bluuebunny/crossref_metadata_2025 huggingface dataset:
Microscale sample deposition onto hydrophobic target plates for trace level detection of neuropeptides in brain tissue by MALDI‐MS
Authors: Wei Hui , Dean Stacey L. , Parkin Mark C. , Nolkrantz Kerstin , O'Callaghan James P. , Kennedy Robert T.
Published: October 2005

A sample preparation method that combines a modified target plate with a nanoscale reversed‐phase column (nanocolumn) was developed for detection of neuropeptides by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). A gold‐coated MALDI plate was modified with an octadecanethiol (ODT) self‐assembled monolayer to create a hydrophobic surface that could concentrate peptide samples into a ∼200–500‐µm diameter spot. The spot sizes generated were comparable to those obtained for a substrate patterned with 200‐µm hydrophilic spots on a hydrophobic substrate. The sample spots on the ODT‐coated plate were 100‐fold smaller than those formed on an unmodified gold plate with a 1‐µl sample and generated 10 to 50 times higher mass sensitivity for peptide standards by MALDI‐TOF MS. When the sample was deposited on an ODT‐modified plate from a nanocolumn, the detection limit for peptides was as low as 20 pM for 5‐µl samples corresponding to 80 amol deposited. This technique was used to analyze extracts of microwave‐fixed tissue from rat brain striatum. Ninety‐eight putative peptides were detected including several that had masses matching neuropeptides expected in this brain region such as substance P, rimorphin, and neurotensin. Twenty‐three peptides had masses that matched peaks detected by capillary liquid chromatography with electrospray ionization MS.1, 2 Copyright © 2005 John Wiley & Sons, Ltd.
Electrospray ionization mass spectrometry study on dipeptide 4‐chlorobutyl ester produced from refluxing of amino acid with phosphoryl chloride in tetrahydrofuran
Authors: Zhou Gui Ji , Liu Ze , Wang Tong Jian , Xu Peng Xiang , Tang Gou , Ye Yong , Zhao Yu Fen
Published: October 2005

Phosphoryl chloride was able to promote the formation of peptide and the ringopening of tetrahydrofuran (THF) followed by a sequence of successive reactions by simply refluxing. ESI multistage tandem mass spectrometry was applied to trace the reaction and elucidate the product structures, dipeptide 4‐chlorobutyl ester. Copyright © 2005 John Wiley & Sons, Ltd.
Fruit thinning and shade improve bean characteristics and beverage quality of coffee (Coffea arabica L.) under optimal conditions
Authors: Vaast Philippe , Bertrand Benoit , Perriot Jean‐Jacques , Guyot Bernard , Génard Michel
Published: October 2005

Under two contrasting light regimes (full sun and 45% shade) and the optimal coffee‐growing conditions of the central valley of Costa Rica, production pattern, bean characteristics and beverage quality were assessed over two production cycles on dwarf coffee (Coffea arabica L. cv. Costa Rica 95) trees with varying fruit loads (quarter, half and full loads) imposed by manual fruit thinning. Shade decreased coffee tree productivity by 18% but reduced alternate bearing. Shade positively affected bean size and composition as well as beverage quality by delaying berry flesh ripening by up to 1 month. Higher sucrose, chlorogenic acid and trigonelline contents in sun‐grown beans pointed towards incomplete bean maturation and explained the higher bitterness and astringency of the coffee beverage. Higher fruit loads reduced bean size owing to carbohydrate competition among berries during bean filling. These results have important implications in terms of agricultural management (shade, fruit thinning, tree pruning) to help farmers increase coffee plantation sustainability, produce coffee beans of larger size and higher quality and ultimately improve their revenues, especially during times of world overproduction. Copyright © 2005 Society of Chemical Industry
Performance of hollow‐fiber flow field‐flow fractionation in protein separation
Authors: Park Ilyong , Paeng Ki‐Jung , Kang Dukjin , Moon Myeong Hee
Published: October 2005

Since hollow‐fiber flow field‐flow fractionation (HF FlFFF) utilizes a cylindrical channel made of a hollow‐fiber membrane, which is inexpensive and simple in channel assembly and thus disposable, interests are increasing as a potential separation device in cells, proteins, and macromolecules. In this study, performance of HF FlFFF of proteins is described by examining the influence of flow rate conditions and length of fiber (polyacrylonitrile or PAN in this work) on sample recovery as well as experimental plate heights. The interfiber reproducibility in terms of separation time and recovery was also studied. Experiments showed that sample recovery was consistent regardless of the length of fiber when the effective field strength (equivalent to the mean flow velocity at the fiber wall) and the channel void time were adjusted to be equivalent for channels of various fiber lengths. This supported that the majority of sample loss in HF FlFFF separation of apoferritin and their aggregates may occur before the migration process. It is finally demonstrated that HF FlFFF can be applied for characterizing the reduction in Stokes' size of low density lipoproteins from blood plasma samples obtained from patients having coronary artery disease and from healthy donors.
Simultaneous determination of seven triterpenoids and triterpenoid saponins in Folium Ilicis Purpureae by high performance liquid chromatography coupled with evaporative light scattering detection
Authors: Liao Li‐Ping , Li Song‐Lin , Li Ping
Published: October 2005

