bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization of agonist-sensitive PtdIns(3,4,5)P3 reveals a nuclear pool that is insensitive to PTEN expression
Authors: Lindsay Yvonne , McCoull David , Davidson Lindsay , Leslie Nick R. , Fairservice Alison , Gray Alex , Lucocq John , Downes C. Peter
Published: December 2006

Phosphatidylinositol (3,4,5) trisphosphate [PtdIns(3,4,5)P3] is a lipid second messenger, produced by Type I phosphoinositide 3-kinases (PI 3-kinases), which mediates intracellular responses to many growth factors. Although PI 3-kinases are implicated in events at both the plasma membrane and intracellular sites, including the nucleus, direct evidence for the occurrence of PtdIns(3,4,5)P3 at non-plasma membrane locations is limited. We made use of the pleckstrin homology (PH) domain of general receptor for phosphoinositides (Grp1) to detect PtdIns(3,4,5)P3 in an on-section labeling approach by quantitative immunogold electron microscopy. Swiss 3T3 cells contained low levels of PtdIns(3,4,5)P3 that increased up to 15-fold upon stimulation with platelet-derived growth factor (PDGF). The signal was sensitive to PI 3-kinase inhibitors and present mainly at plasma membranes, including lamellipodia, and in a surprisingly large pool within the nuclear matrix. Comparatively little labeling was observed in endomembranes. A similar distribution of PtdIns(3,4,5)P3 was observed in U87MG cells, which lack the PtdIns(3,4,5)P3 phosphatase, PTEN. Re-expression of PTEN into U87MG cells ablated plasma membrane PtdIns(3,4,5)P3, but not the nuclear pool of this lipid even when PTEN was targeted to nuclei. These data have important implications for the versatility of PI 3-kinase signaling and for the proposed functions of PTEN in the nucleus.
Ccr4 contributes to tolerance of replication stress through control ofCRT1mRNA poly(A) tail length
Authors: Woolstencroft Robert N. , Beilharz Traude H. , Cook Michael A. , Preiss Thomas , Durocher Daniel , Tyers Mike
Published: December 2006

In Saccharomyces cerevisiae, DNA replication stress activates the replication checkpoint, which slows S-phase progression, stabilizes slowed or stalled replication forks, and relieves inhibition of the ribonucleotide reductase (RNR) complex. To identify novel genes that promote cellular viability after replication stress, the S. cerevisiae non-essential haploid gene deletion set (4812 strains) was screened for sensitivity to the RNR inhibitor hydroxyurea (HU). Strains bearing deletions in either CCR4 or CAF1/POP2, which encode components of the cytoplasmic mRNA deadenylase complex, were particularly sensitive to HU. We found that Ccr4 cooperated with the Dun1 branch of the replication checkpoint, such that ccr4Δ dun1Δ strains exhibited irreversible hypersensitivity to HU and persistent activation of Rad53. Moreover, because ccr4Δ and chk1Δ exhibited epistasis in several genetic contexts, we infer that Ccr4 and Chk1 act in the same pathway to overcome replication stress. A counterscreen for suppressors of ccr4Δ HU sensitivity uncovered mutations in CRT1, which encodes the transcriptional repressor of the DNA-damage-induced gene regulon. Whereas Dun1 is known to inhibit Crt1 repressor activity, we found that Ccr4 regulates CRT1 mRNA poly(A) tail length and may subtly influence Crt1 protein abundance. Simultaneous overexpression of RNR2, RNR3 and RNR4 partially rescued the HU hypersensitivity of a ccr4Δ dun1Δ strain, consistent with the notion that the RNR genes are key targets of Crt1. These results implicate the coordinated regulation of Crt1 via Ccr4 and Dun1 as a crucial nodal point in the response to DNA replication stress.
Essential roles for cohesin in kinetochore and spindle function in Xenopus egg extracts
Authors: Deehan Kenney Renée , Heald Rebecca
Published: December 2006

To facilitate their accurate distribution by the mitotic spindle, sister chromatids are tethered during DNA replication, attached by their kinetochores and bi-oriented on the spindle, and then simultaneously released at the metaphase to anaphase transition, allowing for their segregation to opposite spindle poles. The highly conserved cohesin complex is fundamental to this process, yet its role in mitosis is not fully understood. We show that depletion of cohesin from Xenopus egg extracts impairs sister chromatid cohesion and kinetochore-microtubule interactions, causing defective spindle attachments and chromosome alignment during metaphase and mis-segregation during anaphase. In the absence of cohesin, sister kinetochore pairing and centromeric localization of chromosomal passenger proteins INCENP and aurora B were lost upon bipolar spindle attachment. However, kinetochores remained paired with normal passenger localization if bipolar spindle formation was prevented by inhibiting the kinesin-5 motor (Eg5). These observations indicate that cohesin is not required to establish sister association, but is necessary to maintain cohesion in the presence of bipolar spindle forces. Co-depletion of cohesin together with another major SMC complex, condensin, revealed cumulative effects on spindle assembly and chromosome architecture. These data underscore the essential requirement for cohesin in sister chromatid cohesion, kinetochore and spindle function.
Plant G protein heterotrimers require dual lipidation motifs of Gα and Gγ and do not dissociate upon activation
Authors: Adjobo-Hermans Merel J. W. , Goedhart Joachim , Gadella Theodorus W. J.
Published: December 2006

