bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian Estimation from Censored Data with Incomplete Information
Authors: Phillips M. J.
Published: March 2004

Phillips and Sweeting (Journal of the Royal Statistical Society B 1996; 58:775–783) considered estimation of the parameter of the exponential distribution with censored failure time data when there is incomplete knowledge of the censoring times. It was shown that, under particular models for the censoring mechanism and censoring errors, it will usually be safe to ignore such errors provided they are not expected to be too large. The results depended on using an inverted Gamma model for the conditional distribution of the concomitant variable which provided the supplementary information used when the failure times were censored. The effect of alternative assumptions about knowledge of the censoring values on the estimation of failure rate is investigated through the use of Bayesian analysis. By putting prior distributions on the critical parameters of the censoring mechanism it is possible to incorporate and investigate the influence of the use of prior knowledge. Copyright © 2004 John Wiley & Sons, Ltd.
Linear and nonlinear feature of electronic excitation energy in carbon chains HC2n+1H and HC2nH
Authors: Zhang Congjie , Cao Zexing , Wu Haishun , Zhang Qianer
Published: March 2004

Density functional theory has been used to investigate the geometries, bonding, and vibrational frequencies of HC2nH (n = 1–13) and HC2n+1H (n = 2–12). Vertical excitation energies for the X1Σ → 11Σ transition of HC2nH (n = 1–5) and for the X3Σ → 13Σ transition of HC2n+1H (n = 2–5) have been calculated by the time‐dependent density functional theory and ab initio second‐order multiconfiguration perturbation method, respectively. On the basis of the present calculations, explicit expressions for the size dependence of excitation energy in linear polyynes HC2n+1H and HC2n+1H are suggested. Such analytical λ − n relationships show good agreement with experimental observations. Theoretical investigations of relevant excited states demonstrate that distinct linear and nonlinear spectroscopic features in such polyynes can be ascribed to similarity and difference in bonding between the ground and excited states in HC2n+1H and HC2nH. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Approximate atomic calculations and stability of negative ions with a modified Thomas–Fermi–Dirac model
Authors: Porras Ignacio , Moya Andrés
Published: March 2004

By means of an improved modified Thomas–Fermi–Dirac approach we obtain fair shell‐averaged total energies of atoms and ions. In particular, stable single‐charged negative ions can be described with this method. In addition, the possibility of developing hybrid schemes with this method coupled to quantum mechanical calculations for the evaluation of quantities such as ionization potentials is also investigated. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
JWKB method as an exact technique
Authors: Shen Hujun , Silverstone Harris J.
Published: March 2004

The JWKB method involves divergent asymptotic expansions in powers of ħ. Borel summability turns divergence into convergence, leading to exact solutions of the Schrödinger equation. The formulas that connect real solutions across linear turning points, where the terms of the expansion are singular, are complex but nonunidirectional. A series of basic problems constructed from linear potentials—for which the JWKB solutions are simple, in which the boundary conditions and physics differ, but for which the turning points are the same—is used to demonstrate the nondirectionality of the turning points and how “Borel sum approximants” lead to exact energy eigenvalues. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Bicyclopropylidene radical cation: A rehybridization ring opening to tetramethyleneethane
Authors: Norberg Daniel , Larsson Per‐Erik , Dong Xi‐Cheng , Salhi‐Benachenhou Nessima , Lunell Sten
Published: March 2004

A computational study has been undertaken to elucidate the mechanism of the bicyclopropylidene radical cation (BCP•+) rearrangement into the tetramethyleneethane radical cation (TME•+). A stepwise mechanism is found for the first ring opening, with an activation energy of 7.3 kcal mol−1, while the second ring opening proceeds with no activation energy. Each ring opening is combined with a striking pyramidalization of one carbon atom in the central bond. In a natural bond orbital (NBO) analysis, the dominating reaction coordinate during the ring opening is found to be the olefinic carbon atom rehybridization, which also favors the continued bond breaking. Widely different ESR parameters are computed for the two sets of four protons in BCP•+, in excellent agreement with the observed spectrum, which are interpreted in the NBO analysis in terms of two hyperconjugative effects. Two minimum energy structures are located for TME•+, separated by a cusp on the internal rotation path of this cation, both of which show ESR parameters in good agreement with the observed spectrum for TME•+. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Semi‐classical formulation of time‐dependent discrete variable representation method
Authors: Puzari Panchanan , Adhikari Satrajit
Published: March 2004

In this article, we apply a novel time‐dependent discrete variable representation (TDDVR) method proposed by Barkakaty and Adhikari to investigate tunneling through an Eckart barrier. This semi‐classical method is theoretically rigorous and straightforward to implement. Among the TDDVR formulations, this report presents the first derivation of a rigorous form of quantum force (QF) for the present perspective. The validity of this semi‐classical approach is demanded based on the excellent agreement of the tunneling probability with the corresponding quantum results. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Liquid supports for ultraviolet atmospheric pressure matrix‐assisted laser desorption/ionization
Authors: Turney Kevin , Harrison W. W.
Published: March 2004

