bluuebunny/crossref_metadata_2025 huggingface dataset:
A nonexistence result for Yamabe type problems on thin annuli
Authors: Ben Ayed Mohamed , El Mehdi Khalil , Hammami Mokhless
Published: October 2002

Given any constant

C>0

, we show that there exists

ε_0>0

such that for any

ε<ε_0

, the problem

P_{ɛ}: - \Delta u_{ɛ} = u_{ɛ}^{\left(n + 2\right)/ \left(n - 2\right)},u_{ɛ} > 0

in

A_{ɛ}

;

u_{ɛ} = 0

on

\partial A_{ɛ}

, has no solution

u_ε

, whose energy,

∫_{A_ε}|∇u_ε|^2

, is less than

C

, where

A_ε

is a ringshaped open set in

ℝ^{n}

and

n⩾4

.

Etant donné une constante positive

C

arbitraire, nous montrons qu'il existe

ε_0>0

tel que pour tout

ε<ε_0

, le problème

p_{ɛ}: - \Delta u_{ɛ} = u_{ɛ}^{\left(n + 2\right)/ \left(n - 2\right)},u_{ɛ} > 0

dans

A_{ɛ}

;

u_{ɛ} = 0

sur

\partial A_{ɛ}

, ne possède pas de solution

u_ε

dont l'energie,

∫_{A_ε}|∇u_ε|^2

, est plus petite que

C

, où

A_ε

est un ouvert de

ℝ^{n}

ayant la forme d'un anneau et

n⩾4

.
Biosynthetic response and mechanical properties of articular cartilage after injurious compression
Authors: Kurz Bodo , Jin Moonsoo , Patwari Parth , Cheng Debbie M. , Lark Michael W. , Grodzinsky Alan J.
Published: October 2002

Traumatic joint injury is known to produce osteoarthritic degeneration of articular cartilage. To study the effects of injurious compression on the degradation and repair of cartilage in vitro, we developed a model that allows strain and strain rate‐controlled loading of cartilage explants. The influence of strain rate on both cartilage matrix biosynthesis and mechanical properties was assessed after single injurious compressions. Loading with a strain rate of 0.01 s−1 to a final strain of 50% resulted in no measured effect on the cells or on the extracellular matrix, although peak stresses reached levels of about 12 MPa. However, compression with strain rates of 0.1 and 1 s−1 caused peak stresses of approximately 18 and 24 MPa, respectively, and resulted in significant decreases in both proteoglycan and total protein biosynthesis. The mechanical properties of the explants (compressive and shear stiffness) were also reduced with increasing strain rate. Additionally, cell viability decreased with increasing strain rate, and the remaining viable cells lost their ability to exhibit an increase in biosynthesis in response to low‐amplitude dynamic mechanical stimulation. This latter decrease in reparative response was most dramatic in the tissue compressed at the highest strain rates. We conclude that strain rate (like peak stress or strain) is an important parameter in defining mechanical injury, and that cartilage injuriously compressed at high strain rates can lose its characteristic anabolic response to low‐amplitude cyclic mechanical loading. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Integrative cartilage repair: adhesive strength is correlated with collagen deposition
Authors: Dimicco Michael A. , Sah Robert L.
Published: October 2002

Procedures to repair focal articular cartilage defects often result in poor integration between the host cartilage and the graft tissue, and this may be related to the lack of matrix deposition and the death of chondrocytes near a cut cartilage surface. The objective of this study was to determine if cartilage repair was related to deposition of newly synthesized collagen. The mechanical integration that occurred between two live adult bovine cartilage blocks cultured in partial apposition for two weeks was correlated with [3H]proline incorporation, a measure of protein synthesis, of which more than 66% was accounted for by collagen. A similar level of mechanical integration occurred in sample pairs consisting of a live and killed cartilage block, and this adhesive strength was also correlated with [3H]proline deposition into both the live and the killed blocks. In these samples, the [3H]proline deposited into the killed cartilage appeared to originate from chondrocytes in the live cartilage, since live cells were not detected in the killed cartilage block by either viability staining or [35S]sulfate incorporation. These results suggest a mechanism of integrative cartilage repair in which live chondrocytes within cartilage secrete matrix molecules that are components of a collagen network, and subsequent deposition of these molecules near the repair interface contributes to functional integration. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
BMP‐12 gene transfer augmentation of lacerated tendon repair
Authors: Lou Jueren , Tu Yizheng , Burns Meghan , Silva Matthew. J. , Manske Paul
Published: October 2002

Bone morphogenetic protein (BMP) 12 is a recently discovered member of the human BMP family. It is the human homolog of mouse growth/differentiation factor (GDF)‐7. Previously we reported that injection of mesenchymal progenitor cells transferred with the BMP‐12 gene into the muscles of nude mice induced tendon‐like tissue formation. In this study, we further investigated the effect of BMP‐12 gene transfer on tendon cells. We observed that adenovirus mediated in vitro BMP‐12 gene transfer into chicken tendon cells increased type I collagen synthesis. No change in alkaline phosphatase activity was observed following BMP‐12 gene transfer. We also determined that BMP‐12 gene transfer into a complete tendon laceration chicken model resulted in a two‐fold increase of tensile strength and stiffness of repaired tendons, indicating improved tendon healing in vivo. We conclude that BMP‐12 gene transfer is a promising procedure for improving the tendon repair process. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Controlled‐release of IGF‐I and TGF‐β1 in a photopolymerizing hydrogel for cartilage tissue engineering
Authors: Elisseeff Jennifer , McIntosh Winnette , Fu Karen , Blunk Torsten , Langer Robert
Published: October 2002

