bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geometric transitions on non‐Kähler manifolds
Authors: Knauf A. 
Published: December 2006

AbstractThis article is based on the publications [1–3] and the author's PhD‐thesis. We study geometric transitions on the supergravity level using the basic idea of [1], where a pair of non‐Kähler backgrounds was constructed, which are related by a geometric transition. Here we embed this idea into an orientifold setup as suggested in [3]. The non‐Kähler backgrounds we obtain in type IIA are non‐trivially fibered due to their construction from IIB via T‐duality with Neveu–Schwarz flux. We demonstrate that these non‐Kähler manifolds are not half‐flat and show that a symplectic structure exists on them at least locally. We also review the construction of new non‐Kähler backgrounds in type I and heterotic theory as proposed in [2]. They are found by a series of T‐ and S‐duality and can be argued to be related by geometric transitions as well. A local toy model is provided that fulfills the flux equations of motion in IIB and the torsional relation in heterotic theory, and that is consistent with the U‐duality relating both theories. For the heterotic theory we also propose a global solution that fulfills the torsional relation because it is similar to the Maldacena–Nunez background.
Competing interests: Toronto's Chinese immigrant associations and the politics of multiculturalism
Authors: Salaff J. , Chan Pearl 
Published: December 2006

AbstractSocial service agencies and advocacy groups have played an integral role in mediating between the Asian ethnic populations. In the Canadian institutional setting, associations become a means of political expression. Canada incorporates new immigrants into its national institutions. However, these neo‐liberal institutions and policies have not redressed major problems arising in the settlement process. Under Canada's discourse of enlightened multiculturalism, social service agencies are funded to help to integrate diverse peoples. The policy of multiculturalism meshes well with the liberal ideology underlying loose coupling, encouraging people to retain their cultural identities while settling and participating in national processes. These policies are designed to be sensitive to clients' cultural backgrounds; however, there are unforeseen consequences. In this system, different groups are granted different amounts of social, cultural and economic capital along with differential access to this capital, which affects their position and potential for action in other arenas. In particular, we find that the social service approach treats new Chinese immigrants as similar, thereby fostering competition between subgroups over leadership, funds and representation. Our data come from interviews with key figures in the Chinese‐Canadian community and associations, and reviews of press and other media. Copyright © 2006 John Wiley & Sons, Ltd.
Moving lives: migration and livelihoods in the Lao PDR
Authors: Rigg Jonathan 
Published: December 2006

AbstractLaos is one of the poorest and most ‘rural’ countries in the world. Yet there is evidence of heightened levels of mobility as the country is drawn into the wider mainland southeast Asian region. Mobility is becoming increasingly important in supporting and defining livelihoods for some households and villages. The paper reviews the evidence for growing levels of mobility in Laos and, drawing on the experience of the wider region, reflects upon the implications of this for source communities in terms of economy and society. The paper highlights the shifting nature of the meaning of mobility for migrants and, therefore, for villages of origin and those ‘left behind’. The paper proposes that rather than searching out hard‐and‐fast views of migration and its impacts, the focus should be on 14 identified questions or lines of influence. Copyright © 2006 John Wiley & Sons, Ltd.
Crystal structure of the new quaternary copper manganese and zirconium chalcogenides
Authors: Sachanyuk V. P. , Fedorchuk A. O. , Olekseyuk I. D. , Parasyuk O. V. 
Published: December 2006

AbstractThe compounds Cu2MnZrS4 and Cu2MnZrSe4 were obtained by solid‐state synthesis method. It was established using an XRD powder method that they crystallize in the hexagonal structural type (space group P3m1) with unit cell parameters a = 0.37427(2) nm, c = 0.61004(3) nm (Cu2MnZrS4); a = 0.39085(2) nm, c = 0.63709(3) nm (Cu2MnZrSe4). Atomic parameters were calculated using the anisotropic approximation (RI = 0.0523 and RI = 0.0473 for Cu2MnZrS4 and Cu2MnZrSe4, respectively). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lattice dynamics of CuAlO2 under high pressure from ab initio calculations
Authors: Rodríguez‐Hernández P. , Muñoz A. , Pellicer‐Porres J. , Martínez‐García D. , Segura A. , Garro N. , Chervin J. C. , Kim D. 
Published: December 2006

