bluuebunny/crossref_metadata_2025 huggingface dataset:
The interaction of diadenosine polyphosphates with P2X‐receptors in the guinea‐pig isolated vas deferens
Authors: Westfall T D , McIntyre C A , Obeid S , Bowes J , Kennedy C , Sneddon P
Published: August 2006

The site(s) at which diadenosine 5′,5′′′‐P1, P4‐tetraphosphate (AP4A) and diadenosine 5′, 5′′′‐P1, P5‐pentaphosphate (AP5A) act to evoke contraction of the guinea‐pig isolated vas deferens was studied by use of a series of P2‐receptor antagonists and the ecto‐ATPase inhibitor 6‐N, N‐diethyl‐D‐β,γ‐dibromomethyleneATP (ARL 67156).

Pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS) (300 nM–30 μM), suramin (3–100 μM) and pyridoxal‐5′‐phosphate (P‐5‐P) (3–1000 μM) inhibited contractions evoked by equi‐effective concentrations of AP5A (3 μM), AP4A (30 μM) and α,β‐methyleneATP (α,β‐meATP) (1 μM), in a concentration‐dependent manner and abolished them at the highest concentrations used.

PPADS was more potent than suramin, which in turn was more potent than P‐5‐P. PPADS inhibited AP5A, AP4A and α,β‐meATP with similar IC50 values. No significant difference was found between IC50 values for suramin against α,β‐meATP and AP5A or α,β‐meATP and AP4A, but suramin was more than 2.5 times more potent against AP4A than AP5A. P‐5‐P showed the same pattern of antagonism.

Desensitization of the P2X1‐receptor by α,β‐meATP abolished contractions evoked by AP5A (3 μM) and AP4A (30 μM), but had no effect on those elicited by noradrenaline (100 μM).

ARL 67156 (100 μM) reversibly potentiated contractions evoked by AP4A (30 μM) by 61%, but caused a small, significant decrease in the mean response to AP5A (3 μM).

It is concluded that AP4A and AP5A act at the P2X1‐receptor, or a site similar to the P2X1‐receptor, to evoke contraction of the guinea‐pig isolated vas deferens. Furthermore, the potency of AP4A, but not AP5A, appears to be inhibited by an ecto‐enzyme which is sensitive to ARL 67156.

British Journal of Pharmacology (1997) 121, 57–62; doi:10.1038/sj.bjp.0701099
Inhibition by singlet molecular oxygen of the vascular reactivity in rabbit mesenteric artery
Authors: Mizukawa Hisae , Okabe Eiichiro
Published: August 2006

The effects of reactive oxygen intermediates derived from photoactivated rose bengal on the vascular reactivity have been evaluated in rabbit mesenteric artery ring preparations. The artery rings were exposed to xanthene dye rose bengal (50 nM) illuminated (6,000 lux) at 560 nm for 30 min. Spin trapping studies with 2,2,6,6‐tetramethylpiperidine (TEMP) and 5,5‐dimethyl‐1‐pyrroline‐N‐oxide (DMPO) with electron spin resonance spectrometry were also conducted in solution (and not within tissues) to determine quantitatively the reactive oxygen species generated from photoactivated rose bengal.

Contraction of the ring preparations induced by noradrenaline (10−8 to 10−4 M) was attenuated by previous exposure to photolysed rose bengal; the observation that the pD2 decreased without a significant reduction in maximum tension generation is consistent with the view that receptor dysfunction may be involved in the effect of photolysed rose bengal.

Prior exposure to photolysed rose bengal of the ring preparations inhibited the endothelium‐dependent relaxation evoked by acetylcholine (10−6 M) and calcium ionophore A23187 (10−7 M), but not the endothelium‐independent relaxation evoked by nitroglycerin (10−6 M).

A variety of scavengers, superoxide dismutase (33 units ml−1), catalase (32 units ml−1) and 1,3‐dimethyl‐2‐thiourea (DMTU, 10 mM), which should eliminate the superoxide anion radical, H2O2 and the hydroxyl radical, had no effect on the attenuated responses to noradrenaline and acetylcholine induced by photolysed rose bengal. In contrast, the inhibition of the observed effect of photolysed rose bengal was obtained with addition of histidine (25 mM), a singlet molecular oxygen quencher.

It was found that photolysis of rose bengal from a 1:2:2:1 quartet, characteristic of the hydroxyl radical‐DMPO spin adduct, which was effectively blunted by DMTU, superoxide dismutase and catalase whereas histidine was ineffective. The results of the electron spin resonance study also showed that a singlet molecular oxygen was produced by photoactivation of rose bengal; this was detected as singlet oxygen‐TEMP product (TEMPO; 2,2,6,6‐tetramethylpiperidine‐N‐oxyl). The formation of the TEMPO signal was strongly inhibited by histidine, but not by DMTU, superoxide dismutase and catalase.

It is suggested that the superoxide anion radical, H2O2 and hydroxyl radical are formed in addition to singlet molecular oxygen, and the data obtained from the present study indicate that singlet molecular oxygen is one of the most destructive oxygen species. Endothelium‐dependent relaxation is quite vulnerable to singlet molecular oxygen. Singlet oxygen also depresses noradrenaline‐induced contraction possibly via α‐adrenoceptor dysfunction. This, in turn, may lead to vascular incompetence.

British Journal of Pharmacology (1997) 121, 63–70; doi:10.1038/sj.bjp.0701103
Measurement of GABAA receptor function in rat cultured cerebellar granule cells by the Cytosensor microphysiometer
Authors: Brown Maria J , Wood Martyn D , Coldwell Martyn C , Bristow David R
Published: August 2006

γ‐Aminobutyric acid (GABA), acting via the GABAA receptor, increased the extracellular acidification rate of rat primary cultured cerebellar granule cells, measured by the Cytosensor microphysiometer.

