bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-efficacy and music performance
Authors: McPherson Gary E. , McCormick John
Published: June 2006

This study is the second in a series of investigations attempting to clarify relationships between variables that impact on a young musician's ability to perform music (as assessed on a graded music examination). Consistent with studies on school academic subjects, our previous investigation demonstrated the importance of self-efficacy in predicting young musicians’ performance examination results. In the current study, structural equation modelling allowed us to compare two different types of graded music performance examinations. Although differences emerged between the two sets of data, self-efficacy was again found to be the most important predictor of achievement in the examinations. Implications arising from this finding are discussed in the final section of the article.
Performing and teaching: the beliefs and experience of music students as instrumental teachers
Authors: Mills Janet
Published: June 2006

We focus on the music students at a conservatoire (A) that only trains performers and composers (performers/composers); a conservatoire (B) that also trains classroom teachers (education students); and a university (C) with only education students. We used a questionnaire to compare the experience and beliefs as instrumental teachers of the performers/composers at A and B; education students at B and C; and male and female performers/composers. Almost all students expected and hoped to do some work as instrumental teachers on graduation, and most were experienced as instrumental teachers. The beliefs of the two groups of education students were homogeneous. The beliefs of the two groups of performers/composers were similar, but those at B had more limited views. Male performers/composers emerged as less confident than females as instrumental teachers. Training performers/composers alongside classroom teachers does not necessarily enlighten their approach to instrumental teaching; male performers/composers may need particular support with broadening their approach.
Personality characteristics and the attitude to religion of church musicians
Authors: Shuter-Dyson Rosamund
Published: June 2006

The aim of this research was to study the personality characteristics and attitude to religion of church musicians. An opportunity sample of 168 church musicians whose median age was 54, completed a questionnaire on their musical activities, personality and religious beliefs. Personality type as assessed by the Francis Psychological Type Scales differed from the type reported to be characteristic for many musicians, in that the participants showed more preference for thinking over feeling and sensing over intuition. Like many musicians they were introvert rather than extravert and favoured judging over perceiving. With few exceptions, they scored high on the Francis Attitude toward Christianity Scale.
Making Meaning of Local Nonformal Education: Practitioner’s Perspective
Authors: Taylor Edward W.
Published: June 2006

Most often associated with international development programs, local nonformal education, which is practiced in cultural (museums), historical (memorials, battlefields), natural (parks), and commercial (craft, home improvement clinics) settings, has received little substantive attention in the United States. In response, this case study explored two nonformal education sites (state parks and home improvement clinics) to understand how nonformal educators make meaning of their practice. Through observations and interviews, results indicate a much more complex picture of nonformal education than is discussed in the literature, with implications for both formal education and improving the practice of nonformal education.
Studying the Complicated Matter of What Works: Evidence-Based Research and the Problem of Practice
Authors: Dirkx John M.
Published: June 2006

The demand for evidence-based research (EBR) in education has evoked considerable debate regarding the nature of knowledge practitioners hold, how they come to know, and the sociopolitical contexts in which that knowledge is generated. Proponents of EBR such as Michael Feuer stress the need for research that validly identifies solutions to important problems of educational practice. Critics such as Elizabeth St.Pierre decry such approaches to research on practice as epistemologically inappropriate and oblivious to their political and moral implications. Both positions illuminate important dimensions of improving practice, but what works seems to get lost in the rhetoric. In this article, the author suggests that we in adult education take seriously the question of what works in practice by developing a knowledge base grounded in research methods and strategies that give voice to the particularities of practice contexts, what he refers to as the “insider perspective.”
Adult Education and Disability Studies, an Interdisciplinary Relationship: Research Implications for Adult Education
Authors: Clark Mavis A.
Published: June 2006

Disability studies is an emerging field of inquiry that investigates the disability experience as a socially constructed phenomenon similar to issues of race, gender, and class. However, the literature of adult education shows that we are not making these same connections. Nor are we conducting a thorough investigation of how the manifestations of the disability experience affect and/or constrain the adult learning context. This article promotes the idea of an interdisciplinary relationship between adult education and disability studies as a way to investigate the disability experience within the adult learning context. An overview of adult education and disability is provided first, along with a review of the disability studies literature, its history, tenets, and critiques. Embedded within this discussion are suggested implications for adult education practice and theory. The author concludes her discussion with possible ideas for research that she argues will create new lines of inquiry within adult education.
This is just for me(n)
Authors: Amy-Chinn Dee
Published: June 2006

This article argues that the official process by which advertising is regulated in the UK, when applied to the advertising of women's underwear, restricts and undermines, rather than encourages, attempts to renegotiate the discourse that surrounds the representation of women in advertising, particularly when it seeks to construct a discourse that questions the centrality of men to female sexual pleasure. This process judges ads on the basis of whether they are likely to cause ‘serious or widespread offence’. The regulators' interpretation of this ensures that lingerie advertising that represents women as objects for the male gaze remains acceptable, as do ads in which women are deliberately offering up a sexualized self-presentation, while images that seek to negotiate a discourse outside a heterosexuality governed by the coital imperative are considered problematic. This encourages the perpetuation of a conservative framework in which women can be viewed as objects rather than subjects.
Remembering socialism
Authors: Luthar Breda
Published: June 2006

