bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxicological Risk Assessment of Soil Contaminants
Authors: Kalberlah Fritz , Hassauer Martin , Frijus-Plessen Nicole , Schneider Klaus
Published: July 2002

International bodies such as the World Health Organization (WHO) and national governmental agencies like the U.S. Environmental Protection Agency (EPA) use the same basic concept to derive acceptable daily intake (ADI) and reference dose (RfD). This customary concept is used in toxicological risk assessment of soil contaminants in Germany. It is used in the following ways: with extension to new substances not yet assessed by, for example, WHO or EPA; with reevaluations for substances with new toxicologically relevant input data; with explicitly stated absorption rates used to calculate internal exposure; its results are presented differently and are better suited to multipathway situations of exposure such as in contaminated sites; and with extensions in assessment by assigning quality criteria to unit risk quantifications to carcinogenic substances. The respective derived doses are called TRD (tolerable resorbiente dosis—tolerable absorbed dose) values, that is, reference values equivalent to a no observed adverse effect level in sensitive human subpopulations. TRD values are proposed for approximately 85 soil contaminants and 20 warfare substances with high priority in Germany up to now. The article outlines some of the specific problems in deriving TRD values and gives examples for comparison with ADI (WHO) or RfD (EPA) values.
Concepts in the Netherlands of Risk Assessment of Soil Contamination
Authors: Theelen Rob M. C.
Published: July 2002

In 1994, a new Soil Protection Act was implemented in The Netherlands. It states that risk assessments are to be performed if the intervention value is exceeded. The intervention values reflect potential risks of contaminated soil or groundwater for humans or the ecosystem. The Act also describes in detail the methodology to be used. In the case that an intervention value is exceeded by a certain substance, the urgency of remediation has to be defined. This is to be done by a site-specific risk assessment, determining the current risks posed to humans and the ecosystem. In this article, the Dutch system is critically reviewed and compared to a German technique (in development). It is concluded that international harmonization is needed in the field of parameters and toxicological data that are used in the different models.
Association analysis of a PAX‐6 gene promoter‐associated polymorphic repeat with alcohol dependence
Authors: SAMOCHOWIEC JERZY , ROTTMANN MATTHIAS , OKLADNOVA OLGA , SYAGAILO YANA , STÖBER GERALD , SANDER THOMAS , MÜHLBAUER ECKHARD , SMOLKA MICHAEL , TRANITZ MICHAEL , WINTERER GEORG , ROMMELSPACHER HANS , SCHMIDT LUTZ G. , LESCH KLAUS‐PETER
Published: July 2002

The human paired box‐containing gene PAX‐6 participates in the development and plasticity of the brain including the limbic system, the neural system that plays a crucial role in reward processes. We have reported recently a polymorphic dinucleotide repeat sequence with the structure (AC)m(AG)n, which is located ∼ 1 kb upstream of the transcription initiation site associated with promoter B and confers allelic variation of PAX‐6 expression in the human brain. In the present association study we tested whether length variation of PAX‐6 gene‐linked polymorphic region (PAX‐6 LPR) influences susceptibility to alcohol dependence.The repeat length of the PAX‐6 LPR was assessed in 354 control subjects and 328 alcohol‐dependent patients, including four subgroups with a presumed substantial genetic predisposition: (a) with a history of withdrawal complications (n=100); (b) with a history of parental alcoholism (n=115); (c) with early onset (n=67) and (d) with dissocial personality disorders (n=54). Allelic distribution of the PAX‐6 LPR did not differ significantly between the controls and the entire group of alcohol‐dependent patients (χ2=0.015, df 1, p=0.904), or any of the subgroups of patients with severe alcoholism. Our results do not provide evidence that length variation of the PAX‐6 LPR contributes to the pathogenesis of alcohol dependence.
Book and Media Reviews
Authors: COOK CHRIS
Published: July 2002

Book reviewed in this article:

Book reviews in this column will primarily be of titles focusing completely, or in part, on biolog ical aspects of addiction. However, significant titles of general relevance to the addictions field will also be included, even if they are not “biological”, as will titles of general methodological and clinical relevance, even if they are not on “addictions”. Similar considerations will apply to other media (software, audio tapes and CDs, videos, etc). However, specific “addictions” software applications seem to be relatively uncommon and, as these items are rarely reviewed elsewhere, we will endeavour to include reviews of some of the older programmes that are still useful, as well as new titles that appear. I would appreciate suggestions of any items suitable for reviews, but especially software and other media of specific relevance to the addictions. Please contact: Professor Chris Cook, Kent Institute of Medicine and Health Sciences, University of Kent at Canterbur y, Kent CT2 7NR, UK. Email: c.c.h.cook@ukc.ac.uk

Drugs and Drug Abuse: a reference text, 3rd Edition B. BRANDS, B. SPROULE & J. MARSHMAN (Eds)

Illegal Leisure ‐ the normalization of adolescent recreational drug use H. PARKER, J. ALDRIDGE & F. MEASHAM

The Love Drug: marching to the beat of Ecstasy RICHARD S. COHEN

From Local Prevention to European Approach (English Section)

An Introduction to Therapeutic Communities DAVID KENNARD

Mechanisms of Disease: an introduction to clinical sciences S. TOMLINSON, A. M. HEAGERTY & A. P. WEETMAN (Eds)

I Wish I'd Made You Angry Earlier Essays on Science, Scientists, and Humanity MAX PERUTZ

Statistics for the Biosciences W. P. GARDINER

Software An Electronic Companion to Genetics PHILIP ANDERSON & BARRY GANETZKY
Oncogenic K-Ras and Basic Fibroblast Growth Factor Prevent FAS-Mediated Apoptosis in Fibroblasts through Activation of Mitogen-Activated Protein Kinase
Authors: Kazama Hirotaka , Yonehara Shin
Published: July 2002

