bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceived organizational support and affective commitment: the mediating role of organization‐based self‐esteem in the context of job insecurity
Authors: Lee Jaewon , Peccei Riccardo
Published: December 2006

Research on the relationship between perceived organizational support (POS) and affective organizational commitment (AC) has primarily adopted a social exchange perspective. In this study we considered complementary socio‐emotional explanations of the POS–AC relationship. We focused on the mediating role of organization‐based self‐esteem (OBSE) and tested competing models of the POS–OBSE‐AC relationship separately on data from two Korean banks that experienced different levels of downsizing following the 1997 Korean financial crisis. We further extended the analysis by examining the extent to which the relationship between POS and OBSE and AC, respectively, was affected by employees' perceived sense of job insecurity in the two banks. The results showed that OBSE was a significant mediator of the POS–AC relationship in both organizations. POS, however, also retained a strong independent direct effect on commitment. Moreover, as expected, perceived job insecurity tended to attenuate the POS–OBSE relationship, but augmented the direct relationship between perceived organizational support and affective commitment. Copyright © 2006 John Wiley & Sons, Ltd.
Voltammetric methods for the simultaneous determination of trace metals in foods, plant tissues and soils
Authors: Locatelli Clinio
Published: December 2006

An analytical procedure for the sequential determination of copper(II), chromium(VI), thallium(I), lead(II), tin(II), antimony(III) and zinc(II) by anodic stripping voltammetry (ASV) in three interdependent matrices involved in foods and food chain as meals, cereal plants and soils is described. The digestion of each matrix was carried out using a mixture of concentrated acids: HClHNO3H2SO4 for meals and cereal plants, and HClHNO3 for soils. Dibasic ammonium citrate (0.1 mol L−1; at either pH 6.2 or 8.3) was used as the supporting electrolyte. The voltammetric measurements were carried out using, as working electrode, a stationary hanging mercury drop electrode (HMDE) and a platinum electrode and an Ag|AgCl|KClsat. electrode as auxiliary and reference electrodes, respectively. The analytical procedure was verified by the analyses of the standard reference materials: Wholemeal BCR‐CRM 189, Wheat Flour NIST‐SRM 1567a, Tomato Leaves NIST‐SRM 1573a and Montana Soil Moderately Elevated Traces NIST‐SRM 2711. For all the elements in the certified matrix, the precision as repeatability, expressed as relative standard deviation (sr) was of the order of 3–5%. The accuracy, expressed as relative error (e) was of the order of 3–7%, while the detection limits were in the range 0.011–0103 µg g−1. Once set up on the standard reference materials, the analytical procedure was transferred and applied to commercial meal samples and cereal plants and soil samples taken from sites used for agriculture. A critical comparison with spectroscopic measurements is also discussed. Copyright © 2006 Society of Chemical Industry
Anti‐wear performance of organomolybdenum compounds as lubricant additives
Authors: Feng Xie , Jianqiang Hu , Fazheng Zheng , Feng Ji , Junbing Yao
Published: December 2006

A four‐ball tester was used to evaluate the anti‐wear performance of three kinds of organomolybdemun compounds in engine oils and lithium soap grease, i.e. molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate (MoDTC), and sulphur‐ and phosphorus‐free organomolybdeum (molybdate). The results indicate that a low concentration of MoDDP does not improve the anti‐wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti‐wear properties of the engine oils. MoDTC does not improve the anti‐wear properties of the engine oils, but worsens the anti‐wear properties of the oils. Significant improvement of the anti‐wear properties is obtained with molybdate added in the four fully formulated oils. Both MoDDP and molybdate have good anti‐wear properties in the lithium soap grease, especially MoDDP with a high concentration. Copyright © 2006 John Wiley & Sons, Ltd.
Mass spectrometry for the quantification of bioactive peptides in biological fluids
Authors: Tamvakopoulos Constantin
Published: December 2006

