bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of Secondary Organic Aerosols Through Photooxidation of Isoprene
Authors: Claeys Magda , Graham Bim , Vas Gyorgy , Wang Wu , Vermeylen Reinhilde , Pashynska Vlada , Cafmeyer Jan , Guyon Pascal , Andreae Meinrat O. , Artaxo Paulo , Maenhaut Willy
Published: February 2004

Detailed organic analysis of natural aerosols from the Amazonian rain forest showed considerable quantities of previously unobserved polar organic compounds, which were identified as a mixture of two diastereoisomeric 2-methyltetrols: 2-methylthreitol and 2-methylerythritol. These polyols, which have the isoprene skeleton, can be explained by OH radical–initiated photooxidation of isoprene. They have low vapor pressure, allowing them to condense onto preexisting particles. It is estimated that photooxidation of isoprene results in an annual global production of about 2 teragrams of the polyols, a substantial fraction of the Intergovernmental Panel on Climate Change estimate of between 8 and 40 teragrams per year of secondary organic aerosol from biogenic sources.
Recruitment and Spreading of the
C. elegans
Dosage Compensation Complex Along X Chromosomes
Authors: Csankovszki Györgyi , McDonel Patrick , Meyer Barbara J.
Published: February 2004

To achieve X-chromosome dosage compensation, organisms must distinguish X chromosomes from autosomes. We identified multiple, cis-acting regions that recruit the
Caenorhabditis elegans
dosage compensation complex (DCC) through a search for regions of X that bind the complex when detached from X. The DCC normally assembles along the entire X chromosome, but not all detached regions recruit the complex, despite having genes known to be dosage compensated on the native X. Thus, the DCC binds first to recruitment sites, then spreads to neighboring X regions to accomplish chromosome-wide gene repression. From a large chromosomal domain, we defined a 793–base pair fragment that functions in vivo as an X-recognition element to recruit the DCC.
Placebo-Induced Changes in fMRI in the Anticipation and Experience of Pain
Authors: Wager Tor D. , Rilling James K. , Smith Edward E. , Sokolik Alex , Casey Kenneth L. , Davidson Richard J. , Kosslyn Stephen M. , Rose Robert M. , Cohen Jonathan D.
Published: February 2004

The experience of pain arises from both physiological and psychological factors, including one's beliefs and expectations. Thus, placebo treatments that have no intrinsic pharmacological effects may produce analgesia by altering expectations. However, controversy exists regarding whether placebos alter sensory pain transmission, pain affect, or simply produce compliance with the suggestions of investigators. In two functional magnetic resonance imaging (fMRI) experiments, we found that placebo analgesia was related to decreased brain activity in pain-sensitive brain regions, including the thalamus, insula, and anterior cingulate cortex, and was associated with increased activity during anticipation of pain in the prefrontal cortex, providing evidence that placebos alter the experience of pain.
Niemann-Pick C1 Like 1 Protein Is Critical for Intestinal Cholesterol Absorption
Authors: Altmann Scott W. , Davis Harry R. , Zhu Li-ji , Yao Xiaorui , Hoos Lizbeth M. , Tetzloff Glen , Iyer Sai Prasad N. , Maguire Maureen , Golovko Andrei , Zeng Ming , Wang Luquan , Murgolo Nicholas , Graziano Michael P.
Published: February 2004

Dietary cholesterol consumption and intestinal cholesterol absorption contribute to plasma cholesterol levels, a risk factor for coronary heart disease. The molecular mechanism of sterol uptake from the lumen of the small intestine is poorly defined. We show that Niemann-Pick C1Like 1(NPC1L1) protein plays a critical role in the absorption of intestinal cholesterol. NPC1L1 expression is enriched in the small intestine and is in the brush border membrane of enterocytes. Although otherwise phenotypically normal, NPC1L1-deficient mice exhibit a substantial reduction in absorbed cholesterol, which is unaffected by dietary supplementation of bile acids. Ezetimibe, a drug that inhibits cholesterol absorption, had no effect in NPC1L1 knockout mice, suggesting that NPC1L1 resides in an ezetimibe-sensitive pathway responsible for intestinal cholesterol absorption.
Repeating Seismic Events in China
Authors: Schaff David P. , Richards Paul G.
Published: February 2004

About 10% of seismic events in and near China from 1985 to 2000 were repeating events not more than about 1 kilometer from each other. We cross-correlated seismograms from ∼14,000 earthquakes and explosions and measured relative arrival times to ∼0.01 second, enabling lateral location precision of about 100 to 300 meters. Such precision is important for seismic hazard studies, earthquake physics, and nuclear test ban verification. Recognition and measurement of repeating signals in archived data and the resulting improvement in location specificity quantifies the inaccuracy of current procedures for picking onset times and locating events.
Empathy for Pain Involves the Affective but not Sensory Components of Pain
Authors: Singer Tania , Seymour Ben , O'Doherty John , Kaube Holger , Dolan Raymond J. , Frith Chris D.
Published: February 2004