The optimal conditions for the measurement of GABAA receptor function in cerebellar granule cells by microphysiometry were: cells seeded at 9–12×105 cells/transwell cup and maintained in vitro for 8 days, GABA stimulation performed at 25°C, with a stimulation time of 33 s.

GABA stimulated a concentration‐dependent increase in the extracellular acidification rate with an EC50 of 2.0±0.2 μM (mean±s.e.mean, n=7 experiments) and maximal increase (Emax) over basal response of 15.4±1.2%.

The sub‐maximal GABA‐stimulated increase in acidification rate could be potentiated by the 1,4‐benzodiazepine, flunitrazepam (100 nM). The 10 nM GABA response showed the maximal benzodiazepine facilitation (GABA alone, 1.4 μV s−1, GABA+flunitrazepam, 3.8 μV s−1, mean increment over basal, n=7).

The GABA‐stimulated increase in acidification rate was inhibited by the GABAA antagonist, bicuculline (100 μM) (90% inhibition at 1 mM GABA).

The results of this study show that activation of GABAA receptors in rat cerebellar granule cells caused an increase in the extracellular acidification rate; an effect which was potentiated by benzodiazepines and inhibited by a GABAA receptor antagonist. This paper defines the conditions and confirms the feasibility of using microphysiometry to investigate GABAA receptor function in primary cultured CNS neurones. The microphysiometer provides a rapid and sensitive technique to investigate the regulation of the GABAA receptor in populations of neurones.

British Journal of Pharmacology (1997) 121, 71–76; doi:10.1038/sj.bjp.0701106
Structure–function analysis of the U2 snRNP-associated splicing factor SF3a
Authors: Krämer A. , Ferfoglia F. , Huang C.-J. , Mulhaupt F. , Nesic D. , Tanackovic G.
Published: August 2006

Human splicing factor SF3a is a part of the 17 S U2 snRNP (small nuclear ribonucleoprotein), which interacts with the pre-mRNA branch site early during spliceosome formation. The SF3a subunits of 60, 66 and 120 kDa are all required for SF3a function in vitro. Depletion of individual subunits from HeLa cells by RNA interference results in a global inhibition of splicing, indicating that SF3a is a constitutive splicing factor. Structure–function analyses have defined domains necessary for interactions within the SF3a heterotrimer, association with the U2 snRNP and spliceosome assembly. Studies aimed at the identification of regions in SF3a60 and SF3a66, required for proper intracellular localization, have led to a model for the final steps in U2 snRNP biogenesis and the proposal that SF3a is incorporated into the U2 snRNP in Cajal bodies.
Multiple roles of arginine/serine-rich splicing factors in RNA processing
Authors: Sanford J.R. , Ellis J. , Cáceres J.F.
Published: August 2006

SR proteins (serine- and arginine-rich proteins) are an evolutionarily conserved family consisting of essential pre-mRNA splicing factors. Since their discovery and initial characterization, roles of SR proteins in pre-mRNA splicing and in subsequent steps of post-transcriptional gene expression have expanded significantly. The current hypotheses suggest that SR proteins are multifunctional adaptor molecules that may couple distinct steps of RNA metabolism. In the present study, we will provide an overview of the roles of SR proteins in different steps of post-transcriptional gene expression.
Regulation of alternative splicing by PTB and associated factors
Authors: Spellman R. , Rideau A. , Matlin A. , Gooding C. , Robinson F. , McGlincy N. , Grellscheid S.N. , Southby J. , Wollerton M. , Smith C.W.J.
Published: August 2006

PTB (polypyrimidine tract-binding protein) is a repressive regulator of alternative splicing. We have investigated the role of PTB in three model alternative splicing systems. In the α-actinin gene, PTB represses the SM (smooth muscle) exon by binding to key sites in the polypyrimidine tract. Repressive binding to these sites is assisted by co-operative binding to additional downstream sites. SM exon splicing can be activated by CELF proteins, which also bind co-operatively to interspersed sites and displace PTB from the pyrimidine tract. Exon 11 of PTB pre-mRNA is repressed by PTB in an autoregulatory feedback loop. Exon 11-skipped RNA gets degraded through nonsense-mediated decay. Less than 1% of steady-state PTB mRNA is represented by this isoform, but inhibition of nonsense-mediated decay by RNA interference against Upf1 shows that at least 20% of PTB RNA is consumed by this pathway. This represents a widespread but under-appreciated role of alternative splicing in the quantitative regulation of gene expression, an important addition to its role as a generator of protein isoform diversity. Repression of α-tropomyosin exon 3 is an exceptional example of PTB regulation, because repression only occurs at high levels in SM cells, despite the fact that PTB is widely expressed. In this case, a PTB-interacting cofactor, raver1, appears to play an important role. By the use of ‘tethering’ assays, we have identified discrete domains within both PTB and raver1 that mediate their repressive activities on this splicing event.
Folding and catalysis of the hairpin ribozyme
Authors: Wilson T.J. , Nahas M. , Ha T. , Lilley D.M.J.
Published: August 2006

The active form of the hairpin ribozyme is brought about by the interaction of two formally unpaired loops. In a natural molecule, these are present on two adjacent arms of a four-way junction. Although activity can be obtained in molecules lacking this junction, the junction is important in the promotion of the folded state of the ribozyme under physiological conditions, at a rate that is faster than the chemical reaction. Single-molecule fluorescence resonance energy transfer studies show that the junction introduces a discrete intermediate into the folding process, which repeatedly juxtaposes the two loops and thus promotes their docking. Using single-molecule enzymology, the cleavage and ligation rates have been measured directly. The pH dependence of the rates is consistent with a role for nucleobases acting in general acid–base catalysis.
RNA backbone rotamers – finding your way in seven dimensions
Authors: Murray L.J.W. , Richardson J.S. , Arendall W.B. , Richardson D.C.
Published: August 2006

