bluuebunny/crossref_metadata_2025 huggingface dataset:
Typification of Antithamnion nipponicum Yamada et Inagaki (Antithamnieae, Ceramioideae, Ceramiaceae, Ceramiales, Rhodophyta)
Authors: Athanasiadis Athanasios
Published: May 2009

In the absence of type specimens, a lectotype of Antithamnion nipponicum is selected here from the original illustrations of the protologue. The lectotype is in agreement with the original description and shows characters that allow unequivocal identification with an undated Yamada specimen from a syntype locality. The latter specimen is selected here as epitype. It is concluded that Antithamnion nipponicum is a heterotypic synonym of Antithamnion pectinatum, and that the correct name of the species currently passing under the name A. nipponicum should be Antithamnion hubbsii.
Cognitive Task Analysis for Developing Unmanned Aerial Vehicle Wilderness Search Support
Authors: Adams Julie A. , Humphrey Curtis M. , Goodrich Michael A. , Cooper Joseph L. , Morse Bryan S. , Engh Cameron , Rasmussen Nathan
Published: May 2009

Wilderness search and rescue (WiSAR) requires thousands of hours of search over large and complex terrains. Mini-UAVs (unmanned aerial vehicles) may dramatically improve WiSAR search efficiency. Early field trials in UAV-enabled WiSAR indicated a need to improve the human-UAV interaction, the coordination between the UAV and ground search resources, and the UAV technology. A cognitive task analysis was conducted to inform the design of the UAV technology, the associated interface, and the roles and responsibilities associated with effectively integrating the technology into the existing WiSAR response. Two cognitive task analysis techniques were employed: goal-directed task analysis and a partial cognitive work analysis that included a work domain analysis and a control task analysis. Early field trials and WiSAR search personnel informed the task analyses, which consequently informed the UAV technology design and integration. This paper (a) reviews how and why the task analyses were conducted, how the systems engineering process incorporated field trials to inform the task analyses and to guide the technology development; and (b) provides examples of how the analyses informed the resulting technology development with an eye toward providing insight into how such analysis techniques can be applied to developing UAV systems.
Interaction-Based Measures of Cognitive Systems
Authors: Cooke Nancy J. , Gorman Jamie C.
Published: May 2009

Integrating cognitive engineering into the systems engineering process requires measurement methodologies that capitalize on variability in cognition and behavior distributed across people and their environment. It is important for cognitive system integration that measures be not only reliable and valid but also unobtrusive and capable of providing predictive and diagnostic information in real time. To achieve these objectives we have developed measures of systems (in our case, small teams of humans) that are based heavily on the automated sequential analysis of communication data. These measures have been mapped to system performance, system change, system process, coordination, and situation awareness and thus are of potential value for cognitive system integration activities.
Visual Representations of Meta-Information
Authors: Bisantz Ann M. , Stone Richard T. , Pfautz Jonathan , Fouse Adam , Farry Michael , Roth Emilie , Nagy Allen L. , Thomas Gina
Published: May 2009

We conducted two studies that investigated display characteristics related to color (hue, saturation, brightness, and transparency) and contrast with a background for displaying information qualifiers (termed meta-information) such as uncertainty, age, and source quality. Level of detail (or granularity) of the meta-information and task demands were also manipulated. Participants were asked to rank and rate colored regions overlaid on different map backgrounds based on the level of meta-information the regions displayed. Results from Study 1 indicated that participants could appropriately rank and rate levels of meta-information across saturation, brightness, and transparency conditions, and results from Study 1 and Study 2 showed that the natural direction of ordering is complex and dependent on the relevance of different information to the task and the contrast of the overlay region with the background.
Modeling of Quenching and Tempering Induced Phase Transformations in Steels
Authors: Rajeev P. T. , Jin L. , Farris T. N. , Chandrasekar S.
Published: May 2009

Quenching and tempering are common processes used in the manufacture of steel components. The development of simulation tools for quenching is critical for improving process performance by minimizing component distortion and maximizing service life. While modeling of quenching has received considerable attention, there has not been much work on similar tools for tempering. This paper presents an efficient simulation tool to predict microstructure, temperature, and stress evolution, and is applicable to both quenching and tempering processes. This method takes into account the temperature dependence of material properties, transformation strains, latent heats of transformation, and transformation plasticity. Furthermore, three different micromechanical approaches are implemented and studied to simulate steel as a multiphase constitutive material: the average property model, the Voigt model, and the Reuss model. These models assume that the properties of a unit volume of material can be derived, respectively, by applying the linear rule of mixtures to the material properties of its constituent phases, by assuming that all constituent phases have the same strain field, and by assuming that all constituent phases have the same stress field. The model predicts the microstructure, stress, and distortion in the heat treated component. The simulation model is implemented within the framework of the ABAQUS finite element package by taking advantage of its advanced features to incorporate user defined material properties. Given that the material properties are strongly dependent on carbon content, the simulation method is tested using experiments with modified 4320 steel plates that were carburized on one side to amplify distortion when quenched, due to martensitic phase transformation. Distorted shapes are measured and compared to model predictions for both quenching and tempering. The detailed comparisons provide confidence in the model as well as suggestions for improvement.
An Innovative Solution for Managing Waterworks Sludge: Developing an Alum Sludge-Based Multistage Constructed Wetland System for Wastewater Treatment
Authors: Zhao Y. Q. , Babatunde A. O. , Zhao X. H.
Published: May 2009