The study of pharmacologically active peptides is central to the understanding of disease and development of novel therapies. It would be advantageous to monitor the fate of bioactive peptides in biological fluids and tissues following theirin vivoadministration (exogenous administration) or the modulation of endogenous factors (e.g., peptide hormones) affected by the administration of a pharmacological agent. Measurement of administered compounds (small molecules) in plasma is a mature field. However, measurement of pharmacologically active peptides presents particular problems for quantitative mass spectrometry, including challenges from selectivity and sensitivity perspectives. Current approaches towards peptide quantification in biological fluids include immunoassays and mass spectrometric techniques. Immunoassays, although sensitive, lack the necessary selectivity for distinction between peptide and metabolites. Modified molecules induced by metabolic transformations (e.g.,N‐ orC‐terminal truncation of the peptide) might not be differentiated by the antibody used in the assay, leading to cross‐reactivity. However, although it is generally accepted that mass spectrometry is an ideal technique for the quantification of trace levels of analytes in biological fluids, immunological techniques are still characterized by better limits of peptide detection. In this review article, novel mass spectrometric approaches and strategies on peptide quantification will be described. The current capabilities and prospects for advances in this critical area of research will be examined. © 2006 Wiley Periodicals, Inc., Mass Spec Rev
Procedure for reliable durability validation of train axles
Authors: Grubisic V. , Fischer G.
Published: December 2006

The structural durability of wheelset axles depends on the operational loading as well as on the fatigue strength of axles. To validate an axle design the time‐varying stresses in individual critical areas of the axle, represented by their stress spectra, must be taken into account. The allowable stresses in individual axle areas depend both on the fatigue strength and on the spectrum of operational stresses. The procedure for the axle structural durability validation, presented in this paper, includes the numerical fatigue life estimation as well as the experimental durability approval. Also the influences of axle design, material properties and manufacturing technology on structural durability are discussed.
Invarianten‐basierte Mehrachsigkeitshypothese zur Anwendung bei Schwingbeanspruchung
Authors: Amstutz H. , Vormwald M. , Olivier R.
Published: December 2006

Die Abschätzung der Lebensdauer bei mehrachsiger Schwingbeanspruchung durch Bezug auf die Wöhlerlinie für reine Zug‐/Druckbeanspruchung führt mit zunehmendem Einfluss einer Schubspannungskomponente häufig zu größeren Abweichungen vom Versuch. Eine deutliche Verbesserung der Vorhersage ist demnach durch Anbindung sowohl an die Wöhlerlinien aus reiner Zug‐/Druckbeanspruchung als auch der aus reiner Schubbeanspruchung zu erwarten.

Auf der Grundlage einer invarianten‐basierten Vergleichsspannung wird in diesem Beitrag eine Hypothese entwickelt, bei der die beiden Grenzfälle exakt erfüllt sind und die für allgemein mehrachsige Beanspruchung zwischen den Grenzfällen interpoliert. Eine empirisch abgestützte Modifikation der Hypothese schließt nichtproportionale Verläufe aus Phasenverschiebung zwischen den Komponenten ein.
Simulation von Schädigungs‐ und Kriechvorgängen im Asphalt
Authors: Herz E. , Vormwald M.
Published: December 2006

In wachsendem Maße besteht Bedarf, nummerische Methoden zur Bemessung von Straßen einzusetzen. Dabei liegt die Hauptschwierigkeit in der Abbildung des hochkomplexen, nichtlinearen Materialverhaltens von Asphalt.

In der vorliegenden Arbeit wird ein kontinuumsmechanisches Materialmodell vorgestellt, das dazu dient, die wesentlichen nichtlinearen mechanischen Prozesse, die in Asphalt ablaufen, zu modellieren. Dazu zählen plastische Verformungen, Schädigung und Rissbildung sowie viskose Prozesse.

Das Modell wird im Rahmen von FEM‐Berechnungen mit dem Programmpaket Abaqus zur Simulation von Asphaltversuchen angewendet.
Quantification of intramyocellular lipids in obese subjects using spectroscopic imaging with high spatial resolution
Authors: Weis J. , Johansson L. , Courivaud F. , Karlsson F.A. , Ahlström H.
Published: December 2006

Quantification of intramyocellular lipids (IMCL) in obese subjects by single‐voxel spectroscopy (SVS) or conventional spectroscopic imaging (SI) often fails due to overlap of IMCL spectral lines by extramyocellular lipids (EMCL), and signal contamination from subcutaneous fat and bone marrow. This study demonstrates that these problems can be solved by high‐resolution SI with 128 phase‐encoding steps and a read gradient during acquisition. The small voxels obtained in this way facilitated differentiation between EMCL and IMCL. This method offers the possibility of studying different muscle groups and the variation of lipids within one muscle. Magn Reson Med 57:22–28, 2007. © 2006 Wiley‐Liss, Inc.
Real‐time gating system for mouse cardiovascular MR imaging
Authors: Sabbah Maher , Alsaid Hasan , Fakri‐Bouchet Latifa , Pasquier Cédric , Briguet André , Canet‐Soulas Emmanuelle , Fokapu Odette
Published: December 2006