AbstractThe density functional perturbation theory is employed to study the vibrational properties of CuAlO2 under pressure. The calculations are preformed using the pseudopotential wave method and the local density approximation for the exchange‐correlation (XC) potential. The d electrons of Cu are treated as valence states. We present the phonon dispersion curves. Our results are in good agreement with the available experimental Raman scattering experiments. Ab initio calculations show the presence of a dynamical instability, possibly related with the experimentally observed phase transition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural phases of InAs under pressure
Authors: López‐Solano J. , Muñoz A. , Mujica A. 
Published: December 2006

AbstractWe present the results of a theoretical study on the structural stability of InAs under high pressure, with a focus on the pressure regime past the first transition from the low‐pressure zincblende phase to the rocksalt (NaCl‐type) phase. We have examined several candidates proposed for low‐enthalpy phases at higher pressures, among them the super‐Cmcm structure observed in InSb at moderately high pressure and the B10 structure, which is a distortion of the CsCl structure. Our results reproduce the established sequence of transitions and shed further light on the higher pressure regime of this material. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The use of the random positioning machine for the study of gravitational effects on signal transduction in mammalian cells
Authors: Grimm Daniela , Bauer Johann , Infanger Manfred , Cogoli Augusto 
Published: December 2006

AbstractA comprehensive survey is provided on the application of a random positioning machine (RPM) for studies on gravitational effects on mammalian cells. The RPM is suitable to simulate microgravity conditions and allows performing a high number of on‐ground experiments wherein mammalian cells are exposed to reduced gravity. Most of these experiments have been performed either to prove or extend observations made during spaceflights or to develop and prepare new spaceflight experiments. They did not only bring a tremendous number of observations, but they helped to elucidate three dominant cellular pathways that are affected by weightlessness. The apoptotic, the immune‐activating and the bone differentiation pathways are discussed.
Gravity‐sensing and gravity‐related signaling pathways in unicellular model systems of protists and plants
Authors: Hemmersbach Ruth , Braun Markus 
Published: December 2006

AbstractGravity sensing, gravity‐dependent signaling pathways and resulting graviresponses are found even in single cells as shown in studies on unicellular animal and plant model systems. Although the gravity‐dependent responses of single‐celled systems are obviously very different, the presented experimental data from experiments on ground and in space reveal that especially the early phases of gravity sensing share common features. The gravisensory processes can be reduced to two principles: perception via intracellular statoliths and via the whole protoplast. Gravisensory ion channels and cascades of ubiquitous second messengers are proposed in most gravity‐dependent signaling pathways and have been identified in some cases. Cytoskeletal elements have been shown to play a master role in the complex processes of gravity sensing and graviorientation. Research on ground has been complemented with experiments in microgravity, which greatly contributed to our understanding of gravi‐related signaling processes.
From the Bremen Drop Tower to the international space station ISS – Ways to weightlessness in the German space life sciences program
Authors: Ruyters Günter , Friedrich Ulrike 
Published: December 2006

AbstractInvestigations on the effects of gravity on living systems, especially the perception and transduction of this important environmental parameter, are in the focus of the German Space Life Sciences Program since several years. This program is managed – like all other space activities – by the German Aerospace Center DLR in its role as the German Space Agency. Funding of scientists, placing contracts to industry for the development of necessary space research facilities, and providing flight opportunities for performing space experiments including international coordination with other space agencies are the main responsibilities of the agency. In the present contribution the special features of the various flight opportunities, which are made available by DLR for life sciences research, are described in some detail. By this, scientists should become aware of the interesting possibilities to perform space research in the frame of the German Space Life Sciences Program, while other contributions in this special publications will focus on the results obtained, especially in the area of gravity signal transduction.
Interacting signal transduction chains in gravity‐stimulated maize roots
Authors: Hahn Achim , Firn Richard , Edelmann Hans G. 
Published: December 2006