Waterworks sludge continues to be an inescapable by-product of the potable water treatment process. Accordingly, final disposal of the sludge remains one of the most significant pressing problems for the potable water treatment industry. The possibility of reusing the sludge as a main substrate in a novel constructed wetland system was investigated in this study. Results show that significant phosphorus (P) and other pollutants removal were achieved in the system. With a mean influent 5-day biochemical oxygen demand and chemical oxygen demand levels of 392.7 and 579.8 mg/L, respectively, a removal efficiency of 90.6 % and 71.8 %, respectively, was obtained. P removal was however exceptionally high despite the high influent mean P level of 45.3 mg P/L, which is about two to three times the level of P commonly found in sewage. This is attributable to the P adsorption capacity of the alum sludge and this highlights the benefits of its reuse in the system. The paper presents and discusses the findings from a laboratory scale research, which has potential for further large scale implementation.
Konzept eines Fahrdynamikreglers für die Längs- und Querdynamik von FahrzeugenGlobal Chassis Controller Concept for Longitudinal and Lateral Vehicle Dynamics
Authors: Kober Werner , Kreutz Marlene , Angeringer Ulrich , Horn Martin
Published: May 2009

Im Rahmen des vorliegenden Beitrages werden Konzepte zur Regelung von aktiven Fahrwerks- und Antriebsstrangkomponenten am Beispiel einer Hinterachslenkung und von momentenverteilenden Antriebsstrangkomponenten vorgestellt. Ausgehend von den Ansätzen für die Regelung der Längs- und Querdynamik von Fahrzeugen wird weiters eine Gesamtsystemarchitektur eines Fahrdynamikreglers dargestellt und anhand von Messergebnissen analysiert.
The Generation of a Compact n-Heptane / Toluene Reaction Mechanism Using the Chemistry Guided Reduction (CGR) Technique
Authors: Ahmed S. S. , Mauß F. , Zeuch T.
Published: May 2009

The present study describes the compilation and validation of a compact reaction mechanism for the oxidation of n-heptane, toluene and its mixtures using the Chemistry Guided Reduction (CGR) approach. By the module-wise composition of validated reaction schemes and the successive application of chemical lumping and redundant species removal for the n-heptane oxidation model, a compact mechanism is generated for reference fuel blends of n-heptane and toluene. The new mechanism is validated for recently published OH-concentrations histories and ignition times from shock tube studies, HCCI engine experiments and flame speed measurements. The good agreement between experiment and prediction demonstrates the general applicability of the CGR method.
Investigation of the Hierarchical Structure of Kinetic Models in Ignition Problems
Authors: Bykov V. , Maas U.
Published: May 2009

In this paper a novel method for global analysis of chemical kinetic models is discussed and applied to auto ignition of high hydrocarbons. It is mainly based on the concept of decomposition of motions and follows major steps of the ILDM method. However, a very important difference of the suggested method is its ability of an explicit and global representation of the system decomposition as a standard singular perturbed system (SPS). The fact that the ILDM provides local information about the decomposition makes the ILDM quite accurate in description of the slow system dynamics, but for fast motions, which become very important in the context of ignition/extinction problems, there are up to now no reliable methods based on ILDM. Therefore, the current work is devoted to developing such a method which can be used efficiently for global analysis of the reaction mechanisms with subsequent formulation of explicit reduced models for unsteady combustion regimes like ignition processes. The suggested method is illustrated by a simple Lindemann kinetic model and then applied successfully to the auto ignition of a homogeneous n-heptane/air system.
Laser Diagnostics for the Model Development in Turbulent Premixed Flames
Authors: Dinkelacker Friedrich , Pfadler Sebastian , Leipertz Alfred
Published: May 2009

The interaction of turbulent flow and chemical processes is complex. Due to the strong turbulent fluctuations on very small scales, a direct insight into the processes has not been possible for long time. New laser diagnostics with sufficient spatial and temporal resolution allow now the answer to long discussed questions, for instance concerning the contradictory ideas of thin or thickened flame fronts in turbulent premixed combustion. More and more also numerical models allow the combined calculation of the local processes describing turbulent flow and combustion reaction. However, often unknown terms coming from the averaging procedure of the turbulence models need to have closures. Advanced application of the planar PIV measurement technique allowed the velocity field evaluation conditioned to the either unburnt or burnt gas state in turbulent premixed flames. Herewith, the direct evaluation of unclosed model terms has been possible for both RANS models as well as for models for the large-eddy simulation method. The mutual interaction of advanced laser diagnostics and numerical models is seen as one of the milestones for the development of advanced technical combustion.
CH2Cl and CHCl2 Radical Chemistry: The Formation by the Reactions CH3Cl + F and CH2Cl2 + F and The Destruction by the Reactions CH2Cl + O and CHCl2 + O
Authors: Hold M. , Hoyermann Karlheinz , Morozov I. , Zeuch T.
Published: May 2009