Despite the importance of local structural detail for a mechanistic understanding of RNA catalysis and binding functions, RNA backbone conformation has been recalcitrant to analysis. There are too many variable dihedral angles per residue, and their raw empirical distributions are poorly clustered. This study applies quality-filtering techniques (using resolution, crystallographic B factor and all-atom-steric clashes) to the backbone dihedral angle distributions from a selected 8636 residue RNA database. With noise levels significantly decreased, clear signal appears for the underlying angle preferences. We analyse the multidimensional backbone dihedral distributions within sugar-to-sugar ‘suites’ rather than chemical residues due to the greater base interaction and steric interdependence within the suite. The final result is a small library of RNA backbone rotamers, each represented by a data cluster in seven-dimensional dihedral space, which should provide valid conformations for nearly all RNA backbones encountered in experimental structures. We are in the process of improving that library, and developing tools and applications for it in structure determination and analysis.
Ribosome crystallography: catalysis and evolution of peptide-bond formation, nascent chain elongation and its co-translational folding
Authors: Bashan A. , Yonath A.
Published: August 2006

A ribosome is a ribozyme polymerizing amino acids, exploiting positional- and substrate-mediated chemical catalysis. We showed that peptide-bond formation is facilitated by the ribosomal architectural frame, provided by a sizable symmetry-related region in and around the peptidyl transferase centre, suggesting that the ribosomal active site was evolved by gene fusion. Mobility in tunnel components is exploited for elongation arrest as well as for trafficking nascent proteins into the folding space bordered by the bacterial chaperone, namely the trigger factor.
Systems biology may work when we learn to understand the parts in terms of the whole
Authors: Cornish-Bowden A. , Cárdenas M.L.
Published: August 2006

The first point to note about whether systems biology will work is that the essential idea of systems biology is not new: there has been interest in it, as well as efforts to apply it, since the middle of the 20th century. The difference now is that it has become fashionable, with an explosion in the number of publications using the two words, albeit not always with the same meaning. The reductionist approach remains dominant, however, and systems biology is often seen as no more than integration of diverse data into models of systems. This way of thinking needs to be changed if systems biology is to lead to an understanding of life and to provide the benefits that are expected from it. The emphasis ought to be on the needs of the system as a whole for understanding the components, not the converse. General properties of metabolic systems, such as feed-back inhibition, can be properly understood by taking account of supply and demand, i.e. the requirements of the system as a whole, but this is often overlooked. Metabolism tends to be viewed as static, although enzymes (and proteins in general) are continuously synthesized and degraded. The fact that they are themselves therefore metabolites introduces great complexity to metabolism, including an implication of infinite regress; understanding how living organisms escape from this will be an essential step towards understanding life.
Algorithms for protein interaction networks
Authors: Lappe M. , Holm L.
Published: August 2006

The functional characterization of all genes and their gene products is the main challenge of the postgenomic era. Recent experimental and computational techniques have enabled the study of interactions among all proteins on a large scale. In this paper, approaches will be presented to exploit interaction information for the inference of protein structure, function, signalling pathways and ultimately entire interactomes. Interaction networks can be modelled as graphs, showing the operation of gene function in terms of protein interactions. Since the architecture of biological networks differs distinctly from random networks, these functional maps contain a signal that can be used for predictive purposes. Protein function and structure can be predicted by matching interaction patterns, without the requirement of sequence similarity. Moving on to a higher level definition of protein function, the question arises how to decompose complex networks into meaningful subsets. An algorithm will be demonstrated, which extracts whole signal-transduction pathways from noisy graphs derived from text-mining the biological literature. Finally, an algorithmic strategy is formulated that enables the proteomics community to build a reliable scaffold of the interactome in a fraction of the time compared with uncoordinated efforts.
Severe acute respiratory syndrome coronavirus nsp1 protein suppresses host gene expression by promoting host mRNA degradation
Authors: Kamitani Wataru , Narayanan Krishna , Huang Cheng , Lokugamage Kumari , Ikegami Tetsuro , Ito Naoto , Kubo Hideyuki , Makino Shinji
Published: August 2006

Severe acute respiratory syndrome (SARS) coronavirus (SCoV) causes a recently emerged human disease associated with pneumonia. The 5′ end two-thirds of the single-stranded positive-sense viral genomic RNA, gene 1, encodes 16 mature proteins. Expression of nsp1, the most N-terminal gene 1 protein, prevented Sendai virus-induced endogenous IFN-β mRNA accumulation without inhibiting dimerization of IFN regulatory factor 3, a protein that is essential for activation of the IFN-β promoter. Furthermore, nsp1 expression promoted degradation of expressed RNA transcripts and host endogenous mRNAs, leading to a strong host protein synthesis inhibition. SCoV replication also promoted degradation of expressed RNA transcripts and host mRNAs, suggesting that nsp1 exerted its mRNA destabilization function in infected cells. In contrast to nsp1-induced mRNA destablization, no degradation of the 28S and 18S rRNAs occurred in either nsp1-expressing cells or SCoV-infected cells. These data suggested that, in infected cells, nsp1 promotes host mRNA degradation and thereby suppresses host gene expression, including proteins involved in host innate immune functions. SCoV nsp1-mediated promotion of host mRNA degradation may play an important role in SCoV pathogenesis.
Joining the War: Masculinity, Nationalism and War Participation in the Balkans War of Secession, 1991–1995*
Authors: Milićević Aleksandra Sasha
Published: August 2006

Why do people go to war? My own interest in this question emerged from the context of my dissolving country and Serbia's increased engagement in a very strident form of ethnonationalism. Although social scientists have sought to understand the roles of ethnonationalism in fostering state-organized violence, few scholars have sought to understand the gendered nature of men's motivations for participating in war. The case of the inter-ethnic wars in Croatia and Bosnia, following the break-up of Yugoslavia, presents an unparalleled opportunity to understand more about how the processes of ethnonationalization and masculinization operate in everyday life, and about how men from Serbia made sense of their decisions about participation in the wars. In the present paper I explore the ways nationalism and masculinity intersect and overlap, influence and are influenced by war participation, by looking closer into the war volunteers from Serbia who joined the Yugoslav wars of secession, 1991–1995.
Basis properties of eigenfunctions of the 𝑝-Laplacian
Authors: Binding Paul , Boulton Lyonell , Čepička Jan , Drábek Pavel , Girg Petr
Published: August 2006