Our ability to have an experience of another's pain is characteristic of empathy. Using functional imaging, we assessed brain activity while volunteers experienced a painful stimulus and compared it to that elicited when they observed a signal indicating that their loved one—present in the same room—was receiving a similar pain stimulus. Bilateral anterior insula (AI), rostral anterior cingulate cortex (ACC), brainstem, and cerebellum were activated when subjects received pain and also by a signal that a loved one experienced pain. AIand ACC activation correlated with individual empathy scores. Activity in the posterior insula/secondary somatosensory cortex, the sensorimotor cortex (SI/MI), and the caudal ACC was specific to receiving pain. Thus, a neural response in AIand rostral ACC, activated in common for “self” and “other” conditions, suggests that the neural substrate for empathic experience does not involve the entire “pain matrix.” We conclude that only that part of the pain network associated with its affective qualities, but not its sensory qualities, mediates empathy.
Direct Measurement of Energy Thresholds to Conformational Isomerization in Tryptamine
Authors: Dian Brian C. , Clarkson Jasper R. , Zwier Timothy S.
Published: February 2004

Stimulated emission pumping (SEP)–hole filling spectroscopy and SEP-induced population transfer spectroscopy have been used to place narrow bounds on the energy thresholds for isomerization between individual reactant-product isomer pairs involving the seven conformational minima of tryptamine. The thresholds for isomerizing conformer A to all six other conformations divided into three groups at 750 wavenumbers (cm
–1
)(A→B, F), 1000 cm
–1
[A→C(2)], and 1280 to 1320 cm
–1
[A→D, E, and C(1)]. The appearance of the first band and the absence of the band below it were used to place upper and lower bounds to the barrier heights for each process. The thresholds for A→B and B→A isomerizations were also combined to determine the relative energies of these two lowest energy minima. The combined data from all X→Y isomerizations identify important isomerization pathways on the potential energy surface linking the minima.
Fragmentation in Massive Star Formation
Authors: Beuther Henrik , Schilke Peter
Published: February 2004

Studies of evolved massive stars indicate that they form in a clustered mode. During the earliest evolutionary stages, these regions are embedded within their natal cores. Here we present high-spatial-resolution interferometric dust continuum observations disentangling the cluster-like structure of a young massive star–forming region. The derived protocluster mass distribution is consistent with the stellar initial mass function. Thus, fragmentation of the initial massive cores may determine the initial mass function and the masses of the final stars. This implies that stars of all masses can form via accretion processes, and coalescence of intermediate-mass protostars appears not to be necessary.
The Structure of a Mycobacterial Outer-Membrane Channel
Authors: Faller Michael , Niederweis Michael , Schulz Georg E.
Published: February 2004

Mycobacteria have low-permeability outer membranes that render them resistant to most antibiotics. Hydrophilic nutrients can enter by way of transmembrane-channel proteins called porins. An x-ray analysis of the main porin from
Mycobacterium smegmatis
, MspA, revealed a homooctameric goblet-like conformation with a single central channel. This is the first structure of a mycobacterial outer-membrane protein. No structure-related protein was found in the Protein Data Bank. MspA contains two consecutive β barrels with nonpolar outer surfaces that form a ribbon around the porin, which is too narrow to fit the thickness of the mycobacterial outer membrane in contemporary models.
Biography of a Brilliant Birdwatcher
Authors: Bolhuis Johan J.
Published: February 2004

Niko's Nature
A Life of Niko Tinbergen and His Science of Animal Behaviour. by Hans Kruuk. Oxford University Press, Oxford, 2003. $30, £20. ISBN 0-19-851558-8.

Kruuk examines the life and science of the renowned ethologist who helped found the discipline of behavioral biology.
Danger in Wonderland
Authors: Albert Matthew L.
Published: February 2004

The Matrix Revolutions
. Written and Directed by Andy Wachowski and Larry Wachowski. Warner Brothers, 1999, 2003, and 2003.

Our reviewer considers similarities and differences between the world of
The Matrix
and the organization of the immune system.
AN EXPLICIT SUBPARAMETRIC SPECTRAL ELEMENT METHOD OF LINES APPLIED TO A TUMOUR ANGIOGENESIS SYSTEM OF PARTIAL DIFFERENTIAL EQUATIONS
Authors: VALENCIANO J. , CHAPLAIN M. A. J.
Published: February 2004

In this paper we consider a numerical solution to Anderson and Chaplain's tumour angiogenesis model1 over two-dimensional complex geometry. The numerical solution of the governing system of non-linear evolutionary partial differential equations is obtained using the method of lines: after a spatial semi-discretisation based on the subparametric Legendre spectral element method is performed, the original system of partial differential equations is replaced by an augmented system of stiff ordinary differential equations in autonomous form, which is then advanced forward in time using an explicit time integrator based on the fourth-order Chebyshev polynomial. Numerical simulations show the convergence of the steady state numerical solution towards the linearly stable steady state analytical solution.
LIMIT BEHAVIOUR OF A DENSE COLLECTION OF VORTEX FILAMENTS
Authors: BESSAIH H. , FLANDOLI F.
Published: February 2004