By an expression cloning method using Fas-transgenic Balb3T3 cells, we tried to obtain inhibitory genes against Fas-mediated apoptosis and identified proto-oncogene c-K-ras. Transient expression of K-Ras mutants revealed that oncogenic mutant K-Ras (RasV12) strongly inhibited, whereas dominant-inhibitory mutant K-Ras (RasN17) enhanced, Fas-mediated apoptosis by inhibiting Fas-triggered activation of caspases without affecting an expression level of Fas. Among the target molecules of Ras, including Raf (mitogen-activated protein kinase kinase kinase [MAPKKK]), phosphatidylinositol 3 (PI-3) kinase, and Ral guanine nucleotide exchange factor (RalGDS), only the constitutively active form of Raf (Raf-CAAX) could inhibit Fas-mediated apoptosis. In addition, the constitutively active form of MAPKK (SDSE-MAPKK) suppressed Fas-mediated apoptosis, and MKP-1, a phosphatase specific for classical MAPK, canceled the protective activity of oncogenic K-Ras (K-RasV12), Raf-CAAX, and SDSE-MAPKK. Furthermore, physiological activation of Ras by basic fibroblast growth factor (bFGF) protected Fas-transgenic Balb3T3 cells from Fas-mediated apoptosis. bFGF protection was also dependent on the activation of the MAPK pathway through Ras. All the results indicate that the activation of MAPK through Ras inhibits Fas-mediated apoptosis in Balb3T3 cells, which may play a role in oncogenesis.
Protein Kinase C Activation Promotes Microtubule Advance in Neuronal Growth Cones by Increasing Average Microtubule Growth Lifetimes
Authors: Kabir Nurul , Schaefer Andrew W. , Nakhost Arash , Sossin Wayne S. , Forscher Paul
Published: July 2002

We describe a novel mechanism for protein kinase C regulation of axonal microtubule invasion of growth cones. Activation of PKC by phorbol esters resulted in a rapid, robust advance of distal microtubules (MTs) into the F-actin rich peripheral domain of growth cones, where they are normally excluded. In contrast, inhibition of PKC activity by bisindolylmaleimide and related compounds had no perceptible effect on growth cone motility, but completely blocked phorbol ester effects. Significantly, MT advance occurred despite continued retrograde F-actin flow—a process that normally inhibits MT advance. Polymer assembly was necessary for PKC-mediated MT advance since it was highly sensitive to a range of antagonists at concentrations that specifically interfere with microtubule dynamics. Biochemical evidence is presented that PKC activation promotes formation of a highly dynamic MT pool. Direct assessment of microtubule dynamics and translocation using the fluorescent speckle microscopy microtubule marking technique indicates PKC activation results in a nearly twofold increase in the typical lifetime of a MT growth episode, accompanied by a 1.7-fold increase and twofold decrease in rescue and catastrophe frequencies, respectively. No significant effects on instantaneous microtubule growth, shortening, or sliding rates (in either anterograde or retrograde directions) were observed. MTs also spent a greater percentage of time undergoing retrograde transport after PKC activation, despite overall MT advance. These results suggest that regulation of MT assembly by PKC may be an important factor in determining neurite outgrowth and regrowth rates and may play a role in other cellular processes dependent on directed MT advance.
Identification of a Committed T Cell Precursor Population in Adult Human Peripheral Blood
Authors: Bruno Ludovica , Res Pieter , Dessing Mark , Cella Marina , Spits Hergen
Published: July 2002

Here, we report data concerning the discovery in adult human peripheral blood of a precursor cell population able to differentiate into CD4+CD3+αβ+ mature T cells. These cells, which represent 0.1–0.5% of total peripheral blood mononuclear cells (PBMC), express substantial levels of CD4, but lack CD3 surface expression. At a molecular level, they express the pre-T cell receptor α (pTα) gene, CD3-γ, CD-δ and CD-ε, and RAG-1 recombination enzyme and have initiated rearrangements in the T cell receptor (TCR)-β locus (D–J). Moreover, low levels of CD3ε protein, but not of TCR-β chain, can be detected in their cytoplasm. Our results suggest that CD4+CD3− cells identified in peripheral blood are different from CD3−CD4+CD8− thymocytes and may contain precursors of an extrathymic T cell differentiation pathway.
Epitope-dependent Selection of Highly Restricted or Diverse T Cell Receptor Repertoires in Response to Persistent Infection by Epstein-Barr Virus
Authors: Campos-Lima Pedro-Otavio de , Levitsky Victor , Imreh Martha P. , Gavioli Riccardo , Masucci Maria G.
Published: July 2002

The T cell receptor (TCR) repertoires of cytotoxic responses to the immunodominant and subdominant HLA A11–restricted epitopes in the Epstein-Barr virus (EBV) nuclear antigen-4 were investigated in four healthy virus carriers. The response to the subdominant epitope (EBNA4 399-408, designated AVF) was highly restricted with conserved Vβ usage and identical length and amino acid motifs in the third complementarity-determining regions (CDR3), while a broad repertoire using different combinations of TCR-α/β V and J segments and CDR3 regions was selected by the immunodominant epitope (EBNA4 416-424, designated IVT). Distinct patterns of interaction with the A11–peptide complex were revealed for each AVF- or IVT-specific TCR clonotype by alanine scanning mutagenesis analysis. Blocking of cytotoxic function by antibodies specific for the CD8 coreceptor indicated that, while AVF-specific TCRs are of high affinity, the oligoclonal response to the IVT epitope includes both low- and high-affinity TCRs. Thus, comparison of the memory response to two epitopes derived from the same viral antigen and presented through the same MHC class I allele suggests that immunodominance may correlate with the capacity to maintain a broad TCR repertoire.
Overexpression of Natural Killer T Cells Protects Vα14-Jα281 Transgenic Nonobese Diabetic Mice against Diabetes
Authors: Lehuen Agnès , Lantz Olivier , Beaudoin Lucie , Laloux Véronique , Carnaud Claude , Bendelac Albert , Bach Jean-François , Monteiro Renato C.
Published: July 2002