Atmospheric pressure (AP) liquid matrices for ultraviolet (UV) matrix‐assisted laser desorption/ionization (MALDI) are presented. Doping a known organic chromophore, α‐cyano‐4‐hydroxycinnamic acid (CHCA), into liquid media yielded a homogenous sample system with simplified sample preparation, increased sample lifetime, and added utility for APMALDI ion sources. Compared with vacuum situations, AP matrices are not as limited by vapor pressure, so liquid matrix formulations can focus on desorption and ionization versus vacuum stability and source contamination. The parameters studied include chromophore concentration, liquid support variations, and quantitation capability. Chromophore concentration adjustments provided insight into the necessary absorbance for UV‐APMALDI and demonstrated the importance of laser penetration depth. Liquid support variations allowed adjustments of sample lifetime and analyte solvents. Extended sample lifetime is beneficial for instrument tuning and source optimization; however, increased liquid viscosity lowers signal intensity. The shot‐to‐shot reproducibility, as examined with individual ion packets, suggests that the liquid matrix can alleviate some inconsistencies seen with solid MALDI, suggesting a possibility for better quantitation. The measurements for laser penetration depth, solution viscosity, and solvent additives could add to the information on MALDI mechanisms. The liquid matrix offers advantages that complement current MALDI methods. Copyright © 2004 John Wiley & Sons, Ltd.
A sensitive method for the determination of the novel cholinesterase inhibitor ZT‐1 and its active metabolite huperzine A in rat blood using liquid chromatography/tandem mass spectrometry
Authors: Li Chuan , Du Feifei , Yu Chen , Xu Xing , Zheng Jiang , Xu Fang , Zhu Dayuan
Published: March 2004

ZT‐1 has been developed as a novel acetylcholinesterase inhibitor, but is rapidly degraded to huperzine A (Hup A) in water or aqueous organic solvents. A sensitive method has been developed for simultaneous determination of ZT‐1 and its active metabolite Hup A in blood, and was applied to the investigation of the pharmacokinetics of ZT‐1 in rats. The method involves immediate hydrogenation of ZT‐1 with sodium borohydride to the stable form rZT‐1 following blood sampling. The NaBH4‐treated blood sample is then submitted to liquid‐liquid extraction, and the resultant extract is analyzed by liquid chromatography with electrospray ionization and tandem mass spectrometry. Huperzine B is used as internal standard for the quantification. ZT‐1 was found to be rapidly absorbed in the intestinal tract, with a time to reach the peak blood concentration (Tpeak) of 5 min after an intragastric dose of ZT‐1 embedded in povidone to rats at 0.5 mg ZT‐1/kg. The mean maximum blood concentration (Cmax) and area under the blood level‐time curve (AUC0 → 8) of ZT‐1 were 1.57 ng/mL and 0.48 ng · h/mL, respectively. The Tpeak, Cmax, and AUC values of the metabolite Hup A were 0.22 h, 109.9 ng/mL, and 96.3 ng · h/mL, respectively. Following an intravenous dose of 0.1 mg ZT‐1/kg rat body weight, the blood concentration of ZT‐1 was higher than that of Hup A, and the AUC0 → 8 values were 26.2 ng · h/mL for ZT‐1 and 6.0 ng · h/mL for Hup A. The elimination half‐lives (T1/2) of ZT‐1 and Hup A were 0.68 and 1.47 h, respectively. The oral bioavailability (F) of intact ZT‐1 in rats treated with ZT‐1 embedded in povidone was very low, 0.37%. Copyright © 2004 John Wiley & Sons, Ltd.
Analysis of betamethasone, dexamethasone and related compounds by liquid chromatography/electrospray mass spectrometry
Authors: Arthur Kathryn E. , Wolff Jean‐Claude , Carrier Dan J.
Published: March 2004

A reversed‐phase high‐performance liquid chromatography/electrospray ionisation mass spectrometry (HPLC/ESI‐MS) method has been developed to conclusively differentiate the epimers betamethasone and dexamethasone and various esterification products (betamethasone and dexamethasone 21‐acetate, betamethasone and dexamethasone 21‐phosphate, betamethasone 17‐valerate, betamethasone 21‐valerate and betamethasone 17,21‐dipropionate) in counterfeit drugs. Good separation with baseline resolution of all epimers or isomers was obtained on a Zorbax Eclipse XDB or Luna C8 column, using a step gradient with mobile phases of 0.05 M ammonium acetate and acetonitrile. Betamethasones can also be distinguished by the relative abundance of their m/z 279 ion in the positive electrospray tandem mass spectra. The LC/MS or LC/MS/MS method developed was successfully applied to the analysis of drug product samples, i.e. creams and tablets. Copyright © 2004 John Wiley & Sons, Ltd.
Using a non‐invasive stable isotope tracer to measure the absorption of water in humans
Authors: Hill Rebecca J. , Bluck Leslie J. C. , Davies Peter S. W.
Published: March 2004

