bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical properties of the electrically silent adult rat soleus muscle
Authors: Roy Roland R. , Zhong Hui , Monti Ryan J. , Vallance Kevin A. , Edgerton V.R.
Published: September 2002

The isometric and isotonic in situ mechanical properties of the soleus muscle of adult female rats were determined after 60 days of inactivity induced by spinal cord isolation (SI). Compared to control, the absolute muscle mass, physiological cross‐sectional area, and maximum tetanic tension of the soleus in SI rats were reduced by 69%, 66%, and 77%, respectively. Isometric twitch time‐to‐peak‐tension and half‐relaxation times were 41% and 60% shorter in SI than control rats. The maximum velocity of shortening (mm/s), as determined using the afterloaded technique, was 66% faster in SI than control rats, whereas unloaded shortening velocity was similar in the two groups (9% faster in SI rats). Peak power was 48% lower in SI than control rats. The SI soleus was 39% more fatigable than control. Thus, the soleus became a smaller, faster, and more fatigable muscle following 60 days of inactivity. In general, the results indicate that the adaptations are of a lesser magnitude than those reported previously following denervation for the same duration. These data provide a baseline for future efforts to experimentally define the mechanisms of neurally mediated, but activity‐independent, regulation of the mechanical properties of the rat soleus muscle. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 404–412, 2002
Embedding iterated line digraphs in books
Authors: Hasunuma Toru
Published: September 2002

In this paper, we present an upper bound on the pagenumber of an iterated line digraph Lk(G) of a digraph G. Our bound depends only on the digraph G and is independent of the number of iterations k. In particular, it is proved that the pagenumber of Lk(G) does not increase with the number of iterations k. This result generalizes previous results on book‐embeddings of some particular families of iterated line digraphs such as de Bruijn digraphs, Kautz digraphs, and butterfly networks. Also, we apply our result to wrapped butterfly networks. © 2002 Wiley Periodicals, Inc.
Regulation of c‐Ret, GFRα1, and GFRα2 in the substantia nigra Pars compacta in a rat model of Parkinson's disease
Authors: Marco Sònia , Saura Josep , Pérez‐Navarro Esther , José Martí María , Tolosa Eduard , Alberch Jordi
Published: September 2002

Glial cell line‐derived neurotrophic factor (GDNF) family members have been proposed as candidates for the treatment of Parkinson's disease because they protect nigral dopaminergic neurons against various types of insult. However, the efficiency of these factors depends on the availability of their receptors after damage. We evaluated the changes in the expression of c‐Ret, GFRα1, and GFRα2 in the substantia nigra pars compacta in a rat model of Parkinson's disease by in situ hybridization. Intrastriatal injection of 6‐hydroxydopamine (6‐OHDA) transiently increased c‐Ret and GFRα1 mRNA levels in the substantia nigra pars compacta at 1 day postlesion. At later time points, 3 and 6 days, the expression of c‐Ret and GFRα1 was downregulated. GFRα2 expression was differentially regulated, as it decreased only 6 days after 6‐OHDA injection. Triple‐labeling studies, using in situ hybridization for the GDNF family receptors and immunohistochemistry for neuronal or glial cell markers, showed that changes in the expression of c‐Ret, GFRα1, and GFRα2 in the substantia nigra pars compacta were localized to neurons. In conclusion, our results show that nigral neurons differentially regulate the expression of GDNF family receptors as a transient and compensatory response to 6‐OHDA lesion. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 343–351, 2002
Short window of opportunity for calpain induced growth cone formation after axotomy of Aplysia neurons
Authors: Gitler Daniel , Spira Micha E.
Published: September 2002

Our laboratory has established that local activation of calpain by a transient elevation of the free intracellular calcium concentration is crucial for the induction of growth cone (GC) formation in cultured Aplysia neurons. The mechanisms and stages in which calpain is involved in the formation of a GC are not known. We began to study these questions by determining the nature of calpain's action and the stages in which calpain activity affects the cascade of events that leads to the formation of the GC and its extension. We report that the calpain‐dependent transformation of an axonal segment into a GC occurs within a narrow window of opportunity that lasts approximately 5 min. If calpain is inhibited during this window of opportunity, GC formation does not occur. Inhibition of calpain after the window of opportunity slows down the rate of lamellipodial extension but doesn't arrest it. The proteolysis of spectrin, a calpain substrate and a major component of the membrane skeleton, occurs within this window of opportunity, in agreement with the hypothesis that spectrin proteolysis is an early step in the formation of the GC. If the onset of proteolysis is deferred, spectrin remains unchanged and GC formation is compromised. We suggest that calpain participates in two different processes: it is critical for the triggering of GC formation and plays a modulatory role during the extension of the GC's lamellipodia. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 267–279, 2002
Female canaries that respond and discriminate more between male songs of different quality have a larger song control nucleus (HVC) in the brain
Authors: Leitner Stefan , Catchpole Clive K.
Published: September 2002

