bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption Behavior of Asymmetrical Triblock Copolymers at the Solid‐Liquid Interface by Monte Carlo Simulation
Authors: Peng Changjun , Li Jiankang , Liu Honglai , Hu Ying
Published: October 2004

Summary: Monte Carlo simulation on a simple lattice model has been used to study the adsorption of asymmetrical triblock copolymers from a non‐selective solvent at the solid‐liquid interface. The size distributions of train, loop and tail configurations for those copolymers are obtained as well as other details of the adsorption layer microstructure. Also the influence of adsorption energy and the role of molecular symmetry are investigated. A segment‐density profile, the adsorption amount, the surface coverage, and the adsorption layer thickness have been determined. Finally, it is shown that the adsorption behavior of an asymmetrical copolymer can be predicted from the symmetrical copolymer.

Size distributions of the tail configuration for A8−kB20Ak.

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Size distributions of the tail configuration for A8−kB20Ak.
Mean‐Square Radius of Gyration and Degree of Branching of Highly Branched Copolymers Resulting from the Copolymerization of AB2 With AB Monomers
Authors: Zhou Zhiping , Yu Minqiang , Yan Deyue , Li Zeshen
Published: October 2004

Summary: The evolution of the various structural units incorporated into hyperbranched polymers formed from the copolymerization of AB2 and AB monomers has been derived by the kinetic scheme. The degree of branching was calculated with a new definition given in this work. The degree of branching monotonously increased with increasing A group conversion (x) and the maximum value could reach 2r/(1 + r)2, where r is the initial fraction of AB2 monomers in the total. Like the average degree of polymerization, the mean‐square radius of gyration of the hyperbranched polymers increased moderately with A group conversion in the range x < 0.9 and displayed an abrupt rise when the copolymerization neared completion. The characteristic ratio of the mean‐square radius of gyration remained constant for the linear polymers. However, the hyperbranched polymers did not possess this character. In comparison with the linear polymerization, the weight average and z‐average degree of polymerization increased due to the addition of the branched monomer units AB2 and the mean‐square radius of gyration decreased quickly for the products of copolymerization.

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Online‐Messung des Schmierungszustandes mit Hilfe des Übergangswiderstandes
Authors: Deters L. , Bosse H.
Published: October 2004

Heute findet die Begutachtung von aufgetretenen Schmierungszuständen in der Regel erst nach einem Testlauf oder nach einem Schaden statt. Das ist zu spät und liefert keine Hinweise darüber, ob und bis wann der Schmierungszustand gut war oder wann er sich verschlechtert hat. Deshalb ist ein kontinuierlich arbeitendes Online‐Messverfahren wichtig. Vor allem bei Misch‐ und Grenzreibung wird ein kritischer Zustand erst angezeigt, wenn der Schaden bereits eingetreten ist. Das an der Universität Magdeburg entwickelte und in mehreren Forschungsvorhaben eingesetzte Messverfahren auf der Basis der Übergangswiderstandsmessung ermöglicht die Online‐Messung und Identifizierung des Schmierungszustandes im Misch‐ und Grenzreibungsgebiet. Dies wird an Versuchsergebnissen gezeigt, die mit oszillierenden Gleit‐ und Wälzlagern gewonnen wurden.
Wear Aspects During Green Machining of Warm Compacted PM Steels
Authors: Benner A. , Beiss P.
Published: October 2004

The automobile industry is by far the most important end user for structural PM steel parts. Structural PM parts are most frequently used in engines and transmissions. Usually, the PM components are produced by die pressing. The demand for cost reduction and constantly rising quality requirements in this field of application led to the development of new variants of die pressing in the recent past which facilitate the pressing of higher densities and, consequently, higher strengths. One of these new techniques is the warm compaction technology. Apart from improving the materials properties after sintering, this technique offers the advantage that the green compact shows a significantly higher green strength already after the pressing step so that machining can be executed before sintering.

Particularly for high‐strength PM steels, which usually show very uncomfortable machining properties in the as‐sintered condition, a clear cost advantage is attributed to green machining. Initially, it was expected that wear aspects were completely unimportant during green machining and could be neglected to a great extent. However, more detailed investigations prove that in contrast to that assumption a certain wear resistance of the tools is necessary, as well. Taking the example of drilling, this study deals with the wear mechanisms relevant for green machining and with the different wear behaviour of current tool substrates during green machining.
Struktur‐, Härte‐ und Spannungsmessung von ölgeschmierten Metall‐Metall Tribokontakten
Authors: Shakhvorostov D. , Pinto H. , Pyzalla A. , Enders S. , Pöhlmann K. , Scherge M.
Published: October 2004

Mit einem Stift‐Scheibe Tribometer, bei dem eine Graugussscheibe gegen einen verchromten Stahlstift rotiert, wurde kontinuierlich und mit hoher Auflösung Reibung und Verschleiß gemessen. Durch Variation von Normalkraft und Gleitgeschwindigkeit wurden Proben generiert, die sich deutlich in der Höhe der dissipierten Energie unterschieden. Diese Proben wurden vor und nach der tribologischen Belastung strukturell durch eine Feinfokus‐Ionenstrahlanlage (Focused Ion Beam ‐ FIB) untersucht. Es stellte sich heraus, dass im oberflächennahen Bereich durch tribologische Wechselwirkung der Korndurchmesser drastisch abnimmt. Parallel dazu kommt es zum Eintrag von Fremdatomen aus dem Schmierstoff und Umgebung, was durch Augerelektronenspektroskopie nachgewiesen wurde. Mittels Röntgenbeugungsverfahren wurde der mechanische Spannungszustand analysiert, und durch Nanoindentation konnten die mechanischen Eigenschaften im oberflächennahen Bereich bestimmt werden. Tribologisch optimal eingelaufenes Material zeigte im oberflächennahen Bereich nanokristalline Struktur, die erheblich verringerten Reibungswiderstand besaß.
A parallel Galerkin boundary element method for surface radiation and mixed heat transfer calculations in complex 3‐D geometries
Authors: Cui X. , Li B. Q.
Published: October 2004