Photopolymerizing hydrogel systems provide a method to encapsulate cells and implant materials in a minimally invasive manner. Controlled release of growth factors in the hydrogels may enhance the ability to engineer tissues. IGF‐I and TGF‐β were loaded in PLGA microspheres using a double emulsion technique. 125 ng and 200 pg of active IGF‐I and TGF‐β, respectively, as measured by ELISA, were released over 15 days. The growth factor containing microspheres were photoencapsulated with bovine articular chondrocytes in PEO‐based hydrogels and incubated in vitro for two weeks. Statistically significant changes in glycosaminoglycan (GAG) production compared to control gels either without microspheres or with blank spheres were observed after a 14 day incubation with IGF‐I and IGF‐I/TGF‐β microspheres combined, with a maximum density of 8.41 ± 2.5% wet weight GAG. Total collagen density was low and decreased with the IGF‐I/TGF‐β microspheres after two weeks incubation, but otherwise remained unchanged in all other experimental groups. Cell content increased 10‐fold to 0.18 ± 0.056 × 106 cells/mg wet weight and extracellular matrix (ECM) staining by H&E increased in hydrogels with IGF‐I/TGF‐β microspheres. In conclusion, photoencapsulation of microspheres in PEO‐based hydrogels provides a method to deliver molecules such as growth factors in porous hydrogel systems. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Measurement of material elastic constants of trabecular bone: a micromechanical analytic study using a 1 GHz acoustic microscope
Authors: Jørgensen C. S. , Kundu T.
Published: October 2002

The propagation speed (C) of surface acoustic waves (SAW), e.g. Rayleigh (R‐waves) and longitudinal lateral waves (L‐waves), the latter being the surface manifestation of the longitudinal waves, strongly reflect mechanical properties of materials. In view of an increasing interest in ultrasonic methodology in the field of bone biomechanics, we tested the hypothesis that both R‐ and L‐waves can be excited in trabecular bone using an acoustic microscope at 1 GHz and that their speeds (CR and CL) can be extracted from V(z)‐curves, i.e. plots of lens output voltage as a function of the lens focal point position with respect to the specimen surface. In accordance with V(z)‐curves theoretically synthesized on the basis of incident field theory, experimental curves for canine femoral trabecular bone showed evidence of both R‐ and L‐waves in almost all regions of recording. The measured CR ranged between 1.93 and 2.07 km/s (mean ± SD.: 2.00 ± 0.06 km/s) and the CL ranged between 2.33 and 4.33 km/s (3.37 ± 0.61 km/s). Knowledge of both speeds allowed computation of a number of material constants by means of simple theory of elasticity and assumptions of the material density. We found values of Poisson ratio (v) ranging from 0.14 to 0.32 (0.23 ± 0.07), Young's modulus (E) from 15 to 22.8 GPa (19.9 ± 2.5 GPa) and the shear modulus (G) from 7.6 to 8.9 GPa (8.4 ± 0.5 GPa). Anisotropy in the trabecular bone material was clearly detected at the micrometer level. In conclusion, the V(z)‐curve method was successfully used to determine the distribution of material elastic constants of trabecular bone with micrometer resolution. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The knee adduction moment during gait in subjects with knee osteoarthritis is more closely correlated with static alignment than radiographic disease severity, toe out angle and pain
Authors: Hurwitz D. E. , Ryals A. B. , Case J. P. , Block J. A. , Andriacchi T. P.
Published: October 2002

This study tested whether the peak external knee adduction moments during walking in subjects with knee osteoarthritis (OA) were correlated with the mechanical axis of the leg, radiographic measures of OA severity, toe out angle or clinical assessments of pain, stiffness or function. Gait analysis was performed on 62 subjects with knee OA and 49 asymptomatic control subjects (normal subjects). The subjects with OA walked with a greater than normal peak adduction moment during early stance (p = 0.027). In the OA group, the mechanical axis was the best single predictor of the peak adduction moment during both early and late stance (R = 0.74, p < 0.001). The radiographic measures of OA severity in the medial compartment were also predictive of both peak adduction moments (R = 0.43 to 0.48, p < 0.001) along with the sum of the WOMAC subscales (R = −0.33 to −0.31, p < 0.017). The toe out angle was predictive of the peak adduction moment only during late stance (R = −0.45, p < 0.001). Once mechanical axis was accounted for, other factors only increased the ability to predict the peak knee adduction moments by 10–18%. While the mechanical axis was indicative of the peak adduction moments, it only accounted for about 50% of its variation, emphasizing the need for a dynamic evaluation of the knee joint loading environment. Understanding which clinical measures of OA are most closely associated with the dynamic knee joint loads may ultimately result in a better understanding of the disease process and the development of therapeutic interventions. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Age‐related variations in the microstructure of human tibial cancellous bone
Authors: Ding Ming , Odgaard Anders , Linde Frank , Hvid Ivan
Published: October 2002