Mouse cardiac MR gating using ECG is affected by the hostile MR environment. It requires appropriate signal processing and correct QRS detection, but gating software methods are currently limited. In this study we sought to demonstrate the feasibility of digital real‐time automatically updated gating methods, based on optimizing a signal‐processing technique for different mouse strains. High‐resolution MR images of mouse hearts and aortic arches were acquired using a chain consisting of ECG signal detection, digital signal processing, and gating signal generation modeled using Simulink (The MathWorks, Inc., Natick, MA, USA). The signal‐processing algorithms used were respectively low‐pass filtering, nonlinear passband, and wavelet decomposition. Both updated and nonupdated gating signal generation methods were tested. Noise reduction was assessed by comparison of the ECG signal‐to‐noise ratio (SNR) before and after each processing step. Gating performance was assessed by measuring QRS detection accuracy before and after online trigger‐level adjustments. Low‐pass filtering with trigger‐level adjustment gave the best performance for mouse cardiovascular imaging using gradient‐echo (GE), spin‐echo (SE), and fast SE (FSE) sequences with minimum induced delay and maximum gating efficiency (99% sensitivity and R‐peak detection). This simple digital gating interface will allow various gating strategies to be optimized for cardiovascular MR explorations in mice. Magn Reson Med 57:29–39, 2007. © 2006 Wiley‐Liss, Inc.
Systematic literature review of treatment interventions for upper extremity hemiparesis following stroke
Authors: Urton Marjorie L. , Kohia Mohamed , Davis Janis , Neill Megan R.
Published: December 2006

The primary purpose of this review article is to critically analyse the literature from 1999 to 2005 regarding effective interventions for upper extremity hemiparesis following stroke. The researchers narrowed the scope of the review based on inclusion and exclusion criteria, which yielded 11 pertinent studies congruent with the selection criteria. Studies were categorized using Sackett's levels of evidence, level I being the highest degree of certainty and level V the lowest. Grades of recommendations were then developed, grade A being highly recommended, grade B discretionary and grade C not endorsed. Two studies were endorsed as level I – grade A, six were level II – grade B, and three were level III – grade C. Clinical recommendations inferred from the present evaluation are as follows:

• Electrical stimulation can be used to improve upper limb outcomes in patients with moderate to severe upper limb dysfunction and is feasible for home‐based interventions.

• Therapy that utilizes goal‐directed reaching behaviours promotes more typical reaching patterns than non‐goal‐directed interventions.

• Reach‐to‐grasp movements show greater improvement when compensatory trunk movements are reduced.

• As an addition to regular exercise therapy time, Arm BASIS training may enhance selective movements of the upper extremity (i.e. reaching).

• When performed in conjunction with active neuromuscular stimulation, random and blocked practice may improve pre‐motor, motor and total reaction times of the upper extremity. Copyright © 2006 John Wiley & Sons Ltd.
Evaluation of Daphne genkwa diterpenes: Fingerprint and quantitative analysis by high performance liquid chromatography
Authors: Zhang Shixuan , Zhang Fenghong , Li Xiaona , Dong Weiqun , Wen Luohan , Wang Shisheng
Published: December 2006

Daphne genkwa contains a novel class of anticancer diterpene esters that inhibit DNA topoisomerase I. Fingerprint and quantitative analysis by HPLC were performed in order to characterise and evaluate D. genkwa. A standard fingerprint of Daphne diterpene esters from the root extract was first established by HPLC‐UV, and the major peaks in the fingerprint profile were preliminarily determined using HPLC‐MS. The principal Daphne diterpene esters, yuanhuacine (1), yuanhuadine (2), yuanhuajine (3) and yuanhuagine (4), were isolated and identified using a combination of UV, IR, MS, 1H‐NMR and 13C‐NMR spectral data. Quantitative analysis indicated that 1 was the principal component in the root, and that 2 was the major component in the buds. The average extraction rates of 1 and 2 were 0.0151 and 0.0033% (n = 10) from the root, respectively, and 0.0020 and 0.0078% (n = 3) from the buds, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Nuchal translucency screening: how do women actually utilize the results?
Authors: Caughey Aaron B. , Musci Thomas J. , Belluomini Jenny , Main Denise , Otto Carl , Goldberg James
Published: December 2006

Objective

To examine how women use the nuchal translucency (NT) risk adjustment in decision‐making for invasive prenatal diagnosis.