Progression to destructive insulitis in nonobese diabetic (NOD) mice is linked to the failure of regulatory cells, possibly involving T helper type 2 (Th2) cells. Natural killer (NK) T cells might be involved in diabetes, given their deficiency in NOD mice and the prevention of diabetes by adoptive transfer of α/β double-negative thymocytes. Here, we evaluated the role of NK T cells in diabetes by using transgenic NOD mice expressing the T cell antigen receptor (TCR) α chain Vα14-Jα281 characteristic of NK T cells. Precise identification of NK1.1+ T cells was based on out-cross with congenic NK1.1 NOD mice. All six transgenic lines showed, to various degrees, elevated numbers of NK1.1+ T cells, enhanced production of interleukin (IL)-4, and increased levels of serum immunoglobulin E. Only the transgenic lines with the largest numbers of NK T cells and the most vigorous burst of IL-4 production were protected from diabetes. Transfer and cotransfer experiments with transgenic splenocytes demonstrated that Vα14-Jα281 transgenic NOD mice, although protected from overt diabetes, developed a diabetogenic T cell repertoire, and that NK T cells actively inhibited the pathogenic action of T cells. These results indicate that the number of NK T cells strongly influences the development of diabetes.
Cryptococcus neoformans STE12α Regulates Virulence but Is Not Essential for Mating
Authors: Chang Y.C. , Wickes B.L. , Miller G.F. , Penoyer L.A. , Kwon-Chung K.J.
Published: July 2002

The Cryptococcus neoformans STE12α gene, a homologue of Saccharomyces cerevisiae STE12, exists only in mating type (MAT)α cells. In S. cerevisiae, STE12 was required for mating and filament formation. In C. neoformans, haploid fruiting on filament agar required STE12α. The ability to form hyphae, however, was not affected by deletion of STE12α when convergently growing MATa strains were present. Furthermore, ste12α disruptants were fertile when mated with MATa strains, albeit with reduced mating frequency. Most importantly, the virulence of a ste12α disruptant of serotype D strain was significantly reduced in a mouse model. When the ste12α locus was reconstituted with the wild-type allele by cotransformation, virulence was restored. Histopathological analysis demonstrated a reduction in capsular size of yeast cells, less severe cystic lesions, and stronger immune responses in meninges of mice infected with ste12α cells than those of mice infected with STE12α cells. Using reporter gene constructs, we found that STE12α controls the expression of several phenotypes known to be involved in virulence, such as capsule and melanin production. These results demonstrate a clear molecular link between mating type and virulence in C. neoformans.
Molecular Basis for Leukocyte Integrin αEβ7 Adhesion to Epithelial (E)-Cadherin
Authors: Taraszka Karen S. , Higgins Jonathan M.G. , Tan Kemin , Mandelbrot Didier A. , Wang Jia-huai , Brenner Michael B.
Published: July 2002

Cadherins are expressed in tissue-restricted patterns and typically mediate homophilic adhesion. Cadherins also mediate lymphocyte adhesion, providing the opportunity for lymphocyte attachment to parenchymal cells. The best characterized example of lymphocyte adhesion to a tissue-specific cell adhesion molecule, as opposed to a vascular endothelial adhesion molecule, is the interaction between integrin αEβ7 on intraepithelial lymphocytes and E-cadherin on epithelial cells. However, the molecular basis for an integrin–cadherin interaction is not well defined. Realization that the cadherin domain adopts a topology similar to the immunoglobulin (Ig) fold suggested that integrin recognition of E-cadherin might be similar to recognition of Ig superfamily ligands. Thus, we modeled domain 1 of human E-cadherin and studied the role of solvent-exposed loops that connect Ig-like core-forming β strands. Mutational analyses localized the integrin αEβ7 recognition site to the top of domain 1 at the face formed by the BC and FG loops, a site distinct from the region recognized in intercellular adhesion molecule (ICAM)-1, -2, and -3, mucosal addressin cell adhesion molecule 1 (MAdCAM-1), vascular cell adhesion molecule 1 (VCAM-1), and fibronectin by their integrin ligands. Moreover, the integrin αEβ7 binding site is distinct from the homophilic binding site on E-cadherin. These studies provide a conceptual basis for integrin–cadherin binding and extend the model that an Ig-like fold can serve as a scaffold for recognition.
Annexins V and Xii Alter the Properties of Planar Lipid Bilayers Seen by Conductance Probes
Authors: Sokolov Yuri , Mailliard William S. , Tranngo Nghia , Isas Mario , Luecke Hartmut , Haigler Harry T. , Hall James E.
Published: July 2002

Annexins are proteins that bind lipids in the presence of calcium. Though multiple functions have been proposed for annexins, there is no general agreement on what annexins do or how they do it. We have used the well-studied conductance probes nonactin, alamethicin, and tetraphenylborate to investigate how annexins alter the functional properties of planar lipid bilayers. We found that annexin XII reduces the nonactin-induced conductance to ∼30% of its original value. Both negative lipid and ∼30 μM Ca2+ are required for the conductance reduction. The mutant annexin XIIs, E105K and E105K/K68A, do not reduce the nonactin conductance even though both bind to the membrane just as wild-type does. Thus, subtle changes in the interaction of annexins with the membrane seem to be important. Annexin V also reduces nonactin conductance in nearly the same manner as annexin XII. Pronase in the absence of annexin had no effect on the nonactin conductance. But when added to the side of the bilayer opposite that to which annexin was added, pronase increased the nonactin-induced conductance toward its pre-annexin value. Annexins also dramatically alter the conductance induced by a radically different probe, alamethicin. When added to the same side of the bilayer as alamethicin, annexin has virtually no effect, but when added trans to the alamethicin, annexin dramatically reduces the asymmetry of the I-V curve and greatly slows the kinetics of one branch of the curve without altering those of the other. Annexin also reduces the rate at which the hydrophobic anion, tetraphenylborate, crosses the bilayer. These results suggest that annexin greatly reduces the ability of small molecules to cross the membrane without altering the surface potential and that at least some fraction of the active annexin is accessible to pronase digestion from the opposite side of the membrane.
An arithmetic obstruction to division algebra decomposability
Authors: Brussel Eric
Published: July 2002

This paper presents an indecomposable finite-dimensional division algebra of

p
p

-power index that decomposes over a prime-to-

p
p

degree field extension, obtained by adjoining

p
p

-th roots of unity to the base. This shows that the theory of decomposability has an arithmetic aspect.
Integral representation of linear functionals on spaces of unbounded functions
Authors: Berti Patrizia , Rigo Pietro
Published: July 2002