The primary product formation of the reactions CH2Cl + O and CHCl2 + O in the gas phase has been studied around room temperature. The coupling of a conventional discharge flow reactor via a molecular sampling system to a mass spectrometer with electron impact ionization allowed the determination of labile and stable species (set-up A). The radicals are formed by H atom abstraction in the reactions CH3Cl + F and CH2Cl2 + F. The product analysis leads to the following branching fractions relative to precursor consumption: For CH2Cl + O, the channel HCHO + Cl yields 19 % and CO + HCl + H yields 43 %, the contributions of the labile species HCO is found but not quantified. For CHCl2 + O the channel CO + HCl + Cl yields 70 %, ClCHO and the labile ClCO are detected but not quantified. The comparison to CH3 + O shows the stepwise increase of channel fractions for the CO forming routes by chlorination of the methyl radical. The rates of the reactions have been studied relative to CH3 + O and CH3OCH2 + O. Laser-induced multiphoton ionization combined with TOF mass spectrometry and molecular beam sampling from a flow reactor (set-up B) was used for the specific and sensitive detection of the CH2Cl, CHCl2, CH3, and CH3OCH2 radicals. The rate coefficient of the reactions CH2Cl + O was derived with reference to the reaction CH3OCH2 leading to k = (8.1±1.8)×1013 cm3/(mol·s) and for CHCl2 + O with reference to CH3 + O leading to k = (3.8±1.9)×1013 cm3/(mol·s). For CH3Cl + F and CH2Cl2 + F the rate coefficients have been determined with set-up A leading to k = (4.3±0.9)×1013 cm3/(mol·s) for CH3Cl + F and k = (8.4±3.8)×1013 cm3/(mol·s) for CH2Cl2 + F. Only a negligible temperature dependence in the temperature range from 250–360 K was observed for all reactions studied.
CO Formation in the 254 nm Gas Phase Photolysis of Nitrosobenzene-Oxygen Mixtures at Room Temperature
Authors: Schuler D. F. , Zabel F.
Published: May 2009

Large CO yields were detected in the gas phase photolysis of nitrosobenzene at 254 nm in the presence of O2 and N2 by long-path IR absorption in a 200 L photoreactor made of quartz. CO yields were measured at 298 K for partial pressures of O2 between 1 μbar and 1 bar and total pressures from 10 μbar to 1 bar. Depending on reaction conditions, the CO yield varied between ≤ 1 % (at p
N2 = 1 bar, p
O2 ≤ 120 μbar) and ≈ 100 % (for pO2 = 20 μbar, p
N2 = 0). The dependencies of the CO yield (i) from the O2 partial pressure in O2-N2-mixtures at a total pressure of 1 bar, (ii) from the O2 pressure in the absence of N2, and (iii) from the total pressure at constant O2 pressures show very different behaviour. They can be reproduced well by a mechanism involving vibrationally excited phenyl (C6H5*), phenylperoxy (C6H5O2*) and phenoxyl (C6H5O*) radicals where collisional relaxation of the excited radicals competes with O2 addition for C6H5* and with both unimolecular decomposition and reaction with O2 for C6H5O2* and/or C6H5O*. The measured CO yields allow to select reaction conditions where nearly exclusively either highly vibrationally excited C6H5, C6H5O2 and/or C6H5O radicals (for CO yields ≈ 1) or thermally distributed C6H5, C6H5O2 and/or C6H5O radicals (for CO yields ≤ 1 %) are formed.
Chemistry and Microphysics of Atmospheric Aerosol Surfaces: Laboratory Techniques and Applications
Authors: Zellner Reinhard , Behr P. , Seisel S. , Somnitz Holger , Treuel L.
Published: May 2009

A number of current techniques are presented by which the chemistry of interaction of selected gas phase species with atmospheric surfaces as well as the microphysical behaviour of such surfaces can be investigated. The techniques discussed include (i) the coated wall flow tube reactor, (ii) the Knudsen-cell / DRIFT spectroscopy, (iii) the surface aerosol microscopy and (iv) the molecular beam scattering technique. In each of these methods specific and robust information is deduced on the kinetics and thermodynamics of gas adsorption and reaction on surfaces. Specific examples include the adsorption of acetone on ice surfaces, the adsorption and reaction of SO2 on iron oxides, the hygroscopic and phase behaviour of binary and ternary salt solution droplets (ammonium sulphate and ammonium sulphate / dicarboxylic acids solutions) as well as on the dynamics of inelastic collisions of noble gases on super-cooled sulphuric acid surfaces. In addition we also show how quantum chemistry can be utilized to assist in interpreting absorption energies on structurally different ice surfaces. Whilst each example represents different aspects of heterogenous atmospheric interactions, they jointly represent significant progress in laboratory investigations of multi-phase atmospheric chemistry with substantial potential for application to other systems and/or problems.
Nonmetric Multidimensional Scaling Corrects for Population Structure in Association Mapping With Different Sample Types
Authors: Zhu Chengsong , Yu Jianming
Published: May 2009

