bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Dynamic Crosslinking on Mechanical Properties of PP/EPDM Blends
Authors: Kruliš Zdeněk , Fortelný Ivan , Kovář Josef
Published: April 2003

The effect of dynamic curing of PP/EPDM blends with sulfur and thiuram disulfide systems on their mechanical properties was studied. The results were interpreted using the knowledge of the formation of phase structure in the blends during their melt mixing. It was shown, that a sufficiently slow curing reaction is necessary if a high impact strength is to be obtained. Only in such case, a fine and homogeneous dispersion of elastomer can be formed, which is the necessary condition for high impact strength of the blend. Using an inhibitor of curing in the system and a one-step method of dynamic curing leads to an increase in impact strength of blends. From the comparison of shear modulus and impact strength values, it follows that, at the stiffness, the dynamically cured blends have higher impact strength than the uncured ones.
A Simplified Method of the Preparation and Testing of Pt Microelectrodes Sealed in Glass
Authors: Weber Jan , Dousek František P.
Published: April 2003

A simplified method was used for the preparation of Pt microelectrodes sealed in glass. Electrodes were fabricated without the help of vacuum and by sealing them in soft glass capillaries. The use of SIAL and SIMAX glass produced microelectrodes with much higher and ill-defined background currents. The regular shape of voltammograms, typical for Pt, can be used as a simple test of the perfection of microelectrodes.
The Analogs of [D-Har8]Vasopressin with Di- and Trisubstituted Phenylalanine in Position 2; Synthesis and Some Biological Properties
Authors: Žertová Miroslava , Procházka Zdenko , Slaninová Jiřina , Barth Tomislav , Majer Pavel , Lebl Michal
Published: April 2003

Four analogs of vasopressin with non-coded amino acids D-homoarginine (in position 8) and 2,6-di- or 2,4,6-trisubstituted L- or D-phenylalanine (in position 2) were synthesized using the solid phase method on p-methylbenzhydrylamine resin. All the analogs were found to be uterotonic inhibitors, the most potent one in vitro and in vivo being [D-Phe(2,4,6-triMe)2,D-Har8]vasopressin with pA2 values equal to 8.1 and 7.5, respectively. All of them had negligible antidiuretic activity and were weak pressor inhibitors.
Developments, Trends and Commercial Availability of Instrumentation (Hardware and Software) in Microcomputer Based Voltammetry
Authors: Bond Alan M. , Švestka Miroslav
Published: April 2003

Voltammetry is an important electrochemical technique which is used extensively to solve problems in many areas of chemistry. Since the method is based on the use of current-potential-time curves, voltammetric instrumentation is highly suited to computer based forms of technology. In this article, an overview of existing hardware and software that have been used to facilitate improvements in computer based voltammetric instrumentation is provided. it is concluded on the basis of this survey that developments to date in the use of computer based technology have been conservative relative to those in spectroscopic forms of instrumentation. Consequently, it is postulated that a new generation of more "intelligent" voltammetric instruments would become available immediately if the full power of presently available digital hardware and software were to be implemented as has been the case with some other forms of instrumentation.
Avoiding the Braess paradox in non-cooperative networks
Authors: Korilis Yannis A. , Lazar Aurel A. , Orda Ariel
Published: April 2003

The exponential growth of computer networking demands massive upgrades in the capacity of existing networks. Traditional capacity design methodologies, developed with the single-class networking paradigm in mind, overlook the non-cooperative structure of modern networks. Consequently, such design approaches entail the danger of degraded performance when resources are added to a network, a phenomenon known as the Braess paradox.

The present paper proposes methods for adding resources efficiently to a non-cooperative network of general topology. It is shown that the paradox is avoided when resources are added across the network, rather than on a local scale, and when upgrades are focused on direct connections between the sources and destinations. The relevance of these results for modern networks is demonstrated.
Weak convergence to the coalescent in neutral population models
Authors: Möhle M.
Published: April 2003

For a large class of neutral population models the asymptotics of the ancestral structure of a sample of n individuals (or genes) is studied, if the total population size becomes large. Under certain conditions and under a well-known time-scaling, which can be expressed in terms of the coalescence probabilities, weak convergence in DE([0,∞)) to the coalescent holds. Further the convergence behaviour of the jump chain of the ancestral process is studied. The results are used to approximate probabilities which are of certain interest in applications, for example hitting probabilities.
Stochastic properties of a cumulative damage threshold crossing model
Authors: Ebrahimi Nader
Published: April 2003

In this paper we describe a model for survival functions. Under this model a system is subject to shocks governed by a Poisson process. Each shock to the system causes a random damage that grows in time. Damages accumulate additively and the system fails if the total damage exceeds a certain capacity or threshold. Various properties of this model are obtained. Sufficient conditions are derived for the failure rate (FR) order and the stochastic order to hold between the random lifetimes of two systems whose failures can be described by our proposed model.
Asymptotics of pooling design performance
Authors: Percus J. K. , Percus O. E. , Bruno W. J. , Torney D. C.
Published: April 2003