Study Design

Retrospective cohort study of 1083 consecutive NT screening exams. A screen‐positive test was defined as a risk ≥ 1/300. Primary outcome was what proportion of screen‐positive or screen‐negative women chose to undergo chorionic villus sampling or amniocentesis.

Results

Of the women tested, 79% (858/1083) were ≥ 35‐years‐old and 88% (756/858) of these women had a decrease in age‐related risk after NT. Of the screen‐negative women, 31% (238/756) ≥ 35 years of age chose to have invasive testing as compared to only 11.2% (25/223) of those < 35 years of age (p < 0.001). Of the screen‐positive women, 71% (72/102) ≥ 35 years of age and 100% (2/2) < 35 years of age chose to obtain invasive testing (p = 0.368).

Conclusion

First‐trimester NT screening for Down syndrome (DS) enables a significant number of women over age 35 to lower the risk for DS several fold and avoid the risks of invasive testing. However, despite significant reductions in age‐specific mid‐trimester DS risks, a relatively high proportion of women ≥ 35 years of age still opted for invasive testing. Copyright © 2006 John Wiley & Sons, Ltd.
Computed tomographic reconstruction of a fetus with the dysgnathia complex (agnathia‐otocephaly)
Authors: Rajan Priya V. , Wing Deborah A. , Bocian Maureen , McKeown Anna
Published: December 2006

The dysgnathia complex (agnathia‐otocephaly) (AO) is a lethal malformation that consists of congenital absence of the lower jaw with union or close approximation of the lower ears on the front of the neck, microstomia, and hypoglossia. We present a novel case of agnathia‐otocephaly with associated organomegaly and the use of postmortem 3‐D computed tomographic rendering. Copyright © 2006 John Wiley & Sons, Ltd.
Optimization of phosphopeptide elution conditions in immobilized Fe(III) affinity chromatography
Authors: Imanishi Susumu Y. , Kochin Vitaly , Eriksson John E.
Published: December 2006

While immobilized metal affinity chromatography (IMAC) has been widely used for affinity purification of phosphopeptides, the technique suffers from insufficient specificity. Therefore, there is an urgent need for IMAC optimization to yield the selectivity and sensitivity that is required for more challenging analyses. Recently, 2,5‐dihydroxybenzoic acid (DHB) and phosphoric acid mixture has been reported as an efficient IMAC eluant. The disadvantage of DHB is that is not suitable for electrospray ionization‐mass spectrometry. While further developing the IMAC elution protocol to overcome this problem, we noticed that DHB is not necessary and found a novel combination of phosphoric acid and acetonitrile to be more efficient. The purification efficacy of the novel protocol is superior to all previously described methods, while still being compatible with the most commonly used mass‐spectrometric techniques in phosphoproteomics.
Third‐generation amphiphilic conetworks. I. Synthesis and swelling behavior of poly(N,N‐dimethyl acrylamide)/polydimethylsiloxane conetworks
Authors: Erdodi G. , Kennedy J. P.
Published: December 2006

A strategy has been developed for the synthesis of novel amphiphilic conetworks (APCNs) of poly(N,N‐dimethyl acrylamide) (PDMAAm) and polydimethyl‐siloxane (PDMS) segments crosslinked with polyhydrosiloxanes. The synthesis proceeds in three steps in one pot (see Figure 2 for reactions and abbreviations): (1) the preparation of a charge containing three components (an asymmetric–telechelic macromonomer, MA‐PDMS‐V, plus two symmetric–telechelic crosslinkers, MA‐PDMS‐MA and V‐PDMS‐V), (2) the free‐radical terpolymerization of N,N‐dimethyl acrylamide, MA‐PDMS‐V, and MA‐PDMS‐MA into a slightly crosslinked and soluble graft of a PDMAAm backbone carrying‐PDMS‐V branches, and (3) the crosslinking of PDMS branches with polyhydrosiloxanes. The effects of key experimental parameters (e.g., composition, molecular weights, and initiator and crosslinker concentrations) on synthesis details and swelling behavior have been studied. The water uptake/permeability of APCNs is significantly increased by the addition of homo‐PDMAAm to graft charges, crosslinking of the graft, and, after the desirable morphology is stabilized, removing the homo‐PDMAAm by water extraction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 295–307, 2007
Geometric transitions on non‐Kähler manifolds
Authors: Knauf A.
Published: December 2006

This 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

Social 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

Laos 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

The 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

The 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

We 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

A 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

Gravity 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

Investigations 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

Gravitropism 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

The 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

Methadone 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

The 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

Enterotoxigenic 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

The 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

This 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.
Session Impact and Outcome in Group Psychoeducative Cognitive Behavioural Therapy
Authors: Kellett Stephen , Clarke Suzanne , Matthews Linda
Published: December 2006