A new HPLC coupled with evaporative light scattering detection method was established for the simultaneous determination of seven triterpenoids and triterpenoid saponins in Folium Ilicis Purpureae traditional Chinese medicinal herb derived from the leaf of Ilex purpurea, namely, 3‐O‐β‐D‐glucopyranosyl (1 → 2)‐β‐D‐[6‐O‐methyl‐glucuronopyranosyl]‐28‐O‐β‐D‐glucopyranosyl oleanolic acid (SQ‐1), pedunculoside (SQ‐2), 23‐hydroxytormentic acid 28‐O‐β‐D‐glucopyranoside (SQ‐3), 23‐hydroxytormentic acid (SQ‐4), rutundic acid (SQ‐5), ilexoside B (SQ‐6), and ursolic acid (SQ‐7). The optimal chromatographic conditions were achieved on a C18 column with a linear gradient elution of mobile phase A: deionized water–isopropyl alcohol–THF–acetic acid (90 : 10 : 6 : 1, v/v) and B: methanol–isopropyl alcohol–THF–acetic acid (90 : 10 : 6 : 1, v/v) at the flow rate of 1.0 mL/min; temperature for drift tube was set at 98°C and nitrogen flow rate was 2.8 L/min. All calibration curves of the seven compounds showed good linear regression (r 2 > 0.995) within test ranges. The developed method has good repeatability for quantitation of all analytes interested with overall intraday and interday variation of less than 4.1%. The LOD (S/N = 3) and LOQ (S/N = 10) were less than 0.13 and 0.26 μg/mL, respectively, for all analytes. The established method was successfully used to evaluate the quality of Folium Ilicis Purpureae samples of different collections.
Separation and determination of seven fluoroquinolones by pressurized capillary electrochromatography
Authors: Lü Haixia , Wu Xiaoping , Xie Zenghong , Lin Xucong , Guo Liangqia , Yan Chao , Chen Guonan
Published: October 2005

In this paper, pressurized CEC was used for the separation and determination of seven fluoroquinolones (FQs). The effect of different experimental conditions, such as the concentration and pH of the buffer, the organic modifier concentration, the surfactant and ion‐paring agents added to the electrolyte, and applied voltage were studied. All the seven FQs were baseline separated using mobile phase containing 27% v/v ACN, 5 mmol/L Na2HPO4 buffer (pH 4.0 adjusted using citric acid), 11 mmol/L SDS, and 0.01% TEA v/v at detection wavelength of 287 nm and at an applied voltage of –10 kV. The calibration curves were linear (r >0.9991) over a concentration range of 1.0–50.0 mg/L for norfloxacin (NFLX); 2.5–50.0 mg/L for fleroxacin (FLX), ciprofloxacin (CPFX), and lomefloxacin (LMX); and 5.0–50.0 mg/L for enoxacin (ENX), ofloxacin (OFLX), and gatifloxacin (GFLX). The detection limits (S/N = 3) for ENX, OFLX, FLX, NFLX, CPFX, LMX, and GFLX were 0.5, 0.8, 0.4, 0.2, 0.4, 0.5, and 1.0 mg/L, respectively. The method is simple, rapid, and reproducible. It was successfully applied to the analysis of fish muscle samples spiked with FQs. Mean recoveries ranged from 81.6 to 97.6%.
A boundary condition with memory for the Kirchhoff plate equations with non‐linear dissipation
Authors: Park Jong‐Yeoul , Kang Jum‐Ran
Published: October 2005

This paper is concerned with the existence of solutions for the Kirchhoff plate equation with a memory condition at the boundary. We show the exponential decay to the solution, provided the relaxation function also decays exponentially. Copyright © 2005 John Wiley & Sons, Ltd.
Tyrphostin‐A47 inhibitable tyrosine phosphorylation of flagellar proteins is associated with distinct alteration of motility pattern in hamster spermatozoa
Authors: Mariappa Daniel , Siva Archana B. , Shivaji Sisinthy , Seshagiri Polani B.
Published: October 2005

To acquire fertilizing potential, mammalian spermatozoa must undergo capacitation and acrosome reaction. Our earlier work showed that pentoxifylline (0.45 mM), a sperm motility stimulant, induced an early onset of hamster sperm capacitation associated with tyrosine phosphorylation of 45–80 kDa proteins, localized to the mid‐piece of the sperm tail. To assess the role of protein tyrosine phosphorylation in sperm capacitation, we used tyrphostin‐A47 (TP‐47), a specific protein tyrosine kinase inhibitor. The dose‐dependent (0.1–0.5 mM) inhibition of tyrosine phosphorylation by TP‐47 was associated with inhibition of hyperactivated motility and 0.5 mM TP‐47‐treated spermatozoa exhibited a distinct circular motility pattern. This was accompanied by hypo‐tyrosine phosphorylation of 45–60 kDa proteins, localized to the principal piece of the intact‐sperm and the outer dense fiber‐like structures in detergent treated‐sperm. Sperm kinematic analysis (by CASA) of spermatozoa, exhibiting circular motility (at 1st hr), showed lower values of straight line velocity, curvilinear velocity and average path velocity, compared to untreated controls. Other TP‐47 analogues, tyrphostin‐AG1478 and ‐AG1296, had no effect either on kinematic parameters or sperm protein tyrosine phosphorylation. These studies indicate that TP‐47‐induced circular motility of spermatozoa is compound‐specific and that the tyrosine phosphorylation status of 45–60 kDa flagellum‐localized proteins could be key regulators of sperm flagellar bending pattern, associated with the hyperactivation of hamster spermatozoa. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Interleaved acquisition of lipid and water images of the heart using a double‐inversion fast spin‐echo method
Authors: Altbach Maria I. , Li Zhiqiang , Bilgin Ali , Marcus Frank I. , Sorrell Vincent L. , Gmitro Arthur F. , Bluemke David A.
Published: October 2005

