bluuebunny/crossref_metadata_2025 huggingface dataset:
Larval electroreceptors in the epidermis of mormyrid fish: II. The promormyromast
Authors: Denizot Jean‐Pierre , Bensouilah Mourad , Roesler Ritva , Schugardt Christian , Kirschbaum Frank
Published: February 2007

Promormyromasts were found in the epidermis of the head of the larvae of five species of mormyrids bred in captivity. The promormyromast is a larval electroreceptor belonging to the specific lateral line system. In 12‐day‐old larvae this electroreceptor is characterized by a single sensory cell and two types of accessory cells. One type of accessory cell has dark cytoplasm, few microtubules, and contacts the sensory cell directly, whereas a second type has pale cytoplasm, many microtubules, and forms an outer layer not directly in contact with the sensory cell. This second type is referred to as a long pyriform accessory cell. This assembly of cells is situated below an intraepidermal cavity filled with acid polysaccharides. The bordering epidermal cells extend microvilli into the intraepidermal cavity. The apexes of the sensory cell, and of the two types of accessory cells, also open into the intraepidermal cavity but bear no microvilli. The promormyromast is innervated by an unmyelinated sensory nerve fiber passing through the basal membrane, which then splits into several branches between the accessory cells. These branches contact the periphery of the sensory cell with terminal boutons. At the site of each contact a ribbon‐like structure surrounded by vesicles is present in the cytoplasm of the sensory cell. In older larvae of Campylomormyrus cassaicus, membrane foldings develop at the periphery of the pyriform accessory cells and accessory cell staining properties change just before transformation to become a mormyromast. The functional role of the promormyromast of the larval mormyrids is discussed. J. Comp. Neurol. 501:810–823, 2007. © 2007 Wiley‐Liss, Inc.
Colocalization of metabotropic glutamate receptors in rat dorsal root ganglion cells
Authors: Carlton Susan M. , Hargett Gregory L.
Published: February 2007

Glutamate is the main excitatory transmitter in both central and peripheral nervous systems. Discovery of metabotropic glutamate receptors (mGluRs) made it clear that glutamate can have excitatory or inhibitory effects on neuronal function, with group I mGluRs enhancing cell excitability but group II and III mGluRs decreasing excitability. The present study investigated the colocalization of mGluR subtypes representing groups I, II, or III in rat L5 dorsal root ganglion (DRG) cells. The analyses show that group III has the highest expression, with 75.0% of DRG cells expressing mGluR8, followed by group II, with 51.6% expressing mGluR2/3, followed by group I, with only 6.8% expressing mGluR1α. mGluR8 is expressed by small, medium, and large diameter cells. In contrast, mGluR1α and mGluR2/3 are expressed by mainly small and medium cells. Approximately half of cells expressing group I mGluR1α also express either group II mGluR2/3 or group III mGluR8. These mGluR1α double‐labeled populations are not likely to overlap since >1.0% of mGluR1α are triple‐labeled. As expected from the high percentage of single‐labeled mGluR2/3 and mGluR8 cells, there is a considerable population of double‐labeled cells with ≈30% of each population expressing both receptors. Due to the fact that the number of mGluR1α‐expressing cells in the DRG is low, the percentage of triple‐labeled cells is also low (≈1–2%). The prevalence of groups II and III indicate that glutamate could have a substantial inhibitory effect of primary afferent function, reducing and/or fine‐tuning sensory input before transmission to the spinal cord. These anatomical data highlight the potential inhibitory role glutamate may play in peripheral sensory transmission. J. Comp. Neurol. 501:780–789, 2007. © 2007 Wiley‐Liss, Inc.
Morphology and electrophysiological properties of hamster spinal dorsal horn neurons that express VGLUT2 and enkephalin
Authors: Schneider Stephen P. , Walker Tracy M.
Published: February 2007

The excitatory amino acid glutamate mediates transmission at spinal synapses, including those formed by sensory afferent fibers and by intrinsic interneurons. The identity and physiological properties of glutamatergic dorsal horn neurons are poorly characterized despite their importance in spinal sensory circuits. Moreover, many intrinsic spinal glutamatergic synapses colocalize the opioid peptide enkephalin (ENK), but the neurons to which they belong are yet to be identified. Therefore, we used immunohistochemistry and confocal microscopy to investigate expression of the VGLUT2 vesicular glutamate transporter, an isoform reported in nonprimary afferent spinal synapses, and ENK in electrophysiologically identified neurons of hamster spinal dorsal horn. VGLUT2 immunoreactivity was localized in restricted fashion to axon varicosities of neurons recorded from laminae II–V, although the occurrence of immunolabeling in individual varicosities varied widely between cells (39 ± 36%, n = 31 neurons). ENK colocalized with VGLUT2 in up to 77% of varicosities (17 ± 21%, n = 21 neurons). The majority of neurons expressing VGLUT2 and/or ENK had axons with dense local terminations or projections consistent with propriospinal functions. VGLUT2 and ENK labeling were not correlated with cellular morphology, intrinsic membrane properties, firing patterns, or synaptic responses to sensory afferent stimulation. However, VGLUT2 expression was significantly higher in neurons with depolarized resting membrane potential. The results are new evidence for a population of dual‐function dorsal horn interneurons that might provide another mechanism for limiting excitation within dorsal horn circuits during periods of strong sensory activation. J. Comp. Neurol. 501:790–809, 2007. © 2007 Wiley‐Liss, Inc.
A stabilized finite element model for the hydrothermodynamical simulation of the Rio de Janeiro coastal ocean
Authors: Carbonel Carlos A. A. H. , Galeão Augusto C. N.
Published: February 2007