In plants one bona fide Gα subunit has been identified, as well as a single Gβ and two Gγ subunits. To study the roles of lipidation motifs in the regulation of subcellular location and heterotrimer formation in living plant cells, GFP-tagged versions of the Arabidopsis thaliana heterotrimeric G protein subunits were constructed. Mutational analysis showed that the Arabidopsis Gα subunit, GPα1, contains two lipidation motifs that were essential for plasma membrane localization. The Arabidopsis Gβ subunit, AGβ1, and the Gγ subunit, AGG1, were dependent upon each other for tethering to the plasma membrane. The second Gγ subunit, AGG2, did not require AGβ1 for localization to the plasma membrane. Like AGG1, AGG2 contains two putative lipidation motifs, both of which were necessary for membrane localization. Interaction between the subunits was studied using fluorescence resonance energy transfer (FRET) imaging by means of fluorescence lifetime imaging microscopy (FLIM). The results suggest that AGβ1 and AGG1 or AGβ1 and AGG2 can form heterodimers independent of lipidation. In addition, FLIM-FRET revealed the existence of GPα1-AGβ1-AGG1 heterotrimers at the plasma membrane. Importantly, rendering GPα1 constitutively active did not cause a FRET decrease in the heterotrimer, suggesting no dissociation upon GPα1 activation.
Integrity of all four transmembrane domains of the tetraspanin uroplakin Ib is required for its exit from the ER
Authors: Tu Liyu , Kong Xiang-Peng , Sun Tung-Tien , Kreibich Gert
Published: December 2006

The surface of the mammalian urinary bladder is covered by a crystalline, asymmetric unit membrane (AUM) structure that contains the four major uroplakins (UPs): Ia, Ib, II and IIIa. UPIa and UPIb belong to the family of tetraspanins. Although UPIa and UPIb are structurally conserved, only UPIb could exit from the endoplasmic reticulum (ER) and reach the cell surface when expressed alone in 293T cells. Modifications of the large extracellular loop of UPIb, such as mutation of the N-glycosylation site or the cysteines involved in the formation of three disulfide bridges, or exchanging the large luminal loop of UPIb with that of UPIa did not affect the ability of UPIb to reach the cell surface. However, modifications of any of the four transmembrane domains of UPIb led to ER retention, suggesting that the proper formation of helical bundles consisting of the tetraspanin transmembrane domains is a prerequisite for UPIb to exit from the ER. Results of sedimentation analysis suggested that aggregate formation is a mechanism for ER retention.
Multiple controls regulate nucleostemin partitioning between nucleolus and nucleoplasm
Authors: Meng Lingjun , Yasumoto Hiroaki , Tsai Robert Y. L.
Published: December 2006

Nucleostemin plays an essential role in maintaining the continuous proliferation of stem cells and cancer cells. The movement of nucleostemin between the nucleolus and the nucleoplasm provides a dynamic way to partition the nucleostemin protein between these two compartments. Here, we show that nucleostemin contains two nucleolus-targeting regions, the basic and the GTP-binding domains, that exhibit a short and a long nucleolar retention time, respectively. In a GTP-unbound state, the nucleolus-targeting activity of nucleostemin is blocked by a mechanism that traps its intermediate domain in the nucleoplasm. A nucleostemin-interacting protein, RSL1D1, was identified that contains a ribosomal L1-domain. RSL1D1 co-resides with nucleostemin in the same subnucleolar compartment, unlike the B23 and fibrillarin, and displays a longer nucleolar residence time than nucleostemin. It interacts with both the basic and the GTP-binding domains of nucleostemin through a non-nucleolus-targeting region. Overexpression of the nucleolus-targeting domain of RSL1D1 alone disperses nucleolar nucleostemin. Loss of RSL1D1 expression reduces the compartmental size and amount of nucleostemin in the nucleolus. Our work reveals that the partitioning of nucleostemin employs complex mechanisms involving both nucleolar and nucleoplasmic components, and provides insight into the post-translational regulation of its activity.
Outcomes of p53 activation - spoilt for choice
Authors: Vousden Karen H.
Published: December 2006

The p53 tumour suppressor protein can efficiently inhibit tumour development. This activity reflects its ability to induce a number of different responses, including cell cycle arrest and apoptosis. Recent studies have revealed some interesting insights into how the choice of response to p53 is regulated, highlighting a correlation between the activation of cell cycle arrest and survival with the ability of p53 to reduce oxidative stress and protect cells from genotoxic damage. Understanding the molecular mechanisms that determine which response is selected may allow us to modulate these pathways so that therapeutic reactivation of p53 favours apoptotic cell death in tumour cells, but a reversible - and therefore far less toxic - induction of cell cycle arrest in normal cells.
KASH-domain proteins in nuclear migration, anchorage and other processes
Authors: Wilhelmsen Kevin , Ketema Mirjam , Truong Hoa , Sonnenberg Arnoud
Published: December 2006

The nucleus in eukaryotic cells can move within the cytoplasm, and its position is crucial for many cellular events, including migration and differentiation. Nuclear anchorage and movement can be achieved through association of outer nuclear membrane (ONM) proteins with the three cytoskeletal systems. Two decades ago studies described C. elegans mutants with defects in such events, but only recently has it been shown that the strategies for nuclear positioning are indeed conserved in C. elegans, Drosophila, mammals and potentially all eukaryotes. The integral ONM proteins implicated in these processes thus far all contain a conserved Klarsicht/ANC-1/Syne homology (KASH) domain at their C-terminus that can associate with Sad1p/UNC-84 (SUN)-domain proteins of the inner nuclear membrane within the periplasmic space of the nuclear envelope (NE). The complex thus formed is responsible not only for association with cytoplasmic elements but also for the integrity of the NE itself.
Functional interaction between the ZO-1-interacting transcription factor ZONAB/DbpA and the RNA processing factor symplekin
Authors: Kavanagh Emma , Buchert Michael , Tsapara Anna , Choquet Armelle , Balda Maria S. , Hollande Frédéric , Matter Karl
Published: December 2006

