bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of RNA folding measures
Authors: Freyhult Eva , Gardner Paul P , Moulton Vincent
Published: October 2005

Background

In the last few decades there has been a great deal of discussion concerning whether or not noncoding RNA sequences (ncRNAs) fold in a more well-defined manner than random sequences. In this paper, we investigate several existing measures for how well an RNA sequence folds, and compare the behaviour of these measures over a large range of Rfam ncRNA families. Such measures can be useful in, for example, identifying novel ncRNAs, and indicating the presence of alternate RNA foldings.

Results

Our analysis shows that ncRNAs, but not mRNAs, in general have lower minimal free energy (MFE) than random sequences with the same dinucleotide frequency. Moreover, even when the MFE is significant, many ncRNAs appear to not have a unique fold, but rather several alternative folds, at least when folded in silico. Furthermore, we find that the six investigated measures are correlated to varying degrees.

Conclusion

Due to the correlations between the different measures we find that it is sufficient to use only two of them in RNA folding studies, one to test if the sequence in question has lower energy than a random sequence with the same dinucleotide frequency (the Z-score) and the other to see if the sequence has a unique fold (the average base-pair distance, D).
Clustering protein sequences with a novel metric transformed from sequence similarity scores and sequence alignments with neural networks
Authors: Ma Qicheng , Chirn Gung-Wei , Cai Richard , Szustakowski Joseph D , Nirmala NR
Published: October 2005

Background

The sequencing of the human genome has enabled us to access a comprehensive list of genes (both experimental and predicted) for further analysis. While a majority of the approximately 30000 known and predicted human coding genes are characterized and have been assigned at least one function, there remains a fair number of genes (about 12000) for which no annotation has been made. The recent sequencing of other genomes has provided us with a huge amount of auxiliary sequence data which could help in the characterization of the human genes. Clustering these sequences into families is one of the first steps to perform comparative studies across several genomes.

Results

Here we report a novel clustering algorithm (CLUGEN) that has been used to cluster sequences of experimentally verified and predicted proteins from all sequenced genomes using a novel distance metric which is a neural network score between a pair of protein sequences. This distance metric is based on the pairwise sequence similarity score and the similarity between their domain structures. The distance metric is the probability that a pair of protein sequences are of the same Interpro family/domain, which facilitates the modelling of transitive homology closure to detect remote homologues. The hierarchical average clustering method is applied with the new distance metric.

Conclusion

Benchmarking studies of our algorithm versus those reported in the literature shows that our algorithm provides clustering results with lower false positive and false negative rates. The clustering algorithm is applied to cluster several eukaryotic genomes and several dozens of prokaryotic genomes.
Nymphal RNAi: systemic RNAi mediated gene knockdown in juvenile grasshopper
Authors: Dong Ying , Friedrich Markus
Published: October 2005

Background

Grasshopper serves as important model system in neuroscience, development and evolution. Representatives of this primitive insect group are also highly relevant targets of pest control efforts. Unfortunately, the lack of genetics or gene specific molecular manipulation imposes major limitations to the study of grasshopper biology.

Results

We investigated whether juvenile instars of the grasshopper species Schistocerca americana are conducive to gene silencing via the systemic RNAi pathway. Injection of dsRNA corresponding to the eye colour gene vermilion into first instar nymphs triggered suppression of ommochrome formation in the eye lasting through two instars equivalent to 10–14 days in absolute time. QRT-PCR analysis revealed a two fold decrease of target transcript levels in affected animals. Control injections of EGFP dsRNA did not result in detectable phenotypic changes. RT-PCR and in situ hybridization detected ubiquitous expression of the grasshopper homolog of the dsRNA channel protein gene sid-1 in embryos, nymphs and adults.

Conclusion

Our results demonstrate that systemic dsRNA application elicits specific and long-term gene silencing in juvenile grasshopper instars. The conservation of systemic RNAi in the grasshopper suggests that this pathway can be exploited for gene specific manipulation of juvenile and adult instars in a wide range of primitive insects.
Survey of Australians using cannabis for medical purposes
Authors: Swift Wendy , Gates Peter , Dillon Paul
Published: October 2005

Background

The New South Wales State Government recently proposed a trial of the medical use of cannabis. Australians who currently use cannabis medicinally do so illegally and without assurances of quality control. Given the dearth of local information on this issue, this study explored the experiences of medical cannabis users.

Methods

Australian adults who had used cannabis for medical purposes were recruited using media stories. A total of 147 respondents were screened by phone and anonymous questionnaires were mailed, to be returned by postage paid envelope.

Results

Data were available for 128 participants. Long term and regular medical cannabis use was frequently reported for multiple medical conditions including chronic pain (57%), depression (56%), arthritis (35%), persistent nausea (27%) and weight loss (26%). Cannabis was perceived to provide "great relief" overall (86%), and substantial relief of specific symptoms such as pain, nausea and insomnia. It was also typically perceived as superior to other medications in terms of undesirable effects, and the extent of relief provided. However, nearly one half (41%) experienced conditions or symptoms that were not helped by its use. The most prevalent concerns related to its illegality. Participants reported strong support for their use from clinicians and family. There was almost universal interest (89%) in participating in a clinical trial of medical cannabis, and strong support (79%) for investigating alternative delivery methods.