Among the strongest individual memories of life in state socialism was the lack of desired goods, the culture of shortages, and the ‘dictatorship over needs’. This article analyzes the social experience of a culture of shortages, the symbolic value and public meaning of goods, and different practices in the acquisition of material artifacts.As a backdrop to a general discussion of consumption, material culture and desire in socialism, the focus is on the formal properties of the cultural and communicative practices of ‘going shopping to Italy’ in 1950s and 1960s Yugoslavia and draws on personal memories of former shoppers. It explores the system of interaction between border officials and shoppers/smugglers, the traumatic border-crossing experiences of facing customs officers as personalized power, gender divisions, ethnic and class differentiation involved in the shopping expedition, and feelings of foreignness, shame and inadequacy when faced with the ‘West’ in Trieste.
Gene-expression profiling of Waldenström macroglobulinemia reveals a phenotype more similar to chronic lymphocytic leukemia than multiple myeloma
Authors: Chng Wee J. , Schop Roelandt F. , Price-Troska Tammy , Ghobrial Irene , Kay Neil , Jelinek Diane F. , Gertz Morie A. , Dispenzieri Angela , Lacy Martha , Kyle Robert A. , Greipp Philip R. , Tschumper Renee C. , Fonseca Rafael , Bergsagel Peter Leif
Published: June 2006

Waldenström macroglobulinemia (WM) is a B-cell malignancy characterized by the ability of the B-cell clone to differentiate into plasma cells. Although the clinical syndrome and the pathologic characteristics are well defined, little is known about its biology and controversy still exists regarding its cell of origin. In this gene-expression study, we compared the transcription profiles of WM with those of other malignant B cells including (chronic lymphocytic leukemia [CLL] and multiple myeloma [MM]) as well as normal cells (peripheral-blood B cells and bone marrow plasma cells). We found that WM has a homogenous gene expression regardless of 6q deletion status and clusters with CLL and normal B cells on unsupervised clustering with very similar expression profiles. Only a small gene set has expression profiles unique to WM compared to CLL and MM. The most significantly up-regulated gene is IL6 and the most significantly associated pathway for this set of genes is MAPK signaling. Thus, IL6 and its downstream signaling may be of biologic importance in WM. Further elucidation of the role of IL-6 in WM is warranted as this may offer a potential therapeutic avenue.
Enhanced susceptibility to arterial thrombosis in a murine model of hyperhomocysteinemia
Authors: Dayal Sanjana , Wilson Katina M. , Leo Lorie , Arning Erland , Bottiglieri Teodoro , Lentz Steven R.
Published: June 2006

Hyperhomocysteinemia is a risk factor for thrombosis, but the mechanisms are not well defined. We tested the hypothesis that hyperhomocysteinemia accelerates arterial thrombosis in mice. Mice heterozygous for a targeted disruption of the cystathionine β-synthase gene (Cbs+/–) and wild-type littermates (Cbs+/+) were fed either a control diet or a high methionine/low folate (HM/LF) diet for 6 to 8 months to produce graded hyperhomocysteinemia. The time to occlusion of the carotid artery after photochemical injury was shortened by more than 50% in Cbs+/+ or Cbs+/– mice fed the HM/LF diet (P < .001 versus control diet). Carotid artery thrombosis was not accelerated in mice deficient in endothelial nitric oxide synthase (Nos3), which suggests that decreased endothelium-derived nitric oxide is not a sufficient mechanism for enhancement of thrombosis. Cbs+/+ and Cbs+/– mice fed the HM/LF diet had elevated levels of reactive oxygen species in the carotid artery, increased aortic expression of the NADPH oxidase catalytic subunit, Nox4, and decreased activation of anticoagulant protein C in the aorta (P < .05 versus control diet). We conclude that hyperhomocysteinemia enhances susceptibility to arterial thrombosis through a mechanism that is not caused by loss of endothelium-derived nitric oxide but may involve oxidative stress and impairment of the protein C anticoagulant pathway.
Non-side-population hematopoietic stem cells in mouse bone marrow
Authors: Morita Yohei , Ema Hideo , Yamazaki Satoshi , Nakauchi Hiromitsu
Published: June 2006

Most hematopoietic stem cells (HSCs) are assumed to reside in the so-called side population (SP) in adult mouse bone marrow (BM). We report the coexistence of non-SP HSCs that do not significantly differ from SP HSCs in numbers, capacities, and cell-cycle states. When stained with Hoechst 33342 dye, the CD34-/low c-Kit+Sca-1+lineage marker- (CD34-KSL) cell population, highly enriched in mouse HSCs, was almost equally divided into the SP and the main population (MP) that represents non-SP cells. Competitive repopulation assays with single or 30 SP- or MP-CD34-KSL cells found similar degrees of repopulating activity and frequencies of repopulating cells for these populations. Secondary transplantation detected self-renewal capacity in both populations. SP analysis of BM cells from primary recipient mice suggested that the SP and MP phenotypes are interconvertible. Cell-cycle analyses revealed that CD34-KSL cells were in a quiescent state and showed uniform cell-cycle kinetics, regardless of whether they were in the SP or MP. Bcrp-1 expression was similarly detected in SP- and MP-CD34-KSL cells, suggesting that the SP phenotype is regulated not only by Bcrp-1, but also by other factors. The SP phenotype does not specify all HSCs; its identity with stem cell function thus is unlikely.
Marked increased risk of Epstein-Barr virus-related complications with the addition of antithymocyte globulin to a nonmyeloablative conditioning prior to unrelated umbilical cord blood transplantation
Authors: Brunstein Claudio G. , Weisdorf Daniel J. , DeFor Todd , Barker Juliet N. , Tolar Jakub , van Burik Jo-Anne H. , Wagner John E.
Published: June 2006