Epithelial tight junctions participate in the regulation of gene expression by controlling the activity of transcription factors that can interact with junctional components. One such protein is the Y-box transcription factor ZONAB/DbpA that binds to ZO-1, a component of the junctional plaque. Symplekin, another nuclear protein that can associate with tight junctions, functions in the regulation of polyadenylation and thereby promotes gene expression. Here, we addressed the question of whether these two proteins interact and whether this is of functional relevance. We demonstrate that ZONAB/DbpA and symplekin form a complex in kidney and intestinal epithelial cells that can be immunoprecipitated and that exists in the nucleus. The interaction between ZONAB/DbpA and symplekin can be reconstituted with recombinant proteins. In reporter gene assays in which ZONAB/DbpA functions as a repressor, symplekin functionally interacts with ZONAB/DbpA, indicating that symplekin can also promote transcriptional repression. RNAi experiments indicate that symplekin depletion reduces the nuclear accumulation and the transcriptional activity of ZONAB/DbpA in colon adenocarcinoma cells, resulting in inhibition of proliferation and reduced expression of the ZONAB/DbpA-target gene cyclin D1. Our data thus indicate that symplekin and ZONAB/DbpA cooperate in the regulation of transcription, and that they promote epithelial proliferation and cyclin D1 expression.
Cadherin-2 participates in the morphogenesis of the zebrafish inner ear
Authors: Babb-Clendenon Sherry , Shen Yu-chi , Liu Qin , Turner Katharyn E. , Mills M. Susan , Cook Greg W. , Miller Caroline A. , Gattone Vincent H. , Barald Kate F. , Marrs James A.
Published: December 2006

Molecular mechanisms that control inner ear morphogenesis from the placode to the three-dimensional functional organ are not well understood. We hypothesize that cell-cell adhesion, mediated by cadherin molecules, contributes significantly to various stages of inner ear formation. Cadherin-2 (Cdh2) function during otic vesicle morphogenesis was investigated by examining morpholino antisense oligonucleotide knockdown and glass onion (glo) (Cdh2 mutant) zebrafish embryos. Placode formation, vesicle cavitation and specification occurred normally, but morphogenesis of the otic vesicle was affected by Cdh2 deficiency: semicircular canals were reduced or absent. Phalloidin staining of the hair cell stereocillia demonstrated that cadherin-2 (cdh2) loss-of-function did not affect hair cell number, but acetylated tubulin labeling showed that hair cell kinocilia were shorter and irregularly shaped. Statoacoustic ganglion size was significantly reduced, which suggested that neuron differentiation or maturation was affected. Furthermore, cdh2 loss-of-function did not cause a general developmental delay, since differentiation of other tissues, including eye, proceeded normally. These findings demonstrate that Cdh2 selectively affects epithelial morphogenetic cell movements, particularly semicircular canal formation, during normal ear mophogenesis.
Ex vivo treatment with nitric oxide increases mesoangioblast therapeutic efficacy in muscular dystrophy
Authors: Sciorati Clara , Galvez Beatriz G. , Brunelli Silvia , Tagliafico Enrico , Ferrari Stefano , Cossu Giulio , Clementi Emilio
Published: December 2006

Muscular dystrophies are characterized by primary wasting of skeletal muscle for which no satisfactory therapy is available. Studies in animal models have shown that stem cell-based therapies may improve the outcome of the disease, and that mesoangioblasts are promising stem cells in this respect. The efficacy of mesoangioblasts in yielding extensive muscle repair is, however, still limited. We found that mesoangioblasts treated with nitric oxide (NO) donors and injected intra-arterially in α-sarcoglycan-null dystrophic mice have a significantly enhanced ability to migrate to dystrophic muscles, to resist their apoptogenic environment and engraft into them, yielding a significant recovery of α-sarcolgycan expression. In vitro NO-treated mesoangioblasts displayed an enhanced chemotactic response to myotubes, cytokines and growth factors generated by the dystrophic muscle. In addition, they displayed an increased ability to fuse with myotubes and differentiating myoblasts and to survive when exposed to cytotoxic stimuli similar to those present in the dystrophic muscle. All the effects of NO were cyclic GMP-dependent since they were mimicked by treatment with the membrane permeant cyclic-GMP analogue 8-bromo-cGMP and prevented by inhibiting guanylate cyclase. We conclude that NO donors exert multiple beneficial effects on mesoangioblasts that may be used to increase their efficacy in cell therapy of muscular dystrophies.
When intracellular logistics fails - genetic defects in membrane trafficking
Authors: Olkkonen Vesa M. , Ikonen Elina
Published: December 2006

The number of human genetic disorders shown to be due to defects in membrane trafficking has greatly increased during the past five years. Defects have been identified in components involved in sorting of cargo into transport carriers, vesicle budding and scission, movement of vesicles along cytoskeletal tracks, as well as in vesicle tethering, docking and fusion at the target membrane. The nervous system is extremely sensitive to such disturbances of the membrane trafficking machinery, and the majority of these disorders display neurological defects - particularly diseases affecting the motility of transport carriers along cytoskeletal tracks. In several disorders, defects in a component that represents a fundamental part of the trafficking machinery fail to cause global transport defects but result in symptoms limited to specific cell types and transport events; this apparently reflects the redundancy of the transport apparatus. In groups of closely related diseases such as Hermansky-Pudlak and Griscelli syndromes, identification of the underlying gene defects has revealed groups of genes in which mutations lead to similar phenotypic consequences. New functionally linked trafficking components and regulatory mechanisms have thus been discovered. Studies of the gene defects in trafficking disorders therefore not only open avenues for new therapeutic approaches but also significantly contribute to our knowledge of the fundamental mechanisms of intracellular membrane transport.
Periplakin-dependent re-organisation of keratin cytoskeleton and loss of collective migration in keratin-8-downregulated epithelial sheets
Authors: Long Heather A. , Boczonadi Veronika , McInroy Lorna , Goldberg Martin , Määttä Arto
Published: December 2006

