bluuebunny/crossref_metadata_2025 huggingface dataset:
A proof of the Hoggatt-Bergum conjecture
Authors: Dujella Andrej
Published: November 2002

It is proved that ifkkandddare positive integers such that the product of any two distinct elements of the set\[{F2k,F2k+2,F2k+4,d}\{F_{2k},\, F_{2k+2},\, F_{2k+4},\, d\}\]increased by11is a perfect square, thenddhas to be4F2k+1F2k+2F2k+34F_{2k+1}F_{2k+2}F_{2k+3}. This is a generalization of the theorem of Baker and Davenport fork=1k=1.
Uniform distribution modulo one on subsequences
Authors: Hill Chris
Published: November 2002

Let

P

\mathcal {P}

be a set of primes with a divergent series of reciprocals and let

K

=

K

(

P

)

\mathcal {K} = \mathcal {K}(\mathcal {P} )

denote the set of squarefree integers greater than one that are divisible only by primes in

P

\mathcal {P}

. G. Myerson and A. D. Pollington proved that

(

u

n

)

n
≥
1

⊂
[
0
,
1
)

(u_{n})_{n\geq 1}\subset [0,1)

is uniformly distributed (mod 1) whenever the subsequence

(

u

k
n

)

n
≥
1

(u_{kn})_{n\geq 1}

is uniformly distributed (mod 1) for every

k
k

in

K

\mathcal {K}

. We show that in fact

(

u

n

)

n
≥
1

(u_{n})_{n\geq 1}

is uniformly distributed (mod 1) whenever the subsequence

(

u

p
n

)

n
≥
1

(u_{pn})_{n\geq 1}

is uniformly distributed (mod 1) for every

p
∈

P

p\in \mathcal {P}

.
Homogenization of the inviscid incompressible fluid flow through a 2D porous medium
Authors: Mikelić Andro , Paoli Laetitia
Published: November 2002

We consider the non-stationary incompressible Euler equations in a 2D porous medium. We suppose a periodic porous medium, with the period proportional to the characteristic pore size

ε
\varepsilon

and with connected fluid part. The flow is subject to an external force, corresponding to an inflow. We start from an initial irrotational velocity and prove that the effective filtration velocity satisfies a transient filtration law. It has similarities with Darcy’s law, but it now connects the time derivative of the filtration velocity with the pressure gradient. The viscosity does not appear in the filtration law any more and the permeability tensor is determined through auxiliary problems of decomposition type. Using the limit problem, we construct the correction for the fluid velocity and prove that

C
1

(
[
0
,
T
]
;

L
2

(
Ω

)
2

)

C^1 ( [0,T]; L^2(\Omega )^2 )

-norm of the error is of order

ε
\varepsilon

. Similarly, we estimate the difference between the fluid pressure and its correction in

C
(
[
0
,
T
]
;

L
1

(
Ω
)
)

C ( [0,T]; L^1(\Omega ) )

as

C
ε

C \varepsilon

.
A sharp exponential inequality for Lorentz-Sobolev spaces on bounded domains
Authors: Hudson Steve , Leckband Mark
Published: November 2002

This paper generalizes an inequality of Moser from the case that

∇
u

\nabla u

is in the Lebesgue space

L
n

L^n

to certain subspaces, namely the Lorentz spaces

L

n
,
q

L^{n,q}

, where

1
>
q
≤
n

1>q\leq n

. The conclusion is that

exp
⁡
(
α

u
p

)

\exp (\alpha u^p)

is integrable, where

1

/

p
+
1

/

q
=
1

1/p+1/q=1

. This is a higher degree of integrability than in the Moser inequality when

q
>
n

q>n

. A formula for

α
\alpha

is given and it is also shown that no larger value of

α
\alpha

works.
On the semisimplicity of polyhedral isometries
Authors: Bridson Martin
Published: November 2002

If a polyhedral complex

K
K

has only finitely many isometry types of cells, then all of its cellular isometries are semisimple. If

K
K

is 1-connected and non-positively curved, then any solvable group that acts freely by cellular isometries on

K
K

is finitely generated and contains an abelian subgroup of finite index.
The Bernstein center in terms of invariant locally integrable functions
Authors: Moy Allen , Tadić Marko
Published: November 2002

We give a description of the Bernstein center of a reductive

p
p

-adic group

G
G

in terms of invariant locally integrable functions and compute a basis of these functions for the group

S
L
(
2
)

SL(2)

.
A nonlinear inverse simulation technique applied to coaxial rotor helicopter maneuvers
Authors: Su Yuan , Cao Yihua
Published: November 2002

As compared with the maneuvering flight studies for single main rotor helicopters, the corresponding studies for coaxial rotor helicopters are relatively poor. In this paper, the maneuvering flight governing equations for coaxial rotor helicopters is established. By introducing induced velocity interference factor analysis, the coaxial rotor aerodynamic interference can be taken into account. With the combination of coaxial rotor helicopter control features and nonlinear inverse simulation technique, the governing equations for maneuvering flight can be solved so as to determine helicopter control input, control force and moment, and helicopter body attitudes which are needed for performing a specified maneuver. Good results of the sample calculations of level turn and lateral jink maneuvers are obtained and simply analyzed.
A proposal of handling qualities shaping for general aviation aircraft
Authors: Tomczyk Andrzej
Published: November 2002

