bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability of multielectron bubbles against single‐electron split‐off
Authors: Silvera I. F. , Blanchfield J. , Tempere J. 
Published: April 2003

AbstractRecently, the stability of multielectron bubbles against fissioning into two fragments with large numbers of electrons each was investigated by J. T. Devreese and two of the present authors (I. S. and J. T). In the present work we study a decay mechanism not included in the earlier model on bubble stability: splitting off of single electrons from the multielectron bubble. We find that bubbles with more than a critical number of electrons are stable against this type of decay. The pressure dependence of this critical number was studied. We find that this particular decay mechanism reveals a similar pressure dependence to other decay mechanisms such as shape instabilities in that increasing the pressure destabilizes the bubble whereas a negative pressure increases bubble stability.
A variational method for relativistic computations in atomic and molecular physics
Authors: Dolbeault Jean , Esteban Maria J. , Séré Eric 
Published: April 2003

AbstractThis article is devoted to a two‐spinor characterization of energy levels of Dirac operators based at a theoretical level on a rigorous variational method, with applications in atomic and molecular physics. This provides a numerical method that is free of the numerical drawbacks often present in discretized relativistic approaches. It is moreover independent of the geometry and monotone: Eigenvalues are approximated from above. We illustrate our numerical approach by the computation of the ground state in atomic and diatomic configurations using B‐splines. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 149–155, 2003
Shortcomings in computational chemistry
Authors: Berthier G. , Defranceschi M. , Le Bris C. 
Published: April 2003

AbstractThe purpose of the paper is to point out some weaknesses in computational chemistry. The weaknesses we list arise from issues that are not properly solved and that can either stand on the pure numerical domain or go back to difficulties already present at the modeling stage, or even stem from fundamental open questions in theoretical chemistry itself. To name just a few, the domain decomposition method used in (QM/MM) calculations, the definition of effective core potentials (ECP) or the foundations of various stationary Schrödinger approximations, such as SCF or MCSCF theories or density functional‐type methods are examined. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 156–165, 2003
Adiabatic connection approach to density functional theory of electronic systems
Authors: Savin A. , Colonna F. , Pollet R. 
Published: April 2003

AbstractUsing recent calculations we review some well‐known aspects of density functional theory: the Hohenberg–Kohn theorems, the Kohn–Sham method, the adiabatic connection, and the approximations of local nature. Emphasis is put upon using model Hamiltonians, of which the noninteracting or the physical ones are just particular cases. The model Hamiltonians allow us to produce multireference density functional theory and continuously switch to the physical system. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 166–190, 2003
The issues of size and charge consistency and the implications of translation symmetry in advanced Green's function theories
Authors: Deleuze Michael S. 
Published: April 2003

AbstractThe issues of size consistency and charge consistency in advanced Green's function theories of ionization or electron attachment spectra are thoroughly discussed by adapting the so‐called third‐order algebraic diagrammatic construction scheme [ADC(3)] to the formalism of crystalline orbitals for an extended periodic system. A comparison is made with a number of lower‐order one‐particle Green's function (or one‐electron propagator) schemes, derived using the general algebraic approach in superoperators and binary products. In the canonical picture, one of the implications of size consistency in the dissociation and thermodynamic limits is that a balance must prevail between the number of satellites and the strength of configuration interactions between the main (1h, 1p) and secondary (shake‐up or shake‐on) states in the cation or anion. Charge consistency, or the preservation of the exact particle number upon correlation corrections to the Hartree–Fock ground‐state one‐electron density, is a necessary condition for the correct, i.e., size‐intensive, scaling of static self‐energies and, thus, ionization energies in large inhomogeneous systems. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 191–211, 2003
Recent developments in the contracted Schrödinger equation method: Controlling the N‐representability of the second‐order reduced density matrix
Authors: Valdemoro C. , Alcoba D. R. , Tel L. M. 
Published: April 2003

AbstractIn this article a new procedure aimed at controlling the N‐representability defect of an approximated second‐order reduced density matrix is reported. This procedure should prove to be effective in enhancing the convergence of the iterative solution of the contracted Schrödinger equation besides being of direct applicability in other methods that are reduced density matrices oriented. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 212–222, 2003
Parallel in time algorithms for quantum control: Parareal time discretization scheme
Authors: Maday Yvon , Turinici Gabriel 
Published: April 2003