Collective migration of epithelial sheets requires maintenance of cell-cell junctions and co-ordination of the movement of the migrating front. We have investigated the role of keratin intermediate filaments and periplakin, a cytoskeletal linker protein, in the migration of simple epithelial cells. Scratch wounding induces bundling of keratins into a cable of tightly packed filaments adjacent to the free wound edge. Keratin re-organisation is preceded by a re-distribution of periplakin away from the free wound edge. Periplakin participates with dynamic changes in the keratin cytoskeleton via its C-terminal linker domain that co-localises with okadaic-acid-treated keratin granules. Stable expression of the periplakin C-terminal domain increases keratin bundling and Ser431 keratin phosphorylation at wound edge resulting in a delay in wound closure. Ablation of periplakin by siRNA inhibits keratin cable formation and impairs wound closure. Knockdown of keratin 8 with siRNA results in (1) a loss of desmoplakin localisation at cell borders, (2) a failure of MCF-7 epithelial sheets to migrate as a collective unit and (3) accelerated wound closure in vimentin-positive HeLa and Panc-1 cell lines. Thus, keratin 8 is required for the maintenance of epithelial integrity during migration and periplakin participates in the re-organisation of keratins in migrating cells.
Acute downregulation of connexin43 at wound sites leads to a reduced inflammatory response, enhanced keratinocyte proliferation and wound fibroblast migration
Authors: Mori Ryoichi , Power Kieran T. , Wang Chiuhui Mary , Martin Paul , Becker David L.
Published: December 2006

Experimental downregulation of connexin43 (Cx43) expression at skin wound sites appears to markedly improve the rate and quality of healing, but the underlying mechanisms are currently unknown. Here, we have compared physiological and cell biological aspects of the repair process with and without Cx43 antisense oligodeoxynucleotide treatment. Treated wounds exhibited accelerated skin healing with significantly increased keratinocyte and fibroblast proliferation and migration. In vitro knockdown of Cx43 in a fibroblast wound-healing model also resulted in significantly faster healing, associated with increased mRNA for TGF-β1, and collagen α1 and general collagen content at the wound site. Treated wounds showed enhanced formation of granulation tissue and maturation with more rapid angiogenesis, myofibroblast differentiation and wound contraction appeared to be advanced by 2-3 days. Recruitment of both neutrophils and macrophages was markedly reduced within treated wounds, concomitant with reduced leukocyte infiltration. In turn, mRNA levels of CC chemokine ligand 2 and TNF-α were reduced in the treated wound. These data suggest that, by reducing Cx43 protein with Cx43-specific antisense oligodeoxynucleotides at wound sites early in the skin healing process repair is enhanced, at least in part, by accelerating cell migration and proliferation, and by attenuating inflammation and the additional damage it can cause.
Probing the integrin-actin linkage using high-resolution protein velocity mapping
Authors: Brown Claire M. , Hebert Benedict , Kolin David L. , Zareno Jessica , Whitmore Leanna , Horwitz Alan Rick , Wiseman Paul W.
Published: December 2006

Cell migration is regulated in part by the connection between the substratum and the actin cytoskeleton. However, the very large number of proteins involved in this linkage and their complex network of interactions make it difficult to assess their role in cell migration. We apply a novel image analysis tool, spatio-temporal image correlation spectroscopy (STICS), to quantify the directed movements of adhesion-related proteins and actin in protrusions of migrating cells. The STICS technique reveals protein dynamics even when protein densities are very low or very high, and works in the presence of large, static molecular complexes. Detailed protein velocity maps for actin and the adhesion-related proteins α-actinin, α5-integrin, talin, paxillin, vinculin and focal adhesion kinase are presented. The data show that there are differences in the efficiency of the linkage between integrin and actin among different cell types and on the same cell type grown on different substrate densities. We identify potential mechanisms that regulate efficiency of the linkage, or clutch, and identify two likely points of disconnect, one at the integrin and the other at α-actinin or actin. The data suggests that the efficiency of the linkage increases as actin and adhesions become more organized showing the importance of factors that regulate the efficiency in adhesion signaling and dynamics.
BSSE-corrected Three-body Interaction Energy in the Recognition of GC Base Pair by Asparagine
Authors: Yoshida Tomoki , Aida Misako
Published: December 2006

We investigate the total binding energy and many-body components in the recognition of guanine (G)–cytosine (C) base pair by asparagine residue (N). There are two possible bridged recognition structures for GCN trimers; one is in the major groove and the other is in the minor groove. The hydrogen-bonding pattern is the same for both trimers, while the binding energies and the components are significantly different. Three-body interaction energy depends on the binding site of N on GC pair. The difference in the relative direction between the dipole moments of GC base pair and N may partly account for the difference in the two-body interaction energies of the trimers.
Ellipsoidal Carbon Capsules Encapsulated Magnetite Nanorods
Authors: Hao Ling-Yun , Xuan Shou-Hu , Gong Xing-Long , Gu Rui , Jiang Wan-Quan , Chen Zu-Yao
Published: December 2006