A proposal of the perspective solution of the general aviation aircraft control system is presented. The objective of the proposed concept for the control system is to assist pilots with limited aviation training by: automatic stabilization of the aircraft's attitude, altitude, airspeed, and heading and decoupling of the flight controls. The structure and main functions of the control system is presented, and method of control laws synthesis is proposed. Flight control system is based on the model‐following design technique. Two kinds of flight control systems are taken into consideration. The first solution is based on the optimal full‐state feedback controller, the second one is the simplified controller, using the easy observed states for feedback loop only. The project calculation of the flight control system for PZL‐110 “Koliber” aircraft, computer simulations and preliminary flight testing results will be presented.
An institutional perspective of non‐financial management accounting measures: a review of the financial services industry
Authors: Hussain Mostaque , Gunasekaran A.
Published: November 2002

The inadequacies of conventional management accounting (MA) systems increase the need of up‐to‐date MA information. However, critical non‐financial success factors are emerging in highly competitive technologically advanced business organisations, especially in the service sector with its increasing contribution to advanced economies and employment markets. As a result, the importance of the role of MA in measuring emerging non‐financial performance (NFP) is increasing in services, but comparatively little is known about non‐financial MA measures in services, and almost nothing in banks/financial institutions (BFI). This study attempts to review/investigate the practice of MA in NFP measurement of BFIs within the context of “new institutional sociology” theory and, consequently, to modify theory for further research that fits the dynamic nature of NFP in the financial services industry.
Politicians as utility maximizing agents
Authors: Mixon Franklin G. , Treviño Len J.
Published: November 2002

Public choice theory describes politicians as expected utility maximizing agents who are primarily concerned with their own election prospects. In a fashion similar to Anderson and Tollison, who showed that US President Abraham Lincoln manipulated the military vote in the US Presidential election of 1864, this note presents historical accounts of Winston Churchill’s efforts (desire) to suppress the overall military vote in the British National Election of 1945. The anecdotal evidence and election simulations presented suggest that Churchill’s expected utility maximization suppression strategy was consistent with public choice tenets. As such, the public choice interpretation of British political history presented here adds further to political‐economic models of legislator/executive behavior.
Leadership development in a South African health service
Authors: Dovey Ken
Published: November 2002

The paper reports the outcomes of one module of a collaborative learning project aimed at the development of leadership capacity in district health management teams in the East Cape province of South Africa. A work‐based learning methodology was selected for the module with the intention of developing strategic and procedural knowledge bases within these teams as a way of addressing the complex problems of policy implementation in South African state organisations. The paper demonstrates the effectiveness of collaborative work‐based projects in developing team members’ capacity to solve difficult workplace problems and to implement strategy in a challenging operational environment. It endorses the role of leadership coaching in the development of, and ability to leverage, important strategic knowledge resources that reside within and between team members. The paper concludes with an example that demonstrates the developing ability of team members to initiate successful collaboration around the resolution of complex service delivery problems.
Learning from experience: five challenges for retailers
Authors: Knee Christopher
Published: November 2002

Starting from the experience of department stores, this paper examines five challenges for retailing in the future. These are retail branding, people, growth, customer‐centredness, and performance and measurement. Each challenge is briefly developed from an unusual perspective, mixing management theories and cases. These challenges constitute strategic choices for the future for retailers and each have specific operational consequences.
The environment and its impact on the supply chain
Authors: Christensen Lawrence
Published: November 2002

Looks at how Safeway plc is helping the environment through its supply chain. Does this by using recyclable packing on its products, examining route and method of transport to market. Concludes that by recognizing environmental challenges organizations can benefit not only themselves, but all of us.
Ultrastructure and properties of Paecilomyces lilacinus spores
Authors: Holland R J , Gunasekera T S , Williams K L , Nevalainen K M.H
Published: November 2002

Strains of the filamentous soil fungus Paecilomyces lilacinus are currently being developed for use as biological control agents against root-knot, cyst, and other plant-parasitic nematodes. The inoculum applied in the field consists mainly of spores. This study was undertaken to examine the size, ultrastructure, and rodlet layers of P. lilacinus spores and the effect of the culture method on structural and functional spore properties. A rodlet layer was identified on aerial spores only. Other differences noted between aerial spores and those produced in submerged culture included the size and appearance of spores and thickness of spore coat layers when examined with transmission electron microscopy. The two spore types differed in UV tolerance, with aerial spores being less sensitive to environmentally relevant UV radiation. Also, viability after drying and storage was better with the aerial spores. Both spore types exhibited similar nematophagous ability.Key words: Paecilomyces lilacinus, fungal spores, rodlet layer, spore ultrastructure, UV sensitivity, biological control.
Effect of a combination therapy between IL-12 and soluble IL-4 receptor (sIL-4R) onCandida albicansand herpes simplex virus type 1 infections in thermally injured mice
Authors: Kobayashi Makiko , Takahashi Hitoshi , Herndon David N , Pollard Richard B , Suzuki Fujio
Published: November 2002