In this work we present a new method for the improved detection of lipid infiltration in the heart. The method employs a double‐inversion fast spin‐echo technique where the acquisition of water‐ and lipid‐suppressed k‐space data is alternated between TR periods to produce coregistered lipid and water images from data acquired in a breath hold. The lipid and water images can then be combined to generate a lipid/water image with reduced artifacts due to flow and excellent contrast between lipid and myocardium. The method is demonstrated in ex vivo tissue and in vivo. This novel method may improve the detection of lipid infiltration in the heart in pathologies such as arrhythmogenic right ventricular dysplasia. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Nuclear magnetic resonance parameters for monitoring coagulation of liver tissue
Authors: Carasso Dina , Eliav Uzi , Navon Gil
Published: October 2005

A new NMR parameter is suggested as a sensitive tool for monitoring thermal coagulation of liver tissue. That parameter is the proton magnetization exchange time (τMEX) between water and the proteins. τMEX was very sensitive to coagulation and insensitive to temperature, therefore representing only damage to the tissue, independent of effects caused by temperature fluctuations. The measurement of τMEX by two different methods revealed the existence of two or more groups of proteins, characterized by their different transverse relaxation time, and τMEX. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
T1ρ contrast in functional magnetic resonance imaging
Authors: Hulvershorn Justin , Borthakur Arijitt , Bloy Luke , Gualtieri Eugene E. , Reddy Ravinder , Leigh John S. , Elliott Mark A.
Published: October 2005

The application of T1 in the rotating frame (T1ρ) to functional MRI in humans was studied at 3 T. Increases in neural activity increased parenchymal T1ρ. Modeling suggested that cerebral blood volume mediated this increase. A pulse sequence named spin‐locked echo planar imaging (SLEPI) that produces both T1ρ and T2* contrast was developed and used in a visual functional MRI (fMRI)experiment. Spin‐locked contrast significantly augments the T2* blood oxygen level‐dependent (BOLD) contrast in this sequence. The total functional contrast generated by the SLEPI sequence (1.31%) was 54% larger than the contrast (0.85%) obtained from a conventional gradient‐echo EPI sequence using echo times of 30 ms. Analysis of image SNR revealed that the spin‐locked preparation period of the sequence produced negligible signal loss from static dephasing effects. The SLEPI sequence appears to be an attractive alternative to conventional BOLD fMRI, particularly when long echo times are undesirable, such as when studying prefrontal cortex or ventral regions, where static susceptibility gradients often degrade T2*‐weighted images. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Diagnostic discordance of electromyography (EMG) versus voiding cystourethrogram (VCUG) for detrusor‐external sphincter dyssynergy (DESD)
Authors: De Elise J.B. , Patel Chirag Y. , Tharian Brenda , Westney O. Lenaine , Graves Daniel E. , Hairston John C.
Published: October 2005

Aims

Detrusor sphincter dyssynergia (DSD) is defined as: “a detrusor contraction concurrent with an involuntary contraction of the urethral and/or periurethral striated muscle.” In neurogenic etiology, this usually refers to involuntary contraction of the external striated sphincter and has classically been termed detrusor‐external sphincter dyssynergia (DESD). There is currently no consensus regarding diagnosis [specifics of electromyographic (EMG) or voiding cystourethrographic (VCUG) determination], and little data on how well these modalities correlate. We explore the diagnostic congruence for DESD between needle EMG and VCUG in the neurogenic population.

Methods

Consecutive studies performed by a single urodynamicist at a major neurologic center were reviewed. Presence of DESD was determined by increased wire needle EMG activity and/or by dilated bladder neck and proximal urethra during detrusor contraction, in the absence of valsalva or attempt to inhibit voiding. Minimal acceptable criterion for agreement between the two tests was set at 70%.

Results

Fourty nine patients were diagnosed with DESD, had a videourodynamic study available, and had no history of sphincterotomy or stent. Binomial testing demonstrated significant disagreement (P < 0.000) in observed proportions. There was 60% agreement (28 patients) and 40% disagreement (21 patients) between EMG and VCUG for diagnosis of DESD.

Conclusions

We found significant disagreement between needle EMG and VCUG for a positive diagnosis of DESD. A combination of EMG and VCUG may identify more cases of DESD than either modality alone and underscores the need for more strict criteria when defining this entity from a urodynamic standpoint. Neurourol. Urodynam. © 2005 Wiley‐Liss, Inc.
Buckling of folded plate structures subjected to partial in‐plane edge loads by the FSDT meshfree Galerkin method
Authors: Liew K. M. , Peng L. X. , Kitipornchai S.
Published: October 2005