Recent research has developed various promising methods to control for population structure in genomewide association mapping of complex traits, but systematic examination of how well these methods perform under different genetic scenarios is still lacking. Appropriate methods for controlling genetic relationships among individuals need to balance the concern of false positives and statistical power, which can vary for different association sample types. We used a series of simulated samples and empirical data sets from cross- and self-pollinated species to demonstrate the performance of several contemporary methods in correcting for different types of genetic relationships encountered in association analysis. We proposed a two-stage dimension determination approach for both principal component analysis and nonmetric multidimensional scaling (nMDS) to capture the major structure pattern in association mapping samples. Our results showed that by exploiting both genotypic and phenotypic information, this two-stage dimension determination approach balances the trade-off between data fit and model complexity, resulting in an effective reduction in false positive rate with minimum loss in statistical power. Further, the nMDS technique of correcting for genetic relationship proved to be a powerful complement to other existing methods. Our findings highlight the significance of appropriate application of different statistical methods for dealing with complex genetic relationships in various genomewide association studies.
Quantitative Trait Loci for Aggressive Behavior inDrosophila melanogaster
Authors: Edwards Alexis C , Mackay Trudy F C
Published: May 2009

Aggressive behavior is observed across animal taxa and is likely to be evolutionarily conserved. Although potentially advantageous, aggression can have social and health consequences in humans, and is a component of a number of psychiatric disorders. As a complex genetic trait, it is modulated by numerous quantitative trait loci (QTL) with allelic effects that can vary in direction and magnitude and that are sensitive to environmental perturbations. Assays to quantify aggressive behavior in Drosophila melanogaster have been developed, making this an ideal model system in which to dissect the genomic architecture underlying manifestation of and variation in aggressive behavior. Here, we map QTL affecting variation in aggression between two wild-type Drosophila strains. We identified a minimum of five QTL in a genomewide scan: two on chromosome 2 and three on chromosome 3. At least three and possibly all five of these QTL interact epistatically. We used deficiency complementation mapping to subdivide two linked, epistatically interacting QTL of large effect on chromosome 3 into at least six QTL, and complementation tests to mutations identified four candidate quantitative trait genes. Extensive epistasis poses a serious challenge for understanding the genetic basis of complex traits.
Rrm3 Protects the Saccharomyces cerevisiae Genome From Instability at Nascent Sites of Retrotransposition
Authors: Stamenova Radostina , Maxwell Patrick H , Kenny Alison E , Curcio M Joan
Published: May 2009

The DNA helicase Rrm3 promotes replication fork progression through >1000 discrete genomic regions and represses the cDNA-mediated mobility of the Ty1 retrotransposon. We explored the connection between DNA replication and Ty1 retromobility by investigating the basis of increased retromobility in an rrm3 mutant. Even though Ty1 cDNA levels are increased in the absence of RRM3, neither the level nor target-site specificity of cDNA integration was altered. Instead, cDNA was incorporated into the genome by a Rad52-dependent mechanism that did not involve gene conversion of genomic Ty1 sequences. In rrm3 isolates, incorporated cDNA was often present in tandem arrays. Multimeric cDNA arrays probably arise during chromosomal break repair, since their appearance was strongly correlated with the formation of gross chromosomal rearrangements. Moreover, Ty1 multimers were invariantly located on rearranged chromosomes, when present. Overexpression of a cellular RNase H, which degrades RNA in an RNA:DNA hybrid, completely suppressed the increase in Ty1 multimer formation in an rrm3 mutant. We propose that RNA:DNA hybrid regions within nascent retrotransposition events block replication in an rrm3 mutant, leading to chromosome breaks within Ty1 sequences. Multiple extragenomic Ty1 cDNA molecules are then used as donors in recombinational repair of the break before it is healed.
A note on compact-valued continuous relations on metric spaces
Authors: Ge Xun , Ge Ying
Published: May 2009

In this paper, we give a characterization of compact-valued continuous relations on metric spaces. By this characterization, we prove that for two relations
f
and
g
on a metric space
X
, the composition
gf
of
f
with
g
is compact-valued continuous if both
f
and
g
are compact-valued continuous. As a corollary of this result, for a relation
f
on a metric space
X
,
fn
is a compact-valued continuous for all
n
∈ ℕ iff
f
is a compact-valued continuous, which improves a result of H. Y. Chu and J. S. Park by omitting locally compactness of
X
.
Factoring abelian groups whose orders are products of four primes
Authors: Szabó Sándor
Published: May 2009

An affirmative answer is given to a problem on factoring finite abelian groups by subsets in a particular case.
Optimal translative packing of homothetic triangles
Authors: Januszewski Janusz
Published: May 2009

Any sequence of triangles homothetic to a fixed triangle
T
whose total area does not exceed one-half of the area of
T
can be packed translatively in
T
.
On generalized concircularly recurrent manifolds
Authors: De U. , Kalam Gazi A.
Published: May 2009

In this paper we study a new type of Riemannian manifold called generalized concircularly recurrent manifold. We obtain a necessary and sufficient condition for the constant scalar curvature of such a manifold. Next we study Ricci symmetric generalized concircularly recurrent manifold and prove that such a manifold is an Einstein manifold. Finally, we obtain a sufficient condition for a generalized concircularly recurrent manifold to be a special quasi-Einstein manifold.
Dynamic continuum model for bi-directional pedestrian flows
Authors: Huang L. , Xia Y. , Wong S. C. , Shu C.-W. , Zhang M. , Lam W. H. K.
Published: May 2009