We analyse the expected performance of various group testing, or pooling, designs. The context is that of identifying characterized clones in a large collection of clones. Here we choose as performance criterion the expected number of unresolved ‘negative’ clones, and we aim to minimize this quantity. Technically, long inclusion–exclusion summations are encountered which, aside from being computationally demanding, give little inkling of the qualitative effect of parametric control on the pooling strategy. We show that readily-interpreted re-summation can be performed, leading to asymptotic forms and systematic corrections. We apply our results to randomized designs, illustrating how they might be implemented for approximating combinatorial formulae.
Computing approximate stationary distributions for discrete Markov processes with banded infinitesimal generators
Authors: Borges Carlos F. , Peters Craig S.
Published: April 2003

We develop an algorithm for computing approximations to the stationary distribution of a discrete birth-and-death process, provided that the infinitesimal generator is a banded matrix. We begin by computing stationary distributions for processes whose infinitesimal generators are Hessenberg. Our derivation in this special case is different from the classical case but it leads to the same result. We then show how to extend these ideas to processes where the infinitesimal generator is banded (or half-banded) and to quasi-birth–death processes. Finally, we give an example of the application of this method to a nearly completely decomposable Markov chain to demonstrate the general applicability of the technique.
The general coalescent with asynchronous mergers of ancestral lines
Authors: Sagitov Serik
Published: April 2003

Take a sample of individuals in the fixed-size population model with exchangeable family sizes. Follow the ancestral lines for the sampled individuals backwards in time to observe the ancestral process. We describe a class of asymptotic structures for the ancestral process via a convergence criterion. One of the basic conditions of the criterion prevents simultaneous mergers of ancestral lines. Another key condition implies that the marginal distribution of the family size is attracted by an infinitely divisible distribution. If the latter is normal the coalescent allows only for pairwise mergers (Kingman's coalescent). Otherwise multiple mergers happen with positive probability.
On the rates of convergence of Erlang's model
Authors: Fricker Christine , Robert Philippe , Tibi Danielle
Published: April 2003

The convergence to equilibrium of the renormalizedM/M/N/Nqueue is analysed. Upper bounds on the distance to equilibrium are obtained and the cut-off property for two regimes of this queue is proved. Simple probabilistic methods, such as coupling techniques and martingales, are used to obtain these results.
Limiting conditional and conditional invariant distributions for the Poisson process with negative drift
Authors: Fierro Raúl , Martínez Servet , San Martín Jaime
Published: April 2003

In this paper we study the conditional limiting behaviour for the virtual waiting time process for the queueM/D/1. We describe the family of conditional invariant distributions which are continuous and parametrized by the eigenvalues λ ∊ (0, λc], as it happens for diffusions. In this case, there is a periodic dependence of the limiting conditional distributions on the initial point and the minimal conditional invariant distribution is a mixture, according to an exponential law, of the limiting conditional distributions.
A central limit theorem for super-Brownian motion with super-Brownian immigration
Authors: Hong Wen-Ming , Li Zeng-Hu
Published: April 2003

We prove a central limit theorem for the super-Brownian motion with immigration governed by another super-Brownian. The limit theorem leads to Gaussian random fields in dimensions d ≥ 3. For d = 3 the field is spatially uniform; for d ≥ 5 its covariance is given by the potential operator of the underlying Brownian motion; and for d = 4 it involves a mixture of the two kinds of fluctuations.
Extensions of the bifurcating autoregressive model for cell lineage studies
Authors: Huggins R. M. , Basawa I. V.
Published: April 2003

The bifurcating autoregressive model has been used previously to model cell lineage data. A feature of this model is that each line of descendants from an initial cell follows an AR(1) model, and that the environmental effects on sisters are correlated. However, this model concentrates on modelling the correlations between mother and daughter cells and between sister cells, and does not explain the large correlations between more distant relatives observed by some authors. Here the model is extended, firstly by allowing lines of descent to follow an ARMA(p,q) model rather than an AR(1) model, and secondly by allowing correlations between the environmental effects of relatives more distant than sisters. The models are applied to several data sets consisting of independent cell lineage trees.
A comparison of the olfactory abilities of three species of procellariiform chicks
Authors: Cunningham Gregory B. , Van Buskirk Richard W. , Bonadonna Francesco , Weimerskirch Henri , Nevitt Gabrielle A.
Published: April 2003

Most studies investigating olfactory sensitivities in procellariiform seabirds have concentrated on adults, but little attention has been paid to how olfactory behaviours develop. We took a first step towards understanding the ontogeny of these behaviours by testing the olfactory abilities of the blue petrel Halobaena caerulea, the thin-billed prion Pachyptila belcheri, and the common diving petrel Pelecanoides urinatrix. We scored the responsiveness of chicks in a sleep-like state to puffs of odours presented near their nostrils. We tested reactions to dimethyl sulphide(DMS, a prey-related odourant) and phenyl ethyl alcohol (PEA, a novel odourant); distilled water was used as a control. Scores for blue petrel chicks were significantly greater for DMS and PEA than for control presentations, while scores for thin-billed prions were significantly greater only for PEA. Common diving petrels did not respond significantly to either odourant. These results are consistent with what is known of adult olfactory behaviours. A negative correlation between the mass of blue petrel chicks and their mean responsiveness to odours indicates that older or recently fed birds are less responsive to these stimuli.
Nutrient balancing in grasshoppers: behavioural and physiological correlates of dietary breadth
Authors: Raubenheimer D. , Simpson S. J.
Published: April 2003