Umbilical cord blood (UCB) is increasingly used as an alternative source of hematopoietic stem cells for transplantation for patients who lack a suitable sibling donor. Despite concerns about a possible increased risk of Epstein-Barr virus (EBV) posttransplantation lymphoproliferative disorder (PTLD) after UCB transplantation, early reports documented rates of PTLD comparable to those reported after HLA-matched unrelated marrow myeloablative (MA) transplantations. To further investigate the incidence of EBV PTLD after UCB transplantation and potential risk factors, we evaluated the incidence of EBV-related complications in 335 patients undergoing UCB transplantation with an MA or nonmyeloablative (NMA) preparative regimen. The incidence of EBV-related complications was a 4.5% overall, 3.3% for MA transplantations, and 7% for NMA transplantations. However, the incidence of EBV-related complications was significantly higher in a subset of patients treated with an NMA preparative regimen that included antithymocyte globulin (ATG) versus those that did not (21% vs 2%; P < .01). Nine of 11 patients who developed EBV PTLD were treated with rituximab (anti-CD20 antibody), with the 5 responders being alive and disease free at a median of 26 months. Use of ATG in recipients of an NMA preparative regimen warrants close monitoring for evidence of EBV reactivation and potentially preemptive therapy with rituximab.
Anti-Müllerian Hormone Levels in the Spontaneous Menstrual Cycle Do Not Show Substantial Fluctuation
Authors: Hehenkamp Wouter J. K. , Looman Caspar W. N. , Themmen Axel P. N. , de Jong Frank H. , te Velde E. R. , Broekmans Frank J. M.
Published: June 2006

Context: Anti-Müllerian hormone (AMH), a quantitative marker for ovarian reserve, has been suggested to be independent of the classical endocrine fluctuations of the menstrual cycle.

Objective: The objective of the study was to determine whether AMH levels are constant throughout the menstrual cycle, compared with those of FSH, LH, and estradiol.

Design/Patients: Frequent blood sampling was performed in 44 fertile, regularly cycling, female volunteers during one full menstrual cycle.

Setting: The study was conducted at a university hospital.

Main Outcome Measures: AMH, FSH, LH, and estradiol measurements were allocated to one of seven cycle phases, and a multilevel analysis was performed. Consistent fluctuation patterns were tested by fitting sine patterns to the data. Finally, the frequency in which randomly selected individual samples would remain in one of five preset level categories (quintiles) for each of the variables was studied.

Results: A sine pattern fitted to the AMH data was not statistically significant (P = 0.40). In contrast, sine patterns for FSH, LH, and estradiol were highly significant. Comparing the seven cycle phases, no significant differences could be observed between phase-specific AMH levels (P = 0.06). Repeated selection of AMH samples for each individual showed that in 71.5% of selections, AMH values remained in the same quintile, whereas in 27.9% values fell in an adjacent quintile.

Conclusions: AMH levels measured through a full menstrual cycle did not show consistent fluctuation patterns in contrast to levels of FSH, LH, and estradiol. Furthermore, random fluctuations were small, indicating that AMH can be relied on as a cycle-independent marker for ovarian reserve.
The Effect of Androgen Blockade on Granulosa Cell Estradiol Production after Follicle-Stimulating Hormone Stimulation in Women with Polycystic Ovary Syndrome
Authors: Mehta Rinku V. , Malcom Pamela J. , Chang R. Jeffrey
Published: June 2006

Context: Previously, we have shown that women with polycystic ovary syndrome (PCOS) exhibit an exaggerated serum estradiol (E2) response to recombinant human FSH (rhFSH) (150 IU) compared with similarly treated normal women. This enhanced granulosa cell responsiveness is consistent with excessive follicular development after gonadotropin therapy and the corresponding risk of ovarian hyperstimulation syndrome. In vitro studies have shown that granulosa cells treated with androgens display greater FSH-induced E2 production than untreated cells, suggesting a role for androgens in granulosa cell responsiveness.

Main Objective: This study was conducted to determine whether blockade of androgen action in PCOS women by administration of the antiandrogen flutamide would alter E2 responses to rhFSH.

Design: We conducted a prospective cohort study.

Subjects and Setting: We studied 11 women with PCOS at an institutional general clinical research center.

Intervention: On study d 1, each subject received 150 IU rhFSH iv. Frequent blood samples were obtained over 24 h. After completion of rhFSH stimulation, each subject was treated with flutamide, 125 mg, twice daily, for 6 wk. Thereafter, the rhFSH stimulation test was repeated.

Main Outcome Measures: Baseline and stimulated E2 levels before and after treatment were assayed.

Results: Mean baseline and maximally stimulated E2, integrated E2 response, and fold change in E2 were not different before and after treatment. Levels of testosterone, androstenedione, progesterone, 17-hydroxyprogesterone, estrone, and SHBG before and after treatment were unchanged. Baseline dehydroepiandrosterone sulfate levels declined significantly after flutamide therapy.

Conclusion: These findings indicate that in women with PCOS, the E2 hyperresponsiveness to FSH may not be attributable to increased circulating androgens.
A Constitutively Active Mutant of the Human Lutropin Receptor (hLHR-L457R) Escapes Lysosomal Targeting and Degradation
Authors: Galet Colette , Ascoli Mario
Published: June 2006