This paper presents a parallel Galerkin boundary element method for the solution of surface radiation exchange problems and its coupling with the finite element method for mixed mode heat transfer computations in general 3‐D geometries. The computational algorithm for surface radiation calculations is enhanced with the implementation of ideas used for 3‐D computer graphics applications and with data structure management involving creating and updating various element lists optimized for numerical performance. The algorithm for detecting the internal third party blockages of thermal rays is presented, which involves a four‐step procedure, i.e. the primary clip, secondary clip and adaptive integration with checking. Case studies of surface radiation and mixed heat transfer in both simple and complex 3‐D geometric configurations are presented. It is found that a majority of computational time is spent on the detection of foreign element blockages and parallel computing is ideally suited for surface radiation calculations. Results show that the decrease of the CPU time approaches asymptotically to an inverse rule for parallel computing of surface radiation exchanges. For large‐scale computations involving complex 3‐D geometries, an iterative procedure is a preferred approach for the coupling of the Galerkin boundary and finite elements for mixed mode heat transfer calculations. Copyright © 2004 John Wiley & Sons, Ltd.
Volume determination for bulk materials in bunkers
Authors: Ahmed S. A. , Buckingham R. , Gremaud P. A. , Hauck C. D. , Kuster C. M. , Prodanovic M. , Royal T. A. , Silantyev V.
Published: October 2004

A simple model for the determination of the shape of large granular piles in complicated geometries is discussed. An eikonal formulation of the problem is proposed. Two distinct cases arise. In cylindrical geometries, i.e., if both container and possible obstacles have vertical walls, the problem is equivalent to a two‐dimensional travel time problem with obstacles, while in general geometries, this analogy breaks down. In the first case, classical one‐sided discretizations are generalized to handle obstacles without loss in accuracy. In the second case, a fast and efficient numerical method is proposed, implemented and tested. The discrete problems are solved through fast marching. Copyright © 2004 John Wiley & Sons, Ltd.
Common‐refinement‐based data transfer between non‐matching meshes in multiphysics simulations
Authors: Jiao Xiangmin , Heath Michael T.
Published: October 2004

In multiphysics simulations using a partitioned approach, each physics component solves on its own mesh, and the interfaces between these meshes are in general non‐matching. Simulation data (e.g. jump conditions) must be exchanged across the interface meshes between physics components. It is highly desirable for such data transfers to be both numerically accurate and physically conservative. This paper presents accurate, conservative, and efficient data transfer algorithms utilizing a common refinement of two non‐matching surface meshes. Our methods minimize errors in a certain norm while achieving strict conservation. Some traditional methods for data transfer and related problems are also reviewed and compared with our methods. Numerical results demonstrate significant advantages of common‐refinement based methods, especially for repeated transfers. While the comparisons are performed with matching geometries, this paper also addresses additional complexities associated with non‐matching surface meshes and presents some experimental results from 3‐D simulations using our methods. Copyright © 2004 John Wiley & Sons, Ltd.
Parallel global optimization with the particle swarm algorithm
Authors: Schutte J. F. , Reinbolt J. A. , Fregly B. J. , Haftka R. T. , George A. D.
Published: October 2004

Present day engineering optimization problems often impose large computational demands, resulting in long solution times even on a modern high‐end processor. To obtain enhanced computational throughput and global search capability, we detail the coarse‐grained parallelization of an increasingly popular global search method, the particle swarm optimization (PSO) algorithm. Parallel PSO performance was evaluated using two categories of optimization problems possessing multiple local minima—large‐scale analytical test problems with computationally cheap function evaluations and medium‐scale biomechanical system identification problems with computationally expensive function evaluations. For load‐balanced analytical test problems formulated using 128 design variables, speedup was close to ideal and parallel efficiency above 95% for up to 32 nodes on a Beowulf cluster. In contrast, for load‐imbalanced biomechanical system identification problems with 12 design variables, speedup plateaued and parallel efficiency decreased almost linearly with increasing number of nodes. The primary factor affecting parallel performance was the synchronization requirement of the parallel algorithm, which dictated that each iteration must wait for completion of the slowest fitness evaluation. When the analytical problems were solved using a fixed number of swarm iterations, a single population of 128 particles produced a better convergence rate than did multiple independent runs performed using sub‐populations (8 runs with 16 particles, 4 runs with 32 particles, or 2 runs with 64 particles). These results suggest that (1) parallel PSO exhibits excellent parallel performance under load‐balanced conditions, (2) an asynchronous implementation would be valuable for real‐life problems subject to load imbalance, and (3) larger population sizes should be considered when multiple processors are available. Copyright © 2004 John Wiley & Sons, Ltd.
Thermal analysis of 1,4‐di[n′‐(quinolyl)]buta‐1,3‐diynes, structure, and topo‐oligomerization: Polymerization of 3‐ethynylquinoline with the triethyl aluminum/vanadium 2,4‐pentanedionate catalyst system
Authors: Rodríguez J. G. , Lafuente A. , De Los Ríos C.
Published: October 2004