AbstractThe numerical study of control problems in quantum chemistry requires many computer simulations of the dynamic phenomena involved. These simulations are, in many cases, too expensive to be carried out for complex systems, thus precluding the treatment of interesting practical situations. In a context of fast increasing in both the CPU power available on typical workstations and the number of computers that can be connected through high‐speed networks, the difficulty lies rather in how to obtain “real‐time solutions” than in the amount of CPU power available (which begins to exceed the needs). In this context, the “parareal” time algorithm that parallelizes in the time direction the work required to solve the evolution equations has been introduced in previous works (Lions, J.‐L.; Maday, Y.; Turinici, G. CR Acad Sci Paris I Math 2001, 332(7), 661–668; Bal, G.; Maday, Y. In: Proceedings of the Workshop on Domain Decomposition, LNCSE Series; Springer‐Verlag: Berlin, 2001, 189–202). The theoretical modifications required to apply this algorithm to control problems and more specifically to the problems of quantum control are the main topic of this article. The preliminary results that are presented at the end of the article illustrate the feasibility of the approach and the potential for large time savings. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 223–228, 2003
Determination of enzymatic reaction pathways using QM/MM methods
Authors: Monard Gérald , Prat‐Resina Xavier , González‐Lafont Angels , Lluch José M. 
Published: April 2003

AbstractEnzymes are among the most powerful known catalysts. Understanding the functions of these proteins is one of the central goals of contemporary chemistry and biochemistry. But, because these systems are large they are difficult to handle using standard theoretical chemistry tools. In the last 10 years, we have seen the rapid development of so‐called QM/MM methods that combined quantum chemistry and molecular mechanics to elucidate the structure and functions of systems with many degrees of freedom, including enzymatic systems. In this article, we review the numerical aspects of QM/MM methods applied to enzymes: The energy definition, the special treatment of the covalent QM/MM frontiers, and the exploration of QM/MM potential energy surface. A special emphasis is made on the use of local self‐consistent field and rational function optimization. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 229–244, 2003
Alternative perturbation method for the molecular vibration–rotation problem
Authors: Cassam‐Chenaï P. , Liévin J. 
Published: April 2003

AbstractThis article introduces an alternative perturbation scheme to find approximate solutions of the spectral problem for the rotation–vibration molecular Hamiltonian. The method is implemented for the Watson Hamiltonian and applied to methane. The complete J = 0 spectrum of this penta‐atomic molecule of atmospheric interest is calculated up to 9200 cm−1 in a purely ab initio fashion. Then, the rotational spectra of the vibrational ground state is obtained up to J = 18. The largest relative error is 2.10−5 (for the highest J = 18 level) after scaling of a single parameter. Without scaling the accuracy on the rotational levels is limited by that of the ab initio equilibrium bond distance. The convergence of our results is analyzed with respect to the different parameters involved in our approach. The important concept of vibrational mean‐field configuration interaction is introduced. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 245–264, 2003
Asymmetrical features of mass spectral peaks produced by quadrupole mass filters
Authors: Gibson John Raymond , Taylor Stephen 
Published: April 2003

AbstractThe individual mass spectral peaks produced by a quadrupole mass spectrometer (QMS) are asymmetric; they exhibit a ‘tail’ on the low mass side. In some cases a definite structure is observed in the tail. We show that the tail structure is a consequence of the use of circular electrodes. An extreme case of an experimentally observed QMS mass peak with a distinct tail structure is shown and the general form is reproduced using our numerical model. The effect of instrument resolution, length, operating frequency, ion energy, mass and ion source aperture upon the tail structure are considered. Results show that extensive long tails originate mainly from ions that enter the mass filter at a relatively large distance from the QMS axis; also no significant tail is produced in the case of ideal hyperbolic form electrodes of finite length. Copyright © 2003 John Wiley & Sons, Ltd.
The North Atlantic Oscillation—what role for the Ocean?
Authors: Sutton Rowan T. , Norton Warwick A. , Jewson Stephen P. 
Published: April 2003

AbstractThe extent to which the North Atlantic Oscillation (NAO) is influenced by changes in the ocean state is an issue that has attracted much recent attention. Although there have been counter claims, the weight of evidence clearly suggests that forcing by the ocean of year‐to‐year changes in the NAO is a weak influence by comparison with atmospheric internal variability. The NAO is thus very different in character to the Southern Oscillation (SO), and its predictability—at least on seasonal‐to‐interannual timescales—is almost certainly much lower.Although weak, the influence of the ocean on the NAO is not negligible. In a previous study we found that wintertime North Atlantic climate, including the NAO, was significantly influenced by a tripole pattern of North Atlantic SST anomalies. Here we report the results of experiments to further elucidate the nature of this influence. We show that the tripole pattern induces a significant response both in the tropical Atlantic and at mid‐to‐high latitudes. The low latitude response is forced by the low latitude SST anomalies, but the high latitude response is influenced by the extratropical SST anomalies as well as those in the tropics. Furthermore, we find evidence of nonlinear interaction between the influence of the tropical and extratropical SST anomalies. Lastly, we investigate the feedback from the atmosphere onto the SST tripole. We find that the expected negative feedback is significantly modified at low latitudes by the dynamical response of the atmosphere. Copyright © 2000 Royal Meteorological Society.
The expression of matrix metalloproteinase‐13 and osteocalcin in mouse osteoblasts is related to osteoblastic differentiation and is modulated by 1,25‐dihydroxyvitamin D3 and thyroid hormones
Authors: Fratzl‐Zelman Nadja , Glantschnig Helmut , Rumpler Monika , Nader Alexander , Ellinger Adolf , Varga Franz 
Published: April 2003

