bluuebunny/crossref_metadata_2025 huggingface dataset:
SUSTAINABILITY ASSESSMENT: THE APPLICATION OF A METHODOLOGICAL FRAMEWORK
Authors: DEVUYST DIMITRI
Published: May 2003

Research shows that the basic principles of Environmental Impact Assessment (EIA) are being applied to other than purely environmental issues. The demand for EIA at higher levels of planning and policy making, strategic environmental assessment (SEA), has given rise to a discussion about the need for an appropriate assessment or reference framework. This discussion is linked to the question of how sustainable development principles can be introduced in the decision making process. A general methodological framework for sustainability assessment, the so-called ASSIPAC-method (Assessing the Sustainability of Societal Initiatives and Proposing Agendas for Change) is presented. Two cases dealing with company transportation management plans illustrate the application of the ASSIPAC-method. Opportunities and limitations of the proposed sustainability assessment methodology are discussed.
DEVELOPING MUNICIPAL CAPACITY FOR EIA IN SLOVAKIA
Authors: WILSON ELIZABETH , ŠVIHLOVÁ DANA
Published: May 2003

Effective implementation of environmental policy proves difficult in many countries. Even where there is a comprehensive policy framework, the capacity for implementation at the local level may be weak. In some countries of central and eastern Europe, such as Slovakia, local government has acquired new environmental responsibilities, but lacks the capacity for exercising these roles. The Slovakian environmental impact assessment (EIA) law, for example, gives local government a role as a channel for public comment. However, most municipalities lack the technical expertise or political experience to play an effective role in the EIA process.

This paper describes a project supported by the UK Know-How Fund with Slovakian partners to develop municipal capacity. It offers a preliminary evaluation of the effectiveness of the programme, and emphasises the need for training in EIA to relate to municipalities' other environmental responsibilities. It draws some conclusions on cross-national learning between local government in central and western Europe.
A METHODOLOGICAL FRAMEWORK FOR THE INITIAL ENVIRONMENTAL REVIEW (IER) IN EMS IMPLEMENTATION
Authors: CAGNO ENRICO , DI GIULIO AUGUSTO , TRUCCO PAOLO
Published: May 2003

Organisations are increasingly interested in understanding the impact of the environmental issues associated with their sites on company competitiveness and strategies. Within the implementation of an environmental management system (EMS), the initial environmental review (IER) is a first step in which a company begins to consider systematically all the factors driving the complex relationships between its production system and the external environment. Therefore, IER plays a crucial role in the definition of effective environmental policy and programmes and demands significant company resources. The paper focuses on the identification of the main objectives of the IER and the features characterising a methodological approach. These are then used to develop a methodological framework for IER that allows to integrate business strategy in establishing significant environmental aspects of a specific site. Indeed, companies are increasingly involved in managing the environment as an opportunity for competitive advantage, that requires to highlight the relationships between environmental impact of their processes and company strategy and objectives. The methodology is presented by means of a real-world case concerning the IER of a large aluminium alloy foundry.
Some categorical aspects of BCH‐algebras
Authors: Chaudhry Muhammad Anwar , Fakhar-ud-din Hafiz
Published: May 2003

We show that the category BCH of BCH‐algebras and
BCH‐homomorphisms is complete. We also show that it has
coequalizers, kernel pairs, and an image factorization system. It
is also proved that onto homomorphisms and coequalizers, and
monomorphisms and one‐to‐one homomorphisms coincide,
respectively, in BCH. It is shown that MBCI is a coreflexive
subcategory of BCH. Regular homomorphisms have been defined and
their properties are studied. An open problem has been posed.
Nonlinear peristaltic transport of MHD flow through a porous medium
Authors: Mekheimer Kh. S. , Al-Arabi T. H.
Published: May 2003

In order to determine the characteristics of peristaltic
transport of magnetohydrodynamic flow through a porous medium,
the motion of a hydromagnetic (electrically conducting), viscous,
and incompressible fluid in planer channel filled with a
homogeneous porous medium and having electrically insulated walls
that are transversely displaced by an infinite, harmonic
travelling wave of large wavelength was analyzed using a
perturbation expansion in terms of a variant wave number. We
obtain an explicit form for the velocity field, a relation between
the pressure rise and flow rate, in terms of Reynolds number,
wave number, Hartmann number, permeability parameter, and the
occlusion. The effects of all parameters of the problem are
numerically discussed and graphically explained.
B.‐Y. Chen inequalities for semislant submanifolds in Sasakianspace forms
Authors: Cioroboiu Dragoş
Published: May 2003

Chen (1993) established a sharp inequality for the sectional
curvature of a submanifold in Riemannian space forms in terms of
the scalar curvature and squared mean curvature. The notion of a
semislant submanifold of a Sasakian manifold was introduced by J.
L. Cabrerizo, A. Carriazo, L. M. Fernandez, and M. Fernandez
(1999). In the present paper, we establish Chen inequalities for
semislant submanifolds in Sasakian space forms by using subspaces
orthogonal to the Reeb vector field ξ.
On the prime submodules of multiplication modules
Authors: Ameri Reza
Published: May 2003

By considering the notion of multiplication modules over a
commutative ring with identity, first we introduce the notion
product of two submodules of such modules. Then we use this
notion to characterize the prime submodules of a multiplication
module. Finally, we state and prove a version of Nakayama lemma
for multiplication modules and find some related basic results.
An application of a subordination chain
Authors: Singh Sukhjit , Gupta Sushma
Published: May 2003