Conjugated 1,4‐bis(n′‐quinolyl)‐1,3‐butadiynes were obtained through the oxidative dimerization of the corresponding n′‐ethynylquinolines catalyzed by cuprous chloride. Differential scanning calorimetry analysis of the 1,4‐bis[n′‐(quinolyl)]buta‐1,3‐diyne molecules produced evidence of a syn–anti rotational equilibrium around the 1,3‐diyne axis and an irreversible transformation into a thermopolymer. The topo‐oligomerization of 1,4‐bis[3′‐(quinolyl)]buta‐1,3‐diyne, which took place by irradiation with sunlight, was investigated with matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Accurate X‐ray molecular structure and refinement analysis of 1,4‐bis[3′‐(quinolyl)]buta‐1,3‐diyne was conducted. The molecular crystalline packing consisted of parallel arrays of two groups of centrosymmetric molecules (antirotamer) in a herringbone assemblage in the solid state. The polymerization of 3‐ethynylquinoline was carried out with the AlEt3/V(acac)3 system to produce a mixture of 1,2,4‐ and 1,3,5‐tris(3′‐quinolyl)benzene cyclotrimers and a trans–cisoid polyene structure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6031–6040, 2004
New results on the influence of the nature of the nucleophile in the stereospecific modification of poly(vinyl chloride)
Authors: Martínez Gerardo , Millán José Luis
Published: October 2004

The nucleophilic substitution reactions on poly(vinyl chloride) (PVC) with potassium 4‐acetamidothiophenolate, potassium 2‐naphthalenethiolate, and sodium 2‐mercaptobenzothiazolate have been undertaken in a cyclohexanone solution. The aim was to study, from a comparative point of view, the influence of nucleophile characteristics, in particular bulkiness, reactivity, and nucleophile polarity, on the reaction mechanisms by following the microstructural evolution with the degree of substitution of the same PVC sample with three types of nucleophile under the same experimental conditions. The quantitative microstructural analysis as a function of conversion has been followed by 13C NMR spectroscopy. Because of the steric hindrance and moderate reactivity of 2‐mercaptobenzothiazolate, the stereoselective nature of the reaction is enhanced, occurring via the meso‐racemic (mr) triad of mmr tetrad, inoperative in practice, unlike the other nucleophiles. This circumstance and the fact that the bulkiness of the nucleophile and interacting effects provide an enhancement of the molecular microstructure‐based mechanisms, such that glass‐transition temperature (Tg) varies with the degree of substitution, in all cases, along with the ratio between the extent to which mmr and rrmr structure intervene in the substitution reaction, thereby providing new and valuable information regarding the Tg–microstructure relationship. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6052–6060, 2004
Molecular mixing of incompatible polymers through formation of and coalescence from their common crystalline cyclodextrin inclusion compounds
Authors: Rusa C. C. , Wei M. , Shuai X. , Bullions T. A. , Wang X. , Rusa M. , Uyar T. , Tonelli A. E.
Published: October 2004

We describe the successful mixing of polymer pairs and triplets that are normally incompatible to form blends that possess molecular‐level homogeneity. This is achieved by the simultaneous formation of crystalline inclusion compounds (ICs) between host cyclodextrins (CDs) and two or more guest polymers, followed by coalescing the included guest polymers from their common CD–ICs to form blends. Several such CD–IC fabricated blends, including both polymer1/polymer2 binary and polymer1/ polymer2/polymer3 ternary blends, are described and examined by means of X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and solid‐state NMR to probe their levels of mixing. It is generally observed that homogeneous blends with a molecular‐level mixing of blend components is achieved, even when the blend components are normally immiscible by the usual solution and melt blending techniques. In addition, when block copolymers composed of inherently immiscible blocks are coalesced from their CD–ICs, significant suppression of their normal phase‐segregated morphologies generally occurs. Preliminary observations of the thermal and temporal stabilities of the CD–IC coalesced blends and block copolymers are reported, and CD–IC fabrication of polymer blends and reorganization of block copolymers are suggested as a potentially novel means to achieve a significant expansion of the range of useful polymer materials. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4207–4224, 2004
Molecular characterization of an improved vector for evaluation of the tumor suppressor versus oncogene abilities of the androgen receptor
Authors: Litvinov Ivan V. , Antony Lizamma , Isaacs John T.
Published: October 2004

Background

There is a growing body of evidence demonstrating that the function of the ligand‐occupied androgen receptor (AR) within the nuclei of normal prostatic epithelial cells acts as a tumor suppressor gene. This is in contrast to the well‐documented ability of the AR within prostate cancer cells to function as an oncogene. Thus, many groups are attempting to understand the biochemistry and signaling cascade differences involved in the switching of AR from a tumor suppressor to an oncogene.

Methods

To do this, of plasmid vectors for transgenic expression of AR are very useful. AR negative PC‐3 human prostate cancer cells were transfected with a plasmid containing the full length coding sequence of AR without its 5′‐ or 3′‐untranslated regions (UTRs) (i.e., pSG5‐AR).

Results

Transgenic expression of the AR protein results in profound growth inhibition which is not relieved by the addition of ligand. A new expression vector for the AR, pAR‐IRES‐EGFP, has been constructed that contains full‐length 5′‐UTR which includes the identified translation regulatory regions, the full length coding sequence and the partial 3′‐UTR, which includes the identified post‐transcriptional regulatory regions. When PC‐3 cells were transfected with the pAR‐IRES‐EGFP vector, it was found that transgenic AR protein expression was not growth inhibitory until ligand was added.

