bluuebunny/crossref_metadata_2025 huggingface dataset:
Euler characteristics, Akashi series and compact 𝑝-adic Lie groups
Authors: Wadsley Simon
Published: July 2010

We discuss Euler characteristics for finitely generated modules over Iwasawa algebras. We show that the Euler characteristic of a module is well-defined whenever the

0
0

th homology group is finite if and only if the relevant compact

p
p

-adic Lie group is finite-by-nilpotent and that in this case all pseudo-null modules have trivial Euler characteristic. We also prove some other results relating to the triviality of Euler characteristics for pseudo-null modules as well as some analogous results for the Akashi series of Coates et al.
Factoring newparts of Jacobians of certain modular curves
Authors: Murty M. , Sinha Kaneenika
Published: July 2010

We prove a conjecture of Yamauchi which states that the level

N
N

for which the new part of

J
0

(
N
)

J_0(N)

is

Q

\mathbb {Q}

-isogenous to a product of elliptic curves is bounded. We also state and partially prove a higher-dimensional analogue of Yamauchi’s conjecture. In order to prove the above results, we derive a formula for the trace of Hecke operators acting on spaces

S

n
e
w

(
N
,
k
)

S^{new}(N,k)

of newforms of weight

k
k

and level

N
.

N.

We use this trace formula to study the equidistribution of eigenvalues of Hecke operators on these spaces. For any

d
≥
1
,

d\geq 1,

we estimate the number of normalized newforms of fixed weight and level, whose Fourier coefficients generate a number field of degree less than or equal to

d
.

d.
On a result of Faltings via tight closure
Authors: Sharif Tirdad
Published: July 2010

Using a result in the theory of tight closure on

F
F

-rational rings, we prove a criterion for local rings of positive prime characteristic to be complete intersections. As an application of our criterion, we give a new and simple proof for an extension of an algebraic result of Faltings that was used by Taylor and Wiles for a simplification of the proof of the minimal deformation problem.
Dual of the function algebra 𝐴^{-∞}(𝐷) and representation of functions in Dirichlet series
Authors: Abanin A. , Khoi Le
Published: July 2010

In this paper we present the following results: a description, via the Laplace transformation of analytic functionals, of the dual to the (DFS)-spaceA−∞(D)A^{-\infty }(D)(DDbeing either a boundedC2C^2-smooth convex domain inCN\mathbb {C}^N, withN>1N>1, or a bounded convex domain inC\mathbb {C}) as an (FS)-spaceAD−∞A^{-\infty }_Dof entire functions satisfying a certain growth condition; an explicit construction of a countable sufficient set forAD−∞A^{-\infty }_D; and a possibility of representating functions fromA−∞(D)A^{-\infty }(D)in the form of Dirichlet series.
An optimization problem for the first weighted eigenvalue problem plus a potential
Authors: Del Pezzo Leandro , Bonder Julián
Published: July 2010

In this paper, we study the problem of minimizing the first eigenvalue of the

p
−

p-

Laplacian plus a potential with weights when the potential and the weight are allowed to vary in the class of rearrangements of a given fixed potential

V
0

V_0

and weight

g
0

g_0

. Our results generalize those obtained in earlier papers.
Motivic strict ring models for 𝐾-theory
Authors: Röndigs Oliver , Spitzweck Markus , Østvær Paul
Published: July 2010

It is shown that theKK-theory of every noetherian base scheme of finite Krull dimension is represented by a commutative strict ring object in the setting of motivic stable homotopy theory. The adjective ‘strict’ is used here in order to distinguish between the type of ring structure we construct and one which is valid only up to homotopy. An analogous topological result follows by running the same type of arguments as in the motivic setting.
A remark on nonlinear Dirac equations
Authors: Wang Changyou
Published: July 2010

For an

n
n

-dimensional spin manifold

M
M

with a fixed spin structure and a spinor bundle

Σ
M

\Sigma M

, we prove an

ϵ
\epsilon

-regularity theorem for weak solutions to the nonlinear Dirac equation
\[

∂̸
ψ
=

H

j
k
l

⟨

ψ
j

,

ψ
k

⟩

ψ
l

,

\not \partial \psi = H_{jkl}\langle \psi ^j, \psi ^k\rangle \psi ^l,

\]
of cubic nonlinearity. In particular, it implies that any weak solution is smooth when

n
=
2

n=2

, which answers a question raised by Chen, Jost, and Wang.
The corona problem with two pieces of data
Authors: Krantz Steven
Published: July 2010