The effectiveness of a combination using IL-12 and soluble IL-4 receptor (sIL-4R) to treat severe infections of herpes simplex virus type 1 (HSV-1) and Candida albicans in thermally injured mice was investigated. Although sIL-4R decreased burn-associated type 2 T-cell responses, the effect of sIL-4R was minimal on the morbidity and mortality of thermally injured mice exposed to 250 times LD50of HSV-1 or 10 times LD50of C. albicans. Compared with 100% mortality in control mice, mortality for HSV-1 and C. albicans was 40 and 20%, respectively, in thermally injured mice that received IL-12 and sIL-4R in combination. After stimulation with anti-CD3 monoclonal antibody, splenic T cells from thermally injured mice exposed to large amounts of HSV-1 or C. albicans did not produce gamma interferon (IFN-γ) into their culture fluids. However, IFN-γ was produced by splenic T cells from thermally injured and infected mice treated with IL-12 and sIL-4R in combination. These results suggest that therapeutic treatment with a combination of IL-12 and sIL-4R may be effective by inducing type 1 T-cell responses in thermally injured mice exposed to large amounts of HSV-1 or C. albicans.Key words: burn, IL-12, soluble IL-4 receptor, herpesvirus, Candida albicans.
Effective dose of a microbial inoculant is one to four cells in the rhizosphere
Authors: Normander Bo , Hendriksen Niels Bohse
Published: November 2002

A single-cell approach for studying the growth potential and the establishment of bacteria in the barley phytosphere is presented, using Pseudomonas fluorescens strain with the capability for biological control. The incidence of growth of one to four bacterial cells dispersed to the young rhizosphere approximated to 100%, and specific growth rate averaged 0.05. Net growth occurred for cells added to the rhizosphere at densities between 1 and 100 000 cells, while at higher densities population sizes declined, but always approached 105106cells per rhizosphere. No net growth was observed in bulk soil, and cells died in the phyllosphere. Our results showed that bacterial establishment was more related to the availability of microhabitats supporting growth, than related to the number of bacteria released. Key words: risk assessment, bacterial fate, single-cell, Pseudomonas fluorescens, gfp.
TheglcBlocus ofRhizobium leguminosarumVF39 encodes an arabinose-inducible malate synthase
Authors: García-de los Santos Alejandro , Morales Alejandro , Baldomá Laura , Clark Scott R.D , Brom Susana , Yost Christopher K , Hernández-Lucas Ismael , Aguilar Juan , Hynes Michael F
Published: November 2002

In the course of a study conducted to isolate genes upregulated by plant cell wall sugars, we identified an arabinose-inducible locus from a transcriptional fusion library of Rhizobium leguminosarum VF39, carrying random insertions of the lacZ transposon Tn5B22. Sequence analysis of the locus disrupted by the transposon revealed a high similarity to uncharacterized malate synthase G genes from Sinorhizobium meliloti, Agrobacterium tumefaciens, and Mesorhizobium loti. This enzyme catalyzes the condensation of glyoxylate and acetyl-CoA to yield malate and CoA and is thought to be a component of the glyoxylate cycle, which allows microorganisms to grow on two carbon compounds. Enzyme assays showed that a functional malate synthase is encoded in the glcB gene of R. leguminosarum and that its expression is induced by arabinose, glycolate, and glyoxylate. An Escherichia coli aceB glcB mutant, complemented with the R. leguminosarum PCR-amplified gene, recovered malate synthase activity. A very similar genome organization of the loci containing malate synthase and flanking genes was observed in R. leguminosarum, S. meliloti, and A. tumefaciens. Pea plants inoculated with the glcB mutant or the wild-type strain showed no significant differences in nitrogen fixation. This is the first report regarding the characterization of a mutant in one of the glyoxylate cycle enzymes in the rhizobia.Key words: Rhizobium, malate synthase, glyoxylate cycle, arabinose metabolism.
Biochemical evidence against protein-mediated uptake of myristic acid in the bioluminescent marine bacteriumVibrio harveyi
Authors: Byers David M , Shen Zhiwei
Published: November 2002

The bioluminescent marine bacterium, Vibrio harveyi, can utilize exogenous myristic acid (14:0) for β-oxidation, phospholipid and lipid A synthesis, and as an source of myristyl aldehyde for light emission in the V. harveyi dark mutant M17. A variety of genetic and biochemical strategies were employed in an attempt to isolate V. harveyi mutants defective in myristate uptake and to characterize proteins involved in this process. Although [3H]myristate uptake in a tritium suicide experiment decreased the survival of nitrosoguanidine-treated M17 cells by a factor of 105, none of the surviving cells characterized were defective in either incorporation of exogenous myristate into phospholipid or stimulation of light emission. These parameters were also unaffected when intact M17 cells were treated with proteases. Moreover, M17 double mutants selected on the basis of diminished luminescence response to myristate all incorporated [3H]myristate into lipids normally. Finally, no resistant colonies were obtained using the bacteriocidal fatty acid analogue, 11-bromoundecanoate, and experiments with decanoate (10:0) indicated that the V. harveyi cell envelope is very sensitive to physical disruption by fatty acids. Taken together, these results support an unfacilitated uptake of myristic acid in V. harveyi, in contrast with the regulated vectorial transport and activation of long chain fatty acids in Escherichia coli.Key words: Vibrio harveyi, fatty acid transport, bioluminescence, lipid metabolism, tritium suicide.
MAGNETICALLY INDUCED "DRY" WATER LIKE STRUCTURE OF ELECTRON GAS IN DENSE STELLAR MATTER IN THE PRESENCE OF AN ULTRA STRONG MAGNETIC FIELD
Authors: GHOSH SUTAPA , CHAKRABARTY SOMENATH
Published: November 2002