AbstractMatrix metalloproteinase‐13 (MMP‐13), is a key protein of bone matrix degradation, and is highly expressed by osteoblasts. We used the osteoblast‐like MC3T3‐E1 cell line and compared the stimulatory effects of the bone resorptive agents 1,25‐dihydroxyvitamin D3 (1,25‐(OH)2D3) 3,3′,5‐triido‐l‐thyronine (T3) on the expression of MMP‐13 mRNA. We showed that the stimulatory effects were time and dose dependent, and were also transduced to the protein level, with 1,25‐(OH)2D3being more potent.MMP‐13 expression in different mouse cells and its localization within developing bone from the onset of osteogenesis were also investigated. 1,25‐(OH)2D3‐ and T3‐regulated osteocalcin (Osc) expression in mouse osteoblasts was compared to hormonal effects on MMP‐13 expression and activity. Here we show divergent and common roles of 1,25‐(OH)2D3and T3 action on the expression of these marker proteins, depending on the stage of cell differentiation. In addition, we propose a role for MMP‐13 in the bone collar of developing long bones. The results could help to more precisely characterize hormonal regulation in the developmental sequence of osteoblasts.
What do patients value in their hospital care? An empirical perspective on autonomy centred bioethics
Authors: Joffe S , Manocchia M , Weeks J C , Cleary P D 
Published: April 2003

Objective:Contemporary ethical accounts of the patient-provider relationship emphasise respect for patient autonomy and shared decision making. We sought to examine the relative influence of involvement in decisions, confidence and trust in providers, and treatment with respect and dignity on patients’ evaluations of their hospital care.Design:Cross-sectional survey.Setting:Fifty one hospitals in Massachusetts.Participants:Stratified random sample of adults (N=27 414) discharged from a medical, surgical, or maternity hospitalisation between January and March, 1998. Twelve thousand six hundred and eighty survey recipients responded.Main outcome measure:Respondent would definitely be willing to recommend the hospital to family and friends.Results:In a logistic regression analysis, treatment with respect and dignity (odds ratio (OR) 3.4, 99% confidence interval (CI) 2.8 to 4.2) and confidence and trust in providers (OR 2.5, CI 2.1 to 3.0) were more strongly associated with willingness to recommend than having enough involvement in decisions (OR 1.4, CI 1.1 to 1.6). Courtesy and availability of staff (OR 2.5, CI 2.1 to 3.1), continuity and transition (OR 1.9, CI 1.5 to 2.2), attention to physical comfort (OR 1.8, CI 1.5 to 2.2), and coordination of care (OR 1.5, CI 1.3 to 1.8) were also significantly associated with willingness to recommend.Conclusions:Confidence and trust in providers and treatment with respect and dignity are more closely associated with patients’ overall evaluations of their hospitals than adequate involvement in decisions. These findings challenge a narrow emphasis on patient autonomy and shared decision making, while arguing for increased attention to trust and respect in ethical models of health care.
Consensus and contention regarding redundant publications in clinical research: cross-sectional survey of editors and authors
Authors: Yank V , Barnes D 
Published: April 2003

Objectives:To examine the perspectives of journal editors and authors on overlapping and redundant publications in clinical research.Design:Pretested cross-sectional survey, containing both forced choice and open ended questions, administered by mail to the senior editors (N=99) and one randomly selected author (N=99) from all journals in theAbridged Index Medicus(1996) that published clinical research.Main measurements:The views of editors and authors about the extent of redundant publications, why they occur, how to prevent and respond to cases, and when the publication of overlapping manuscripts is justified.Results:Seventy two per cent (N=71) of editors and 65% (N=64) of authors completed the survey. There was consensus between both groups that redundant publications occur because authors feel the pressure to publish and journals do not do enough to publicise, criticise, and punish cases, and that the publication of most types of overlapping articles is unacceptable. Sixty seven per cent of authors but only 31% of editors felt, however, that it was justified to publish an overlapping article in a non-peer reviewed symposium supplement, and 68% of editors but 39% of authors supported imposing restrictions on guilty authors’ future submissions. In written comments, 15% to 30% of both groups emphasised that it was justified to publish overlapping articles when there were different or non-English-speaking audiences, new data, strengthened methods, or disputed findings.Conclusions:Editors, authors, and other academic leaders should together develop explicit guidelines that clarify points of contention and ambiguity regarding overlapping manuscripts.
Concern for families and individuals in clinical genetics
Authors: Parker M , Lucassen A 
Published: April 2003