For

p
⩾

12
11

p\geqslant \frac {12}{11}

, the eigenfunctions of the non-linear eigenvalue problem for the

p
p

-Laplacian on the interval

(
0
,
1
)

(0,1)

are shown to form a Riesz basis of

L
2

(
0
,
1
)

L_2(0,1)

and a Schauder basis of

L
q

(
0
,
1
)

L_q(0,1)

whenever

1
>
q
>
∞

1>q>\infty

.
The Kodaira dimension of diffeomorphic Kähler threefolds
Authors: Răsdeaconu Rareş
Published: August 2006

We provide infinitely many examples of pairs of diffeomorphic, non-simply-connected Kähler manifolds of complex dimension three with different Kodaira dimensions. Also, in any possible Kodaira dimension we find infinitely many pairs of non-deformation equivalent, diffeomorphic Kähler threefolds.
The maximum principle for the Bergman space and the Möbius pseudodistance for the annulus
Authors: Schuster Alexander
Published: August 2006

It is shown that the formula for the Möbius pseudodistance for the annulus yields better estimates than previously known for the constant in the Bergman space maximum principle.
Symmetric modular Diophantine inequalities
Authors: Rosales J.
Published: August 2006

In this paper we study and characterize those Diophantine inequalities

a
x
mod
⁡
b
≤
x

ax\operatorname {mod} b\leq x

whose set of solutions is a symmetric numerical semigroup.
The 𝑃-Laplace equation on a class of Grushin-type spaces
Authors: Bieske Thomas , Gong Jasun
Published: August 2006

We find the fundamental solution to the

P
P

-Laplace equation in Grushin-type spaces. The singularity occurs at the sub-Riemannian points, which naturally corresponds to finding the fundamental solution of a generalized Grushin operator in Euclidean space. We then use this solution to find an infinite harmonic function with specific boundary data and to compute the capacity of annuli centered at the singularity. A solution to the 2-Laplace equation in a wider class of spaces is presented.
On the density of Banach spaces 𝐶(𝐾) with the Grothendieck property
Authors: Brech Christina
Published: August 2006

Using the method of forcing we prove that consistently there is a Banach space of continuous functions on a compact Hausdorff space with the Grothendieck property and with density less than the continuum. It follows that the classical result stating that “no nontrivial complemented subspace of a Grothendieck spaceC(K)C(K)is separable” cannot be strengthened by replacing “is separable” by “has density less than that ofl∞l_\infty”, without using an additional set-theoretic assumption. Such a strengthening was proved by Haydon, Levy and Odell, assuming Martin’s axiom and the negation of the continuum hypothesis. Moreover, our example shows that certain separation properties of Boolean algebras are quite far from the Grothendieck property.
Equivalence of domains arising from duality of orbits on flag manifolds II
Authors: Matsuki Toshihiko
Published: August 2006

S. Gindikin and the author defined a

G

R

G_{\mathbb {R}}

-

K

C

K_{\mathbb {C}}

invariant subset

C
(
S
)

C(S)

of

G

C

G_{\mathbb {C}}

for each

K

C

K_{\mathbb {C}}

-orbit

S
S

on every flag manifold

G

C

/

P

G_{\mathbb {C}}/P

and conjectured that the connected component

C
(
S

)
0

C(S)_0

of the identity would be equal to the Akhiezer-Gindikin domain

D
D

if

S
S

is of nonholomorphic type. This conjecture was proved for closed

S
S

in the works of J. A. Wolf, R. Zierau, G. Fels, A. Huckleberry and the author. It was also proved for open

S
S

by the author. In this paper, we prove the conjecture for all the other orbits when

G

R

G_{\mathbb {R}}

is of non-Hermitian type.
Morava 𝐾-theory rings for the dihedral, semidihedral and generalized quaternion groups in Chern classes
Authors: Bakuradze Malkhaz , Vershinin Vladimir
Published: August 2006

Morava

K
K

-theory rings of classifying spaces of the dihedral, semidihedral and generalized quaternion groups are presented in terms of Chern classes.
On Burch’s inequality and a reduction system of a filtration
Authors: Kinoshita Y. , Nishida K. , Yamanaka Y. , Yoneda A.
Published: August 2006

Let

F

=
{

F
n

}

\mathcal {F} = \{ F_n \}

be a multiplicative filtration of a local ring such that the Rees algebra

R

(

F

)

\mathrm {R}(\mathcal {F})

is Noetherian. We recall Burch’s inequality for

F

\mathcal {F}

and give an upper bound of the a-invariant of the associated graded ring

a

(

G

(

F

)
)

\mathrm {a}(\mathrm {G}(\mathcal {F}))

using a reduction system of

F

\mathcal {F}

. Applying those results, we study the symbolic Rees algebra of certain ideals of dimension

2
2

.
Sharp Gaussian bounds and 𝐿^{𝑝}-growth of semigroups associated with elliptic and Schrödinger operators
Authors: Ouhabaz El Maati
Published: August 2006

We prove sharp large time Gaussian estimates for heat kernels of elliptic and Schrödinger operators, including Schrödinger operators with magnetic fields. Our estimates are then used to prove that for general (magnetic) Schrödinger operators
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper A equals minus sigma-summation Underscript k equals 1 Overscript d Endscripts left-parenthesis StartFraction partial-differential Over partial-differential x Subscript k Baseline EndFraction minus i b Subscript k Baseline right-parenthesis squared plus upper V">