It is shown that electron gas in dense stellar matter exhibit super-fluid (frictionless) like property if the magnetic field strength is high enough to populate only the zeroth Landau levels, i.e. it is possible that at the core of a magnetar, the proton matter behaves like a superconductor, neutron matter behaves like a super-fluid and electron gas shows super-fluidity without superconductivity. Therefore, the core region as a whole of a magnetar may behave like a frictionless matter which is quite surprising.
EXTENDED SCALAR GRAVITY TO (2 + 1) DIMENSIONS: CHARGED AND ROTATING SOLUTIONS
Authors: SOBREIRA A. A. RODRIGUES , BEZERRA V. B.
Published: November 2002

We consider the scalar gravity theory in (2 + 1) dimensions and find an electrically charged and a rotating black hole solutions. The first solution was obtained by combining the scalar gravity and Maxwell equations and the second one by applying the method of complex coordinate transformation to the nonrotating counterpart solution.
MAPPING OF NON-CENTRAL POTENTIALS UNDER POINT CANONICAL TRANSFORMATIONS
Authors: KOCAK M. , ZORBA I. , GÖNÜL B.
Published: November 2002

Motivated by the observation that all known exactly solvable shape invariant central potentials are inter-related via point canonical transformations, we develop an algebraic framework to show that a similar mapping procedure also exists between a class of non-central potentials. As an illustrative example, we discuss the inter-relation between the generalized Coulomb and oscillator systems.
GENERALIZED WEYL SYSTEMS AND κ-MINKOWSKI SPACE
Authors: AGOSTINI ALESSANDRA , LIZZI FEDELE , ZAMPINI ALESSANDRO
Published: November 2002

We introduce the notion of generalized Weyl system, and use it to define *-products which generalize the commutation relations of Lie algebras. In particular we study in a comparative way various *-products which generalize the κ-Minkowski commutation relation.
EXPLORING FEATURES AND CLASSIFIERS TO CLASSIFY GENE EXPRESSION PROFILES OF ACUTE LEUKEMIA
Authors: CHO SUNG-BAE
Published: November 2002

Bioinformatics has recently drawn a lot of attention to efficiently analyze biological genomic information with information technology, especially pattern recognition. In this paper, we attempt to explore extensive features and classifiers through a comparative study of the most promising feature selection methods and machine learning classifiers. The gene information from a patient's marrow expressed by DNA microarray, which is either the acute myeloid leukemia or acute lymphoblastic leukemia, is used to predict the cancer class. Pearson's and Spearman's correlation coefficients, Euclidean distance, cosine coefficient, information gain, mutual information and signal to noise ratio have been used for feature selection. Backpropagation neural network, self-organizing map, structure adaptive self-organizing map, support vector machine, inductive decision tree and k-nearest neighbor have been used for classification. Experimental results indicate that backpropagation neural network with Pearson's correlation coefficients produces the best result, 97.1% of recognition rate on the test data.
STEREO MATCHING ALGORITHMS BASED ON FUZZY APPROACH
Authors: KUMAR S. SRINIVAS , CHATTERJI B. N.
Published: November 2002

Stereo matching is the central problem of stereovision paradigm. Area-based techniques provide the dense disparity maps and hence they are preferred for stereo correspondence. Normalized cross correlation (NCC), sum of squared differences (SSD) and sum of absolute differences (SAD) are the linear correlation measures generally used in the area-based techniques for stereo matching. In this paper, similarity measure for stereo matching based on fuzzy relations is used to establish the correspondence in the presence of intensity variations in stereo images. The strength of relationship of fuzzified data of two windows in the left image and the right image of stereo image pair is determined by considering the appropriate fuzzy aggregation operators. However, these measures fail to establish correspondence of the pixels in the stereo images in the presence of occluded pixels in the corresponding windows. Another stereo matching algorithm based on fuzzy relations of fuzzy data is used for stereo matching in such regions of images. This algorithm is based on weighted normalized cross correlation (WNCC) of the intensity data in the left and the right windows of stereo image pair. The properties of the similarity measures used in these algorithms are also discussed. Experiments with various real stereo images prove the superiority of these algorithms over normalized cross correlation (NCC) under nonideal conditions.
ON THE DEFINABILITY OF THE DOUBLE JUMP IN THE COMPUTABLY ENUMERABLE SETS
Authors: CHOLAK PETER A. , HARRINGTON LEO A.
Published: November 2002

We show that the double jump is definable in the computably enumerable sets. Our main result is as follows: let [Formula: see text] is the Turing degree of a [Formula: see text] set J ≥T0″}. Let [Formula: see text] such that [Formula: see text] is upward closed in [Formula: see text]. Then there is an ℒ(A) property [Formula: see text] such that [Formula: see text] if and only if there is an A where A ≡T F and [Formula: see text]. A corollary of this is that, for all n ≥ 2, the high n ([Formula: see text]) computably enumerable degrees are invariant in the computably enumerable sets. Our work resolves Martin's Invariance Conjecture.
The Spa: Emotional Economy and Social Classes in Nineteenth-Century Pyrmont
Authors: Lempa Heikki
Published: November 2002