The current study investigated the relationship between session impact and outcome in group psychoeducative CBT, conducted in a routine clinical setting. Participants completed a range of outcome measures at screening, start of the group, termination of the group and at the 3-month follow-up of the six-session intervention. At the end of each psychoeducative session, participants completed a group-specific version of the Session Impact Scale. No single psychoeducative session was seen to generate greater impacts than any other session of the six. Clients who experienced a clinically significant reduction in symptoms during the group perceived greater interpersonal impacts in the group. Results suggest that interpersonal aspects such as normalization may be the active ingredient of change in such service delivery settings. The results are discussed in terms of the potential powerful role of non-specific factors in such large groups and directions for further research examining the impact-outcome relationship in group-based CBT.
On the Matching and Proportional Laws of Cybernetic Models
Authors: Young Jamey D. , Ramkrishna Doraiswami
Published: December 2006

The Matching and Proportional Laws are heuristic control policies that have found widespread use in cybernetic models of biological systems. Within this context, the laws serve as optimization surrogates for predicting the response of metabolic control circuits that modulate enzyme levels and activities. The key result of the current contribution is to demonstrate clearly the optimality properties of these laws and the assumptions that underlie their development. In doing so, we arrive at generalized versions of the Matching and Proportional Laws that are shown to collapse to the forms originally derived by Kompala et al. ( Biotechnol. Bioeng. 1986, 28, 1044–1055) when certain simplifications are applied. As a further line of investigation, we show how Kompala et al.apos;s cybernetic laws compare with alternative control policies in their ability to describe diauxic growth behavior of microbial cultures. We find that Kompala et al.apos;s model describes the experimental observations more accurately than other limiting‐case models that are either too aggressive or too passive in capturing the mixed‐substrate growth rates and intermediate lag periods. Monte Carlo analysis of computational growth experiments in which strains obeying different regulatory policies directly compete for available nutrients reveals that the Matching and Proportional Law policy does not maximize the average growth rate of the culture. However, it allocates metabolic resources more frugally than other policies that outperform it and may be more realistic in reflecting the cellapos;s true fitness‐to‐cost tradeoff as judged by its agreement with experimental growth data.
Orbital tuning of a lower Cretaceous composite record (Maiolica Formation, central Italy)
Authors: Sprovieri Mario , Coccioni Rodolfo , Lirer Fabrizio , Pelosi Nicola , Lozar Francesca
Published: December 2006

A high‐resolution pelagic bulk carbonate stable isotope record from a central Tethyan lower Cretaceous composite section is presented. Three well‐exposed sedimentary sequences (Chiaserna Monte Acuto, Bosso, and Gorgo a Cerbara sections, central Italy) cropping out throughout the Maiolica Formation were correlated by a detailed magnetostratigraphy, lithostratigraphy, and calcareous plankton biostratigraphy in order to reconstruct a continuous composite record from the middle Berriasian to the lower Aptian. The integrated stratigraphy of the three sequences provided an accurate time framework for the new high‐resolution C isotope curve which is presented in this study. The composite δ13C signal, recorded in the depth domain, was analyzed by combined Lomb‐Scargle periodogram and weighted wavelet Z transform (WWZ) – weighted wavelet amplitudes (WWA) Foster wavelet spectral methodologies, both appropriate for unevenly sampled curves. These tools allowed us to unravel the main frequencies modulating the record and their hypothetical shift in depth, respectively. The long‐term, ∼400,000 and ∼2,400,000 years, eccentricity cycles were consistently recorded throughout all the composite record. Once band‐pass filtered in these two periodicity bands and compared to the lithologic pattern cycles identified throughout the composite sequence, the δ13C signal was used as a valuable proxy record for a reliable construction of an orbital tuning of the early Cretaceous. An estimated age for all the different stratigraphic events recognized throughout the composite record was reported. In particular, the reestimated ages of the paleomagnetic chrons, documented in the upper part of the record, show differences with those reported by Gradstein et al. (2004) up to ∼2 m.y. The Valanginian carbon shift, present in the middle part of the composite sequence was estimated to be ∼2.3 m.y. long. The good agreement between the estimated age of the base of this positive carbon isotope excursion (∼136.34 m.y.) and the predominant volcanic phase associated to the Paranà‐Etendeka large igneous province intrusion confirmed a possible cause‐effect link between the two events.