bluuebunny/crossref_metadata_2025 huggingface dataset:
Laserstrahlschweißen transparenter und farbiger Kunststoffe
Authors: Klein Rolf
Published: September 2007

Das Laserstrahlschweißen thermoplastischer Kunststoffe ist heute ein etabliertes Verfahren in der industriellen Kunststoffbearbeitung. Es hat sich zur vollwertigen Alternative zu konventionellen Fügeverfahren wie Ultraschall‐, Vibrations‐ oder Heißspiegelschweißen bzw. Klebeverfahren entwickelt. Das Laserstrahlschweißen wird dort eingesetzt, wo eine möglichst geringe thermische Belastung der Bauteile bei hoher Schweißnahtqualität erforderlich ist. Weitere Vorteile des Laserstrahlschweißens sind eine erheblich reduzierte Wulstbildung im Vergleich zum Heißspiegelschweißen und die Vermeidung von Partikelemissionen, die beim US‐ oder Vibrationsschweißen auftreten können.
Convexity in x of the level sets of the first Dirichlet eigenfunction
Authors: Chu Chie‐Ping
Published: September 2007

On a planar domain which is convex in x, the level sets of the first Dirichlet eigenfunction for Laplacian are also convex in x. This gives an affirmative answer to a conjecture proposed by B. Kawohl. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strings, dual strings, and related canonical systems
Authors: Kaltenbäck Michael , Winkler Henrik , Woracek Harald
Published: September 2007

A symmetric Nevanlinna function Q is of the form Q (z) = zQs (z2) where Qs and Q 0(z) = zQs (z) are also Nevanlinna functions. In such a situation Qs and –Q–10 are Stieltjes functions. An inverse result of L. de Branges implies that each Nevanlinna function is the Titchmarsh–Weyl coefficient of a uniquely determined canonical system with some nonnegative Hamiltonian matrix function H, and, according to M. G. Krein, each Stieltjes function is the Titchmarsh–Weyl coefficient of a uniquely determined string. The Hamiltonians corresponding to Qs , Q0 and Q are constructed in terms of the string corresponding to Qs and the dual string corresponding to –Q–10. The relations between the associated Fourier transformations are described by commuting isometric isomorphisms between the considered spaces. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A matricial analogue of Fejer's theory for different types of convergence
Authors: Krtinić Đorđe
Published: September 2007

We describe the space of operators on a Hilbert space with the summable Fourier expansion and prove that this space does not depend on the kind of summability method. We consider the same problem in the spaces of operators with respect to unitarily invariant norms. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pointwise convergence of gradient‐like systems
Authors: Lageman Christian
Published: September 2007

S. Łojasiewicz has shown that the ω ‐limit sets of the trajectories of analytic gradient systems consist of at most one point. We extend this result to the larger class of gradient‐like vector fields satisfying an angle condition. In particular, this includes gradient systems, defined by arbitrary C1 functions from an analytic‐geometric category. Corresponding pointwise convergence results are shown for discrete gradient‐like algorithms on a Riemannian manifold. This generalizes recent results by Absil, Mahony, and Andrews to the Riemannian geometry setting. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asymptotic estimations for a p ‐Ginzburg–Landau type minimizer
Authors: Lei Yutian
Published: September 2007

The author establishes the essential estimations, the Lp loc and the Cα estimations of |∇uε |, where uε is the minimizer of a Ginzburg–Landau type functional. Based on the results, the corresponding convergences (when ε → 0) of theminimizer in W1,p and C1,α senses are proved, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An interface problem for a Sierpinski and a Vicsek fractal
Authors: Metz Volker , Grabner Peter
Published: September 2007

We suggest a flexible way to study the self‐similar interface of two different fractals. In contrast to previous methods the participating energies are modified in the neighborhood of the intersection of the fractals. In the example of the Vicsek snowflake and the 3‐gasket, a variant of the Sierpinski gasket, we calculate the admissible transition constants via the “Short‐cut Test”. The resulting range of values is reinterpreted in terms of traces of Lipschitz spaces on the intersection. This allows us to describe the interface effects of different transition constants and indicates the techniques necessary to generalize the present interface results. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Harmonic extensions of distributions
Authors: Alvarez Josefina , Guzmán–Partida Martha , Pérez–Esteva Salvador
Published: September 2007

We obtain harmonic extensions to the upper half space of distributions in the weighted space wn +1D ′, which is the optimal space of tempered distributions S ′‐convolvable with the classical Euclidean version of the Poisson kernel. We also characterize the class of harmonic functions in the upper half space with boundary values in wn +1D ′, extending in this way results of P. Sjögren. Some facts concerning harmonic extensions of distributions in D ′, 1 < p ≤ ∞, are also approached in this paper, as well as natural relations among these spaces and the weighted space wn +1D ′. We can also obtain n ‐harmonic extensions of appropriate weighted integrable distributions associated to a natural product domain version of the Poisson kernel. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Subbundles of symplectic and orthogonal vector bundles over curves
Authors: Hitching George H.
Published: September 2007