A
=
−

∑

k
=
1

d

(

∂

∂

x
k

−
i

b
k

)
2

+
V

A=-\sum _{k = 1}^d (\tfrac {\partial }{\partial x_k}-i b_k)^2 + V

, we have the

L
∞

L^\infty

-estimate (for large

t
t

):
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-vertical-bar e Superscript minus t upper A Baseline double-vertical-bar Subscript script upper L left-parenthesis upper L Sub Superscript normal infinity Subscript left-parenthesis double-struck upper R Sub Superscript d Subscript right-parenthesis right-parenthesis Baseline less-than-or-equal-to upper C e Superscript minus s left-parenthesis upper A right-parenthesis t Baseline left-parenthesis t ln t right-parenthesis Superscript d slash 4">

‖

e

−
t
A

‖

L

(

L
∞

(

R

d

)
)

≤
C

e

−
s
(
A
)
t

(
t
ln
⁡
t

)

d

/

4

\Vert e^{-tA} \Vert _{{\mathcal L}(L^\infty (\mathbb {R}^d))} \le C e^{-s(A)t} ( t\ln t)^{d/4}

\]
where

s
(
A
)
:=
inf
σ
(
A
)

s(A) := \inf \sigma (A)

is the spectral bound of

A
.

A.

The same estimate holds for elliptic and Schrödinger operators on general domains.
A short proof of an inequality of Littlewood and Paley
Authors: Pavlović Miroslav
Published: August 2006

A very short proof is given of the inequality
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="integral Underscript StartAbsoluteValue z EndAbsoluteValue greater-than 1 Endscripts StartAbsoluteValue nabla u left-parenthesis z right-parenthesis EndAbsoluteValue Superscript p Baseline left-parenthesis 1 minus StartAbsoluteValue z EndAbsoluteValue right-parenthesis Superscript p minus 1 Baseline d x d y less-than-or-equal-to upper C Subscript p Baseline left-parenthesis StartFraction 1 Over 2 pi EndFraction integral Subscript 0 Superscript 2 pi Baseline StartAbsoluteValue f left-parenthesis e Superscript i t Baseline right-parenthesis EndAbsoluteValue Superscript p Baseline d t minus StartAbsoluteValue u left-parenthesis 0 right-parenthesis EndAbsoluteValue Superscript p Baseline right-parenthesis comma">

∫

|

z

|

>
1

|

∇
u
(
z
)

|

p

(
1
−

|

z

|

)

p
−
1

d
x
d
y

≤

C
p

(

1

2
π

∫
0

2
π

|

f
(

e

i
t

)

|

p

d
t
−

|

u
(
0
)

|

p

)

,

\begin{equation*} \int _{|z|>1}|\nabla u(z)|^p (1-|z|)^{p-1}\, dxdy \, \le C_p\left (\frac 1{2\pi }\int _0^{2\pi } |f(e^{it})|^p\,dt -|u(0)|^p\right ), \end{equation*}

where

p
>
2
,

p>2,

and

u
u

is the Poisson integral of

f
∈

L
p

(
∂

D

)
,

f\in L^p(\partial \mathbb D),

D

=
{
z
:

|

z

|

>
1
}
.

\mathbb D=\{z: |z|>1\}.
A simple proof of Zagier duality for Hilbert modular forms
Authors: Choi D.
Published: August 2006

In this paper, we give a simple proof of an identity between the Fourier coefficients of the weakly holomorphic modular forms of weight

0
0

arising from Borcherds products of Hilbert modular forms and those of the weakly holomorphic modular forms of weight

2
2

satisfying a certain property.
Fixed points of univalent functions II
Authors: Schmieder Gerald
Published: August 2006

For a closed nowhere dense subset

C
C

of

∂

D

\partial \mathbb {D}

a bounded univalent holomorphic function

f
f

on

D

\mathbb {D}

is found such that

C
C

equals the cluster set of its fixed points.
An Itô formula for a fractional Brownian sheet with arbitrary Hurst parameters
Authors: Kim Yoon , Jeon Jong Woo
Published: August 2006

By using the white noise theory for a fractional Brownian sheet, we derive an Itô formula for the fractional Brownian sheet with arbitrary Hurst parameters

H

1

,

H

2

∈
(
0
,
1
)

H_{1}, H_{2}\in (0,1)

.
Toeplitz operators on Bloch-type spaces
Authors: Wu Zhijian , Zhao Ruhan , Zorboska Nina
Published: August 2006

We characterize complex measures

μ
\mu

on the unit disk for which the Toeplitz operator

T

μ

α

,

T_{\mu }^{\alpha },

α
>
0

\alpha >0

, is bounded or compact on the Bloch type spaces

B

α

B^{\alpha }

.
On the poles of topological zeta functions
Authors: Lemahieu Ann , Segers Dirk , Veys Willem
Published: August 2006

We study the topological zeta function

Z

t
o
p
,
f

(
s
)

Z_{top,f}(s)

associated to a polynomial

f
f

with complex coefficients. This is a rational function in one variable, and we want to determine the numbers that can occur as a pole of some topological zeta function; by definition these poles are negative rational numbers. We deal with this question in any dimension. Denote
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="script upper P Subscript n Baseline colon equals left-brace s 0 bar there-exists f element-of double-struck upper C left-bracket x 1 comma ellipsis comma x Subscript n Baseline right-bracket colon upper Z Subscript t o p comma f Baseline left-parenthesis s right-parenthesis">

P

n

:=
{

s
0

∣
∃
f
∈

C

[

x
1

,
…
,

x
n

]

:

Z

t
o
p
,
f

(
s
)

\mathcal {P}_n := \{ s_0 \mid \exists f \in \mathbb {C}[x_1,\ldots , x_n] \, : \, Z_{top,f}(s)

has a pole in

s
0

}

s_0 \}

. We show that

{
−
(
n
−
1
)

/

2
−
1

/

i
∣
i
∈

Z

>
1

}

\{-(n-1)/2-1/i \mid i \in \mathbb {Z}_{>1}\}

is a subset of

P

n

\mathcal {P}_n

; for

n
=
2

n=2

and

n
=
3

n=3

, the last two authors proved before that these are exactly the poles less than

−
(
n
−
1
)