In this paper, a stabilized space–time Petrov–Galerkin finite element model of coastal ocean circulation is derived. Continuous linear interpolation in space and time is employed and a spatial unstructured mesh of triangular elements is used. To simulate the hydro‐thermodynamical ocean behaviour a gravity reduced model is proposed. This model solves the motion and continuity hydrodynamic equations coupled with the advection–diffusion transport equation for temperature which governs the heat exchanges in the upper layer. The model is used to evaluate the main dynamical features of the coastal waters of the Rio de Janeiro State, namely: cold plumes, coastal jets and the influence of the warmer water bays. Numerical experiments are performed to highlight the typical observed events of coastal upwelling phenomena and their interaction with the existing coastal bays and the offshore conditions. Such experiments deal with a series of idealized northeast wind field forcing patterns, showing the solutions dependence on the horizontal structure of the wind fields in relation to the coastline configuration. Copyright © 2007 John Wiley & Sons, Ltd.
Corporate governance and corporate social responsibility: issues for Asia
Authors: Welford Richard
Published: February 2007

An increasingly important aspect of CSR is the recognition that sound practices are often based on good standards of corporate governance. Good corporate governance provides the foundations of good CSR by creating value‐creating relationships with all stakeholders. This article seeks to review corporate governance issues from an Asian perspective. Ownership and control of many companies in the region differ from those commonly seen in the West and there are therefore specific issues that need to be addressed in this context. It is argued that the fact that so many Asian companies are dominated by controlling shareholders (often families) means that corporate governance may have to be even stronger in the Asian region than elsewhere. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Inducible expression of retrograde transynaptic genetic tracer in mice
Authors: Sano Hiromi , Nagai Yumiko , Yokoi Mineto
Published: February 2007

A key step towards understanding the development and function of the central nervous system is by characterizing the connections between neurons. Tetanus toxin C fragment (TTC) is transynaptically and retrogradely transported without the toxin's pathogenic effect, and therefore, recently it has been used as a genetic tracer combined with β‐galactosidase or green fluorescent protein. Here, we introduce a new fusion construct, APTTC, consisting of the truncated human placental alkaline phosphatase with TTC, and generating the transgenic mouse line, (tetracycline operator) tetO‐APTTC, for inducible expression of APTTC regulated by tetO. We demonstrate that APTTC is transported retrogradely and transynaptically, and allows us to robustly visualize the inputs of the expressing neurons when transgenetically expressed in mice, exemplified in the striatal neuronal circuit. Therefore, tetO‐APTTC transgenic mouse line can be widely used for visualization of neuronal connectivity when combined with mice carrying tetracycline‐controlled transactivator (tTA) in any specific neurons. genesis 45:123–128, 2007. © 2007 Wiley‐Liss, Inc.
Amphioxus AmphiDelta: evolution of delta protein structure, segmentation, and neurogenesis
Authors: Rasmussen Stacy L. K. , Holland Linda Z. , Schubert Michael , Beaster‐Jones Laura , Holland Nicholas D.
Published: February 2007

The amphioxus genome has a single Delta gene (AmphiDelta) encoding a protein 766 amino acids long. Comparison of Delta proteins of amphioxus and other animals indicates that AmphiDelta retains features of a basal bilaterian Delta protein—in having nine epidermal growth factor (EGF) repeats and also in having characteristic numbers of amino acids separating successive cysteines between and within EGF repeats. During development, AmphiDelta is expressed in the forming somites, in some regions of pharyngeal endoderm, and in cells (presumably differentiating neurons) scattered in both the neural plate and ectoderm. Expression is strongly associated with cells initiating movements to separate themselves from parent epithelia, either en masse by evagination (endoderm and mesoderm) or by delamination as isolated cells (ectoderm). The AmphiDelta‐expressing cells delaminating from the ectoderm apparently migrate beneath it as they begin differentiating into probable sensory neurons, suggesting a scenario for the evolutionary origin of the placode‐derived neurons of vertebrate cranial ganglia. genesis 45:113–122, 2007. Published 2007 Wiley‐Liss, Inc.
Caspase inhibition reduces lymphocyte apoptosis and improves host immune responses to Trypanosoma cruzi infection
Authors: Silva Elisabeth M. , Guillermo Landi V. C. , Ribeiro‐Gomes Flávia L. , De Meis Juliana , Nunes Marise P. , Senra Juliana F. V. , Soares Milena B. P. , DosReis George A. , Lopes Marcela F.
Published: February 2007

In experimental Chagas’ disease, lymphocytes from mice infected with Trypanosoma cruzi show increased apoptosis in vivo and in vitro. Treatment with a pan‐caspase blocker peptide inhibited expression of the active form of effector caspase‐3 in vitro and rescued both B and T cells from cell death. Injection of the caspase inhibitor benzyloxycarbonyl‐Val‐Ala‐Asp(OMe)‐fluoromethyl ketone, but not a control peptide, reduced parasitemia and lymphocyte apoptosis in T. cruzi‐infected mice. Moreover, treatment with caspase inhibitor throughout acute infection increased the absolute numbers of B and T cells in the spleen and lymph nodes, without affecting cell infiltrates in the heart. Following treatment, we found increased accumulation of memory/activated CD4 and CD8 T cells, and secretion of IFN‐γ by splenocytes stimulated with T. cruzi antigens. Caspase inhibition in the course of infection reduced the intracellular load of parasites in peritoneal macrophages, and increased the production of TNF‐α and nitric oxide upon activation in vitro. Our results indicate that inhibition of caspases with a pan‐caspase blocker peptide improves protective type‐1 immune responses to T. cruzi infection. We suggest that mechanisms of apoptosis are potential therapeutic targets in Chagas’ disease.
Priming of CD8+ T cell responses by pathogens typically depends on CD70‐mediated interactions with dendritic cells
Authors: Schildknecht Anita , Miescher Iris , Yagita Hideo , van den Broek Maries
Published: February 2007