We study the corona problem on the unit ball in

C

n

\mathbb {C}^n

, and more generally on strongly pseudoconvex domains in

C

n

\mathbb {C}^n

. When the corona problem has just two pieces of data, and an extra geometric hypothesis is satisfied, then we are able to solve it.
Entropy for 𝐶*-algebras with tracial rank zero
Authors: Okayasu Rui
Published: July 2010

Voiculescu’s topological approximation entropy is extended to automorphisms on unital simple

C
∗

C^*

-algebras with tracial rank zero. Several expected properties are shown. We also consider the value of our entropy for a cat map on the non-commutative torus.
The Gabriel-Roiter submodules of simple homogeneous modules
Authors: Chen Bo
Published: July 2010

Let

Λ
\Lambda

be a connected tame hereditary algebra over an algebraically closed field. We show that if

Λ
=
k
Q

\Lambda =kQ

is of type

A

~

n

\widetilde {\mathbb {A}}_n

,

D

~

n

\widetilde {\mathbb {D}}_n

,

E

~

6

\widetilde {\mathbb {E}}_6

or

E

~

7

\widetilde {\mathbb {E}}_7

, then every Gabriel-Roiter submodule of a quasi-simple module of rank

1
1

(i.e. a simple homogeneous module) has defect

−
1

-1

. In particular, any Gabriel-Roiter submodule of a simple homogeneous module yields a Kronecker pair, and thus induces a full exact embedding of the category

mod
⁡
k

A

~

1

\operatorname {mod} k\widetilde {\mathbb {A}}_1

into

mod
⁡
Λ

\operatorname {mod}\Lambda

, where

A

~

1

\widetilde {\mathbb {A}}_1

is the Kronecker quiver. Consequently, we obtain that all quasi-simple modules are Gabriel-Roiter factor modules.
On spectral gap rigidity and Connes invariant 𝜒(𝑀)
Authors: Popa Sorin
Published: July 2010

We calculate Connes’ invariantχ(M)\chi (M)for certain II1_{1}factorsMMthat can be obtained as inductive limits of subfactors with spectral gap. Then we use this to answer a question he posed in 1975 on the structure of McDuff factorsMMwithχ(M)=1\chi (M)=1.
Trace-positive complex polynomials in three unitaries
Authors: Popovych Stanislav
Published: July 2010

We consider the quadratic polynomials in three unitary generators, i.e. the elements of the group

∗
*

-algebra of the free group with generators

u
1

,

u
2

,

u
3

u_1, u_2, u_3

of the form

f
=

∑

j
,
k
=
1

3

α

j
k

u

j

∗

u

k

f=\sum _{j, k=1}^{3}\alpha _{jk}u_{j}^{*}u_{k}

,

α

j
k

∈

C

\alpha _{jk} \in \mathbb {C}

. We prove that if

f
f

is self-adjoint and

T
r

(
f
(

U

1

,

U
2

,

U

3

)
)
≥
0

\mathrm {Tr}(f(U_{1}, U_2 ,U_{3}))\ge 0

for arbitrary unitary matrices

U

1

,

U
2

,

U
3

U_{1}, U_2, U_3

, then

f
f

is a sum of hermitian squares. To prove this statement we reduce it to the question whether a certain Tarski sentence is true. Tarski’s decidability theorem thus provides an algorithm to answer this question. We use an algorithm due to Lazard and Rouillier for computing the number of real roots of a parametric system of polynomial equations and inequalities implemented in Maple to check that the Tarski sentence is true.

As an application, we describe the set of parameters

a
1

,

a
2

,

a
3

,

a
4

a_1, a_2, a_3, a_4

such that there are unitary operators

U
1

,
…
,

U
4

U_1, \ldots , U_4

connected by the linear relation

a
1

U
1

+

a
2

U
2

+

a
3

U
3

+

a
4

U
4

=
0

a_1 U_1+a_2 U_2 +a_3 U_3 +a_4 U_4 =0

.
An easier extra head scheme for the Poisson process on 𝐑ⁿ
Authors: Service Robert
Published: July 2010

A simple construction is presented whereby a nonrandomized extra head scheme for stationary ergodic point processes on the line due to T. Liggett (2002) is lifted to

R

n

\mathbf {R}^{n}

in the Poisson case. This gives the simplest construction for a nonrandomized extra head scheme in higher dimensions, yet the method has been overlooked in previous work on the subject.
An irreducibility criterion for group representations, with arithmetic applications
Authors: Longo Matteo , Vigni Stefano
Published: July 2010