We examined correlates of nutrient balancing with dietary range by comparing diet selection and ingestive, post-ingestive and performance-related responses to macronutrient imbalance in two species of grasshopper. One of the two species, Locusta migratoria (the African migratory locust), is a specialist grass-feeder, while the other, Schistocerca gregaria (the desert locust), is a generalist herbivore that includes both grasses and forbs in its diet. In ad libitum conditions, both species composed a balanced intake of the two macronutrients protein and carbohydrate from nutritionally complementary synthetic foods, but the composition of the selected diet differed, with the generalist selecting more protein, but not carbohydrate, than the grass-specialist. The grass-specialist, by contrast,retained ingested nitrogen more efficiently on the ad libitum diets. When confined to nutritionally imbalanced foods, both species regulated ingestion in such a way as to mitigate excesses as well as deficits of the two nutrients. The responses were, however, distinct in the two species, with the generalist feeder ingesting greater excesses of protein than the specialist. The species also differed in their post-ingestive responses to ingested excesses of nutrient, with the generalist but not the specialist using protein-derived carbon as an energy source when fed carbohydrate-deficient foods. The generalist also retained a higher level of body protein when confined to protein-deficient diets. The data suggested one functional reason why the generalist species selected a diet with higher protein content in the ad libitum treatment because, when confined to the nutritionally imbalanced foods, development rate peaked on higher protein foods for the generalist compared with the specialist. Many aspects of these data agree with the prediction that generalist-feeding animals should show greater behavioural and physiological flexibility in their responses to nutrient imbalance than do specialists.
Kinematics of 90° running turns in wild mice
Authors: Walter Rebecca M.
Published: April 2003

Turning is a requirement for locomotion on the variable terrain that most terrestrial animals inhabit and is a deciding factor in many predator–prey interactions. Despite this, the kinematics and mechanics of quadrupedal turns are not well understood. To gain insight to the turning kinematics of small quadrupedal mammals, six adult wild mice were videotaped at 250 Hz from below as they performed 90° running turns. Four markers placed along the sagittal axis were digitized to allow observation of lateral bending and body rotation throughout the turn. Ground contact periods of the fore- and hindlimbs were also noted for each frame. During turning, mice increased their ground contact time, but did not change their stride frequency relative to straight running at maximum speed. Postcranial body rotation preceded deflection in heading, and did not occur in one continuous motion,but rather in bouts of 15–53°. These bouts were synchronized with the stride cycle, such that the majority of rotation occurred during the second half of forelimb support and the first half of hindlimb support. In this phase of the stride cycle, the trunk was sagittally flexed and rotational inertia was 65% of that during maximal extension. By synchronizing body rotation with this portion of the stride cycle, mice can achieve a given angular acceleration with much lower applied torque. Compared with humans running along curved trajectories, mice maintained relatively higher speeds at proportionately smaller radii. A possible explanation for this difference lies in the more crouched limb posture of mice, which increases the mechanical advantage for horizontal ground force production. The occurrence of body rotation prior to deflection in heading may facilitate acceleration in the new direction by making use of the relatively greater force production inherent in the parasagittal limb posture of mice.
Visteon's Sterling Plant Uses Simulation-Based Decision Support in Training, Operations, and Planning
Authors: Pfeil George , Holcomb Ron , Muir Charles T. , Taj Shahram
Published: April 2003

Visteon's Sterling plant uses a strategic decision support system (DSS) that integrates plant-floor information systems and simulation for three related, mutually reinforcing purposes: productivity training, productivity improvement in operations, and design of new operations. A self-directed team of the front-axle production line at the plant used the DSS to increase production of front axles for Ford Expeditions, Lincoln Navigators, and F-series trucks. Improving the productivity of this production line was important to the plant, the customers, and company profitability as the US market for high-profit margin 4 X 4 trucks and sport utility vehicles exploded. As a result of the new system, productivity improved by more than 30 percent. The plant produced an “extra” 144,496 front axles between January 1997 and July 1998. The DSS was also instrumental in Visteon avoiding a $10 million modification on the line that would have been inefficient. Visteon used the DSS in designing a new line with higher productivity and $5.5 million cost savings.
Extended-Enterprise Supply-Chain Management at IBM Personal Systems Group and Other Divisions
Authors: Lin Grace , Ettl Markus , Buckley Steve , Bagchi Sugato , Yao David D. , Naccarato Bret L. , Allan Rob , Kim Kerry , Koenig Lisa
Published: April 2003

In 1994, IBM began to reengineer its global supply chain. It wanted to achieve quick responsiveness to customers with minimal inventory. To support this effort, we developed an extended-enterprise supply-chain analysis tool, the Asset Management Tool (AMT). AMT integrates graphical process modeling, analytical performance optimization, simulation, activity-based costing, and enterprise database connectivity into a system that allows quantitative analysis of extended supply chains. IBM has used AMT to study such issues as inventory budgets, turnover objectives, customer-service targets, and new-product introductions. We have implemented it at a number of IBM business units and their channel partners. AMT benefits include over $750 million in material costs and price-protection expenses saved in 1998.
Spicer Off-Highway Products Division-Brugge Improves its Lead-Time and Scheduling Performance
Authors: Vandaele Nico J. , Lambrecht Marc R. , De Schuyter Nicolas , Cremmery Rony
Published: April 2003