The CD27/CD70‐interaction has been shown to provide a costimulatory and survival signal for T cells in vitro and in vivo. Recently, CD70 expression by DC was found to be important for the priming of CD8+ T cells. We show here that blocking CD70 interactions has a significant impact on priming of CD8+ T cell responses by vaccinia virus (VV), Listeria monocytogenes and vesicular stomatitis virus (VSV) in mice. However, the priming of specific CD8+ T cells upon infection with lymphocytic choriomeningitis virus (LCMV) was only marginally reduced by CD70‐blockade. Blocking of CD70 prevented CD8+ T cell priming in DIETER mice, a model in which presentation of LCMV‐derived epitopes can be induced selectively in dendritic cells (DC). In contrast, CD70‐CD27 interactions were not important for the priming of VSV‐specific CD4+ T cells or class switch of neutralizing antibodies. As we show that priming of CD8+ T cells by the pathogens used here is dependent on antigen presentation by DC and that infection results in up‐regulation of CD70 on DC, we conclude that CD70 expression on DC plays an important role in the priming of CD8+ T cells by pathogens. Moreover, the lack of CD70 cannot be completely compensated for by other costimulatory molecules.
New Dinuclear MnIII Compounds with 2‐MeC6H4COO and 2‐FC6H4COO Bridges – Effect of Terminal Monodentate Ligands (H2O, ClO4– and NO3–) on the Magnetic Properties
Authors: Fernández Gema , Corbella Montserrat , Aullón Gabriel , Maestro Miguel A. , Mahía José
Published: February 2007

Four new dinuclear MnIII complexes with the general formula [{Mn(bpy)L}(μ‐RCOO)2(μ‐O){Mn(bpy)L′}]n+ (bpy =2,2′‐bipyridine) have been synthesized with RCOO = 2‐MeC6H4COO (1, 2) and 2‐FC6H4COO (3, 4); the counteranion could be NO3– (1, 3) or ClO4– (2, 4), and a monodentate ligand (L, L′) completes the octahedral environment of the manganese ions. For compound 1 L = H2O and L′ = H2O or NO3–; compound 2 shows two different dinuclear complexes, one of them with L = L′ = H2O and the other one with L = L′ = ClO4–; for compound 3, L and L′ = H2O or NO3– and for compound 4, L = H2O and L′ = ClO4–. The characterization by X‐ray diffraction shows an important disorder in the crystal for the nitrate compounds, principally for compound 3, where each monodentate ligand could be a water molecule or a nitrate anion. The antiferromagnetic contribution to the magnetic coupling constant J is weaker for the nitrate compounds (1 and 3) than for the perchlorate compounds (2 and 4), and a ferromagnetic behaviour is found for compound 3, with J = +1.4 cm–1. The magnetic coupling constant found for compound 1 is J = –0.5 cm–1 and for compounds 2 and 4 it is –5.6 cm–1 and –3.5 cm–1, respectively. Extended Hückel calculations were carried out and there is evidence that the nitrate anions coordinated to the manganese atoms act as π‐acid ligands providing a means to diminish the antiferromagnetic contribution.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Helical Transition‐Metal Complexes of Constrained 2,2′‐Bidipyrrins
Authors: Bröring Martin , Link Stephan , Brandt Carsten D. , Tejero Esther Cónsul
Published: February 2007

Nickel(II), palladium(II), zinc(II) and copper(II) complexes of new constrained 2,2′‐bidipyrrin ligands (H2BDP) with a peripheral eight‐membered ring were prepared and examined with respect to coordination modes and conformation. NiII and PdII ions form mononuclear complexes with a distorted square‐planar N4 coordination, which was determined for the palladium derivative by single‐crystal X‐ray diffraction. ZnII ions lead to the formation of dinuclear M2L2 helicates, and for CuII ions both coordination modes are realized. X‐ray crystallographic analyses reveal short M···M distances for the dinuclear helicates of CuII and ZnII bidipyrrins and individually distinct packing patterns for both in the solid state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
First Structural Characterization of Silanedithiol and Its Application toward the Synthesis of Silanedithiolato Complexes
Authors: Tanabe Taro , Takeda Nobuhiro , Tokitoh Norihiro
Published: February 2007

In this paper, we report the synthesis and the structural characterization of stable examples of silanedithiol [Tbt(Mes)Si(SH)2 (1)], hydroxysilanethiol [Tbt(Mes)Si(OH)(SH) (3)], and hydroxysilaneselenol [Tbt(Mes)Si(OH)(SeH) (7)], which are kinetically stabilized by an effective combination of steric protection groups, Tbt (2,4,6‐tris[bis(trimethylsilyl)methyl]phenyl) and Mes (2,4,6‐trimethylphenyl). Silanedichalcogenols 1, 3, and 7 are suggested to exist as a monomer without any intermolecular contact such as hydrogen bonds both in the solid state and in solution as judged by X‐ray structural analysis and IR spectroscopy. Treatment of 1 with 2 equiv. of butyllithium resulted in the quantitative formation of the corresponding dilithium silanedithiolate, Tbt(Mes)Si(SLi)2 (8), the generation of which was confirmed by a trapping experiment using MeI. Furthermore, the addition of cis‐[MCl2(PPh3)2] (M = Pd, Pt) to a THF solution of 8 afforded the corresponding silanedithiolato complexes, [Tbt(Mes)Si(μ‐S)2M(PPh3)2] (9a: M = Pd; 9b: M = Pt), respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Mechanistic Studies on the Activation of NO by Iron and Cobalt Complexes (Eur. J. Inorg. Chem. 6/2007)
Authors: Franke Alicia , Roncaroli Federico , van Eldik Rudi
Published: February 2007