AbstractGravitropism in roots involves at least three signal transduction chains. The first signal transduction chain is sub‐cellular and operates within the gravity‐perceiving cells in the root apex. The output of this perception system feeds into a second intercellular signal transduction chain (widely considered to involve auxin movement) that links events in the apical regions with the third signal transduction chain that controls cell expansion in the elongating cells. The present study probes the disputed role of ethylene in gravitropism by seeking to identify which parts of the gravitropism cascade are influenced by ethylene action. The results suggest that another signal transduction chain, initiated by mechanical impedance to the root apex, interacts with the early stages of the gravitropism cascade and the effects of ethylene on gravitropism could be mediated by the mechanical impedance sensing and response systems.
Can volunteer counsellors help prevent psychological trauma? A preliminary communication on volunteers skill using the ‘Orienting Approach’ to Trauma Counselling
Authors: Phipps Andrew B. , Byrne Mitchell K. , Deane Frank P. 
Published: December 2006

AbstractThe capacity of 73 volunteer telephone counsellors to administer a brief and early intervention for secondary trauma was assessed. The counsellors participated in a 1‐day training programme in the ‘Orienting Approach’ to Trauma Counselling (Phipps & Byrne, 2003). Volunteer counsellors showed significant improvements in both knowledge and skills from pre‐ to post‐training. The potential benefits of this intervention to the community and professional health services are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Differential regional effects of methadone maintenance compared to heroin dependence on μ‐opioid receptor desensitization in rat brain
Authors: Martin Thomas J. , Kahn William R. , Xiao Royu , Childers Steven R. 
Published: December 2006

AbstractMethadone maintenance therapy has been the mainstay of treatment for heroin addiction since the 1970s. Recent studies indicate that methadone is of greater relative intrinsic efficacy than the active metabolites of heroin at μ‐opioid receptors and that the extent of μ‐opioid receptor desensitization is dependent upon agonist efficacy. Regional differences have been found for μ‐opioid receptor desensitization with chronic heroin self‐administration, and a similar paradigm was employed to compare regional differences between the effects of heroin and methadone. Rats were trained to self‐administer heroin i.v., and the dose available was increased incrementally to a terminal value of 6 mg/kg for each infusion. Half of these rats were allowed to continue to self‐administer heroin, while dependence was maintained in the others by hourly infusions of 3 mg/kg of methadone. A separate group of animals was kept on a low dose of heroin. Activation of G‐proteins by the high efficacy agonist DAMGO was decreased to a greater extent in animals treated chronically with methadone compared with those allowed to self‐administer heroin in amygdala, periaqueductal gray, and subicular nucleus. Activation of G‐proteins by the partial agonist endomorphin was decreased in striatum, thalamus, and amygdala in rats from all drug treatment groups, but to a greater extent in the striatum in methadone treated rats compared with the heroin groups. Elucidating the mechanisms by which methadone induces differential desensitization of μ‐opioid receptors across brain regions compared with heroin could provide insights to improve the pharmacotherapy of heroin addiction. Synapse 61:176–184, 2007. © 2006 Wiley‐Liss, Inc.
Outcome of Arthroscopic Repair of Type II SLAP Lesions in Worker's Compensation Patients
Authors: Verma Nikhil N. , Garretson Ralph , Romeo Anthony A. 
Published: December 2006