Using biochemical and imaging approaches, we examined the postendocytotic fate of the complex formed by human choriogonadotropin (hCG) and a constitutively active mutant of the human lutropin receptor (hLHR-L457R) found in a boy with precocious puberty and Leydig cell hyperplasia. After internalization, some of the complex formed by the hLHR-wild type (hLHR-wt) and hCG recycles to the cell surface, and some is found in lysosomes where the hormone is degraded. In contrast, the complex formed by the hLHR-L457R and hCG is not routed to the lysosomes, most of it is recycled to the cell surface and hormone degradation is barely detectable. For both, hLHR-wt and -L457R, there is an hCG-induced loss of cell surface receptors that accompanies internalization but this loss cannot be prevented by leupeptin. The removal of recycling motifs of the hLHR by truncation of the C-terminal tail at residue 682 greatly enhances the lysosomal accumulation of the hormone-receptor complexes formed by the hLHR-wt or the L457R mutant, the degradation of the internalized hormone, and the loss of cell surface receptors. The degradation of the hormone internalized by these mutants as well as the loss of cell surface receptors is largely prevented by leupeptin. These results highlight a previously unrecognized complexity in the postendocytotic trafficking of the hLHR and document a clear difference between the properties of the constitutively active mutant and the agonist-activated hLHR-wt. This lack of lysosomal degradation of the L457R mutant could contribute to its constitutive activity by prolonging the duration of signaling.
A New Way for Efficient Catalysis by Using Low Valent Ruthenium Complexes as Redox Lewis Acid and Base Catalysts
Authors: Murahashi Shun-Ichi , Naota Takeshi
Published: June 2006

Low valent ruthenium hydride complexes are excellent catalysts which act as either redox Lewis acid or base catalysts. Nitriles are substrates which have strong coordination ability towards transition metals, so new types of catalytic transformations of nitriles have been explored using these catalysts. As redox Lewis acid catalysts, hydration of nitriles, amidation of amines, and esterification of alcohols with nitriles can be achieved. The same catalyst can be used for direct formation of carbon nucleophiles by C–H activation of pronucleophiles, such as nitriles and carbonyl compounds, hence catalytic aldol-type reactions and Michael-type additions can be performed under neutral and mild conditions.
Deuterium-Induced Isotope Effects of a C–H···Se “Hydrogen Bond” on the IR and NMR Spectra of 6H,12H-Dibenzo[b,f][1,5]diselenocin
Authors: Iwaoka Michio , Komatsu Hiroto , Tomoda Shuji
Published: June 2006

Deuterium-induced isotope effects of the C–H···Se nonbonded interaction of 6H,12H-dibenzo[b,f][1,5]diselenocin (1) were investigated. The IR spectroscopic behavior of 6H,12H-dibenzo[b,f][1,5]diselenocin-6,6,12,12-d4 (1-d4) was compared with that of the reference compound (benzyl-α,α-d2 phenyl selenide (2-d2)). The results for both boat (1B) and chair (1C) conformers of 1 indicated that the C–H···Se interaction causes the decrease in the low wavenumber shift of ν1 (Δν1 = −2 cm−1 for 1B-d4 and −12 cm−1 for 1C-d4, whereas Δν1 = −15 cm−1 for 1B and −52 cm−1 for 1C). The 77Se NMR showed the upfield isotope shift due to the through-space C–H···Se interaction (ΔΔδ = 0.44 ppm for 1B and 0.25 ppm for 1C). These findings clearly suggested that the interaction is attractive in nature. MO calculations at the HF/3-21G* level and NBO analysis showed the importance of the electron delocalization from the selenium lone pair to the antibonding orbital of the C–H bond. These observations strongly suggested that the interaction be called a C–H···Se hydrogen bond.
Rotational Behavior of N-(2-Naphthylmethyl)carbazole in a 1,2-Dichloroethane/Poly(ethylene oxide) Mixture Measured by a Time-Resolved Fluorescence Depolarization Method
Authors: Tsunomori Fumiaki , Ushiki Hideharu
Published: June 2006

Stationary and nanosecond time-resolved fluorescence depolarization spectroscopy has been used to detect the rotational behavior of N-(2-naphthylmethyl)carbazole as a function of the solvent viscosity. The variation in the viscosity was effected by the addition of poly(ethylene oxide), and the range of the variation was 0.78 N m−2 s−1 to 33 × 10−3 N m−2 s−1. The viscosity dependence of the rotational diffusion coefficient (Dr) in the high-viscosity region was different from that in the low viscosity region. Radii of gyration of N-(2-naphtylmethyl)carbazole in the low and high viscosity regions were about 8 and 4 Å, respectively. The former agrees with the total size of N-(2-naphthylmethyl)carbazole, and the latter with the size of the cabazolyl group. The crossover point of the rotational motion of N-(2-naphthylmethyl)carbazole was at a concentration of 0.6 g ml−1 of poly(ethylene oxide), which coincided with the overlap concentration of poly(ethylene oxide) molecules. Therefore, the rotational mode of N-(2-naphthylmethyl)carbazole varies from the whole to the carbazolyl group by the addition of poly(ethylene oxide).
Dielectric Study Concerning the Dynamics of Water in Artificial Stratum Corneum Lipids
Authors: Mizushima Hiromoto , Naito Satoru
Published: June 2006

The dielectric properties were studied on an artificial stratum corneum lipids–water system, consisting of a pseudo-ceramide, stearic acid, cholesterol, and water, by using time-domain reflectometry. Two relaxation processes were found in the lipid mixtures of pseudo-ceramide/stearic acid (1/1 mole ratio)/cholesterol–water (10 wt%), over a frequency range of 107—1010 Hz. The high-frequency relaxation peaks, located at around 7—16 GHz, were attributed to free water relaxation. The low-frequency processes were observed around 500—900 MHz, and were concluded to be due to bound water relaxation in the lipid matrix, judging from the relaxation time. Upon increasing the cholesterol concentration, a progressive increase of the relaxation strength of free water appeared, whereas that of bound water decreased. In this system, the incorporation of cholesterol was found to decrease the entropy changes by melting, which reflected the disorder of the arrangement of the lipid molecules. Therefore, changes in the dielectric properties, due to an increase in cholesterol, would be associated with the structural changes of lipids.
Theoretical Study of the Ionized Electronic Structure of the Octahedral Complex MoF6
Authors: Morita Hiroshi , Nakai Hiromi , Tomasello Pasquale , Nakatsuji Hiroshi
Published: June 2006