We review the notions of symplectic and orthogonal vector bundles over curves, and the connection between principal parts and extensions of vector bundles. We give a criterion for a certain extension of rank 2n to be symplectic or orthogonal. We then describe almost all of its rank n vector subbundles using graphs of sheaf homomorphisms, and give criteria for the isotropy of these subbundles. Finally, we sketch the use of these ideas in moduli questions for symplectic vector bundles. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reconstruction of a large upper tibial wound extending to the knee with a free latissimus dorsi flap: Optimizing the outcomes
Authors: Liau James E. , Pu Lee L. Q.
Published: September 2007

Despite recent advances in free tissue transfer, management of a large upper tibial wound extending to the knee can be challenging for reconstructive surgeons. In this report, we present two cases where a free latissimus dorsi flap was used for successful soft‐tissue coverage of the wound for limb salvage with optimal reconstructive outcomes. Our unique recipient vessel selection allows more effective free‐tissue transfer without using a vein graft. Our preferred flap inset technique with multiple interrupted horizontal mattress sutures over a closed suction drain leads to an improvement of the initial contour of soft‐tissue coverage that may contribute to the final optimized outcome in the lower‐extremity reconstruction with or without a further debulking procedure. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Child support enforcement policy and unmarried fathers' employment in the underground and regular economies
Authors: Rich Lauren M. , Garfinkel Irwin , Gao Qin
Published: September 2007

Some scholars have suggested that a negative consequence of strengthening child support enforcement is to encourage fathers to shift from regular sector to underground employment. We employ data from the Fragile Families and Child Wellbeing Study to investigate the relationship between the strength of child support enforcement (CSE) and levels of underground and regular sector employment among unmarried fathers. We find that, in general, living in a city with stricter CSE is associated with fewer hours of underground employment. We find little evidence that stronger enforcement is associated with employment or hours in the regular sector. © 2007 by the Association for Public Policy Analysis and Management.
Epstein Barr virus induced lymphoma in a child with IPEX syndrome
Authors: Lucas Kenneth G. , Ungar David , Comito Melanie , Groh Brandt
Published: September 2007

IPEX syndrome (immune deficiency, polyendocrinopathy, enteropathy, X‐linked) is a disorder or regulatory T cell (Treg) function which can result in early death due to infection or complications related to autoimmunity. Therapeutic options for these patients can include allogeneic stem cell transplantation (SCT) or the use of immunosuppressive regimens to control the manifestations of autoimmunity. We report a patient with IPEX syndrome who was managed with rapamycin and subsequently developed EBV induced lymphoma. Pediatr Blood Cancer 2008;50:1056–1057. © 2007 Wiley‐Liss, Inc.
Conducting polyaniline composites as microwave absorbers
Authors: John Honey , Thomas Rinku M. , Jacob Joe , Mathew K.T. , Joseph Rani
Published: September 2007

Conducting polymers are excellent microwave absorbers and they show technological advantage when compared with inorganic electromagnetic absorbing materials, being light weight, easily processable, and the ability of changing the electromagnetic properties with nature and amount of dopants, synthesis conditions, etc. In this paper we report the synthesis, dielectric properties, and expected application of conducting composites based on polyaniline (PAN). Cyclohexanone soluble conducting PAN composites of microwave conductivity 12.5 S/m was synthesized by the in situ polymerization of aniline in the presence of emulsion grade polyvinyl chloride. The dielectric properties of the composites, especially the dielectric loss, conductivity, dielectric heating coefficient, absorption coefficient, and penetration depth, were studied using a HP8510 vector network analyzer. The microwave absorption of the composites were studied at different frequency bands i.e, S, C, and X bands (2–12 GHz). The absorption coefficient was found to be higher than 200 m−1 and it can be used for making microwave absorbers in space applications. POLYM. COMPOS., 28:588–592, 2007. © 2007 Society of Plastics Engineers
Effect of rubber hardness on the properties of fiber reinforced plastic composites made by the newly proposed rubber pressure molding technique
Authors: Kar Kamal K. , Sharma S. D. , Kumar Prashant
Published: September 2007

The effect of rubber hardness on the properties of fiber‐reinforced plastic (FRP) composites is investigated in order to know the optimum composition of rubber mold used in rubber pressure molding (RPM) technique. A matching die set was used in RPM method, where the die was made of hard metal like steel and the punch from the flexible rubber like material, natural rubber. The use of flexible rubber punch generates and applies hydrostatic pressure on the surface of FRP composites. The hardness of rubber mold was controlled by incorporating carbon black as a filler material in the matrix of natural rubber and varied from 0 to 75 phr (per hundred rubber) in steps of 15 phr. Burn test, tension test, interlaminar shear test and interlaminar fracture toughness tests were conducted on the FRP composites to measure the void content, presence of delamination, tensile strength, inter laminar shear strength and inter laminar fracture toughness. The results are compared with the FRP composites made by conventional technique to evaluate the performance of RPM technique. It is observed that the laminates produced by RPM technique with different filler content in natural rubber mold show significant improvement in mechanical properties except interlaminar shear strength. POLYM. COMPOS., 28:618–630, 2007. © 2007 Society of Plastics Engineers
Polystyrene/iron phthalocyanine composite: Radiation effect and characterization
Authors: Ghaffar A. M. Abdel , Youssef T.E.
Published: September 2007