Spicer Off-Highway Products Division (a division of Dana Corporation) asked us to develop OR tools to improve the due date performance and to shorten the manufacturing lead time of its powershift transmission plant in Brugge, Belgium. We modeled the manufacturing system as a queueing model and used the model to analyze and evaluate improvement schemes (layout changes, product-mix decisions, lot-sizing decisions, and lead-time estimations). Next, we developed a finite scheduler to improve the detailed scheduling of the shop. Our modeling effort contributed to the successful combination of analysis, planning, and detailed scheduling. The plant increased productivity by 27.3 percentage points, decreased manufacturing lead times by a factor of two to three, increased its workforce by 41 percent, and decreased its operating costs. The division is now profitable.
A World of Abundance
Authors: McDonough William , Braungart Michael
Published: April 2003

Industry and the environment appear to be at odds because current methods of production, extraction, and disposal are destructive to the natural world. Conventional responses, such as eco-efficiency, focus on doing more with less, restricting industry, and curtailing growth. We view the conflict between industry and the environment as a design problem. Instead of simply reducing industry's negative effects, we suggest companies redesign products and processes for healthy, long-term prosperity. We present a new paradigm for industry, eco-effectiveness; three new design principles: waste equals food, use current solar income, and respect diversity; new decision criteria that integrate ecology, economy, and equity; and beginning steps businesses can take towards a world of abundance, rather than one of limits and constraints.
An Assessment of Design-for-Environment Practices in Leading US Electronics Firms
Authors: Lenox Michael , King Andrew , Ehrenfeld John
Published: April 2003

A growing number of managers believe that addressing environmental impacts in product-design decisions has tangible advantages to firms. Yet many firms struggle to diffuse design-for-environment (DfE) practices across their product-development teams. Four leading electronics firms' attempts to adopt DfE suggest that the establishment of highly interconnected, internal information networks may be a robust diffusion strategy. Technically competent centers acting as clearinghouses of companywide information relevant to environmental design and coordinated with specialists on individual product-design teams seem to be an effective organizational structure for diffusing DfE. Internal information networks reduce the cost to designers of assessing environmental costs and benefits and thus lower the motivational barriers of product managers. Environmental design tools may be a component of successful DfE practice but do not seem to be sufficient in themselves. The complexity of environmental issues requires an approach that continually generates new information. Dense information networks allow pockets of expertise to form in response to ever-changing needs.
Heery International's Spreadsheet Optimization Model for Assigning Managers to Construction Projects
Authors: LeBlanc Larry J. , Randels Dale , Swann T. K.
Published: April 2003

When assigning managers to construction projects, Heery International tries to minimize the total cost of the assignments while maintaining a balanced workload for different managers. We developed and implemented an Excel spreadsheet optimization model for problems with up to 114 projects. As time passes, new projects arise, old projects terminate, and occasionally new managers join the team, and existing ones resign or transfer out. Because the model is in a spreadsheet environment, Heery can easily add or remove projects and managers from the model. As a result of our model, Heery has managed its projects without replacing a manager who resigned and has reduced travel costs, because the model assigns managers to projects that are closer to their homes than previously.
Inferring the Characteristics of an Arsonist from Crime Scene Actions: A Case Study in Offender Profiling
Authors: Santtila Pekka , Häkkänen Helinä , Fritzon Katarina
Published: April 2003

The purpose of the present case study was to apply psychological models of offender behaviour in providing assistance to an ongoing police investigation of a series of arsons. After a general description of the series, the analysis of the crime scene and spatial behaviour of the offender were described followed by predictions concerning likely background characteristics and home location. The accuracy of these predictions was evaluated against information concerning the suspect in the case. The characteristics predicted, based on the findings of Canter and Fritzon (1998), were in good accordance with the actual characteristics of the suspect in the case. Also, it was possible to provide fairly good estimates of the home location of the suspect based on the crime locations. There was a difference between those predicted characteristics that were based strictly on the Canter and Fritzon model and the spatial predictions which were more accurate compared to predictions based on ‘common sense’.
Acquisition of Marksmanship and Gun Handling Skills through Basic Law Enforcement Training in an American Police Department
Authors: Charles Michael T. , Copay Anne G.
Published: April 2003

In order to evaluate the marksmanship skills and gun handling skills that could be learned through the basic law enforcement firearms course, the skills of 216 inexperienced shooters (185 men and 31 women) were measured before and after the basic law enforcement firearms course. The marksmanship test consisted in shooting 14 rounds from a distance of 15 yards. The gun handling test consisted in loading the handgun, unloading the handgun, and clearing a type 3 malfunction. The marksmanship scores significantly improved after the firearms course (from 43.46 to 106.86 points) but the women's scores were significantly lower than the men's scores both before and after the course. Recruits significantly reduced the time needed to load the weapon (from 27.17 to 9.12 seconds), to unload the weapon (from 15.48 to 3.84 seconds), and to clear the malfunction (from 30.13 to 11.05 seconds) but women took more time than men to clear the malfunction. The content of the basic firearms course is presented, the validity of law enforcement firearms training is discussed, and recommendations are made in order to improve training.
Does the Police Academy Change Your Life? A Longitudinal Study of Changes in Socialising Behaviour of Police Recruits
Authors: Obst Patricia L. , Davey Jeremy D.
Published: April 2003