In male songbirds the song control pathway in the forebrain is responsible for song production and learning. In most species, females do not sing and have smaller nuclei in the song control pathway.Although the function of the pathway in females is assumed to be associated with the perception of male song, there is little direct evidence to support this view. In this study on female canaries, we investigate the role of two key nuclei in the song control pathway (HVC and lMAN) in relation to playback of male song. Male canaries produce elaborate songs that function to attract and stimulate females. The songs are constructed from smaller units called syllables, and special syllables with a more complex structure (sexy syllables) are known to induce females to perform copulation solicitation displays (CSD) as an invitation to mate. By using computer‐edited experimental songs, we first show that females discriminate between songs by producing significantly more CSD to those containing sexy syllables. We then sectioned the brains and usedin situhybridization to reveal song nuclei containing androgen receptors. We report positive correlations between the size of HVC and both total CSD response and the amount of discrimination between sexy and nonsexy songs. We found no such relationships between these measures and the size of lMAN. These results provide some evidence to support the view that, in female canaries HVC is involved in female perception and discrimination of male song. The results also have implications for the evolution of complex male songs by sexual selection and female choice. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 294–301, 2002
Changing patterns of ganglion cell coupling and connexin expression during chick retinal development
Authors: Becker David L. , Bonness Viola , Catsicas Marina , Mobbs Peter
Published: September 2002

We have used dye injection and immunolabeling to investigate the relationship between connexin (Cx) expression and dye coupling between ganglion cells (GCs) and other cells of the embryonic chick retina between embryonic days 5 and 14 (E5–14). At E5, GCs were usually coupled, via soma‐somatic or dendro‐somatic contacts, to only one or two other cells. Coupling increased with time until E11 when GCs were often coupled to more than a dozen other cells with somata in the ganglion cell layer (GCL) or inner nuclear layer (INL). These coupled clusters occupied large areas of the retina and coupling was via dendro‐dendritic contacts. By E14, after the onset of synaptogenesis and at a time of marked cell death, dye coupling was markedly decreased with GCs coupled to three or four partners. At this time, coupling was usually to cells of the same morphology, whereas earlier coupling was heterogeneous. Between E5 and E11, GCs were sometimes coupled to cells of neuroepithelial morphology that spanned the thickness of the retina. The expression of Cx 26, 32, and 43 differed and their distribution changed during the period studied, showing correlation with events such as proliferation, migration, and synaptogenesis. These results suggest specific roles for gap junctions and Cx's during retinal development. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 280–293, 2002
Regeneration of retinal axons in the lizard Gallotia galloti is not linked to generation of new retinal ganglion cells
Authors: Lang Dirk M. , del Mar Romero‐Aleman Maria , Arbelo‐Galvan Juan‐Francisco , Stuermer Claudia A.O. , Monzon‐Mayor Maximina
Published: September 2002

Using anterograde tracing with HRP and antibodies (ABs) against neurofilaments, we show that regrowth of retinal ganglion cell (RGC) axons in the lizard Gallotia galloti commences only 2 months after optic nerve transection (ONS) and continues over at least 9 months. This is unusually long when compared to RGC axon regeneration in fish or amphibians. Following ONS, lizard RGCs up‐regulate the immediate early gene C‐JUN for 9 months or longer, indicating their reactive state. In keeping with the in vivo data, axon outgrowth from lizard retinal explants is increased above control levels from 6 weeks, reaches its maximum as late as 3 months, and remains elevated for at least 1 year after ONS. By means of BrdU incorporation assays and antiproliferating cell nuclear antigen immunohistochemistry, we show that the late axon outgrowth is not derived from new RGCs that might have arisen in reaction to ONS: no labeled cells were detected in lizard retinas at 0.5, 1, 1.5, 3, 6, and 12 months after ONS. Conversely, numbers of RGCs undergoing apoptosis were too low to be detectable in TUNEL assays at any time after ONS. These results demonstrate that retinal axon regeneration in G. galloti is due to axon regrowth from the resident population of RGCs, which remain in a reactive state over an extended time interval. Neurogenesis does not appear to be involved in RGC axon regrowth in G. galloti. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 322–335, 2002
On the classical shell model underlying bilinear degenerated shell finite elements: general shell geometry
Authors: Malinen Mika
Published: September 2002

We study the shell models arising in the numerical modelling of shells by geometrically incompatible finite elements. We build a connection from the so‐called bilinear degenerated 3D FEM to the classical 2D shell theory of Reissner–Naghdi type showing how nearly equivalent finite element formulations can be constructed within the classical framework. The connection found here facilitates the mathematical error analysis of the bilinear elements based on the degenerated 3D approach. In particular, the connection reveals the ‘secrets’ that relate to the treatment of locking effects within this formulation. Copyright © 2002 John Wiley & Sons, Ltd.
Active control of FGM shells subjected to a temperature gradient via piezoelectric sensor/actuator patches
Authors: Liew K. M. , He X. Q. , Ng T. Y. , Kitipornchai S.
Published: September 2002