PSty/(OR)8PcFe(Pyz)2 composite films were fabricated using cast method. The prepared composite film was investigated as a function of iron phthalocyanine [(OR)8PcFe(Pyz)2] 3 content and applied irradiation dose. The structure of the prepared composite series (I–III) was characterized by using different analytical tools such as Fourier transform infrared, thermogravimetric analysis, and X‐ray diffraction. The modification of the thermal and chemical properties of the prepared composites meet the requirements of advanced technical and industrial applications. POLYM. COMPOS., 28:631–636, 2007. © 2007 Society of Plastics Engineers
Composite electrodes consisting of platinum particles and polyaniline nanowires as electrocatalysts for methanol oxidation
Authors: Liu Feng‐Jiin , Huang Li‐Ming , Wen Ten‐Chin , Yin Kuang‐Chih , Hung Ju‐Shei , Gopalan A.
Published: September 2007

Polyaniline (PANI) with nanowire (PANI‐(NW)) network structure (mean diameter 10–20 nm) was successfully deposited on a stainless steel (SS) electrode by a galvanostatic process. Platinum particles were deposited into the PANI nanowire network structure to result the PANI(NW)‐Pt composite electrode. The PANI(NW)‐Pt electrode was used as electrocatalysts for the electrochemical oxidation of methanol. The PANI nanowires and PANI(NW)‐Pt nanocomposite were characterized by scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and UV–vis absorption spectroscopy. Nanowire morphology with an average diameter of 10–20 nm could be seen from scanning electron micrograph. Small amount (70 mμm) of spherical Pt particles could be deposited into the PANI(NW). Catalytic activity for the oxidation of methanol was studied by using cyclic voltammetry (CV). For comparative purposes, bulk Pt (deposited Pt on SS) and PANI nanowires based electrodes were tested. The PANI(NW)‐Pt nanocomposite electrode exhibited excellent catalytic activity for the electrooxidation of methanol in comparison to bulk Pt electrodes, which reveals that the PANI(NW)‐Pt nanocomposite electrodeis more promising for application in electrocatalyst as a support material. POLYM. COMPOS., 28:650–656, 2007. © 2007 Society of Plastics Engineers
Application of homogenization method on the evaluation and analysis of the effective stiffness for noncontinuous carbon nanotube/polymer composites
Authors: Luo Dongmei , Wang Wen‐Xue , Takao Yoshihiro
Published: September 2007

The effective stiffness of noncontinuous carbon nano‐tubes (CNTs)/polymer composites are predicted by the homogenization method with exact periodic boundary conditions. Numerical calculations for regular and staggered array models are performed by the macro–microscopic finite element methods. The results are compared with those from Mori–Tanaka and Halpin–Tsai theories, which show that the stiffness of CNTs composites are not only related to aspect ratio and CNTs volume fraction as described in the earlier theories, but also sensitive to the space between CNTs ends, the distribution of CNTs within the selected representative volume element, and the geometrical shape of CNTs. The results from the two empirical approaches are included in the present results with special spacing ratios of horizontal and vertical fiber ends (Tf/Hf). It is proved that the homogenization method is an efficient method to predict the effective stiffness of CNTs/polymer composites with periodic microstructure. POLYM. COMPOS., 28:688–695, 2007. © 2007 Society of Plastics Engineers
Adverse reactions of anti‐tuberculosis drugs in hospitalized patients: incidence, severity and risk factors
Authors: Javadi Mohammad Reza , Shalviri Gloria , Gholami Kheirollah , Salamzadeh Jamshid , Maghooli Golshan , Mirsaeedi Seid Mahdi
Published: September 2007

Background

Tuberculosis (TB) has been a common chronic infectious disease in human communities. Besides disease‐related complications, there could be serious adverse reactions due to anti‐tuberculosis (anti‐TB) drug therapy.

Objectives

To assess the incidence and severity of adverse drug reactions (ADRs) induced by anti‐TB drugs. To determine possible covariates associated with detected ADRs.

Methods

All patients with respiratory TB admitted to a teaching hospital who received anti‐TB drugs during the research period entered the study and were monitored for ADRs. Socio‐demographic and medical history of patients were used as independent covariates. The relationship between independent covariates with frequency and severity of ADRs was analysed using multivariate logistic regression. Preliminary analyses of the Mann–Whitney, Chi‐square, Kruskal–Wallis and the Fisher's exact tests were applied to determine factors unlikely associated with the independent variables.

Results

Among 204 patients admitted, there were 92 patients (45.1%) with ADRs induced by anti‐TB drugs. Patients with a previous history of anti‐TB drugs usage (OR = 5.81, 95% confidence interval [95%CI]: 1.31–25.2), patients with a history of drug allergy (OR = 6.68, CI: 1.28–36.2), those from Afghani ethnic (OR = 4.91, 95%CI: 1.28–18.30) as well as smoker patients with concurrent diseases (OR = 19.67, CI: 1.24–341.51) had a higher rate of ADR incidence. Being female (OR = 1.63, 95%CI: 1.96–36.40) and having previous history of ADR (OR = 17.46, 95%CI: 1.96–20.42) were identified as risk factors.