This paper presents a meshfree Galerkin method that is based on the first‐order shear deformation theory (FSDT) to study the elastic buckling behaviour of stiffened and un‐stiffened folded plates under partial in‐plane edge loads. The un‐stiffened folded plates are modelled as assemblies of flat plates. The stiffness and initial stress matrices of the flat plates are derived by the meshfree Galerkin method. A treatment is implemented to modify the stiffness and initial stress matrices, and the matrices are then superposed to obtain the stiffness and initial stress matrix of the entire folded plate. The analytical process for stiffened folded plates is similar, except that the effects of the stiffeners must be taken into account. Because no mesh is required, the proposed method is superior for studying problems that would involve remeshing in the finite element method. Several examples are employed to show the convergence and accuracy of the proposed method. The results obtained show good agreement with the results computed from the finite element analysis software ANSYS. Copyright © 2005 John Wiley & Sons, Ltd.
Comparative human and deer (Odocoileus virginianus) taphonomy at the Richards site, Ohio
Authors: Edgar H. J. H. , Sciulli P. W.
Published: October 2005

The Richards site is attributed to the Philo phase of the Fort Ancient tradition of the Ohio Valley area. Human skeletal material from the site shows evidence of peri‐ and post‐mortem taphonomic changes, including cut marks, burning and fracturing. Previous analyses have discussed explanations for these changes, including secondary burial, ritual destruction and cannibalism. Researchers have theorised that, allowing for differences in anatomy among species, humans and animals butchered for the same purpose (consumption) will show similar patterns of taphonomic changes associated with butchery. The human remains at the Richards Site were disposed in general midden pits containing mixed cultural debris and faunal remains. White‐tailed deer (Odocoileus virginianus) constitutes approximately 60% of all the faunal bone, indicating that it was a major food resource. To test a cannibalism explanation, a comparative analysis of human‐induced taphonomy in human and deer skeletal remains was performed, using chi‐square and odds ratio tests. If humans were being used as a food resource, the pattern of butchery seen would mirror that of the deer. The analysis described here compares the patterns of treatment and disposal of human and deer skeletal elements at the Richards site, to test whether both species were used as food resources.

Similar types of evidence for human‐induced taphonomic changes, including cutting, chopping, burning and breakage, can be seen in both species. However, results indicate that, in general, human remains show much more evidence of perimortem treatment than do deer remains. In fact, the common odds ratio for perimortem treatment in all bones is 3.25, indicating that a human bone is 3.25 times as likely as a deer bone to be affected by burning, cutting or chopping. This probably indicates that perimortem treatment of humans was greater than that necessary simply for butchering for consumption. Copyright © 2005 John Wiley & Sons, Ltd.
Positive Support Strategies for Students with Behavioral Disorders in General Education Settings
Authors: Hieneman Meme , Dunlap Glen , Kincaid Donald
Published: October 2005

Although it has been argued that students with behavioral disorders benefit most from placement in general education classrooms, careful and systematic support is required to insure that their placement is successful. In this article, we review supports and interventions provided at multiple levels that together are known as “positive behavior support” (PBS). The levels include school‐wide PBS, which involves the full student body; classroom‐based PBS, focusing on the individual class as the unit of analysis; and individualized PBS, addressing the individualized needs of specific students. When relatively intense and chronic behavior problems exist, individualized PBS involves the use of functional behavioral assessments and proactive, educative interventions. In this article, we describe each of these levels with reference to the empirical literature and with an emphasis on practical applications. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 779–794, 2005.
Using Curriculum‐Based Measurement to Improve Student Achievement: Review of Research
Authors: Stecker Pamela M. , Fuchs Lynn S. , Fuchs Douglas
Published: October 2005

This review examines the efficacy of curriculum‐based measurement (CBM) as an assessment methodology for enhancing student achievement. We describe experimental‐contrast studies in reading and mathematics in which teachers used CBM to monitor student progress and to make instructional decisions. Overall, teachers' use of CBM produced significant gains in student achievement; however, several critical variables appeared to be associated with enhanced achievement for students with disabilities: teachers' use of systematic data‐based decision rules, skills analysis feedback, and instructional recommendations for making program modifications. In general education, positive effects for CBM were associated with use of class profiles and implementation of peer‐assisted learning strategies. Implications for instructional practice and future applications of CBM are described. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 795–819, 2005.
Curriculum and Assessment Considerations for Young Children from Culturally, Linguistically, and Economically Diverse Backgrounds
Authors: Espinosa Linda M.
Published: October 2005

Early childhood educators and school personnel increasingly will be working with children and families from diverse economic, ethnic, cultural, and linguistic backgrounds. While the student population is rapidly becoming diverse, the teaching force remains predominantly White and from middle‐class backgrounds (Whitebook, 2003). This growing cultural and linguistic discrepancy between the children enrolled and the teachers who teach them underscores the need for all educators to develop the skills, knowledge, and, most importantly, the attitudes to effectively teach in multicultural and multilingual settings. Children from different cultures and low‐income households who enter school programs speaking little or no English are highly vulnerable to chronic academic underachievement and eventual school failure. Recent research has revealed dramatic differences in young children's achievement in mathematics and literacy by race, ethnicity, and socioeconomic status (SES) at school entry (V. Lee & D. Burkam, 2002). This article reviews the relevant research on effective teaching and assessment practices for young children from diverse backgrounds and offers recommendations for school personnel. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 837–853, 2005.
The Disconnect of Poor‐Urban Education: Equal Access and a Pedagogy of Risk Taking
Authors: Belfiore Phillip J. , Auld Ruth , Lee David L.
Published: October 2005