Let K denote the class of functions g(z) = z + a2z2 + ⋯ which are regular and univalently convex in the unit disc E. In the present note, we prove that if f is regular in E, f(0) = 0, then for g ∈ K, f(z) + αzf′(z) ≺ g(z) + αzg′(z) in E implies that f(z)≺g(z) in E, where α > 0 is a real number and the symbol “≺” stands for
subordination.
The Kneser property for abstract retarded functional differentialequations with infinite delay
Authors: Henríquez Hernán R.
Published: May 2003

We establish existence of mild solutions for a class of
semilinear first‐order abstract retarded functional differential
equations (ARFDEs) with infinite delay and we prove
that the set consisting of mild solutions for this problem is
connected in the space of continuous functions.
Time‐symmetric cycles
Authors: Bernhardt Chris
Published: May 2003

The main result of this note is that given any two time‐symmetric
cycles, one can find a time‐symmetric extension of one by the
other. This means that given a time‐symmetric cycle, both
time‐symmetric doubles and square roots can be found.
On some new properties of the spherical curvature ofstereographically projected analytic curves
Authors: Zemyan Stephen M.
Published: May 2003

We discover new information about the spherical curvature of
stereographically projected analytic curves. To do so, we first
state formulas for the spherical curvature and spherical torsion
of the curves on S2 which result after stereographically
projecting the image curves of analytic, univalent functions
belonging to the class 𝒮. We then derive results
concerning the location of the critical points of the spherical
curvature, considered both as a function of one and two
variables. Further analysis leads to a maximum principle for the
spherical curvature functions.
Duality in the optimal control for damped hyperbolic systems with positive control
Authors: Lee Mi Jin , Park Jong Yeoul , Kwon Young Chel
Published: May 2003

We study the duality theory for damped hyperbolic equations.
These systems have positive controls and convex cost functionals. Our main results lie in the application of duality theorem, that is, inf J = sup K, on various cost functions.
On Hopf DeMeyer‐Kanzaki Galois extensions
Authors: Szeto George , Xue Lianyong
Published: May 2003

Let H be a finite‐dimensional Hopf algebra over a field k, B a left H‐module algebra, and H∗ the dual Hopf algebra of H. For an H∗‐Azumaya Galois extension B with center C, it is shown that B is an H∗‐DeMeyer‐Kanzaki Galois extension if
and only if C is a maximal commutative separable subalgebra of
the smash product B#H. Moreover, the characterization of a commutative Galois algebra as given by S. Ikehata (1981) is generalized.
Synge‐Beil and Riemann‐Jacobi jet structures with applications to physics
Authors: Balan Vladimir
Published: May 2003

In the framework of geometrized first‐order jet approach, we
study the Synge‐Beil generalized Lagrange jet structure, derive the canonic nonlinear and Cartan connections, and infer the Einstein‐Maxwell equations with sources; the classical ansatz is emphasized as a particular case. The Lorentz‐type equations are described and the attached Riemann‐Jacobi structures for two certain uniparametric cases are presented.
Shear Stress Is Differentially Regulated Among Inbred Rat Strains
Authors: Ibrahim Jamila , Miyashiro Jody K. , Berk Bradford C.
Published: May 2003

An important compensatory response to atherosclerosis is vascular remodeling, with maintenance of vessel lumen diameter and shear stress. Both hemodynamic and environmental factors contribute to vascular remodeling and shear stress regulation, and the process is probably also influenced by genetic factors. To establish an animal model for genetic analysis of shear stress regulation and vascular remodeling, we studied the effects of chronic flow alteration in four inbred rat strains. By ligating the left internal and external carotid arteries, we caused a ≈90% decrease in left common carotid blood flow and a ≈50% increase in right (contralateral) common carotid flow. After 4 weeks of altered flow, there were significant interstrain differences with respect to the change in carotid outer diameter (OD), the relationship between flow and shear stress, and the extent to which shear stress was normalized. Genetically hypertensive rats (GH) exhibited the greatest reduction in shear stress in response to increased flow, stroke-prone spontaneously hypertensive rats (SHR-SP) exhibited a smaller response, and Brown Norway (BN) rats exhibited the smallest response. SHR-SP and GH also differed significantly in outward remodeling (defined as an increase in lumen and vessel diameter) in increased flow arteries. In response to decreased flow, BN rats exhibited the smallest reduction in shear stress. These findings demonstrate significant strain-dependent differences in shear stress regulation and vascular remodeling in response to altered flow. This study emphasizes the important role of genetic factors in vascular remodeling and suggests that genetic analysis of these strains will provide novel insights into the underlying mechanisms.
HMG-CoA Reductase Inhibitors Reduce Senescence and Increase Proliferation of Endothelial Progenitor Cells via Regulation of Cell Cycle Regulatory Genes
Authors: Assmus Birgit , Urbich Carmen , Aicher Alexandra , Hofmann Wolf K. , Haendeler Judith , Rössig Lothar , Spyridopoulos Ioakim , Zeiher Andreas M. , Dimmeler Stefanie
Published: May 2003