Conclusion

Anti‐TB drugs could cause severe and frequent adverse effects. Females, those with a previous history of ADRs to anti‐TB drugs and Afghani patients, should be considered as high‐risk groups. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and characterization of star polyfluorenes with a C60 core
Authors: Xu Guodong , Han Yang , Sun Minghao , Bo Zhishan , Chen Chunhai
Published: September 2007

C60‐cored star polyfluorenes were synthesized and fully characterized. A high yield (81%) hexakisaddition of C60 was developed by using Prato reaction and bulky fluorene addends. Suzuki polycondensation of the hexakisadducts of C60 carrying six 2‐bromofluorene addends and AB‐type monomer (2‐bromo‐9,9‐dioctylfluorenyl‐4,4,5,5‐tetramethyl‐ [1,3,2]‐dioxaborane) with Pd(PPh3)4 as the catalyst precursor afforded the desired C60‐cored star polyfluorenes. Their three‐dimensional structure can effectively reduce the aggregation of the polyfluorene chains. Annealing studies indicated that the C60‐cored star polyfluorenes are of good color stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4696–4706, 2007
Synthesis and properties of new fluorinated ester, thioester, and amide substituted polythiophenes. Towards superhydrophobic surfaces
Authors: Nicolas Mael , Guittard Frédéric , Géribaldi Serge
Published: September 2007

A series of new fluorinated polythiophenes has been synthesized by oxidative chemical and electrochemical polymerization and by Ullmann coupling. The substitution with the perfluoroalkyl alkyl chain CH2CH2C6F13 on the 3 position of the thiophene ring is performed via an ester, thioester, or amide connector, (CH2)m‐C(O)X, m = 0–2, with a view to investigating the role of the linker on the polymerization and on the properties of the corresponding polymers. The bromination of the monomers at the 2 and 5 positions allows the use of Ullmann coupling to form soluble fluorinated oligomers. The electron affinity was determined from cyclic voltammetry and a value of 3.1 eV was found for the ester derivative; such materials represent interesting candidates for use in light‐emitting devices or as an electron accepting material in photodiodes/solar cells. The oxidative polymerizations need the connector to be spaced out from the heterocycle to reduce its withdrawal effect. The ester, thioester, and amide spacer determined to a large extent the efficiency of the oxidative polymerization, and particularly the electropolymerization, as well as the solubility of the polymers formed. All the polymers were analyzed by GPC and by UV–visible and fluorescence spectroscopies. The electrochemical oxidation of the thioester and amide group prevents the formation of electroactive films by electropolymerization. But in the case of the ester group, the electroformed polymer exhibits exceptional stable superhydrophobic and lipophobic properties because of a porous surface and the presence of a fluorinated chain that confers low surface energy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4707–4719, 2007
Involutions resulting from annual freeze–thaw cycles: a laboratory simulation based on observations in northeastern Japan
Authors: Ogino Yoshiko , Matsuoka Norikazu
Published: September 2007

A pilot laboratory experiment using a reversed two‐layer soil model simulated small‐scale involutions formed in a seasonal frost environment during the last glacial period. At the modelled site, the interface between the upper aeolian sandy loam and the lower volcanic pumice constitutes small‐scale involutions that display upward‐extending tapered projections and downward‐extending round hollows. Two scale‐reduced laboratory models were subjected to three accelerated annual freeze–thaw cycles with monitoring of frost heave, soil temperature, moisture and pressure. Ice segregation near the layer interface induces upheaving of coarse pumice grains on freezing and earlier settlement of mobilised loam on thawing, resulting in deformation of the interface. A reconstructed 3‐D interface displays mounds and depressions with a diameter of 15–20 cm and a height increasing with freeze– thaw alternations. The experimental results imply that the repetition of differential heave and soft‐loam settlement promotes decimetre‐scale involutions in near‐saturated soils subject to deep seasonal frost penetration. Copyright © 2007 John Wiley & Sons, Ltd.
Applying SCORE to field‐based performance evaluations of soldier worn sensor technologies
Authors: Schlenoff Craig , Steves Michelle Potts , Weiss Brian A. , Shneier Mike , Virts Ann
Published: September 2007

Soldiers are often asked to perform missions that last many hours and are extremely stressful. After a mission is complete, the soldiers are typically asked to provide a report describing the most important things that happened during the mission. Due to the various stresses associated with military missions, there are undoubtedly many instances in which important information is missed or not reported and, therefore, not available for use when planning future missions. The ASSIST (Advanced Soldier Sensor Information System and Sensors Technology) program is addressing this challenge by instrumenting soldiers with sensors that they can wear directly on their uniforms. During the mission, the sensors continuously record what is going on around the soldier. With this information, soldiers are able to give more accurate reports without relying solely on their memory. In order for systems like this (often termed autonomous or intelligent systems) to be successful, they must be comprehensively and quantitatively evaluated to ensure that they will function appropriately and as expected in a wartime environment. The primary contribution of this paper is to introduce and define a framework and approach to performance evaluation called SCORE (System, Component, and Operationally Relevant Evaluation) and describe the results of applying it to evaluate the ASSIST technology. As the name implies, SCORE is built around the premise that, in order to get a true picture of how a system performs in the field, it must be evaluated at the component level, the system level, and in operationally relevant environments. The SCORE framework provides proven techniques to aid in the performance evaluation of many types of intelligent systems. To date, SCORE has only been applied to technologies under development (formative evaluation), but the authors believe that this approach would lend itself equally well to the evaluation of technologies ready to be fielded (summative evaluation). © 2007 Wiley Periodicals, Inc.
Two neighboring residues of loop A of the α1subunit point towards the benzodiazepine binding site of GABAAreceptors
Authors: Tan Kelly R. , Baur Roland , Gonthier Anne , Goeldner Maurice , Sigel Erwin
Published: September 2007