In1835, Ferdinand Gustav Kühne, a Saxon writer and teacher, estimated that the Germanic realm was inundated with spas and that nowhere else were there as many as in Central Europe. In France there were “only ten springs, in Italy eight, Hungary had twelve, Sweden three, Spain two, England two, in Denmark and in vast Russia there was only one mineral spring of note in each, whereas in German-speaking countries, that is, including Bohemia and Switzerland, 149 facilities claimed to possess healing springs.” Although Kühne's estimate of foreign spas was too low—according to recent studies, the number of spas in England and France was significantly higher—contemporary accounts and recent local studies support his finding that Germans had the most bathing facilities in Europe. Fred Kaspar has isolated ninety-nine spas and mineral springs in Westphalia alone. Beginning in the last third of the eighteenth century, the number of spas and spa goers in particular increased rapidly in the Germanic realm. Only 200 guests came to the Kissingen spa in the summer of 1800, whereas fifty years later there were close to 4,000 and by the turn of the century 15,000 guests proper and more than 20,000 day visitors. Pyrmont, one of the most popular spas in the eighteenth century, started with 1,424 guests proper (not including peasants who were not considered guests proper) reaching 2,800 guests by the middle of the century, and around 19,000 by 1900.
The German Empire, 1871–1914: Reflections on the Direction of Recent Research
Authors: Berghahn Volker R.
Published: November 2002

Thisrather brief essay represents an attempt to raise a problem relating to the direction that much of recent research on Imperial Germany has taken. The deliberations that follow emerge from a renewed and quite extensive reading of the secondary literature on the history of the German Empire that I undertook in connection with my contribution to the 1806–1918 volume of the 10th edition ofGebhardt's Handbuch der Deutschen Geschichte, edited by Jürgen Kocka. Although my research interests had moved into other fields of German and European history following my work on the sociopolitical history of the Wilhelmian period, I confess that, like so many fellow historians, I continue to be fascinated by those decades before 1914. So, even if I have not been back to the archives, I have been trying to follow the no doubt rich “post-Bielefeld” output of what are by now at least two consecutive generations of younger scholars in this field.
Effect of follow‐up time on risk estimates: A longitudinal examination of the relative risks of leukemia and multiple myeloma in a rubber hydrochloride cohort
Authors: Silver S.R. , Rinsky R.A. , Cooper S.P. , Hornung R.W. , Lai D.
Published: November 2002

Background

Choice of follow‐up time for an occupational cohort can influence risk estimates. We examined the effects of follow‐up time on relative risk estimates for leukemia and multiple myeloma in a cohort of 1,845 rubber hydrochloride workers.

Materials and Methods

We generated standardized mortality ratios (SMRs) for yearly follow‐ups, beginning each study in 1940 and increasing study end dates from 1950 through 1996. We used Cox proportional hazards modeling to explore the effects of follow‐up time on the exposure–response relationship.

Results

The SMR for leukemia rose to 13.55 in 1961 and fell nearly monotonically to 2.47 by 1996. Cox modeling suggested interaction between cumulative exposure and time since exposure. A longer time to peak risk was seen for multiple myeloma.

Conclusions

Because summary risk estimates change with follow‐up time, exposure limits set using these estimates may not adequately protect workers. Consideration of appropriate follow‐up time and use of more complex temporal models are critical to the risk assessment process. Am. J. Ind. Med. 42:481–489, 2002. Published 2002 Wiley‐Liss, Inc.
Numerical stability and error analysis for the incompressible Navier–Stokes equations
Authors: Prudhomme S. , Oden J. T.
Published: November 2002

This paper describes a strategy to control errors in finite element approximations of the time‐dependent incompressible Navier–Stokes equations. The approach involves estimating the errors due to the discretization in space, using information from the residuals in the momentum and continuity equations. Following a numerical stability analysis of channel flows past a cylinder, it is concluded that the errors due to the residual in the continuity equation should be carefully controlled since it appears to be the source of unphysical perturbations artificially created by the spatial discretization. The performance of the adaptive strategy is then tested for lid‐driven oblique cavity flows. Copyright © 2002 John Wiley & Sons, Ltd.
Method of fundamental solutions: singular value decomposition analysis
Authors: Ramachandran P. A.
Published: November 2002

The method of fundamental solutions (also known as the singularity or the source method) is a useful technique for solving linear partial differential equations such as the Laplace or the Helmholtz equation. The procedure involves only boundary collocation or boundary fitting and hence is a very fast procedure for the solution of these classes of problems. The resulting coefficient matrix, is however ill‐conditioned and hence the solution accuracy is sensitive to the location of the source points. In this paper, an alternative solution procedure based on the singular value decomposition of the coefficient matrix is suggested and it is shown that the numerical results are extremely accurate (often within machine precision) and relatively independent of the location of the source points. Copyright © 2002 John Wiley & Sons, Ltd.
Production of essential oil constituents by cultured cells of Carum copticum L.
Authors: Lockwood G. B. , Asghari G. , Hakimi B.
Published: November 2002

Callus cultures of Carum copticum were established from cotyledons and healthy suspensions grown using Murashige and Skoog medium. The dichloromethane extract of cell suspension culture of Carum copticum was analysed by GC and GC–MS; 41 components were identified, of which the major constituents were found to be elemol (11.5%), α‐cadinol (10.6%), δ‐cadinene (7.8%), caryophyllene (6.2%), muurolol (4.9%), β‐eudesmol (3.1%), β‐elemene (3.9%), α‐muurolene (2.6%), limonene (2.4%) and α‐humulene (2.0%). Copyright © 2002 John Wiley & Sons, Ltd.
Chemical and biological studies of Ocotea comoriensis bark essential oil
Authors: Menut C. , Bessière J. M. , Said Hassani M. , Buchbauer G. , Schopper B.
Published: November 2002