Conclusion

Australian medical cannabis users are risking legal ramifications, but consistent with users elsewhere, claim moderate to substantial benefits from its use in the management of their medical condition. In addition to strong public support, medical cannabis users show strong interest in clinical cannabis research, including the investigation of alternative delivery methods.
Re-Treatment With I-131 Tositumomab in Patients With Non-Hodgkin's Lymphoma Who Had Previously Responded to I-131 Tositumomab
Authors: Kaminski Mark S. , Radford John A. , Gregory Stephanie A. , Leonard John P. , Knox Susan J. , Kroll Stewart , Wahl Richard L.
Published: October 2005

Purpose

To study efficacy and safety of re-treatment with I-131 tositumomab in patients with low-grade, follicular, or transformed low-grade B-cell lymphoma who relapsed following a response to I-131 tositumomab.

Patients and Methods

A prior response ≥ 3 months to I-131 tositumomab was required. The single therapeutic dose following a dosimetric dose was adjusted to give the same total body dose (in Gy) as that used for the original dose, or was attenuated if the platelet count was less than 150,000 per mm3 or if the prior treatment resulted in grade 4 cytopenias lasting longer than 7 days.

Results

Of 32 patients enrolled, 28 completed the therapeutic dose. A median of four therapies were given before re-treatment. Eighteen (56%) of 32 patients had a complete or partial response (median duration, 15.2 months); eight (25%) had a complete response (median duration, 35 months). Five continue in response from 1.8 to 5.7 years, with a median follow-up of 35 months. The overall median response duration was not significantly different for the two treatments, with no clinical factors predicting response or its duration. Ten of 18 re-responders had longer responses with re-treatment, with five having responses ≥ 1.5 years longer. Grade 3/4 neutropenia and thrombocytopenia occurred in 50% and 43% of patients, respectively, similar to initial treatment. Antimouse antibodies developed in 10% of patients, and 12% developed elevated serum thyroid-stimulating hormone. Six patients were diagnosed with second malignancies, including four patients who developed myelodysplastic syndrome (one who had not received the therapeutic dose) and one with acute myelogenous leukemia.

Conclusion

Re-treatment with I-131 tositumomab following a previous response can produce second responses that can be durable.
Cell Therapy of Stage IV Nasopharyngeal Carcinoma With Autologous Epstein-Barr Virus–Targeted Cytotoxic T Lymphocytes
Authors: Comoli Patrizia , Pedrazzoli Paolo , Maccario Rita , Basso Sabrina , Carminati Ornella , Labirio Massimo , Schiavo Roberta , Secondino Simona , Frasson Chiara , Perotti Cesare , Moroni Mauro , Locatelli Franco , Siena Salvatore
Published: October 2005

Purpose

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV) –related malignancy expressing EBV antigens that are possible targets of cell therapy, including latent membrane protein 2 (LMP2). We conducted a clinical trial of EBV-targeted cell therapy with autologous virus-specific cytotoxic T lymphocytes (CTLs) for NPC refractory to conventional treatments.

Patients and Methods

Ten patients with EBV-related stage IV NPC in progression after conventional radiotherapy and chemotherapy received intravenously autologous EBV-specific CTLs reactivated and expanded ex vivo from peripheral blood lymphocytes through stimulation with EBV-transformed autologous B-lymphoblastoid cell lines (LCL). Toxicity, specific cellular immune responses, and clinical tumor responses were evaluated.

Results

EBV-specific CTLs could be generated in all patients and were predominantly CD3+/CD8+ T lymphocytes displaying specific killing of autologous EBV-LCL, autologous NPC cells as well as autologous targets bearing the EBV antigen LMP2. Patients received two to 23 infusions of EBV-specific CTLs that were well tolerated with the exception of grade 1 to 2 inflammatory reactions at the tumor site in two cases. Control of disease progression was obtained in six of 10 patients (two with partial response and four with stable disease). Analysis of interferon-γ–producing cells demonstrated an increased frequency of EBV-specific immunity, with appearance of LMP2-specific responses in four patients, of whom three had clinical benefit.

Conclusion

Cell therapy with EBV-targeted autologous CTLs is safe, induces LMP-2-specific immunologic responses, and is associated with objective responses and control of disease progression in patients with stage IV NPC resistant to conventional treatments.
Deepening and Extending the Quantum Principles in Chemistry
Authors: Nakatsuji Hiroshi
Published: October 2005

A brief summary of the author’s research projects for deepening and extending the quantum principles in chemistry is given. First, the structure of the exact wave function that is the solution of the Schrödinger equation was clarified and a method of calculating it starting from an approximate wave function is given. The singularity problem intrinsic to atoms and molecules was overcome, and a general method of solving the Schrödinger equation in an analytical form has been established. Quantum chemistry of excited states and ionized states is essential since it is difficult with experiments alone to explore this field due to the short lives of these species. The SAC-CI theory developed in the author’s groups offers a powerful method for investigating the chemistry of excited and ionized states. The energy gradient method incorporated into this program is particularly useful for studying geometries and reactions involving these states. The catalysis on a metal surface is a magic process that must be clarified with the help of quantum theory. The author studied it using his dipped adcluster model (DAM) that includes the effects of the free electrons of the bulk metal. The epoxidation reactions of ethylene and propylene were studied with this method. The NMR chemical shifts include much information about the valence electrons of molecular systems. The author clarified that the major electronic mechanisms of the chemical shifts could be attributed to the intrinsic atomic properties that are related to the position of the element in the periodic table. For the chemical shifts induced by heavy ligands, the relativistic effect is sometimes dominant. The spin-orbit effect is most important for light resonant nuclei. For heavier resonant nuclei, other spin-free relativistic effects and the electron correlation effects are also important and they strongly couple with each other, implying an existence of something “unexpected” in the chemistry of heavy elements. Finally, the strategy of the author’s study in quantum chemistry is shortly described.
Synthetic Strategy for Rational Design of Single-Chain Magnets
Authors: Miyasaka Hitoshi , Clérac Rodolphe
Published: October 2005