Benzodiazepines are widely used drugs exerting sedative, anxiolytic, muscle relaxant, and anticonvulsant effects by acting through specific high affinity binding sites on some GABAAreceptors. It is important to understand how these ligands are positioned in this binding site. We are especially interested here in the conformation of loop A of the α1β2γ2GABAAreceptor containing a key residue for the interaction of benzodiazepines: α1H101. We describe a direct interaction of α1N102 with a diazepam‐ and an imidazobenzodiazepine‐derivative. Our observations help to better understand the conformation of this region of the benzodiazepine pocket in GABAAreceptor.
The hepatic PP1 glycogen‐targeting subunit interaction with phosphorylase a can be blocked by C‐terminal tyrosine deletion or an indole drug
Authors: Kelsall Ian R. , Munro Shonagh , Hallyburton Irene , Treadway Judith L. , Cohen Patricia T.W.
Published: September 2007

The inhibition of hepatic glycogen‐associated protein phosphatase‐1 (PP1‐GL) by glycogen phosphorylase a prevents the dephosphorylation and activation of glycogen synthase, suppressing glycogen synthesis when glycogenolysis is activated. Here, we show that a peptide (280LGPYY284) comprising the last five amino acids of GL retains high‐affinity interaction with phosphorylase a and that the two tyrosines play crucial roles. Tyr284 deletion abolishes binding of phosphorylase a to GL and replacement by phenylalanine is insufficient to restore high‐affinity binding. We show that a phosphorylase inhibitor blocks the interaction of phosphorylase a with the GL C‐terminus, suggesting that the latter interaction could be targeted to develop an anti‐diabetic drug.
Mouse Prickle1 and Prickle2 are expressed in postmitotic neurons and promote neurite outgrowth
Authors: Okuda Hiroaki , Miyata Shingo , Mori Yasutake , Tohyama Masaya
Published: September 2007

The Drosophila planar cell polarity (PCP) gene prickle has been previously indicated as one of the regulators of gastrulation in the early embryonic stage. However, the functional role of prickle in the brain in particular is not known. We first indicated that mouse Prickle1 and Prickle2 are continually expressed in the brain throughout the embryonic stages and are observed to be specifically expressed in the postmitotic neurons. Furthermore, Prickle1 or Prickle2 depletion effectively decreases the neurite outgrowth levels of mouse neuroblastoma Neuro2a cells. These results indicate that mouse Prickle1 and Prickle2 possibly regulate positive neurite formation during brain development.
Professional expertise for radiation therapists in Africa
Authors: Engel-Hills P. C.
Published: September 2007

The radiation therapist (RTT) is a practitioner who must learn to take responsibility as an autonomous professional within a collaborative multi-professional team. A case study of international students on fellowship studies to a South African Higher Education Institution was used as the lens to explore the development of professional expertise in RTTs. Documents and semi-structured interviews generated textual data that was semantically analysed. The findings are presented as a discussion of the themes that emerged from the text data; (1) autonomy in a team, (2) collaboration facilitates learning, (3) the need for professional competence, (4) reflective practice and (5) participatory learning. The paper offers the interpretation of professional competence as a practitioner who has applicable knowledge, clinical and generic competence as well as appropriate behaviour and attitudes. It is proposed that a collaborative, integrated curriculum meets the need for the education of RTTs on the African continent. In such an environment optimised learning is facilitated by access to good clinical role models, the development of skills toward reflective practice and student participation in the learning environment.
Unified PC indices: Relation to isolated magnetic substorms
Authors: Janzhura A. , Troshichev O. , Stauning P.
Published: September 2007

To study the relations of the polar cap magnetic activity (characterized by unified PC indices) to magnetic disturbances in the auroral zone (AE, AL, and AU indices) the average behavior of isolated magnetic disturbances was examined. The statistical analysis of the sudden isolated magnetic substorms, occurring on the background of the quiescent magnetic field, showed that the PC index increases during the hour before the substorm onset, demonstrating the growth phase development. The PC index in the summer polar cap (the summer PC) turned out to be growing much faster than that in the winter polar cap and reached, by the time of the sudden onset, a higher value than the winter PC index, irrespective of the disturbance intensity. After the sudden onset (during the expansion phase) the summer PC index changes little (or even decreases in cases of long powerful substorms), contrary to the winter PC index that changes in conformity with the course of the magnetic substorm. The results give evidence that the summer PC index, being mostly affected by the geoeffective interplanetary electric field, is not responding as strongly to auroral disturbances as the winter PC index, which relies more on the auroral conductivity. The physical meaning of the discrepancy in the behavior of the summer and winter PC indices is discussed.
Future regional Arctic sea ice declines
Authors: Overland James E. , Wang Muyin
Published: September 2007