The understanding of vortex structures in 3D turbulent fluids is a basic problem. One of the questions is whether some large scale structure can emerge as the macroscopic result of the self-organization of small scale vortex filaments, similarly to the 2D case of point vortices. This paper gives a first step in this direction: a mean field result is proved for a dense collection of vortex filaments. The filaments considered here are described by stochastic processes, including Brownian motion. Under a special rescaling of the energy, a mean field result is proved for a model of 3D vortex filaments described by stochastic processes, including Brownian motion, Brownian bridge, fractional Brownian motion and other semimartingales. Propagation of chaos, variational characterization of the limit Gibbs density h and an equation for h are proved.
STUDY OF A MATHEMATICAL MODEL FOR STIMULATED RAMAN SCATTERING
Authors: BOUCHERES T. , COLIN T. , NKONGA B. , TEXIER B. , BOURGEADE A.
Published: February 2004

We study a semiclassical modelization of the interaction of a laser with a mono-atomic gas. The Maxwell equations are coupled with a three-level version of the Bloch equations. Taking into account the specificities of the laser pulse and of the gas, we introduce small parameters and a dimensionless form of the equations. To describe stimulated Raman scattering, we perform a three-scale WKB expansion in the weakly nonlinear regime of geometric optics. The limit system is of Schrödinger–Bloch type. We prove a global existence result for this system and the convergence of its solution toward the solution of the initial Maxwell–Bloch equations, as the parameter of the WKB expansion goes to 0. We put in evidence Raman instability in the one-dimensional case, both theoretically and numerically.
LINEAR PARABOLIC EQUATIONS IN LOCALLY UNIFORM SPACES
Authors: ARRIETA JOSE M. , RODRIGUEZ-BERNAL ANIBAL , CHOLEWA JAN W. , DLOTKO TOMASZ
Published: February 2004

We analyze the linear theory of parabolic equations in uniform spaces. We obtain sharp Lp-Lq-type estimates in uniform spaces for heat and Schrödinger semigroups and analyze the regularizing effect and the exponential type of these semigroups. We also deal with general second-order elliptic operators and study the generation of analytic semigoups in uniform spaces.
NUMERICAL SOLUTION OF TWO-FACTOR MODELS FOR VALUATION OF FINANCIAL DERIVATIVES
Authors: BERMÚDEZ ANA , NOGUEIRAS MARÍA R.
Published: February 2004

In this paper we propose a general methodology to solve partial differential inequalities arising in the valuation of financial derivatives. Firstly we show how to build up a weak formulation and how to discretize it by implicit finite difference schemes in time and finite elements in space and we propose an iterative algorithm to solve the discrete variational inequality. Although the methodology is quite general, here it is applied to solve two important two-factor models: one for valuation of dividend paying Amerasian options and another for convertible bonds with stochastic interest rate and call and put features. In both cases we validate our results with some others existing in the literature.
On a boundary value problem for scalar linear functional differential equations
Authors: Hakl R. , Lomtatidze A. , Stavroulakis I. P.
Published: February 2004

Theorems on the Fredholm alternative and well‐posedness of the linear boundary value problem u′(t) = ℓ(u)(t) + q(t), h(u) = c, where ℓ : C([a, b]; ℝ) → L([a, b]; ℝ) and h : C([a, b]; ℝ) → ℝ are linear bounded operators, q ∈ L([a, b]; ℝ), and c ∈ ℝ, are established even in the case when ℓ is not a strongly bounded operator. The question on the dimension of the solution space of the homogeneous equation u′(t) = ℓ(u)(t) is discussed as well.
Laplace transform generation theorems and local Cauchy problems
Authors: Müller Claus
Published: February 2004

We give new criterions to decide if some vector‐valued function is a local Laplace transform and apply this to the theory of local Cauchy problems. This leads to an improvement of known results and new Hille‐Yosida‐type theorems for local convoluted semigroups.
At the Crossroads of Myocardial Signaling
Authors: Pyle W. Glen , Solaro R. John
Published: February 2004

Understanding the molecular interactions among components of cardiac Z-discs and their role in signaling has become pivotal in explaining long- and short-term regulation of cardiac function. In striated muscle, the ends of the thin filaments from opposing sarcomeres overlap and are cross-linked by an elaborate array of proteins to form a highly ordered, yet dynamic network that is the Z-disc. We review here a current picture of the function and structure of the Z-disc of mammalian cardiac myocytes. We emphasize provocative findings that advance new theories about the place of cardiac Z-discs in myocardial intra- and intercellular signaling in myocardial physiology and pathology. Relatively new approaches, especially yeast two-hybrid screens, immunoprecipitation, and pull down assays, as well as immunohistochemical analysis have significantly altered previous views of the protein content of the Z-disc. These studies have generally defined domain structure and binding partners for Z-disc proteins, but the functional significance of the binding network and of the domains in cardiac cell biology remains an unfolding story. Yet, even at the present level of understanding, perceptions of potential functions of the Z-disc proteins are expanding greatly and leading to new and exciting experimental approaches toward mechanistic understanding. The theme of the following discussion of these Z-disc proteins centers on their potential to function not only as a physical anchor for myofilament and cytoskeletal proteins, but also as a pivot for reception, transduction, and transmission of mechanical and biochemical signals.
Development Gone Awry
Authors: Gruber Peter J. , Epstein Jonathan A.
Published: February 2004