In an age of educational accountability and school competition, the gap between current poor‐urban school performance and standards of excellence remains glaringly obvious. As poor‐urban schools scramble to “close the gap,” many abandon sound pedagogy, becoming entrenched in a curriculum where basic‐skills worksheets are the primary method of educational delivery resulting in a disconnect between pedagogically sound educational practices and those very students that need it most. Two literacy pilot programs are discussed as applied examples showing that good teaching and accountability result in increases in early reading skills as measured by the Woodcock Reading Mastery Test‐Revised (R.W. Woodcock, 1998). Results are discussed in light of raised teacher expectations, assessment‐driven small class grouping, and active student learning. In a supportive, challenging environment, the basis for a pedagogy of risk taking emerges. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 855–863, 2005.
PRIDE: The proteomics identifications database (vol. 5, Issue 13, pp. 3537‐3545)
Authors: Martens Lennart , Hermjakob Henning , Jones Philip , Adamski Marcin , Taylor Chris , States David , Gevaert Kris , Vandekerckhove Joël , Apweiler Rolf
Published: October 2005

See original http://dx.doi.org/10.1002/pmic.200401303
Living polymerization of substituted acetylenes
Authors: Mayershofer Martin G. , Nuyken Oskar
Published: October 2005

For many years, considerable research efforts have been dedicated to π‐conjugated polymers because of their extraordinary electronic, optical, and structural properties. The employed transition‐metal‐based initiating systems comprise not only simple transition‐metal salts but also rather sophisticated mixtures of two, three, or four compounds and even highly defined single‐component systems such as transition‐metal alkylidene complexes. Extensive fine‐tuning of the electronic and steric properties of initiator–monomer systems eventually allowed the tailor‐made synthesis of conjugated materials via living polymerization techniques. This article focuses on recent developments in the field of the living polymerization of substituted acetylene derivatives. Ill‐defined group 5 and 6 transition metal halide‐based initiators, well‐defined transition‐metal alkylidene complexes, and rhodium(I)‐based systems that induce the living polymerization of numerous substituted acetylenes are reviewed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5723–5747, 2005
Tetramethylguanidino‐tris(2‐aminoethyl)amine: A novel ligand for copper‐based atom transfer radical polymerization
Authors: Brar A. S. , Kaur Sukhdeep
Published: October 2005

With CuBr/tetramethylguanidino‐tris(2‐aminoethyl)amine (TMG3‐TREN) as the catalyst, the atom transfer radical polymerization (ATRP) of methyl methacrylate, n‐butyl acrylate, styrene, and acrylonitrile was conducted. The catalyst concentration of 0.5 equiv with respect to the initiator was enough to prepare well‐defined poly(methyl methacrylate) in bulk from methyl methacrylate monomer. For ATRP of n‐butyl acrylate, the catalyst behaved in a manner similar to that reported for CuBr/tris[2‐(dimethylamino)ethyl]amine. A minimum of 0.05 equiv of the catalyst with respect to the initiator was required to synthesize the homopolymer of the desired molecular weight and low polydispersity at the ambient temperature. In the case of styrene, ATRP with this catalyst occurred only when a 1:1 catalyst/initiator ratio was used in the presence of Cu(0) in ethylene carbonate. The polymerization of acrylonitrile with CuBr/TMG3‐TREN was conducted successfully with a catalyst concentration of 50% with respect to the initiator in ethylene carbonate. End‐group analysis for the determination of the high degree of functionality of the homopolymers synthesized by the new catalyst was determined by NMR spectroscopy. The isotactic parameter calculated for each system indicated that the homopolymers were predominantly syndiotactic, signifying that the tacticity remained the same, as already reported for ATRP. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5906–5922, 2005
The effective action of type II Calabi‐Yau orientifolds
Authors: Grimm T.W.
Published: October 2005

This article first reviews the calculation of theN= 1 effective action for generic type IIA and type IIB Calabi‐Yau orientifolds in the presence of background fluxes by using a Kaluza‐Klein reduction. The Kähler potential, the gauge kinetic functions and the flux‐induced superpotential are determined in terms of geometrical data of the Calabi‐Yau orientifold and the background fluxes. As a new result, it is shown that the chiral description directly relates to Hitchin's generalized geometry encoded by special odd and even forms on a threefold, whereas a dual formulation with several linear multiplets makes contact to the underlyingN= 2 special geometry. In type IIB setups, the flux‐potentials can be expressed in terms of superpotentials, D‐terms and, generically, a massive linear multiplet. The type IIA superpotential depends on all geometric moduli of the theory. It is reviewed, how type IIA orientifolds arise as a special limit of M‐theory compactified on specificG2manifolds by matching the effective actions. In a similar spirit type IIB orientifolds are shown to descend from F‐theory on a specific class of Calabi‐Yau fourfolds. In addition, mirror symmetry for Calabi‐Yau orientifolds is briefly discussed and it is shown that theN= 1 chiral coordinates linearize the appropriate instanton actions.
Reactivity investigation of mixtures of propane and nitrous oxide
Authors: Willey Ronald J. , Hu Shangwei , Moses John M.
Published: October 2005