The development of solutions that prevent dehydration or promote adequate re‐hydration play a vital role in preventing fatigue during exercise, however, the methods commonly used to assess the hydration ability of such solutions are invasive and often assess the components of absorption separately. This paper describes using a non‐invasive deuterium tracer technique that assesses gastric emptying and intestinal absorption simultaneously to evaluate the uptake of water during rest and exercise. The kinetics of absorption are further examined by mathematical modelling of the data generated. For the rest group, 0.05 g/kg of body weight of deuterium, contained in gelatine capsules, was ingested with ordinary tap water and saliva samples were collected every 5 min for one hour while the subject remained seated. The deuterium was administered as above for the exercise group but sample collection was during one hour of exercise on a treadmill at 55% of the subject's maximum heart rate. The enrichment data for each subject were mathematically modelled and the parameters obtained were compared across groups using an independent samples t‐test. Compared with the rest condition, the exercise group showed delayed absorption of water as indicated by significant differences for the modelling parameters t2, t½, maximum absorption rate and solution absorption amount at t1. Labelling with a deuterium tracer is a good measure of the relative rate ingested fluids are absorbed by the body. Mathematical modelling of the data generates rates of maximum absorption and allows calculation of the percentage of the solution that is absorbed at any given time during the testing period. Copyright © 2004 John Wiley & Sons, Ltd.
Determination of triforine using high‐performance liquid chromatography with tandem mass spectrometry
Authors: Harrold Julie A. , Sykes Mark D. , Goodrum Martin , Fussell Richard J.
Published: March 2004

A method for determination of triforine using high‐performance liquid chromatography with electrospray tandem mass spectrometry was developed. A simple ethyl acetate extraction with solvent exchange into water/methanol was used for sample preparation. The method was validated at 0.01 and 0.05 mg kg−1 levels in apple, tomato and tinned blackcurrants. Recoveries were in the range 56.6–99.8% and no matrix suppression or enhancement effects were observed. © Crown Copyright 2004. Reproduced with the permission of Her Majesty's Stationary Office. Published by John Wiley & Sons, Ltd.
Co‐ordinated control design of generator excitation and SVC for transient stability and voltage regulation enhancement of multi‐machine power systems
Authors: Cong L. , Wang Y. , Hill D. J.
Published: March 2004

This paper presents a co‐ordinated control scheme for generator excitation and a static var compensator (SVC) to achieve transient stability, adequate damping and voltage regulation enhancement of multimachine power systems. By using the feedback linearization technique, the nonlinearities of the generator and the SVC model are cancelled. With the help of robust control theory, the interconnection between controllers, the variation of system structure and the parameter uncertainties are taken into consideration in the controller design. Only local measurements are required. Simulation results obtained from a three‐machine, one‐SVC example system show that the proposed controllers can provide good stability, voltage control and damping over a wide range of operating conditions. Copyright © 2004 John Wiley & Sons, Ltd.
Adaptive nonlinear output feedback for transient stabilization and voltage regulation of power generators with unknown parameters
Authors: Damm Gilney , Marino Riccardo , Lamnabhi‐Lagarrigue Françoise
Published: March 2004

This work presents a nonlinear adaptive output feedback excitation control, designed for a synchronous generator modelled by a standard third‐order model on the basis of the physically available measurements of relative angular speed, active and reactive electric power and terminal voltage. The power angle, which is a crucial variable for the excitation control, as well as mechanical power and the impedance of the transmission line connecting the generator to an infinity bus, are not assumed to be available for feedback. The feedback control achieves transient stabilization and voltage regulation when faults occur to the turbines or the transmission lines, such that parameters (mechanical power and line impedance) may permanently take any (unknown) value. The controller recovers by adaptation the unknown values and simultaneously generates trajectories to be followed by the states, that converge to the new equilibrium point. Copyright © 2004 John Wiley & Sons, Ltd.
Co‐ordinatedH∞control of excitation and governor of hydroturbo‐generator sets: a Hamiltonian approach
Authors: Mei Shengwei , Liu Feng , Chen Ying , Lu Qiang
Published: March 2004

This paper presents a co‐ordinatedH∞controller design of excitation and governor of hydroturbo‐generator sets, which is on the basis of the port‐controlled Hamiltonian (PCH) method. Firstly, the dissipative Hamiltonian realization is achieved via static state feedback, and sequentially the Hamiltonian controller is obtained based on the theory of PCH system with dissipation. Such control strategies fully consider the inherent nonlinearities and non‐minimum phase characteristic of the system dynamics, including the rigid water‐hammer phenomenon. Furthermore, the property of disturbance attenuation of this controller is revealed in the sense ofH∞. The selection of the disturbance attenuation level and the corresponding feedback gain is discussed as well. Then the effects of control input constraints are analysed, sequentially, applied to design the co‐ordinatedH∞saturating control of the considered system. Finally, digital simulations that performed on a one‐machine, infinite‐bus (OMIB) system have verified the effectiveness of the proposed co‐ordinated controllers. Copyright © 2004 John Wiley & Sons, Ltd.
Transient stability improvement through excitation control
Authors: Bazanella A. S. , Conceição C. L.
Published: March 2004

