributing to the pathophysiology of irritable bowel syndrome (IBS), and should be reflected in altered function of the hypothalamic‐pituitary‐adrenal (HPA) axis and the sympathetic nervous system. Both of these systems can modulate mucosal immune function. The aims of this study were: (i) to characterize thebasalcircadian rhythm of adrenocorticotropin hormone (ACTH) and cortisol in IBSvshealthy controls; (ii) to comparestimulatedACTH, cortisol and noradrenaline responses to a pelvic visceral stressor (sigmoidoscopy) in IBS and controls; and (iii) to correlate neuroendocrine responses with colonic mucosal cytokine expression and symptoms in IBS. Two separate studies were conducted in women. In Study 1,basalcortisol levels were analysed in 41 IBS and 25 controls using 24‐h collections of plasma ACTH and cortisol (q10 min sampling). In Study 2, 10 IBS patients with diarrhoea (IBS‐D) and 10 controls underwent sigmoidoscopy with measurements ofstimulatedneuroendocrine responses and cytokine mRNA expression in colonic tissue. Basal ACTH levels were significantly blunted (P < 0.05), while basal and stimulated plasma cortisol levels were higher in patients. Basal cortisol levels prior to an experimental visceral stressor positively correlated with anxiety symptoms (P < 0.004), but not IBS symptoms. Irritable bowel syndrome patients with diarrhoea had significantly decreased mRNA expression of mucosal cytokines [interleukin (IL)‐2, IL‐6] in the sigmoid colonvscontrols (P < 0.05). Although dysregulations in stress‐responsive systems such as the HPA axis and mucosal immune function are demonstrated in IBS, they do not appear to have a primary role in modulating IBS severity and abdominal pain.
Internal coordination between hydraulics and stomatal control in leaves
Authors: BRODRIBB TIM J. , JORDAN GREGORY J.
Published: August 2008

The stomatal response to changing leaf‐atmospheric vapour pressure gradient (Dl) is a crucial yet enigmatic process that defines the daily course of leaf gas exchange. Changes in the hydration of epidermal cells are thought to drive this response, mediated by the transpiration rate and hydraulic conductance of the leaf. Here, we examine whether species‐specific variation in the sensitivity of leaves to perturbation of Dl is related to the efficiency of water transport in the leaf (leaf hydraulic conductivity, Kleaf). We found good correlation between maximum liquid (Kleaf) and gas phase conductances (gmax) in leaves, but there was no direct correlation between normalized Dl sensitivity and Kleaf. The impact of Kleaf on Dl sensitivity in our diverse sample of eight species was important only after accounting for the strong relationship between Kleaf and gmax. Thus, the ratio of gmax/Kleaf was strongly correlated with stomatal sensitivity to Dl. This ratio is an index of the degree of hydraulic buffering of the stomata against changes in Dl, and species with high gmax relative to Kleaf were the most sensitive to Dl perturbation. Despite the potentially high adaptive significance of this phenomenon, we found no significant phylogenetic or ecological trend in our species.