Let

L
L

be a vector lattice of real functions on a set

Ω
\Omega

with

1
∈
L

\boldsymbol {1}\in L

, and let

P
P

be a linear positive functional on

L
L

. Conditions are given which imply the representation

P
(
f
)
=
∫
f
d
π

P(f)=\int fd\pi

,

f
∈
L

f\in L

, for some bounded charge

π
\pi

. As an application, for any bounded charge

π
\pi

on a field

F

\mathcal F

, the dual of

L
1

(
π
)

L^1(\pi )

is shown to be isometrically isomorphic to a suitable space of bounded charges on

F

\mathcal F

. In addition, it is proved that, under one more assumption on

L
L

,

P
P

is the integral with respect to a

σ
\sigma

-additive bounded charge.
Constructing the Kähler and the symplectic structures from certain spinors on 4-manifolds
Authors: Byun Y. , Lee Y. , Park J. , Ryu J.
Published: July 2002

We show that, on an oriented Riemannian 4-manifold, existence of a non-zero parallel spinor with respect to a spinc^cstructure implies that the underlying smooth manifold admits a Kähler structure. A similar but weaker condition is obtained for the 4-manifold to admit a symplectic structure. We also show that thespincspin^cstructure in which the non-zero parallel spinor lives is equivalent to the canonical spinc^cstructure associated to the Kähler structure.
Bloch constants for planar harmonic mappings
Authors: Chen Huaihui , Gauthier P. , Hengartner W.
Published: July 2002

We give a lower estimate for the Bloch constant for planar harmonic mappings which are quasiregular and for those which are open. The latter includes the classical Bloch theorem for holomorphic functions as a special case. Also, for bounded planar harmonic mappings, we obtain results similar to a theorem of Landau on bounded holomorphic functions.
A continuous decomposition of the Menger curve into pseudo-arcs
Authors: Prajs Janusz
Published: July 2002

It is proved that the Menger universal curve

M

\mathcal {M}

admits a continuous decomposition into pseudo-arcs with the quotient space homeomorphic to

M

\mathcal {M}

.
A short proof of Ellentuck’s Theorem
Authors: Matet Pierre
Published: July 2002

We combine standard arguments to give a shorter proof of Ellentuck’s Theorem.
The Bieri-Neumann-Strebel invariant for basis-conjugating automorphisms of free groups
Authors: Orlandi-Korner Lisa
Published: July 2002

The pure symmetric automorphism group of the free group on

n
n

generators,

P

Σ
n

P\Sigma _n

, consists of those automorphisms which take each generator to a conjugate of itself. We describe the Bieri-Neumann-Strebel invariant of

P

Σ
n

P\Sigma _n

, which determines, among other things, which subgroups containing the commutator are finitely generated.
A functional equation arising from ranked additive and separable utility
Authors: Aczél János , Maksa Gyula , Ng Che , Páles Zsolt
Published: July 2002

All strictly monotonic solutions of a general functional equation are determined. In a particular case, which plays an essential role in the axiomatization of rank-dependent expected utility, all nonnegative solutions are obtained without any regularity conditions. An unexpected possibility of reduction to convexity makes the present proof possible.
Essentiality for Mönch type maps
Authors: Agarwal Ravi , O’Regan Donal
Published: July 2002

A new fixed point theorem for Mönch maps on locally convex spaces is given. In addition, a continuation theorem for Mönch maps is presented.
A formula for 𝑘-hyponormality of backstep extensions of subnormal weighted shifts
Authors: Jung Il , Li Chunji
Published: July 2002

Let

α

:

α

0

,

α

1

,
⋯

{\alpha }: {\alpha }_{0}, {\alpha }_{1}, \cdots

be a weight sequence of positive real numbers and let

W

α

W_{{\alpha }}

be a subnormal weighted shift with a weight sequence

α
\alpha

. Consider an extended weight sequence

α

(
x
)
:
x
,

α

0

,

α

1

,
⋯

{\alpha }(x) : x, {\alpha }_{0}, {\alpha }_{1}, \cdots

with

0
>
x
≤

α

0

0>x \le \alpha _{0}

and let

H
E
(

α
,
k

)
:=
{
x
>
0
:

W

α
(
x
)

 
is
 
k
-hyponormal
}

HE({\alpha ,k}):= \{ x >0: W_{\alpha (x)}\ \text {is} \ k \text {-hyponormal}\}

for

k
∈

N

∪
{
∞
}

k \in {\mathbb {N}}\cup \{\infty \}

, where

N

\mathbb {N}

is the set of natural numbers. We obtain a formula to find the interval

H
E
(

α
,
k

)
∖
H
E
(

α
,
k
+
1

)

HE({\alpha ,k})\setminus HE({\alpha ,k+1})

, which provides several examples to distinguish the classes of

k
k

-hyponormal operators from one another.
Validity of nonlinear geometric optics with times growing logarithmically
Authors: Lannes David , Rauch Jeffrey
Published: July 2002

The profiles (a.k.a. amplitudes) which enter in the approximate solutions of nonlinear geometric optics satisfy equations, sometimes called the slowly varying amplitude equations, which are simpler than the original hyperbolic systems. When the underlying problem is conservative one often finds that the amplitudes are defined for all time and are uniformly bounded. The approximations of nonlinear geometric optics typically have percentage error which tends to zero uniformly on bounded time intervals as the wavelength

ϵ
\epsilon

tends to zero. Under suitable hypotheses when the amplitude is uniformly bounded in space and time we show that the percentage error tends to zero uniformly on time intervals

[
0
,
C

|

ln
⁡
ϵ

|

]

[0,C|\ln \epsilon |]

which grow logarithmically. The proof relies in an essential way on the fact that one has a corrector to the leading term of geometric optics.
Finite dimensional injective operator spaces
Authors: Smith Roger
Published: July 2002

We show that finite dimensional injective operator spaces are corners

p

A

p

⊥

p\mathcal {A} p^{\perp }

of finite dimensional

C
∗

C^*

-algebras

A

\mathcal {A}

.
Criteria of Pólya type for radial positive definite functions
Authors: Gneiting Tilmann
Published: July 2002