/

2

-(n-1)/2

. As the main result we prove that each rational number in the interval

[
−
(
n
−
1
)

/

2
,
0
)

[-(n-1)/2,0)

is contained in

P

n

\mathcal {P}_n

.
Resolutions of ideals of fat points with support in a hyperplane
Authors: Fatabbi Giuliana , Harbourne Brian , Lorenzini Anna
Published: August 2006

Let

Z
′

Z’

be a fat point subscheme of

P

d

\mathbb {P}^{d}

, and let

x
0

x_0

be a linear form such that some power of

x
0

x_0

vanishes on

Z
′

Z’

(i.e., the support of

Z
′

Z’

lies in the hyperplane

H
H

defined by

x
0

=
0

x_0=0

, regarded as

P

d
−
1

\mathbb {P}^{d-1}

). Let

Z
(
i
)
=
H
∩

Z
′

(
i
)

Z(i)=H\cap Z’(i)

, where

Z
′

(
i
)

Z’(i)

is the subscheme of

P

d

\mathbb {P}^{d}

residual to

x
0
i

x_0^i

; note that

Z
(
i
)

Z(i)

is a fat points subscheme of

P

d
−
1

=
H

\mathbb {P}^{d-1}=H

. In this paper we give a graded free resolution of the ideal

I
(

Z
′

)

I(Z’)

over

R
′

=
K
[

P

d

]

R’=K[{\mathbb {P}}^{d}]

, in terms of the graded minimal free resolutions of the ideals

I
(
Z
(
i
)
)
⊂
R
=
K
[

P

d
−
1

]

I(Z(i))\subset R=K[{\mathbb {P}}^{d-1}]

. We also give a criterion for when the resolution is minimal, and we show that this criterion always holds if

char
⁡
(
K
)
=
0

\operatorname {char}(K)=0

.
A counterexample related to topological sums
Authors: Yamamoto Shuji , Yamashita Atsushi
Published: August 2006

In this paper we construct compact metric spaces

X
X

,

Y
Y

which are topologically distinct but whose topological sums

X
⊔
X

X \sqcup X

and

Y
⊔
Y

Y\sqcup Y

are homeomorphic.
A variational method in fixed point results with inwardness conditions
Authors: Azé D. , Corvellec J.-N.
Published: August 2006

We generalize, in a metric space setting, the result due to Lim (2000), that a weakly inward multivalued contraction, defined on a nonempty closed subset of a Banach space, has a fixed point. The simple proof of this generalization, avoiding the use of a transfinite induction as in Lim’s paper, is based on Ekeland’s variational principle (1974), along the lines of Hamel (1994) and Takahashi (1991). Moreover, we give a sharp estimate for the distance from any point to the fixed point set.
A posteriori FE error control for p-Laplacian by gradient recovery in quasi-norm
Authors: Carstensen Carsten , Liu W. , Yan N.
Published: August 2006

A posteriori error estimators based on quasi-norm gradient recovery are established for the finite element approximation of the p-Laplacian on unstructured meshes. The new a posteriori error estimators provide both upper and lower bounds in the quasi-norm for the discretization error. The main tools for the proofs of reliability are approximation error estimates for a local approximation operator in the quasi-norm.
Wavelets with patchwise cancellation properties
Authors: Harbrecht Helmut , Stevenson Rob
Published: August 2006

We construct wavelets on general

n
n

-dimensional domains or manifolds via a domain decomposition technique, resulting in so-called composite wavelets. With this construction, wavelets with supports that extend to more than one patch are only continuous over the patch interfaces. Normally, this limited smoothness restricts the possibility for matrix compression, and with that the application of these wavelets in (adaptive) methods for solving operator equations. By modifying the scaling functions on the interval, and with that on the

n
n

-cube that serves as parameter domain, we obtain composite wavelets that have patchwise cancellation properties of any required order, meaning that the restriction of any wavelet to each patch is again a wavelet. This is also true when the wavelets are required to satisfy zeroth order homogeneous Dirichlet boundary conditions on (part of) the boundary. As a result, compression estimates now depend only on the patchwise smoothness of the wavelets that one may choose. Also taking stability into account, our composite wavelets have all the properties for the application to the (adaptive) solution of well-posed operator equations of orders

2
t

2 t

for

t
∈
(
−

1
2

,

3
2

)

t \in (-\frac {1}{2},\frac {3}{2})

.
Rate of convergence of finite difference approximations for degenerate ordinary differential equations
Authors: Zhang Jianfeng
Published: August 2006

In this paper we study finite difference approximations for the following linear stationary convection-diffusion equations:
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="one half sigma squared left-parenthesis x right-parenthesis u left-parenthesis x right-parenthesis plus b left-parenthesis x right-parenthesis u prime left-parenthesis x right-parenthesis minus u left-parenthesis x right-parenthesis equals minus f left-parenthesis x right-parenthesis comma x element-of double-struck upper R comma">

1
2

σ
2

(
x
)
u
(
x
)
+
b
(
x
)

u
′

(
x
)
−
u
(
x
)
=
−
f
(
x
)
,

x
∈

R

,

{1\over 2}\sigma ^2(x)u(x) + b(x)u’(x) - u(x) =-f(x),\quad x\in \mathbb {R},

\]
where

σ
\sigma

is allowed to be degenerate. We first propose a new weighted finite difference scheme, motivated by approximating the diffusion process associated with the equation in the strong sense. We show that, under certain conditions, this scheme converges with the first order rate and that such a rate is sharp. To the best of our knowledge, this is the first sharp result in the literature. Moreover, by using the connection between our scheme and the standard upwind finite difference scheme, we get the rate of convergence of the latter, which is also new.
Fast computation of a rational point of a variety over a finite field
Authors: Cafure Antonio , Matera Guillermo
Published: August 2006