Endothelial progenitor cells (EPCs) play an important role in postnatal neovascularization of ischemic tissue. Ex vivo expansion of EPCs might be useful for potential clinical cell therapy of myocardial ischemia. However, cultivation of primary cells leads to cellular aging (senescence), thereby severely limiting the proliferative capacity. Therefore, we investigated whether statins might be able to prevent senescence of EPCs. EPCs were isolated from peripheral blood and characterized. After ex vivo cultivation, EPCs became senescent as determined by acidic β-galactosidase staining. Atorvastatin or mevastatin dose-dependently inhibited the onset of EPC senescence in culture. Moreover, atorvastatin increased proliferation of EPCs as assessed by BrdU incorporation and colony-forming capacity. Whereas geranylgeranylpyrophosphate or farnesylpyrophosphate reduced the senescence inhibitory effect of atorvastatin, NO synthase inhibition, antioxidants, or Rho kinase inhibitors had no effect. To get further insights into the underlying downstream effects of statins, we measured telomerase activity and determined the expression of various cell cycle regulatory genes by using a microarray assay. Whereas telomerase activity did not change, atorvastatin modulated expression of cell cycle genes including upregulation of cyclins and downregulation of the cell cycle inhibitor p27
Kip1
. Taken together, statins inhibited senescence of EPCs independent of NO, reactive oxygen species, and Rho kinase, but dependent on geranylgeranylpyrophosphate. Atorvastatin-mediated prevention of EPC senescence appears to be mediated by the regulation of various cell cycle proteins. The inhibition of EPC senescence and induction of EPC proliferation by statins in vitro may importantly improve the functional activity of EPCs for potential cell therapy.
Molecular Variants of KCNQ Channels Expressed in Murine Portal Vein Myocytes
Authors: Ohya Susumu , Sergeant Gerard P. , Greenwood Iain A. , Horowitz Burton
Published: May 2003

We have analyzed the expression of KCNQ genes in murine portal vein myocytes and determined that of the 5 known KCNQ channels, only KCNQ1 was expressed. In addition to the full-length KCNQ1 transcript, a novel spliced form (termed KCNQ1b) was detected that had a 63 amino acid truncation at the C-terminus. KCNQ1b was not detected in heart or brain but represented approximately half the KCNQ1 transcripts expressed in PV. Antibodies specific for KCNQ1a stained cell membranes from portal vein myocytes and HEK cells expressing the channel. However, because the antibodies were generated against an epitope in the deleted, C-terminal portion of the protein, these antibodies did not stain HEK cells expressing KCNQ1b. In murine portal vein myocytes, in the presence of 5 mmol/L 4-aminopyridine, an outwardly rectifying K
+
current was recorded that was sensitive to linopirdine, a specific blocker of KCNQ channels. Currents produced by the heterologous expression of KCNQ1a or KCNQ1b were inhibited by similar concentrations of linopirdine, and linopirdine prolonged the time-course of the action potential in isolated portal vein myocytes. Our data suggest that these two KCNQ1 splice forms are expressed in murine portal vein and contribute to the delayed rectifier current in these myocytes.
Chronic Hypoxia Activates Lung 15-Lipoxygenase, Which Catalyzes Production of 15-HETE and Enhances Constriction in Neonatal Rabbit Pulmonary Arteries
Authors: Zhu Daling , Medhora Meetha , Campbell William B. , Spitzbarth Nancy , Baker John E. , Jacobs Elizabeth R.
Published: May 2003

Hypoxia causes localized pulmonary arterial (PA) constriction to divert blood flow to optimally ventilated regions of the lung. The biochemical mechanisms for this have remained elusive, especially during prolonged exposures to reduced P
o
2
. We have evidence that subacute hypoxia activates 15-lipoxygenase (15-LO) in small PAs of neonatal rabbits maintained for 9 days in hypoxic environments (F
io
2
=0.12) compared with siblings raised under normoxia. PA microsomal products of 15-LO, 15-hydroxyeicosatetraenoic acid (HETE), 11,14,15-trihydroxyeicosatrienoic acid (THETA), and 11,12,15-THETA were identified by gas chromatography/mass spectrometry. Increased amounts of these products are synthesized in vivo and in vitro by the lungs of animal raised in hypoxic versus normoxic environments. 15-HETE formation is attenuated by lipoxygenase, but not cytochrome P450 or cyclooxygenase inhibitors. Activation of 15-LO is associated with translocation of the enzyme from the cytosol to membrane as seen by Western immunoblotting. Immunohistochemical analysis demonstrates that 15-LO expression is clearly localized in vascular cells in lungs from normoxic and hypoxic kits. 15-HETE causes concentration-dependent constriction of PA rings from animals exposed to hypoxic but not normoxic environments. In addition, lipoxygenase inhibitors reduce phenylephrine-induced constriction of PA rings. Therefore, subacute hypoxia increases expression of and activates 15-LO, and enhances sensitivity of pulmonary arteries to its product, 15-HETE. Because 15-HETE is a constrictor in this vascular bed, it may play an important role in hypoxia-induced pulmonary vasoconstriction in rabbit kits. Although a clear causal relationship remains to be demonstrated, these data suggest a previously unrecognized role for 15-LO in hypoxic vasoconstriction in neonatal mammals.
Cardiac Submembrane [Na
+
] Transients Sensed by Na
+
-Ca
2+
Exchange Current
Authors: Weber Christopher R. , Ginsburg Kenneth S. , Bers Donald M.
Published: May 2003