The current study tracks the social behaviour of new police recruits from pre-Academy, after six months' Academy training, through to one year into police training ( N = 177). The results showed that recruits socialise and drink more with colleagues after entering the Academy than they did pre-Academy. The way recruits drank also changed during training with a tendency towards heavier drinking sessions. Further results indicated that recruits did feel some pressure to drink to fit in and be one of the crowd. These findings, based on a longitudinal methodology suggest that the enculturation process encouraging recruits to socialise and drink with peers begins early in the training process. The findings are discussed in terms of intervention.
The Police Informer/Handler Relationship: Is it Really Unique?
Authors: Billingsley Roger
Published: April 2003

The use of informers by the police service in the UK has been the subject of recent research, even though the police service in this country has been protective towards this particular investigative method. It has been revealed from this research that there is a common assumption that the use of informers is quite unique among police relationships. This paper examines whether in fact the relationship between an informer and the police is really that unique, or whether it is the secrecy which surrounds it that provokes such an assumption.

The paper relies heavily on a comparison with other relationships, starting with typical professional partnerships, then examining other police relationships. The factors which emerge from these relationships have been compared to police/informer relationships to determine how dissimilar they are. The paper suggests there are in fact many similarities between a police/ informer relationship and other professional partnerships, and concludes that it is probably the secrecy which the police have maintained that has created the assumption that the relationship is unique.

It is suggested by the author that if the police/informer relationship became more transparent and accountable then this may lead to law enforcement agencies being less able to hide behind the veil of secrecy, which may help the concept of openness within the criminal justice system.
Long‐term survival in Stuve‐Wiedemann syndrome: A neuro‐myo‐skeletal disorder with manifestations of dysautonomia
Authors: Di Rocco M. , Stella G. , Bruno C. , Doria Lamba L. , Bado M. , Superti‐Furga A.
Published: April 2003

Stuve‐Wiedemann syndrome (SWS) is a multiple congenital anomalies syndrome mostly considered to have an early lethality. Only few patients have been reported with long survival; therefore, the clinical phenotype with age has not yet been clearly characterized. We report on two patients with SWS aged 12 and 3 years who have both the osteodysplastic symptoms of the entity as well as autonomic nervous system symptoms resembling familial dysautonomia: lack of corneal reflex and neuropathic keratitis, absence of fungiform papillae, ulcerations of the tongue, paradoxical sweating at low temperature, patellar hyporeflexia, and progressive scoliosis. The clinical and radiological similarities between patients with SWS and patients with Schwartz‐Jampel syndrome have led to the suggestion that these two syndromes are a single entity. SWS and Schwartz‐Jampel syndrome type II are now indeed considered to be identical, but the radiographic phenotype of SWS long survivors such as the presently reported patients justifies the distinction between SWS and the classical type of Schwartz‐Jampel syndrome. An increased number of lipid droplets in muscle fibers and decreased muscle mitochondrial enzyme activities have been found in one patient, confirming a previously reported association between SWS and respiratory chain abnormalities. © 2003 Wiley‐Liss, Inc.
Facial approximation: An evaluation of mouth‐width determination
Authors: Stephan Carl N.
Published: April 2003

Facial approximation techniques rely on the prediction of soft tissues from the skull, yet few prediction methods have been scientifically evaluated, despite being frequently used in the past. This study tests several published and commonly used methods for determining mouth width from the skull. The methods tested are: 1) that mouth width is equal to the distance between the pupils; 2) that mouth width is equal to the distance between the medial borders of the iris; and 3) that mouth width is equal to the distance between the most lateral junctions of the canines and the first premolars. The study primarily examines living Australian European and Central/South East Asian participants (of both sexes) using photogrammetric methods. The results of this study indicate that methods 1 and 3 are highly inaccurate. Method 1 overestimated mouth width, on average, by ∼11 mm (SD, 4 mm), while method 3 underestimated mouth width by ∼13 mm (SD, 3 mm). Method 2 was the most accurate of the methods evaluated, but on average underrepresented mouth width by ∼2 mm (SD, 4 mm). All three methods produced mouth‐width predictions that, in general, were statistically different from actual mouth widths (P < 0.05). A new guideline, describing mouth width as canine width plus 57% of the cumulative distance between the lateral canine borders and the pupil centers on each side was found not to differ at statistically significant levels from actual mouth widths (P > 0.05). On average, this guideline did not under/overestimate actual mouth width, with the difference between them being 0 mm (SD, 3 mm). The increased accuracy of this new guideline in comparison to others suggests that it is the most appropriate for facial approximation. However, it should be further tested using independent samples. The finding that commonly used mouth‐width prediction guidelines are not accurate suggests that many facial approximations previously made have incorrect mouth widths. This could reduce the recognition of these facial approximations and may, especially if other guidelines are inaccurate, render the facial approximations unrecognizable as their respective target individual (individual to whom the skull belongs). Am J Phys Anthropol 121:000–000, 2003. © 2003 Wiley‐Liss, Inc.
Characterization of aluminum–organic‐stabilized platinum–colloid networks with electron and photon spectroscopies
Authors: Beuermann L. , Maus‐Friedrichs W. , Krischok S. , Kempter V. , Bucher S. , Modrow H. , Hormes J. , Waldöfner N. , Bönnemann H.
Published: April 2003

We have measured and interpreted the ultraviolet (HeI) and X‐ray photoelectron spectra and the metastable impact electron spectra (MIES) from aluminum–organic‐stabilized platinum–colloids and colloid networks, deposited on silicon substrates and characterized by X‐ray photoelectron spectroscopy, scanning Auger electron microscopy and transmission electron microscopy. MIES, in particular, gives information on the electronic structure of the spacer molecules interconnecting the colloids.