We exhibit a probabilistic algorithm which computes a rational point of an absolutely irreducible variety over a finite field defined by a reduced regular sequence. Its time-space complexity is roughly quadratic in the logarithm of the cardinality of the field and a geometric invariant of the input system. This invariant, called the degree, is bounded by the Bézout number of the system. Our algorithm works for fields of any characteristic, but requires the cardinality of the field to be greater than a quantity which is roughly the fourth power of the degree of the input variety.
Gene Targeting of Cdc42 and Cdc42GAP Affirms the Critical Involvement of Cdc42 in Filopodia Induction, Directed Migration, and Proliferation in Primary Mouse Embryonic Fibroblasts
Authors: Yang Linda , Wang Lei , Zheng Yi
Published: August 2006

Recent studies in Cdc42 knockout mouse embryonic stem (ES) cells and ES-derived fibroblastoid cell lines raise concern on a body of literature derived by dominant mutant expression approach in a variety of cell lines implicating mammalian Cdc42 as a key regulator of filopodia induction, directional migration and cell cycle progression. To resolve the physiological function of mammalian Cdc42, we have characterized the Cdc42−/− and Cdc42GAP−/− primary mouse embryonic fibroblasts (MEFs) produced by gene targeting as the Cdc42 loss- or gain-of-activity cell model. The Cdc42−/− cells were defective in filopodia formation stimulated by bradykinin and in dorsal membrane ruffling stimulated by PDGF, whereas the Cdc42GAP−/− cells displayed spontaneous filopodia. The Cdc42 loss- or gain-of-activity cells were defective in adhesion to fibronectin, wound-healing, polarity establishment, and migration toward a serum gradient. These defects were associated with deficiencies of PAK1, GSK3β, myosin light chain, and FAK phosphorylation. Furthermore, Cdc42−/− cells were defective in G1/S-phase transition and survival, correlating with deficient NF-κB transcription and defective JNK, p70 S6K, and ERK1/2 activation. These results demonstrate a different requirement of Cdc42 activity in primary MEFs from ES or ES-derived clonal fibroblastoid cells and suggest that Cdc42 plays cell-type–specific signaling roles.
Anaerobic bacteria in 118 patients with deep-space head and neck infections from the University Hospital of Maxillofacial Surgery, Sofia, Bulgaria
Authors: Boyanova Lyudmila , Kolarov Rossen , Gergova Galina , Deliverska Elitsa , Madjarov Jivko , Marinov Milen , Mitov Ivan
Published: August 2006

The aim of this study was to assess the incidence and susceptibility to antibacterial agents of anaerobic strains in 118 patients with head and neck abscesses (31) and cellulitis (87). Odontogenic infection was the most common identified source, occurring in 73 (77.7 %) of 94 patients. The incidence of anaerobes in abscesses and cellulitis was 71 and 75.9 %, respectively, and that in patients before (31 patients) and after (87) the start of empirical treatment was 80.6 and 72.4 %, respectively. The detection rates of anaerobes in patients with odontogenic and other sources of infection were 82.2 and 71.4 %, respectively. In total, 174 anaerobic strains were found. The predominant bacteria were Prevotella (49 strains), Fusobacterium species (22), Actinomyces spp. (21), anaerobic cocci (20) and Eubacterium spp. (18). Bacteroides fragilis strains were isolated from 7 (5.9 %) specimens. The detection rate of Fusobacterium strains from non-treated patients (32.2 %) was higher than that from treated patients (13.8 %). Resistance rates to clindamycin and metronidazole of Gram-negative anaerobes were 5.4 and 2.5 %, respectively, and those of Gram-positive species were 4.5 and 58.3 %, respectively. One Prevotella strain was intermediately susceptible to ampicillin/sulbactam. In conclusion, the start of empirical treatment could influence the frequency or rate of isolation of Fusobacterium species. The involvement of the Bacteroides fragilis group in some head and neck infections should be considered.
Typing of intimin (eae) genes from enteropathogenic Escherichia coli (EPEC) isolated from children with diarrhoea in Montevideo, Uruguay: identification of two novel intimin variants (μB and ξR/β2B)
Authors: Blanco Miguel , Blanco Jesús E. , Dahbi Ghizlane , Mora Azucena , Alonso María Pilar , Varela Gustavo , Gadea María Pilar , Schelotto Felipé , González Enrique A. , Blanco Jorge
Published: August 2006

A total of 71 enteropathogenic Escherichia coli (EPEC) strains isolated from children with diarrhoea in Montevideo, Uruguay, were characterized in this study. PCR showed that 57 isolates carried eae and bfp genes (typical EPEC strains), and 14 possessed only the eae gene (atypical EPEC strains). These EPEC strains belonged to 21 O : H serotypes, including eight novel serotypes not previously reported among human EPEC in other studies. However, 72 % belonged to only four serotypes: O55 : H− (six strains), O111 : H2 (13 strains), O111 : H− (14 strains) and O119 : H6 (18 strains). Nine intimin types, namely, α1 (two O142 strains), β1 (29 strains, including 13 O111 : H2 and 14 O111 : H−), γ1 (three O55 : H− strains), θ (five strains, including three strains with H40 antigen), κ (two strains), ε1 (one strain), λ (one strain), μB (six strains of serotypes O55 : H51 and O55 : H−) and ξR/β2B (22 strains, including 18 O119 : H6) were detected among the 71 EPEC strains. The authors have identified two novel intimin genes (μB and ξR/β2B) in typical EPEC strains of serotypes O55 : H51/H− and O119 : H6/H−. The complete nucleotide sequences of the novel μB and ξR/β2 variant genes were determined. PFGE typing after XbaI DNA digestion was performed on 44 representative EPEC strains. Genomic DNA fingerprinting revealed 44 distinct restriction patterns and the strains were clustered in 12 groups. Only 15 strains clustered in six groups of closely related (similarity >85 %) PFGE patterns, suggesting the prevailing clonal diversity among EPEC strains isolated from children with diarrhoea in Montevideo.
Detection of typical and atypical enteropathogenic Escherichia coli (EPEC) in Iranian children with and without diarrhoea
Authors: Alikhani M. Yousef , Mirsalehian Akbar , Aslani M. Mehdi
Published: August 2006