Na
+
influx via
I
Na
during cardiac action potentials can raise bulk [Na
+
]
i
by 10 to 15 μmol/L. However, larger rises in submembrane [Na
+
] ([Na
+
]
sm
) local to Na
+
-Ca
2+
exchangers (NCX) could enhance Ca
2+
influx via NCX (and Ca
2+
-induced Ca
2+
release). We tested whether
I
Na
could increase [Na
+
]
sm
, using NCX current (
I
NCX
) as a biosensor in rabbit ventricular myocytes (with [Ca
2+
]
i
buffered, [Na
+
]
i
=10 mmol/L, and other currents blocked). We measured
I
NCX
as early as 5 ms after
I
Na
. Prior
I
Na
activation did not affect
I
NCX
at physiological membrane potentials (E
m
=−100 to +50 mV), but for E
m
>+50 mV (where
I
NCX
is especially sensitive to [Na
+
]
i
),
I
NCX
shifted outward. At 5 ms and +100 mV,
I
Na
shifted
I
NCX
outward by 0.23 A/F (corresponding to Δ[Na
+
]
sm
=0.24 mmol/L). The effect of
I
Na
dissipated with a time constant of ≈15 ms. Thus, the impact of
I
Na
on NCX is almost undetectable at physiological E
m
and short lived. This suggests that
I
Na
effects on excitation-contraction coupling (via outward
I
NCX
) are minimal and limited to early during the action potential. However, local Δ[Na
+
]
sm
during
I
Na
may be 60 times higher than bulk Δ[Na
+
]
i
.
Organelle Proteomics
Authors: Huber Lukas A. , Pfaller Kristian , Vietor Ilja
Published: May 2003

Functional proteome analysis is not restricted to the sequence information but includes the broad spectrum of structural modifications and quantitative changes of proteins to which they are subjected in different tissues and cell organelles and during the development of an organism. Cell biology has provided the means required for the analysis of the composition and properties of purified cellular elements. Subcellular fractionation is an approach universal across all cell types and tissues, including cardiac and vascular system. Subcellular fractionation and proteomics form an ideal partnership when it comes to enrichment and analysis of intracellular organelles and low abundant multiprotein complexes. Subcellular fractionation is a flexible and adjustable approach resulting in reduced sample complexity and is most efficiently combined with high-resolution 2D gel/mass spectrometry analysis as well as with gel-independent techniques. In this study we introduce state of the art subcellular fractionation techniques and discuss their suitability, advantages, and limitations for proteomics research.
Epistemic Containment
Authors: Fintel Kai von , Iatridou Sabine
Published: May 2003

This article concerns a new constraint on the interaction of quantifier phrases and epistemic modals. It is argued that QPs cannot bind their traces across an epistemic modal, though it is shown that scoping mechanisms of a different nature are permitted to cross epistemic modals. The nature and source of this constraint are investigated.
Deriving the Feature-Filling/Feature-Changing Contrast: An Application to Hungarian Vowel Harmony
Authors: Reiss Charles
Published: May 2003

The article explores an alternative to the interpretive procedure adopted in SPE and proposes a unified interpretive procedure for all languages. The proposal solves long-standing problems by making it unnecessary to refer to a third value of binary features [θF], to introduce negation into lexical representations (e.g., [NOT + rd]), or to introduce a feature filling/feature changing diacritic on rules.The article provides a metric for comparing extensionally equivalent rule systems and argues that the most concise formulation is not always the correct one, by appealing to crosslinguistic evidence.The proposal is illustrated by application to the target/trigger relations in Hungarian vowel harmony.
Optimal Tone Mapping
Authors: Zoll Cheryl
Published: May 2003

Traditional autosegmental accounts of tone mapping invoke three independent factors: morphological category, tone quality, and a phonological directionality parameter. This article argues that the evidence for phonological directionality must be reconsidered. The article introduces a theory of Optimal Tone Mapping, in which attested patterns derive solely from the interaction of morphological directionality with quality-sensitive markedness constraints. The more restrictive theory of tone association that results from eliminating constraints that impose phonological directionality provides a new typology of tone melody languages.
Reply to “Control Is Not Movement”
Authors: Boeckx Cedric , Hornstein Norbert
Published: May 2003

In this reply we examine Culicover and Jackendoff's (2001) arguments against syntactic treatments of control, and against Hornstein 1999 in particular. We focus on three of their core arguments: (a) the syntactocentric view of control; (b) the control pattern found with promise; and (c) the violability of the Minimal Distance Principle. In all cases we contend that Culicover and Jackendoff's claims fail to undermine Hornstein's proposal.
Estimating a State-Space Model from Point Process Observations
Authors: Smith Anne C. , Brown Emery N.
Published: May 2003