The cover picture shows how mechanistic insight into the activation of NO by biological and model metal complexes can be gained through volume profile analysis. The presented volume profile describes the binding of NO to the high‐spin, five‐coordinate FeIII centre in cytochrome P450 in the presence of camphor to form a low‐spin (diamagnetic), six‐coordinate FeII–NO+ product. Details are presented in the Microreview by R. van Eldik et al. on p. 773 ff.
Physical properties of lipase‐catalyzed interesterification of palm stearin with canola oil blends
Authors: Siew Wai Lin , Cheah Kien Yoo , Tang Wai Ling
Published: February 2007

Interesterified blends of hard palm stearin (IV of 11) and canola oil (hPS/CO) in ratios of 20 : 80, 30 : 70, 40 : 60, 50 : 50, 60 : 40 and 70 : 30 were prepared using immobilized Thermomyces lanuginosus lipase (Lipozyme TL IM). Comparison of physical properties was carried out between non‐interesterified and enzymatically interesterified products by monitoring their slip melting point (SMP), solid fat content (SFC), melting thermogram and polymorphism behavior. The Lipozyme TL IM‐catalyzed interesterification significantly modified the physical properties of the hPS:CO blends. The results showed that all the interesterified blends had lower SMP and SFC than their unreacted blends. The SMP result showed that the interesterified blends of hPS/CO 40 : 60, 50 : 50 and 60 : 40 could be useful for stick margarine and shortening applications, respectively. From the SFC analysis, the interesterified blends of hPS/CO 40 : 60 have SFC curves similar to vanaspati. The interesterified blends of hPS/CO 50 : 50 and 60 : 40 have SFC curves similar to margarines, puff pastry margarine and shortening. Interesterification had replaced the higher‐ and lower‐melting triacylglycerols by the middle‐melting triacylglycerols, yielding mixtures of lower SMP and SFC, compared to the original palm stearin. X‐ray diffraction analysis indicated the appearance of β' crystals in all the interesterified hPS/CO blends from predominantly β‐type oils.
Lipase‐catalyzed production of medium‐chain triacylglycerols from palm kernel oil distillate: Optimization using response surface methodology
Authors: Low Chee Tein , Mohamad Rosfarizan , Tan Chin Ping , Long Kamariah , Ismail Rosnah , Lo Seong Koon , Lai Oi Ming
Published: February 2007

Optimization of lipase‐catalyzed esterification for the production of medium‐chain triacylglycerols (MCT) from palm kernel oil distillate and glycerol was carried out in order to determine the factors that have significant effects on the reaction system and MCT yield. Novozyme 435 from Candida antarctica lipase was found to have the highest activity at 52.87 ± 0.03 U/g. This lipase also produced the highest MCT yield, which is 56.67%. The effect of different variables on MCT synthesis was studied with a two‐level five‐factor fractional factorial design. The various variables include (1) reaction temperature, (2) enzyme load, (3) molecular sieves concentration, (4) reaction time and (5) molar substrate ratio. Reaction temperature, reaction time and molar substrate ratio strongly affect MCT synthesis (p <0.05). However, enzyme load and molecular sieve concentration did not have a significant (p >0.05) influence on MCT yield. Therefore, the significant variables such as reaction temperature, reaction time and molar substrate ratio were further optimized through central composite rotatable design (CCRD). Comparisons between predicted and experimental values from the CCRD optimization procedures revealed good correlation, implying that the quadric response model satisfactorily expressed the percentage yield of MCT in the lipase‐catalyzed esterification. The optimum MCT yield is 73.3% by using 2 wt‐% enzyme dosage, a molecular sieves concentration of 1 wt‐%, a reaction temperature of 90 °C, a reaction time of 10 h and a molar substrate ratio of 4 : 1 (medium‐chain fatty acid/glycerol). Experiments to confirm the predicted results using the optimal parameters were conducted and an MCT yield of 70.21 ± 0.18% (n = 3) was obtained.
A novel method for color determination of edible oils in L*a*b* format
Authors: Kılıç Kıvanç , Onal‐Ulusoy Baran , Boyacı İsmail Hakkı
Published: February 2007

A simple method that uses visible spectrophotometer data and an artificial neural network (ANN) was developed to determine edible oil color based on the L*a*b* format. The 100 oil samples consisted of nine pure oils, a sesame oil blend and three heated oils. Binary, ternary and quaternary mixtures of these 13 oils in different ratios were prepared, and absorbance values of the samples were measured in the visible region (380–700 nm). The absorbance values at wavelengths of 416, 456, 483, 537, 611 and 672 nm were used to train, validate and test the network. Strong correlations between the instrumental L*a*b*ΔE and the estimated L*a*b*ΔE were found for the test samples, with correlation coefficients (R2) of 0.989, 0.984, 0.996 and 0.992 for L*, a*, b*, and ΔE, respectively. The effects of number and combination of the wavelengths used for training of the ANN on the estimation capability of the network for the test samples were also investigated. Although a good agreement, average R2 of 0.991– 0 993 for L*a*b*, was obtained for combinations composed of three to six wavelengths with 483 and 537 nm in common, the best R2 value was obtained when all six wavelengths were used to train the ANN. The developed method is objective, cost effective and simple, and allows the color measurement with a basic visible spectrophotometer and disposable cuvettes.
Epoxidation, hydroxylation, acrylation and urethanation of Linum usitatissimum seed oil and its derivatives
Authors: Sharmin Eram , Ashraf Syed Marghoob , Ahmad Sharif
Published: February 2007