A magnetically-isolated one-dimensional chain can behave as if “magnet”— this sentence may be opposed to our common sense. In this review, we will show that a “magnet-like” behavior can effectively be found in only a magnetic spin chain. In 2001, which is almost forty years after the pioneering theoretical work of R. J. Glauber [J. Math. Phys., 4, 294 (1963)] on the dynamics of ferromagnetically-coupled Ising spin chains, the first experimental evidence of such behavior has been discovered in a real one-dimensional compound [A. Caneschi et al. Angew. Chem., Int. Ed., 40, 1760 (2001)]. In 2002, we have reported on a one-dimensional compound [Mn2(saltmen)2Ni(pao)2(py)2](ClO4)2 (saltmen2− = N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminato), pao− = pyridine-2-aldoximato, and py = pyridine) which can be considered as a chain of ferromagnetically-coupled anisotropic ST = 3 units [J. Am. Chem. Soc., 124, 12837 (2002)]. Magnetic measurements on this compound revealed the presence of slow relaxation and large field-dependent hysteresis of the magnetization at low temperatures. The topology of this chain is very close to the “ideal” chain imagined by Glauber and hence, still to date, the simplest system to probe the Glauber dynamics. By analogy to the Single-Molecule Magnets described in the introduction of this paper, we called this type of material: Single-Chain Magnet (SCM). To obtain simple SCM systems, we have developed a step-by-step synthetic strategy using primary and secondary building blocks to control the chemistry of the targeting materials and the physics of their characteristic magnetic properties. In this review, we will describe this synthetic strategy from the elementary building blocks to the final series of Single-Chain Magnets obtained since 2002. The magnetic properties of all these materials will be discussed in detail. In particular, the experimental SCM behavior will be described and analyzed in relation with the generalization of the Glauber model for real systems.
Design and Synthesis of Semi-Artificial Myoglobin Possessing DNA-Binding Peptides on Heme Propionates
Authors: Sakamoto Seiji , Kudo Kazuaki
Published: October 2005

Peptides possessing the DNA-binding capability were successfully introduced into myoglobin by a cofactor-reconstitution strategy. We have designed and synthesized an artificial iron–protoporphyrin IX (heme)–peptide conjugate, Heme(br)2, which has covalently conjugated GCN4 basic region peptides at the heme propionate groups as an artificial DNA-binding site. The peptide Heme(br)2 was inserted into apomyoglobin to give a peptide-conjugated myoglobin, Mb(br)2. The UV–vis and circular dichroism spectra of Mb(br)2 were comparable to those of native myoglobin, suggesting that the heme environment and three-dimensional structure of Mb(br)2 were almost identical to those of native myoglobin. The size exclusion chromatography indicated that the Mb(br)2 existed as a monomeric form in an aqueous solution and interacted with its target DNA sequence [c-AMP responsive element (CRE)]. The fluorescence study also revealed that the Mb(br)2 bound CRE DNA effectively with 1/1 stoichiometry [affinity constant; 8.4 (±0.8) × 107 M−1]. Additionally, the CRE DNA-binding enhanced the peroxidase-like activity of Mb(br)2, possibly due to the partial structural perturbation around the heme active-site. These results demonstrate that the chemical modification of prosthetic group with functional peptides can provide a new strategy for the design of semi-artificial proteins with engineered function.
Gold Nanoparticles Stabilized by Tripod Thioether Oligomers: Synthesis and Molecular Dynamics Studies
Authors: Hosokawa Youichi , Maki Suguru , Nagata Toshi
Published: October 2005

Gold nanoparticles (1.5–1.7 nm) were prepared by use of three tripod thioether oligomers as stabilizing molecules. The particle sizes were independent of the sizes of the stabilizers, and were smaller than those stabilized with simpler thioethers. Molecular dynamics simulations were performed to examine how the stabilizers adsorb on the nanoparticles. Parameters were developed for modeling the interactions between gold and organic molecules. Simulations in explicit chloroform solvent at 300 K revealed multiple-point adsorption of the stabilizers on the nanoparticles.
Electrocatalytic Reduction of Dioxygen on 9,10-Anthraquinones-Incorporated Clay-Modified Glassy Carbon Electrodes
Authors: Manisankar Paramasivam , Gomathi Anandhan
Published: October 2005

The preparation and electrochemical characterization of 9,10-anthraquinones adsorbed clay-modified and anthraquinones–clay composite-modified glassy carbon electrodes (GCEs) were investigated. The influence of the pH on the electrochemical behavior and stability of the clay-modified electrodes (CMEs) were studied by cyclic voltammetry in acidic and neutral aqueous media. For the dioxygen reduction, anthraquinones adsorbed clay-modified electrodes possess good electrocatalytic abilities with overpotential ranging from 174 to 452 mV, lower than the bare GCE in the pH range 4.0–7.0; also, anthraquinones–clay composite-modified electrodes exhibited potent catalytic activities with an overpotential of about 128–421 mV lower than at a bare GCE at pH 7.0–8.0. The diffusion coefficients of mediators in clay films were evaluated by chronoamperometric techniques. Chronocoulometric studies showed the involvement of two electrons in the reduction of anthraquinones and four electrons in dioxygen reduction at the optimum pH. In addition, hydrodynamic voltammetric studies were performed to determine the mass-specific activity of the anthraquinones used, the heterogeneous rate constants for the reduction of O2 at the surface of modified electrodes and the apparent diffusion coefficient of O2 in aqueous O2-saturated buffer solutions.
Mass Spectrometric and Spectroscopic Studies on Hydrolysis of Phosphoesters by Bis(μ-acetato)-μ-phenolato Dinuclear Metal(II) Complexes (Metal = Mn, Co, Ni, and Zn)
Authors: Jikido Reiko , Shiraishi Hitomi , Matsufuji Kanako , Ohba Masaaki , Furutachi Hideki , Suzuki Masatatsu , Okawa Hisashi
Published: October 2005