A thorough understanding of the microstructure of cancellous bone is crucial for diagnosis, prophylaxis, and treatment of age‐related skeletal diseases. Until now, little has been known about age‐related variations in the microstructure of peripheral cancellous bone. This study quantified age‐related changes in the three‐dimensional (3D) microstructure of human tibial cancellous bone. One hundred and sixty cylindrical cancellous bone specimens were produced from 40 normal proximal tibiae from 40 donors, aged 16–85 years. These specimens were micro‐computed tomography (micro‐CT) scanned, and microstructural properties were determined. The specimens were then tested in compression to obtain Young's modulus.

The degree of anisotropy, mean marrow space volume, and bone surface‐to‐volume ratio increased significantly with age. Bone volume fraction, mean trabecular volume, and bone surface density decreased significantly with age. Connectivity did not have a general relationship with age. Bone volume fraction together with anisotropy best predicted Young's modulus. Age‐related changes in the microstructural properties had the same trends for both medial and lateral condyles of the tibia. The observed increase of anisotropy and constant connectivity suggest a bone remodeling mechanism that may reorient trabecular volume orientation in aging tibial cancellous bone. The aging trabeculae align more strongly to the primary direction ‐ parallel to the tibial longitudinal loading axis. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Static and dynamic compression modulate matrix metabolism in tissue engineered cartilage
Authors: Davisson Twana , Kunig Sabine , Chen Albert , Sah Robert , Ratcliffe Anthony
Published: October 2002

Static and dynamic compression are known to modulate the metabolism of articular cartilage. The present study focused on determining the effects of compressive loading on the metabolism of sulfated glycosaminoglycans (S‐GAG) and protein in tissue engineered cartilage constructs. Cartilage constructs were subjected to static or dynamic compression for 24 h and radiolabeled with 35SO4 and 3H‐proline to assess the total synthesis and percentage retention of S‐GAG and total protein, respectively. Static compression at an amplitude of 50% suppressed the synthesis of both S‐GAG and protein by 35% and 57%, respectively. Dynamic compression at an amplitude of 5% had stimulatory effects on synthesis that were dependent on the static offset compression amplitude (10% or 50%) and dynamic compression frequency (0.001 or 0.1 Hz). Thus, tissue engineered cartilage demonstrated the ability to respond to mechanical loading in a manner similar to that observed with articular cartilage. Mechanical loading may therefore potentially be used to modulate the growth of cartilaginous tissues in vitro, potentially facilitating the culture of functional cartilage tissues suitable for implantation. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
In vivo study of hot compressing molded 50:50 poly (DL‐lactide‐co‐glycolide) antibiotic beads in rabbits
Authors: Ueng Steve W. N. , Yuan Li‐Jen , Lee Ning , Lin Song‐Shu , Liu Shih‐Jung , Chan Err‐Cheng , Weng Jui‐Hsun
Published: October 2002

The authors investigated poly (DL‐lactide‐co‐glycolide) beads as an antibiotic delivery system in vivo for the treatment of various surgical infections. In this study, the copolymer 50:50 poly (DL‐lactide):co‐glycolide was mixed with vancomycin powder and hot compressing molded at 55°C to form 8 mm in diameter biodegradable antibiotic beads. The antibiotic beads were implanted in the distal femoral cavities of rabbits for in vivo investigation. The local concentration of vancomycin was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial killing and resistance to the antibiotic) for 56 days. The release was most marked during the first day. The diameters of the sample inhibition zone ranged from 8 to 18 mm, and the relative activity of vancomycin ranged from 9.1% to 100%. Only low systemic blood levels of vancomycin were measured after beads implantation. There was no increase in the concentration of blood urea nitrogen and serum creatinine after the implantation. Histological observations showed that the bead materials were biodegradable, resorbed slowly, and did not cause a significant host reaction. This study offers a biodegradable delivery system of antibiotics to treat various surgical infections. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Mechanical loads at the knee joint during deep flexion
Authors: Nagura Takeo , Dyrby Chris O. , Alexander Eugene J. , Andriacchi Thomas P.
Published: October 2002

There is a lack of fundamental information on the knee biomechanics in deep flexion beyond 90°. In this study, mechanical loads during activities requiring deep flexion were quantified on normal knees from 19 subjects, and compared with those in walking and stair climbing. The deep flexion activities generate larger net quadriceps moments (6.9–13.5% body weight into height) and net posterior forces (58.3–67.8% body weight) than routine ambulatory activities. Moreover, the peak net moments and the net posterior forces were generated between 90° and 150° of flexion.