Conclusions

These pSG5‐AR versus pSAR‐IRES‐EGFP clones are being studied to determine the molecular pathways explaining their different response to AR and ligand. © 2004 Wiley‐Liss, Inc.
Enhanced specificity of bacterial spore identification by oxidation and mass spectrometry
Authors: Demirev Plamen A.
Published: October 2004

Addition of an oxidizing agent (e.g., hydrogen peroxide) to intact spores selectively and completely oxidizes Met‐containing biomarker proteins by formation of Met sulfoxides. This reaction increases the masses of the biomarker proteins observed in matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) of Bacillus spores by Δm = (16 × n) Da, where n is the number of Met residues in the sequence of each individual protein. The procedure is very rapid, and can be performed in situ (i.e., on the MALDI target). It confirms the identity of individual biomarkers by comparing the number of Met amino acids from the experimentally determined mass shifts with predictions for n from the tentative amino acid sequence for each protein. In turn, accurate determination of n for several biomarkers allows rapid validation of the initial spore identification by MALDI‐MS. Copyright © 2004 John Wiley & Sons, Ltd.
The analysis of repeated ‘direct’ measures of change illustrated with an application in longitudinal imaging
Authors: Frost Chris , Kenward Michael G. , Fox Nick C.
Published: October 2004

The use of repeated measures of an outcome variable to improve statistical power and precision in randomized clinical trials and cohort studies is well documented. Linear mixed models have great utility in the analysis of such studies in many medical applications including imaging. However, in imaging studies and other applications the basic outcome can be a ‘direct’ measure of change in a variable, as opposed to a difference calculated by subtraction of one measured value from another. The correlation structure of such repeated measures of ‘direct’ change, in particular the non‐independence of within‐person consecutive measures, adds complexity to the analysis. In this paper, we present a family of hierarchical mixed models for the analysis of such data and explain how to implement them using standard statistical software. We illustrate the use of our models with data from a cohort of patients with Alzheimer's disease. Copyright © 2004 John Wiley & Sons, Ltd.
Understanding stress and quality of life for clergy and clergy spouses
Authors: Darling Carol Anderson , Hill E. Wayne , McWey Lenore M.
Published: October 2004

To better understand the stress and quality of life of clergy and clergy spouses, a survey research design was utilized involving a random sample of clergy. Of the 436 respondents involved in this study there were 259 clergy who were employed full‐time and 177 clergy spouses. Various scales related to Family Stress Theory and the ABC‐X model were used in this investigation. Whereas clergy spouses had greater psychological and physiological stress than clergy, clergy had a greater sense of coherence and spiritual resources. Clergy spouses, however had a greater level of coping. Findings indicated that for both clergy and clergy spouses spiritual resources had the greatest total effect on their quality of life. Copyright © 2004 John Wiley & Sons, Ltd.
Efficient Java exception handling in just‐in‐time compilation
Authors: Lee SeungIl , Yang Byung‐Sun , Moon Soo‐Mook
Published: October 2004

Java uses exceptions to provide elegant error handling capabilities during program execution. However, the presence of exception handlers complicates the job of the just‐in‐time (JIT) compiler, while exceptions are rarely used in most programs. This paper describes two techniques for reducing such complications. First, we delay the translation of an exception handler until the exception really occurs. This on‐demand translation of exception handlers allows more optimizations when translating the main flow, without being hindered by constraints caused by the exception flows. Secondly, for those exceptions that are actually thrown during program execution we insert exception‐type check code and a direct branch to the translated exception handlers. This exception handler prediction is motivated by an observation that frequently thrown exceptions are likely to be handled by the same exception handlers, so this will eliminate the exception processing overhead of the Java virtual machine. Our experiments indicate that the code quality of the main flow is no longer affected by the presence of exception handlers. Also, frequently thrown exceptions can be efficiently handled by the exception handler prediction. Copyright © 2004 John Wiley & Sons, Ltd.
Constraint Lingo: towards high‐level constraint programming
Authors: Finkel Raphael , Marek Victor W. , Truszczyński Mirosław
Published: October 2004

Logic programming requires that the programmer convert a problem into a set of constraints based on predicates. Choosing the predicates and introducing appropriate constraints can be intricate and error prone. If the problem domain is structured enough, we can let the programmer express the problem in terms of more abstract, higher‐level constraints. A compiler can then convert the higher‐level program into a logic‐programming formalism. The compiler writer can experiment with alternative low‐level representations of the higher‐level constraints in order to achieve a high‐quality translation. The programmer can then take advantage of both a reduction in complexity and an improvement in runtime speed for all problems within the domain. We apply this analysis to the domain of tabular constraint‐satisfaction problems. Examples of such problems include logic puzzles solvable on a hatch grid and combinatorial problems such as graph coloring and independent sets. The proper abstractions for these problems are rows, columns, entries, and their interactions. We present a higher‐level language, Constraint Lingo, dedicated to problems in this domain. We also describe how we translate programs from Constraint Lingo into lower‐level logic formalisms such as the logic of propositional schemata. These translations require that we choose among competing lower‐level representations in order to produce efficient results. The overall effectiveness of our approach depends on the appropriateness of Constraint Lingo, our ability to translate Constraint Lingo programs into high‐quality representations in logic formalisms, and the efficiency with which logic engines can compute answer sets. We comment on our computational experience with these tools in solving both graph problems and logic puzzles. Copyright © 2004 John Wiley & Sons, Ltd.
Primary Subcutaneous Primitive Neuroectodermal Tumor with Aggressive Behavior and an Unusual Karyotype: Case Report
Authors: Somers Gino R. , Shago Mary , Zielenska Maria , Chan Helen S.L. , Ngan Bo Y.
Published: October 2004