The SAC (symmetry adapted cluster) and SAC-CI (SAC-configuration interaction) theories were used to calculate the ground and ionized states of MoF6. Compared with the results of previous theoretical studies, the present SAC-CI results are in good agreement with experimental data. We clearly show the effects of the electron correlation and ligand-polarization functions. In this molecule, the ligand polarization even affects the HF orbitals. These polarization functions make the electron density of the ligands expand toward the central metal, which leads not only to a stabilization of the total energy, but also to a destabilization of the valence orbital energies. These changes can be explained by changes in the one- and two-electron integrals. On the other hand, the correlation effect makes the electron density of the ligands expand outwards. This is an inverse effect of the polarization functions.
The Electronic Spectra of Ethylene
Authors: Ballard Charles C , Hada Masahiko , Nakatsuji Hiroshi
Published: June 2006

The SAC (Symmetry Adapted Cluster) and SAC-CI methods have been applied to the calculation of the valence and Rydberg electronic states of ethylene using large basis sets. Three singlet valence states are computed to lie below 10 eV: the V(1B1u) state and the σπ* 21B1g and 21B1g states. The excitation energies obtained for the low-lying Rydberg states are in excellent agreement with experiment, for the most part within 0.1 eV. The assignment of the 3R band to two Rydberg transitions is confirmed.
Extraction of Magnesia from Egyptian Serpentine Ore via Reaction with Different Acids. I. Reaction with Sulfuric Acid
Authors: Fouda Mohamed Fikry Ragai , Amin Rawhya El-Sayed , Abd-Elzaher Mokhles Mohamed
Published: June 2006

The present study is concerned with the effectiveness of use of local Egyptian serpentine ore for production of magnesium sulfate. An investigation of the ore composition was carried out by means of X-ray diffractometry and chemical analysis. The reaction of sulfuric acid with the ore was studied at different leach parameters under laboratory conditions for the uncalcined and calcined ore. The dissolution rate constants of magnesia were determined by the analysis of the experimental data. The resultant activation energy of reaction between the acid and the studied ore was lower than the values reported previously. This result is discussed in terms of structural changes of serpentine during the calcination of ore which may affect its reactivity towards acids. The high yield of magnesia extraction from the ore emphasizes the possibility of exploitation of the ore in the preparation of sulfate salt with a lower price.
Extraction of Magnesia from Egyptian Serpentine Ore via Reaction with Different Acids. II. Reaction with Nitric and Acetic Acids
Authors: Fouda Mohamed Fikry Ragai , Amin Rawhya El-Sayed , Abd-Elzaher Mokhles Mohamed
Published: June 2006

The results of a kinetic study of the dissolution of magnesia from Egyptian serpentine ore with nitric and acetic acids are presented. The effects on the magnesia dissolution of (a) temperature ranging from 30 to 105 °C, (b) time ranging from 2.5 min to several days, and (c) molal ratios between one of the acids and MgO in the ore ranging from 4.42 to 3.86, are presented. From the analysis of the dissolution rate on the basis of a core model, it was found that dissolution rate of MgO could be well expressed by a rate equation based on the rate-limiting step of the surface chemical reaction. The apparent activation energies were ca. 17.4 and 8.3 kcal mol−1 for nitric and acetic acid respectively.

The high activation energy of reaction with nitric acid was found to be associated with relatively higher values of activation entropy (ΔS* = −19.5 cal mol−1 K−1), whereas the relatively low activation energy of reaction with acetic acid is associated with negative values of entropy of activation (ΔS* = −44.3 cal mol−1 K−1). The values of the latter parameter indicated that their values are related to the complexing affinity of magnesium cation towards acid anion. Thus, the values of entropy of activation are the predominant factor for the reaction between the ore and studied acids.
Mathematical Model for Adsorption of Boric Acid on a Boron-Specific Ion Exchanger
Authors: Sahin Sami
Published: June 2006

The present study was undertaken to investigate boron removal from the waste waters of borax and boric acid producing plants. A boron-specific resin, Amberlite XE 243, was selected for the present work. Experimental results show that the ion-exchange operations are effective in removing boron from the waste waters.

The variation of boron concentrations in the effluents has been observed to depend, for various initial boron concentrations, C0, on the ratio of the filtrate volume to the volume occupied by resin.

An empirical equation has been developed relating boron concentration, C, to filtrate and resin volumes V1 and V, respectively, as

C = 2.34 × 10−6·C0(V)−0.043(V1)2.80
Magneto-Structural Correlations in Alkoxo-Bridged Copper(II) Compounds
Authors: Emori Shuji , Goto Hirofumi , Mitsumasu Hiroshi
Published: June 2006

The magnetic susceptibilities of the compounds [Cu(bbip)(RO)]X (bbip = 1,3-bis(benzimidazol-2-yl)propane; R = CH3, C2H5; X = NO3, ClO4) and related alkoxo-bridged copper(II) compounds were determined over the temperature range 80—300 K. For the dinuclear entities [Cu(OR)2Cu′]2+, the strength of the exchange couplings is discussed in terms of the in-plane and out-of-plane tilts of the C–O vector from the bisector of the Cu–O–Cu′ angle.
Syntheses and Crystal Structures of Bis(dimethyldithiocarbamato)(4,6-diphenyl-4,6-diphosphanonane-1,9-diammonium)cobalt(III) and Chloro(4,9-diphenyl-4,9-diphosphadodecane-1,12-diamine)nickel(II) Complexes
Authors: Kashiwabara Kazuo , Watanabe Masayuki , Kita Masakazu , Suzuki Takayoshi
Published: June 2006