A novel ellipsoidal carbon capsules, with submicrometer sizeed Fe3O4 nanorods inside, were fabricated by in situ carbonization–reduction process from sandwich α-Fe2O3@Air@polypyrrole ellipsoidal spheres in vacuum at 823 K.
Enhanced Photocatalytic Activities of Core–Shell Au–Titanate Nanoparticles
Authors: Hayakawa Tomokatsu , Hori Mamiko , Pagnoux C , Baumard J F , Nogami Masayuki
Published: December 2006

Recently, a new method to produce Au nanoparticles (Au-NPs) by in situ reduction of a Au salt using 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt (Tiron) in water was reported. The Au-NPs of 8 nm in the typical average size were adsorbed by ionized Tiron and were dispersed in sol by electrical repulsive force. By addition of titanium butoxide, titanium hydroxide was coated onto Au-NPs via ionized Tiron and, the core–shell particles of Au@titanate were successfully created. Such nanocomposites had high photocatalytic effects for the decomposition of Methylene Blue.
Readily Regenerative and Air-stable Palladium(0) Catalyst with Tris[2-(diphenylphosphino)ethyl]phosphine Tetrasulfide for C–C Coupling Reactions
Authors: Aizawa Sen-ichi , Tamai Mitsuyoshi , Sakuma Mai , Kubo Asari
Published: December 2006

The novel air-stable Pd0 complex, [Pd(pp3S4)(dba)] (pp3S4 = tris[2-(diphenylphosphino)ethyl]phosphine tetrasulfide, dba = dibenzylideneacetone) was prepared as a C–C coupling catalyst. This is regenerative from the Pd0 complex with the partially oxidized pp3S4 ligand by the chalcogen-atom substitution reaction catalyzed by Pd0 and applicable to the recyclable Pd0 catalytic system.
Bioelectrocatalytic Reduction of O2 Catalyzed by CueO from Escherichia coli Adsorbed on a Highly Oriented Pyrolytic Graphite Electrode
Authors: Miura Yuko , Tsujimura Seiya , Kamitaka Yuji , Kurose Shinji , Kataoka Kunishige , Sakurai Takeshi , Kano Kenji
Published: December 2006

CueO from Escherichia coli, a member of the multi-copper oxidase (MCO) family, was examined as a direct electron transfer-type bioelectrocatalyst for the four-electron reduction of O2. Although CueO requires the fifth copper located near the type I Cu site to exhibit its oxidase activity (Roberts et al., 2003), it has been found that CueO receives electrons directly from electrodes even in the absence of the fifth copper. The fact indicates that electrons are transferred directly from electrodes to the type I Cu site. Furthermore, the catalytic current density of as large as about −4 mA cm−2 was successfully observed with a rotating pyrolytic graphite electrode at pH 5. CueO is found to be superior to other MCOs in view of the catalytic activity and is an important candidate as a catalyst of the cathode in biofuel cells.
Consequence of a Defect on the Terahertz Spectra of l-Asparagine Monohydrate
Authors: Nishizawa Jun-ichi , Tanno Takenori , Yoshida Takashi , Suto Ken
Published: December 2006

We measured the terahertz vibrational spectra of a solid solution of l-asparagine and l-aspartic acid monohydrate at 0.5 to 6.0 THz using a GaP Raman THz spectrometer. The absorption peaks at below 2.5 THz clearly showed intensity changes reflecting the change in hydrogen bonding between molecules. The peaks in the higher frequency region were indirectly affected by intermolecular bonding, which resulted in broadening.
Selective Visual Determination of Vanadium(V) Ion in Highly Acidic Solution Using Desferrioxamine B Immobilization Cellulose
Authors: Takagai Yoshitaka , Yamaguchi Hitoshi , Kubota Toshio , Igarashi Shukuro
Published: December 2006

The vanadium ion in a strong acidic aqueous solution was visually detected and determined without pretreatment. This is achieved by chemically immobilizing the desferrioxamine B (DFB) on cellulose paper. The color of the cellulose paper selectively changes to purple. Though DFB is known to form several colored complexes, the vanadium complex could be selectively detected using the overlap of the color tone between the complexes and background, and/or using EDTA.
Efficient Synthesis of Amylbenzenes over Zeolite Catalysts
Authors: Zhang Huanyan , Liu Yueming , Wu Haihong , Jiang Yongwen , He Mingyuan , Wu Peng
Published: December 2006

The liquid-phase heterogeneous alkylation of benzene with 2-methyl-2-butene takes place actively and selectively over large-pore zeolite catalysts, which implies an environmentally friendly route for the synthesis of tert-amylbenzene.
Effect of Arginine at Type 2 Cu Site on Spectroscopic Features and Enzymatic Activity of Copper-containing Nitrite Reductase
Authors: Yamaguchi Kazuya , Tsuda Aiko , Nojiri Masaki , Suzuki Shinnichiro
Published: December 2006

Spectroscopic features and enzymatic activity of H135R nitrite reductase mutant, in which a His ligand at the type 2 copper site is replaced with Arg, have been investigated to get information on unique nitrite reductases having one Arg at the type 2 copper site. Although the substitution of Arg for His slightly perturbed the structure of copper sites, the enzymatic activity was considerably lower than that of wild-type enzyme.
Self-assembled Gold Nanoparticle Chains in Presence of Silver Ions
Authors: Sun Lanlan , Song Yonghai , Wei Gang , Wang Li , Guo Cunlan , Sun Yujing , Li Zhuang
Published: December 2006

A simple method has been developed to assemble gold nanoparticles to generate 1D assemblies by the assistance of silver ions. The lengths of nanoparticle chains can be controlled by adjusting the content of silver ions in the system. The assembly procedure of gold nanoparticles chains requires no template. The gold nanoparticle chains were characterized using TEM and XPS techniques.
Exfoliation-free Nanosheet Synthesis of Transition-metal Hydroxynitrate and Its Transformation to Oxide Particulate Nanosheet
Authors: Cui Hongtao , Zayat Marcos , Levy David
Published: December 2006