Primitive neuroectodermal tumor/Ewing sarcoma (PNET/ES) rarely occurs in the skin and subcutaneous tissues. We present a case of a 16-year-old girl with primary cutaneous and subcutaneous PNET/ES of the abdominal wall. Despite wide local excision and chemotherapy, she rapidly developed cranial bone and brain metastases, followed by lung and skeletal metastases, and died shortly thereafter. The recurrent tumor exhibited light microscopic features of a small, round, blue cell tumor with intracytoplasmic glycogen. Immunohistochemical analysis showed positivity for CD99, CD56, S100, and glial fibrillary acid protein, and ultrastructural features included cytoplasmic glycogen and focal complex interdigitating synaptic junction-like cytoplasmic folds. Cytogenetic analysis of the relapsed tumor showed a complex karyotype: 47,XX,i(1)(q10), der(4)t(4;19) (q33~q35;q13.1), + 8,t(15;17)(q24;p11.2~p12),der(19)t (19;20)(q13.1;p11.2),der(22)t(20;22)(q13;q13). Cytogenetic, interphase fluorescence in situ hybridization, and molecular genetic analyses failed to show t(11:22) (q24;q12) or abnormalities of chromosome region 22q12. The clinical behavior and atypical and complex cytogenetic abnormalities exhibited by the tumor in this patient are unusual and represent the most aggressive end of the clinical spectrum of cutaneous and subcutaneous PNET/ES.
The influence of social factors on adult sex change and juvenile sexual differentiation in a diandric, protogynous epinepheline, Cephalopholis boenak (Pisces, Serranidae)
Authors: Liu Min , Sadovy Yvonne
Published: October 2004

Adult sex change and juvenile sexual differentiation in the protogynous epinepheline Cephalopholis boenak were demonstrated in captivity to be influenced by social factors. Adult sex change in C. boenak occurred in two directions, female to male and male to female. The presence or absence of a larger male plays an important role in adult female sex change; female(s) did not change sex in the presence of a larger male, but sex change occurred after the removal of the larger males in the same social groups. In male pairs, either the larger or the smaller male changed sex. Male to female sex change has not been reported previously in Cephalopholis, and only rarely in epinephelines. This is the first report of direct male sexual differentiation from juveniles (i.e. primary male development), through manipulating the number of juveniles, in a protogynous epinepheline. All isolated, single, juveniles differentiated directly as males, and male to female sex ratios did not differ significantly from 1:1 in all experimental social groups of two to four juveniles. Differentiating males grew significantly faster than differentiating females and undifferentiated juveniles during the 57‐week experimental period. The role of growth rate in sex determination in C boenak is not known but clearly plays a part in juvenile sexual differentiation and merits further investigation. Social factors influencing bi‐directional adult sex change and juvenile sexual differentiation are a reflection of plasticity of sexual expression in C boenak, in particular, and the Serranidae in general.
Predation by wolves (Canis lupus) on roe deer (Capreolus capreolus) in north‐eastern Apennine, Italy
Authors: Mattioli L. , Capitani C. , Avanzinelli E. , Bertelli I. , Gazzola A. , Apollonio M.
Published: October 2004

Predation by wolves Canis lupus on roe deer Capreolus capreolus was studied by scat analysis in five areas of the Province of Arezzo, north‐eastern Tuscany, Italy. In the intensive study area (ISA) roe deer represented 19.1% of mean per cent volume (MPV) while in the other areas its use ranged between 10.9% and 53.4% of MPV A low degree of variation was found in both annual and seasonal use of roe deer, although seasonal differences were more marked in those areas where roe deer use was lower. In ISA, roe deer was negatively selected among species: the Ivlev's electivity index ranged between – 0.41 and – 0.89. Analysing intra‐specific selection, in ISA < 1‐year‐old individuals were preferred by wolves, mainly during the fawns’ first months of life. This trend was confirmed in the other areas, where fawns represented more than 50% of the relative number of roe deer prey. In ISA, the use of roe deer (as MPV) was not correlated with its density or with that of the main prey, wild boar, and in almost all the other areas no relation between use and density of roe deer was founded. However, in the one area where both roe deer density and use were the highest, these two variables seemed to exhibit a comparable trend. The use of roe deer was negatively correlated with the percentage of forest cover among all the study areas.
Ist Musik die Sprache der Gefühle?
Authors: Willms Harm
Published: October 2004

Zusammenfassung. Befragungen von Patienten, in welchem Umfang Gefühle wie Freude, Trauer, Wut, Angst, Neugier, Überraschung, Verachtung, Mitleid, Ekel, Schuldgefühle und Scham musikalisch ausgedrückt werden können, ergaben keinerlei Unterschiede zwischen dem Ausdruck von Gefühlen in der Improvisationsgruppe und den Gefühlen, die beim Hören von Musik empfunden wurden. Darüber hinaus zeigten die Ergebnisse aber eine sehr signifikante Beschränkung des Gefühlsausdrucks durch Musik auf die Gefühle von Freude, Trauer und Wut. In einem geringen Maße gab es auch einen musikalischen Bezug zu Angst und Überraschung. Bei diesen Gefühlen handelt es sich um diejenigen, die während der symbiotischen Entwicklungsphase, also in der 4. bis 26. Lebenswoche der Entwicklung des Menschen, erscheinen und in dieser Zeit bestimmend sind. Auf diesem Hintergrund werden beispielhaft soziopsychologische Phänomene erklärt wie z.B. die Beeinflussung interpersoneller Beziehungen im Sinne von Nähe und Distanz.
Über die Bedeutung von Musik bei gesunden und psychisch kranken Jugendlichen
Authors: Sauer Karin , Barth Gottfried M. , Klosinski Gunther
Published: October 2004