The reaction of tetramethylthiuram disulfide with a methanol solution containing CoCl2·6H2O and 4,6-diphenyl-4,6-diphosphanonane-1,9-diamine (313NPPN) gave complexes of [Co(dtc)2{rac(P)- or meso(P)-313HNPPNH}]3+ (313HNPPNH = diprotonated form of 313NPPN, dtc = dimethyldithiocarbamate ion). The crystal structure of the perchlorate salt of the meso(P) isomer was determined by X-ray analysis. Crystal data: monoclinic, P21/c, a = 10.789(2), b = 30.325(9), c = 12.888(2) Å, β = 102.06(1)°, V = 4123(1) Å3, Dx = 1.55 g cm−3, Z = 4, and R = 0.077 for 3347 reflections. The 313HNPPNH ligand in the complex coordinates to the Co(III) center through two phosphorus atoms as a didentate four-membered chelate ligand. The crystal structure of [Co(dtc)2{NH2(CH2)3P(CH2OH)(C6H5)}]B(C6H5)4, which formed as a by-product in the preparation of the above Co(III)–313HNPPNH complexes, was also determined. Crystal data: triclinic, , a = 13.817(2), b = 15.277(3), c = 10.737(2) Å, α = 109.90(1), β = 94.14(2), γ = 101.00(1)°, V = 2068.8(7) Å3, Dx = 1.31 g cm−3, Z = 2, and R = 0.053 for 4303 reflections. [NiCl{rac(P)-343NPPN}]PF6 (343NPPN = 4,9-diphenyl–4,9-diphosphadodecane-1,12-diamine) was prepared by the reaction of 343NPPN with NiCl2·6H2O, and the crystal structure was determined. Crystal data: monoclinic, P21/n, a = 8.367(2), b = 24.058(2), c = 13.988(2) Å, β = 106.17(1)°, V = 2704(1) Å3, Dx = 1.54 g cm−3, Z = 4, and R = 0.053 for 3043 reflections. The geometry of the complex is a distorted square pyramid with a chloride ion at the apical position, and the 343NPPN ligand functions as a tetradentate chelate ligand.
31P and 27Al NMR Studies on the Coordination of Aluminum(III) with Tetraphosphate
Authors: Miyazaki Yoshinobu , Kura Genichiro , Tsuzuki Hirohisa , Sakashita Hirofumi
Published: June 2006

The binding isomerization of Al(III) with linear tetraphosphate has been investigated in the pH range of 1 to 9 using 31P and 27Al NMR spectroscopy. The complexes of 1 : 1 (=Al(III) : P4O13) stoichiometry with monodentate and didentate bindings, and the complex of 2 : 1 stoichiometry with two didentate bindings coexist in equilibrium. The concentration ratio of the 1 : 1 complexes with didentate to monodentate binding is 2.02 ± 0.19 at pH 3. The relative concentration of the monodentate complex increases along with decreasing the pH. The possible binding positions of Al(III) to tetraphosphate in these complexes are discussed.
Crystal Structures and Acetonitrile Exchange of Palladium(II) Complexes with Bis(3-aminopropyl)amine and Diethylenetriamine. Effects of Ion-Pair Formation
Authors: Yagyu Takeyoshi , Aizawa Sen-ichi , Hatano Keiichiro , Funahashi Shigenobu
Published: June 2006

The crystal structures of palladium(II) complexes with tridentate amine and acetonitrile, [Pd(CH3CN)(dptn)](CF3SO3)2 (1) and [Pd(CH3CN)(dien)](CF3SO3)2 (2) (dptn = bis(3-aminopropyl)amine and dien = diethylenetriamine), have been determined by X-ray crystal structure analysis. The central palladium(II) ion has a distorted square-planar geometry. The five-membered chelate rings of the dien ligand in 2 are more strained than the six-membered chelate rings of the dptn ligand in 1, as indicated from the difference in the angles of terminal N–Pd–terminal N and the averaged Pd–N–C angles around the terminal nitrogens. The kinetics of acetonitrile exchange of 1, 2, and [Pd(CH3CN)(dien)](BF4)2 (3) have been investigated by the 1H NMR line-broadening technique. The observed rate constants can be expressed by kobs = k1 + k2 [CH3CN] from the dependence of kobs on the acetonitrile concentration. It has been indicated that the k1 and k2 paths proceed via the dissociative and associative modes of activation, respectively. The dissociative k1 path is promoted by the ion-pair formation where the bound ligand effect is enhanced by the electrostatic interaction between the counter anions and amine protons. The reaction mechanisms are discussed in terms of the steric and electronic factors of the bound ligands (dptn and dien) and the effect of the ion-pair formation with the counter anions (CF3SO3− and BF4−).
Effect of 2,2′-Bipyridine and 1,10-Phenanthroline on the Redox Reaction of Metal Ions and Its Application to Potentiometric Titrations of Vanadium(IV) and Cobalt(II)
Authors: Teshima Norio , Kawashima Takuji
Published: June 2006