In this paper we present, discuss, extend and compare different design methods for excitation control aiming at improving transient and steady‐state stability. A benchmark with bothLgVand interconnection and damping assignment (IDA) controllers is studied. Furthermore, dynamic extensions for these controllers, that do not require the knowledge of the operating point, are presented. Copyright © 2004 John Wiley & Sons, Ltd.
Accounting for Poisson noise in the multivariate analysis of ToF‐SIMS spectrum images
Authors: Keenan Michael R. , Kotula Paul G.
Published: March 2004

Recent years have seen the introduction of many surface characterization instruments and other spectral imaging systems that are capable of generating data in truly prodigious quantities. The challenge faced by the analyst, then, is to extract the essential chemical information from this overwhelming volume of spectral data. Multivariate statistical techniques such as principal component analysis (PCA) and other forms of factor analysis promise to be among the most important and powerful tools for accomplishing this task. In order to benefit fully from multivariate methods, the nature of the noise specific to each measurement technique must be taken into account. For spectroscopic techniques that rely upon counting particles (photons, electrons, etc.), the observed noise is typically dominated by ‘counting statistics’ and is Poisson in nature. This implies that the absolute uncertainty in any given data point is not constant, rather, it increases with the number of counts represented by that point. Performing PCA, for instance, directly on the raw data leads to less than satisfactory results in such cases. This paper will present a simple method for weighting the data to account for Poisson noise. Using a simple time‐of‐flight secondary ion mass spectrometry spectrum image as an example, it will be demonstrated that PCA, when applied to the weighted data, leads to results that are more interpretable, provide greater noise rejection and are more robust than standard PCA. The weighting presented here is also shown to be an optimal approach to scaling data as a pretreatment prior to multivariate statistical analysis. Published in 2004 by John Wiley & Sons, Ltd.
A more general method for ranking the enrichment of alloying elements in passivation films
Authors: Castle J. E. , Asami K.
Published: March 2004

The corrosion of alloys is often characterized by an enrichment of one or other of the alloying elements within the surface oxide or even within the underlying metallic phase. For some three decades the measurement of such surface enrichment has been one of the most important contributions made by XPS to corrosion science. X‐ray photoelectron spectroscopy permits the composition of the oxide film to be distinguished from that of the metallic surface underlying the oxide so that both can be determined independently. In the mid‐1970s these measurements were crucial in showing that the selective enrichment of chromium in the electrochemical passivation of stainless steel occurred by selective dissolution of iron, and not by selective oxidation of chromium. Measurements of this type are important also in active corrosion, where there is no stable oxide film, as in studies of dealloying phenomena.

The literature now contains numerous cases, many published by one of us (K.A.) based on studies of novel alloys produced in the Institute for Materials Research at Sendai. Typically, measurements are made for a series of binary compositions AxBy ranging from A‐rich to B‐rich alloys, in media that reflect the intended use of the alloy. The results are normally produced in the form of plots of cation composition An+/(An+ + Bm+) against bulk composition A/(A + B) or, in the case of dealloying, as Asurface/(Asurface + Bsurface) against the bulk composition. Although graphical representation is useful in giving the full picture of the alloy's behaviour, it is not so useful in cataloguing or indexing performance.

In this paper we suggest a means to give a rank or performance index as a single number that will characterize the behaviour of the alloy over a wide range of composition for a given medium or exposure condition. The rank number does not imply that any particular mechanism of enrichment is in operation; in various cases of corrosion it might occur by selective precipitation (FeOOH on steels, CuO on cupronickels), by selective dissolution (dezincification of brass) or by preferential incorporation of ions in a passivating oxide or oxyhydroxide (Cr3+ on stainless steels). Although the rank has no mechanistic implications, it is useful within a known class of mechanistic behaviour for indicating the magnitude of the effect and thus for enabling an XPS measurement to be indicative of wanted, or unwanted, behaviour. For example, the rank number could be useful in indicating, perhaps from a single alloy composition, whether a degree of passivation is likely to be achieved for that mix of metallic elements. Copyright © 2004 John Wiley & Sons, Ltd.
Surface analysis of Co–Cr–Mo alloy and Ti substrates silanized with trialkoxysilanes and silane mixtures
Authors: Matinlinna J. P. , Laajalehto K. , Laiho T. , Kangasniemi I. , Lassila L. V. J. , Vallittu P. K.
Published: March 2004