Clinical geneticists are increasingly confronted with ethical tensions between their responsibilities to individual patients and to other family members. This paper considers the ethical implications of a “familial” conception of the clinical genetics role. It argues that dogmatic adherence to either the familial or to the individualistic conception of clinical genetics has the potential to lead to significant harms and to fail to take important obligations seriously.Geneticists are likely to continue to be required to make moral judgments in the resolution of such tensions and may find it useful to have access to ethics training and support.
What exactly is an exact copy? And why it matters when trying to ban human reproductive cloning in Australia
Authors: Gogarty B 
Published: April 2003

This paper examines the current Australian regulatory response to human reproductive cloning. The central consideration is the capacity of the current regulatory regime to effectively deter human cloning efforts. A legislative prohibition on human cloning must be both effective and clear enough to allow researchers to know what practices are acceptable.This paper asks whether the current Australian regime evinces these qualities and suggests that Australia should follow the example set in the UK by the enactment of theHuman Reproductive Cloning Act 2001.
Is there an ethical difference between preimplantation genetic diagnosis and abortion?
Authors: Cameron C , Williamson R 
Published: April 2003

When a person at risk of having a child with a genetic illness or disease wishes to have an unaffected child, this can involve difficult choices. If the pregnancy is established by sexual intercourse, the fetus can be tested early in pregnancy, and if affected a decision can be made to abort in the hope that a future pregnancy with an unaffected fetus ensures. Alternatively, preimplantation genetic diagnosis (PGD) can be used after in vitro fertilisation (IVF) to select and implant an unaffected embryo that hopefully will proceed to term and produce a healthy baby. We are aware that many individuals at risk regard the latter as ethically more acceptable than the former, and examine whether there is an ethical difference between these options. We conclude that PGD and implantation of an unaffected embryo is a more acceptable choice ethically than prenatal diagnosis (PND) followed by abortion for the following reasons:Choice after PGD is seen as ethically neutral because a positive result (“a healthy pregnancy”) balances a negative result (“the destruction of the affected embryo”) simultaneously (assuming the pregnancy proceeds to full term and a healthy baby is born). While there is usually the intention to establish a healthy pregnancy after an abortion, this is not simultaneous;A woman sees abortion as a personal physical violation of her integrity, and as the pregnancy proceeds she increasingly identifies with and gives ethical status to the embryo/fetus as it develops in utero and not in the laboratory;Many people see aborting a fetus as “killing”, whereas in the case of PGD the spare embryos are “allowed to die”. We argue that this difference of opinion gives further weight to our conclusion, but note that this has been addressed and debated at length by others.
Issues of consent and feedback in a genetic epidemiological study of women with breast cancer: Table 1
Authors: Richards M P M , Ponder M , Pharoah P , Everest S , Mackay J 
Published: April 2003

Women (N=21) who had had breast cancer and had been enrolled in a large genetic breast cancer epidemiological study were interviewed about their experience of participation in the study, their attitudes to the confidentiality of data, and the feedback of personal and general research results. Collection of family history information seemed more salient in indicating the genetic nature of the study than the enrolment information sheet. There were no concerns about confidentiality.While participants would have welcomed general feedback about the results of the study and were critical that this had not been provided, the feedback of personal information proved complicated and, sometimes, difficult. It is suggested that individual feedback of genetic test information in epidemiological studies should be undertaken only when there are specific reasons.
Differences in medical students’ attitudes to academic misconduct and reported behaviour across the years—a questionnaire study
Authors: Rennie S C , Rudland J R 
Published: April 2003

Objectives:This study aimed to determine attitudinal and self reported behavioural variations between medical students in different years to scenarios involving academic misconduct.Design:A cross-sectional study where students were given an anonymous questionnaire that asked about their attitudes to 14 scenarios describing a fictitious student engaging in acts of academic misconduct and asked them to report their own potential behaviour.Setting:Dundee Medical School.Participants:Undergraduate medical students from all five years of the course.Method:Questionnaire survey.Main measurements:Differences in medical students’ attitudes to the 14 scenarios and their reported potential behaviour with regards to the scenarios in each of the years.Results:For most of the scenarios there was no significant difference in the response between the years. Significant differences in the responses were found for some of the scenarios across the years, where a larger proportion of year one students regarded the scenario as wrong and would not engage in the behaviour, compared to other years. These scenarios included forging signatures, resubmitting work already completed for another part of the course, and falsifying patient information.Conclusion:Observed differences between the years for some scenarios may reflect a change in students’ attitudes and behaviour as they progress though the course. The results may be influenced by the educational experience of the students, both in terms of the learning environment and assessment methods used. These differences may draw attention to the potential but unintentional pressures placed on medical students to engage in academic misconduct. The importance of developing strategies to engender appropriate attitudes and behaviours at the undergraduate level must be recognised.