A generic static and dynamic finite element formulation is derived for the modelling and control of piezoelectric shell laminates under coupled displacement, temperature and electric potential fields. The base shell is of functionally graded material (FGM) type, which consists of combined ceramic–metal materials with different mixing ratios of the ceramic and metal constituents. A multi‐input–multi‐output (MIMO) system is applied to provide active feedback control of the laminated shell using self‐monitoring sensors and self‐controlling actuators through a close loop. Numerical studies clearly show the influence of the positional configurations of sensor/actuator pairs on the effectiveness of static and dynamic control for the shell laminates. The effects of the constituent volume fractions on the static and dynamic responses of the shell laminate are also elucidated. Copyright © 2002 John Wiley & Sons, Ltd.
High‐order predictor–corrector algorithms
Authors: Lahmam H. , Cadou J. M. , Zahrouni H. , Damil N. , Potier‐Ferry M.
Published: September 2002

New predictor–corrector algorithms are presented for the computation of solution paths of non‐linear partial differential equations. The predictors and the correctors are based on perturbation techniques and Padé approximants. This extends the Asymptotic Numerical Method (ANM), which is an efficient high‐order continuation technique without corrector. The efficiency and the reliability of the new technique are assessed by several examples within thin shell theory and Navier–Stokes equations. Many variants have been tested to establish an optimal algorithm. Copyright © 2002 John Wiley & Sons, Ltd.
An improved four‐node hybrid‐mixed element based upon Mindlin's plate theory
Authors: Ayad Rezak , Rigolot Alain
Published: September 2002

Based on the mixed shear projected (MiSP) approach (Reference [54]: Int. J. Numer. Meth. Engng 1998; 42:1149–1179), an enhanced bending approximation for homogeneous isotropic plates is presented. Some hard benchmark tests, such as the skew plate (30°) problem, have often shown poor convergence when low‐order elements (3‐ or 4‐node element) are developed using linear approximations for kinematic variables. To put right this weakness, we propose a high‐order interpolation for rotational dofs which results in more rich bending curvatures. The mid‐side rotational nodes are eliminated using a combination of local discrete kinematic and constitutive Mindlin hypotheses. The derived 4‐node quadrilateral element, called MiSP4+, is free of shear locking and passes all patch tests for thick and thin plates in an arbitrary mesh. Copyright © 2002 John Wiley & Sons, Ltd.
Axisymmetric modal analysis of liquid‐storage tanks considering compressibility effects
Authors: Cho J. R. , Kim K. W. , Lee J. K. , Park T. H. , Lee W. Y.
Published: September 2002

In this paper, we address analytical and numerical studies on the free vibration of fluid–structure interaction problems considering the fluid compressibility. According to the separation of variables together with the boundary condition enforcement, we first derive a compressible‐fluid velocity potential function. Next, we split the structure region into the wet and dry parts, for which we apply the Novozhilov thin shell theory. Combining two dynamic displacement fields, for two split structure parts, using the displacement compatibility conditions, we finally obtain a simultaneous equation system for computing natural frequencies and modes. According to the derived analytical formulae, we compute natural frequencies and modes, stress resultants, together with the comparison with the FEM analysis and the incompressible case. Numerical results show, compared to the incompressible case, that the compressible case produces lower natural frequencies and, furthermore, the relative difference is influenced by the slenderness of tanks and the relative liquid fill height. Copyright © 2002 John Wiley & Sons, Ltd.
Tragedy Reshapes the American Workplace: A Symposium with Lynn Martin
Authors: Williams Sandra L.
Published: September 2002

In March 2002, the Midwest Workplace Symposium was sponsored by the Union League Club of Chicago. The

discussion explored leadership needs, cultural management issues, and the reshaping of attitudes and values at

American businesses in the post‐9/11 environment. A panel of business experts gathered to share

observations and provide insight into future challenges facing domestic and international commerce. The honorable

Lynn Martin, former Secretary of Labor, facilitated the group. This article details salient portions of their

discussion. © 2002 Wiley Periodicals, Inc.
The Principles of High Performance—and How to Apply Them
Authors: Martel Leon
Published: September 2002

General principles emerge from the practices of the best companies in work content and the work environment,

recruiting and hiring, compensation and benefits, and education and training. Several of these principles are

universally found, others are exhibited by a number of the best companies, and some are only suggested by the

directions in which a few of the companies are heading. In addition, several may seem counterintuitive or contrary

to current advice. But all are consistent with the structural changes occurring in the nature of work and the values

of workers. © 2002 Wiley Periodicals, Inc.
Discovering the Value of Executive Coaching as a Business Transformation Tool
Authors: Niemes Jim
Published: September 2002

Today's transformation initiatives—everything from Enterprise Resource Planning to Six

Sigma—often require the development of new abilities in a company's leaders. Executive coaching is a

powerful tool that can be used to rapidly introduce new skills into a company's leadership ranks. For both

high‐potential executives and those newly entrusted with high‐level leadership,

one‐on‐one executive coaching can meet developmental, not remedial, needs. Getting it right,

though, requires willing participants, a robust measurement system, careful feedback, a feedback‐based

action plan, and strong follow‐up. © 2002 Wiley Periodicals, Inc.
Histamine induces the phosphorylation of a 58 KDa protein in GT1‐7 neuronal cells
Authors: Zamani M. Reza , Leeson Andrea H. , Nash Joanne , Bristow David R.
Published: September 2002