Titanium and cobalt–chromium–molybdenum alloy are widely used inert and biocompatible materials in dentistry and biomedicine. Both materials are non‐degradable and widely relevant in prosthodontics and orthopaedics. The aim of this study was to study the reactions of allyltrimethoxysilane (ALS) and a mixture of allyltrimethoxysilane and 3‐methacryloxypropyltrimethoxysilane (MPS) on Ti and Co–Cr–Mo alloy surfaces. The formation of a uniform, smooth siloxane film, a covalently bonded three‐dimensional Si and O layer, is a prerequisite for the substrate to be bonded with a composite resin. Two silane mixtures of different concentrations were applied onto titanium and Co–Cr–Mo alloy. The silanes were allowed to react with the substrate surface at room temperature and for 1 h at 110 °C. The hypothesis was that a mixture of MPS and ALS could form a uniform, smooth siloxane film on the substrate surface, although ALS is a structurally different trialkoxysilane. Fourier transform infrared spectroscopy, XPS and atomic force microscopy characterization and analysis verified the formation of the siloxane layer on metal substrates, especially on titanium, with silane and silane mixture treatments. Copyright © 2004 John Wiley & Sons, Ltd.
Surface modification of glass and glass fibres by plasma surface treatment
Authors: Lim Kyung‐Bum , Lee Duck‐Chool
Published: March 2004

In this study, glass and glass fibres were treated to dry interfacial treatment by the use of plasma technology. It has been presented that the optimum parameters for the best wettability of the samples at the time of plasma generation were an oxygen atmosphere, 0.1 Torr system pressure, 100 W discharge power and 3 min discharge time. Also, the surface resistance rate and dielectric property were improved. Copyright © 2004 John Wiley & Sons, Ltd.
Using roles in Java
Authors: Schrefl Michael , Thalhammer Thomas
Published: March 2004

Using roles in object‐oriented design leads to a more natural representation of a given problem domain. Despite a lot of research into role–based systems, there is still a gap between conceptual representations of roles and the usage of roles in strongly typed object‐oriented programming languages such as C++ or Java. Since these languages associate classes and their instances exclusively and permanently, representing evolving objects that may take on different roles over time is difficult without special support: (i) entities must be reclassified any time they evolve and (ii) class hierarchies may grow exponentially if entities may take on several independent roles.

This article shows how role hierarchies can be easily implemented in Java. It introduces the Java Role Package, which provides a set of classes to support handling of evolving objects without modifying the semantics of Java itself. Copyright © 2004 John Wiley & Sons, Ltd.
Sex differences in opioid analgesia: clinical and experimental findings
Authors: Fillingim Roger B. , Gear Robert W.
Published: March 2004

Sex differences in analgesic responses to opioids have received increasing attention in recent years. This article examines the literature on sex differences in opioid analgesia, including the results of studies from the authors' own laboratories. In general, nonhuman animal studies suggest more robust opioid analgesic responses in males relative to females; however, the human studies completed to date seem to indicate greater opioid analgesia among females. The most consistent evidence of sex differences in analgesia comes from studies of κ‐agonist‐antagonists administered to patients following oral surgery. These data indicate more robust analgesia in females, and dose‐response characteristics suggest that these agents possess both analgesic and antianalgesic properties, and the agonists may produce these effects in different proportions for women versus men. In contrast, the data from laboratory pain models in humans suggest greater analgesic effects in women in response μ‐opioid agonists but not κ‐agonist‐antagonists. Multiple mechanisms may explain sex differences in opioid analgesia, including gonadal hormonal effects, pharmacokinetics and pharmacodynamics, genetic influences, balance of analgesic/antianalgesic processes, and psychological factors. However, the disparity of results obtained from different pain models—animals versus humans and clinical pain versus experimental pain in humans—suggests that the models themselves are mechanistically different. Additional investigation is warranted in order to further explicate the nature of sex differences in opioid analgesia and to elucidate the underlying mechanisms.
Surgical Options for the Treatment of Hyperthyroidism in the Cat
Authors: Flanders J A
Published: March 2004

Since the first description of feline hyperthyroidism in 1978, numerous treatment options for hyperthyroidism have been reported. Surgical removal of enlarged, autonomously functioning thyroid glands is one of the most commonly used treatment options. Affected cats must have a careful pre-operative evaluation to detect concurrent medical conditions such as renal disease or cardiomyopathy. Since more than 80% of hyperthyroid cats have neoplastic changes in both thyroid glands, bilateral thyroidectomy is necessary for treatment of the majority of hyperthyroid cats. Several different thyroidectomy techniques have been developed in an attempt to minimise potential post-operative complications associated with bilateral thyoidectomy such as hypocalcemia or recurrence of hyperthyroidism. Damage to or removal of all four parathyroid glands during bilateral thyroidectomy causes hypocalcemia, the most common post-operative complication. Recurrence of hyperthyroidism can occur months after initial thyroidectomy if residual adenomatous thyroid tissue is retained in the surgical site. The most effective surgical techniques for bilateral thyroidectomy involve preservation of at least one external parathyroid gland on the surface of the thyroid capsule. Additionally, the majority of the thyroid capsule must be removed to ensure that all neoplastic thyroid tissue is removed. The most recently described feline thyroidectomy techniques involve sequential removal of bilaterally afftected thyroid glands. Staging a bilatcral thyroidectomy allows time for ipsilateral parathyroid tissue to revascularise before the second thyroid gland is removed and the blood supply to the contralateral parathyroid glands is potentially interrupted. Thyroidectomy is a very effective treatment option for hyperthyroid cats. Surgical treatment of hyperthyroidism in cats offers permanent cure without chronic medical management. No specialised equipment other than standard surgical instrumentation and facilities are necessary. With practice, feline thyroidectomy can become a routine procedure in most veterinary hospitals.
Ecological associations between organisms of different evolutionary history: mangrove pneumatophore arthropods as a case study
Authors: Procheş Şerban
Published: March 2004