Dinuclear metal(II) complexes of 2,6-bis{N-[(2-dimethylamino)ethyl]iminomethyl}-4-methylphenol (HL), [Mn2(L)(AcO)2(NCS)] (1), [Co2(L)(AcO)2]BPh4 (2), [Ni2(L)(AcO)2(MeOH)]BPh4 (3), and [Zn2(L)(AcO)2]BPh4 (4), have been examined as regards their hydrolytic activity toward tris(p-nitrophenyl) phosphate (TNP) and hydrogen bis(p-nitrophenyl) phosphate (HBNP) by means of mass spectrometric methods as well as UV–visible spectroscopic methods. All the complexes hydrolyze TNP to BNP− in the relative activity of 4 > 2 > 1 >> 3. It is found that one AcO− group of [M2(L)(AcO)2]+ is replaced with BNP−, arising from the hydrolysis of TNP, affording [M2(L)(AcO)(bnp)]+ in an equilibrium with [M2(L)(AcO)2]+: [M2(L)(AcO)2]+ + BNP− [M2(L)(AcO)(bnp)]+ + AcO−. In the reaction of HBNP with 1–4, [M2(L)(AcO)(bnp)]+ is produced in the equilibrium with [M2(L)(AcO)2]+, and the bound BNP− is slowly hydrolyzed in the case of M = Mn and Co. The bound BNP− of [Ni2(L)(AcO)(bnp)]+ is barely hydrolyzed and the bound BNP− of [Zn2(L)(AcO)(bnp)]+ is practically not hydrolyzed. The relevance of the complexes to phosphotriesterase and phosphodiesterase is discussed.
Comparison of 8-Quinolinol Derivatives as Carriers for the Collection of Heavy Metals with Emulsion Globules
Authors: Matsumiya Hiroaki , Ohkouchi Ryohei , Hiraide Masataka
Published: October 2005

A series of 8-quinolinol derivatives has been examined as carriers for the collection of heavy metals with water-in-oil emulsion globules. The emulsion was prepared by dissolving 50 μmol of 8-quinolinol derivative and 30 mg of Span-80 (sorbitan monooleate) in 2.0 cm3 of toluene and vigorously mixing with 0.50 cm3 of 1.0 mol dm−3 hydrochloric acid by ultrasonic irradiation. The resulting emulsion was gradually injected into 25 cm3 of sample solution [containing 0.10 μg each of Fe(III), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II)] at pH 4–8 and dispersed by stirring for 10 min as numerous tiny globules. When working with the parent compound, 8-quinolinol, Fe(III), Co(II), Ni(II), Cu(II), and Cd(II) were effectively transported through the toluene layer into the internal aqueous phase of the emulsion. However, Pb(II) was not transported at all. The derivatives of 5,7-dichloro-, 2-methyl-, and 5-octyloxymethyl-8-quinolinol were not useful for the simultaneous collection of the heavy metals. On the other hand, Kelex-100 (7-dodecenyl-8-quinolinol) allowed a nearly quantitative (more than 90%) collection of all the metals at pH 7–8. The effects of the substituents on the metal-collection efficiency are discussed in terms of the acidity and hydrophobicity of the carriers.
μ-Hydroxo-μ-phenolato Dinuclear Nickel(II) Complexes in a Mixed-Spin State and Their Urea Adduct as Relevance to the Urease Active Site
Authors: Amase Rie , Shiraishi Hitomi , Miyasato Yuji , Ohba Masaaki , Okawa Hisashi
Published: October 2005

Dinucleating compartmental ligands (2,6-bis{N-[(2-dimethylamino)ethyl]iminomethyl}-4-methylphenol (HL1) and 2-{N-[(2-dimethylamino)ethyl]iminomethyl}-6-{N-methyl-N-[2-(dimethylamino)ethyl]aminomethyl}-4-methylphenol (HL2)) have afforded the following dinuclear nickel(II) complexes: [Ni2(L1)(OH)(py)(H2O)](ClO4)2·H2O (1), [Ni2(L2)(OH)(MeOH)(H2O)](ClO4)2·CH3CN (2), and [Ni2(L2)(OH)(dmf)2](ClO4)2 (3). X-ray crystallographic studies for 1 and 3 have clarified a μ-hydroxo-μ-phenolato dinuclear structure in a mixed-spin state with one pseudo octahedral Ni(II) (S = 1) and one planar Ni(II) (S = 0). The urea adducts, [Ni2(L1)(OH)(urea)(H2O)](ClO4)2·H2O (1′) and [Ni2(L2)(OH)(urea)(H2O)](ClO4)2 (2′), were prepared by the reaction of 1 and 2 with urea, respectively, and were structurally characterized to be in the mixed-spin state. The relevance of 1′ and 2′ to urease is discussed.
The Yukawa–Tsuno Relationship for the β-Silicon Effect in the Solvolysis Rates of 2-(Aryldimethylsilyl)ethyl Chlorides
Authors: Fujio Mizue , Uchida Mai , Okada Ayumi , Alam Md Ashadul , Fujiyama Ryoji , Siehl Hans-Ullrich , Tsuno Yuho
Published: October 2005