Because animals and humans respond to seasonally and regionally varying climates, it is instructive to assess how much confidence we can have in regional projections of sea ice from the 20 models provided through the International Panel on Climate Change Fourth Assessment Report (AR4) process (IPCC 2007). Based on the selection of a subset models that closely simulate observed regional ice concentrations for 1979–1999, we find considerable evidence for loss of sea ice area of greater than 40% by 2050 in summer for the marginal seas of the Arctic basin. This conclusion is supported by consistency in the selection of the same models across different regions, and the importance of thinning ice and increased open water at mid‐century to the rate of ice loss. With less confidence, we find that the Bering, Okhotsk and Barents Seas have a similar 40% loss of sea ice area by 2050 in winter. Baffin Bay/Labrador shows little change compared to current conditions. These seasonal ice zones have large interannual/decadal variability in addition to trends. Large model‐to‐model differences were seen for the Kara/Laptev Seas and East Greenland. With a careful evaluation process, AR4 sea ice projections have some utility for use in assessing potential impacts over large Arctic subregions for a 2020–2050 time horizon.
A Fourier‐transform path integral formalism to compute dispersion probability distributions in variable ocean environments
Authors: Alvarez Alberto , Pennel Romain , Garau Bartolomeo , Tintore Joaquin
Published: September 2007

Computing the drift of objects and substances by ocean currents is of high relevance in operational oceanography and environmental managing. This problem is usually solved by a probability distribution computed from an ensemble of simulations of a stochastic differential equation. The accuracy of the results depends on the number of simulations considered in the ensemble. An approach based on a path integral formalism is proposed to compute distribution probabilities. The path integral is solved by a novel algorithm involving Fourier transforms. The best performance of this path integral approach versus traditional matrix multiplication and Monte Carlo techniques is demonstrated by comparing results of probability distributions of dispersion in ocean environments with different spatial scales of variability. Results indicate that the new algorithm provides a probability distribution of dispersion with similar accuracy as that obtained by the Monte Carlo approach, but a hundred times faster.
V arc interplanetary coronal mass ejections observed with the Solar Mass Ejection Imager
Authors: Kahler S. W. , Webb D. F.
Published: September 2007

Since February 2003, the Solar Mass Ejection Imager (SMEI) has been observing interplanetary coronal mass ejections (ICMEs) at solar elongation angles ε > 20°. The ICMEs generally appear as loops or arcs in the sky, but five show distinct outward concave shapes that we call V arcs. We expect to observe some V arcs, formed by trailing edges of ICME flux ropes or by leading ICME edges sheared by solar wind (SW) speed gradients at the heliospheric current sheet. We characterize the properties of these V arcs and compare them with average properties of all SMEI ICMEs. The typical V arc speeds argue against a slow MHD shock interpretation for their structures. We estimate the V arc solar source locations and their opening angle dynamics as tests for SW shearing. The first test contradicts but the second supports the SW shearing explanation. The implications of the small number of V arcs observed with SMEI is considered. The point P approximation used to determine the V arc locations and inferred solar source regions is critically examined in Appendix A.
Intermediate shocks in three‐dimensional magnetohydrodynamic bow‐shock flows with multiple interacting shock fronts
Authors: Cable S. , Lin Y. , Holloway J. L.
Published: September 2007

Previous MHD simulations predict that when switch‐on shock conditions obtain in the solar wind, the bow shock produced in front of an ellipsoidal obstacle will produce a unique bow shock configuration that includes a concave intermediate shock region at the nose of the shock. These simulations have been carried out with hard shell inner boundary conditions. We extend these studies by investigating the configuration of the bow shock when the obstacle is a terrestrial magnetic dipole field. It is found that, in contrast to the typical fast shock, reconnection at the magnetosphere affects the structure of the upstream magnetosheath and bow shock considerably. Asymmetry in magnetic reconnection rates between the northern and southern hemispheres changes the bow shock configuration notably. In the hemisphere where the dipole field is largely antiparallel to the interplanetary magnetic field, the intermediate shock is eliminated in favor of a standard fast shock. In the other hemisphere, however, the intermediate shock still forms as an important, stable element of the overall shock configuration. We also launch a solar wind MHD fast shock into the simulation domain and observe how the resulting waves transmit and reflect in the magnetosheath and magnetosphere and how the general morphology of the bow shock changes.
Transient dynamics of secondary radiation from an HF pumped magnetized space plasma
Authors: Norin L. , Grach S. M. , Thidé B. , Sergeev E. N. , Leyser T. B.
Published: September 2007