Supercritical and vapor‐phase reactions of oxidizers and fuels under pressure are of commercial interest. Because mixtures of propane and nitrous oxide have the potential to be explosive, a model mixture was studied with the intent of defining safe operating boundaries. This work investigated the nitrous oxide/propane oxidant/fuel system, diluted with the inert solvent carbon dioxide, and a catalyst as an accelerant, to determine the safe operating regions for the oxidation reaction. Using an ARC® calorimeter for the evaluations, variables included initial system density, catalyst, and mixture compositions. Density of the system ranged from 0.05 to 0.62 g/cm3. A number of catalysts were investigated with 10% Pd on carbon being the most active. Strongest reactivity was observed when the mixture was stoichiometric to the complete combustion products of nitrogen, carbon dioxide, and water. Three distinct regions of reactivity were observed: mild reactivity (starting at the sensitivity of the ARC of dT/dt = 0.02 to about 0.1° C/min); strong exothermic reaction (dT/dt ≅ 1° C/min); and flammable and/or explosive (a distinct and substantial jump in dP/dt in <1 s). As a result, a boundary has been proposed for safe mixtures of nitrous oxide, propane, and carbon dioxide, and a basis for determining safe operating compositions for other systems. The computed adiabatic reaction temperature was used to correlate the experimental results to establish the boundary for safe operation. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Durability of GFRP bars: a critical review of the literature
Authors: Nkurunziza Gilbert , Debaiky Ahmed , Cousin Patrice , Benmokrane Brahim
Published: October 2005

The research undertaken during the last two decades has shown that one of the potential solutions to the steel‐corrosion‐related problems in concrete is the use of fiber‐reinforced composite (FRP) reinforcement as a replacement for traditional steel bars. Glass FRP (GFRP) reinforcement is gaining more popularity in construction of bridges and in other concrete structures because of its low cost compared to Carbon FRP reinforcement. The durability of these materials, especially under severe environmental conditions, is now recognized as the most critical topic of research. The lack of data on durability of the GFRP reinforcements is a major obstacle to their acceptance on a broader scale in civil engineering.

This paper summarizes the most significant research work published on the durability of FRP bars in the past two decades. A comprehensive review of the literature on the durability of FRP bars indicates a significant increase in the number of studies in this area in the last decade. The durability tests conducted by the authors and others on the latest generation of GFRP bars subjected to stresses higher than the design limits, combined with aggressive mediums at elevated temperatures, have concluded that the strength reduction factors adopted by current codes and guidelines are conservative. These factors were based on limited test results that were carried out on the early generations of the GFRP products, which have now substantially changed.
Electrochemical stabilization of crystalline silicon with aromatic self‐assembled monolayers in aqueous electrolytes
Authors: Tutus Murat , Purrucker Oliver , Adlkofer Klaus , Eickhoff Martin , Tanaka Motomu
Published: October 2005

We report stable chemical engineering of hydrogen‐terminated Si[111] surfaces in aqueous electrolytes by electrochemical grafting of aromatic monolayers. The topography and free energy of the engineered surface obtained from AFM and contact angle measurements confirmed homogeneous coating of the surface with a monolayer. Grafting of monolayers actually resulted in a clear suppression of the surface defect densities, demonstrated by photoluminescence lifetime. Changes in the surface chemical identities after grafting and post‐treatments were followed by X‐ray photoelectron spectroscopy (XPS). The electrochemical stability in aqueous electrolytes was assessed by impedance spectroscopy, revealing an improved stabilization of the Si/electrolyte interface by the grafted monomolecular film. This protocol was further applied for another aromatic compound, where the impact of 4‐substituent functions could clearly be detected by photovoltage measurements. The chemical and electrochemical stability achieved here is promising for the successive deposition of biocompatible polymer films and lipid membranes. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parallelization of the quantum dynamics code for cluster architecture and its applications to the Gross–Pitaevskii equation
Authors: Gorecki Adam , Bala Piotr , Lesyng Bogdan
Published: October 2005

We present a parallel version of a quantum dynamics (QD) algorithm in a wave function representation. The algorithm has been optimized for a Linux cluster as well as for Cray T3E, using a parallel version of a three‐dimensional FFT library. We have applied this algorithm for solving the nonlinear Gross–Pitaevskii equation (GPE), which describes the evolution of Bose–Einstein condensates (BEC) in the mean field approximation. Our method reduces the computational time and allows the study of nonlinear quantum systems. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Bulk and compound‐specific isotopic characterisation of illicit heroin and cling film
Authors: Idoine Fay A. , Carter James F. , Sleeman Richard
Published: October 2005

Comparative analysis involves various but complementary methods and can be used for forensic intelligence purposes to group seizures of heroin into batches. Much forensic analysis now combines expertise in the traditional area of drugs investigation with a detailed understanding of supply, packaging, distribution, and drugs intelligence. It was the intention of this research to determine whether illicit heroin seizures and packaging material can be grouped according to isotopic compositions, and to explore factors that affect the isotopic compositions. In order to achieve these aims, 14 samples of seized heroin, thirteen provided by Avon and Somerset Constabulary (UK), were analysed by elemental analysis/isotope ratio mass spectrometry (EA/IRMS) and gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) for carbon and hydrogen isotopes. These tests elucidated that a combination of theδ13C,δ15N,δ18O andδ2H results from EA/IRMS is able to distinguish between most samples of bulk heroin. We speculate that theδ13C values of the alkaloids, obtained by GC/C/IRMS, give indications of different geographical or temporal origins of some of the heroin samples. GC/C/IRMS of the cutting agent, caffeine, provides a means to link dilution events. Fifteen retail cling film samples and seven cling film samples from heroin seizures were analysed by EA/IRMS. A multivariate comparison of the carbon, hydrogen and oxygen isotope ratios was able to distinguish between most of the samples. This technique enabled the cling films from the heroin to be grouped according to seizure. Three solvents were tested on two samples of cling film of known composition. Methanol and chloroform were both found to extract material from PVC and from non‐PVC cling films. Water‐treated PVC was indistinguishable from the untreated PVC and thus water was found to be the most suitable solvent when washing cling film prior to IRMS analysis. Copyright © 2005 John Wiley & Sons, Ltd.
The natural abundance of 13C, 15N, 34S and 14C in archived (1923–2000) plant and soil samples from the Askov long‐term experiments on animal manure and mineral fertilizer
Authors: Bol Roland , Eriksen Jorgen , Smith Pete , Garnett Mark H. , Coleman Kevin , Christensen Bent T.
Published: October 2005