Purpose Arthroscopic stabilization has become the accepted treatment for type II superior labral anterior and posterior (SLAP) lesions. Short-term results using a variety of techniques were promising, but most reports focus on motivated athletes. The purpose of our report is to evaluate the results of arthroscopic fixation of type II SLAP lesions in 21 patients who suffered a work-related injury and are receiving workers’ compensation. The hypothesis was that in patients with a single event trauma who were receiving workers’ compensation, clinical results would be inferior to those previously reported. Methods Twenty-two consecutive workers’ compensation patients with type II SLAP lesions underwent arthroscopic stabilization between October 1994 and December 1996. All patients received suture anchors with nonabsorbable suture secured around the labrum for definitive fixation. Average age at surgery was 43 and average follow-up time was 27.9 months. Seventeen patients (89%) had an acromioplasty at the time of labral stabilization. Outcome was assessed by analysis of visual analog pain scale, simple shoulder test (SST) and general health status questionnaire (SF-36), subjective patient satisfaction, and ability to return to work. Results Visual analog pain scales improved by an average of 3 points although all patients had significant complaints of pain at follow-up. Simple shoulder test responses showed improvement in 9 out of 12 categories. The SF-36 results showed significant improvements only in the bodily pain category and role: physical category. Five patients required reoperation for persistent pain. However, only seven patients (437%) returned to work at their previous functional level, nine patients (47%) returned to work but at less strenuous jobs, and three patients (16%) did not return to work. Conclusions Currently recommended treatment for type II SLAP lesions is arthroscopic stabilization. When this procedure is performed in workers’ compensation, patients a with single event trauma to the shoulder, objective parameters, and patient self-assessment surveys do show improvement. However, results are inferior to those previously reported in the literature.
Polyarteritis nodosa and cochlear implantation
Authors: Psillas G , Kyriafinis G , Daniilidis J 
Published: December 2006

Polyarteritis nodosa is a systemic disease which affects the small to medium-sized muscular arteries. Sudden or progressive, bilateral hearing loss is a presenting otologic manifestation. To date, no case of cochlear implantation in patients with polyarteritis nodosa has been reported.The authors present a case of polyarteritis nodosa (confirmed by biopsy) in a 71-year-old man with progressive, bilateral sensorineural hearing loss who underwent cochlear implantation. A successful full insertion of the Nucleus 3G electrode array was achieved without surgical or post-operative complications. The patient immediately showed a positive subjective response and, at three month post-operative evaluation, had gained useful open-set speech perception.A review of five temporal bone cases with hearing loss and polyarteritis nodosa revealed the possibility of fibrosis and ossification in the basal turn of the cochlea, of which the surgeon should be aware prior to cochlear implantation.
Prevalence of facial pain in 108 consecutive patients with paranasal mucopurulent discharge at endoscopy
Authors: Clifton N J , Jones N S 
Published: December 2006

We undertook a prospective observational study of 108 consecutive patients with endoscopic paranasal mucopurulent secretions. Only 31 patients (29 per cent) had facial pain. In 20 (65 per cent), the endoscopic site of purulent secretions corresponded to the site of pain. In those with facial pain, 74 per cent had nasal obstruction, 68 per cent had objective hyposmia and 84 per cent had mucopurulent rhinorrhoea. In the 31 patients with facial pain, 19 (61 per cent) became symptom free following medical treatment. The remaining 12 patients underwent surgery and their symptoms resolved, except for one patient with a tension-type headache and another with pain of unknown cause.Most patients with purulent secretions from the paranasal sinuses do not have facial pain; therefore, chronic rhinosinusitis is not synonymous with pain.Patients with sinogenic facial pain usually have endoscopic findings that correlate with the site of pain, and the majority also have other nasal symptoms. Chronic infective rhinosinusitis usually responds to medical therapy, and the remainder resolve with surgery.
Completeness of notification of tuberculosis in The Netherlands: how reliable is record-linkage and capture–recapture analysis?
Authors: van HEST N. A. H. , SMIT F. , BAARS H. W. M. , De VRIES G. , De HAAS P. E. W. , WESTENEND P. J. , NAGELKERKE N. J. D. , RICHARDUS J. H. 
Published: December 2006