Zusammenfassung. Es wurde der Frage nachgegangen, wie Jugendliche Musik in unterschiedlichen Situationen und Stimmungen einsetzen und welche Wirkungen dies ihrer Meinung nach hervorbringt. 243 SchülerInnen zwischen 14 und 17 Jahren an Tübinger Haupt-, Real- und Berufsschulen sowie Gymnasien und 25 PatientInnen der Tübinger Kinder- und Jugendpsychiatrie wurden mittels Fragebogen bzw. Interviews befragt. Es wurde angenommen, dass ein Unterschied in der Bedeutung der Musik zwischen “normalen“ und psychisch kranken Jugendlichen bestehe. Diese Hypothese erwies sich jedoch bereits während des Untersuchungsprozesses als falsch. Sowohl “normale“ wie psychiatrisch betreute Jugendliche schätzen die Bedeutung von Musik ähnlich ein; auch ihre auf Musik bezogenen Verhaltensweisen unterscheiden sich unwesentlich. Auf die krankheitsbedingten und individuellen Besonderheiten der PsychiatriepatientInnen wird durch Interviewauszüge speziell Bezug genommen.
Motive im Zeitgenössischen Tanz am Beispiel der Kontaktimprovisation
Authors: Kirschner Werner
Published: October 2004

Zusammenfassung. Kontaktimprovisation zählt zu den bedeutendsten Stilrichtungen des zeitgenössischen Tanzes und hat seit der Entwicklung in den 70er Jahren vornehmlich in den USA und in zahlreichen Ländern Europas Einzug gehalten. Kontaktimprovisation spielt eine unverzichtbare Rolle in der Ausbildung zum/zur professionellen TänzerIn und wird erfolgreich in der Arbeit mit “behinderten Menschen“ (“Danceability“) eingesetzt. Am meisten Verbreitung fand Kontaktimprovisation im pädagogischen Feld der Erwachsenenbildung. Während im Bereich unterschiedlicher Bewegungsangebote der Wissensstand in Bezug auf Motive und Sinnorientierungen sehr ausgeprägt ist, finden wir hinsichtlich verschiedener Tanzstile des zeitgenössischen Tanzes keine empirischen Befunde. Forschungsmethodologisch wird in der vorliegenden Arbeit eine Methodenintegration von qualitativen und quantitativen Verfahren angewendet, die sich an das von Groeben (1986) konzipierte “Zwei-Phasen-Modells“ anlehnt. Neben empirisch fundierten Aussagen über die Motive bzw. die Motivhierarchie der Gesamtgruppe werden geschlechts- und leistungsspezifische Unterschiede herausgearbeitet und mit der allgemeinen Forschungslage verglichen.
Risikoverhalten und unterschiedliche Freizeitengagements Jugendlicher
Authors: Raithel Jürgen
Published: October 2004

Zusammenfassung. Gegenstand des Beitrags ist der Vergleich künstlerisch, musikalisch und sportlich freizeitengagierter Jugendlicher hinsichtlich ihres gesundheitsrelevanten und delinquenten Verhaltens. Datengrundlage bilden Aussagen von 263 Jugendlichen zwischen 13 und 18 Jahren, die anhand eines standardisierten Erhebungsinstruments schriftlich befragt wurden. Ausgehend von unterstellten entwicklungsförderlichen persönlichkeitsstärkenden und sozialen Effekten des Sportengagements, die auch für das musikalische und künstlerische Engagement beansprucht werden, lässt sich anhand der Befunde die günstigste Bilanz zugunsten der jugendlichen “Künstler“ und ein relativ ungünstiges Bild auf Seiten der jugendlichen Sportler feststellen.
“Verzage nicht!“ Zur einzigartigen Gegenwart der Dichtung: Hafez im Iran
Authors: Schurian Walter
Published: October 2004

Zusammenfassung. Die Gedichte des persischen Dichters Hafez stellen nicht nur Ausnahmen im Bereich der Literaturgeschichte dar, sondern sie nehmen auch einen hohen Stellenwert im Leben der Menschen im Iran bis heute ein. So werden sie von vielen gelesen, studiert und sogar bei Entscheidungen und bei Festtagen wie ein Orakel zu Rate gezogen. Dies liegt an mehreren Faktoren wie der geschichtlichen Entwicklung des Lands, der Politik und Religion, aber auch an Faktoren wie Autosuggestion und Glaube. Obwohl direkte Anwendungen auf künstlerische Therapien wie Poesie- und Bibliotherapie kaum gegeben sind, so bedeutet es doch ein erstaunliches Phänomen bis hin zur “Bewältigung“, zur “Autopoiesis“ und zur “Rational-emotiven Therapie“.
Seelische Gesundheit in Ost und West: Analysen auf der Grundlage des Bundesgesundheitssurveys
Authors: Jacobi Frank , Hoyer Jürgen , Wittchen Hans-Ulrich
Published: October 2004