The Askov field experiment (Denmark), established in 1894, provides a unique opportunity to examine long‐term effects of animal manure and mineral fertilizer on soil organic matter quality and turnover. This sandy loam soil is classified as Alfisol (Typic Hapludalf). Soil C, N, S, 13C, 15N, 34S and 14C contents were measured in a selection of archived soil samples (1923, 1938, 1945, 1953, 1964, 1976, 1985, 1996 and 2000) from unfertilized (O), animal manure (1 AM) and mineral fertilizer (1 NPK) treatments. These treatments are imbedded in a four‐course crop rotation of winter cereals, root crops, spring cereals and a clover/grass mixture. The contents of C, N, S, 13C, 15N and 34S in selected crop samples (1953–1996) and in contemporary samples of animal feed and manure were also determined. Temporal soil nutrient and isotope trends between fertilizer treatments were significantly different, except for S content in 1 AM and 1 NPK. The total soil C and S was higher in 1 AM and 1 NPK than in the O treatment. The total soil N content (1 AM > 1 NPK > O) and the δ15N content (1 AM > 1 NPK and O) were also different. Analyses of plant, animal feed and manures confirmed that differences in soil 15N values were related to δ15N values of added source inputs. Soil and crop δ13C values were similar, but manures had slightly lower values. The variation of soil δ34S (and total S) from 1923 to 1996 was larger in the O than 1 AM and 1 NPK plots reflecting changes in atmospheric S inputs. The total contents of soil C, N and S were significantly correlated, but their isotopic signatures were not, suggesting that the C, N, S turnovers in soil are subject to different controls. The 14C content was generally higher in the 1 AM than 1 NPK and O, with bomb‐14C incorporation modelling indicating that mean residence time (MRT) was ca. 170 years in the 1 AM, but closer to 250–290 years in the 1 NPK and O treatments. The measured trends in soil C and 14C during 1923–1996 were successfully modelled using the RothC model. The OM accumulation in the Askov soils was generally dominated by microbial decomposition products rather than by recalcitrant components of the various inputs. Copyright © 2005 John Wiley & Sons, Ltd.
Determination of steroid hormones, hormone conjugates and macrolide antibiotics in influents and effluents of sewage treatment plants utilising high‐performance liquid chromatography/tandem mass spectrometry with electrospray and atmospheric pressure chemical ionisation
Authors: Schlüsener Michael P. , Bester Kai
Published: October 2005

In this study we present a high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) method which has been elaborated to analyse steroid hormones, hormone conjugates, oral contraceptives and macrolide antibiotics unchanged in unfiltered influents and effluents of sewage treatment plants (STPs). HPLC separation of the steroid hormones was achieved in 35 min, as well as those of the antibiotics. The analytes were extracted by solid‐phase extraction, followed by clean‐up using size exclusion chromatography (SEC). For the final quantification HPLC/MS/MS was used. The two ionisation modes, electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI), in HPLC/MS/MS were compared for the analysis of steroid hormones. For quantitative results drastic matrix effects were observed while using ESI. These effects were less pronounced while using APCI. These pitfalls were additionally reduced by clean‐up using SEC as well as isotope dilution. Additionally, two multiple reaction monitoring (MRM) transitions per compound were used to prevent false positive results. Recovery experiments with spiked tap water with concentrations varying from 1 to 1000 ng/L gave constant recovery rates: The recovery rates for the hormones and conjugates ranged from 58 to 107%, those of the contraceptives ranged from 83 to 109%. The relative standard deviation was found to be 7 to 24% and the limits of detection were 0.1 to 4.5 ng/L. The recovery rates of the macrolide antibiotics ranged from 76 to 103%, while the relative standard deviation was found to be 7 to 14% and the limits of detection ranged from 0.6 to 1.8 ng/L. The maximum concentrations found in influents of a STP was 470 ng/L for estriol and 1200 ng/L for erythromycin. Copyright © 2005 John Wiley & Sons, Ltd.
A novel dual‐isotope labelling method for distinguishing between soil sources of N2O
Authors: Wrage N. , Groenigen J. W. van , Oenema O. , Baggs E. M.
Published: October 2005