Significant advances in the understanding of the molecular and genetic basis of congenital heart disease have emerged from gene inactivation studies in mice and from human genetic investigations. However, the ability to utilize information gleaned from animal models to inform clinical care of patients depends on an accurate anatomic analysis and presentation in terms that are meaningful to the clinical pediatric cardiologist. Likewise, the enormous depth and breadth of accumulated clinical experience can inform the developmental biologist and can highlight the importance and interrelationships of particular phenotypes. The explosion of potentially informative genetic tools demands that basic scientists and clinicians concerned with congenital cardiac disease enhance the ongoing bidirectional dialogue. In some cases, categories of congenital disease familiar to clinicians are not recognized by developmental biologists, and mechanisms accepted by the biologist seem inconsistent with clinical experience. In this review, we summarize some of the more clinically significant forms of congenital heart disease, and we highlight relevant genetic and developmental pathways.
The Giant Protein Titin
Authors: Granzier Henk L. , Labeit Siegfried
Published: February 2004

The sarcomere contains, in addition to thin and thick filaments, a filament composed of the giant protein titin (also known as connectin). Titin molecules anchor in the Z-disc and extend to the M-line region of the sarcomere. The majority of titin’s I-band region functions as a molecular spring. This spring maintains the precise structural arrangement of thick and thin filaments, and gives rise to passive muscle stiffness; an important determinant of diastolic filling. Earlier work on titin has been reviewed before. In this study, our main focus is on recent findings vis-à-vis titin’s molecular spring segments in cardiac titins, including the discovery of fetal cardiac isoforms with novel spring elements. We also discuss new insights regarding the role of titin as a biomechanical sensor and signaling molecule. We will end with focusing on the rapidly growing knowledge regarding titinopathies.
The effects of track non-linearity on wheel/rail impact
Authors: Wu T. X. , Thompson D. J.
Published: February 2004

Wheel/track impact due to rail joints or wheel flats has been studied over many years. The railway track is usually assumed to be linear in order to simplify the track model, although the rail pad and ballast are actually non-linear. This may cause incorrect results to some extent in some circumstances, as the pad and ballast stiffness varies with load. In this paper wheel/track impact is studied using a non-linear track model. The rail is represented by a finite element (FE) model and is supported by a non-linear track foundation. Wheel/track impacts are simulated at different train speeds and three types of rail pad, soft, medium and stiff, are used in the simulations. It is shown that the impact forces rise dramatically when the stiff rail pads are used. On the other hand, using soft pads can reduce impact forces significantly. Compared with the results from the linear track model, both the impact force and the track vibration level are shown to be noticeably higher from the nonlinear track than those from the linear track. It is therefore concluded that linear track models are not appropriate for wheel/track impact because the track foundation stiffness varies dramatically under the impact force.
Two-/three-dimensional hybrid model of the thermomechanical behaviour of disc brakes
Authors: Dufrénoy P
Published: February 2004

Prediction of the surface temperature in friction braking systems is the main problem in the analysis of thermal dissipation and surface degradations such as wear, phase transformation, cracks, etc. The first difficulty of the thermal prediction is presented by the complex interactions between the thermal, mechanical and tribological behaviour. The second problem is due to the multiscale aspect, from the macroscopic response of the disc and brake pads (conduction, distortions, etc.) to local surface effects (surface roughness, wear debris, phase changes, etc.). This paper aims to propose a macrostructural model of the thermomechanical behaviour of the disc brake, taking into account the real three-dimensional geometry of the disc-pad couple. Contact surface variations, distortions and wear are taken into account. Real body geometry and thermoelastoplastic modelling of the disc material are specially introduced. Such a model aims to give predictions of the thermal gradients varying with time and of the thermomechanical response of the components. Predictions of the temperature distributions are compared with experimental measurements obtained by thermographs and thermocouples. Such a model seems to be a suitable base for the study of the thermal dissipation and the thermomechanical behaviour and for the introduction of local friction effects.
High speed and track deterioration: The role of vertical stiffness of the track
Authors: Pita A Lopez , Teixeira P. F. , Robuste F
Published: February 2004

The aims of this article are as follows. Firstly, the importance of vertical track stiffness on high-speed lines is emphasized. Secondly, it proposes an optimum range for this vertical stiffness value, establishing parallel equations that enable the influence of every elastic component located under the rail to be quantified (base plates, ballast and subgrade) in total track stiffness. Finally, a range of variations is proposed for base-plate vertical stiffness.
A neural network approach to estimate the top speed and trainset configuration of a high-speed train
Authors: Lee J , Han S
Published: February 2004