The essential oil of Ocotea comoriensis Kostermans (Lauraceae) was obtained from bark by hydrodistillation of plant material collected in the Comoros Islands. Analysis by GC and GC–MS indicates a terpenic chemical composition, with camphene, α‐pinene and bornyl acetate as the major components. The volatile extract did not reveal important antioxidant, larvicide or antimalarial properties. Copyright © 2002 John Wiley & Sons, Ltd.
Fragrances: are they safe?
Authors: Cadby Peter A. , Troy William R. , Middleton John D. , Vey Matthias G. H.
Published: November 2002

In recent years it has become fashionable to criticize the use of fragrances in our society, suggesting that this use is associated with a variety of negative effects. We review the key areas of criticism, which have suggested adverse safety and environmental effects, with an emphasis on the science, rather than speculation, regarding these issues. In conclusion, an adequate review and testing mechanism exists to assure the safety of fragrance materials, and their combination in mixtures, for the consumers of fragranced products. Copyright © 2002 John Wiley & Sons, Ltd.
An efficient synthesis and crystal structure of novel 1‐oxo‐2‐propyl‐4‐(substituted)phenylimino‐1,2,3,4,5,6,7,8‐octahydro[1,4,3]thiazaphosphorino[4,3‐a][1,3,2]benzodiazaphosphorine 3‐oxides
Authors: Huang Junmin , Chen Hui , Chen Ruyu
Published: November 2002

A series of 1‐oxo‐2‐propyl‐4‐(substituted)phenylimino‐1,2,3,4,5,6,7,8‐octahydro‐[1,4,3]thiazaphosphorino[4,3‐a][1,3,2]benzodiazaphosphorine 3‐oxides (5a–g) has been synthesized in excellent yields via the reaction of 1‐(2‐bromoethyl)‐2,3‐dihydro‐3‐propyl‐1,3,2‐benzodiazaphosphorin‐4(1H)‐one 2‐oxide with (substituted) phenyl isothiocyanates, which contain the proximate imino and phosphoryl groups in the fused heterocycle. The structures of all of the new compounds were confirmed by spectroscopic methods and microanalyses. The results from X‐ray crystallography analysis of 5a showed that the proximate imino and phosphoryl groups are not coplanar due to their being jointly located in the fused heterocycle, thus having ring tension, and this then destroys the conjugation between the CN and the PO moieties. As a result, the length of the PC bond, measured as 1.8285(18) Å, is just the same as that of a PC bond not involved in conjugation (1.80–1.85 Å). Also, the C(1), C(2), S(1), C(3), P(1), and N(2) atoms of the [1,4,3]thiazaphosphorino moiety exist preferably in the boat conformation. The coplanar C(1), N(2), C(3), and S(1) atoms, within an average deviation of 0.0564 Å, form the ground floor of the boat conformation, whereas, the P(1) and C(2) atoms are on the same side of the coplanar structure with the distance of 0.7729 Å and 0.7621 Å, respectively. On the other hand, around the CN double bond, the P(1)C(3) bond and the N(1)C(11) bond are in a trans relationship because of the repulsive action of the n‐propyl group in the 2‐position of the title compound. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:599–610, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10041
Interactions of a new 2‐styrylchromone with mitochondrial oxidative phosphorylation
Authors: Peixoto Francisco , Barros Ana I. R. N. A. , Silva Artur M. S.
Published: November 2002

Many chromones, especially those having 2‐substituents, manifest a remarkable variety of biological activities, such as the important cytotoxicity against human leukaemia cells, antiallergic, anticancer activities; unfortunately chromones normally disturb mitochondrial bioenergetics. A new 2‐styrylchromone has been synthesized by the Baker–Venkataraman method and a classical approach has been used to assess the effects of 2‐styrylchromone (3′‐allyl‐4′,5,7‐trimethoxy‐2‐styrylchromone) on rat liver mitochondrial bioenergetic. Mitochondrial respiratory rate and transmembrane potential were measured polarographically using a Clark oxygen electrode and with a selective electrode, respectively. All the disturbance induced by 2‐styrylchromone on the enzymatic activities (succinate dehydrogenase, succinate cytochrome c reductase, and cytochrome c oxidase) and in the mitochondrial osmotic volume were determined spectrophotometrically. State 4, state 3, and uncoupled (presence of carbonylcyanide p‐trifluoromethoxyphenylhydrazone) respiration rates were decreased by 2‐styrylchromone in a concentration‐dependent manner. Depression of respiratory activity promoted by 2‐styrylchromone is essentially mediated through partial inhibition of succinate cytochrome c reductase. Phosphorylation capacity was strongly depressed as a result of an inhibition on the enzymatic complex (F0F1‐ATPase) and also because of a deleterious effect on the integrity of the mitochondrial membrane, which uncoupled the respiration‐generated proton gradient with the proton‐driven phosphorylation. The structural integrity of the outside membrane is severely affected since cytochrome c can be released. 2‐Styrylchromone uncouples oxidative phosphorylation by an inhibitory action on the redox chain and ATP synthase activity. Additionally, it can release cytochrome c. Cell death can probably result due to the induction of procaspase‐9 and other procaspases and by a strong decrease of the available ATP. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:220–226, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10042
Improved antisense oligonucleotide induced exon skipping in the mdx mouse model of muscular dystrophy
Authors: Mann Christopher J. , Honeyman Kaite , McClorey Graham , Fletcher Sue , Wilton Stephen D.
Published: November 2002

Background

Duchenne muscular dystrophy (DMD) is a fatal genetic disorder caused by dystrophin gene mutations that preclude synthesis of a functional protein. One potential treatment of the disorder has utilised antisense oligoribonucleotides (AOs) to induce removal of disease‐associated exons during pre‐mRNA processing. Induced in‐frame mRNA transcripts encode a shorter but functional dystrophin. We have investigated and improved the design of AOs capable of removing exon 23, and thus the disease‐causing nonsense mutation, from mRNA in the mdx mouse model of DMD.