A widely used signal processing paradigm is the state-space model. The state-space model is defined by two equations: an observation equation that describes how the hidden state or latent process is observed and a state equation that defines the evolution of the process through time. Inspired by neurophysiology experiments in which neural spiking activity is induced by an implicit (latent) stimulus, we develop an algorithm to estimate a state-space model observed through point process measurements. We represent the latent process modulating the neural spiking activity as a gaussian autoregressive model driven by an external stimulus. Given the latent process, neural spiking activity is characterized as a general point process defined by its conditional intensity function. We develop an approximate expectation-maximization (EM) algorithm to estimate the unobservable state-space process, its parameters, and the parameters of the point process. The EM algorithm combines a point process recursive nonlinear filter algorithm, the fixed interval smoothing algorithm, and the state-space covariance algorithm to compute the complete data log likelihood efficiently. We use a Kolmogorov-Smirnov test based on the time-rescaling theorem to evaluate agreement between the model and point process data. We illustrate the model with two simulated data examples: an ensemble of Poisson neurons driven by a common stimulus and a single neuron whose conditional intensity function is approximated as a local Bernoulli process.
Sequential Bayesian Decoding with a Population of Neurons
Authors: Wu Si , Chen Danmei , Niranjan Mahesan , Amari Shun-ichi
Published: May 2003

Population coding is a simplified model of distributed information processing in the brain. This study investigates the performance and implementation of a sequential Bayesian decoding (SBD) paradigm in the framework of population coding. In the first step of decoding, when no prior knowledge is available, maximum likelihood inference is used; the result forms the prior knowledge of stimulus for the second step of decoding. Estimates are propagated sequentially to apply maximum a posteriori (MAP) decoding in which prior knowledge for any step is taken from estimates from the previous step. Not only do we analyze the performance of SBD, obtaining the optimal form of prior knowledge that achieves the best estimation result, but we also investigate its possible biological realization, in the sense that all operations are performed by the dynamics of a recurrent network. In order to achieve MAP, a crucial point is to identify a mechanism that propagates prior knowledge. We find that this could be achieved by short-term adaptation of network weights according to the Hebbian learning rule. Simulation results on both constant and time-varying stimulus support the analysis.
Learning Coefficients of Layered Models When the True Distribution Mismatches the Singularities
Authors: Watanabe Sumio , Amari Shun-ichi
Published: May 2003

Hierarchical learning machines such as layered neural networks have singularities in their parameter spaces. At singularities, the Fisher information matrix becomes degenerate, with the result that the conventional learning theory of regular statistical models does not hold. Recently, it was proved that if the parameter of the true distribution is contained in the singularities of the learning machine, the generalization error in Bayes estimation is asymptotically equal toλ/n, where 2λ is smaller than the dimension of the parameter andn is the number of training samples. However, the constantλ strongly depends on the local geometrical structure of singularities; hence, the generalization error is not yet clarified when the true distribution is almost but not completely contained in the singularities. In this article, in order to analyze such cases, we study the Bayes generalization error under the condition that the Kullback distance of the true distribution from the distribution represented by singularities is in proportion to 1/n and show two results. First, if the dimension of the parameter from inputs to hidden units is not larger than three, then there exists a region of true parameters such that the generalization error is larger than that of the corresponding regular model. Second, if the dimension from inputs to hidden units is larger than three, then for arbitrary true distribution, the generalization error is smaller than that of the corresponding regular model.
Gamma Rhythmic Bursts: Coherence Control in Networks of Cortical Pyramidal Neurons
Authors: Aoyagi Toshio , Takekawa Takashi , Fukai Tomoki
Published: May 2003

Much evidence indicates that synchronized gamma-frequency (20–70 Hz) oscillation plays a significant functional role in the neocortex and hippocampus. Chattering neuron is a possible neocortical pacemaker for the gamma oscillation. Based on our recent model of chattering neurons, here we study how gamma-frequency bursting is synchronized in a network of these neurons. Using a phase oscillator description, we first examine how two coupled chattering neurons are synchronized. The analysis reveals that an incremental change of the bursting mode, such as from singlet to doublet, always accompanies a rapid transition from antisynchronous to synchronous firing. The state transition occurs regardless of what changes the bursting mode. Within each bursting mode, the neuronal activity undergoes a gradual change from synchrony to antisynchrony. Since the sensitivity to Ca2+ and the maximum conductance of Ca2+ -dependent cationic current as well as the intensity of input current systematically control the bursting mode, these quantities may be crucial for the regulation of the coherence of local cortical activity. Numerical simulations demonstrate that the modulations of the calcium sensitivity and the amplitude of the cationic current can induce rapid transitions between synchrony and asynchrony in a large-scale network of chattering neurons. The rapid synchronization of chattering neurons is shown to synchronize the activities of regular spiking pyramidal neurons at the gamma frequencies, as may be necessary for selective attention or binding processing in object recognition.
Manhattan World: Orientation and Outlier Detection by Bayesian Inference
Authors: Coughlan James M. , Yuille A. L.
Published: May 2003

This letter argues that many visual scenes are based on a “Manhattan” three-dimensional grid that imposes regularities on the image statistics. We construct a Bayesian model that implements this assumption and estimates the viewer orientation relative to the Manhattan grid. For many images, these estimates are good approximations to the viewer orientation (as estimated manually by the authors). These estimates also make it easy to detect outlier structures that are unaligned to the grid. To determine the applicability of the Manhattan world model, we implement a null hypothesis model that assumes that the image statistics are independent of any three-dimensional scene structure. We then use the log-likelihood ratio test to determine whether an image satisfies the Manhattan world assumption. Our results show that if an image is estimated to be Manhattan, then the Bayesian model's estimates of viewer direction are almost always accurate (according to our manual estimates), and vice versa.
Kernel-Based Nonlinear Blind Source Separation
Authors: Harmeling Stefan , Ziehe Andreas , Kawanabe Motoaki , Müller Klaus-Robert
Published: May 2003