Solvolysis rates of 2-(aryldimethylsilyl)ethyl chlorides were determined conductimetrically in 60% (v/v) aqueous ethanol. The effects of aryl substituents at the silyl atom on the solvolysis rates at 50 °C were correlated with essentially nonresonant parameters of r = 0.10 in terms of Yukawa–Tsuno (Y–T) Eq. 1, giving a ρ value of −1.75. Such a high ρ value may be regarded as the effect of aryl ring on the bridged Si in the rate-determining step. The Si-bridging is consistent with the fact that the solvolysis of the unsubstituted substrate with d2-labeled ethylene moiety gave substitution products with label scrambling. The arylsilyl substituent effects were likewise analyzed for several relevant sets of β-silyl systems in order to ascertain significant variations of ρ values from system to system; Y–T Eq. 1 correlated quite excellently with essentially nonresonant sigmas of negligible resonance demand (r 0.10), to exhibit significant variations of ρ from −1.75 to −0.95.
Photocontrol of Micelle Triggered by Malachite Green Carrying a Long Alkyl Chain
Authors: M. Uda Ryoko , Kimura Keiichi
Published: October 2005

A Malachite Green derivative carrying a long alkyl chain has been designed to realize the photoinduced uptake of oily substances based on its photogenerated amphiphilicity. NMR spectroscopy was used to evaluate the solubility of benzene in cetyltrimethylammoium chloride solution with Malachite Green carrying a long alkyl chain. We found that UV irradiation drastically increased the solubility of benzene in the system of Malachite Green carrying a long alkyl chain. The results for the photoinduced solubilization are in good agreement with the photoionization ratio of Malachite Green carrying a long alkyl chain, which can play an important role in the control of molecular assemblies.
Copolymerization of Ethylene with Methylenecyclopropanes Promoted by Cobalt and Nickel Complexes
Authors: Takeuchi Daisuke , Anada Kouhei , Osakada Kohtaro
Published: October 2005

The cobalt and nickel complexes promote addition polymerization of substituted methylenecyclopropanes as well as their copolymerization with ethylene to afford the polymers that contain three-membered rings. The homopolymerization of 2-aryl-1-methylenecyclopropane catalyzed by [CoCl2(L)]–MMAO (L = bis(1-iminoalkyl)pyridine ligand) at −40 °C produces the polymers with a narrow molecular weight distribution. The copolymer of ethylene and 2-aryl-1-methylenecyclopropane is also obtained by using the same catalyst. The ratio of the two monomer units varies in the range from 0 to 0.5 depending on the concentration of ethylene and 2-aryl-1-methylenecyclopropane. 13C{1H} NMR spectrum of the alternating copolymer exhibits a single sharp signal for each carbon of the repeating units. Ethylene and 7-methylenebicyclo[4.1.0]heptane also undergo alternating copolymerization to produce the polymer having the C4 repeating unit containing a bicyclic group. Heating the polymer at 130 °C causes ring-opening isomerization to afford the polymer having a C=C double bond in the main chain. Mixtures of [Ni(π-C3H5)Br]2, a diimine ligand, and cocatalysts such as NaBARF and Et2AlCl, initiate the copolymerization of ethylene with 2-aryl-1-methylenecyclopropane to give a random copolymer with a low molecular weight (Mn = 1000–2000).
Threadlike Micelles Controlling Viscosities of Cement Slurry
Authors: Yamamuro Hotaka , Koyanagi Koji , Takahashi Hiromichi
Published: October 2005

The threadlike micelle of a cationic surfactant: cetyltrimethylammonium chloride (CTAC), containing anionic aromatic substances has been formed with unique rheological properties in strong electrolyte aqueous solutions and slurry using an inorganic powder such as cement. The threadlike micelle can be used as a high-efficiency viscosity agent for cement slurry.
Identification of Fentanyl, Alfentanil, Sufentanil, Remifentanil and Their Major Metabolites in Human Urine by Liquid Chromatography/Tandem Mass Spectrometry for Doping Control Purposes
Authors: Thevis Mario , Geyer Hans , Bahr Daniel , Schänzer Wilhelm
Published: October 2005

Since January 2005, the list of prohibited substances established by the World Anti-Doping Agency prohibits the opioid agent fentanyl as well as its related drugs in professional and amateur sports. Fast, reliable and robust analytical assays are required that allow the sensitive determination of these compounds or respective metabolites in human urine and liquid chromatography interfaced to mass spectrometry has proven to be a suitable and powerful tool for drug testing for several years. A screening and confirmation method was developed that enables the identification of fentanyl, alfentanil, remifentanil and sufentanil as well as their N-dealkylated or de-esterified metabolites utilizing solid-phase extraction of a 2 mL urine aliquot followed by LC-electro-spray-MS/MS analysis. The procedure was validated in terms of recovery (95.8–104.9%), lower limit of detection (0.5 ng mL−1), specificity and interday precision (3.9–19.8%) for the four opioid drugs and the metabolic product norfentanyl. In addition, the mass spectrometric behavior of fentanyl after electrospray ionization and collision-induced dissociation was studied by synthesis and analysis of structurally related compounds and dissociation pathways were proposed allowing the characterization of target analytes and corresponding metabolites.
Electron-Impact Ionization of Mandelic Acid and Mandelic Acid Methyl Ester as Prototypes for the C6H5CH(OH)-X System: Ionization and Appearance Energies, Activation Energies and Enthalpies of Formation
Authors: Opitz Joachim
Published: October 2005