The large moments and forces will result in high stress at high angles of flexion. These loads can influence pathological changes to the joint and are important considerations for reconstructive procedures of the knee. The posterior cruciate ligament should have a substantial role during deep flexion, since there was a large posterior load that must be sustained at the knee. The mechanics of the knee in deep flexion are likely a factor causing problems of posterior instability in current total knee arthroplasty. Thus, it is important to consider the magnitude of the loads at the knee in the treatment of patients that commonly perform deep flexion during activities of daily living. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The effect of low intensity pulsed ultrasound applied to rabbit tibiae during the consolidation phase of distraction osteogenesis
Authors: Tis John E. , Meffert Rainer H. , Inoue Nozomu , McCarthy Edward F. , Shaun Machen M. , McHale Kathleen A. , Chao Edmund Y. S.
Published: October 2002

The purpose of this study was to determine if low intensity pulsed ultrasound (LIPU) accelerated the maturation of regenerate bone when applied after distraction in a rabbit model. A mid‐tibial osteotomy was performed in 26 New Zealand white rabbits and an external fixator applied anteromedially. After a seven day latency period, the tibiae were distracted 0.5 mm every 12 h for 10 days. Thirteen of the rabbits received LIPU for 20 min/day (treatment group) and 13 received sham LIPU (control group) from day 17 until sacrifice on day 37. Radiographs were taken weekly after distraction and the total and mineralized areas of the callus were measured. After sacrifice, dual‐energy X‐ray absorptiometry, torsional testing to failure, and histomorphometry were performed. Ultrasound‐treated tibiae were a mean of 68.8 ± 3.8% as stiff as and 68.2 ± 6.0% as strong as the contralateral tibiae. Control tibiae were 78.7 ± 7.0% as stiff as and 70.2 ± 7.9% as strong as the contralateral tibiae. The differences in stiffness and strength were not significant (p = 0.39 and 0.81, respectively) with the number of the animals tested in the study. The treatment group was 91.6% as dense as the contralateral side and the control group was 88.5% as dense as the contralateral side (p = 0.84). Radiographs revealed a significantly larger callus in the LIPU‐treated tibiae at 1, 2 and 3 weeks after distraction compared to control tibiae (p < 0.01, 0.008 and 0.05, respectively). Histomorphometry revealed significantly less fibrous tissue in the LIPU‐treated tibiae (p < 0.05) and a strong trend towards more bone in the LIPU‐treated tibiae compared to controls (p = 0.06). LIPU was found to increase the size of the distraction callus and it might alter the composition of regenerate bone but it did not have a positive effect on the mechanical properties or density of regenerate bone when applied during the consolidation phase of distraction osteogenesis. Published by Elsevier Science Ltd. on behalf of Orthopaedic Research Society. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Nestin expression persists in astrocytes of organotypic slice cultures from rat cortex
Authors: Schmidt‐Kastner Rainald , Humpel Christian
Published: October 2002

Nestin is an intermediate filament protein typical for neural precursor cells that is down‐regulated in the post‐natal rodent brain. Re‐expression of nestin has been observed in reactive astrocytes after injury. In this study, organotypic slice cultures from rat cortex were examined for expression of nestin and glial fibrillary acidic protein between 2 and 8 weeks in culture. Immunoreactivity for nestin and glial fibrillary acidic protein was seen in astrocytes which persisted throughout the observation period. Immunofluorescence double labeling showed widespread co‐localization of nestin and glial fibrillary acidic protein. Image analysis revealed that levels of nestin‐immunoreactivity plateaued after 5 weeks in culture. By comparison nestin immunoreactivity was absent from glial cells of the cortex in mature rats. These immunohistochemical findings of a persistent expression of nestin in glial cells of organotypic slice culture of the rat cortex indicate a different time course of glial maturation in vitro. This difference could be related to the altered trophic stimulation in vitro; differences in neuronal maturation, activity or survival; slow degeneration of the vasculature; or intrinsic properties of astrocytes.
Party support or personal resources? Factors of success in the plurality portion of the 1999 national legislative elections in Russia
Authors: Golosov Grigorii V.
Published: October 2002

The paper estimates party-related and non-party-related factors of electoral success in single-member district elections to the Russian State Duma in December 1999. As demonstrated by the analysis, both kinds of factors facilitate candidates’ performance, but the utility of personal political resources of non-electoral origins is greater than that of party support. Thus it is likely to be valued by Russian politicians as a supplement, not as a core component of their electoral strategies. By distorting the structure of incentives for elite partisanship, this situation conserves party system underdevelopment in the country.
Echocardiographic prediction of long‐term response to biventricular pacemaker in severe heart failure
Authors: Oguz Enis , Dagdeviren Bahadir , Bilsel Tuba , Akdemir Osman , Erdinler Izzet , Akyol Ahmet , Ulufer Tanju , Tezel Tuna , Gurkan Kadir
Published: October 2002

Background:

Biventricular pacing substantially improves LV systolic function and symptom status in some patients with dilated cardiomyopathy.

Aims:

To assess whether the long‐term benefit could be predicted from the echocardiographic parameters.