Exposure to histamine mediates homologous histamine H1 receptor desensitisation by a process involving calcium/calmodulin‐dependent protein kinase II (CaMKII). This suggests a direct involvement of a phosphorylation cascade during desensitisation. Here we investigated histamine‐induced substrate phosphorylation in mouse hypothalamic GT1‐7 neuronal cells. CaMKII activity was detected in GT1‐7 cell extracts incubated with [32P]ATP and autocamtide, a selective CaMKII substrate, which was inhibited by 1‐[N,O‐Bis(5‐isoquinolinesulfonyl)‐N‐methyl‐L‐tyrosyl]‐4‐phenylpiperazine (KN‐62). [32P]orthophosphate‐loaded GT1‐7 cells were exposed to histamine (30 µM, 30 min) with or without KN‐62. Phosphopeptide autoradiograms were generated after 2‐dimensional SDS‐gel (2D‐gel) electrophoresis and the integrated intensity quantified with 2D‐image analysis. Histamine induced the phosphorylation of a 58 kDA phosphoprotein that was prevented by KN‐62. The phosphorylation of this 58 kDa protein suggests a negative feedback step in the signal transduction cascade that results in H1 receptor desensitisation.
A stereological estimation of total neuron number and volume of the hippocampus at one and seven day‐old chicks
Authors: Sahin B. , Aslan H. , Canan S. , Kaplan S. , Unal B. , Odacı E.
Published: September 2002

Hippocampal complex of the avian brain is one of the most studied brain regions in recent years. This structure is thought to be homologous to mammalian hippocampus and have an important role in spatial memory. Connection patterns between the avian hippocampus and other brain regions strongly support the idea of homology between mammalian and avian hippocampal complexes.

Total neuron number of chick hippocampus in different ages was estimated using optical fractionator counting method. Animals were separated into two groups as one day‐ and seven day‐old chicks. The mean total number of nerve cells in the right hippocampi of one day‐old and seven day‐old chicks was estimated as 783 310 ± 12 749 and 760 028 ± 12 256 respectively. The difference between two groups was not statistically significant (p > 0.05).

The mean total volume of hippocampi of chicks was estimated by Cavalieri's principle and it was found to be 2.48 ± 0.08 mm3 for one day‐old chicks and 2.80 ± 0.04 mm3 for seven day‐old chicks. The difference between these volume values was statistically significant (p < 0.01).

Although the difference in total neuron numbers between two groups was not raised statistically significant level, decreasing cell number with age might be depend on the destruction of unneeded nerve cells with aging. The increased volume in seven day‐old group may be associated with enlargement due to several reasons during development.
A fractional splitting algorithm for nonoverlapping domain decomposition for parabolic problem
Authors: Daoud Daoud S. , Subasi D.
Published: September 2002

In this article we study the convergence of the nonoverlapping domain decomposition for solving large linear system arising from semi‐discretization of two‐dimensional initial value problem with homogeneous boundary conditions and solved by implicit time stepping using first and two alternatives of second‐order FS‐methods. The interface values along the artificial boundary condition line are found using explicit forward Euler's method for the first‐order FS‐method, and for the second‐order FS‐method to use extrapolation procedure for each spatial variable individually. The solution by the nonoverlapping domain decomposition with FS‐method is applicable to problems that requires the solution on nonuniform meshes for each spatial variable, which will enable us to use different time‐stepping over different subdomains and with the possibility of extension to three‐dimensional problem. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 609–624, 2002
Toward anisotropic mesh construction and error estimation in the finite element method
Authors: Kunert Gerd
Published: September 2002

Directional, anisotropic features like layers in the solution of partial differential equations can be resolved favorably by using anisotropic finite element meshes. An adaptive algorithm for such meshes includes the ingredients Error estimation and Information extraction/Mesh refinement. Related articles on a posteriori error estimation on anisotropic meshes revealed that reliable error estimation requires an anisotropic mesh that is aligned with the anisotropic solution. To obtain anisotropic meshes the so‐called Hessian strategy is used, which provides information such as the stretching direction and stretching ratio of the anisotropic elements. This article combines the analysis of anisotropic information extraction/mesh refinement and error estimation (for several estimators). It shows that the Hessian strategy leads to well‐aligned anisotropic meshes and, consequently, reliable error estimation. The underlying heuristic assumptions are given in a stringent yet general form. Numerical examples strengthen the exposition. Hence the analysis provides further insight into a particular aspect of anisotropic error estimation. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 625–648, 2002; DOI 10.1002/num.10023
Assessing JPAM after 20 Years
Authors: Reuter Peter , Smith‐Ready Jeri
Published: September 2002