A new strategy, epoxide-assisted precipitation route presented in this work, allows the exfoliation-free nanosheet synthesis of Ni3(NO3)2(OH)4 by the control of dynamics of the precipitation reaction. The mechanism of growth limitation in the third direction can be explained by the bonding of the molecule resulting from the ring-opening reaction of the epoxide to the surface of primary nanosheets, preventing the thickening of the layer.
Claisen Rearrangement Strategy in Alkenyl Dihydropyran Leading to Total Synthesis of (+)-α-Vetispirene and (−)-Agarospirol
Authors: Nakazaki Atsuo , Kobayashi Susumu
Published: December 2006

Total synthesis of (+)-α-vetispirene and (−)-agarospirol based on a Claisen rearrangement has been achieved. This is the first example of a Claisen rearrangement in an enantio-enriched alkenyl bicyclic dihydropyran system with perfect asymmetric transmission.
Catalytic Asymmetric Addition of Alkynylzinc Reagents to Nitrones
Authors: Konishi Atsuko , Wei Weilin , Kobayashi Masato , Fujinami Shuhei , Ukaji Yutaka , Inomata Katsuhiko
Published: December 2006

The catalytic asymmetric addition of alkynylzinc reagents, which were prepared in situ from dimethylzinc and 1-alkynes, to nitrones was achieved by utilizing di(t-butyl) (R,R)-tartrate as a chiral auxiliary to afford the corresponding optically active (R)-N-(α-substituted)propargylic hydroxylamines. By the addition of methylzinc salt of a product-like racemic hydroxylamine, enantioselectivity of the N-propargylic hydroxylamines was enhanced up to 96% ee.
Estimating Liquid Oxygen Requirements for Aeration of Fasted Channel Catfish
Authors: Pearson Philip R , Beecham Rachel V
Published: December 2006

A review of the scientific literature concerning the respiration of channel catfish Ictalurus punctatus resulted in development of a Microsoft Excel spreadsheet for estimating the volume of oxygen consumed by a given fasted channel catfish biomass. Channel catfish farmers and live haulers using diffused oxygen aeration systems can use computed estimates of oxygen consumption as a guide for setting flow rates for diffusers placed in grading nets and haul tanks. Entry of eight variables into the spreadsheet provides estimates of oxygen gas consumption with respect to time and biomass, the liquid oxygen equivalent of that volume, liquid oxygen expense, and the ratio of liquid oxygen expense to gross revenue.
Preparation of SAMS-CMC-CS bipolar membrane and its application in electro-generating FeO42−
Authors: Ren Yuxi , Chen Zhen , Chen Riyao , Zheng Xi , Geng Yamin
Published: December 2006

The preparation of SAMS-CMC-CS bipolar membrane grafted onto CMC by SAMS was reported. The cross-section view of SAMS-CMC-CS BM were studied by SEM. FT-IR spectrum indicated that SAMS-CMC-CS BM contained-SO 3−,-COO− and −N=CHR functional groups. Compared with CMC-CS BM, SAMS-CMC-CS BM appears to have better mechanical strength and chemical stability in alkali solution at [OH−]≥9.5 mol/L, with a swelling of 55 %. The electrochemical properties of SAMS-CMC-CS BM were also studied. SAMS-CS-CMC BM not only effectively prevented FeO 42− from diffusing into the cathode chamber, but also played an important role in the supply of OH− consumed during the electro-generated FeO 42− process.
Image-to-patient registration by natural anatomical surfaces of the head
Authors: Marmulla Rüdiger , Mühling Joachim , Eggers Georg
Published: December 2006

The use of registration markers in computer-assisted surgery is combined with high logistic costs and efforts.

During the preparation of image guided surgery, automated markerless patient-to-image registration based on anatomical surfaces allows a significant reduction of preoperative effort and of the radiation dose the patient is exposed to. Placement and measurement of radio-opaque fiducial markers becomes unnecessary. The usability of face, auricle, maxilla and mandible for surface-based registration to CT image data was investigated. The present study was performed to evaluate the clinical accuracy in finding defined target points within the surgical site after markerless patient registration in image-guided oral and maxillofacial surgery.

Preoperatively, the spatial position of 20 patients was registered to CT image data using a 3D laser surface scanner. Indications for surgery were tumours, foreign bodies and skeletal malformations. The accuracy of this surface-based registration was verified using additionally placed fiducial markers.

The study showed, that markerless surface-based registration was sufficiently accurate for clinical use when the surface used for matching was the upper jaw, the face, or — with reservations — the auricle. Surface-based registration using the mandible did not yield satisfying results. To conclude, image-to-patient registration based on laser surface scanning is a valuable method for surgery of the head. Multiple sites of the head were identified as appropriate for the method. Hence, dependent on the individual case and the intended surgery, the registration area can be selected with the necessary flexibility.
Estimation of the probability of fighting in fallow deer (Dama dama) during the rut
Authors: Bartoš Luděk , Fričová Barbora , Bartošová‐Víchová Jitka , Panamá José , Šustr Pavel , Šmídová Eva
Published: December 2006