The prediction of top speeds of a high-speed train and the configuration design of train formations has been studied using a neural network with backpropagation. High-speed trains, such as KHST-K, KHST-11 and KHST-20 which will be operated in Korea, are used for the teaching data of the neural network. Other high-speed trains of other countries, such as ICE, Shinkansen and TGV, are also used for the data of neural networks. The input data for top speed prediction consist of values that are closely related to traction force, propulsion resistance and train formation. KHST-20 test trains are composed of power cars and passenger cars and have modified train formations. The top speeds have been predicted using neural networks. The configuration design of a train formation has also been performed using neural networks with backpropagation, which determine the basic train formation, such as weight, power, the number of cars, the number of motor cars and the number of traction motors in a high-speed train. The train formation of the KHST-20 test train is configured by the neural network and compared with the actual train formation. The design of Shinkansen 700 and KHST-20 is also configured using neural networks. In the configuration design of KHST-20, two types of train were used for the teaching data of the neural network. These were the power concentrated train and the power distributed train. Neural networks of each set of data estimate very different train formations from the same input value.
Prediction of the press-fit curve in the assembly of a railway axle and wheel
Authors: Benuzzi D , Donzella G
Published: February 2004

A methodology for the prediction of the press-fit curve in the assembly of a railway axle and wheel is described. It starts from friction measurements on samples taken directly from the two components. A new apparatus, adaptable to a common axial testing machine, was developed for this aim: it permits the contact pressure and sliding speed to be varied in order to change the lubrication condition of the contact surfaces.

Two calculation models are then proposed to predict the press-fit curves. They take the results of the friction measurements as input data, together with the wheelset geometry, the design interference and the material characteristics. The first one is a finite element method (FEM) model, which is very accurate but difficult to use, which also allows the effect of the wheel seat chamfer and the oil injection grove to be assessed. The second one is a simplified analytical model based on the theory of axisymmetric bodies, which works on an approximate wheel geometry; nevertheless, it gives results in good agreement with those of the FEM model and with the experimental press-fit curves of the examined wheelsets. Moreover, the simplified model is very fast and easy to use, thus constituting a powerful and useful tool for the design of new wheelsets.
Investigating the capacity of a Metro line by means of a simulation model
Authors: Ballis A , Liberis K , Moschovou T
Published: February 2004

The expansion of the urban railway in the city of Athens with two new Metro lines required the upgrading of the existing infrastructure in order to comply with the new modern lines in terms of capacity and quality of service. This paper presents a simulation-based modelling tool that was developed and used for the purposes of the relevant capacity analysis. The model offers a graphical and interactive environment that facilitates the calculations, provides the necessary information and allows for sensitivity analysis under user-defined scenarios that enable the investigation of the behaviour of the system when longer than anticipated delays or abnormal situations occur. It also allows for the investigation of the synchronization of the trains that enter the system after the turn back procedures in the intermediate stations.
The making of local child daycare regimes: past and future
Authors: Randall Vicky
Published: February 2004

English

The government's new child daycare policy, based on local ‘partnerships’, must reckon with tremendous local diversity of provision. This article draws on case studies of six English local authorities – Barnet, Kensington and Chelsea, Leeds, Manchester, Oxfordshire and North Tyneside – first to characterise more fully this variation of local daycare regimes and second, to explore the role played in shaping and modifying these regimes by local party and gender politics. The conclusion considers implications for local responses to recent national childcare initiatives.
Managerialism meets community development: contracting for social inclusion?
Authors: Turner David , Martin Steve
Published: February 2004

English

The government-funded Neighbourhood Support Fund (NSF) programme, launched in March 2000, sought to tackle exclusion among disaffected young people in the most disadvantaged areas of England. NSF reflected a decisive policy shift – rejecting state-centric youth service provision in favour of direct funding of community-led initiatives. This article highlights important tensions between the government's aim of promoting innovative, community-based solutions and its emphasis on the rapid ‘delivery’ of tangible improvements. It raises questions about the capacity of local authorities and community-based groups to champion such initiatives. Early evidence suggests that implementing such a ‘joined-up’ approach requires a framework which is more conducive to collaboration between the statutory, voluntary and community sectors than that which currently exists.
Mainstreaming equality in Wales: the case of the National Assembly building
Authors: Edwards Julia
Published: February 2004

English

Institutional discrimination in public policy denies equality of opportunity to the diversity of citizens. Mainstreaming, or building in, equality at initiation stage of policy making may be the best way of overcoming this problem. A case study of the initial stages of choosing a design for the National Assembly of Wales’ debating chamber reveals that mainstreaming equality requires a more inclusive practice of policy making than is usually achieved by the traditional Whitehall model.
Mainstreaming: Northern Ireland's participative-democratic approach
Authors: Donaghy Tahnya Barnett
Published: February 2004

English

At a time when both practitioners and academics are calling for a greater understanding and more research into gender mainstreaming, this article develops both a practical case study and explores some of the deeper conceptual understandings of mainstreaming models. Specifically, the article places Northern Ireland within the emerging literature on mainstreaming, establishing it as a valuable case study, based on the breadth and depth of the approach adopted since devolution. The article then develops the understanding of the participative-democratic mainstreaming model from a description of processes to include an understanding of the impact of the origins of mainstreaming on model design.
The post-devolution equality agenda: the case of the Welsh Assembly's statutory duty to promote equality of opportunity
Authors: Chaney Paul
Published: February 2004