Methods and Results:

Sixteen patients with dilated cardiomyopathy who underwent atrio‐biventricular pacemaker implantation were analyzed in two groups: the responders (n‐11) were those with a symptomatic improvement of one or more NYHA functional class; the non‐responders (n‐5) failed to improve at follow‐up (7.6±5 months). Echocardiography was performed at baseline, the day after the implantation and then every 3 months. Besides the conventional parameters, the following variables were included: LV diastolic filling time (DFT); the duration of mitral regurgitation (dMR); and LV dP/dt obtained from the continuous wave mitral regurgitation curve. While the baseline DFT and dP/dt were not significantly different between non‐responders and responders (256±105 vs. 358±115, P‐0.14 and 564±199 vs. 468±117, P‐0.44, respectively), the QRS width (149±15 vs. 175±24 ms, P‐0.05) and the dMR (343±70 vs. 443±49 ms, P‐0.007) were higher in the responders. The changes of dMR, DFT and QRS width by pacing were not significantly different between groups (P‐0.18, 0.30 and 0.77, respectively). However, the change of LV dP/dt by pacing in the responders was significantly different than for non‐responders (from 468±117 to 676±216 mmHg/s vs. from 564±199 to 483±94, P‐0.002). An acute increase in LV dP/dt over 22% by pacing yielded only two false negatives and no false positives in predicting the long‐term responsiveness.

Conclusion:

Patients with longer QRS and dMR are more likely to benefit from atrio‐biventricular stimulation. The acute changes of Doppler derived LV dP/dt may provide valuable information in predicting the long‐term response to biventricular pacing.
Hypomagnesemia and concurrent acid–base and electrolyte abnormalities in patients with congestive heart failure
Authors: Milionis Haralampos J. , Alexandrides George E. , Liberopoulos Evangelos N. , Bairaktari Eleni T. , Goudevenos John , Elisaf Moses S.
Published: October 2002

Background:

Patients with severe decompensated congestive heart failure (CHF) commonly exhibit acid–base and electrolyte disturbances mainly due to the activation of several neurohumoral mechanisms as well as to drugs regularly used in this population. Magnesium deficit is not infrequently observed in CHF patients but its pathophysiology remains less well‐studied as compared with other electrolyte alterations, such as hypokalemia. However, there is evidence that early detection and correction of magnesium abnormalities could obviate potentially deleterious arrhythmogenic effects.

Aim:

To assess the incidence of magnesium level disorders and analyze the underlying pathophysiological mechanisms in patients with CHF.

Methods:

Eighty‐six consecutive CHF patients (NYHA class III or IV) admitted to our hospital over a period of 5 years were studied. Patients with diabetes mellitus, liver or renal failure, and chronic obstructive lung disease were excluded. All patients received conventional treatment with digoxin, diuretic agents and an angiotensin converting enzyme inhibitor. On admission, blood and urine electrolytes and renal function parameters were determined. Arterial blood gases and serum anion gap determinations were also performed.

Results:

Hypomagnesemia was found in 15 [n ‐ 15 (17.4%)] CHF patients. The majority of these patients also exhibited other electrolyte abnormalities, such as hypokalemia, hypocalcemia and hypophosphatemia. Inappropriate magnesiuria (fractional excretion of magnesium >4%) was evident in eight hypomagnesemic patients. A variety of associated conditions, including poor dietary intake, also favored magnesium depletion.

Conclusion:

Magnesium deficit is a common electrolyte disorder in CHF (NYHA class III/IV) patients and several interrelated mechanisms are implicated in its pathogenesis. Clinicians’ awareness of the incidence of hypomagnesemia in this population as well as its related pathophysiology could be useful for the early detection and appropriate treatment to inhibit its arrhythmogenic potential.
Urban Expansion Simulation of Southeast England Using Population Surface Modelling and Cellular Automata
Authors: Wu Fulong , Martin David
Published: October 2002

The question of where to accommodate future urban expansion has become a politically sensitive issue in many regions. Against the backdrop of ‘urban compaction’ policy, this study uses population surface modelling and cellular automata (CA) to conduct an empirical urban growth simulation for Southeast England. This implementation leads to a consideration of the proper balance between the theoretical abstraction of self-organised growth and empirical constraints to land development. Specifically, we use 1991 and 1997 postcode directories to construct population surfaces. From these, the distributions of developed and vacant (rural) land are derived. Development potential is assessed through accessibility surfaces, which are constructed from the travel/commuting time to major London rail termini, to motorway junctions, and to principal settlements. Through investigating the frequencies of land development in relation to the accessibility surfaces, we can begin to understand the distribution of land development in this region. Based on this empirical relationship, the transition rules of a CA simulation of future urban expansion are constructed. In addition, government population projections at the county level are used to constrain simulation to the year 2020. The study demonstrates the utility of empirical CA in urban growth modelling; in particular the importance of empirically informed CA simulation rules in characterising the distribution of land development.
Changing Discourses in China Geography: A Narrative Evaluation
Authors: Lin George C S
Published: October 2002