Methods

H−2Kb‐tsA58 mdx cultures were transfected with complexes of Lipofectin and AOs. Exon skipping was detected by RT‐PCR and subsequent protein production was demonstrated by Western blotting. AOs were delivered at a range of doses in order to compare relative efficiencies.

Results

We describe effective and reproducible exon 23 skipping with several AOs, including one as small as 17 nucleotides. Furthermore, the location of a sensitive exon 23 target site has been refined, whilst minimum effective doses have been estimated in vitro. These doses are significantly lower than previously reported and were associated with the synthesis of dystrophin protein in vitro.

Conclusions

These results demonstrate the increasing feasibility of an AO‐based therapy for treatment of DMD. By refining AO design we have been able to reduce the size and the effective dose of the AOs and have dramatically improved the efficiency of the technique. Copyright © 2002 John Wiley & Sons, Ltd.
Listeria monocytogenes mediated CFTR transgene transfer to mammalian cells
Authors: Krusch Stefan , Domann Eugen , Frings Monika , Zelmer Andrea , Diener Martin , Chakraborty Trinad , Weiss Siegfried
Published: November 2002

Background

Several approaches for gene therapy of cystic fibrosis using viral and non‐viral vectors are currently being undertaken. Nevertheless, the present data suggest that vectors currently being used will either have to be further modified or, alternatively, novel vector systems need to be developed. Recently, bacteria have been proven as suitable vehicles for DNA transfer to a wide variety of eukaryotic cells. In this study, we assessed the ability of the facultative intracellular pathogen Listeria monocytogenes to deliver a cDNA encoding the human cystic fibrosis transmembrane conductance regulator (CFTR) to CHO‐K1 cells, since these cells have been extensively used for heterologous CFTR expression.

Methods

An established in vitro gene transfer system based on antibiotic‐mediated lysis of intracellular L. monocytogenes was exploited to transfer eukaryotic expression plasmids. Transient as well as stable CFTR transgene expression was analyzed by microscopical and biochemical methods; functionality was tested by whole‐cell patch‐clamp recordings.

Results

L. monocytogenes mediated gene transfer to CHO‐K1 cells was facilitated by an improved transfection protocol. In addition, the use of the isogenic mutant L. monocytogenes hlyW491A, engineered to produce a hemolysin variant with low toxigenic activity, greatly enhanced the efficiency of gene transfer. This strain allowed the transfer of functional CFTR to CHO‐K1 cells.

Conclusions

This is the first demonstration of L. monoyctogenes mediated CFTR transgene transfer. The successful in vitro transfer suggests that L. monocytogenes might be a potential vector for cystic fibrosis gene therapy or alternative applications and deserves further investigation in vitro as well as in vivo. Copyright © 2002 John Wiley & Sons, Ltd.
A NOTE ON TWO RELIABILITY LOWER BOUNDS FOR MULTISTATE SYSTEMS
Authors: Meng Fan C.
Published: November 2002

Maymin proved that for binary systems, the path-cut lower bound
is sharper than the minimax lower bound for highly reliable
components, which was originally conjectured by Barlow and
Proschan. In this note, an example is constructed to illustrate
that this, in general, is not the case for multistate systems.
However, an affirmative result is obtained under mild conditions
we imposed. Examples are given to illustrate the applications
of our results.
WELFARE IMPLICATIONS OF FACTOR TAXATION WITH RISING WAGE INEQUALITY
Authors: Blankenau William F. , Ingram Beth F.
Published: November 2002

In recent decades, the structure of wages in the U.S. economy has shifted to favor workers with college degrees over those without college degrees. Concurrently, there has been an increase in the share of the workforce that is college educated. We build an overlapping generations model in which skill-biased technological change drives both rising wage inequality and a rising percentage of skilled (educated) workers in the labor force. We explore the implications for agent welfare and for the distribution of income of different factor taxation choices. We find that higher tax rates on capital and lower tax rates on unskilled labor can yield steady-state welfare gains across a heterogeneous population, and that these gains increase as the economy experiences technological change that favors skilled labor. Moreover, these shifts in taxation can lower net wage inequality. Steady-state welfare gains, however, come at the expense of agents alive upon implementation.
SURVEY OF LINEAR QUADRATIC ROBUST CONTROL
Authors: Bernhard Pierre
Published: November 2002

We review several control problems, all related to robust control in some way, that lead to a minimax linear quadratic problem. We stress the fact that although an augmented performance index appears, containing an L2 norm of a disturbance signal, only the nonaugmented quadratic performance index is of interest per se in each case.
ROBUST PERMANENT INCOME AND PRICING WITH FILTERING
Authors: Hansen Lars Peter , Sargent Thomas J. , Wang Neng E.
Published: November 2002