JPAM aims to be the principal research journal for public policy scholars. A citation

analysis of JPAM and competitor journals for the period 1986–1995 shows that

JPAM's most frequently cited articles are cited more often than those of other broad

policy journals, about as often as those in journals on specific policy areas, except for health policy, and

less often than principally methodological journals. JPAM does meet its goal of serving as an

outlet primarily for public policy scholars and it covers a wide range of policy topics. A survey of subscribers

shows correspondingly broad interests and that members rated the journal among their most valued. However, few

articles are frequently cited, very few of the citations appear in major journals, and the range of disciplines

represented is narrow. Some suggestions are offered for strengthening the journal. © 2002 by the

Association for Public Policy Analysis and Management.
Agency governance and enforcement: the influence of mission on environmental decisionmaking
Authors: Firestone Jeremy
Published: September 2002

Administrative agencies seeking to impose sanctions for regulatory violations can handle matters internally or

through civil or criminal courts. Organizational culture, legal constraints, and political and private actors may

influence governance and hence choice of enforcement venue. An enforcement behavior model is constructed and tested

empirically using a 1990–1997 sample of Environmental Protection Agency (EPA) air, water, and

hazardous waste penalty cases involving individuals. While EPA's enforcement arm embraces the mission of its

regulatory arm—minimizing environmental harm—in part, it also has attributes of a police and

prosecution force—specifically deterring (and maximizing social welfare) or incapacitating

individual violators. Nevertheless, EPA may fail to minimize violations of and generally deter non‐culpable

individuals who are affiliated with large firms. © 2002 by the Association for Public Policy Analysis and

Management.
Swelling behaviors of polyelectrolyte hydrogels containing sulfonate groups
Authors: Atta Ayman M.
Published: September 2002

Series of maleate monoester and diester monomers based on poly(ethylene glycol) monomethyl ether (MPEG) were copolymerized using the ionizable 2‐acrylamido‐2–methyl propane sulfonic acid (AMPS) via different dose rate of electron‐beam irradiation (40–150 kGy). The crosslinking of the copolymers were carried out in aqueous acidic solutions at pH 1 or in the presence of 1% N,N‐methylene bisacrylamide (MBA) as crosslinking agent. The final equilibrium water content and swelling capacities for the prepared hydrogels were determined in aqueous solutions at pH 1, 6.8, and 12 and in aqueous salt solutions at 298 K. Swelling equilibria for prepared hydrogels were determined in different molar salt solutions of NaCl, KCl, CaCl2, Na2SO4, K2SO4, and CaSO4. The swelling ratios of gels in pure water and in the salt solutions were found to depend on the counterion species in the increasing sequence of Ca2+, Na+ and K+. Copyright © 2002 John Wiley & Sons, Ltd.
Electromagnetic interference shielding by using conductive polypyrrole and metal compound coated on fabrics
Authors: Lee C. Y. , Lee D. E. , Jeong C. K. , Hong Y. K. , Shim J. H. , Joo J. , Kim M. S. , Lee J. Y. , Jeong S. H. , Byun S. W. , Zang D. S. , Yang H. G.
Published: September 2002

Electromagnetic interference (EMI) shielding materials of complex type of conductive polypyrrole (PPy) as an intrinsically conducting polymer and silver‐palladium (AgPd) metal compound coated on woven or non‐woven fabrics are synthesized. From dc conductivity and SEM photographs of PPy/fabric complexes, we discuss charge transport mechanism and the homogeneity of coating on the fabrics. The EMI shielding efficiency of PPy/fabric and AgPd/fabric complexes is in the range of 8 ∼ 80 dB depending on the conductivity and the additional Ag vacuum evaporation. The highest EMI shielding efficiency of PPy/fabric complexes vacuum‐evaporated by Ag is ∼80 dB, indicating potential materials for military uses. We propose that PPy/fabrics are excellent RF and microwave absorber because of the relatively high absorbance and low reflectance of the materials. Copyright © 2002 John Wiley & Sons, Ltd.
Cholesteric mixture containing chiral‐photochromic and diarylethene dopants as novel material with dual photochromism
Authors: Bobrovsky A. , Boiko N. , Shibaev V. P. , Zavarzin I. , Kalik M. , Krayushkin M.
Published: September 2002

New cholesteric polymeric mixture containing nematic side‐chain homopolymer, 2 wt% of photochromic diarylethene dopant and 5 wt% of chiral‐photochromic dopant based on cinnamic acid and isosorbide was prepared. Upon UV irradiation of planarly‐oriented mixture films at room temperature, a transformation of open colorless form of diarylethene dopant into a closed colored form takes place, which is followed by the appearance of an intense absorption maximum in the visible spectral region and decreasing selective light reflection intensity. This process is photo‐ and thermo‐reversible and many cycles ‘recording‐erasing’ can be realized. UV irradiation and subsequent annealing of the films lead to untwisting of the cholesteric helix and cause an irreversible shift of selective light reflection to the long‐wavelength region. This process is explained by the E‐Z isomerization of chiral photochromic groups of the dopant relative to a CC bond accompanied by a decrease in their twisting ability.