This article presents sufficient conditions for the positive definiteness of radial functions

f
(
x
)
=
φ
(
‖
x
‖
)

f(x) = \varphi (\|x\|)

,

x
∈

R

n

x \in \mathbb {R}^n

, in terms of the derivatives of

φ
\varphi

. The criterion extends and unifies the previous analogues of Pólya’s theorem and applies to arbitrarily smooth functions. In particular, it provides upper bounds on the Kuttner-Golubov function

k
n

(
λ
)

k_n(\lambda )

which gives the minimal value of

κ
\kappa

such that the truncated power function

(
1
−
‖
x

‖
λ

)
+
κ

(1-\|x\|^\lambda )_+^\kappa

,

x
∈

R

n

x \in \mathbb {R}^n

, is positive definite. Analogous problems and criteria of Pólya type for

‖
⋅

‖
α

\|\cdot \|_\alpha

-dependent functions,

α
>
0

\alpha > 0

, are also considered.
Isometric submersions of Finsler manifolds
Authors: Álvarez Paiva J. , Durán C.
Published: July 2002

The notion of isometric submersion is extended to Finsler spaces and it is used to construct examples of Finsler metrics on complex and quaternionic projective spaces all of whose geodesics are (geometrical) circles.
Equivalence of positive Hausdorff measure and the open set condition for self-conformal sets
Authors: Peres Yuval , Rams Michał , Simon Károly , Solomyak Boris
Published: July 2002

A compact set

K
K

is self-conformal if it is a finite union of its images by conformal contractions. It is well known that if the conformal contractions satisfy the “open set condition” (OSC), then

K
K

has positive

s
s

-dimensional Hausdorff measure, where

s
s

is the solution of Bowen’s pressure equation. We prove that the OSC, the strong OSC, and positivity of the

s
s

-dimensional Hausdorff measure are equivalent for conformal contractions; this answers a question of R. D. Mauldin. In the self-similar case, when the contractions are linear, this equivalence was proved by Schief (1994), who used a result of Bandt and Graf (1992), but the proofs in these papers do not extend to the nonlinear setting.
Invariant ideals of abelian group algebras under the multiplicative action of a field. I
Authors: Passman D. , Zalesskiĭ A.
Published: July 2002

Let

D
D

be a division ring and let

V
=

D
n

V=D^n

be a finite-dimensional

D
D

-vector space, viewed multiplicatively. If

G
=

D
∙

G=D^\bullet

is the multiplicative group of

D
D

, then

G
G

acts on

V
V

and hence on any group algebra

K
[
V
]

K[V]

. Our goal is to completely describe the semiprime

G
G

-stable ideals of

K
[
V
]

K[V]

. As it turns out, this result follows fairly easily from the corresponding results for the field of rational numbers (due to Brookes and Evans) and for infinite locally-finite fields. Part I of this work is concerned with the latter situation, while Part II deals with arbitrary division rings.
A question of B. Plotkin about the semigroup of endomorphisms of a free group
Authors: Formanek Edward
Published: July 2002

Let

F
F

be a free group of finite rank

n
≥
2

n \geq 2

, let

E
n
d
(
F
)

End(F)

be the semigroup of endomorphisms of

F
F

, and let

A
u
t
(
F
)

Aut(F)

be the group of automorphisms of

F
F

. Theorem. If

T
:
E
n
d
(
F
)
→
E
n
d
(
F
)

T : End(F) \to End(F)

is an automorphism of

E
n
d
(
F
)

End(F)

, then there is an

α
∈
A
u
t
(
F
)

\alpha \in Aut(F)

such that

T
(
β
)
=
α
∘
β
∘

α

−
1

T(\beta ) = \alpha \circ \beta \circ \alpha ^{-1}

for all

β
∈
E
n
d
(
F
)

\beta \in End(F)

.
Natural examples of Π₅⁰-complete sets in analysis
Authors: Sofronidis Nikolaos
Published: July 2002

The purpose of this paper is to show that given any non-negative real number

α
\alpha

, the set of entire functions whose order is equal to

α
\alpha

is

Π

3

0

\boldsymbol {\Pi }_{3}^{0}

-complete, and the set of all sequences of entire functions whose orders converge to

α
\alpha

is

Π

5

0

\boldsymbol {\Pi }_{5}^{0}

-complete.
Central limit theorem for Banach space valued fuzzy random variables
Authors: Proske Frank , Puri Madan
Published: July 2002

In this paper we prove a central limit theorem for Borel measurable nonseparably valued random elements in the case of Banach space valued fuzzy random variables.
On the failure of the factorization condition for non-degenerate Fourier integral operators
Authors: Ruzhansky Michael
Published: July 2002

In this paper we give examples of polynomial phase functions for which the factorization condition of Seeger, Sogge and Stein (Ann. Math. 134 (1991)) fails. The corresponding Fourier integral operators turn out to be still continuous in

L
p

L^p

. We also give examples of the failure of the factorization condition for translation invariant operators. In this setting the frequency space must be at least 5-dimensional, which shows that the examples are optimal. We briefly discuss the stationary phase method for the corresponding operators.
On translations of subsets of the real line
Authors: Cichoń Jacek , Jasiński Andrzej , Kamburelis Anastasis , Szczepaniak Przemysław
Published: July 2002

In this paper we discuss various questions connected with translations of subsets of the real line. Most of these questions originate from W. Sierpiński. We discuss the number of translations a single subset of the reals may have. Later we discuss almost invariant subsets of Abelian groups.
Schur orthogonality relations and invariant sesquilinear forms
Authors: Donley Robert
Published: July 2002

Important connections between the representation theory of a compact group

G
G

and

L

2

(
G
)

L^{2}(G)

are summarized by the Schur orthogonality relations. The first part of this work is to generalize these relations to all finite-dimensional representations of a connected semisimple Lie group

G
.

G.