Typical marine arthropods (crustaceans and halacarid mites), as well as species of recent terrestrial ancestry (insect larvae and mesostigmatid mites) coexist on mangrove pneumatophores. Both groups are affected by desiccation and are less abundant towards the tips of the pneumatophores. The degree of species associations within and between the two groups was investigated. The number of negative associations is higher for marine–marine, as compared to terrestrial–terrestrial and terrestrial–marine species pairs. When environmental stress (as represented by direct sunlight, and elevation on pneumatophores, both resulting in increased desiccation) is considered, associations tend to shift from negative to positive, and this is more obvious in terrestrial–terrestrial species pairs. These results are attributed to the longer co-evolutionary history of the marine species, resulting in a more precise partitioning of the microhabitats, while the relationships between terrestrial species are less stable, and more susceptible to environmental stress.
Immunocompetence and heterozygosity in the mussel Mytilus edulis
Authors: Carissan-Lloyd Florence M.M. , Pipe Richard K. , Beaumont Andy R.
Published: March 2004

Multiple locus allozyme heterozygosity has been shown to be weakly, but significantly correlated with certain fitness parameters in bivalves. Immune function of individual Mytilus edulis from the Menai Strait, Wales, UK was assessed monthly over one year (1997–1998) by measuring total blood cell (haemocyte) counts, differential haemocyte counts (% basophils and eosinophils), phagocytic capability (by zymozan uptake) and intracellular superoxide generation. Sampled mussels were also scored at 9 allozyme loci. Mussels were then grouped into multiple locus heterozygosity (MLH) classes and plotted separately against the different measures of immunocompetence. No significant association was present between MLH and total haemocyte count, phagocytic capability or intracellular superoxide generation. However, there was a significant association between MLH and the character (basophilic or eosinophilic) of circulating haemocytes (r2=0·057, P=0·002). Highly heterozygous individuals tended to have significantly more eosinophilic haemocytes circulating in the blood than highly homozygous individuals. Eosinophilic haemocytes are known to have a high capacity for phagocytosis of invading organisms and these results may therefore be interpreted as increased health (=fitness) in more highly heterozygous individuals.
Age determination, reproduction and growth of the sea urchin Hemicentrotus pulcherrimus in Oshoro Bay, Hokkaido, Japan
Authors: Agatsuma Yukio , Nakata Akifumi
Published: March 2004

The age of the sea urchin Hemicentrotus pulcherrimus in Oshoro Bay at the northern distributional limit of the species was ascertained by counting black bands in charred genital plates after etching. Consequently, the seasonal growth of two year-classes was monitored and the seasonal changes were related to the reproductive cycle and water temperature. A black band at the edge of the genital plates was found in more than 50% of the sea urchins from September to November. No statistical difference of the test diameter and body weight forming the bands between the estimated and actual values showed that the band is formed annually and can be used as a chronometer. The sea urchin grew rapidly for one and a half months, from late August to late September or early October when water temperature reached a maximum of >20°C, then began to fall while the gonads increased in size prior to maturation. Growth ceased during October to November with initiation of gonadal maturation and the peak of black band formation in genital plates. Spawning occurred from March to May, later than in southern Japan. The annual cycle of growth and reproduction of H. pulcherrimus may be flexibly adapted to surbarctic waters.
Somatic energy storage and reproductive investment in the grass goby Zosterisessor ophiocephalus
Authors: Malavasi Stefano , Fiorin Riccardo , Franco Anita , Torricelli Patrizia
Published: March 2004

The pattern of somatic energy storage, measured as body lipid proportion, was investigated in the grass goby Zosterisessor ophiocephalus, by comparing the per cent lipids across three reproductive groups—large males (territory holding, caring for eggs, males), small males (sneaker males) and females—and across a seasonal phase including the entire breeding season and a post-reproductive period. Furthermore, the pattern of some indicators of somatic and reproductive investment, such as gonadosomatic index (GSI) and liversomatic index (LSI), was investigated, as well as the relationship between lipid content and fish body size was studied over time in both sexes. Results showed that the amount of somatic lipids depends largely on the different levels of reproductive investment shown by the breeding individuals. Females had the lowest levels of somatic lipids at the beginning of the breeding season when large males reached, by contrast, the highest levels. Large males showed a strong decrease in their reserves as the breeding season proceeded, and their replenishment was significantly slower than that of smaller males, which had relatively high levels already in September. Analysis of the trends of GSI and LSI revealed that the difference between females and males in the primary reproductive investment (gonadic mass) can explain most of the differences in the levels of somatic energy storage. The relationship between body size and lipid content changed over time, being positive and statistically significant at the beginning of the breeding season for each reproductive group, indicating that during these phases all the breeding individuals had accumulated energy in their tissues and that the breeding season reduced their somatic energy storage although with different intensity.
Ranging and diving behaviour of two ‘offshore’ bottlenose dolphins, Tursiops sp., off eastern Australia
Authors: Corkeron Peter. J. , Martin Anthony R.
Published: March 2004