We prove a criterion for the irreducibility of an integral group representation

ρ
\rho

over the fraction field of a Noetherian domain

R
R

in terms of suitably defined reductions of

ρ
\rho

at prime ideals of

R
R

. As applications, we give irreducibility results for universal deformations of residual representations, with special attention to universal deformations of residual Galois representations associated with modular forms of weight at least

2
2

.
A new approach to the expansion of positivity set of non-negative solutions to certain singular parabolic partial differential equations
Authors: DiBenedetto Emmanuele , Gianazza Ugo , Vespri Vincenzo
Published: July 2010

Let

u
u

be a non-negative solution to a singular parabolic equation of

p
p

-Laplacian type (

1
>
p
>
2

1>p>2

) or porous-medium type (

0
>
m
>
1

0>m>1

). If

u
u

is bounded below on a ball

B
ρ

B_\rho

by a positive number

M
M

, for times comparable to

ρ
\rho

and

M
M

, then it is bounded below by

σ
M

\sigma M

, for some

σ
∈
(
0
,
1
)

\sigma \in (0,1)

, on a larger ball, say

B

2
ρ

B_{2\rho }

, for comparable times. This fact, stated quantitatively in this paper, is referred to as the “spreading of positivity” of solutions of such singular equations and is at the heart of any form of Harnack inequality. The proof of such a “spreading of positivity” effect, first given in 1992, is rather involved and not intuitive. Here we give a new proof, which is more direct, being based on geometrical ideas.
A generalized Fernique theorem and applications
Authors: Friz Peter , Oberhauser Harald
Published: July 2010

We prove a generalisation of Fernique’s theorem which applies to a class of (measurable) functionals on abstract Wiener spaces by using the isoperimetric inequality. Our motivation comes from rough path theory where one deals with iterated integrals of Gaussian processes (which are generically not Gaussian). Gaussian integrability with explicitly given constants for variation and Hölder norms of the (fractional) Brownian rough path, Gaussian rough paths and the Banach space valued Wiener process enhanced with its Lévy area [Ledoux, Lyons, Qian. “Lévy area of Wiener processes in Banach spaces”, Ann. Probab., 30(2):546–578, 2002] then all follow from applying our main theorem.
ℎ𝑝-Optimal discontinuous Galerkin methods for linear elliptic problems
Authors: Stamm Benjamin , Wihler Thomas
Published: July 2010

The aim of this paper is to present and analyze a class ofhphp-version discontinuous Galerkin (DG) discretizations for the numerical approximation of linear elliptic problems. This class includes a number of well-known DG formulations. We will show that the methods are stable provided that the stability parameters are suitably chosen. Furthermore, on (possibly irregular) quadrilateral meshes, we shall prove that the schemes converge all optimally in the energy norm with respect to both the local element sizes and polynomial degrees provided that homogeneous boundary conditions are considered.
Discontinuous Galerkin approximations of the Stokes and Navier-Stokes equations
Authors: Chrysafinos Konstantinos , Walkington Noel
Published: July 2010

Numerical schemes to compute approximate solutions of the evolutionary Stokes and Navier-Stokes equations are studied. The schemes are discontinuous in time and conforming in space and of arbitrarily high order. Fully-discrete error estimates are derived and dependence of the viscosity constant is carefully tracked. It is shown that the errors are bounded by projection errors of the exact solution which exhibit optimal rates when the solutions are smooth.
A sharp region where 𝜋(𝑥)-𝑙𝑖(𝑥) is positive
Authors: Saouter Yannick , Demichel Patrick
Published: July 2010

In this article, we study the problem of changes of sign of

π
(
x
)
−

l
i

(
x
)

\pi (x)-{\mathrm {li}}(x)

. We provide three improvements. First, we give better esimates of error term for Lehman’s theorem. Second, we rigorously prove the positivity of this difference for a region formerly conjectured by Patrick Demichel. Third, we improve the estimates for regions of positivity by using number theoretic results.
On a class of frozen regularized Gauss-Newton methods for nonlinear inverse problems
Authors: Jin Qinian
Published: July 2010

In this paper we consider a class of regularized Gauss-Newton methods for solving nonlinear inverse problems for which an a posteriori stopping rule is proposed to terminate the iteration. Such methods have the frozen feature that they require only the computation of the Fréchet derivative at the initial approximation. Thus the computational work is considerably reduced. Under certain mild conditions, we give the convergence analysis and derive various estimates, including the order optimality, on these methods.
Approximation of the discontinuities of a function by its classical orthogonal polynomial Fourier coefficients
Authors: Kvernadze George
Published: July 2010

In the present paper, we generalize the method suggested in an earlier paper by the author and overcome its main deficiency.