The development of a bi-directional pedestrian-flow model based on the reactive dynamic user equilibrium principle and the look-ahead behaviour that induces a viscosity effect on movement patterns is described. The pedestrian density in this model is governed by the conservation law, in which the flow flux is implicitly dependent on the density through the stationary Hamilton-Jacobi equation that is solved using a pseudo time-marching approach. A solution algorithm is proposed and a numerical example is used to demonstrate the effectiveness of the methodology.
Thermoelastic restrained buckling of composite beams
Authors: Luu T. K. , Bradford M. A.
Published: May 2009

A model is developed for the thermoelastic restrained distortional buckling (RDB) of a steel joist in a composite beam in a steel-framed building that may take place during a compartment fire. The overall or member buckling mode must necessarily involve cross-sectional distortion, since the rigid concrete slab in the composite beam prevents the top flange of the steel joist from freely translating, rotating and twisting as would occur in conventional flexural-torsional buckling. The solution is based on a stiffness approach, with the buckling deformations being represented by a Fourier series and the Ritz method being invoked to determine an eigensolution for the critical temperature. High levels of axial restraint provided by cooler frame members can produce significant thermally induced pre-buckling compression, which can lead to early thermoelastic buckling. This significant axial force can lead to potential failure of the connections at the ends of the member, and premature buckling is advantageous as it can relieve the development of this large compressive action. The numerical solution is used to investigate the influence of the parameters affecting RDB of a composite beam in a fire.
Asset-management strategies for infrastructure embankments
Authors: Glendinning S. , Hall J. , Manning L.
Published: May 2009

Many of the earthworks that support UK transport networks are suffering because of their age and historical lack of investment in maintenance and repair. Current asset owners have to satisfy users' expectations of minimal delay in the context of ageing assets, imperfect knowledge of their condition, limited resources, increasing traffic, higher speeds, increasing environmental standards and an increasing threat from climate change. This paper summarises current asset-management practice for infrastructure embankments and illustrates how current research is providing information to assist asset owners in improving asset-management practice in the light of climate change. Additionally, it re-examines asset-management practice using a simple sustainability-based framework.
Numerical modelling of climate effects on slope stability
Authors: Rouainia M. , Davies O. , O'Brien T. , Glendinning S.
Published: May 2009

This paper reviews a method of accurately predicting changes in pore water pressure within a slope as a response to a given climate. Observations are made on the importance of correctly determining the hydraulic parameters and correctly assessing local climate conditions. The mechanical response of the slope to pore water pressure changes is modelled and it is shown how closely deformation magnitude and rate relates to climate. A diagnostic railway embankment is subjected to a simulated future climate scenario in which rain events are of higher intensity but are less persistent and average temperatures increase significantly. These climate changes are shown to reduce infiltration and increase evaporation, resulting in negative pore water pressures persisting throughout the winter months and providing improved stability.
Centrifuge modelling of climatic effects on clay embankments
Authors: Hudacsek P. , Bransby M. F. , Hallett P. D. , Bengough A. G.
Published: May 2009

This paper presents an experimental methodology using a geotechnical centrifuge and an environmental chamber to explore long-term embankment performance in light of the more severe conditions expected due to global climate change. The environmental chamber applies water and air input to control inundation and evaporation conditions at the soil surface. Example results show that a well-compacted intermediate-plasticity model embankment performs well when subjected to 19 years of alternating wet and dry periods. Finally, the paper reports an experimental methodology that will allow further model tests to be conducted to examine how different climate scenarios, soil types and compaction levels may affect long-term embankment response.
Theoretical description of embankment erosion owing to overflow
Authors: FUJISAWA K. , KOBAYASHI A. , AOYAMA S.
Published: May 2009

This paper presents a theoretical description of embankment erosion owing to overflow based on experimental results from the viewpoint of erosion. Experiments in the laboratory, where silty sand was used to make a model of an embankment, were carried out to observe and confirm the failure process of an embankment resulting from overflow. The experimental results were quite similar to those in previous studies by other researchers. Understanding the way in which a Froude-critical point migrates during overtopping failure, and then stops, is essential to modelling the failure mechanism. The migration of the Froude-critical point involves the development of erosion and the vertical drop, or headcut, that is caused when it stops. Shallow water equations and an equation governing the change in elevation of the erosional surface are used to describe the erosion of the embankment. The theory allows the profiles of an embankment during overtopping failure to be partially determined under the condition of imposed parameters. In addition, considering the Froude-critical point's migration and suspension, the time required for the complete failure of an embankment, that is the embankment break, can be estimated.
A predictive framework for liquefaction instability
Authors: ANDRADE J.E.
Published: May 2009