In addition, changes in the electronic structure of the platinum clusters that are induced by different spacer molecules were identified by means of X‐ray absorption near‐edge structure measurements at the platinum LIII‐edge of these materials. This combination of techniques was also employed to follow the chemical changes that occur upon heating of the network in situ. It turns out that the thermal decomposition of the network is driven by the disintegration of the spacer molecules. Moreover, less sintering of the colloidal particles occurs in the networked systems than in unconnected particles. Most of the networked platinum–particles are still present in their original shape even after the destruction of spacer molecules. This observation could be linked to the encapsulation of these platinum particles into an (AlO) protecting shell. Copyright © 2003 John Wiley & Sons, Ltd.
An improved procedure for syntheses of silyl derivatives of the cubeoctameric silicate anion
Authors: Hasegawa Isao , Ino Kadzuko , Ohnishi Haruka
Published: April 2003

The reaction of the Si8O208− silicate anion with X(CH3)2SiCl (XH or CH3) has been studied to develop a cost‐effective procedure for synthesizing Si8O20[Si(CH3)2X]8 in high yield. Use of hexane as solvent and adjustment of the reaction temperature to ca 20 °C were found to be effective in promoting the reaction, by which Si8O20[Si(CH3)2X]8 could be produced in good yield employing 24 mol of X(CH3)2SiCl per mole of Si8O208−. It was also demonstrated that the yield of Si8O20[Si(CH3)2X]8 depends on the amount of solvent, suggesting that the amount is an important factor when scaling up the reaction to produce a large quantity of Si8O20[Si(CH3)2X]8. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of copper adsorption on the mechanical properties of chitosan beads
Authors: Mitani Tomoyo , Kawakami Takashi , Morishita Makoto , Adachi Yasumasa , Ishii Hiroshi
Published: April 2003

The effect of copper adsorption on the mechanical properties of chitosan beads was investigated by measurement of creep modulus with a dynamic mechanical analyzer. Creep modulus changed drastically at a critical copper adsorption amount of 0.4 mol/mol of glucosamine unit. Creep modulus increased with increasing amount of copper up to 0.4 mol/mol, but decreased steeply as the amount of copper increased beyond 0.4 mol/mol. The variation in creep modulus with copper adsorption is discussed in terms of two models that describe the binding mode of transition metal to chitosan; the bridge model and the pendant model. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2988–2991, 2003
High mobility group box chromosomal protein 1 plays a role in the pathogenesis of rheumatoid arthritis as a novel cytokine
Authors: Taniguchi Noboru , Kawahara Ko‐Ichi , Yone Kazunori , Hashiguchi Teruto , Yamakuchi Munekazu , Goto Masamichi , Inoue Keiichi , Yamada Shingo , Ijiri Kosei , Matsunaga Shunji , Nakajima Toshihiro , Komiya Setsuro , Maruyama Ikuro
Published: April 2003

Objective

High mobility group box chromosomal protein 1 (HMGB‐1), a nuclear DNA binding protein, was recently rediscovered as a new proinflammatory cytokine. The purpose of this study was to demonstrate HMGB‐1 expression in vivo and to identify the role of HMGB‐1 in the pathogenesis of rheumatoid arthritis (RA).

Methods

HMGB‐1 concentrations in synovial fluid (SF) and serum from RA and osteoarthritis (OA) patients were measured by immunoblot analysis. The protein's specific receptor, receptor for advanced glycation end products (RAGE), was examined in SF macrophages (SFMs). We measured levels of proinflammatory cytokines released by SFMs treated with HMGB‐1 via enzyme‐linked immunosorbent assay and used soluble RAGE (sRAGE) to block the release of tumor necrosis factor α (TNFα). Immunohistochemical analysis and immunofluorescence assay were employed to examine localization of HMGB‐1 in RA synovium and its translocation in SFMs after TNFα stimulation.

Results

HMGB‐1 concentrations were significantly higher in SF of RA patients than in that of OA patients. SFMs expressed RAGE and released TNFα, interleukin‐1β (IL‐1β), and IL‐6 upon stimulation with HMGB‐1. HMGB‐1 was found in CD68‐positive cells of RA synovium, and TNFα stimulation translocated HMGB‐1 from the nucleus to the cytosol in SFMs. Blockade by sRAGE inhibited the release of TNFα from SFMs.

Conclusion

HMGB‐1 was more strongly expressed in SF of RA patients than in that of OA patients, inducing the release of proinflammatory cytokines from SFMs. HMGB‐1 plays a pivotal role in the pathogenesis of RA and may be an original target of therapy as a novel cytokine.
T cells regulate the expression of matrix metalloproteinase in human osteoblasts via a dual mitogen‐activated protein kinase mechanism
Authors: Rifas Leonard , Arackal Sophia
Published: April 2003

Objective

To investigate the role of T cell induction of matrix metalloproteinase 13 (MMP‐13) production by human osteoblasts in order to better understand the process of bone loss in rheumatoid arthritis (RA).