Fighting between males is a frequent component of the rutting behavior of Cervidae. Frequent conflicts are exhausting; fighting may be risky and can lead to serious injuries or even death. We focused on the process of assessment of the opponent's fighting ability and escalation of the combat, estimating the probability of fighting based on the encounter components such as groaning and parallel walk. In this study, we observed the agonistic behavior of fallow deer bucks (Dama dama) during the rut over four seasons. During this time, we recorded 205 encounters between bucks. Non‐contact display, which allows contestants to assess their opponents fighting ability, occurred in 83% of the encounters. The highest predicted probability of a fight was found when both of the males vocalized and turned into the parallel walk. The chance of a clear outcome decreased when the males were fighting in comparison to when they did not fight. The initiator of the competitive encounter won 41% of the cases, while the attacked buck won 23% of the encounters. If the contestants avoided fighting, however, the initiator won 78% of encounters. Therefore, the initiator was more successful when no fight occurred compared to when the encounters escalated into fighting. In most cases where ritualized behavior occurred, one of the opponents left after vocalization or parallel walk occurred. Thus, vocalization and parallel walk increased the probability for a clear outcome. The probability of a fight was lowest in situations where the males displayed asymmetric behavior. Increased symmetry of the contestants' behavior was strongly correlated with a higher probability of a fight. Thus, these results indicate that fallow deer bucks use efficient tactic during the rut, which, in turn, minimizes the chance of injury while fighting during the breeding season. Aggr. Behav. 33:7–13, 2007. © 2006 Wiley‐Liss, Inc.
Age differences in the prevalence of physical aggression among 5–11‐year‐old Canadian boys and girls
Authors: Lee Kyung‐Hye , Baillargeon Raymond H. , Vermunt Jeroen K. , Wu Hong‐Xing , Tremblay Richard E.
Published: December 2006

It has been proven extremely difficult in the past to estimate the prevalence of physical aggression in children for two main reasons: (a) a heterogeneous sampling of behaviors (i.e., mix between physically aggressive and non‐physically aggressive antisocial behaviors), and (b) a lack of a “gold standard” to identify children who exhibit physically aggressive behaviors on a frequent basis. The goal of this study was to test for age differences in the prevalence of physical aggression in the Canadian population of school‐aged boys and girls, using cross‐sectional data from the National Longitudinal Survey of Children and Youth (NLSCY). The first wave of the NLSCY included a representative sample of 12,292 Canadian children aged 5–11 years. We used latent class analysis to identify children whose propensity to exhibit physically aggressive behaviors was much higher than that of other children of the same age and sex in the population. The prevalence of physical aggression was estimated at 3.7% in 5–11‐year‐old boys and ranged from .5% to 2.3% in 11 and 5‐year‐old girls, respectively. Hence, the results show a decreasing trend in the prevalence of physical aggression with age for girls, but not for boys. These findings suggest the importance of considering the developmental pathways of physical aggression for boys and girls separately. Aggr. Behav. 33:26–37, 2007. © 2006 Wiley‐Liss; Inc.
Ontogeny of sex differences in defensive burying behavior in rats: effect of social isolation
Authors: Arakawa Hiroyuki
Published: December 2006

The aim of the present experiments was to clarify sex differences in socio‐developmental factors that affected defense behavior in rats. Sex differences in the defensive burying behavior of rats, and related social factors, were explored in three developmental stages: juvenile, puberty, and adult; 30, 50, and 80 days of age, respectively. The duration of burying, digging into bedding material, stretch‐attend postures, and crouch/freezing were measured in a shock‐prod test. For males, the duration of burying was longer in the juvenile and pubertal stages than in adulthood. For females, no age differences in the duration of burying were found. Males showed longer burying durations than females in both the juvenile and pubertal stages. For both sexes, the highest duration of digging was found in the juvenile stage, and females showed longer durations of digging than males. Both male and female rats isolated during the juvenile stage, from 26 to 40 days of age, showed smaller durations of burying behavior compared to pair‐reared rats. This effect of juvenile isolation was maintained among both adult males and females even when they were returned to pair rearing after isolation. Isolation during adulthood, from 66 to 80 days of age, increased burying behavior in males, but decreased it in females. The durations of digging, stretch‐attend postures, and crouch/freezing were not affected by isolation. The decrease in defensive burying and its increase resulting from isolation in adult male rats, suggest that the emergence of adult‐like social relationships in males suppressed the duration of burying. Male and female rats isolated during the juvenile stage maintained lower levels of burying, suggesting that social experience as juveniles is important for the emergence of defensive burying behavior. Aggr. Behav. 33:38–47, 2007. © 2006 Wiley‐Liss; Inc.
Civic community and violent behavior in Italy
Authors: Gatti Uberto , Tremblay Richard E. , Schadee Hans
Published: December 2006

The aim of this study was to examine to what extent community characteristics counterbalance propensities towards homicide and robbery. Data were obtained for each of the 95 Italian provinces on homicide rate and robbery rate from 1992 to 1995. Multiple regressions were used to predict these homicide and robbery rates from a measure of civic engagement (Civicness) assessed during the same period, and from other socioeconomic variables: unemployment, family break up, and geographical characteristics. The predictors explained 77% of the variance among the Italian provinces for robbery, and 61% of the variance for homicide. The predictive patterns were somewhat different for homicide and robbery, but in each case civicness interacted with territorial variables. In the case of homicide, civicness had a preventive impact only in the southern provinces. For robbery, the protective impact was limited to provinces which were urbanized and had large metropolitan areas. Aggr. Behav. 33:56–62, 2007.© 2006 Wiley‐Liss, Inc.
Officer attitudes towards adult male prisoners who self‐harm: development of an attitudinal measure and investigation of sex differences
Authors: Ireland Jane L. , Quinn Karen
Published: December 2006

Purpose: The aim of the current study was to explore attitudes towards self‐harm in a sample of prison officers, with subsidiary aims of assessing if these attitudes alter as a function of the prisoner's behavior and the sex of the participant.