Electron-impact ionization mass spectra, the decay of metastable ions, ionization and appearance energies and bond energies, as dissociation energies, are reported for mandelic acid (MA) and mandelic acid methyl ester (MAME) . An ionization energy of 8.55 eV was obtained for both compounds. For the formation of C6H5+ ions, appearance energies of 14.25 eV or 14.40 eV were determined for MA or MAME, respectively. On the main fragmentation route from molecular ions to these C6H5+ ions, an activation energy of (1.1±0.1)eV in excess of the calculated total reaction enthalpy was found for the elimination of CO from the prominent C7H7O+ ions to C6H7+ ions, involving the transfer of two H-atoms. The second (minor) fragmentation route via C7H6O+ions resembles the benzaldehyde decomposition pathway and the individual steps were found to be near to their calculated thermochemical reaction enthalpies. Gas-phase enthalpies of formation of (–4.652±0.3 eV) [≡ (–448.8±30) kJ mol−1] for MA and (–4.243±0.3) eV [≡ (–409.4±30) kJ mol−1] for MAME are derived, based on the appearance energy of their C7H7O+ ions at m/z 107 and the formation enthalpy adopted from protonated benzaldehyde. The results are compared with data for benzylalcohol.
Gas-Phase Chemistry of the Negative Ions of Fully-Protected Peptides by High-Resolution Electrospray Ionization Tandem Mass Spectrometry
Authors: Napoli Anna , Di Donna Leonardo , Sindona Giovanni , Urso Elena
Published: October 2005

Fully-protected C-terminal free peptides can be conveniently analyzed by high-resolution electrospray tandem mass spectrometry (ESI-MS/MS) in a quadrupole quadrupole time-of-flight tandem hybrid mass spectrometer, operated in the negative (–) ionization mode. The unusual choice of negative ions in mass spectrometry applications to peptide analysis was needed to obtain exhaustive sequence and structural data. The low-energy collision-induced dissociation (CID) experiments provided, in fact, tandem mass spectra displaying highly diagnostic fragments with a good signal-to-noise ratio. The method is applied to segments of porcine calcitonin (Cal), Cal (10–16, 1), Cal (17–24, 2) and Cal (25–28, 3) whose [M–H]− deprotonated molecular ions provided low-energy CID mass spectra which allow the evaluation either of the primary structure of the peptide and of the location of the side-chain protective groups. ESI (+) MS can be conveniently used, in the high resolution mode, to achieve precise information on the elemental composition of the examined peptides.
Studies on the Mechanism of the Hoesch Reaction and its Modified Reaction with Low-Temperature Mass Spectrometry
Authors: Li Shaobai , Li Yuqi , Zheng Hongyan
Published: October 2005

The original Hoesch reaction was modified by employing a mixture of HZnCl2(OH) and ZnCl2 as the catalyst for the preparation of [Formula: see text] compound 4. Total synthesis of the natural product, Coccineone B, was achieved using compound 4 as a key intermediate. A low-temperature mass spectrometry technique was used to clarify the mechanism of the Hoesch reaction through the easy and exact identification of isotopic clusters.
Overchoice and Assortment Type: When and Why Variety Backfires
Authors: Gourville John T. , Soman Dilip
Published: October 2005

Almost universally, research and practice suggest that a brand that increases its product assortment, or variety, should benefit through increased market share. In this paper, we show this is not always the case. We introduce the construct “assortment type” and demonstrate that the effect of assortment size on brand share is systematically moderated by assortment type. We define an “alignable” assortment as a set of brand variants that differ along a single, compensatory dimension such that choosing from that assortment only requires within-attribute trade-offs. In contrast, we define a “nonalignable” assortment as a set of brand variants that simultaneously vary along multiple, noncompensatory dimensions, demanding between-attribute trade-offs. In turn, we argue that an alignable assortment can efficiently meet the diverse tastes of consumers, thereby increasing brand share, but that a nonalignable assortment increases both the cognitive effort and the potential for regret faced by a consumer, thereby decreasing brand share. We term this effect “overchoice.”

Across three studies, we provide evidence of overchoice and tie the effect to the effort and regret brought about by nonalignability. In the process, we demonstrate that simplification of information presentation, reversibility of choice, and a reduction in underlying nonalignability serve to reduce or eliminate this effect.
The Targeting of Advertising
Authors: Iyer Ganesh , Soberman David , Villas-Boas J. Miguel
Published: October 2005

An important question that firms face in advertising is developing effective media strategy. Major improvements in the quality of consumer information and the growth of targeted media vehicles allow firms to precisely target advertising to consumer segments within a market. This paper examines advertising strategy when competing firms can target advertising to different groups of consumers within a market. With targeted advertising, we find that firms advertise more to consumers who have a strong preference for their product than to comparison shoppers who can be attracted to the competition. Advertising less to comparison shoppers can be seen as a way for firms to endogenously increase differentiation in the market. In addition, targeting allows the firm to eliminate “wasted” advertising to consumers whose preferences do not match a product’s attributes. As a result, the targeting of advertising increases equilibrium profits. The model demonstrates how advertising strategies are affected by firms being able to target pricing. Target advertising leads to higher profits, regardless of whether or not the firms have the ability to set targeted prices, and the targeting of advertising can be more valuable for firms in a competitive environment than the ability to target pricing.
Practice Prize Article—CHAN4CAST: A Multichannel, Multiregion Sales Forecasting Model and Decision Support System for Consumer Packaged Goods
Authors: Divakar Suresh , Ratchford Brian T. , Shankar Venkatesh
Published: October 2005