The effect of 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) on the redox reactions of vanadium(IV) with iron(III), cobalt(II) with vanadium(V), and cobalt(II) with chromium(VI) was studied potentiometrically. In the presence of bpy or phen, the formal potential of the Fe(III)/Fe(II) system is higher than that of the V(V)/V(IV) system in the pH range 3—6. A large potential break was thus observed at the equivalence point when the titration of 1 × 10−3mol dm−3 vanadium(IV) with iron(III) was carried out in the presence of 2 × 10−2 mol dm−3 bpy or phen at pH 5, while the potentiometric determination of vanadium(IV) with iron(III) was impossible in the absence of these ligands. On the other hand, the oxidation reactions of cobalt(II) to cobalt(III) by vanadium(V) or chromium(VI) took place easily in the presence of bpy or phen at a pH around 1. Using these reactions, we propose a titrimetric procedure for the determination of 1 × 10−3 mol dm−3 cobalt(II). A visual end point detection with Variamine Blue B (N-(4-methoxyphenyl)-1,4-phenylenediamine) as a redox indicator was presented for the titration of 1 × 10−3 mol dm−3 cobalt(II) with chromium(VI) in the presence of 2.5 × 10−2 mol dm−3 phen.
Gas-Phase Substituent Effects in Stabilized Benzylic Carbocations. Basicities of Benzaldehydes, Acetophenones, and Methyl Benzoates in the Gas Phase
Authors: Mishima Masaaki , Mustanir  , Fujio Mizue , Tsuno Yuho
Published: June 2006

The gas-phase basicities of a series of aromatic carbonyl compounds (ArCOR; R = OMe, Me, H) were measured based on the proton-transfer equilibrium method using a pulsed ICR mass spectrometer. The effects of ring-substituents on the gas-phase basicities were analyzed in terms of the Yukawa–Tsuno equation. It was shown that the resonance demand parameter (r+) decreases significantly from 1.06 for the benzaldehyde to 0.50 for the methyl benzoate in increasing order of the electron-donating ability of the R group directly linked to the carbonyl carbon. This indicates that the π-charge formed in the conjugate acid ion is competitively delocalized into an aryl group and an R group. In contrast, the ρ value is nearly constant at −11 (in kcal mol−1 per σ unit) in all series. Most importantly, it was found that the r+ value in the gas phase is in agreement with that for the basicities in aqueous solution, whereas the ρ value is significantly reduced in aqueous solution. This fact led us to the conclusion that the solvation of a cation reduces the central charge so as to lower the response to substituent perturbation, essentially without changing the nature of the intramolecular charge-delocalization.
Simple and Rapid Determination of the Activation Parameters of Organic Reactions by Temperature-Dependent NMR Spectroscopy I. Application to Irreversible Reactions
Authors: Satoh Masahiro , Hirota Minoru
Published: June 2006

A rapid and convenient method for the evaluation of activation enthalpies and entropies of reactions in solutions was contrived. This was realized by the stepwise elevation of the temperature of a reaction system using a variable temperature apparatus of NMR spectrometer. A repetition of rapid collection of FIDs (Free Inductive Decays) at every plateau part of temperature at regular intervals allows us to determine the time-conversion curve, from which the rates at various temperatures were obtained as the first derivatives. Several examples of applications are shown.
Chiral Bimetallic Boronic Esters: A Donor–Acceptor Coexisting Receptor for Amines
Authors: Nozaki Kyoko , Yoshida Masanori , Takaya Hidemasa
Published: June 2006

A chiral bimetallic Lewis acid, 2,2′-(1,2-phenylene)bis[(4R,5R)-4,5-diphenyl-1,3,2-ioxaborolane] (1a), has been synthesized. The exceptionally strong binding of 1a with benzylamine was demonstrated by titrations. The complex formation ratio of 1a : amine = 1 : 2 was determined by a Job plot. The binding constants, K1 and K2, were determined by non-linear curve fitting to be K1 << K2. The results can be explained in terms of an allosteric effect. The first amine molecule coordinates with one of the two boron atoms of 1a; at the same time, one NH proton interacts with one of the two oxygen atoms in the other dioxaborolane ring to form a hydrogen bond. As a result, the two dioxaborolane rings are conformationally fixed by two-point binding to provide a preferable binding site for the second amine molecule. Although only a small chiral recognition of 1-phenylethylamine has been obtained with 1a, the clear separation of the peaks of the amine provides the possibility to use 1a as an NMR chiral-shift reagent.
Synthesis of (±)-Stemonamide by the Application of Oxidative Coupling Reactions of Stannyl Compounds with Silyl Enol Ethers
Authors: Kohno Yasushi , Narasaka Koichi
Published: June 2006

A tricyclic Stemona alkaloid, (±)-stemonamide, can be synthesized by applying the oxidative coupling reactions of stannyl compounds with silyl enol ethers to construct the carbon skeleton.
Synthesis of 2-Geranyl- and 2-Farnesyl-Substituted Geranylgeraniols and Their Phosphates
Authors: Nagano Hajime , Kudo Kaori
Published: June 2006

Allylation of the lithiated cyclohexylimine of (2E,6E,10E)-geranylgeranial with (2E)-geranyl bromide followed by acid-catalyzed hydrolysis gave (2E)-α-, (2Z)-α-, and γ-geranyl-substituted geranylgeranials. Farnesyl-substituted geranylgeranials were also prepared. (2Z)-α-Geranyl- and (2Z)-α-farnesyl-substituted geranylgeranials were photoisomerized to the corresponding (2E)-isomers, respectively. The branched polyprenyl alcohols, obtained by the reduction of these aldehydes, were transformed to geranyl- and farnesyl-substituted geranylgeranyl phosphates.
Cycloaddition of Bis[3,3-bis(diethylamino)thioacryloyl] Disulfide with Alkynic Dienophiles: A New Access to 2H-Thiopyran-2-thiones
Authors: Akimoto Keiichi , Masaki Kazuto , Nakayama Juzo
Published: June 2006

The reaction of bis[3,3-bis(diethylamino)thioacryloyl] disulfide (1) with dimethyl acetylenedicarboxylate gave dimethyl 4-diethylamino-2-thioxo-2H-thiopyran-5,6-dicarboxylate in 69% yield. Similarly, a series of alkynic dienophiles reacted with 1 to give the corresponding 2H-thiopyran-2-thione derivatives in modest-to-reasonable yields. A full experimental description of this 2H-thiopyran-2-thione formation is given and a mechanism involving [4+2]cycloaddition followed by homolytic cleavage of the S–S bond is presented.
Physical and Catalytic Properties of MgO Prepared Using Citric Acid
Authors: Nakayama Tomohiro , Sato Satoshi , Nozaki Fumio
Published: June 2006