Existing literature on the status of the field of China geography has been focused either on what has been written or on the internal advancement of knowledge in the field, without considering its relationship to the broader social context and academic environment. In this study I adopt a contextual approach to analyzing two interrelated issues: (1) the changing position held by China geography in the grand geographic discipline; and (2) the evolution of discourses formulated by China geographers as a result of interactions with the broader academic environment. A systematic survey of research papers published in leading international journals has placed China geography in a peripheral position, with a volume of research output disproportionate to the size and importance of the nation. Nevertheless, several encouraging trends are observed, including the dramatic growth of research output since the 1990s and the broadening of the field beyond physical geography to encompass human geography and urban studies. A narrative investigation of the professional experience of a leading China geographer reveals a process of discourse (re)construction conditioned by both the changing political economy of China and the shifting emphases in the geographic discipline. Four periods of discourse formation are identified in this case study, namely the conception of the Chinese city as the center of change in the 1970s, interpretation of the uniqueness of Chinese urbanism in the 1980s, modeling of spontaneous town-based urbanization and regional development in the 1990s, and, most recently, the use of the notions of space, place, and transnationalism to construct the Chinese diaspora as a geographic system. Discourse formation in China geography can be understood as the consequence both of the rapidly changing material conditions in China and of discursive practices in the geographic discipline. Much needs to be done by China geographers to go beyond the empirical arena of area studies and become more actively engaged in the ongoing theoretical debates in the mainstream of geography and China studies.
Transformation of a Boundary Regime: The Hong Kong and Mainland China Case
Authors: Breitung Werner
Published: October 2002

Since 1997 the border between Hong Kong and Mainland China has been officially referred to as a boundary, instead of a border. In this paper the author analyses to what extent actual changes in cross-border interactions support this notional change. It points to an ongoing step-by-step integration process on the functional level. The main empirical basis of this analysis is a survey on cross-border trips in 1999, supplemented by additional data. In looking at the changing boundary regime between Hong Kong and Mainland China the author also develops a framework for the study of border regimes and their transformation in general.
Environmental Regulation of Land Use and Public Compensation: Principles, and Swiss and Australian Examples
Authors: Seidl Irmi , Tisdell Clement A , Harrison Steve
Published: October 2002

The authors discuss the regulation of rural land use and compensation for property-rights restrictions, both of which appear to have become more commonplace in recent years but also more contested. The implications of contemporary theories in relation to this matter are examined, including: the applicability of new welfare economics; the relevance of the neoclassical theory of politics; and the implications of contemporary theories of social conflict resolution and communication. Examination of examples of Swiss and Australian regulation of the use of rural properties, and the ensuing conflicts, reveals that many decisions reflect a mixture of these elements. Rarely, if ever, are social decisions in this area made solely on the basis of welfare economics, for instance social cost-benefit analysis. Only some aspects of such decisions can be explained by the neoclassical theory of politics. Theories of social conflict resolution suggest why, and in what way, approaches of discourse and participation may resolve conflicts regarding regulation and compensation. These theories and their practical application seem to gain in importance as opposition to government decisions increases. The high degree of complexity of most conflicts concerning regulation and compensation cannot be tackled with narrow economic theories. Moreover, the Swiss and Australian examples show that approaches involving conflict resolution may favour environmental standards.
Spatial-Economic Investment Policy and Urban Regeneration in the Netherlands
Authors: Priemus Hugo
Published: October 2002

The Netherlands has a certain reputation in the areas of spatial policy, infrastructure policy, and urban policy. In the 1980s the national governments of many countries became less directly involved, with the consequence that spatial policy and urban policy were left more to the marketplace. In that period, this trend could also be observed in the Netherlands. Since the mid-1990s, however, in the Netherlands there has been a new public commitment to infrastructure policy and urban policy, and also to spatial policy. In this paper I account for this marked change of course by the extra profits which the Netherlands has received, particularly since the 1990s, from excise duty on natural gas and government income from the privatization of government services. Privatization and the export of natural gas have enabled the Dutch government to put more public investment into the development of traffic infrastructure and the regeneration of cities.
Haptic Pictures: Fit Judgments Predict Identification, Recognition Memory, and Confidence
Authors: Kennedy John M , Bai Juan
Published: October 2002

D'Angiulli et al (1998 Scandinavian Journal of Psychology39 187–190) found blind and sighted (blindfolded) children identified common objects in raised-outline drawings explored haptically, and corrected themselves without feedback. The self-correction suggests that participants can assess the extent to which the referents they suggest as possible identifications fit the haptic pictures. Indeed, when we asked subjects to identify haptic pictures, and to judge how well the referents they mentioned fitted the pictures, their fit judgments predicted the accuracy of their suggestions. Also, when one group of subjects offered the suggestions and another group assessed the fit of the suggestions to the pictures, the fit judgments predicted the accuracy of the suggestions. Further, good fit predicted successful recognition memory. In addition, both high and low fit judgments were made confidently, so the range of confidence judgments was smaller than the range of fit judgments. Finally, visual judgments of fit by one group predicted the level of success of the suggestions from another (haptic) group. In sum, subjects assess their suggested identifications appropriately, most likely on the basis of object shape criteria, outlined surface edges, and use of a vantage point.
Exploring Levels of Face Familiarity by Using an Indirect Face-Matching Measure
Authors: Clutterbuck Ruth , Johnston Robert A
Published: October 2002