It has been shown, that the use of the material prepared in this work provides an opportunity to record two images at the same time: one image is due to a change in the helical pitch and another (second) image is due to the photochromism of diarylethene dopant. It is pertinent to note that using the approach developed in this work allows one to widely vary the range of materials exhibiting dual photochromism. It was demonstrated that the mixture under study shows advantage as new photosensitive material for optics, optoelectronics and data recording. Copyright © 2002 John Wiley & Sons, Ltd.
Association of British Clinical Diabetologists
Authors: Wales John , Essex Nina , Fox Charles , Singh Dev , Wroe James
Published: September 2002

Members of the Association of British Clinical Diabetologists (ABCD) from all over the United Kingdom met for two days in the congenial atmosphere of The Jury's Ballsbridge Hotel in Dublin to discuss two important medico‐political/professional topics: the National Service Framework for Diabetes and its implications for secondary diabetes care; and the role and responsibilities of the diabetes specialist nurse in relation to those of the diabetologist. The meeting was an opportunity also for delegates to debate the clinical significance of postprandial hyperglycaemia and to update and inform themselves through state‐of‐the‐art lectures and discussions on a range of other interesting and relevant clinical issues. Copyright © 2002 John Wiley & Sons, Ltd.
The Oxford International Diabetes Summit: Implications of the DAWN study
Authors: Roglic Gojka , Matthews David , Rubin Richard R , Bech Ole Molskov
Published: September 2002

The DAWN (Diabetes Attitudes, Wishes and Needs) study was instigated by Novo Nordisk in order to assess the perceptions and attitudes of people with diabetes and health care providers to the management and care of diabetes. The study was conducted between August 2000 and September 2001 in 11 countries or regions: Australia, France, Germany, India, Japan, Poland, Spain, The Netherlands, United Kingdom, Scandinavia (Denmark, Norway and Sweden) and the USA, with the focus on drivers of effective self‐management amongst over 5400 people with diabetes and over 3800 diabetes health care providers (specialist doctors, GPs and nurses).

The objective of the DAWN study was to provide information of value in improving diabetes care and the well being of diabetic patients and to enhance and complement data derived from other reported psychosocial studies. To this end, the first Oxford DAWN International Summit met to consider its implications and resolve ways in which the findings of the DAWN study could be implemented. The interactive nature of the summit was enhanced by the use of computer‐linked individual keypads, so that delegates could participate interactively and vote on a range of issues. Following presentations on the key issues surrounding DAWN, a series of participant workshops considered the issues that had been raised and produced their recommendations for future action.

Opening the Summit, Chairman Dr David Matthews (Chairman of the Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford, UK) commented on its multi‐national and multi‐disciplinary nature and how this was bringing together different stakeholder perspectives. Use of the keypads showed that Denmark, USA, Germany and the UK (in that order) were the best represented. Delegates included diabetologists, nurses, behavioural scientists, GPs, patients and health payors. These different perspectives would be important in arriving at conclusions. The DAWN study had endeavoured to discover the person behind the patient and to establish to what degree self‐care management truly involved a partnership between patient and health care provider. Dr Matthews emphasised the psychosocial nature of the survey and the ways in which this aspect of care had perhaps been somewhat neglected in the past. DAWN represented an opportunity for change; this challenge should be welcomed. He hoped that the outcome of the summit would have a long lasting effect over the coming years. Copyright © 2002 John Wiley & Sons, Ltd.
Fast transient fluorescence technique for studying swelling of gels made at various crosslinker contents and exposed to organic vapour
Authors: Erdoǧan M , Yönel B , Pekcan Ö
Published: September 2002

Fast transient fluorescence technique (FTRF) was employed for studying swelling of disc‐shaped poly(methyl methacrylate) (PMMA) gels, which were prepared by free radical copolymerization of methyl methacrylate (MMA) using various ethylene glycol dimethacrylate (EGDM) contents at 60 °C. Pyrene (P) was introduced as a fluorescence probe during polymerization. Swelling experiments were performed by using P‐doped PMMA gels under chloroform vapor. Decay curves of P were measured during in situ swelling experiments. Exponential fits were performed to measure pyrene lifetimes, τ, inside the PMMA gels. It was observed that τ values decreased as swelling proceeded. An equation is derived for low quenching efficiencies to interpret the behaviour of P lifetimes during swelling. The Li–Tanaka equation was used to determine the cooperative diffusion coefficients, Dc, for the gels made at various crosslinker contents. It is observed that Dc values decrease as the crosslinker content is increased.

© 2002 Society of Chemical Industry
Structural relaxation in poly(ethylene terephthalate) studied by positron annihilation lifetime spectroscopy
Authors: Sathyanarayana P M , Shariff Gani , Thimmegowda M C , Ashalatha M B , Ramani R , Ranganathaiah C
Published: September 2002

Positron lifetime technique was used to study the physical ageing process in poly(ethylene terephthalate) (PET). Positron lifetime results show that the structural relaxation processes in PET encompass two different time regimes, one short and the other long. The relaxation function constructed from the measured o‐Ps intensity I3 exhibits non‐exponential character, which can be best fitted with two additive exponentials. The Narayanaswamy model (Kohlraush‐William Watt (KWW) function) is invoked to extract the stretching parameter β indicating the extent of deviation from exponential relaxation. Based on the relaxation times, the activation energies calculated seem to label the different kinetic units of PET structure participating in the relaxation process.