Zusammenfassung. Hintergrund: Bisher vorliegende Studien zur Häufigkeit psychischer Probleme und psychischer Störungen in den alten und neuen Bundesländern zeigen widersprüchliche Befunde: während einige über keine bedeutsamen Unterschiede berichten, haben andere auf eine bedeutsam schlechtere seelische Gesundheitslage in den neuen Bundesländern hingewiesen. Fragestellung: 1. Haben Personen in den neuen Bundesländern häufiger psychische Störungen? 2. Weisen Personen in den neuen Bundesländern eine schlechtere Lebensqualität und geringere Lebenszufriedenheit auf? Methode: Die Ergebnisse beruhen auf einer bevölkerungsrepräsentativen Stichprobe von N = 4181 Personen der erwachsenen Durchschnittsbevölkerung im Alter von 18-65 Jahren (Bundesgesundheitssurvey 1998/99). Psychische Störungen nach DSM-IV wurden mit einem standardisierten diagnostischen Interview (M-CIDI), die gesundheitsbezogene Lebensqualität mit dem SF-36 beurteilt. Ergebnisse: Die 12-Monatsprävalenz psychischer Störungen beträgt 28% (neue Bundesländer), bzw. 32% (alte Bundesländer); das Lebenszeitrisiko beträgt 38,5% gegenüber 44%. Auch nach Kontrolle soziodemographischer und körperlicher Morbiditätsvariablen bestätigt sich insgesamt sowie für die Einzeldiagnosen die tendenziell höhere Morbiditätsrate in den alten Bundesländern: Substanzstörungen, unipolare Depressionen, somatoforme Störungen, soziale Phobien und Essstörungen waren zum Erhebungszeitpunkt in den alten Bundesländern signifikant häufiger als in den Neuen. Hingegen ergab sich für die neuen Bundesländern eine geringfügig schlechtere Zufriedenheit in mehreren Lebensbereichen, während die subjektive gesundheitsbezogene Lebensqualität in den neuen Bundesländern signifikant besser beurteilt wird. Schlussfolgerungen: Die psychische Gesundheit (definiert als Abwesenheit manifester psychischer Störungen) der Bevölkerung in den neuen Bundesländern ist entgegen den Befunden früherer Fragebogenstudien besser als die in den alten Bundesländern; lediglich die Lebenszufriedenheit ist tendenziell schlechter! Diese Befunde unterstreichen, dass die Prävalenzrate psychischer Störungen relativ robust gegenüber regionalen und gesellschaftlichen Einflüssen ist.
Lebensalterspezifische Veränderungen phonologischer Defizite bei Lese-Rechtschreibstörung
Authors: Georgiewa Petra , Grünling Carolin , Ligges Marc , Filz Christina , Möller Ulrich , Blanz Bernhard
Published: October 2004

Zusammenfassung. Theoretischer Hintergrund: Die klinischen Symptome der LRS ändern sich im Laufe der Entwicklung der Patienten, wobei sich die altersabhängigen Veränderungen der Lesefähigkeit aber von normgerechter Leseentwicklung unterscheiden. Fragestellung: Der Charakter dieser Veränderungen soll anhand der Entwicklung von Lesefertigkeiten in verschiedenen Lebensaltern gezeigt werden. Methoden: 102 Personen mit LRS und 91 normallesenden Kontrollen aus drei Altersgruppen (Kinder, Jugendliche und Erwachsenen) wurden Leseaufgaben vorgegeben, die unterschiedliche phonologische Strategien verlangen: (1) lautes Lesen von Wörtern, (2) von Nonwörtern und (3) Phonemtransformation. Erfasst wurden Lesefehler und -zeiten. Ergebnisse: Eine Verbesserung der Lesefertigkeiten erfolgt kontinuierlich über die drei Altersgruppen. Erwachsene mit LRS erreichen nicht einmal das Wortleseniveau jugendlicher Kontrollen. Beim Nonwortlesen sind sie schlechter als normallesende Kinder und erreichen über die Altersstufen kaum signifikante Verbesserungen. Schlussfolgerungen: In der LRS-Gruppe bilden sich Fähigkeiten zur Graphem-Phonem-Transformation langsamer heraus und bleiben auf niedrigem Niveau. Verbesserungen der Wortlesefähigkeiten scheinen vor allem über lexikalische Strategien (Ganzwortlesen) möglich.
Kognitive Verhaltenstherapie bei Depressionen im Klimakterium:
Authors: Ayen Irmgard , Hautzinger Martin
Published: October 2004

Zusammenfassung. Theoretischer Hintergrund: Obgleich bei Frauen im Klimakterium psychische Beschwerden bis hin zu Depressionen häufig sind, gibt es bislang kaum eine angemessene fachliche Auseinandersetzung geschweige denn spezifische Therapieangebote für diese Zielgruppe. Fragestellung: Kurz- und langfristige Wirkungen einer kognitiv-verhaltenstherapeutischen Gruppenintervention im Vergleich zu einer unterstützenden Gruppentherapie und einer Wartekontrollgruppe bei Frauen mit Depressionen im Klimakterium. Methode: An der Studie nahmen 51 depressive Frauen teil. Die Interventionsphase belief sich auf drei Monate bei wöchentlichen Kontakten. Veränderungen und Effekte wurden vor, während und nach der Intervention per Selbst- und Fremdbeurteilungen erfasst. Nachuntersuchungen fanden bis ein Jahr nach Ende der Intervention statt. Ergebnisse: Die Interventionsgruppen wiesen bei der Postmessung signifikante Verbesserungen der depressiven Symptombelastung auf, die auch in der Katamnese anhielten. Dabei erwies sich die kognitiv-verhaltenstherapeutische Intervention mit einer Effektstärke von d = 2,9 (bezogen auf Depressionssymptome) im Vergleich zum Effekt des Wartens als deutlich erfolgreicher als die unspezifische, unterstützende Intervention mit d = 1,9. Bei der Kontrollgruppe ergaben sich während der Wartezeit keine (positiven) Veränderungen. Bedeutsame Verbesserungen zeigten sich auch in der klimakterischen Symptombelastung. Schlussfolgerung: Die spezifische und die unspezifische Gruppeninterventionen haben sich als niederschwelliges Therapieangebot für depressive Frauen im Klimakterium bewährt. Dabei erwies sich die kognitiv-verhaltenstherapeutische Intervention einem unterstützenden, unspezifischen Gruppenangebot kurz- und längerfristig überlegen.
Substorm injection modeling with nondipolar, time‐dependent background field
Authors: Zaharia Sorin , Birn J. , Friedel R. H. W. , Reeves G. D. , Thomsen M. F. , Cheng C. Z.
Published: October 2004