This paper describes a study of the ranging and diving behaviour of two ‘offshore’ bottlenose dolphins, Tursiops sp., in the waters off south-east Queensland, determined using satellite-linked time-depth recorders attached to two animals. Animal 1's tag transmitted for 30 days, Animal 2's for 143 days. Immediately after tagging, Animal 1 swam south, reaching a point 146 km south of the point of tagging, then swam generally northwards until the tag ceased working. Animal 2's observed range covered 778 km2, with a core area of 86 km2. The greatest north–south distance between all locations for Animal 2 was 43 km. The manner in which maximum dive depth was related to dive duration was analysed using constrained principal curves. These analyses indicated that for both animals, short dives were to less than 5 m, and there was no clear relationship between dives of greater duration and depth. These dolphins appear to behave differently from ‘offshore’ bottlenose dolphins studied elsewhere.
Tag recoveries of the loggerhead sea turtle Caretta caretta in the eastern Adriatic Sea: implications for conservation
Authors: Lazar Bojan , Margaritoulis Dimitris , Tvrtković Nikola
Published: March 2004

Data on tag recoveries of 31 adult female and two juvenile loggerhead turtles (Caretta caretta) along the eastern Adriatic coast were analysed. All adult females originated from Mediterranean nesting areas: 29 from Greece, one from Cyprus and one from Turkey. This is the largest aggregation of long-distance tag recoveries in the Mediterranean for the loggerhead population nesting in Greece. The short period elapsed between the last observation of some turtles on the nesting beach and their recovery suggests the existence of a migratory pathway from the Ionian Sea into the Adriatic. Recoveries of some turtles within a period of a year indicate that loggerheads reside in the Adriatic for some time, suggesting that some individuals may demonstrate a level of site fidelity for these marine habitats. The high concentration of tag returns in the shallow northern Adriatic highlights this region as an important feeding habitat, for the population nesting in Greece in particular. The Ionian–Adriatic loggerheads form an important management sub-unit for this nesting population.
Smooth pursuit deficits in schizophrenia, affective disorder and obsessive–compulsive disorder
Authors: LENCER R. , TRILLENBERG P. , TRILLENBERG-KRECKER K. , JUNGHANNS K. , KORDON A. , BROOCKS A. , HOHAGEN F. , HEIDE W. , AROLT V.
Published: March 2004

Background. In schizophrenia, affective disorders, and obsessive–compulsive disorder (OCD) dysfunction of frontal neuronal circuits has been suggested. Such impairments imply corresponding oculomotor deficits.

Method. Eye movement response to foveofugal and foveopetal step–ramp stimuli was recorded within the same study design in patients with schizophrenia (N=16), affective disorder (N=15), and OCD (N=18) and compared with controls (N=23) using infra-red reflection oculography.

Results. In the foveofugal task steady-state velocity was lower in all patient groups compared with controls. Post-saccadic eye velocity was also decreased in patients with schizophrenia and affective disorder. In the foveopetal stimulus steady-state velocity was reduced in schizophrenic patients, only. Changes of saccadic latencies or position errors were not found in any of the patient groups. Also, pursuit latency was unchanged and initial eye acceleration was not decreased.

Conclusions. Unaltered saccadic parameters indicate intact motion perception in cortical visual area V5. Therefore, the observed deficit of pursuit maintenance implies a dysfunction of frontal networks in all patient groups including the pursuit region of the frontal eye field (FEF). In patients with schizophrenia and affective disorder reduced post-saccadic pursuit initiation may indicate an impaired interaction between the pursuit and the saccadic system.
Schizophrenia and theory of mind
Authors: FRITH C. D.
Published: March 2004

We suspect that people have an everyday theory of mind because they explain and frequently talk about the behaviour of others and themselves in terms of beliefs and desires. Having a theory of mind means that we believe that other people have minds like ours and that we understand the behaviour of these others in terms of the contents of their minds: their knowledge, beliefs and desires. But how can we demonstrate experimentally that people are using their theory of mind to predict the behaviour of others. This problem is particularly acute in the case of animals or young human children when they do not have language. Dennett (1978) discussing Premack & Woodruff's (1978) seminal paper ‘Does the chimpanzee have a theory of mind?’, suggested that the use of false beliefs to explain behaviour would provide convincing evidence. When their belief is true (i.e. corresponds to the actual state of the world) we can explain peoples' behaviour on the basis of the state of the world without needing to know about their beliefs. This ambiguity does not arise when the belief is false. The first experiment to use this approach was published by Wimmer & Perner (1983). They showed that at around 4 years of age a child knows that Maxi will look for his chocolates where Maxi believes them to be, even though the child knows that this belief is false because he has seen Maxi's mother moving the chocolates. In the English-speaking world the task involving Maxi and the chocolates has become the Sally-Anne task (see this issue, Lee et al. 2004).
Curriculum and culture: a model for content selection and teaching approaches in music
Authors: Leung Chi Cheung
Published: March 2004