An experiment is reported in which participants matched complete images of unfamiliar, moderately familiar, and highly familiar faces with simultaneously presented images of internal and external features. Participants had to decide if the two images depicted same or different individuals. Matches to internal features were made faster to highly familiar faces than both to moderately familiar and to unfamiliar faces, and matches to moderately familiar faces were made faster than to unfamiliar faces. For external feature matches, this advantage was only found for “different” decision matches to highly familiar faces compared to unfamiliar faces. The results indicate that the differences in familiar and unfamiliar face processing are not the result of all-or-none effects, but seem to have a graded impact on matching performance. These findings extend the earlier work of Young et al (1985 Perception14 737–746), and we discuss the possibility of using the matching task as an indirect measure of face familiarity.
Achieving the holy grail of seamless CAD data import into analysis software
Authors: Oakley J. , Riley C.P. , Taylor S. , Trowbridge C.W.
Published: October 2002

One of the difficulties in electromagnetic modelling has been the lack of standard CAD data to enable direct import of data into analysis software. Many solid modelling standards have been proposed over the years, but due to the many separate interests involved and differing geometrical requirements, a definitive standard has been elusive. Recently the ACIS based SAT format has gained favour and can be produced by many proprietary CAD drawing packages. This paper exemplifies a modern electromagnetic analysis tool that is able to directly import SAT format data.
3‐D eddy current computation for a transformer tank
Authors: Kanayama Hiroshi , Shioya Ryuji , Tagami Daisuke , Matsumoto Satoshi
Published: October 2002

A large scale computation of three‐dimensional eddy current problems is considered; their numbers of degrees of freedom are near one million. A parallel computing using the Hierarchical Domain Decomposition Method (HDDM) is introduced to compute large scale problems. A transformer model is considered as a numerical example, and HDDM is applicable to the model.
Quality management in Europe: a cultural perspective
Authors: Lagrosen Stefan
Published: October 2002

The purpose of the study reported in this article has been to explore and describe the influence of some national cultures on the way quality management is practised. Case studies have been carried out in the UK, Germany, France and Italy. Some differences in focus have been found. These are related to cultural theory. Hofstede’s dimensions of power distance and uncertainty avoidance are relevant for understanding the variation. The managerial implications of the differences are also discussed, notably with reference to multinational companies. Some different aspects to consider when quality initiatives are taken in the countries in question are proposed.
The Associated Reaction Rating Scale: a clinical tool to measure associated reactions in the hemiplegic upper limb
Authors: Macfarlane Anne , Turner-Stokes Lynne , De Souza Lorraine
Published: October 2002

Objective: To determine what items should be included in a clinical assessment tool developed to measure associated reactions in the hemiplegic upper limb and to assess the reliability of the resultant measure.

Design: Development through a structured consultative process using focus group methodology. Evaluation of inter- and intra-rater reliability between two independent observers.

Subjects: Nineteen consecutive hemiplegic patients admitted to Northwick Park Hospital for rehabilitation following stroke.

Methods: Focus groups were conducted in two centres, comprising physiotherapists experienced in the clinical management of brain injury. The groups identified four key characteristics related to severity of associated reactions, which became the items of the rating scale. Evaluation of inter- and intra-rater reliability was undertaken by comparison of agreement between ratings of associated reactions occurring during a single standardized task (sit-to-stand), by two senior physiotherapists in 19 subjects.

Results: There were good correlations between the two raters in total (rho 0.89 p< 0.005) and modal scores (rho 0.88 p < 0.005). Reliability testing of each item revealed moderate to very good inter-rater agreement (weighted kappa values 0.43–0.85) and good to very good intra-rater agreement (weighted kappa values 0.61–0.87). A slight tendency for one rater to score more severely than the other only reached significance for one item (excursion). Overall (modal) severity scores showed a good level of agreement (kappa 0.76–0.81) both between and within raters.

Conclusion: Items to be included in a clinical assessment tool to measure associated reactions in the hemiplegic upper limb were determined. Reliability of the resultant measure was found to be encouraging. These results however apply only to observations made during a specific standardized task (sitto-stand) and further study of sensitivity to change and reproducibility in different tasks is required before the findings can be extrapolated into routine practice.
Does four weeks of TENS and/or isometric exercise produce cumulative reduction of osteoarthritic knee pain?
Authors: Cheing Gladys LY , Hui-Chan Christina WY , Chan K M
Published: October 2002

Objective: To evaluate the cumulative effect of repeated transcutaneous electrical nerve stimulation (TENS) on chronic osteoarthritic (OA) knee pain over a four-week treatment period, comparing it to that of placebo stimulation and exercise training given alone or in combination with TENS.

Design: Sixty-two patients, aged 50–75, were stratified according to age, gender and body mass ratio before being randomly assigned to four groups.

Interventions: Patients received either (1) 60 minutes of TENS, (2) 60 minutes of placebo stimulation, (3) isometric exercise training, or (4) TENS and exercise (TENS & Ex) five days a week for four weeks.

Main outcome measures: Visual analogue scale (VAS) was used to measure knee pain intensity before and after each treatment session over a four-week period, and at the four-week follow-up session.