A predictive framework for flow liquefaction instabilities in sands is presented. A general criterion for liquefaction, based purely on the laws of physics, is presented and adapted to the important case of radial loading (e.g. triaxial, simple shear) using the Cambridge p′–q plane. Three important contributions are made in the paper. First, the instability concept is unified, and it is shown that the liquefaction criterion coincides with other instability criteria proposed previously. Second, the mechanics triggering liquefaction instabilities are highlighted using a simple instability criterion—underscoring the role of the material state and the underlying constitutive response. Third, the proposed framework is compared with experimental data from samples of sand under undrained triaxial compression, and it is shown that the proposed criterion correctly predicts the onset of liquefaction instability as a function of the sand state. Contractive samples encounter the so-called Lade's instability line, whereas dilative samples do not liquefy, but rather undergo a phase transformation. The predictive nature of the proposed procedure may open the door to better understanding, modelling, prediction and capture of catastrophic instabilities in saturated granular materials under general loading conditions.
Briefing: Researching a more resilient built environment
Authors: Bosher L.
Published: May 2009

The PRE-EMPT project is a three-year project that has set out to improve the way buildings and infrastructure in the UK are planned, designed, built, managed and retrofitted to cope with natural and manmade threats. The PRE-EMPT toolkit is being designed to help embed resilience considerations at the most appropriate stage, into a wide range of critical infrastructure and built assets. The charrettes workshops that are being conducted as part of this project are being used to encourage a wide range of stakeholders. Engineers, architects, planners, designers, and developers have to proactively consider ways in which the built environment in the UK can better withstand, and adapt to the threats of events such as floods, storms and terrorist attacks.
Performance improvements and delay in development control
Authors: Allmendinger P.
Published: May 2009

There is growing interest and concern over the impact of regulatory controls on the supply of housing in the UK. While published data indicate performance has improved considerably, the housing industry and government point to the unacceptably long time taken to secure planning permission for housing developments. This paper presents the findings of empirical research on the time taken to gain planning permission for selected recent major housing projects from a sample of local authorities in southern England. The scale of delay found was far greater than indicated by published performance data. The paper explains the disparity between published performance and experiences in relation to the discretionary nature of the British approach to planning, and highlights the perverse outcomes of performance incentives for local planning authorities.
Overdentures on implants placed in bone augmented with fresh frozen bone
Authors: Rigo Leone , Viscioni Alessandro , Franco Maurizio , Guidi Riccardo , Strohmenger Laura , Brunelli Giorgio , Carinci Francesco
Published: May 2009

Introduction In the last decade several studies have been performed to evaluate the clinical outcome of one or two stage loaded implants supporting overdentures. Aim Since fresh frozen bone (FFB) has an ever-increasing number of clinical applications and few reports are available on implants inserted into FFB, we performed a retrospective study on fixtures inserted in FFB and bearing overdentures. Methods In the period between December 2003 and December 2006, 17 patients (14 females and 3 males with a median age of about 56 years) were grafted and 60 implants inserted thereafter. A total of 17 overdentures were delivered: 8 in the mandible and 9 in the maxilla. Multiple implant systems were used: 22 Double etched, 7 SLA, 9 Anodic oxidized, and 22 CaPo4 ceramic-blasted. Implant diameter ranged from 3.25 to 4.3 mm and length from 11.5 to 16.0 mm. Implants were inserted to replace 23 incisors, 9 cuspids, 20 premolars and 8 molars. Results No implants were lost (i.e. survival rate = 100%) and no differences were detected among the studied variables. Kaplan Meier algorithm and Cox regression did not reveal any statistical differences among the studied variables also as regards the success rate. Conclusion Implants inserted FFB and bearing overdentures have a high survival rate and success rates, which are comparable to those of implants inserted in non-grafted bone. FFB bone is a reliable material for alveolar ridge augmentation. No difference was detected among removable prostheses supported by 2 or more implants.
Changes in jaw dimensions and bone density in patients with osteoporosis
Authors: Postic Srdjan
Published: May 2009

Introduction Osteopenia and osteoporosis reduce the density and mass of jaw bones. Aim The aim of this study was to present the methods of radiographic analysis in patients with osteoporosis prior to restorative treatment. Method 127 panoramic radiographs (Kodak, USA) and 39 retroalveolar radiographs (KD 58-R 30?40 mm, USA) were used for the analysis of density (DT II 05 densitometer, England) and dimensions of jaw bones with respect to segments corresponding to bone layers. Results The results of this study indicated statistically significant differences in bone density (p<0.05 and p<0.01) in patients with osteopenia. Bone density was significantly reduced (p<0.01 and p<0.001) in osteoporotic patients, when compared to controls. Significant reductions of edentulous ridges in osteoporotic patients women X=23.05 mm (kV=30.72%) and X=22.85 mm (kV=28.81%), and men X=28.83 (kV=8.55%) as well as X=25.36 (kV=11.43%), were observed. Conclusion Bone density of the upper and lower jaw is reduced in osteoporotic patients. At the very beginning of restorative prosthodontic therapy of osteoporotic patients, retroalveolar radiographs and panoramic radiographs should be obtained. Reference lines should be assigned, contours of the alveolar and edentulous ridges on radiographs should be analysed and bone density assessed.
Primary and secondary dentine thickness at the apical foramen of the mesial and distal root of the lower first permanent molar
Authors: Jovanovic-Medojevic Milica
Published: May 2009