In order to systematically analyze the transient wave and radiation processes that are excited when a high‐frequency (HF) radio wave is injected into a magnetized space plasma, we have measured the secondary radiation, or stimulated electromagnetic emission (SEE), from the ionosphere, preconditioned such that geomagnetic field‐aligned plasma irregularities are already present. The transient dynamics experiments were made using a duty cycle of the HF radio wave of 200 ms (180 ms on and 20 ms off) and 100 ms (80 ms on and 20 ms off) for various frequencies near the fifth harmonic of the local ionospheric electron cyclotron frequency. Within the first 10 ms after the radio pulse turn‐on, frequency downshifted structures of the SEE exhibit an overshoot with a maximum at 3 ms < t < 8 ms, whereas the upshifted spectral components do not exhibit this feature. The relative magnitude of the overshoot is strongly dependent on the frequency offset of the pump from the harmonic of the electron cyclotron frequency. A transient blue‐shifted frequency component is identified. This component is upshifted from the pump by 14 kHz < Δ f < 55 kHz and exists only within the first 10 ms after the radio pulse turn‐on. On a longer time scale we analyze the amplitude modulation, or “ringing,” of the reflected radio wave, (also known as “quasi‐periodic oscillations” or “spikes”). The ringing has a frequency of the order 15–20 Hz and we show that this phenomenon is also present in the SEE sidebands and is synchronized with the ringing of the reflected HF wave itself.
A proposed signaling motif for nuclear import in mRNA processing via the formation of arginine claw
Authors: Hamelberg Donald , Shen Tongye , McCammon J. Andrew
Published: September 2007

Phosphorylation of proteins by kinases is the most commonly studied class of posttranslational modification, yet its structural consequences are not well understood. The human SR (serine-arginine) protein ASF/SF2 relies on the processive phosphorylation of the serine residues of eight consecutive arginine-serine (RS) dipeptide repeats at the C terminus by SRPK1 before it can be transported into the nucleus. This SR protein plays critical roles in spliceosome assembly, pre-mRNA splicing, and mRNA export, and the phosphorylation process of the RS repeats has been extensively studied experimentally. However, knowledge of the conformational changes associated with the phosphorylation of this simple sequence and how it triggers the importation of the SR protein is lacking. Here, we have carried out extensive molecular dynamics simulations to show that phosphorylation of the eight RS repeats significantly alters the peptide's conformation and leads to the formation of very stable structures that are likely to be involved in the recognition, binding, and transport of the SR protein. Specifically, we found an unusual symmetry-broken phase of conformations of the repetitive and quasi-symmetric phosphorylated peptide sequence. One of the main characteristics of these conformations is the exposed phosphate groups on the periphery, which possibly could serve as the recognition platform for the transport protein transportin-SR2.
Al
4
H
7
−
is a resilient building block for aluminum hydrogen cluster materials
Authors: Roach P. J. , Reber A. C. , Woodward W. H. , Khanna S. N. , Castleman A. W.
Published: September 2007

The formation and oxygen etching of Al

n

H

m

−
clusters are characterized in a flow reactor experiment with first-principles theoretical investigations to demonstrate the exceptional stability of Al
4
H
7
−
. The origin of the preponderance of Al
4
H
7
−
in the mass spectra of hydrogenated aluminum anions and its resistance to O
2
etching are discussed. Al
4
H
7
−
is shown to have the ability to bond with ionic partners to form stable hydrides through addition of an alkali atom [XAl
4
H
7
(X = Li-Cs)]. An intuitive model that can predict the existence of stable hydrogenated cluster species is proposed. The potential synthetic utility of the superatom assemblies built on these units is addressed.
Die Dialektik in der Metaphysik
Authors: Wöhler Hans-Ulrich
Published: September 2007

In his works on natural philosophy, Walter Burley designed a theory about one particular kind of opposition, namely contrariety. In this respect, one of his most peculiar tractates is the Tractatus primus. However, also in his Physics-commentary, in his Tractatus secundus and in the quaestio Utrum contraria adequata in virtute agant et patiantur ad invicem? one finds arguments revealing a dialectical approach to the problem of the specific identity and/or incompatibility of contrariously opposed qualities. Burley’s rea­­sonings compose an original attempt to use philosophical dialectic not only as a meth­od of disputation, but moreover primarily as a theory of the mediation of opposites. These arguments refer to the scope of natural philosophy, logic, ethics and medicine. An analysis of these arguments and of the criticisms of Thomas Wylton and Konrad of Megenberg reveals Burley’s dialectical approach to be an eminent historical contribution to the solution of fundamental questions within the realm of Aristotelian metaphysics
Lust (delectatio) und Freude (gaudium) bei Thomas von Aquin
Authors: Benz Hubert
Published: September 2007

Thomas Aquinas’s theory of pleasure and joy has many implications of Plato’s thinking, that pleasure must have a certain measure and different degrees, and especially of Aristotle’s teaching about the relationship between pleasure and affection, pleasure and action. Thomas holds pleasure to be given, when a present good is comprehended as attractive, when a soul turns to it and reaches the point of rest in it. Thomas is convicted, that the delectationes intelligibiles are superior to the delectationes sensibiles by reason of their higher union with the intelligible. Looking back to Aristotle Thomas sees the causae delectationis in operation (related to natural love of the self) and in motion. The pleasure of the good person is for Thomas a moral norm of acting: Good is, who has joy to act virtuous. Generally we can speak of a renaissance of pleasure as a category of ethics in the thought of Thomas Aquinas.
Theoretisch glücklich
Authors: van Ackeren Marcel
Published: September 2007