English

Within the context of the devolution statutes introduced by the 1997 UK Parliament, the Welsh Assembly's statutory equality imperative is unique in its non-prescriptive phrasing and all-embracing scope; it requires government to promote equality of opportunity for all people in the exercise of all its functions. Written at the end of the National Assembly for Wales's first term, this article sets out the background to the duty, explores its impact and tests two propositions by equality experts, namely: that constitutional reform has provided an “enabling context within which equalities work can develop” and that “different priorities and agenda can be discerned”.
Governance and sustainability: an investigation of the role of policy mediators in the European Union policy process
Authors: Williams Andrew
Published: February 2004

English

This article argues that changing governance modes in the European Union (EU), including territorial multi-level governance and the dispersion of decision-making authority in policy networks, along with the separation of functions at all governance levels, is often characterised by fragmentation in the policy process. This causes difficulties for policy makers in identifying and avoiding unintended ex post policy outcomes, including ‘trade-offs’ between economic, social and environmental objectives that, in the context of sustainability, are sub-optimal. A case study of the implementation of the EU Ozone Depleting Substances Regulation in the UK tests this hypothesis. It is then suggested that policy mediators have an important role to play in facilitating the effective coordination of policy formulation and implementation in a manner commensurate with broad sustainable development objectives.
On racemic and L-malates: a comparison of their crystal structures
Authors: Fleck Michel , Tillmanns Ekkehart , Bohatý Ladislav , Held Peter
Published: February 2004

The crystal structures of eight different L-malates have been determined and refined from single-crystal X-ray diffraction data. The compounds are the monoclinic (space group P21, Z = 2) L-malates Ca(C4H4O5)·3H2O (a = 6.652(1) Å, b = 8.378(1) Å, c = 8.268(1) Å, β = 112.65(2)°, R = 0.027), Ni(C4H4O5)·3H2O (a = 5.762(1) Å, b = 9.006(2) Å, c = 8.406(1) Å, β = 105.54(1)°, R = 0.024), CuH2
(C4H4O5)2 (a = 9.911(1) Å, b = 5.271(1) Å, c = 11.510(1) Å, β = 109.33(1)°, R = 0.031), CsH(C4H4O5)·H2O (a = 7.439(1) Å, b = 7.481(1) Å, c = 7.852(1) Å, β = 116.67(1)°, R = 0.027) as well as the four isomorphic tetragonal (space group P41212, Z = 4) L-malates MgH2
(C4H4O5)2·4H2O (a = 7.524(1) Å, c = 27.459(2) Å, R = 0.041), MnH2
(C4H4O5)2·4H2O (a = 7.548(1) Å, c = 27.707(2) Å, R = 0.027), CoH2
(C4H4O5)2·4H2O (a = 7.519(1) Å, c = 27.537(2) Å, R = 0.030) and ZnH2
(C4H4O5)2·4H2O (a = 7.533(1) Å, c = 27.360(2) Å, R = 0.029). A comparison of the atomic arrangements of L-malates with their racemic counterparts shows different aspects of symmetry as well as differences in the connectivity of the building units.

In addition, for all the compounds, powder diffraction data were collected, analysed and submitted to the powder diffraction file (PDF).
Crystal and electronic structure of aqua(N-salicylidene-methylester-l-glutamato)Cu(II) monohydrate
Authors: Langer Vratislav , Gyepesová Dalma , Scholtzová Eva , Mach Pavel , Kohútová Mária , Valent Aladár , Smrčok L'ubomír
Published: February 2004

The absolute structure of the title compound, CuNC13H17O7, has been determined. The crystal structure consists of the molecular units Cu(N-sal-5-met-L-glu)(H2O) connected by a three-dimensional network of hydrogen bonds. The coordination polyhedron in the complex is approximately square-pyramidal with a pentacoordinated Cu(II) atom. The base of the pyramid is formed by nitrogen and oxygen atoms belonging to the molecule, while the apex of the pyramid contains a weakly bonded oxygen atom of the carboxylic group of another molecule. The B3LYP/SVP method and basis set in Gaussian98 was used for quantum chemical calculation of the nature of Cu–X (X = O, N) bonds. While the calculated dissociation energy of the weakly bonded crystalline water is only 17.2 kJ/mol, the bonding energy of the water molecule coordinating to the Cu atom is 62.3 kJ/mol.
Twin point groups and the polychromatic symmetry of twins
Authors: Nespolo Massimo
Published: February 2004

A new classification in terms of the number of independent twin elements is introduced and exploited to analyze the symmetry of multiple twins. The dichromatic point group description of twins is revised showing that, contrary to what stated in the previous literature, all the 58 dichromatic point groups represent the possible symmetry of some twins. This approach is extended in terms of polychromatic point groups and applied to some examples from the recent literature.
Bravais colourings of planar modules with N-fold symmetry
Authors: Baake Michael , Grimm Uwe
Published: February 2004