We propose kTDSEP, a kernel-based algorithm for nonlinear blind source separation (BSS). It combines complementary research fields: kernel feature spaces and BSS using temporal information. This yields an efficient algorithm for nonlinear BSS with invertible nonlinearity. Key assumptions are that the kernel feature space is chosen rich enough to approximate the nonlinearity and that signals of interest contain temporal information. Both assumptions are fulfilled for a wide set of real-world applications. The algorithm works as follows: First, the data are (implicitly) mapped to a high (possibly infinite)—dimensional kernel feature space. In practice, however, the data form a smaller submanifold in feature space—even smaller than the number of training data points—a fact that has already been used by, for example, reduced set techniques for support vector machines. We propose to adapt to this effective dimension as a preprocessing step and to construct an orthonormal basis of this submanifold. The latter dimension-reduction step is essential for making the subsequent application of BSS methods computationally and numerically tractable. In the reduced space, we use a BSS algorithm that is based on second-order temporal decorrelation. Finally, we propose a selection procedure to obtain the original sources from the extracted nonlinear components automatically.

Experiments demonstrate the excellent performance and efficiency of our kTDSEP algorithm for several problems of nonlinear BSS and for more than two sources.
An Algorithm of Supervised Learning for Multilayer Neural Networks
Authors: Tang Zheng , Wang Xu Gang , Tamura Hiroki , Ishii Masahiro
Published: May 2003

A method of supervised learning for multilayer artificial neural networks to escape local minima is proposed. The learning model has two phases: a backpropagation phase and a gradient ascent phase. The backpropagation phase performs steepest descent on a surface in weight space whose height at any point in weight space is equal to an error measure, and it finds a set of weights minimizing this error measure. When the backpropagation gets stuck in local minima, the gradient ascent phase attempts to fill up the valley by modifying gain parameters in a gradient ascent direction of the error measure. The two phases are repeated until the network gets out of local minima. The algorithm has been tested on benchmark problems, such as exclusive-or (XOR), parity, alphabetic characters learning, Arabic numerals with a noise recognition problem, and a realistic real-world problem: classification of radar returns from the ionosphere. For all of these problems, the systems are shown to be capable of escaping from the backpropagation local minima and converge faster when using the new proposed method than using the simulated annealing techniques.
The Time-Organized Map Algorithm: Extending the Self-Organizing Map to Spatiotemporal Signals
Authors: Wiemer Jan C.
Published: May 2003

The new time-organized map (TOM) is presented for a better understanding of the self-organization and geometric structure of cortical signal representations. The algorithm extends the common self-organizing map (SOM) from the processing of purely spatial signals to the processing of spatiotemporal signals. The main additional idea of the TOM compared with the SOM is the functionally reasonable transfer of temporal signal distances into spatial signal distances in topographic neural representations. This is achieved by neural dynamics of propagating waves, allowing current and former signals to interact spatiotemporally in the neural network. Within a biologically plausible framework, the TOM algorithm (1) reveals how dynamic neural networks can self-organize to embed spatial signals in temporal context in order to realize functional meaningful invariances, (2) predicts time-organized representational structures in cortical areas representing signals with systematic temporal relation, and (3) suggests that the strength with which signals interact in the cortex determines the type of signal topology realized in topographic maps (e.g., spatially or temporally defined signal topology). Moreover, the TOM algorithm supports the explanation of topographic reorganizations based on time-to-space transformations (Wiemer, Spengler, Joublin, Stagge, & Wacquant, 2000).
New Conditions on Global Stability of Cohen-Grossberg Neural Networks
Authors: Lu Wenlian , Chen Tianping
Published: May 2003

In this letter, we discuss the dynamics of the Cohen-Grossberg neural networks. We provide a new and relaxed set of sufficient conditions for the Cohen-Grossberg networks to be absolutely stable and exponentially stable globally. We also provide an estimate of the rate of convergence.
Initial antibiotic therapy for lower respiratory tract infection in the community: a European survey
Authors: Huchon GJ , Gialdroni-Grassi G , Leophonte P , Manresa F , Schaberg T , Woodhead M
Published: May 2003

A survey of first-line antibiotic prescription in community-acquired lower respiratory tract infection (LRTI) by general practitioners (GP) was carried out simultaneously, using the same methodology in France, Germany, Italy, Spain and the UK. Data were obtained from 2,056 patients and 605 GPs. There was no antibiotic prescription in 17% of all LRTIs and 13% of community-acquired pneumonia (CAP) in the five countries taken together; and in 32% of all LRTIs and in 23% of CAP in Germany. Of patients with acute bronchitis, exacerbation of chronic bronchitis and viral lower respiratory tract infection, 87, 92 and 71% received antibiotics, respectively. The most frequent prescriptions were penicillins in France and the UK, third-generation cephalosporin in Italy, tetracycline in Germany and macrolide in Spain. The daily dosage of aminopenicillin prescribed was: 41% <1.5 g; 49% > or = 1.5 g and <3 g; and 10% > or = 3 g. In Italy, 53% of all antibiotics were injected in all LRTIs, and 71% in CAP; in contrast, antibiotic injection was lower than 2% both in the UK and Germany, with an average of 14% in the five countries combined. We conclude that there are variations in antibiotic prescription by GPs in Western Europe; differences are likely to be multifactorial, but could, in part, be explained by differences in health systems and sources of information available to GPs.
Use of investigations in lower respiratory tract infection in the community: a European survey
Authors: Woodhead M , Gialdroni Grassi G , Huchon GJ , Leophonte P , Manresa F , Schaberg T
Published: May 2003