Some preliminary studies on epoxidation, hydroxylation, acrylation and urethanation of Linum usitatissimum seed oil (LO) and its derivatives have been carried out. Epoxidation and hydroxylation were performed in situ using H2O2 and acetic acid to develop epoxidized oil (LOE) and epoxy polyol (EP). EP was modified with synthetic monomers, viz. acrylonitrile (AN) and methylmethacrylate (MMA), in the presence of benzoyl peroxide in an inert environment to develop acrylic grafted epoxy polyols (AEPs). EP and AEPs were further treated with an isocyanate, resulting in the formation of plain and acrylic grafted epoxy polyurethanes (EPU and AEPUs). The mechanism of the reaction as well as the structural aspects of LO, LOE, EP, AEPs, EPU and AEPUs were investigated by 1H‐NMR and 13C‐NMR spectroscopic techniques, which also confirmed the incorporation of the acrylic monomers – AN and MMA – on the EP backbone Spectral analyses further demonstrated that, depending on its structure (substituent), each acrylic monomer follows a different grafting mechanism. Physico‐chemical characterization of AEPs and AEPUs was carried out by standard laboratory methods, and thermal analyses were accomplished by TGA and DSC. Physico‐mechanical characterization of AEPUs coatings further showed considerable improvement compared to the pristine (EPU) resin, due to the introduction of stiff acrylic moieties. The aforementioned studies as well as the coating characteristics of AEPU confirmed that AN and MMA have been incorporated in the EP backbone. These systems can be safely employed at up to 210–220 °C.
Solid Phase and Solution Phase Structural Characterization of Pyrene‐Based, T‐Shaped Molecular Dyads
Authors: Lydon Donocadh P. , Li Peiyi , Benniston Andrew C. , McFarlane William , Harrington Ross W. , Clegg William
Published: February 2007

Structural solid‐phase and solution‐phase properties of two pyrene‐spiropyran molecular dyads are described. Each dyad comprises a 1,1′‐[indole‐4,6‐diylbis(ethyne‐2,1‐diyl)]bis(pyrene) backbone, with the bis(pyrene) and spiropyran units adopting a T‐shaped arrangement. The strength of the Cspiro–O bond is altered by replacement of H by NO2 in the terminal aryl group of the spiropyran unit. X‐ray crystal structure determinations carried out for two of the dyads (H and NO2) reveal the pyrene groups to be aligned anti to each other. The crystal packing diagrams are different; both contain pyrene π‐stacked centro‐symmetric dimers, but in one structure this is the total extent of the π stacking whereas the other structure has pyrene dimers interleaved to generate infinite parallel stacks. Detailed 1H NOE experiments are consistent with a solution‐phase structure that differs markedly from the solid‐state structure, and in which the pyrene groups are syn to one another but orientated away from the spiropyran group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Cover Picture: Novel Synthetic Cycloketo‐Tetraphenylporphyrins (Eur. J. Org. Chem. 7/2007)
Authors: Jasinski Stefan , Ermilov Eugeny A. , Jux Norbert , Röder Beate
Published: February 2007

The cover picture shows three tetraphenylporphyrins that possess an exocyclic keto‐group‐bearing ring connecting the central chromophore with one of the phenyl rings. Depending on the size of the exocyclic ring and on the additional steric strain induced by a methyl group on the substituted phenyl ring, the dihedral angle between the central chromophore and the phenyl ring varies between 15 and 55 °. These topological changes have a dramatic influence on, for example, the singlet‐oxygen quantum yield. As the generation of 1O2 is induced by red light, the setting sun (taken at San Diego beach in 2003 by Michael Köhl) seemed to be an appropriate background for the porphyrins. Details of the syntheses and characterization are reported in the article by N. Jux, B. Röder et al. on p. 1075 ff.
Quantitative analysis of cation binding to the adenosine nucleotides using the Variable Ionic Strength method: Validation of the Debye–Hückel–Onsager theory of electrophoresis in the absence of counterion binding
Authors: Stellwagen Earle , Stellwagen Nancy C.
Published: February 2007