Results: Repeated measures ANOVA showed a significant cumulative reduction in the VAS scores across the four treatment sessions (session 1, 10, 20 and the follow-up) in the TENS group (45.9% by session 20, p < 0.001) and the placebo group (43.3% by session 20, p = 0.034). However, linear regression of the daily recordings of the VAS indicated that the slope in the TENS group (slope = -2.415, r = 0.943) was similar to the exercise group (slope = -2.625, r = 0.935), which were steeper than the other two groups. Note that the reduction of OA knee pain was maintained in the TENS group and the TENS & Ex group at the four-week follow-up session, but not in the other two groups.

Conclusions: The four treatment protocols did not show significant between-group difference over the study period. It was interesting to note that isometric exercise training of the quadriceps alone also reduced knee pain towards the end of the treatment period.
Maximal isometric muscle strength of the cervical spine in healthy volunteers
Authors: Chiu Thomas TW , Lam Tai-Hing , Hedley Anthony J
Published: October 2002

Objective: To describe the maximal isometric neck muscle strength in healthy Chinese volunteers, in six different directions, as measured by a Multi Cervical Rehabilitation Unit.

Design: A standardized cross-sectional observational study.

Setting: A university rehabilitation unit.

Subjects: Ninety-one healthy volunteers aged 20–84.

Methods: During the measurement the subject was instructed to do three consecutive steady contractions as hard as possible, with a 10-second rest in between each contraction and a 2-minute rest between different directions. The peak isometric strength for each of the six directions (‘exion, extension, lateral flexions, protraction and retraction) was calculated.

Results: No significant difference was found in muscle strength between different age groups. Isometric muscle strength in the direction of right lateral flexion was significantly greater than that to the left in men ( p = 0.030), but no difference was found in women ( p = 0.297). Isometric strength in all directions in men was 1.2–1.7 times that in women (all p < 0.028). Correlations between physical measurements (height and weight) and strength values were all insignificant in both genders.

Conclusion: Men have approximately 20–70% greater isometric neck muscle strength than women. Both men and women can maintain high levels of cervical muscle strength in six different directions up to their seventh decade. There is no significant correlation between physical measurements and isometric neck muscle strength.
The influence of local steroid injections, body weight and the length of symptoms in the treatment of painful subcalcaneal spurs with extracorporeal shock wave therapy
Authors: Melegati Gianluca , Tornese Davide , Bandi Marco , Caserta Antonello
Published: October 2002

Objective: To evaluate the effectiveness of extracorporeal shock wave therapy (ESWT) for the treatment of painful subcalcaneal spurs and evaluate whether local steroid injections, body weight and the length of symptoms can affect the clinical results.

Design: Subjects were selected through clinical examination and heel radiograms according to diagnosis of painful subcalcaneal spurs. Subjects: Sixty-four subjects were divided into two groups of treatment depending on their past history of previous local steroid injections. Interventions: Each subject received a three-session ESWT (performed weekly). A rehabilitative programme was instituted, consisting of self-assisted plantar fascia and plantar ‘exors stretching exercises.

Main outcome measures: The Mayo Clinical Scoring System (MCSS) was utilized to evaluate each subject before the treatment and at two- and ten- month follow-ups. In addition, standard radiograms were done both before the treatment and at the ten-month follow-up.

Results: Patients with no past treatment using steroids did not show any statistically significant improvement of the MCSS at the two-month follow-up. The statistical significance was obtained at the ten-month follow-up. Patients with past treatment using steroids did not show any statistically significant improvement of the MCSS at either follow-up. At the radiogram check, none of the subjects showed any modification of the heel spurs.

Conclusions: According to the results of the present study ESWT should be considered as an effective treatment for painful subcalcaneal spurs. Previous local steroid injections may negatively affect the result of ESWT.
Inhibitory effect of fruit extracts on P-glycoproteinrelated efflux carriers: an in-vitro screening
Authors: Deferme Sven , Van Gelder Jan , Augustijns Patrick
Published: October 2002

In this study, standardized food extracts were screened for their possible inhibitory effect on the P-glycoprotein (P-gp)-mediated efflux of 3H-ciclosporin A (CsA) using the in-vitro Caco-2 model. CsA is commonly used as a substrate for P-gp-related efflux carriers and is characterized by a polarity in transport, the absorptive transport being much lower than the secretory transport (polarity factor: PF ˜ 7). Of the 68 tested, nine extracts showed a decreased efflux of CsA (< 75% of the reference value) and were retained for further experiments on the bidirectional transport of CsA across Caco-2 monolayers. Results of these experiments showed that strawberry, orange, apricot and mint extract exert an inhibitory effect on intestinal P-gp-related functionality (PF < 4.2). The effect of apricot extract was also studied on the bidirectional transport of talinolol, a specific P-gp substrate; inclusion of 1 %, v/v, in the apical compartment of Caco-2 monolayers resulted in a significantly reduced polarity in the transport of talinolol (PF reference = 15.5; PF in the presence of apricot extract = 2.5). This study suggests that co-administration of fruit extracts might be a conceptually safe and useful strategy to enhance the intestinal absorption of P-gp substrates. More research is necessary to characterize the impact of this inhibition on P-gp-related efflux mechanisms in other absorption models (in-vitro and in-vivo) and to identify the compounds that are responsible for this inhibitory effect.