The physical properties, particularly the pore structure and specific surface area, of MgO prepared using citric acid was investigated. Both the specific surface area and the pore volume increased steeply with the weight loss at around 600 K at which citric acid was decomposed. The pore size distribution of the sample was controlled by the ratio of citric acid and the temperature of heat treatment. In a catalytic decomposition of 4-hydroxy-4-methyl-2-pentanone into acetone, the reaction rate was proportional to the specific surface area of the sample, and the catalysts prepared by this technique had high reaction rates because of their high specific surface areas.
Synthesis of Vinyl Polymers Incorporating Different Crowned Azobenzene Moieties and Their Application to Photoresponsive Ion-Conducting System
Authors: Tokuhisa Hideo , Yokoyama Masaaki , Kimura Keiichi
Published: June 2006

Vinyl polymers carrying a crowned azobenzene side chain, which have a crown ether moiety and an azobenzene moiety in two different ways, were synthesized and their ion-conducting behavior investigated. The crowned azobenzene vinyl polymer carrying a crown ether moiety apart from its azobenzene moiety, 1, exhibited distinct liquid crystal phases, which were stabilized by the addition of alkali metal perchlorates. Ion-conducting composite films containing crowned azobenzene vinyl polymer 1 underwent remarkable photoinduced ionic-conductivity switching. The system of vinyl polymer 2, which carries a crown-ether ring in the vicinity of its azobenzene moiety, is greater in the magnitude of photoinduced ionic-conductivity change (ionic-conductivity ratio) than the system of vinyl polymer 1. X-Ray diffraction measurements suggested that the difference in the ionic-conductivity switching between the two crowned azobenzene polymers is derived from the difference in the order–disorder arrangement of the crown ether moiety on the photoisomerization of the azobenzene moiety from its trans form to the corresponding cis one.
Endohedral Metallofullerenes: New Spherical Cage Molecules with Interesting Properties
Authors: Nagase Shigeru , Kobayashi Kaoru , Akasaka Takeshi
Published: June 2006

Endohedral metallofullerenes (fullerenes containing metals inside the carbon cage) have long attracted special interest as new spherical molecules with novel properties. Recent important progress has been marked by successful isolation and purification in macroscopic quantities. With the availability of such purified samples, it has been possible to investigate the structures, electronic properties, and chemical reactivities. Very recent progress in the theoretical and experimental studies of endohedral metallofullerenes is summarized to show what are known or still unknown for the future material, catalytic, and biological applications.
The Study of the Electron–Positron Pair in CS2
Authors: Hirade Tetsuya
Published: June 2006

Ole E. Mogensen reported that CS2 was the only liquid which showed large decrease of the Ps intensity with lowering the temperature, even though electron and positron could encounter with each other at low temperatures such as −100 °C. The intensity change by the positron annihilation lifetime was observed at a little lower temperature by the positron annihilation angular correlation. Here I measured the change of intensity and lifetime of the longest lifetime component caused by varying the surface tension, the dielectric constant, and the temperature, to clarify the positron state in CS2. These experimental results confirm the ideas of the “fourth positron state” and the “squeezed positronium state” which were proposed by Ole E. Mogensen.
Electrochemical Reduction of N2O on Gas-Diffusion Electrodes
Authors: Konishi Nozomi , Hara Kohjiro , Kudo Akihiko , Sakata Tadayoshi
Published: June 2006

The electrochemical reduction of N2O to N2 on gas-diffusion electrodes (GDEs) modified by Pt and Ni electrocatalysts at room temperature was studied. The Faradaic efficiency for the reduction of N2O was 100%, even for a low concentration of N2O gas at a low current density. When 0.6 mmol of N2O was electrolyzed, 99.7% of the N2O was decomposed at a constant current density of 6.4 mA cm−2. The Faradaic efficiency of N2O reduction was increased by using pulse electrolysis.
Inclusion Complexation of 4-Biphenylcarboxylate, 4-Biphenylacetate, and 4-Biphenylsulfonate with α-Cyclodextrin, Studied by Pulse Radiolysis
Authors: Yamamoto Yukio , Yoshida Yoichi , Tagawa Seiichi
Published: June 2006

Inclusion complexation of 4-biphenylcarboxylate (BPC−), 4-biphenylacetate (BPA−), and 4-biphenylsulfonate (BPS−) with α-cyclodextrin (α-CD) has been investigated by a pulse radiolysis method. The one-electron reduction of BPC− and BPS− by the hydrated electron was effectively retarded by the 1 : 2 complexation with α-CD as well as by the 1 : 1 complexation with β-CD investigated in our previous study. The retarding effect of α-CD was observed at much higher host concentrations than that of β-CD. No apparent effect of α-CD was observed on the one-electron reduction of BPA−, but the effect of β-CD was similar to those for BPC− and BPS−. The result indicates that the methylene group of BPA− sterically inhibits the formation of the 1 : 2 complex. The rate constant for the one-electron reduction of the 1 : 2 complex of BPC− with α-CD was 1.0 × 109 dm3 mol−1 s−1, which is smaller than that of the 1 : 1 complex with β-CD, 2.5 × 109 dm3 mol−1 s−1. It is demonstrated that the biphenylyl group of the 1 : 2 complex with α-CD is screened from the attack of the hydrated electron more effectively than that of the 1 : 1 complex with β-CD.