We present a novel 18O‐15N‐enrichment method for the distinction between nitrous oxide (N2O) from nitrification, nitrifier denitrification and denitrification based on a method with single‐ and double‐15N‐labelled ammonium nitrate. We added a new treatment with 18O‐labelled water to quantify N2O from nitrifier denitrification. The theory behind this is that ammonia oxidisers use oxygen (O2) from soil air for the oxidation of ammonia (NH3), but use H2O for the oxidation of the resulting hydroxylamine (NH2OH) to nitrite (NO). Thus, N2O from nitrification would therefore be expected to reflect the 18O signature of soil O2, whereas the 18O signature of N2O from nitrifier denitrification would reflect that of both soil O2 and H2O. It was assumed that (a) there would be no preferential removal of 18O or 16O during nitrifier denitrification or denitrification, (b) the 18O signature of the applied 18O‐labelled water would remain constant over the experimental period, and (c) any O exchange between H218O and NO would be negligible under the chosen experimental conditions. These assumptions were tested and validated for a silt loam soil at 50% water‐filled pore space (WFPS) following application of 400 mg N kg−1 dry soil. We compared the results of our new method with those of a conventional inhibition method using 0.02% v/v acetylene (C2H2) and 80% v/v O2 in helium. Both the 18O‐15N‐enrichment and inhibitor methods identified nitrifier denitrification to be a major source of N2O, accounting for 44 and 40%, respectively, of N2O production over 24 h. However, compared to our 18O‐15N‐method, the inhibitor method overestimated the contribution from nitrification at the expense of denitrification, probably due to incomplete inhibition of nitrifier denitrification and denitrification by large concentrations of O2 and a negative effect of C2H2 on denitrification. We consider our new 18O‐15N‐enrichment method to be more reliable than the use of inhibitors; it enables the distinction between more soil sources of N2O than was previously possible and has provided the first direct evidence of the significance of nitrifier denitrification as a source of N2O in fertilised arable soil. Copyright © 2005 John Wiley & Sons, Ltd.
The effect of growth rate on tissue‐diet isotopic spacing in rapidly growing animals. An experimental study with Atlantic salmon (Salmo salar)
Authors: Trueman Clive N. , McGill Rona A. R. , Guyard Philippe H.
Published: October 2005

The difference in isotopic composition between a consumer's tissues and that of its diet is a critical aspect of the use of stable isotope analyses in ecological and palaeoecological studies. In a controlled feeding experiment with the Atlantic salmon, Salmo salar, we demonstrate for the first time that the value of tissue‐diet isotope spacing in nitrogen in a growing animal is not constant, but varies inversely with growth rate. The value of tissue‐diet isotopic spacing in N reflects N use efficiency. Thus, in salmon, growth rate is accompanied by, or requires, increased N use efficiency. The total range in tissue‐diet isotopic spacing in N seen in the experimental population of 25 fish was 1‰, approximately 50% of the total trophic shift. Mean equilibrium tissue‐diet isotopic spacing (±standard deviation) in salmon averaged 2.3‰ (±0.3‰) and 0.0‰ (±0.3‰) for N in muscle and liver, respectively, and 2.1‰ (±0.1‰) and 1.6‰ (±0.3‰) for C in muscle and liver, respectively. Feeding with a mixed dietary source (wheat and fish‐meal origin) resulted in tissue‐diet isotopic fractionation in both C and N due to the differential digestibility of food components with distinct isotopic composition. The rate of change in isotopic composition of S. salar tissues was dominated by growth, but the estimated contribution of metabolic turnover to change in tissue N was relatively high for an ectothermic animal at ca. 20–40%. The estimated half‐life for metabolic turnover of the tissue N pool was ca. 4 months in both muscle and liver tissue. This is the first study to demonstrate a direct relationship between tissue‐diet isotopic spacing in N and growth rate and adds to the growing list of factors known to influence the level of isotopic separation between a consumer's tissue and that of its diet. Copyright © 2005 John Wiley & Sons, Ltd.
Harnessing the transient signals in atomic force microscopy
Authors: Sahoo Deepak R. , Sebastian Abu , Salapaka Murti V.
Published: October 2005

In the existing dynamic‐mode operation of atomic force microscopes (AFMs) steady‐state signals like amplitude and phase are used for detection and imaging of material. Due to the high quality factor of the cantilever probe the corresponding methods are inherently slow. In this paper, a novel methodology for fast interrogation of material that exploits the transient part of the cantilever motion is developed. This method effectively addresses the perceived fundamental limitation on bandwidth due to high quality factors. It is particularly suited for the detection of small time scale tip–sample interactions. Analysis and experiments show that the method results in significant increase in bandwidth and resolution as compared to the steady‐state‐based methods. This article demonstrates the effectiveness of a systems perspective to the field of imaging at the nano‐scale and for the first time reports realtime experimental results and scanning applications of the transient method. Copyright © 2005 John Wiley & Sons, Ltd.
Statistical properties and inference of the antimicrobial MIC test
Authors: Annis David H. , Craig Bruce A.
Published: October 2005

A common method for measuring the drug‐specific minimum inhibitory concentration (MIC) of an antibacterial agent is via a two‐fold broth dilution test known as the MIC test. Because this procedure implicitly rounds data upward, inference based on unadjusted measurements is biased and overestimates bacterial resistance to a drug. We detail this test procedure and its associated bias, which, in many cases, has an expected value of approximately 0.5 on the log2scale. In addition, new bias‐corrected estimates of resistance are proposed. A numeric example is used to illustrate the extent to which the traditional resistance estimate can overestimate the true proportion of resistant strains, a phenomenon which is remedied by using the proposed estimates. Published in 2005 by John Wiley & Sons, Ltd.