A questionnaire survey was performed on the use of investigations and their impact on treatment of adult lower respiratory tract infection in the community. Data on the management of 2,056 such infections were obtained simultaneously from general practitioners in France, Germany, Italy, Spain and the UK. Diagnostic tests were only performed in 29% of cases. Chest radiographs were performed most frequently (22%), followed by peripheral blood white cell count (15%) and microbiological examination of sputum (7%), with major differences being found in the frequency of these tests both by clinical diagnosis and country. A change in initial antibiotic therapy was made in 12% of cases, with use of investigation being significantly linked to such changes. Second- and third-line antibiotics were significantly different to first-line therapy, with macrolides the most frequently prescribed second-line and quinolones the most frequently prescribed third-line antibiotics.
Lung function in bronchiectasis: the influence of Pseudomonas aeruginosa
Authors: Evans SA , Turner SM , Bosch BJ , Hardy CC , Woodhead MA
Published: May 2003

Sputum isolation of Pseudomonas aeruginosa (PA) is associated with extensive disease in bronchiectasis. It is not known, however, whether infection with P. aeruginosa is the result or the cause of severe disease. We compared spirometry in patients with bronchiectasis before and after infection with P. aeruginosa, with that of patients infected by other organisms. All patients (n=12) with chronic colonization by P. aeruginosa (PA group) were studied. These were compared with other patients with bronchiectasis with no isolations of P. aeruginosa (n=37, non-PA group). In the PA group, forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were lower than in the non-PA group. The PA group, however, also had lower values at the time of initial colonization with P. aeruginosa than the current values for the non-PA group. Change in FEV1 and FVC over time was faster in the PA group than in the non-PA group. Reduction of FEV1 and FVC over time in the PA group prior to P. aeruginosa colonization was intermediate, not being statistically different from either value above. Our results confirm the association of chronic P. aeruginosa colonization with poor lung function, but conclude that patients with bronchiectasis who become colonized by P. aeruginosa have poorer lung function when first colonized than those colonized by other organisms. Decline in lung function is faster in those chronically colonized by P. aeruginosa than in those colonized by other organisms. It is not clear whether chronic P. aeruginosa colonization causes an accelerated decline in lung function or whether it is simply a marker of those whose lung function is already declining rapidly.
Long-term home care programmes may reduce hospital admissions in COPD with chronic hypercapnia
Authors: Clini E , Vitacca M , Foglio K , Simoni P , Ambrosino N
Published: May 2003

Long-term oxygen therapy (LTOT) has been shown to improve survival in chronic obstructive pulmonary disease (COPD) patients. The clinical effectiveness of long-term home mechanical ventilation (HMV) is still discussed, nevertheless both LTOT and HMV are often included in the home care programmes of these patients. To evaluate the effectiveness of home care programmes including either HMV or LTOT, 34 COPD patients were studied. They were admitted to either HMV (Group A: 12 males and 5 females, aged 62 +/- 5 yrs), or LTOT (Group B: 9 males and 8 females, aged 62 +/- 8 yrs). They were compared to a historical group (Group C: 19 males and 10 females, aged 67 +/- 16 yrs) performing only their usual standard LTOT during the same period. Spirometry, maximal inspiratory pressure and arterial blood gas values were assessed at baseline and at 6, 12 and 18 months of follow-up. Mortality rate and number of hospital and intensive care unit (ICU) admissions and days of hospitalization were also assessed. Four out of 17 (23%) patients in Group A, 3 out of 17 (18%) in Group B, and 5 out of 29 (17%) in Group C died within 18 months. Of the lung function tests, only maximal inspiratory pressure in Group A showed a significant increase in the 18th month (50 +/- 4 to 56 +/- 7 cmH2O; p<0.01). In comparison to 18 months prior to the study, hospital admissions (from 2.2 +/- 0.6 to 1.3 +/- 1.1 and from 2.0 +/- 0.7 to 1.0 +/- 0.9 for Group A and B, respectively; p<0.005 for both), and days of hospitalization (from 60 +/- 34 to 34 +/- 40 and from 55 +/- 23 to 18 +/- 20 days in Group A and B, respectively; p<0.005 for both) significantly decreased only in the two groups submitted to the home care programme. We conclude that home care programmes may be effective in the long-term treatment of chronically hypercapnic chronic obstructive pulmonary disease patients in reducing hospital admissions.
Upper airway size and collapsibility in snorers: evaluation with digital fluoroscopy
Authors: Tsushima Y , Antila J , Svedstrom E , Vetrio A , Laurikainen E , Polo O , Kormano M
Published: May 2003