The second part establishes a general framework in the case of unitary representations

(
π
,
V
)

(\pi , V)

of a separable locally compact group. The key step is to identify the matrix coefficient space with a dense subset of the Hilbert-Schmidt endomorphisms on

V
V

.
Ultrastability of ideals of homogeneous polynomials and multilinear mappings on Banach spaces
Authors: Floret Klaus , Hunfeld Stephan
Published: July 2002

Using the theory of full and symmetric tensor norms on normed spaces, a theorem of Kürsten and Heinrich on ultrastability and maximality of normed operator ideals is extended to ideals ofnn-homogeneous polynomials andnn-linear mappings—scalar-valued and vector-valued. The motivation for these results is the following important special case: the “uniterated” Aron-Berner extensionq¯U\overline {q}^{\mathfrak U}:E⟶FE \longrightarrow Fof annn-homogeneous polynomialq:E⟶Fq: E\longrightarrow Fto the bidual remains in certain ideals under preservation of the norm. Moreover, Lotz’s characterization of maximal normed ideals of linear mappings through appropriate tensor norms is proved for ideals ofnn-homogeneous scalar-valued polynomials and ideals ofnn-linear mappings.
The homogeneous spectrum of a graded commutative ring
Authors: Heinzer William , Roitman Moshe
Published: July 2002

Suppose

Γ
\Gamma

is a torsion-free cancellative commutative monoid for which the group of quotients is finitely generated. We prove that the spectrum of a

Γ
\Gamma

-graded commutative ring is Noetherian if its homogeneous spectrum is Noetherian, thus answering a question of David Rush. Suppose

A
A

is a commutative ring having Noetherian spectrum. We determine conditions in order that the monoid ring

A
[
Γ
]

A[\Gamma ]

have Noetherian spectrum. If

rank
⁡
Γ
≤
2

\operatorname {rank} \Gamma \le 2

, we show that

A
[
Γ
]

A[\Gamma ]

has Noetherian spectrum, while for each

n
≥
3

n \ge 3

we establish existence of an example where the homogeneous spectrum of

A
[
Γ
]

A[\Gamma ]

is not Noetherian.
On the irreducibility of the iterates of 𝑥ⁿ-𝑏
Authors: Danielson Lynda , Fein Burton
Published: July 2002

Let

K
K

be a field and suppose that

f
(
x
)
=

x

n

−
b

f(x)=x^{n}-b

is irreducible in

K
[
x
]

K[x]

. We discuss the following question: under what conditions are all iterates of

f
f

irreducible over

K
K

?
LCM-splitting sets in some ring extensions
Authors: Dumitrescu Tiberiu , Zafrullah Muhammad
Published: July 2002

Let

S
S

be a saturated multiplicative set of an integral domain

D
D

. Call

S
S

an lcm splitting set if

d

D

S

∩
D

dD_{S}\cap D

and

d
D
∩
s
D

dD\cap sD

are principal ideals for every

d
∈
D

d\in D

and

s
∈
S

s\in S

. We show that if

R
R

is an

R

2

R_{2}

-stable overring of

D
D

(that is, if whenever

a
,
b
∈
D

a,b\in D

and

a
D
∩
b
D

aD\cap bD

is principal, it follows that

(
a
D
∩
b
D
)
R
=
a
R
∩
b
R
)

(aD\cap bD)R=aR\cap bR)

and if

S
S

is an lcm splitting set of

D
D

, then the saturation of

S
S

in

R
R

is an lcm splitting set in

R
R

. Consequently, if

D
D

is Noetherian and

p
∈
D

p\in D

is a (nonzero) prime element, then

p
p

is also a prime element of the integral closure of

D
D

. Also, if

D
D

is Noetherian,

S
S

is generated by prime elements of

D
D

and if the integral closure of

D

S

D_{S}

is a UFD, then so is the integral closure of

D
D

.
Lower estimate for the integral means spectrum for 𝑝=-1
Authors: Kayumov Ilgiz
Published: July 2002

In this paper we show that there exists a function

f
f

bounded and univalent in the unit disk, such that
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="integral StartAbsoluteValue f prime left-parenthesis r e Superscript i theta Baseline right-parenthesis EndAbsoluteValue Superscript negative 1 Baseline d theta greater-than-or-equal-to upper C left-parenthesis 1 minus r right-parenthesis Superscript negative 0.127">

∫

|

f
′

(
r

e

i
θ

)

|

−
1

d
θ
≥
C
(
1
−
r

)

−
0.127

\int |f’(re^{i\theta })|^{-1}d\theta \ge C(1-r)^{-0.127}

,

0
≤
r
>
1.

0 \leq r >1.
A remark on Calderón-Zygmund classes and Sobolev spaces
Authors: Swanson David
Published: July 2002

We show how the Sobolev space

W

k
,
p

(

R

n

)

W^{k,p}(\mathbf {R}^n)

may be characterized in terms of the local behavior of its members. We use the local

T

k
,
p

T^{k,p}

-classes introduced by Calderón and Zygmund.
Linearity of dimension functions for semilinear 𝐺-spheres
Authors: Nagasaki Ikumitsu
Published: July 2002

In this paper, we show that the dimension function of every semilinear

G
G

-sphere is equal to that of a linear

G
G

-sphere for finite nilpotent groups

G
G

of order

p
n

q
m

p^nq^m

, where

p
p

,

q
q

are primes. We also show that there exists a semilinear

G
G

-sphere whose dimension function is not virtually linear for an arbitrary nonsolvable compact Lie group

G
G

.
On factor states of 𝐶*-algebras and their extensions
Authors: Chu Cho-Ho , Kusuda Masaharu
Published: July 2002

We obtain some results on the unique extension of (factor) states of

C
∗

C^*

-algebras which complement various existing results. Our results also lead to a class of

C
∗

C^*

-algebras whose states are

σ
\sigma

-convex sums of factor states.
Orientation-preserving self-homeomorphisms of the surface of genus two have points of period at most two
Authors: Dicks Warren , Llibre Jaume
Published: July 2002

We show that for any orientation-preserving self-homeomorphism

α
\alpha

of the double torus

Σ

2

\Sigma _{2}

there exists a point

p
p

of

Σ

2

\Sigma _{2}

such that

α
(
α
(
p
)
)
=
p

\alpha (\alpha (p)) = p

. This answers a question raised by Jakob Nielsen in 1942.
Inversion formula and singularities of the solution for the backprojection operator in tomography
Authors: Ramm A.
Published: July 2002