© 2002 Society of Chemical Industry
Phase separation in blends of linear polymers formed in situ according to different mechanisms
Authors: Lipatov Y S , Kosyanchuk L F , Nesterov A F
Published: September 2002

The in situ formation of blends of two incompatible polymers was studied. The kinetics of simultaneously proceeding reactions of radical polymerization of methyl methacrylate and polyaddition reaction of polyurethane formation was investigated for various ratios of monomeric compounds in the reaction mixture. It was established that the kinetics of formation of each polymer in the mixture depends on the presence of the other and on the kinetics of its formation. These parallel reactions are accompanied by phase separation at a definite conversion degree of each monomer. The onset of phase separation does not affect the course of the kinetic curves. The regularities of phase separation in connection with reaction kinetics were investigated by light scattering. It was found that because of the difference in the rates of the two reactions, the ratio of the polymers formed in the reaction mixture continually changes in time. In spite of this, initial stages of the phase separation may be considered as proceeding according to the spinodal mechanism. Values of amplification factors were calculated which depend on the component ratio and reaction rates. It was established that reaction‐induced phase separation determines the formation of the interconnected morphology immediately after the onset of phase separation, when the composition of the polymer blends has not yet reached its equilibrium value.

© 2002 Society of Chemical Industry
Active sites deterioration of MgCl2‐supported catalyst induced by the electron donor extraction by alkylaluminium
Authors: Matsuoka Hitoshi , Liu Boping , Nakatani Hisayuki , Nishiyama Isa , Terano Minoru
Published: September 2002

To investigate the role of the internal donor in a Ziegler–Natta catalyst, the nature and existing states of the internal donor were intentionally varied by alkylaluminium treatment before polymerization, and the catalytic properties during propene polymerization were accurately evaluated using the stopped‐flow method. A significant decrease in the amount of the remaining internal donor was observed during the initial stage of the extraction. The polymerization results show a gradual decrease in the polymer isotacticity with an increase in the extraction time. These different patterns, as a function of the extraction time, indicate that the amount of the remaining internal donor is not directly related to the isotacticity of the produced polymer.

© 2002 Society of Chemical Industry
Scale‐up of adsorptive styrene drying
Authors: Rivero María J , Gorri Daniel , Ibáñez Raquel , Ortiz Inmaculada
Published: September 2002

This work is focused on the analysis of the scale‐up process of styrene drying by adsorption onto activated alumina as a necessary step in the manufacture of styrene–butadiene rubber. In a previous work, the mathematical model was developed and the design parameters were estimated from the fitting of the model to experimental results obtained in a laboratory set‐up. The obtained model and parameters have been used to simulate the behaviour of a pilot plant that contains up to 56 times more sorbent stating their validity after comparison with experimental results. Finally, the behaviour of an industrial plant presently at work, was also satisfactorily described. The ability of the model to simulate experimental results obtained on three different scales checks its adequacy for process design and optimization.

© 2002 Society of Chemical Industry
Proton and electron radiation data and analysis of GaInP2/GaAs/Ge solar cells
Authors: Sharps P. R. , Aiken D. J. , Stan M. A. , Thang C. H. , Fatemi Navid
Published: September 2002

We present electron and proton radiation data for our GaInP2/GaAs/Ge triple‐junction solar cell. An analysis of the data is also done with both the relative damage coefficients (RDC) method developed at NASA‐JPL, as well as the displacement damage dose (D3) method developed by the Naval Research Laboratory. We also discuss radiation tolerance of cells in the light of our development of an advanced triple‐junction cell. Copyright © 2002 John Wiley & Sons, Ltd.
Space and terrestrial photovoltaics: synergy and diversity
Authors: Bailey Sheila G. , Raffaelle Ryne , Emery Keith
Published: September 2002

A historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the 1970s and 1980s, 1990s and beyond. The synergy of both communities, both at the beginning and in the present, and hopefully in the future, are highlighted, with examples of the important features in each program. The space community which was impressed by the light weight and reliability of photovoltaics drove much of the early development. Even today, nearly every satellite and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems was only a small fraction of the satellite and launch cost, the use of much of this technology in the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advances, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost nonexistent. Recent work by both communities have focused on the development thin‐film cells of amorphous silicon, CuInSe2and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and terrestrial solar cell communities shall once again share many common goals and, in fact, companies may manufacture both space and terrestrial solar cells in III–V materials and thin‐film materials. Basic photovoltaics research, including these current trends in nanotechnology, provides a valuable service for both worlds in that fundamental understanding of cell processes is still vitally important, particularly with new materials or new cell structures. It is entirely possible that one day we might have one solar array design that will meet the criteria for success in both space and on the Earth or perhaps the Moon or Mars. Published in 2002 by John Wiley & Sons, Ltd.
Nonlinear characteristics of the quantitative relationship between the glass‐transition temperature and the structure of homopolymers
Authors: Sun Hong , Tang Yingwu , Zhang Fushi , Wu Guoshi , Chan Shek‐Kiu
Published: September 2002