First, we modify the well-known Prony method, which subsequently will be utilized for recovering exactly the locations of jump discontinuities and the associated jumps of a piecewise constant function by means of its Fourier coefficients with respect to any system of the classical orthogonal polynomials.

Next, we will show that the method is applicable to a wider class of functions, namely, to the class of piecewise smooth functions—for functions which piecewise belong to

C
2

[
−
1
,
1
]

C^2[-1,1]

, the locations of discontinuities are approximated to within

O
(
1

/

n
)

O(1/n)

by means of their Fourier-Jacobi coefficients. Unlike the previous one, the generalized method is robust, since its success is independent of whether or not a location of the discontinuity coincides with a root of a classical orthogonal polynomial. In addition, the error estimate is uniform for any

[
c
,
d
]
⊂
(
−
1
,
1
)

[c,d]\subset (-1,1)

.

To the end, we discuss the accuracy, stability, and complexity of the method and present numerical examples.
A multimodular algorithm for computing Bernoulli numbers
Authors: Harvey David
Published: July 2010

We describe an algorithm for computing Bernoulli numbers. Using a parallel implementation, we have computed

B
k

B_k

for

k
=

10
8

k = 10^8

, a new record. Our method is to compute

B
k

B_k

modulo

p
p

for many small primes

p
p

and then reconstruct

B
k

B_k

via the Chinese Remainder Theorem. The asymptotic time complexity is

O
(

k
2

log

2
+
ε

⁡
k
)

O(k^2 \log ^{2+\varepsilon } k)

, matching that of existing algorithms that exploit the relationship between

B
k

B_k

and the Riemann zeta function. Our implementation is significantly faster than several existing implementations of the zeta-function method.
Using partial smoothness of 𝑝-1 for factoring polynomials modulo 𝑝
Authors: Źrałek Bartosz
Published: July 2010

Let an arbitrarily small positive constant

δ
\delta

less than

1
1

and a polynomial

f
f

with integer coefficients be fixed. We prove unconditionally that

f
f

modulo

p
p

can be completely factored in deterministic polynomial time if

p
−
1

p-1

has a

(
ln
⁡
p

)

O
(
1
)

(\ln p)^{O(1)}

-smooth divisor exceeding

p
δ

p^\delta

. We also address the issue of factoring

f
f

modulo

p
p

over finite extensions of the prime field

F

p

\mathbb {F}_p

and show that

p
−
1

p-1

can be replaced by

p
k

−
1

p^k-1

(

k
∈

N

k\in \mathbb {N}

) for explicit classes of primes

p
p

.
Multigrid in a weighted space arising from axisymmetric electromagnetics
Authors: Copeland Dylan , Gopalakrishnan Jayadeep , Oh Minah
Published: July 2010

Consider the space of two-dimensional vector functions whose components and curl are square integrable with respect to the degenerate weight given by the radial variable. This space arises naturally when modeling electromagnetic problems under axial symmetry and performing a dimension reduction via cylindrical coordinates. We prove that if the original three-dimensional domain is convex, then the multigrid V-cycle applied to the inner product in this space converges, provided certain modern smoothers are used. For the convergence analysis, we first prove several intermediate results, e.g., the approximation properties of a commuting projector in weighted norms, and a superconvergence estimate for a dual mixed method in weighted spaces. The uniformity of the multigrid convergence rate with respect to mesh size is then established theoretically and illustrated through numerical experiments.
Smooth analysis of the condition number and the least singular value
Authors: Tao Terence , Vu Van
Published: July 2010

Let

x
x

be a complex random variable with mean zero and bounded variance. Let

N

n

N_{n}

be the random matrix of size

n
n

whose entries are iid copies of

x
x

and let

M
M

be a fixed matrix of the same size. The goal of this paper is to give a general estimate for the condition number and least singular value of the matrix

M
+

N

n

M + N_{n}

, generalizing an earlier result of Spielman and Teng for the case when

x
x

is gaussian.