SUMMARYThe aim of this study was to describe a systematic process of record-linkage, cross-validation, case-ascertainment and capture–recapture analysis to assess the quality of tuberculosis registers and to estimate the completeness of notification of incident tuberculosis cases in The Netherlands in 1998. After record-linkage and cross-validation 1499 tuberculosis patients were identified, of whom 1298 were notified, resulting in an observed under-notification of 13·4%. After adjustment for possible imperfect record-linkage and remaining false-positive hospital cases observed under-notification was 7·3%. Log-linear capture–recapture analysis initially estimated a total number of 2053 (95% CI 1871–2443) tuberculosis cases, resulting in an estimated under-notification of 36·8%. After adjustment for possible imperfect record-linkage and remaining false-positive hospital cases various capture–recapture models estimated under-notification at 13·6%. One of the reasons for the higher than expected estimated under-notification in a country with a well-organized system of tuberculosis control might be that some tuberculosis cases, e.g. extrapulmonary tuberculosis, are managed by clinicians less familiar with notification of infectious diseases. This study demonstrates the possible impact of violation of assumptions underlying capture–recapture analysis, especially the perfect record-linkage, perfect positive predictive value and absent three-way interaction assumptions.
Classification of temporal profiles of F4+E. colishedding and faecal dry matter in experimental post-weaning diarrhoea of pigs
Authors: GEENEN P. L. , Van der MEULEN J. , BOUMA A. , ENGEL B. , HEESTERBEEK J. A. P. , De JONG M. C. M. 
Published: December 2006

SUMMARYEnterotoxigenic F4+Escherichia colican colonize the intestine of pigs and cause diarrhoea. Our primary goal was to find a discriminant rule to discriminate between F4+E. colishedding profiles as this may reflect differences in the infectiousness of pigs. Our secondary goal was to find a discriminant rule to discriminate between diarrhoeic and non-diarrhoeic pigs. Repeated measurements (bacterial shedding and percentage dry matter of faeces) were taken of 74 weaned pigs that were infected experimentally with F4+E. coli. These measurements were summarized into two new variables by means of a principal components analysis. Discriminant rules were derived based on these summary variables by fitting a mixture of normal distributions. Finally, the association between the classifications (as derived from the discriminant rules) and the occurrence in the pigs of the F4 receptor, an adhesion site for F4+E. coli, was studied. We found that only the classification based on bacterial shedding allowed us to distinguish two significantly different groups of pigs (high and low shedders). Presence of the F4 receptor was associated strongly with pigs being high shedders.
Plague metapopulation dynamics in a natural reservoir: the burrow system as the unit of study
Authors: DAVIS S. , KLASSOVSKIY N. , AGEYEV V. , SULEIMENOV B. , ATSHABAR B. , KLASSOVSKAYA A. , BENNETT M. , LEIRS H. , BEGON M. 
Published: December 2006

SUMMARYThe ecology of plague (Yersinia pestisinfection) in its ancient foci in Central Asia remains poorly understood. We present field data from two sites in Kazakhstan where the great gerbil (Rhombomys opimus) is the major natural host. Family groups inhabit and defend burrow systems spaced throughout the landscape, such that the host population may be considered a metapopulation, with each occupied burrow system a subpopulation. We examine plague transmission within and between family groups and its effect on survival. Transmission of plague occurred disproportionatelywithinfamily groups although not all gerbils became infected once plague entered a burrow system. There were no spatial patterns to suggest that family groups in close proximity to infected burrow systems were more at risk of infection than those far away. At one site, infection increased the chances of burrow-system extinction. Overall, it is useful to consider the burrow system as the unit of study within a much larger metapopulation.
Infectiousness of smallpox relative to disease age: estimates based on transmission network and incubation period
Authors: NISHIURA H. , EICHNER M. 
Published: December 2006

SUMMARYThis study investigated the infectiousness of smallpox relative to the onset of fever using a likelihood-based estimation procedure based on the observed transmission network (n=223) and on the distribution of the incubation period (n=379). Who-infected-whom information enabled us to back-calculate the infectiousness by disease age, employing a step function model for infectiousness. Frequency of secondary transmissions was highest between 3 and 6 days after onset of fever, yielding an expected daily frequency of 20·6% (95% CI 15·1–26·4) of the total number of secondary transmissions, which is consistent with previous observations. The estimated cumulative frequency suggests that 91·1% of secondary transmissions occurred up to 9 days after onset of fever. The proposed method appeared to be useful for diseases with an acute course of illness, where transmission was not hampered by depletion of susceptible contacts.