The first step in investigating colour symmetries for periodic and aperiodic systems is the determination of all colouring schemes that are compatible with the symmetry group of the underlying structure, or with a subgroup of it. For an important class of colourings of planar structures, this mainly combinatorial question can be addressed with methods of algebraic number theory. We present the corresponding results for all planar modules with N-fold symmetry that emerge as the rings of integers in cyclotomic fields with class number one. The counting functions are multiplicative and can be encapsulated in Dirichlet series generating functions, which turn out to be the Dedekind zeta functions of the corresponding cyclotomic fields.
Intensity distribution of the eight-beam case of the Si-888 reflection in backscattering geometry
Authors: Haubold Stefan , Liss Klaus D. , Hock Rainer , Magerl Andreas , Lorenzen Maren , Krisch Michael
Published: February 2004

The eight-beam case of the Si-888 reflection in backscattering has been studied by scanning the eight simultaneously excited reflections Si 888, Si 088, Si 880, Si 808, Si 800, Si 080, Si 008 and Si 000 in wavelength and two independent rocking angles. Largely different widths of the individual reflection profiles found are explained from the Ewald representation as suggested by kinematic diffraction theory. The intensity profiles demonstrate a coupling of the eight simultaneously excited wave fields as expected from dynamic diffraction theory.
Crystal structures of GaX
3 (X = Cl, Br, I) and AlI3
Authors: Troyanov Sergey I. , Krahl Thoralf , Kemnitz Erhard
Published: February 2004

Crystal structures of GaX
3 (X = Cl (I), Br (II), and I (III)) and AlI3 (IV) were determined at low temperature by single crystal X-ray crystallography. I is monoclinic, space group C2/m with a = 11.948(4), b = 6.855(3), c = 7.050(3) Å, β = 125.69(3)°, Z = 4, R
1 = 0.038. II–IV are isotypic to each other: II is monoclinic, space group P21/c with a = 8.874(4), b = 5.637(2), c = 11.006(4) Å, β = 107.81(4)°, Z = 4, R
1 = 0.056; III: a = 9.584(3), b = 6.084(2), c = 11.839(4) Å, β = 107.78(3)°, R
1 = 0.044; IV: a = 9.591(3), b = 6.069(2), c = 11.902(3) Å, β = 108.05(3)°, R
1 = 0.046. The crystal structures I–IV are built of dimeric M
2
X
6 molecules consisting of two MX
4 tetrahedra sharing a common XX edge with shorter M-X (terminal) and longer M-X(bridging) distances. The structure of I can not be described in terms of the closest Cl packing, whereas the structures of II–IV are based on slightly distorted cubic closest packing of halogen atoms, which accounts for their strong tendency to twinning.
Two new ammonium diphosphates: crystal structure of Mn0.5NH4H2P2O7·H2O and MnNaNH4P2O7·3H2O
Authors: Capitelli Francesco , Brouzi Khalid , Harcharras Mohamed , Ennaciri Abdelaziz , Moliterni Anna G. G. , Bertolasi Valerio
Published: February 2004

Two new ammonium diphosphates, Mn0.5NH4H2P2O7·H2O (1) and MnNaNH4P2O7·3H2O (2), have been synthesized and investigated by single crystal X-ray diffraction. Compound (1) crystallizes in the triclinic space group P1̅, and the unit cell dimensions are a = 7.0029(2) Å, b = 7.4401(2) Å, c = 7.8771(2) Å, α = 80.444(1)°, β = 71.359(1)°, γ = 87.408(1)°, V = 383.48(2) Å3, Z = 2; compound (2) crystallizes in the monoclinic space group Cc, with the following unit cell dimensions: a = 10.1124(4) Å, b = 16.4448(7) Å, c = 5.6000(3) Å, β = 104.304(2)°, V = 902.39(7) Å3, Z = 4. Final residuals are: R = 0.0281 and w
R = 0.0769, by using 2356 reflections with I > 2σ(I), for (1); R = 0.0301 and w
R = 0.0682, by using 2322 reflections with I > 2σ(I), for (2). The crystal packing of Mn0.5NH4H2P2O7·H2O consists of layers parallel to ac plane formed by MnO6 regular octahedra, H2P2O7 double tetrahedra and ammonium cations. Strong hydrogen bonds embed the dihydrogendiphosphate groups in the framework. The crystal packing of MnNaNH4P2O7·3H2O is made up of layers of P2O7 double tetrahedra, NaO7 monocapped octahedra and MnO6 regular octahedra down c. Water and ammonium cations molecules fill up the cavities between the above mentioned polyhedra. Strong hydrogen bonds complete the network.
´Pseudopolymorphs′ of 3aβ,4α-dihydro-4β,10-dimethyl-2-phenyl-1H,3H,5H-pyrrolo[3,4-b]carbazol-1,3-dione
Authors: Dziubek Kamil F. , Katrusiak Andrzej
Published: February 2004