The free solution mobilities of the adenosine nucleotides 5′‐adenosine triphosphate (ATP), 5′‐adenosine diphosphate (ADP), 5′‐adenosine monophosphate (AMP), and 3′‐5′‐cyclic AMP (cAMP) have been measured in diethylmalonate buffers containing a wide variety of monovalent cations. The mobilities of all nucleotides increase gradually with the increase in intrinsic conductivity of the cation in the BGE. However, at a given conductivity, the mobilities observed for ATP, ADP, and AMP in BGEs containing alkali metal ions and other cations are lower than these observed in BGEs containing tetraalkylammonium ions. Since the mobility of cAMP is independent of the cation in the BGE, the results suggest that the relatively low mobilities observed for ATP, ADP, and AMP in BGEs containing cations other than a tetraalkylammonium ion are due to cation binding, reducing the effective net charge of the nucleotide and thereby reducing the observed mobility. To measure the binding quantitatively, the mobilities of the nucleotides were measured as a function of ionic strength. The mobilities of ATP, ADP, and AMP decrease nonlinearly with the square root of ionic strength (I1/2) in BGEs containing an alkali metal ion or Tris+. By contrast, the mobilities decrease linearly with I1/2 in BGEs containing a nonbinding quaternary ammonium ion, as expected from Debye–Hückel–Onsager (DHO) theory. The mobility of cAMP, a nonbinding analyte, decreases linearly with I1/2, regardless of the cation in the BGE. Hence, a nonlinear decrease of the mobility of an analyte with I1/2 appears to be a hallmark of counterion binding. The curved mobility profiles observed for ATP, ADP, and AMP in BGEs containing an alkali metal ion or Tris+ were analyzed by nonlinear curve fitting, using difference mobility profiles to correct for the effect of the physical properties of BGE on the observed mobilities. The calculated apparent dissociation constants range from 22 to 344 mM, depending on the particular cation–nucleotide pair. Similar values have been obtained by other investigators, using different methods. Interestingly, Tris+ and Li+ bind to the adenosine nucleotides with approximately equal affinities, suggesting that positively charged Tris+ buffer ions can compete with alkali metal ions in Tris‐buffered solutions.
Volumetric methods for evaluating energy loss and heat transfer in cavity flows
Authors: Norris Stuart , Mallinson Gordon
Published: February 2007

Methods have been developed for calculating irreversible energy losses and rates of heat transfer from computational fluid dynamics solutions using volume integrations of energy dissipation or entropy production functions. These methods contrast with the more usual approach of performing first law energy balances over the boundaries of a flow domain. Advantages of the volumetric approach are that the estimates involve the whole flow domain and are hence based on more information than would otherwise be used, and that the energy dissipation or entropy production functions allow for detailed assessment of the mechanisms and regions of energy loss or entropy production.

Volume integrations are applied to the calculation of viscous losses in a lid‐driven cavity flow, and to the viscous losses and heat transfer due to natural convection in a side‐heated cavity. In the convection problem comparison with the entropy increase across a stationary heat conducting layer leads to a novel volume integral expression for the Nusselt number. The predictions using this method compare well with traditional surface integrals and benchmark results. Copyright © 2007 John Wiley & Sons, Ltd.
On level set modelling of bi‐fluid capillary flow
Authors: Lesage Anne‐Cécile , Allain Olivier , Dervieux Alain
Published: February 2007

We consider the adaptation of a level set (LS) method for the simulation of capillary flows on unstructured meshes. The advection step is first analysed. In order not to lose accuracy, this step should be one order more accurate than the discretization of the velocity. We then compare different ways in choosing the LS velocity and in re‐initializing the LS function between advection phases without losing too much accuracy. Applications to Rayleigh flows and to reorientation with contact angle are presented. Copyright © 2007 John Wiley & Sons, Ltd.
Numbering techniques for preconditioners in iterative solvers for compressible flows
Authors: Pollul B. , Reusken A.
Published: February 2007

We consider Newton–Krylov methods for solving discretized compressible Euler equations. A good preconditioner in the Krylov subspace method is crucial for the efficiency of the solver. In this paper we consider a point‐block Gauss–Seidel method as preconditioner. We describe and compare renumbering strategies that aim at improving the quality of this preconditioner. A variant of reordering methods known from multigrid for convection‐dominated elliptic problems is introduced. This reordering algorithm is essentially black‐box and significantly improves the robustness and efficiency of the point‐block Gauss–Seidel preconditioner. Results of numerical experiments using the QUADFLOW solver and the PETSc library are given. Copyright © 2007 John Wiley & Sons, Ltd.
The impact of execution delay on the profitability of put‐call‐futures trading strategies—Evidence from Taiwan
Authors: Chiou Jong‐Rong , Hsieh Wen‐Liang Gideon , Lin Yuan‐Yi
Published: February 2007

This study examines the impact of execution delay on the profitability of put‐call‐futures quasi‐arbitrage strategies using trade and quote data in the Taiwanese market. Assuming order execution at the next immediate price following a mispricing signal, the execution of individual components is traced and a substantial delay resulting from the late execution of an option is reported. A fill‐or‐kill strategy that directly restricts such a delay is unsatisfactory because unwinding already acquired positions involves added transaction costs. Ex ante performance is significantly improved for combined strategies that execute the less liquid asset first, while shortening the time before acquisition of the first position. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:361–385, 2007
On inverse carrying charges and spatial arbitrage
Authors: Larson Donald F.
Published: February 2007

A dynamic trader problem under uncertain demand is presented and spatial and temporal arbitrage conditions derived from first‐order conditions. A time‐varying storage premium that explains backwardation and inverse carrying charges independent of risk‐aversion, stockouts, or convenience is developed. Random‐returns and cost‐of‐carry models are expressed as special conditions of the derived model. An applied composite‐error model is estimated using data from the London Metal Exchange's copper contract. Predictions of the model are tested against well‐known alternatives. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:305–336, 2007
Tissue type plasminogen activator induced in rat dorsal horn astrocytes contributes to mechanical hypersensitivity following dorsal root injury
Authors: Kozai Toyoko , Yamanaka Hiroki , Dai Yi , Obata Koichi , Kobayashi Kimiko , Mashimo Takashi , Noguchi Koichi
Published: February 2007