Let

R
∗

μ
:=

∫

S
2

μ
(
α
,
α
⋅
x
)
d
α

R^\ast \mu := \int _{S^2} \mu (\alpha , \alpha \cdot x) d\alpha

,

x
∈

R

n

x \in {\mathbb {R}}^n

, be the backprojection operator. The range of this operator as an operator on non-smooth functions
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper R Superscript asterisk Baseline colon upper X colon equals upper L 0 Superscript normal infinity Baseline left-parenthesis upper S Superscript n minus 1 Baseline times double-struck upper R right-parenthesis right-arrow upper L Subscript normal l normal o normal c Superscript 2 Baseline left-parenthesis double-struck upper R Superscript n Baseline right-parenthesis">

R
∗

:
X
:=

L
0
∞

(

S

n
−
1

×

R

)
→

L

l
o
c

2

(

R

n

)

R^\ast : X:=L^\infty _0 (S^{n-1} \times {\mathbb {R}}) \to L_{\mathrm {loc}}^2 ({\mathbb {R}}^n)

is described and formulas for

(

R
∗

)

−
1

(R^\ast )^{-1}

are derived. It is proved that the operator

R
∗

R^\ast

is not injective on

X
X

but is injective on the subspace

X
e

X_e

of

X
X

which consists of even functions

μ
(
α
,
p
)
=
μ
(
−
α
,
−
p
)

\mu (\alpha , p) = \mu (-\alpha , -p)

. Singularities of the function

(

R
∗

)

−
1

h

(R^\ast )^{-1} h

are studied. Here

h
h

is a piecewise-smooth compactly supported function. Conditions for

μ
\mu

to have compact support are given. Some applications are considered.
Geometry of Kodaira moduli spaces
Authors: Merkulov Sergey
Published: July 2002

A general theorem on the existence of natural torsion-free affine connections on a complete family of compact complex submanifolds in a complex manifold is proved.
Products of 𝜔* images
Authors: Bell M. , Shapiro L. , Simon P.
Published: July 2002

Let

ω
∗

\omega ^*

be the C̆ech-Stone remainder

β
ω
∖
ω

\beta \omega \setminus \omega

. We show that there exists a large class

O

\mathcal {O}

of images of

ω
∗

\omega ^*

such that whenever

S

\mathcal {S}

is a subset of

O

\mathcal {O}

of cardinality at most the continuum, then

ω
∗

×
∏

S

\omega ^* \times \prod \mathcal {S}

is again an image of

ω
∗

\omega ^*

. The class

O

\mathcal {O}

contains all separable compact spaces, all compact spaces of weight at most

ω
1

\omega _1

and all perfectly normal compact spaces.
A counterexample to Cartan’s conjecture on holomorphic curves omitting hyperplanes
Authors: Eremenko Alexandre
Published: July 2002

In his 1928 thesis H. Cartan proved a theorem which can be considered as an extension of Montel’s normality criterion to holomorphic curves in complex projective plane

P

2

\mathbf {P}^2

. He also conjectured that a similar result is true for holomorphic curves in

P

n

\mathbf {P}^n

for any

n
n

. A counterexample to this conjecture is constructed for any

n
≥
3

n\geq 3

.
Bounded eigenfunctions and absolutely continuous spectra for one-dimensional Schrödinger operators
Authors: Simon Barry
Published: July 2002

We provide a short proof of that case of the Gilbert-Pearson theorem that is most often used: That all eigenfunctions bounded implies purely a.c. spectrum. Two appendices illuminate Weidmann’s result that potentials of bounded variation have strictly a.c. spectrum on a half-axis.
Q.U.P. and Paley-Wiener properties of unimodular, especially nilpotent, Lie groups
Authors: Arnal Didier , Ludwig Jean
Published: July 2002

We give a new proof of a weak Paley-Wiener theorem for nilpotent Lie groups due to Lipsman and Rosenberg and we introduce a general notion of Q.U.P for any unimodular locally compact group.
Continuous Fell bundles associated to measurable twisted actions
Authors: Exel Ruy , Laca Marcelo
Published: July 2002

Given a measurable twisted action of a second-countable, locally compact group

G
G

on a separable

C

∗

C^{*}

-algebra

A
A

, we prove the existence of a topology on

A
×
G

A\times G

making it a continuous Fell bundle, whose cross sectional

C

∗

C^{*}

-algebra is isomorphic to the Busby–Smith–Packer–Raeburn crossed product.
On the non-existence of homoclinic orbits for a class of infinite dimensional Hamiltonian systems
Authors: Clément Ph. , van der Vorst R.
Published: July 2002

We prove that for a class of infinite dimensional Hamiltonian systems certain homoclinic connections to the origin cease to exist when the non-linearities have ‘super-critical’ growth. The proof is based on a variational principle and a Pohožaev type identity.
Upper bounds for the number of facets of a simplicial complex
Authors: Herzog Jürgen , Hibi Takayuki
Published: July 2002

Here we study the maximal dimension of the annihilator ideals

0

:

A

m

j

0:_{A}m^{j}

of artinian graded rings

A
=
P

/

(
I
,

x
1
2

,

x
2
2

,
…
,

x
v
2

)

A = P / (I, x_1^2, x_2^2, \ldots , x_v^2)

with a given Hilbert function, where

P
P

is the polynomial ring in the variables

x
1

,

x
2

,
…
,

x
v

x_1, x_2, \ldots , x_v

over a field

K
K

with each

deg
⁡

x
i

=
1

\deg x_i = 1

,

I
I

is a graded ideal of

P
P

, and

m
m

is the graded maximal ideal of

A
A

. As an application to combinatorics, we introduce the notion of

j
j

-facets and obtain some informations on the number of

j
j

-facets of simplicial complexes with a given

f
f

-vector.
Amenable representations and finite injective von Neumann algebras
Authors: Valette Alain
Published: July 2002

Let

U
(
M
)

U(M)

be the unitary group of a finite, injective von Neumann algebra

M
M

. We observe that any subrepresentation of a group representation into

U
(
M
)

U(M)

is amenable in the sense of Bekka; this yields short proofs of two known results—one by Robertson, one by Haagerup—concerning group representations into