Methods

Activated T cell–conditioned medium (ACTTCM) was used to mimic the physiologic conditions of inflammation. MMP‐13 production by human osteoblasts was assessed using a specific enzyme‐linked immunosorbent assay. Specific inhibitors of the p38 mitogen‐activated protein (MAP) kinase and the extracellular signal–regulated kinase 1/2 (ERK‐1/2) MAP kinase signaling pathways were used to assess their roles in T cell–mediated MMP‐13 production. Finally, recombinant cytokines representative of the major components in ACTTCM were assessed for their ability to induce MMP‐13.

Results

ACTTCM powerfully induced MMP‐13 in human osteoblasts. Inhibition of p38 activity abolished, while inhibition of ERK‐1/2 activity enhanced, MMP‐13 production. We next investigated physiologic levels of the T cell cytokines tumor necrosis factor α (TNFα), transforming growth factor β (TGFβ), interferon‐γ (IFNγ), and interleukin‐17 (IL‐17) for their roles in MMP‐13 induction. Although individual cytokines had no significant effect, the combination of TNFα, TGFβ, IFNγ, and IL‐17 resulted in a dramatic p38‐dependent induction of MMP‐13 identical to that produced by ACTTCM.

Conclusion

These studies demonstrate for the first time that human osteoblasts produce MMP‐13. The results also show that under conditions of chronic inflammation, multiple T cell cytokines synergize to induce high levels of MMP‐13 via a mechanism that is dependent on activated p38 MAP kinase and is suppressed by activated ERK‐1/2. Selective inhibition of p38 activity may offer a target for pharmacologic inhibition of bone loss in RA.
Magnetic resonance imaging examinations of the spine in patients with ankylosing spondylitis, before and after successful therapy with infliximab: Evaluation of a new scoring system
Authors: Braun J. , Baraliakos X. , Golder W. , Brandt J. , Rudwaleit M. , Listing J. , Bollow M. , Sieper J. , van der Heijde D.
Published: April 2003

Objective

To evaluate a magnetic resonance imaging (MRI) scoring system for the assessment of spinal inflammation in patients with ankylosing spondylitis (AS) who participated in a randomized, placebo‐controlled trial of infliximab, and to examine whether infliximab is also effective for the reduction of MRI‐proven spinal inflammation.

Methods

Twenty patients with AS (9 women and 11 men, mean age 40.9 years) were examined at baseline and after 3 months. Nine patients had received infusions of infliximab (5 mg/kg body weight) at weeks 0, 2, and 6, and 11 patients had received placebo. Three MRI sequences and 2 scoring systems were used. Chronic lesions were evaluated by T1‐weighted turbo spin‐echo (TSE) sequences and were assigned a chronicity score. Active lesions were evaluated either by repetition of T1‐weighted TSE sequences after infusion of gadolinium–diethylenetriaminepentaacetic acid (Gd‐DTPA) or by short tau inversion recovery (STIR) sequences, and were assigned an activity score. The 40 images were evaluated twice by 2 readers who were blinded to the names of the patients and the dates of the examinations, and were analyzed in relation to the clinical results.

Results

Active spinal lesions were detected in 15 of 20 patients (75%); the frequency as determined by STIR was equal in the 2 groups. At baseline, the total MRI scores determined using Gd‐DTPA, STIR, and T1 were 112.5, 156, and 253.5, respectively. The interrater variance and intrarater variance were, respectively, 6.4 and 7.7 for the active lesion score as determined by Gd‐DTPA, 15.7 and 5.3 for the active lesion score as determined by STIR sequence, and 167.3 and 75.5 for the chronic lesion score as determined by T1 sequence. Based on the means of the scores assigned by the 2 readers, the active lesion score as determined by Gd‐DTPA improved by 40% in the infliximab group compared with 6% in the placebo group, the active lesion score as determined by STIR improved by 60% in the infliximab group but deteriorated by 21% in the placebo group, and the chronic lesion score as determined by T1 improved by 7% in the infliximab group but worsened by 35% in the placebo group. Five patients in the infliximab group and 2 in the placebo group were clinical responders. The acute MRI changes correlated with clinical improvement as assessed by the Bath Ankylosing Spondylitis Disease Activity Index.

Conclusion

This novel MRI scoring system performed well in assessing acute inflammation by using STIR and post–Gd‐DTPA sequences. In correlation with clinical improvement in patients with active AS who were treated with infliximab, significant regression of spinal inflammation was shown by using the MRI activity scores.
Enhanced susceptibility to end‐organ disease in the lupus‐facilitating NZW mouse strain
Authors: Xie Chun , Zhou Xin J. , Liu Xuebin , Mohan Chandra
Published: April 2003

Objective

Although the NZW mouse strain is phenotypically normal, fulminant lupus glomerulonephritis (GN) develops when NZW mice are bred to several other strains, such as NZB, BXSB, B6.Sle1, and B6.Yaa. Based on the observation that aging NZW mice exhibit histologic evidence of GN, we sought to test our hypothesis that NZW mice may be more susceptible to immune‐mediated renal damage.