We discuss the development and implementation of CHAN4CAST, a sales forecasting model, by pack size, category, channel, region, customer account and a Web-based decision support system (DSS) for consumer packaged goods. In addition to capturing the effects of such variables as past sales, trend, own and competitor prices and promotional variables, and seasonality, the model accounts for the effects of temperature, significant holidays, new product introductions, trading day corrections, and adjustments to the wholesale level. In general, the model forecasts sales volume satisfactorily for a leading consumer packaged goods company. The DSS enables top- and mid-level executives in sales, marketing, strategic planning, and finance to develop accurate forecasts of sales volume, plan prices, and promotional activities over a long time horizon; to track sales response to marketing actions over time; and to simulate forecast scenarios based on possible marketing decisions and other variables. CHAN4CAST is being rolled out for more users and more divisions in the company. The key take-aways are that successful development and implementation of a rigorous marketing science model require a strong internal champion, a careful balance between modeling sophistication and practical relevance, good diagnostic features, regular validations, and greater attention to the development of a fast and responsive DSS.
Post-soul futurama: African American cultural politics and early Detroit techno
Authors: Albiez Sean
Published: October 2005

Techno is a globally successful genre of electronic dance music that can trace its origins to Detroit in the early 1980s, but it has been generally overlooked in academic, historical and critical analyses of 1980s African American music in the United States. This study will consider
the cultural context of early techno, its relationship to European electronic music, the birth of the ‘techno’ genre in the UK, the founding myths and histories of techno, and its potential for helping us understand transformations in African American cultural politics in the ‘postsoul’
era.
An Integrated Model for Bidding Behavior in Internet Auctions: Whether, Who, When, and how Much
Authors: Park Young-Hoon , Bradlow Eric T.
Published: October 2005

The authors develop a general parametric modeling framework for bidding behavior in Internet auctions. Toward this end, they incorporate four key components of the bidding process under their framework: whether people bid on an auction, (if so) who bids, when they bid, and how much they bid over the entire sequence of bids in an auction. This integrated framework is based on a single, latent, time-varying construct of consumer willingness to bid, which bidders have and update for a particular auction item over the course of the auction duration. Using a database of notebook auctions from one of the largest Internet auction sites in Korea, the authors demonstrate that this general (yet parsimonious) model captures the key behavioral aspects of bidding behavior. Furthermore, the authors provide a valuable tool for managers at auction sites to conduct their customer relationship management efforts, which require them to evaluate the ”goodness” of the listed auction items (whether people bid) and the goodness of the potential bidders (who bids, when they bid, and how much they bid).
An Empirical Analysis of Price Discrimination Mechanisms and Retailer Profitability
Authors: Khan Romana J. , Jain Dipak C.
Published: October 2005

Retailers typically engage in some form of price discrimination to increase profitability. In this article, the authors compare the impact on retailer profitability of two price discrimination mechanisms: quantity discounts based on package size (second-degree price discrimination) and store-level pricing or micromarketing (third-degree price discrimination). Whereas the latter has been well addressed in the marketing literature, there is limited empirical research on the use of quantity discounts for price discrimination. Using store-level sales data, the authors estimate a structural demand model, accounting for parameter heterogeneity and price endogeneity. They combine the parameter estimates with a model of retailer pricing to conduct optimal pricing and profitability simulations under several scenarios, ranging from constraining the retailer not to engage in any form of price discrimination to the least restrictive scenario of setting nonlinear price schedules specific to each store. The pricing simulations enable the decomposition of profitability as a result of the different forms of price discrimination. Profits are greatest when retailers combine second- and third-degree price discrimination. The authors find that the ability to engage in second-degree price discrimination contributes more to retailer profitability than does third-degree price discrimination.
Highly Structured AsianDrosophila melanogasterPopulations: A New Tool for Hitchhiking Mapping?
Authors: Schlötterer Christian , Neumeier Hannah , Sousa Carla , Nolte Viola
Published: October 2005

Mark-recapture experiments showed that D. melanogaster has high dispersal capabilities. Consistent with a highly migratory species, only very low levels of differentiation were described for D. melanogaster populations from the same continent. We reinvestigated the population structure in D. melanogaster using 49 polymorphic markers in 23 natural populations. While European and American D. melanogaster populations showed very low differentiation, Asian D. melanogaster populations were highly structured. Despite the high differentiation of Asian flies, we confirm that all non-African populations are derived from a single colonization event. We propose that the availability of D. melanogaster populations with high and low population structure provides a novel tool for the identification of ecologically important adaptations by hitchhiking mapping.
Interactions of UNC-34 Enabled With Rac GTPases and the NIK Kinase MIG-15 in Caenorhabditis elegans Axon Pathfinding and Neuronal Migration
Authors: Shakir M Afaq , Gill Jason S , Lundquist Erik A
Published: October 2005