Introduction Knowledge of the complexity of the root canal system in lower first molars and particularly the apical part of the root affects significantly the realization and success of the endodontic procedure. Aim The aim of this paper was to determine the thickness of the primary and secondary dentine around the main foramen of the mesial and distal root of the lower first permanent molar in teeth of various ages. Material and Method Fifty extracted lower first molars of both male and female patients extracted for various reasons were used in the study. All teeth were allocated to three age groups: under 25 years old (15 teeth), between 26 and 50 (20 teeth) and over 51 years old (15 teeth). After access cavity preparation, canal orifices were enlarged and root canals were explored using hand K-files #10. Using a diamond disc, the root tip was then cut off in the area of the apical foramen. Dentine thickness was determined using a complex configuration comprising of several devices which were interconnected by software. These included a polarised microscope (Leica DMLSP), a digital camera (Leica DC300) and a scanner. Results The results showed that the greatest mean thickness of the primary dentine was in the mesial root of the first lower molar in the first age group (0.177 mm), followed by the third (0.145 mm) whilst the least mean thickness was observed in the second age group (0.141 mm). In the distal root, the mean thickness of the primary dentine was in the second (0.175 mm), then the first (0.138 mm) and finally the third group (0.100 mm). The mean thickness of the secondary dentine in the mesial root was observed in the second group (1.25 mm), followed by the third (1.11 mm) whilst the least mean thickness was found in the first age group (0.95 mm). The mean thickness of the secondary dentine in the distal root was observed in the second group (1.26 mm), then the third (1.18 mm) whilst the least mean thickness was found in the first age group (0.99 mm). Conclusion The obtained results suggested that the mean thickness of the primary dentine in the mesial and distal roots was comparable. For both mesial and distal roots, the greatest mean thickness of the secondary dentine was observed in the second age group.
Risk factors for oral changes in children with epilepsy: Informative article
Authors: Jovanovic Svetlana , Gajic Ivanka , Radivojevic Vlada
Published: May 2009

Epilepsy is the most common neurological disorder in people of all ages. Based on the data regarding the prevalence of epilepsy in other countries, about 12,000 individuals under the age of 18 are estimated to suffer from active epilepsy. Children with epilepsy are a high risk group for oral diseases primarily due to psychiatric and psycho-social consequences of the primary disorder as well as the adverse effects of anti-epileptic therapy. Due to the primary disorder, children with epilepsy have reduced motivation for a number of activities, reduced mental and physical abilities, neglected social contacts, more difficult adoption of knowledge, skills, positive attitudes and behavior as well as general and oral healthcare. In children with epilepsy, there is an additional risk for oral diseases due to the adverse effects of anti-epileptic therapy such as gingival hyperplasia. Studies in other countries and in Serbia showed higher prevalence and frequency of oral diseases compared to the control group of healthy children of the same age. This paper emphasizes the need for dental educational work with children with epilepsy and their parents as well as doctors who treat the primary disorder.
Reconstruction of endodontically treated teeth after excessive loss of tooth structure: Two case reports
Authors: Stojicic Sonja , Jevremovic Danimir , Zivkovic Slavoljub
Published: May 2009

The prognosis of endodontically treated teeth depends not only on the success of the endodontic treatment, but also on the type of reconstruction. The use of fiber-reinforced resin (FRR) posts to restore endodontically treated teeth has gained popularity due to its mechanical and esthetic characteristics as well as properties of modern adhesive systems. The aim of this article was to show a clinical technique to reconstruct endodontically treated teeth with great loss of tooth structure using direct fiber-reinforced post systems and direct composite restorations. The first case was a patient with the fractured right second lower premolar. The tooth was endodontically treated and reconstructed thereafter. After the preparation of the root canal and cementation of a FRR post, particular attention was paid to the incremental and curing techniques adopted to reconstruct coronal part of the tooth. The second case was a patient with the fractured first right lower incisor. This tooth was treated in the same way. Direct composite reconstruction of endodontically treated teeth is an alternative to the prosthodontic therapy and can postpone prosthodontic therapy for a long time.
Intraoral anesthesia of the maxillary nerve with a curved needle
Authors: Lazarevic Vladan , Bankovic-Lazarevic Dusica
Published: May 2009

Introduction Anesthesia of the maxillary nerve using an extraoral approach requires the preparation of the operative field, the use of long non-standard needles, and the procedure is very painful. Therefore an intraoral approach could have great advantages. Aim The aim of this paper was to present the intraoral approach to maxillary nerve anesthesia using a curved needle, having in mind that such a procedure is less traumatic to the patient and easy to perform. Method In order to achieve maxillary nerve anesthesia, the intraoral route with a curved needle was used. A standard disposable 10 ccm syringe was used with an intramuscular needle 22G 40 mm long, which was curved with the protective cap at the 90 degrees angle, starting from the midpoint of the needle. After broadening the chick with a blunt hook, the needle was placed behind and above the maxillary tuber. The curved part of the needle was in the coronl plane and perpendicular to the axis passing through the nasion in the ventral-dorsal direction. After passing through the pterygomaxillary fissure and the preventive aspiration, 4 ml of the Lidocaini hydrochloridi with adrenalini 1:200000 was injected. Results In indicated cases the procedure was conducted in 65 patients. The desired analgesia was achieved in the region of n. maxillaris, but additional infiltrative anesthesia was necessary in the incisor region. Conclusion Anesthesia of the maxillary nerve performed as described in this case report is a reliable and simple procedure that does not require additional equipment. Unlike the extraoral approach, it is easier to perform, more precise and comfortable for the patient.
Sugar moiety has a direct influence on the secondary structure and properties of sturgeon gonadotropin
Authors: Zenkevičs Henriks , Vosekalna Ilze , Vose Vija
Published: May 2009