Methods

NZW mice, as well as C57BL/6 (B6) and BALB/c control mice, were challenged with rabbit anti–glomerular basement membrane nephrotoxic sera (NTS), to induce renal disease. The different mouse strains were monitored for the degree of clinical disease, renal pathology, chemokine profiles, and cellular infiltrates.

Results

Although the NZW and control strains showed similar glomerular deposits of rabbit Ig and exhibited similar levels of anti‐rabbit xenogeneic immune response, the NZW mice had significantly worse pathologic changes and disease. Compared with the control strains, the NTS‐injected NZW mice demonstrated significantly increased proteinuria, elevated blood urea nitrogen levels, more severe histologic GN and tubulointerstitial nephritis, increased glomerular crescent formation with macrophage and neutrophil infiltrates, elevated expression of CC and CXC chemokines (monocyte chemoattractant protein 1, RANTES, KC), and significantly accelerated mortality. Importantly, these changes occurred within a few days after NTS administration. Finally, (B6 × NZW)F1 mice were as susceptible as the NZW parents, which indicates dominant NZW contributions.

Conclusion

Collectively, these findings support the notion that a lupus‐facilitating genome may contribute to disease susceptibility by modulating the degree of immune‐mediated end‐organ damage. The availability of B6‐based congenic strains bearing individual NZW‐derived lupus susceptibility loci will permit future genetic dissection of end‐organ susceptibility in murine lupus.
Matrix fixed‐charge density as determined by magnetic resonance microscopy of bioreactor‐derived hyaline cartilage correlates with biochemical and biomechanical properties
Authors: Chen Chih‐Tung , Fishbein Kenneth W. , Torzilli Peter A. , Hilger Amy , Spencer Richard G. S. , Horton Walter E.
Published: April 2003

Objective

To use noninvasive magnetic resonance imaging (MRI), biochemical analyses, and mechanical testing of engineered neocartilage grown in a hollow‐ fiber bioreactor (HFBR) to establish tissue properties, and to test the hypothesis that MRI can be used to monitor biochemical and biomechanical properties of neocartilage.

Methods

Chondrocytes from day 16 embryonic chick sterna were inoculated into an HFBR and maintained for up to 4 weeks with and without exposure to chondroitinase ABC. The fixed‐charge density (FCD) of the cartilage was determined using the MRI gadolinium exclusion method. The sulfated glycosaminoglycan (S‐GAG), hydroxyproline, and DNA contents were determined using biochemical procedures, while dynamic and equilibrium moduli were determined from mechanical indentation tests.

Results

S‐GAG content, tissue cross‐sectional area, and equilibrium modulus of the neocartilage increased with development time. There was a gradient of S‐GAG content across the length of control neocartilage at the 4‐week time point, with higher values being found toward the inflow region. Exposure to chondroitinase ABC resulted in a decrease in tissue area, negative FCD, proteoglycan content, and equilibrium and dynamic moduli. The treated bioreactors displayed a lengthwise variation in S‐GAG content, with higher values toward the outflow end. Linear correlations were established among FCD, proteoglycan content, and biomechanical properties.

Conclusion

HFBR‐derived neocartilage showed regional variation in S‐GAG content under control conditions, and in the decrease of S‐GAG in response to enzyme treatment. In addition, the results support the hypothesis that tissue parameters derived from MRI can be used to noninvasively monitor focal neocartilage formation and biochemical and biomechanical properties.
Radiographic damage associated with low bone mineral density and vertebral deformities in rheumatoid arthritis: The Oslo‐Truro‐Amsterdam (OSTRA) collaborative study
Authors: Lodder Mariette C. , Haugeberg Glenn , Lems Willem F. , Uhlig Till , Orstavik Ragnhild E. , Kostense Piet J. , Dijkmans Ben A. C. , Kvien Tore K. , Woolf Anthony D.
Published: April 2003

Objective

To examine variables associated with bone mineral density (BMD) and vertebral deformities in women with rheumatoid arthritis (RA) from 3 northwest European countries.

Methods

Female patients were recruited from rheumatology clinics in Oslo, Norway; Truro, UK; and Amsterdam, The Netherlands (150 total, 50 per center, age 50–70 years, disease duration ≥5 years). Demographic and clinical data were collected and BMD was measured by means of dual energy x‐ray absorptiometry. Associations between demographic and clinical measures on the one hand and BMD and vertebral deformities on the other were investigated by single and multiple regression analyses.

Results

Body mass index (BMI), medication use, RA damage measures, and BMD differed significantly between the 3 centers. Overall, Norwegian patients had the lowest BMI, used more corticosteroids and antiosteoporotic drugs, had lower joint damage measured by Larsen score, and lower BMD at both spine and hip. High age, low BMI, and high cumulative dose of corticosteroids (last 2 years) are related to low BMD. A high Larsen score was associated with low BMD at the hip. Larsen score was the independent determinant of vertebral deformities after correction for center, age, BMI, and BMD.

Conclusion

Data from 3 countries on BMD and vertebral deformities in female patients aged 50–70 years with longstanding RA are presented, demonstrating an association between radiographic RA damage and low BMD and between radiographic RA damage and vertebral deformities.