Many genes that affect axon pathfinding and cell migration have been identified. Mechanisms by which these genes and the molecules they encode interact with one another in pathways and networks to control developmental events are unclear. Rac GTPases, the cytoskeletal signaling molecule Enabled, and NIK kinase have all been implicated in regulating axon pathfinding and cell migration. Here we present evidence that, in Caenorhabditis elegans, three Rac GTPases, CED-10, RAC-2, and MIG-2, define three redundant pathways that each control axon pathfinding, and that the NIK kinase MIG-15 acts in each Rac pathway. Furthermore, we show that the Enabled molecule UNC-34 defines a fourth partially redundant pathway that acts in parallel to Rac/MIG-15 signaling in axon pathfinding. Enabled and the three Racs also act redundantly to mediate AQR and PQR neuronal cell migration. The Racs and UNC-34 Ena might all control the formation of actin-based protrusive structures (lamellipodia and filopodia) that mediate growth cone outgrowth and cell migration. MIG-15 does not act with the three Racs in execution of cell migration. Rather, MIG-15 affects direction of PQR neuronal migration, similar to UNC-40 and DPY-19, which control initial Q cell polarity, and Wnt signaling, which acts later to control Q cell-directed migration. MIG-2 Rac, which acts with CED-10 Rac, RAC-2 Rac, and UNC-34 Ena in axon pathfinding and cell migration, also acts with MIG-15 in PQR directional migration.
Adaptation of Multilocus Sequencing for Studying Variation Within a Major Clone: Evolutionary Relationships of Salmonella enterica Serovar Typhimurium
Authors: Hu Honghua , Lan Ruiting , Reeves Peter R
Published: October 2005

Serovar Typhimurium of Salmonella enterica is a model organism for studies of pathogenesis that exhibits phage-type variation and variation in host range and virulence, but in a recent study showed no sequence variation in four genes, indicating the clonal nature of this serovar. We determined the relationships of 46 Typhimurium isolates of nine phage types using mutational changes detected either by matching AFLP (amplified fragment length polymorphism) fragments to computer-modeled LT2 AFLP fragments or by sequencing intergenic regions. Fifty-one polymorphic sites were detected, which gave a single phylogenetic tree. Comparison with genome sequences of five other serovars, Typhi, Paratyphi A, Gallinarum, Enteritidis, and Pullorum, enabled determination of the root of the tree. Only two parallel events were observed, giving high confidence in the tree branching order. The mutation-based tree provided a high level of consistency and a clear lineage for the Typhimurium isolates studied. This enabled us to show that for seven of the nine phage types used, the isolates studied have a single origin, but that two phage types clearly have more than one independent origin. We found that sequencing intergenic regions provides a good strategy for detection of mutational polymorphisms and study of phylogenetic relationships of closely related isolates and would be applicable to many other species.
Interaction Between Hormonal Signaling Pathways in Drosophila melanogaster as Revealed by Genetic Interaction Between Methoprene-tolerant and Broad-Complex
Authors: Wilson Thomas G , Yerushalmi Yoram , Donnell David M , Restifo Linda L
Published: October 2005

Juvenile hormone (JH) regulates insect development by a poorly understood mechanism. Application of JH agonist insecticides to Drosophila melanogaster during the ecdysone-driven onset of metamorphosis results in lethality and specific morphogenetic defects, some of which resemble those in mutants of the ecdysone-regulated Broad-Complex (BR-C). The Methoprene-tolerant (Met) bHLH–PAS gene mediates JH action, and Met mutations protect against the lethality and defects. To explore relationships among these two genes and JH, double mutants were constructed between Met alleles and alleles of each of the BR-C complementation groups: broad (br), reduced bristles on palpus (rbp), and 2Bc. Defects in viability and oogenesis were consistently more severe in rbp Met or br Met double mutants than would be expected if these genes act independently. Additionally, complementation between BR-C mutant alleles often failed when MET was absent. Patterns of BRC protein accumulation during metamorphosis revealed essentially no difference between wild-type and Met-null individuals. JH agonist treatment did not block accumulation of BRC proteins. We propose that MET and BRC interact to control transcription of one or more downstream effector genes, which can be disrupted either by mutations in Met or BR-C or by application of JH/JH agonist, which alters MET interaction with BRC.
SIZ1/SIZ2 Control of Chromosome Transmission Fidelity Is Mediated by the Sumoylation of Topoisomerase II
Authors: Takahashi Yoshimitsu , Yong-Gonzalez Vladimir , Kikuchi Yoshiko , Strunnikov Alexander
Published: October 2005

The Smt3 (SUMO) protein is conjugated to substrate proteins through a cascade of E1, E2, and E3 enzymes. In budding yeast, the E3 step in sumoylation is largely controlled by Siz1p and Siz2p. Analysis of Siz− cells shows that SUMO E3 is required for minichromosome segregation and thus has a positive role in maintaining the fidelity of mitotic transmission of genetic information. Sumoylation of the carboxy-terminus of Top2p, a known SUMO target, is mediated by Siz1p and Siz2p both in vivo and in vitro. Sumoylation in vitro reveals that Top2p is an extremely potent substrate for Smt3p conjugation and that chromatin-bound Top2p can still be sumoylated, unlike many other SUMO substrates. By combining mutations in the TOP2 sumoylation sites and the SIZ1 and SIZ2 genes we demonstrate that the minichromosome segregation defect and dicentric minichromosome stabilization, both characteristic for Smt3p–E3-deficient cells, are mediated by the lack of Top2p sumoylation in these cells. A role for Smt3p-modification as a signal for Top2p targeting to pericentromeric regions was suggested by an analysis of Top2p–Smt3p fusion. We propose a model for the positive control of the centromeric pool of Top2p, required for high segregation fidelity, by Smt3p modification.