Sugar moiety has a direct influence on the secondary structure and properties of sturgeon gonadotropin

Sturgeon Acipenser güldenstädti Br. gonadotropic hormone (GTH) β-subunit (β-GTH) was selectively chemically deglycosylated (dg) by anhydrous hydrogen fluoride and trifluoromethane sulfonic acid. Two dgβ-GTH molecular forms retaining 35% (dgβ-GTH1) and 13% (dgβ-GTH2) of their initial carbohydrates were obtained. Investigation of the reassociated α-β hybrid dimers (recombinants) α-GTH+dgβ-GTH1 and α-GTH+dgβ-GTH2 showed that the immunoreactivity with antiserum raised against standard GTH dropped by 22.5%. Hybrid dimers were recognised by the standard GTH antibodies, which indicated that the sugar moiety was not required for the counterpart subunit interaction. Hormonal activity of the α-GTH+dgβ-GTH1 dropped twofold while the hybrid dimer α-GTH+dgβ-GTH2 completely lost its activity in in vitro tests on the frog oocytes. CD-spectra indicated considerable changes in the secondary structure of the α-GTH+dgβ-GTH2: content of the β-structures decreased fourfold, but disordered structure content increased by 52% in comparison with that of the standard α-GTH+β-GTH. However, the individual dgβ-GTH1 and dgβ-GTH2 did not show any considerable differences in their secondary structure in comparison with that of the standard subunit β-GTH. It was evident that the slightly changed secondary structure of the dgβ-GTH2 as such might not be able to produce drastic distortions in the hybrid dimer structure. A conclusion is made that the carbohydrate moiety of the β-GTH has a predominant role as a direct stabiliser of the functionally effective secondary structure of the whole sturgeon GTH heterodimeric α-β molecule.
The HauntedNomos: Activist-Artists and the (Im)possible Politics of Memory in Transitional Argentina
Authors: Bell Vikki , di Paolantonio Mario
Published: May 2009

The article considers the role that contemporary visual art and activist-artists have played in transitional Argentina, beginning from the premise that they might be understood as involved in the staging of a wide-ranging shift implied by the term transition. We have chosen three points of entry into this exploration, discussed in three sections: first, the debates around the future of the building Escuela de Mechanica de la Armada (ESMA) in Buenos Aires, which was used as a clandestine detention and extermination center during the dictatorship (1976–83); secondly, the memorial project that is El Parque de la Memoria, which is still under construction in Buenos Aires; and, thirdly, the reexhibition of visual artworks from the period of the dictatorship brought together as the group show Cuerpo y Materia (2006), curated by María Teresa Constantin as part of the public marking of the thirtieth anniversary of the military coup.

Drawing on the sociolegal perspective of Robert Cover, we consider these sites as engaging questions of memory, temporality, and membership that are both normative and, potentially, world-making in his sense. It is argued that the aesthetic, as a register that does not (wish to) articulate its demands on law in the latter's terms, nevertheless critiques and calls on law insofar as these sites (re)mark the present against (im)possible Justice. In the relations between the absent bodies of the disappeared, the desires of the “social” body and the abstract regulative body of the law, it is the “liveliness” of the haunted nomos that kindles hope that in conjuring with ghosts, people will continue to contest, to propose, and to reconsider their commitments in the pursuit of Justice.
Activism, Acceleration, and the Humanist Aporia: Indymedia Intensified in the Age of Neoliberalism
Authors: Hoofd Ingrid M.
Published: May 2009

This article suggests that the humanist aporia, which is productively at work in the Indymedia project, has become a main ingredient of technological acceleration under neoliberalism. The article draws out Indymedia's response and relation to what it will call “speed-elitism” by emancipation and by setting its tensions to work for acceleration as if it were justice. Indymedia therefore is exemplary of the present-day conundrum that humanism finds itself in, where technological mediation increasingly intensifies politics rather than annuls it. This convergence of the humanist project and technological acceleration is then logically marked by an increasing despair around how to bring about global justice, and speed-elitist underpinnings require that Indymedia be seen as left-wing promise.
Organizing Networks: Notes on Collaborative Constitution, Translation, and the Work of Organization
Authors: Zehle Soenke , Rossiter Ned
Published: May 2009

The return of political ontology and its critique of representation contributes to a retrieval of the antagonistic registers of “the political.” A corresponding interest in processes of collaborative constitution has explored alternative modalities of the (conflictual) production of (political) subjectivity. Because such efforts necessarily attend to the status of a principle of the actionable, this essay suggests that the question of a “beyond” as it relates to a politics of the actionable calls for a conceptual elaboration of “organized networks.” The essay argues that a broader analytical perspective is opened by reengaging the practice of translation.