A crystal structure of 3aβ,4α-dihydro-4β,10-dimethyl-2-phenyl-1H,3H,5H-pyrrolo[3,4-b]carbazol-1,3-dione, mistakenly presented as two polymorphs [Acta Crystallogr. B51 (1995) 999–1003] illustrates a general problem of validating crystallographic data described in different unit-cell settings.
Performance analysis of CDMA unslotted ALOHA system employing successive interference cancellation
Authors: Tadokoro Yukihiro , Okada Hiraku , Yamazato Takaya , Katayama Masaaki , Ogawa Akira
Published: February 2004

Multiple access interference (MAI) occurs in the CDMA Unslotted ALOHA system and is a significant factor for degradation of performances. Further, in this system, there are frequent situations in which the received signal power becomes inhomogeneous so that the effect of the MAI is enhanced. Presently, an interference cancellation technique is developed as a way to suppress the MAI. However, this method mainly deals with a system that transmits and receives signals continuously in time. The evaluation of the performances is also by means of the bit error rate. In the packet communication system, success or failure of the transmission of each packet rather than of the transmission of each bit is the key to system performances. Hence, in the present study, a system is proposed that uses a successive interference cancellation as one of the interference cancellation techniques to the CDMA Unslotted ALOHA system. The throughput performance is analytically derived for performance evaluation. Also, in general, the performances under the situation of unequal received signal power are worse than those for equal received power. However, in the proposed system, performance can be better in an unequal received power environment than in the equal power case. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(6): 32–43, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10116
Estimation of discrete‐time software rejuvenation schedule based on the cost‐effectiveness
Authors: Dohi Tadashi , Iwamoto Kazuki , Okamura Hiroyuki , Kaio Naoto
Published: February 2004

In this paper, the probability model for determination of the rejuvenation schedule of the software system treated by Huang and colleagues (1995) and by Dohi and colleagues (2001) is discussed. In particular, under the evaluation criterion of cost‐effectiveness, two discrete time models are analyzed and an optimum software rejuvenation schedule maximizing cost‐effectiveness is derived. Further, a statistical procedure for estimation of an optimal software rejuvenation schedule is discussed in which no probability distribution is specified from the failure time data. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(6): 23–31, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10128
Aperiodic autocorrelation functions of real‐valued shift‐orthogonal finite‐length sequences with round‐off errors
Authors: Matsumoto Takahiro , Tanada Yoshihiro
Published: February 2004

A real‐valued shift‐orthogonal finite‐length sequence is a sequence for which the side‐lobe of the aperiodic autocorrelation function is zero except at the two ends. It is effectively used in spread‐spectrum communications and other applications. This type of sequence can be synthesized by using element sequences of adequate lengths. Consequently, fast correlation processing can be realized by dividing the process for each element sequence. A problem in this sequence is that the round‐off error of its real values has an effect on the correlation characteristics. Therefore, this paper investigates the effect of the round‐off error on integrated correlation processing and divided correlation processing. In the former, the mean‐square error of the correlation output is inversely proportional to the sequence length. In the latter, it is the sum of the mean‐square errors of the element sequences, which are inversely proportional to the respective sequence lengths. Thus, we see that the error of shorter element sequences should be reduced in the latter method in order to speed up correlation processing. This paper considers in particular a method by which the mean‐square error is reduced without significantly enlarging the circuit scale. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(6): 1–12, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10152
Watermark detection based on error probability and its applications to video watermarking
Authors: Choi Yoonki , Aizawa Kiyoharu
Published: February 2004

As digital media which can be copied and edited readily without loss of quality has spread, several electronic watermarking methods used to protect copyrights and prevent illegal copying have been proposed. Electronic watermarking technology which can embed author information secretly in data consists primarily of embedding the watermark information, extracting watermark information, and verifying watermark information. Various methods have been proposed for embedding and extracting watermark information, depending on the scope of use and purpose. On the other hand, methods to verify the detected watermark information are limited, with BER (Bit Error Rate) and correlation between the extracted watermark information and the original watermark information widely used for evaluation. In contrast, in this paper, the authors propose a method to verify electronic watermarks based on probability. In the proposed method, the reliability that the original watermark information is embedded in the detected image is calculated as a probability, and then using this value, whether or not the watermark information is there is determined. The calculated value gives an evaluation value directly, one that includes the number of bits in the original watermark information. As a result, this verification method can be considered valid for use with video, in which watermarks are repeated. The authors use experiments to confirm the validity of their method by applying it to electronic watermarks for still images and video. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(6): 66–76, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20083
User interface design based on phase‐oriented information classification
Authors: Mitsuda Naruki , Ajisaka Tsuneo , Sawada Atsushi
Published: February 2004

New modeling techniques are needed for providing development environments for software having high general applicability. Information handled by software differs in form depending on its procedures and requires different handling methods. Such methods include methods of recognizing these as phases of information and dividing them into modules that correspond to the information phases. This study proposes a software development environment based on the recognition of information phases in a user interface. It implements a specific user interface by recognizing three phases of information—panel information, operation information, presentation information—and defining the methods of handling information for each phase. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(6): 44–54, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20085