A planner and agent in a permanent-income economy cannot observe part of the state, regard their model as an approximation, and value decision rules that are robust across a set of models. They use robust decision theory to choose allocations. Equilibrium prices reflect the preference for robustness and so embody a “market price of Knightian uncertainty.” We compute market prices of risk and compare them with a model that assumes that the state is fully observed. We use detection error probabilities to constrain a single parameter that governs the taste for robustness.
KNIFE-EDGE CONDITIONS AND THE MACRODYNAMICS OF SMALL OPEN ECONOMIES
Authors: Turnovsky Stephen J.
Published: November 2002

Macrodynamic models of small open economies are inevitably characterized by “knife-edge conditions,” meaning that certain parameters are constrained for a viable equilibrium to exist. This paper examines the macrodynamic structure of such an economy and considers the role played by various standard knife-edge conditions. The dynamic model presented is sufficiently general so as to provide a unifying framework within which alternative models can be embedded. We identify three important models as special cases of this generic structure: (i) The traditional stationary Ramsey model, (ii) the endogenous growth model, and (iii) the nonscale growth model. We consider three margins along which knife-edge conditions are imposed. These include (i) preference parameters, (ii) production and employment characteristics, and (iii) openness of international financial markets. These restrictions are shown to play key roles in determining the equilibrium dynamics, and how the economy responds to various shocks. The existence of trade-offs between these knife-edge conditions is discussed.
A SPECTRAL-BASED CUSUM TEST OF EVOLUTIONARY CHANGE
Authors: Wild Phillip
Published: November 2002

We develop a test of evolutionary change that incorporates a null hypothesis of homogeneity, which encompasses time invariance in the variance and autocovariance structure of residuals from estimated econometric relationships. The test framework is based on examining whether shifts in spectral decomposition between two frames of data are significant. Rejection of the null hypothesis will point not only to weak nonstationarity but to shifts in the structure of the second-order moments of the limiting distribution of the random process. This would indicate that the second-order properties of any underlying attractor set has changed in a statistically significant way, pointing to the presence of evolutionary change. A demonstration of the test's applicability to a real-world macroeconomic problem is accomplished by applying the test to the Australian Building Society Deposits (ABSD) model.
Urban Settlement Transitions
Authors: Andersson Claes , Rasmussen Steen , White Roger
Published: November 2002

Urban growth dynamics attracts the efforts of scientists from many different disciplines with objectives ranging from theoretical understanding to the development of carefully tuned realistic models that can serve as planning and policy tools. Theoretical models are often abstract and of limited applied value while most applied models yield little theoretical understanding. Here we present a mathematically well-defined model based on a modified Markov random field with lattice-wide interactions that produces realistic growth patterns as well as behavior observed in a range of other models based on diffusion-limited aggregation, cellular automata, and similar models. We investigate the framework's ability to generate plausible patterns using minimal assumptions about the interaction parameters since the tuning and specific definition of these are outside of the scope of this paper. Typical universality classes of the simulated dynamics and the phase transitions between them are discussed in the context of real urban dynamics. Using suitability data derived from topography, we produce configurations quantitatively similar to real cities. Also, an intuitive class of interaction rules is found to produce fractal configurations, not unlike vascular systems, that resemble urban sprawl. The dynamics are driven by interactions, depicting human decisions, between all lattice points. This is realized in a computationally efficient way using a mean-field renormalization (area average) approach. The model provides a mathematically transparent framework to which any level of detail necessary for actual urban planning application can be added.
Russian Power Generation: Between a Rock and a Hard Place?
Authors: Hill Malcolm R
Published: November 2002

This paper discusses the recent and future operational performance of the Russian electricity-generation industry, which is central to government plans for industrial regeneration and environmental improvement. The paper commences with information on outputs from the industry, namely current and future production levels, and atmospheric emissions, followed by data on fuel and capacity inputs. Information is then presented to show that the meeting of future output targets may run counter to objectives for reduction of greenhouse gas emissions, in view of the slow replacement of ageing plant and the plans to switch fuel from natural gas back to coal. The paper then discusses the economic and commercial factors influencing the strategic choices available to the Russian power-generation industry and the barriers to the implementation of these alternatives. The conclusion is reached that substantial investment is required in Russian power stations, which may require significant increases in electricity prices with associated economic and social problems for industrial and domestic consumers. The pricing system could also be used to reduce demand to match the capacities of available equipment, but that decision may also give rise to associated economic and social problems.
Dynamics of Supply Chains: A Multilevel (Logistical–Informational–Financial) Network Perspective
Authors: Nagurney Anna , Ke Ke , Cruz Jose , Hancock Kitty , Southworth Frank
Published: November 2002

In this paper, we propose a multilevel network perspective for the conceptualization of the dynamics underlying supply chains in the presence of competition. The multilevel network consists of: the logistical network, the informational network, and the financial network. We describe the behavior of the network decisionmakers, which are spatially separated and which consist of the manufacturers and producing firms, the retailers, and the consumers located at the demand markets. We propose a projected dynamical system, along with stability analysis results, that captures the adjustments of the commodity shipments and the prices over space and time. A discrete-time adjustment process is described and implemented in order to illustrate in several numerical examples the evolution of the commodity shipments and prices to the equilibrium solution.