This study addressed the question of whether there are any differences in the size and collapsibility of the upper airway measured by digital fluoroscopy, between snorers and controls whilst they were awake and breathing normally; and whether there are any correlations between these measurements and other clinical data. The dynamic changes of the upper airway size were evaluated using digital fluoroscopy in 33 patients and 16 normal controls. The measurements were compared with findings in an overnight sleep study, including a static-charge-sensitive bed (SCSB) and oximeter recordings. The minimum anteroposterior dimension at the velopharyngeal level was smaller in patients with partial upper airway obstruction than in controls (p<0.005); patients with complete obstruction did not differ from the controls. The velopharyngeal airways were also more collapsible in patients with severe partial obstruction (p<0.01) than in controls. At the oropharyngeal and hypopharyngeal levels, the dimensions and the collapsibilities were similar in patients and controls. The velopharyngeal collapsibility correlated with body mass index (p<0.001), whereas the airway size did not. The velopharyngeal collapsibility was more pronounced in patients with frequent episodes of arterial oxyhaemoglobin desaturation during sleep. Velopharyngeal collapsibility associated with high body mass index was the important determinant of nocturnal breathing disturbances. Digital fluoroscopy displays the dynamic changes of the upper airways throughout the respiratory cycle.
Recycling of hard-core smokers with nicotine nasal spray
Authors: Tonnesen P , Mikkelsen K , Norregaard J , Jorgensen S
Published: May 2003

The primary aim of this smoking cessation study was to evaluate the effect of long-term treatment with nicotine nasal spray in a group of hard-core smokers. A further aim was to compare the effect of ad libitum with fixed dosage of nasal nicotine spray. Eighty nine smokers, failures from two earlier studies with nicotine patches, were enrolled in an open smoking cessation study with nicotine nasal sprays, to be used ad libitum (n=45) or on a fixed schedule of 1 mg x h-1 during the day (n= 44). Carbon monoxide-verified continuous abstinence from smoking beyond Week 2, was 39% at 3 weeks, 12% at 3 months, 10% at 6 months and 6% after 1 yr, with no significant difference in success rate between ad libitum and fixed dosing. Mean daily nicotine dose was 15-16 mg during the first 3 months (range 2-65 mg). Tolerance to local irritating side-effects of nicotine developed during the first weeks of use. Although short-term outcome was promising, the long-term success rate in this group of hardcore smokers was low. Other recycling set-ups are warranted, which might include more aggressive nicotine dosing.
Female gender as a determinant of cough threshold to inhaled capsaicin
Authors: Fujimura M , Kasahara K , Kamio Y , Naruse M , Hashimoto T , Matsuda T
Published: May 2003

Chronic, nonproductive cough and cough associated with the use of angiotensin converting enzyme inhibitors, are more frequently observed in females as compared to males. To examine the influence of sex, age, height, weight and pulmonary function on airway cough sensitivity, cough threshold to inhaled capsaicin, an index of the airway cough sensitivity, was measured in 160 nonsmoking, nonatopic healthy subjects. Forty young males (aged 24 +/- 2 yrs) 40 young females (aged 22 +/- 2 yrs) 40 middle-aged males (aged 48 +/- 5 yrs) and 40 middle-aged females (aged 50 +/- 7 yrs) were studied. The cough threshold was defined as the lowest concentration of inhaled capsaicin causing five or more coughs. The cough threshold was 3-5 fold lower in females than in males both in young (p<0.001) and middle-aged (p<0.005) subjects. Cough threshold was weakly but significantly correlated to height, weight, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) when all subjects were considered together but not when each group was considered separately. Multiple regression analysis revealed that sex difference was the significant predictive factor for the cough threshold in either age group. These results confirm that cough sensitivity is heightened in females and suggest that influence of height and pulmonary function on the cough threshold may have resulted from sex difference.
Effect of cessation of short-term therapy with ipratropium bromide on lung function and airway responsiveness
Authors: Wilding PJ , Clark MM , Pavord ID , Parker D , Bennett JA , Tattersfield AE
Published: May 2003

Regular exposure to antimuscarinic drugs would be expected to upregulate airway muscarinic receptors and could cause a transient increase in airways obstruction if treatment was stopped or omitted. We have examined peak expiratory flow rate (PEFR) during treatment and forced expiratory flow in one second (FEV1) and airway responsiveness to three constrictor agonists (as the provocative dose of agonist causing a 20% fall in FEV1, (PD20)) following cessation of regular inhaled ipratropium bromide, in 13 subjects with mild stable asthma. Subjects inhaled placebo and ipratropium bromide, 80 microg q.i.d. for 14 days in a cross-over fashion with a 1 week run-in/wash-out period before and after each treatment period. Subjects recorded symptom scores and PEFR throughout the study, and FEV1 and PD20 to histamine, methacholine and metabisulphite were measured before and after cessation of treatment. When compared to baseline, FEV1 was lower after cessation of ipratropium than after placebo, with a significant difference 30 h after the last dose (difference 190 mL; 95% confidence interval (95% CI) 310-70 mL; p<0.02). FEV1 measured 6-10 days later, did not differ significantly. PEFR was significantly lower after cessation of ipratropium than after placebo on Day 15 (19-37 h after the last dose) (mean difference 4.6%; 95% CI 1.6-7.5%; p<0.01) but not on Day 16. There were no significant changes in PD20 histamine, methacholine and metabisulphite, symptom scores or rescue bronchodilator use after cessation of treatment. Thus, transient bronchoconstriction was found around 30 h after cessation of regular therapy with inhaled ipratropium for 2 weeks. The mechanism is unclear, as no evidence of muscarinic receptor upregulation was found. Although the changes were small and unlikely to be important for most patients, the results of this study indicate that the timing of lung function measurements relative to the last dose of ipratropium is important when interpreting the course of lung function in long-term studies.