U
(
M
)

U(M)

.
Convexity and Haar null sets
Authors: Matoušková Eva
Published: July 2002

It is shown that for every closed, convex and nowhere dense subset

C
C

of a superreflexive Banach space

X
X

there exists a Radon probability measure

μ
\mu

on

X
X

so that

μ
(
C
+
x
)
=
0

\mu (C+x)=0

for all

x
∈
X

x\in X

. In particular, closed, convex, nowhere dense sets in separable superreflexive Banach spaces are Haar null. This is unlike the situation in separable nonreflexive Banach spaces, where there always exists a closed convex nowhere dense set which is not Haar null.
On Isaacs’ three character degrees theorem
Authors: Berkovich Yakov
Published: July 2002

Isaacs has proved that a finite group

G
G

is solvable whenever there are at most three characters of pairwise distinct degrees in

Irr
⁡
(
G
)

\operatorname {Irr}(G)

(Isaacs’ three character degrees theorem). In this note, using Isaacs’ result and the classification of the finite simple groups, we prove the solvability of

G
G

whenever

Irr
⁡
(
G
)

\operatorname {Irr}(G)

contains at most three monolithic characters of pairwise distinct degrees. §2 contains some additional results about monolithic characters.
Sets of sampling and interpolation in Bergman spaces
Authors: Schuster Alexander
Published: July 2002

Properties of the unions of sampling and interpolation sets for Bergman spaces are discussed in conjunction with the examples given by Seip (1993). Their relationship to the classical interpolation sequences is explored. In addition, the role played by canonical divisors in the study of these sets is examined and an example of a sampling set is constructed in the disk.
A two-parameter “Bergman space” inequality
Authors: Wilson J.
Published: July 2002

For

f
∈

L

1

(
[
0
,
1
]
×
[
0
,
1
]
)

f\in L^{1}([0,1]\times [0,1])

, define

λ

R

≡
⟨
f
,

h

(
R
)

⟩

\lambda _{R} \equiv \langle f,h_{(R)}\rangle

, where
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="h Subscript left-parenthesis upper R right-parenthesis Baseline left-parenthesis x comma y right-parenthesis equals h Subscript left-parenthesis upper I right-parenthesis Baseline left-parenthesis x right-parenthesis dot h Subscript left-parenthesis upper J right-parenthesis Baseline left-parenthesis y right-parenthesis">

h

(
R
)

(
x
,
y
)
=

h

(
I
)

(
x
)
⋅

h

(
J
)

(
y
)

h_{(R)}(x,y)=h_{(I)}(x)\cdot h_{(J)}(y)

is a tensor product of one-parameter Haar functions. Let

1
>
p
≤
q
>
∞

1>p\leq q>\infty

and

q
≥
2

q\geq 2

. We prove a sufficient condition, which is close to necessary, on double sequences of weights

{

μ

R

}

R

\{\mu _{R}\}_{R}

and non-negative

v
∈

L

1

(
[
0
,
1
]
×
[
0
,
1
]
)

v\in L^{1}([0,1]\times [0,1])

, which ensures that the inequality
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="left-parenthesis sigma-summation Underscript upper R Endscripts StartAbsoluteValue lamda Subscript upper R Baseline EndAbsoluteValue Superscript q Baseline mu Subscript upper R Baseline right-parenthesis Superscript 1 slash q Baseline less-than-or-equal-to left-parenthesis integral Underscript left-bracket 0 comma 1 right-bracket times left-bracket 0 comma 1 right-bracket Endscripts StartAbsoluteValue f EndAbsoluteValue Superscript p Baseline v d x right-parenthesis Superscript 1 slash p">

(

∑

R

|

λ

R

|

q

μ

R

)

1

/

q

≤

(

∫

[
0
,
1
]
×
[
0
,
1
]

|

f

|

p

v

d
x
)

1

/

p

\begin{equation*} \left (\sum _{R}\vert {\lambda _{R}}\vert ^{q}\mu _{R}\right )^{1/q}\leq \left (\int _{[0,1]\times [0,1]}\vert {f}\vert ^{p}\, v\, dx\right )^{1/p}\end{equation*}

holds for all

f
∈

L

1

(
[
0
,
1
]
×
[
0
,
1
]
)

f\in L^{1}([0,1]\times [0,1])

. We extend our result to an inequality concerning two-parameter wavelet families.
Infinitely renormalizable diffeomorphisms of the disk at the boundary of chaos
Authors: Catsigeras Eleonora , Gambaudo Jean-Marc , Moreira Fernando
Published: July 2002

We show that, among area contracting embeddings of the 2-disk, infinitely renormalizable maps with a bounded geometry either have positive topological entropy or correspond to a cascade of period doubling.
Une remarque sur l’orthogonalité de l’image au noyau d’une dérivation généralisée
Authors: Delai M. , Bouali S. , Cherki S.
Published: July 2002

In this paper we introduce the notion of the pair

(
A
,
B
)

(A,B)

of operators having the Fuglede-Putnam property in a two-sided ideal of

L
(
H
)

L(H)

. The characterization of this class allows us to generalize the recent result of F. Kittaneh. We also give some applications of this result.
On the interior derivative blow-up for the curvature evolution of capillary surfaces
Authors: Asai Keisui , Ishimura Naoyuki
Published: July 2002

We give examples of the interior derivative blow-up solutions for the curvature evolution of capillary surfaces over a bounded domain in

R

N

\mathbf {R}^{N}

.
Cardinal invariants concerning bounded families of extendable and almost continuous functions
Authors: Ciesielski Krzysztof , Maliszewski Aleksander
Published: July 2002

In this paper we introduce and examine a cardinal invariant 

A

b

\operatorname {A}_{{b}}

closely connected to the addition of bounded functions from

R

\mathbb {R}

to 

R

\mathbb {R}

. It is analogous to the invariant 

A
\operatorname {A}

defined earlier for arbitrary functions by T. Natkaniec. In particular, it is proved that each bounded function can be written as the sum of two bounded almost continuous functions, and an example is given that there is a bounded function which cannot be expressed as the sum of two bounded extendable functions.