This paper focuses on the establishment of a curriculum model, as part of a larger study concerning the role of Chinese music in secondary school education in Hong Kong. The study employed a two-pronged approach, consisting of (i) a questionnaire survey conducted among 209 secondary school music teachers, and (ii) interviews with 26 professionals from the cultural sector of Hong Kong. From the results a curriculum model was established which underpins a comprehensive approach to the teaching of Chinese music. This model could further be adapted to address general problems in the selection of curriculum content and teaching approaches.
Peer assessment in musical performance: the development, trial and evaluation of a methodology for the Australian tertiary environment
Authors: Daniel Ryan
Published: March 2004

This article outlines the development and trial of peer assessment procedures for implementation within a music performance context in the Australian tertiary environment. An overview of the literature on peer assessment is presented, followed by reference to specific trials of peer assessment within a tertiary music student context. The paper then presents the rationale for and methodology applied in developing two forms of peer assessment of music performance, for trial across one academic year. Student evaluation data obtained via mid- and end-of-year questionnaires are analysed and discussed, as are implications for further research.
An investigation of young children's timbral sensitivity
Authors: Lowther Dawn
Published: March 2004

This paper reports the development of a discrimination task to investigate the sensitivity of children aged 3–8 years to a range of timbral stimuli. The paper discusses the strengths and weaknesses of other research exploring timbral perception and explains how the findings from these studies shaped the methodological approach of this study. Specifically, it describes how the qualitative data collected gave rise to deeper insights concerning the quantitative data, so questioning the rationale of continuing research in this area through a single quantitative methodological approach.
The effects of sensitivity to criticism on motivation and performance in music students
Authors: Atlas Gordon D. , Taggart Terry , Goodell Debra J.
Published: March 2004

Music education inherently relies on a process of providing and receiving critical feedback. Students who are very sensitive to criticism, however, may present a unique challenge for the music educator. This study investigated the ways in which sensitivity to criticism affects the educational experience of music students. Nineteen students were assessed for sensitivity to criticism, self-reported motivation, and perceived quality of performance early and late in the semester. High scores on the Sensitivity to Criticism Scale (Atlas, 1994) were associated with decreases in ratings of importance of the activity and mildly connected with decreases in enjoyment and confidence levels. Highly sensitive students were more hurt by their instructors’ criticisms, felt they improved less in response to criticism, and found it more difficult to communicate with the instructor following criticism. These results suggest that being sensitive to criticism can have an impact on music students’ motivation and performance – and that instructors should be particularly careful in considering the effects that critical feedback may have on highly sensitive students.
A comprehensive procedure to measure the body dimensions of large African predators with comments on the repeatability of measurements taken from an immobilized African lion (Panthera leo)
Authors: de Waal H. O. , Combrinck W. J. , Borstlap D. G.
Published: March 2004

Specific procedures are described to measure the body dimensions of large African predators; these include measurements of body and tail length, head, canines, mane, limbs, paws and testes. Data on body mass and dimensions were collected from an immobilized sub‐adult male African lion Panthera leo. He was 40 months old and weighed 190 kg. After being immobilized, data on body mass and dimensions were collected by a team comprising a scribe, two operators and assistants. The procedures of measuring the 43 variables on body dimensions were then repeated three times in quick succession, each session lasting about 10 min. The four sessions were handled as if a different individual was measured each time. Except for reports on body mass of lions, there is a paucity of comparable data in the literature for most of the variables presented in this paper. The small dispersion measures of the 43 variables suggest that the specific procedures to measure the body dimensions of a large African predator such as the lion have a high degree of repeatability and can be applied with confidence. The procedure has been used to obtain data on body dimensions of a large number of lions as well as dead specimens of black‐backed jackal Canis mesomelas, caracal Caracal caracal and Cape fox Vulpes chama. The data form part of a database on body dimensions of large African predators created by ALPRU. The objective is to develop non‐invasive techniques to determine whether wild predator populations might have been subjected to abnormal growth and development as a result of negative impacts on their habitat and thus food base.
MHD ballooning instability in the plasma sheet
Authors: Cheng C. Z. , Zaharia S.
Published: March 2004

Based on the ideal MHD model the stability of ballooning modes is investigated by employing realistic 3D magnetospheric equilibria for the substorm growth phase. Our results show that without making compressibility approximations the ballooning modes are unstable for the entire plasma sheet where the equatorial βeq ≥ 1, and the most unstable modes are located in the strong cross‐tail current sheet region in the near‐Earth plasma sheet, which maps to the initial brightening location of the breakup arc in the ionosphere. However, the MHD βeq threshold is too low in comparison with observations by AMPTE/CCE, which show that prior to substorm onset a low frequency instability is excited only when βeq > 50. The difficulty can be mitigated by including kinetic effects, which greatly increase the stabilizing effects of field line tension and can enhance the βeq threshold to limit the unstable region to the cross‐tail current sheet region.