Fuzzy set theory was used to study the relationship between the glass‐transition temperature (Tg) and structure of homopolymers. The method can map the relationship and give the Tg for 235 polymers with a standard deviation of 8 K (the confidence bound was 90%). The entropy of the fuzziness was used to quantitatively describe the interactions among groups. The method was used to predict the Tg of 10 polymers not included in the 235 polymers, with a standard deviation of 9 K (the confidence bound was 90%). The study demonstrates again that fuzzy set theory can be effectively used to investigate the quantitative structure–property relationship of polymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2164–2169, 2002
Effect of aqueous and organic solutions on the performance of polyamide thin‐film‐composite nanofiltration membranes
Authors: Kim In‐Chul , Jegal Jonggeon , Lee Kew‐Ho
Published: September 2002

Polyamide/polyacrylonitrile thin‐film‐composite (TFC) nanofiltration (NF) membranes for the separation of oleic acid dissolved in organic solvents (methanol and acetone) were interfacially prepared by the reaction of trimesoyl chloride in an organic phase with an aqueous phase containing piperazine and m‐phenylene diamine. The interfacial reaction was confirmed by an investigation of the attenuated total reflection infrared spectrum. The surface morphology of the polyamide TFC membranes was examined with scanning electron microscopy. The hydrophilic properties of the membrane surfaces were conjectured on the basis of the ζ potential and contact angle. The effects of the monomer concentrations of the monomer blends (aliphatic and aromatic diamines) and drying times on various aspects of membrane performance, such as the solvents (water, alcohols, ketones, and hexane), permeation rates, and organic solute [poly(ethylene glycol) 200 and oleic acid] rejection rates, were investigated. All the membranes showed good solvent resistance. The polar solvent flux for water and methanol was higher than that for a nonpolar solvent (hexane). The membranes gave good rejection rates of oleic acid dissolved in methanol and acetone. The NF membranes were compared with various commercial membranes. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2151–2163, 2002
Pore size distributions in low‐k dielectric thin films from X‐ray porosimetry
Authors: Lee Hae‐Jeong , Soles Christopher L. , Liu Da‐Wei , Bauer Barry J. , Wu Wen‐Li
Published: September 2002

X‐ray reflectivity has been used to determine the mass uptake of probe molecules in porous thin films supported on thick silicon wafers. The adsorption occurs by capillary condensation when the films are exposed to probe vapor at controlled partial vapor pressures. The probe solvent partial pressure was varied by mixing saturated air and dry air at constant temperature or by changing sample temperature at a constant vapor concentration. Pore size distribution in the films can be calculated from the probe uptake with typical porosimetric approaches such as the application of the Kelvin equation to convert partial pressure into pore size. For illustration, the pore size distribution of three different nanoporous thin films, the primary candidate of ultra‐low‐k interlevel dielectrics in the next generation of integrated circuit chips, was determined with this technique. These samples represent different generations of low‐k dielectrics developed by industry. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2170–2177, 2002
Gas permeability and n‐butane solubility of poly(1‐trimethylgermyl‐1‐propyne)
Authors: Nagai Kazukiyo , Toy Lora G. , Freeman Benny D. , Teraguchi Masahiro , Kwak Giseop , Masuda Toshio , Pinnau Ingo
Published: September 2002

The gas permeability and n‐butane solubility in glassy poly(1‐trimethylgermyl‐1‐propyne) (PTMGP) are reported. As synthesized, the PTMGP product contains two fractions: (1) one that is insoluble in toluene and soluble only in carbon disulfide (the toluene‐insoluble polymer) and (2) one that is soluble in both toluene and carbon disulfide (the toluene‐soluble polymer). In as‐cast films, the gas permeability and n‐butane solubility are higher in films prepared from the toluene‐soluble polymer (particularly in those films cast from toluene) than in films prepared from the toluene‐insoluble polymer and increase to a maximum in both fractions after methanol conditioning. For example, in as‐cast films prepared from carbon disulfide, the oxygen permeability at 35 °C is 330 × 10−10 cm3 (STP) cm/(cm2 s cmHg) for the toluene‐soluble polymer and 73 × 10−10 cm3 (STP) cm/(cm2 s cmHg) for the toluene‐insoluble polymer. After these films are conditioned in methanol, the oxygen permeability increases to 5200 × 10−10 cm3 (STP) cm/(cm2 s cmHg) for the toluene‐soluble polymer and 6200 × 10−10 cm3 (STP) cm/(cm2 s cmHg) for the toluene‐insoluble polymer. The rankings of the fractional free volume and nonequilibrium excess free volume in the various PTMGP films are consistent with the measured gas permeability and n‐butane solubility values. Methanol conditioning increases gas permeability and n‐butane solubility of as‐cast PTMGP films, regardless of the polymer fraction type and casting solvent used, and minimizes the permeability and solubility differences between the various films (i.e., the permeability and solubility values of all conditioned PTMGP films are similar). © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2228–2236, 2002