Method: One hundred and sixty‐two officers (100 men and 62 women) completed a general measure of their attitudes towards prisoners and one designed to assess Attitudes towards Prisoners who Self‐Harm (APSH). Participants rated their perceptions of two adult male prisoners depicted in vignettes. The vignettes depicted identical types of self‐harm but varied the behavioral characteristics of the prisoners involved, with one depicted as “well‐behaved” and the other as “disruptive”.

Results: Women were more likely than men to report positive attitudes towards self‐harm and in particular were less likely than men to endorse negative myths regarding self‐harm. The prisoner depicted as “disruptive” invoked increased negative attitudes than the “well‐behaved” prisoner. This finding was consistent across sex.

Conclusion: The current study indicates that APSH are comprised of a number of components that were influenced by the sex of the participant and the behavioral characteristics of the prisoners depicted. The implications of these findings to practice are discussed. Aggr. Behav. 33:63–72, 2007. © 2006 Wiley‐Liss, Inc.
Applying the concept of lifestyle in association with aggression and violence in Greek cohabitating couples
Authors: Tzamalouka Georgia S. , Parlalis Stavros K. , Soultatou Pelagia , Papadakaki Maria , Chliaoutakis Joannes El.
Published: December 2006

The current study investigated the role of lifestyle as a significant factor related to the aggression and violence between cohabitating partners. Based on previous research, lifestyle was defined as a special reflection of socialization into society and working life, where different lifestyles should also be able to produce different patterns of socialization into people's roles as partners. It was found that gender and years of cohabitating were significantly related to Emotional aggression and Sexual violence; lifestyle patterns were associated with specific forms of violence. More specifically, the lifestyles of Pleasure & Elegance and the one of Culture–Intellectualism were found to promote Emotional aggression. Also, the lifestyle of Yuppies/Workaholic and that of Physical activities stimulated the appearance of Sexual violence between partners. Moreover, individuals with Tradition–Religiousness lifestyle were more likely to show lower levels of Physical & Sexual violence while the adherents of the Substance abuse lifestyle pattern appeared to have an inclination towards Physical & Sexual Violence. Finally, the occurrence of one form of violent behaviour was likely to be related to the other forms of violent behaviour. Aggr. Behav. 33:73–85, 2007. © 2006 Wiley‐Liss, Inc.
Cationic Conjugated Polyelectrolytes with Molecular Spacers for Efficient Fluorescence Energy Transfer to Dye‐Labeled DNA
Authors: Woo H. Y. , Vak D. , Korystov D. , Mikhailovsky A. , Bazan G. C. , Kim D.‐Y.
Published: December 2006

Two water‐soluble conjugated polyelectrolytes, poly(9,9′‐bis(6‐N,N,N‐trimethylammoniumhexyl)fluorene‐alt‐1,4‐(2,5‐bis(6‐N,N,N‐trimethylammoniumhexyloxy))phenylene) tetrabromide (P1i) and poly((10,10′‐bis(6‐N,N,N‐trimethylammoniumhexyl)‐10H‐spiro(anthracene‐9,9′‐fluorene))‐alt‐1,4‐(2,5‐bis(6‐N,N,N‐trimethylammoniumhexyloxy))phenylene) tetrabromide (P2i) are synthesized, characterized, and used in fluorescence resonance energy transfer (FRET) experiments with fluorescein‐labeled single‐stranded DNA (ssDNA‐Fl). P1i and P2i have nearly identical π‐conjugated backbones, as determined by cyclic voltammetry and UV‐vis spectroscopy. The main structural difference is the presence of an anthracenyl substituent, orthogonal to the main chain in each of the P2i repeat units, which increases the average interchain separation in aggregated phases. It is possible to observe emission from ssDNA‐Fl via FRET upon excitation of P2i. Fluorescein is not emissive within the ssDNA‐Fl/P1i electrostatic complex, suggesting Fl emission quenching through photoinduced charge transfer (PCT). We propose that the presence of the anthracenyl “molecular bumper” in P2i increases the distance between optical partners, which decreases PCT more acutely relative to FRET.
Highly Organized Mesoporous TiO2 Films with Controlled Crystallinity: A Li‐Insertion Study
Authors: Fattakhova‐Rohlfing D. , Wark M. , Brezesinski T. , Smarsly B. M. , Rathouský J.
Published: December 2006

A study of electrochemical Li insertion combined with structural and textural analysis enabled the identification and quantification of individual crystalline and amorphous phases in mesoporous TiO2 films prepared by the evaporation‐induced self‐assembly procedure. It was found that the properties of the amphiphilic block copolymers used as templates, namely those of a novel poly(ethylene‐co‐butylene)‐b‐poly(ethylene oxide) polymer (KLE) and commercial Pluronic P123 (HO(CH2CH2O)20(CH2CH(CH3)O)70(CH2CH2O)20H), decisively influence the physicochemical properties of the resulting films. The KLE‐templated films possess a 3D cubic mesoporous structure and are practically amorphous when calcined at temperatures below 450 °C, but treatment at 550–700 °C provides a pure‐phase (anatase), fully crystalline material with intact mesoporous architecture. The electrochemically determined fraction of crystalline anatase increases from 85 to 100 % for films calcined at 550 and 700 °C, respectively. In contrast, the films prepared using Pluronic P123, which also show a 3D cubic pore arrangement, exhibit almost 50 % crystallinity even at a calcination temperature of 400 °C, and their transformation into a fully crystalline material is accompanied by collapse of the mesoporous texture. Therefore, our study revealed the significance of using suitable block‐copolymer templates for the generation of mesoporous metal oxide films. Coupling of both electrochemical and X‐ray diffraction methods has shown to be highly advisable for the correct interpretation of structure properties, in particular the crystallinity, of such sol–gel derived films.