In his Nicomachean Ethics Aristotle gives us two definitions of happiness (eudaimonia): In book I he defines eudaimonia as activity in accordance with the best and most perfect virtue, and very much later in the treatise, in book X, he states that the contemplative life of the philosopher is the most blessed life, and the life of the politician only second in rank. This paper argues that most interpreters have misunderstood the first definition (i.e. they have not correctly identified the best and most perfect virtue) due to the temptation to read the first book with the tenth in mind. A new interpretation of the first definition is corroborated and linked with Aristotle’s statements in book X, so that the entire work seems to be more consistent. Furthermore, a solution to the vexed problem whether moral virtues play a role in the contemplative life is suggested.
Thomas von Aquin und Meister Eckhart
Authors: Winkler Norbert
Published: September 2007

This essay deals with the contrary opinions of Thomas Aquinas and Meister Eckhart on synderesis and conscience. In his theory, Thomas Aquinas focuses more on prudence and less on conscience. Meister Eckhart is the proponent of an attitude ethics focusing on the notion of scintilla animae. For Thomas Aquinas, the Aristotelian thinker, the practical syllogism links judgement to spiritual values, whereas Meister Eckhart gives priority to self-predication. By means of self-predication, action and normativity can be combined immediately; the practical syllogism combines them in an indirect way.
Platon und das Sokratische Pragma
Authors: Meyer Martin F.
Published: September 2007

What made Socrates so special that he became the object of mockery, slander and hate? The answer in the Apology is expressed in the formula of the ‘Socratic pragma’. Plato claims that Socrates’ philosophical enterprise was a reaction to the Delphic oracle according to which no living Greek was wiser than Socrates. But does this really explain what it pretends to explain? The paper argues that this explanation tells us more about Plato’s philosophical approach than about this alleged turning point in Socrates’ life. Our understanding of Socrates’ philosophical development should be based on other Platonic dialogues and the Old Comedy as well, for they inform us about the historical shift of philosophical interest from questions of physics to questions of ethics and political anthropology.
Innovative union driven partnerships with management within the U. S. A.
Authors: Deutsch Steven
Published: September 2007

This is a short report on an innovative private sector, multi-union, labor-management partnership, and on developments in public sector labor-management partnerships within the U. S. A. Broader implications for social partnerships are explored.
Everyday conversations
Authors: Cunliffe Ann L.
Published: September 2007

My position in this paper is that talk is the primary medium of making sense of and constructing our social and organizational realities. In particular, I suggest we need to incorporate the discourse of everyday conversations into critical management theory because it opens up conventional research to new possibilities. Social poetics offers a way of exploring how, in the flow of our embodied dialogical activity, we link ourselves to our surroundings and make sense of our experience. As a form of inquiry, social poetics elevates everyday, imaginative ways of talking; for example, metaphors, storytelling and instructive statements. I explore how the practice of social poetics influences our research, how it may help us understand how managers live their organizational lives, and why it is important to Critical Management Studies. I incorporate extracts from research conversations with managers to illustrate this approach.
Thirty years of work life programmes in Germany
Authors: Fricke Werner
Published: September 2007

Between 1974 and 2002 there were three state financed work life programmes at federal level in Germany, with a financial outlay of more than €1 billion. The author evaluates the programmes’ achievements, conflicts and deficits and pays special attention to the role of social science research in work design projects; he concludes by comparing the German experiences and the Norwegian tradition of work life programmes since the 1960s.

The social partners participated at programme and project level from the very beginning. Many successes have been achieved: the easing of physical work load and unhealthy work; the development of flexible and decentralized work organization in industry and services; providing working people with opportunities to make better use of their qualifications.

There were also lost opportunities: due to massive conflicts between trades unions, employers’ associations and the programme administration, the initial perspective of enhancing democratic participation and enlarging the scope of co-determination in industry was abandoned, after a series of successful experiments, as early as 1980. The implementation of modern forms of work organization, including semi-autonomous group work, largely failed; it was (and still is) restricted to less than 5% of enterprises in Germany. Recent tendencies in industry to return to Tayloristic forms of work organisation, to intensify work processes by introducing market-driven work organisation and flexible working time schemes, directly contradict the original intentions of the programmes.
Action research and the problem of the single case
Authors: Gustavsen Bjørn
Published: September 2007

In his article in Volume 7, No.2 of Concepts and Transformation, Greenwood lays the ground for a self-critical review of action research. This is very much called for but there is a need to avoid this review becoming a revival of yesterday’s “famous cases”. Major parts of today’s action research are oriented towards social movements, learning regions and other levels of organisation far beyond the small group.The associated research challenges can be met only by developing new research platforms and seeking new alliances with other branches of research.
From employee to ‘entreployee’
Authors: Pongratz Hans J. , Voß G. Günter
Published: September 2007

This paper presents the argument that we are witnessing a fundamental transformation in society’s disposition of labor capacity, seen in changes in the labor strategy of large employers. This may be leading to a new type of labor power that could be called ‘self-entrepreneurial’. In the paper’s first part the concept of the ‘entreployee’ (Arbeitskraftunternehmer) is presented briefly, after which, the second part examines several important theoretical objections to the concept, raised in the course of current German debate.