The present study was performed to investigate the contribution of typical and atypical enteropathogenic Escherichia coli (EPEC) as a cause of infectious diarrhoea among children less than 10 years old in Iran. During the summer months, 247 specimens from children with diarrhoea and 1108 from asymptomatic children were analysed for the presence of EPEC and other bacterial pathogens. Potential enteric pathogens were identified in 140 cases of children with diarrhoea (56.7 %). EPEC was the most frequently identified agent (111 cases), followed by Shiga toxin-producing E. coli (13), Shigella (9), Salmonella (6) and Aeromonas sp. (1). EPEC isolates were examined for the presence of eaeA, bfpA and stx genes by PCR. EPEC isolates were classified as typical (eaeA
+
bfpA
+) or atypical (eaeA
+
bfpA
−). Typical EPEC was diagnosed in 35 cases (11.8 %), compared with 8 (0.4 %) in the asymptomatic group (P<0.05). Atypical EPEC strains were isolated from 23 cases (9.3 %), compared with 13 (1.2 %) of the healthy control group (P<0.05). In conclusion, the data suggest that typical and atypical EPEC are an important cause of diarrhoea in Iranian children.
Inter-laboratory comparison of three different real-time PCR assays for the detection of Pneumocystis jiroveci in bronchoalveolar lavage fluid samples
Authors: Linssen Catharina F. M. , Jacobs Jan A. , Beckers Pieter , Templeton Kate E. , Bakkers Judith , Kuijper Ed J. , Melchers Willem J. G. , Drent Marjolein , Vink Cornelis
Published: August 2006

Pneumocystis jirovecipneumonia (PCP) is an opportunistic infection affecting immunocompromised patients. While conventional diagnosis of PCP by microscopy is cumbersome, the use of PCR to diagnose PCP has great potential. Nevertheless, inter-laboratory validation and standardization of PCR assays is lacking. The aim of this study was to evaluate the inter-laboratory agreement of three independently developed real-time PCR assays for the detection ofP. jiroveciin bronchoalveolar lavage fluid samples. Therefore, 124 samples were collected in three tertiary care laboratories (Leiden University Medical Center, Maastricht Infection Center and Radboud University Nijmegen Medical Centre) and were tested by both microscopy and real-time PCR. Of 41 samples positive forP. jiroveciby microscopy, 40 were positive in all three PCR assays. The remaining sample was positive in a single assay only. Out of 83 microscopy-negative samples, 69 were negative in all three PCR assays. The other 14 samples were found positive, either in all three assays (n=5), in two (n=2) or in one of the assays (n=7). The data demonstrate high inter-laboratory agreement among real-time PCR assays for the detection ofP. jiroveci.
Effect of antifungal treatment on the prevalence of yeasts in HIV-infected subjects
Authors: Patel Mrudula , Shackleton Joanne T. , Coogan Maeve M.
Published: August 2006

Oral candidiasis, the most common opportunistic infection in patients with HIV infection, is usually associated with Candida albicans. Several factors may influence the carriage of Candida, including immunocompromised conditions and HIV infection, colonization by yeasts from different geographical areas and antimycotic treatment. This study investigated the Candida carrier rate, level and types of yeast in HIV-positive and -negative subjects, and the effect of previous exposure to antifungal drugs on the level of yeasts in HIV-positive patients in Gauteng, South Africa. Unstimulated saliva was collected from 332 HIV-positive patients and 100 HIV-negative subjects and cultured for yeasts. The number and species of yeast were determined. HIV-positive patients who carried yeasts were divided into two groups depending upon their previous antifungal drug exposure, and the level of Candida carriage in each group was compared. The Candida carrier rate in the HIV-positive patients (81.3 %) was slightly higher than previously reported and significantly higher (P<0.001) than in the HIV-negative group (63 %). The carrier rate in the HIV-negative group was also higher than in earlier studies. Fourteen per cent of the HIV-positive patients carried more than 10 000 c.f.u. ml−1 whereas none of the HIV-negative subjects carried this large a number of yeasts (P<0.001). Seventy per cent of the yeasts were identified as C. albicans and approximately 30 % as non-albicans species. In conclusion, the Candida carrier rate is higher in the South African population than elsewhere. HIV-positive patients carry more and a greater variety of yeasts than HIV-negative subjects. Exposure to antifungal drugs has no effect on the level of yeast carriage in HIV-positive patients.
CTX-M-producing Salmonella spp. in Hong Kong: an emerging problem
Authors: Jin Yujuan , Ling J. M.
Published: August 2006

Two Salmonella enterica serovar Typhimurium isolates and one S. enterica serovar Enteritidis isolate that were resistant to 4 μg cefotaxime ml−1 and produced CTX-M-type extended-spectrum β-lactamases (ESBLs) were characterized from patients in Hong Kong during 2003–2004. The S. Typhimurium strain isolated in 2003 produced a CTX-M-9 ESBL and harboured a bla
CTX-M-9 gene that was associated with a class I integron-containing gene cassette and orf513 similar to those of In60. The second S. Typhimurium strain and the S. Enteritidis strain, both isolated in 2004, produced CTX-M-14; the former also produced TEM-1. The bla
CTX-M-14 gene in these two isolates was associated with the insertion sequence ISEcp1. The CTX-M genes were present on a transferable plasmid of 62, 70 or 92 kb. PFGE of XbaI-restricted total DNA from the two S. Typhimurium isolates indicated that they were not clonally related. These three isolates were also resistant to one of the other non-β-lactam antimicrobial agents tested. This is the first report of a CTX-M-9 ESBL in Salmonella in Hong Kong and the presence of bla
CTX-M-9 and bla
CTX-M-14 in S. Typhimurium.