Dorsal root injury is known to induce alteration of the extracellular environment in the spinal cord and synaptic reorganization with degradation of injured primary afferent and sprouting of spared terminal. These changes affect behavioral sensitivity and sometimes lead to neuropathic pain. We have hypothesized that changes in extracellular proteolysis in the dorsal horn is involved in neuroplastic changes in the dorsal horn after nerve injury. Tissue type plasminogen activator (tPA) is a well‐known extracellular serine protease and is involved in the modification of the extracellular matrix, which leads to neuroplastic changes such as long‐term potentiation in the hippocampus. In the present study, we found a marked induction of tPA in activated astrocytes following L4/5 root injury and a resultant increase of proteolytic enzymatic activity in the dorsal horn. We also examined the involvement of tPA activity on mechanical hypersensitivity using a root ligation model which has been used for investigating radiculopathy pain behavior. Intrathecal and continuous administration of tPA inhibitor, tPA‐STOP, suppressed root ligation‐induced mechanical allodynia in a dose‐dependent manner during an early stage of injury (0–4 days). In contrast, the delayed administration of tPA‐STOP during the chronic stage of injury (10 days) did not affect pain behavior. These data suggest an important contribution of astrocytes in the dorsal horn to the pathophysiology of radiculopathy pain, and astrocyte‐derived tPA and the proteolytic activity in the dorsal horn may be one of the essential factors involved in pain following root injury. © 2007 Wiley‐Liss, Inc.
Murine model of Alexander disease: Analysis of GFAP aggregate formation and its pathological significance
Authors: Tanaka Kenji F. , Takebayashi Hirohide , Yamazaki Yoshihiko , Ono Katsuhiko , Naruse Masae , Iwasato Takuji , Itohara Shigeyoshi , Kato Hiroshi , Ikenaka Kazuhiro
Published: February 2007

Alexander disease is caused by a coding mutation in the glial fibrillary acidic protein (GFAP) gene. The pathological hallmark is the formation of cytoplasmic inclusions within astrocytes known as Rosenthal fibers (RFs), which primarily consist of GFAP and several heat shock proteins. The presence of mutant GFAP would appear to be involved in RF formation; however, overproduction of wild type human GFAP in mouse brain also results in RF formation. Here, we investigated the in vivo conditions leading to formation of RF‐like aggregates. We used transgenic mice (mouse GFAP promoter‐human GFAP cDNA with R239H mutation) in which the dosage of the GFAP transgene could be manipulated within the same genetic locus. We found that the presence of mutant GFAP per se was insufficient for aggregate formation. Instead, a 30% increase in GFAP content over that in wild type was also required. GFAP aggregates upregulated endogenous GFAP and nestin gene expression, and intermediate filament structure revealed by immunostaining was fragmented under these conditions. However, overall morphology of astrocytes, including their fine processes, was unaffected. In this transgenic animal model, mice did not show megalencephaly, leukodystrophy, or seizure characteristic of Alexander disease with R239H mutation. Nevertheless, their mortality after kainate challenge was dramatically increased, whereas transgenic mice lacking aggregates exhibited mortality similar to that of wild type mice. These results indicate that the presence of GFAP aggregates containing mutant GFAP is not sufficient to induce a major phenotype of Alexander disease, even though it causes some abnormalities in the mouse. © 2007 Wiley‐Liss, Inc.
Nodal protrusions, increased Schmidt‐Lanterman incisures, and paranodal disorganization are characteristic features of sulfatide‐deficient peripheral nerves
Authors: Hoshi Tomiko , Suzuki Ayaka , Hayashi Shuichiro , Tohyama Koujiro , Hayashi Akiko , Yamaguchi Yoshihide , Takeuchi Kosei , Baba Hiroko
Published: February 2007

Galactocerebroside and sulfatide are two major glycolipids in myelin; however, their independent functions are not fully understood. The absence of these glycolipids causes disruption of paranodal junctions, which separate voltage‐gated Na+ and Shaker‐type K+ channels in the node and juxtaparanode, respectively. In contrast to glial cells in the central nervous system (CNS), myelinating Schwann cells in the peripheral nervous system (PNS) possess characteristic structures, including microvilli and Schmidt‐Lanterman incisures, in addition to paranodal loops. All of these regions are involved in axo–glial interactions. In the present study, we examined cerebroside sulfotransferase‐deficient mice to determine whether sulfatide is essential for axo–glial interactions in these PNS regions. Interestingly, marked axonal protrusions were observed in some of the nodal segments, which often contained abnormally enlarged vesicles, like degenerated mitochondria. Moreover, many transversely cut ends of microvilli surrounded the mutant nodes, suggesting that alignments of the microvilli were disordered. The mutant PNS showed mild elongation of nodal Na+ channel clusters. Even though Caspr and NF155 were completely absent in half of the paranodes, short clusters of these molecules remained in the rest of the paranodal regions. Ultrastructural analysis indicated the presence of transverse bands in some paranodal regions and detachment of the outermost several loops. Furthermore, the numbers of incisures were remarkably increased in the mutant internode. Therefore, these results indicate that sulfatide may play an important role in the PNS, especially in the regions where myelin–axon interactions occur. © 2007 Wiley‐Liss, Inc.
IGF‐1 stimulates de novo fatty acid biosynthesis by Schwann cells during myelination
Authors: Liang Guoying , Cline Gary W. , Macica Carolyn M.
Published: February 2007