We model energetic particle injections during substorms by investigating the particle interaction with an earthward propagating electromagnetic pulse of spatially localized transient electric (E) and magnetic (B) fields, superposed over a background B field. The current work extends our previous model by considering the background field to be nondipolar (stretched) before the arrival of the pulse (i.e., during the substorm growth phase), changing in a time‐dependent manner into a dipole field in the wake of the pulse. The particle motion still conserves the first adiabatic invariant, even in the stretched B field, and both protons and electrons are convected earthward by the E × B drift to regions of higher field, undergoing betatron acceleration. As in the previous model, we find fully analytical solutions for the gyrocenter motion of the 90° pitch angle particles, and we use them to compute the injected particle flux. We discuss how the model can explain several injection features such as the low/high energy cutoffs, and finally we apply the solutions to a simulation of an actual injection event, obtaining good agreement with observations. The current results with the more realistic background field show significant increase in particle flux for “substorm energies” (tens to hundreds of keVs) compared with the case of a dipole background, leading to the conclusion that the particles have to arrive from closer to Earth than before in order to explain the observed injected flux levels. The new model provides a better fit to observations than the previous one, since it requires lower transient E fields (more realistic of a typical substorm), and thus better explains the ubiquity of particle injections associated with substorms.
Energy partition in two solar flare/CME events
Authors: Emslie A. G. , Kucharek H. , Dennis B. R. , Gopalswamy N. , Holman G. D. , Share G. H. , Vourlidas A. , Forbes T. G. , Gallagher P. T. , Mason G. M. , Metcalf T. R. , Mewaldt R. A. , Murphy R. J. , Schwartz R. A. , Zurbuchen T. H.
Published: October 2004

Using coordinated observations from instruments on the Advanced Composition Explorer (ACE), the Solar and Heliospheric Observatory (SOHO), and the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), we have evaluated the energetics of two well‐observed flare/CME events on 21 April 2002 and 23 July 2002. For each event, we have estimated the energy contents (and the likely uncertainties) of (1) the coronal mass ejection, (2) the thermal plasma at the Sun, (3) the hard X‐ray producing accelerated electrons, (4) the gamma‐ray producing ions, and (5) the solar energetic particles. The results are assimilated and discussed relative to the probable amount of nonpotential magnetic energy available in a large active region.
Analytical solution of the diffusion equation in a cylindrical medium with step-like diffusivity
Authors: Clémençon A. , Guivarch C. , Eury S. P. , Zou X. L. , Giruzzi G.
Published: October 2004

The exact analytical solution of the one-dimensional diffusion equation in a cylinder has been found, for a medium characterized by a diffusion coefficient with step-like and/or monomial variations, in addition to a constant damping term. This type of equation has important applications in the field of magnetically confined plasmas, in the presence of a transport barrier. A sharp variation of the heat diffusivity can also result from the microturbulence that develops whenever the temperature gradient exceeds a critical value. This analytical solution can be used to model the evolution, in space and time, of the electron temperature of a plasma heated up by an external source, the step in the heat diffusion coefficient being related to the space location of the critical temperature gradient. The general properties of the solution and its application to the analysis of perturbative electron heating experiments are discussed.
Simultaneous short-range smoothening and global roughening during growth of hydrogenated amorphous silicon films
Authors: Sperling Brent A. , Abelson John R.
Published: October 2004

We investigate the evolution of surface morphology during hot-wire chemical vapor deposition of amorphous silicon films onto rough substrates. Using in situ spectroscopic ellipsometry, we find that the surface smoothens as the film grows. However, postdeposition atomic force microscopy reveals that the roughness is actually increasing linearly. We resolve this discrepancy by examining the power spectrum densities of the atomic force images, which indicate that the growth surface experiences both short-range smoothening and global roughening. The ellipsometry data are consistent with the short-range atomic force microscopy data, but they exclude information about the long-range components of roughness. The slope of the power spectrum density indicates surface diffusion is the dominant smoothening mechanism; the linear increase in roughness is consistent with columnar growth caused by self-shadowing.
Electron acceleration by overlapped plasma waves
Authors: Lin Hai , Xu Zhizhan , Li Ruxin , Chen Li-Ming
Published: October 2004

The electron acceleration in two counterpropagating plasma waves is investigated on the basis of the discussion on the general form of a nonlinear plasma wave. The velocity history of the untrapped electrons and that of the trapped electrons in two counterpropagating plasma waves are calculated. Numerical results indicate that the maximum velocity of a trapped electron in two waves is dependent on the ratio between the amplitudes of two waves.
Semiclassical wave-packet scattering in one and two dimensions
Authors: Rothstein Ivan
Published: October 2004

We prove that under short range potentials a semiclassical wave packet’s propagation is accurate for infinite times in the ℏ→0 limit.
High-Q ring resonators in thin silicon-on-insulator
Authors: Baehr-Jones Tom , Hochberg Michael , Walker Chris , Scherer Axel
Published: October 2004

We have fabricated high-Q microrings from thin silicon-on-insulater SOI layers and measured Q values of 45 000 in these rings, which were then improved to 57 000 by adding a PMMA cladding. The optimal waveguide designs were calculated, and the waveguide losses were analyzed. These high-Q resonators are expected to lead to interesting devices for telecommunication filters and sources as well as optical refractive index sensing.