Schwann cell (SC) differentiation to the myelinating phenotype is characterized by the elaboration of a lipid‐rich membrane and the expression of myelin‐specific proteins. Insulin‐like growth factor‐1 (IGF‐1) has been identified as a growth factor that stimulates the early events of myelination in SCs that signals via the PI3K/Akt pathway. Given the role of IGF‐1 in promoting myelination, we performed studies to determine if the fatty acid biosynthetic pathway was a target of IGF‐1 signaling in the formation of myelin membrane in dorsal root ganglion neuron/Schwann cell (DRG/SC) cocultures. We report that the fatty acid profile of lipid extracts of cocultures treated with IGF‐1 match that reported for native myelin membrane by electrospray mass spectroscopy analysis. We also demonstrate de novo fatty acid biosynthesis in response to IGF‐1 treatment in DRG/SC cocultures metabolically labeled with 13C‐acetate as a carbon source for fatty acid synthesis. Consistent with this finding, Western blot analysis of lysates from both cocultures and purified SCs reveal that IGF‐1 stimulates two key fatty acid synthesizing enzymes. Additionally, we show that stimulation of fatty acid synthesizing enzymes is mediated by the PI3K/Akt signaling pathway. We also show that the fatty acid synthesizing enzymes and associated signaling pathways are elevated during the period of myelin membrane formation in sciatic nerve. Collectively, these findings demonstrate that IGF‐1 plays an important regulatory function during myelin membrane formation. © 2007 Wiley‐Liss, Inc.
Progressivity in the financing of decentralized government health programs: a decomposition
Authors: Wagstaff Adam , Lindelow Magnus
Published: February 2007

In many countries health services and/or health insurance are delivered but also partly financed by subnational entities that vary in their fiscal or financial capacity, e.g. local governments and social health insurance schemes. The central government typically mandates a specific (or at least minimum) level of benefit or expenditure per intended beneficiary, and sets rules about enrollment and coverage. It also typically contributes to the cost of the program, partly because the resources of subnational entities may be insufficient, on average, to meet the expenditure requirements, but partly for equity reasons. These two problems are typically addressed through tax‐transfer schemes. In practice, there is considerable institutional heterogeneity across countries in the mix of vertical and horizontal schemes, and the way each works. In this Note, we show how the progressivity of health outlays by subnational entities can be decomposed into contributions from vertical and horizontal schemes, and how each of these can be further decomposed into contributions from taxes and transfers. We suggest that, in addition to providing a foundation for future empirical work, the decomposition provides some insights into the reasons for different institutional choices, and into the way vertical and horizontal tax‐transfer schemes operate in practice. Copyright © 2007 John Wiley & Sons, Ltd.
A change detection algorithm for terrain surface moisture mapping based on multi‐year passive microwave remote sensing (Examples of SSM/I and TMI Channels)
Authors: Jin Ya‐Qiu , Yan Fenghua
Published: February 2007

As an indication of the surface polarized emission, a polarization index (PI) of microwave radiance from the terrain surface (half‐space of canopy‐soil land) is derived from the radiative transfer model. This PI separates the radiance effects of the canopy‐soil moisture and interference from surface roughness and atmosphere, and is suitable to describe the change of terrain surface moisture, especially for extreme drought or flood conditions. As an example, the statistics of the monthly average < PI > from 6 years' data of the Defense Meteorological Satellite Program (DMSP) SSM/I observations at the lowest frequency 19·35 GHz channel as available are applied for the demonstration of the surface moisture status over a large and heterogeneous territory such as China. The deviation of the PI data at the same month from the average < PI > , i.e. ΔnPI(≡(PI− < PI>)/ < PI>), gives prominence to focusing moisture variation of terrain surface, and its anomaly shows possible drought or flood occurrence in extreme conditions. The ΔnPI mapping is validated by the typical examples of the drought in China's Shanxi area in May 2001 and the flood around China's Yangtze River in August 1998, respectively. Our approach is recommended for lower frequency channels to minimize the influence from vegetation canopy for future applications (such as the channels of the Advanced Microwave Scanning Radiometer [AMSR‐E] launched in May 2002 and microwave imaging radiometer of China's Fengyun satellite series). When the monthly < PI > and the ground truth of average volumetric moisture < mv > of the region are correctly evaluated, it is tractable to retrieve the soil land surface moisture by using the PI data at the same month and the same region without much knowledge of surface roughness, vegetation canopy and other factors. As an example, the retrieval of mv is favourably tested by using the Tropical Rainfall Measuring Mission (TRMM) Tropical Microwave Imager (TMI) data. Copyright © 2007 John Wiley & Sons, Ltd.
Aromatic‐backbone interactions in model α‐helical peptides
Authors: Palermo Nicholas Y. , Csontos József , Owen Michael C. , Murphy Richard F. , Lovas Sándor
Published: February 2007

The effects on helical stability of weak polar interactions between aromatic side‐chains and the peptide backbone were examined. α‐Helical model peptides, hexa‐Ala, with sequential Tyr replacement, were investigated computationally to obtain the geometries and energetics of the interactions. Geometries were obtained with the B3LYP/6‐31G* level of theory. Interaction energies were calculated using BHandHLYP/cc‐pVTZ and an improved method to correct for basis set superposition error when fragmentation caused steric clashes. Both i, i + 1 and i, i − 4 interactions were observed when Tyr was in position i = 5. The position of the aromatic residue in the amino acid sequence was crucial in facilitating aromatic‐backbone interactions. The distance between the center of the aromatic ring of Tyr and the individual interacting backbone atoms ranged from 3.65 to 5.50 Å. The interactions have energies of the same order as hydrogen bonds and, thus, could have a significant impact on the stability of the helix. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007