Our investigation reveals an interesting fact that the “core” matrix

M
M

does play a role on tail bounds for the least singular value of

M
+

N

n

M+N_{n}

. This does not occur in Spielman-Teng studies when

x

{x}

is gaussian. Consequently, our general estimate involves the norm

‖
M
‖

\|M\|

. In the special case when

‖
M
‖

\|M\|

is relatively small, this estimate is nearly optimal and extends or refines existing results.
REVIEW: Variability in Fine Structures of Noncellulosic Cell Wall Polysaccharides from Cereal Grains: Potential Importance in Human Health and Nutrition
Authors: Collins Helen M. , Burton Rachel A. , Topping David L. , Liao Ming‐Long , Bacic Antony , Fincher Geoffrey B.
Published: July 2010

Noncellulosic polysaccharides from the cell walls of cereal grains are not digested by human small intestinal enzymes and so contribute to total dietary fiber intake. These polysaccharides are becoming recognized increasingly for their potential to lower the risk of serious diet‐related conditions such as type II diabetes, cardiovascular disease, colorectal cancer, and diverticular disease. The effectiveness of noncellulosic cell wall polysaccharides in improving health outcomes is related to the fine structure and associated physicochemical properties. The two most nutritionally relevant wall polysaccharides of cereal grains are the arabinoxylans and the (1‐3,1‐4)‐β‐d‐glucans. These polysaccharides have high molecular mass values but are nevertheless soluble in aqueous media, at least in part, where they adopt highly asymmetrical conformations and consequently form high viscosity solutions. Thus, arabinoxylans and (1‐3,1‐4)‐β‐d‐glucans contribute to the soluble fiber component of human diets. The molecular size, solubility, and viscosity of the polysaccharides vary widely not only between different cereals but also within a single species. The variability in these properties reflects differences in the chemical structure of the polysaccharides, which in turn influences the beneficial effects of arabinoxylans and (1‐3,1‐4)‐β‐d‐glucans in human diets. Here, we summarize information on the variability of fine structures of the arabinoxylans and (1‐3,1‐4)‐β‐d‐glucans in common cereals and relate these to solubility, viscosity, and health benefits. The recent identification of genes involved in the biosynthesis of the (1‐3,1‐4)‐β‐d‐glucans opens the way for the genetic improvement of cereal quality parameters that are important in human health.
Programmed cell death 4 enhances chemosensitivity of ovarian cancer cells by activating death receptor pathway in vitro and in vivo
Authors: Zhang Xia , Wang Xiaoyan , Song Xingguo , Liu Chunmei , Shi Yongyu , Wang Yukun , Afonja Olubunmi , Ma Chunhong , Chen Youhai H. , Zhang Lining
Published: July 2010

Chemoresistance is a major cause of treatment failure in ovarian cancer. Therefore, it is necessary to explore alternative therapeutic methods to overcome drug resistance for ovarian cancer treatment. We previously reported that programmed cell death 4 (PDCD4), a tumor suppressor, significantly suppresses the malignant phenotype of ovarian cancer cells and its lost or low expression in ovarian cancer is associated with unfavorable prognosis of patients. Here we show that PDCD4 improves the sensitivity of ovarian cancer cells to platinum‐based chemotherapy. Overexpression of PDCD4 enhanced chemosensitivity in SKOV3 and CAOV3 cells with low levels of PDCD4, whereas knockdown of PDCD4 reduced chemosensitivity in OVCAR3 cells with high levels of PDCD4. Subsequently, the combination of enforced PDCD4 expression with cisplatin treatment significantly suppressed ovarian tumor growth in a xenograft animal model. The PDCD4 effect appears to be specific for cisplatin and carboplatin, not affecting cyclophosphamide, etoposide, or paclitaxel. Mechanistically, PDCD4 significantly increased cisplatin‐induced cleavage of caspase‐3 and caspase‐8, but had only a slight impact on caspase‐9 cleavage and the expression of Bax and Bcl‐2 in vitro and in vivo. A specific caspase‐8 inhibitor, Z‐ITED‐FMK, attenuated cisplatin‐induced apoptosis in PDCD4‐overexpressing ovarian cancer cells. Taken together, our results indicate that PDCD4 enhances cisplatin‐induced apoptosis by mainly activating the death receptor pathway, and PDCD4 gene transfer in combination with cisplatin therapy may break the resistance of ovarian cancer cells to chemotherapy. (Cancer Sci 2010)
P38 MAPK inhibition enhancing ATO‐induced cytotoxicity against multiple myeloma cells
Authors: Wen Jianguo , Cheng Haiyun Y. , Feng Yongdong , Rice Lawrence , Liu Shangfeng , Mo Albert , Huang James , Zu Youli , Ballon Douglas J. , Chang Chung‐Che
Published: July 2010

The resistance to arsenic trioxide (ATO) treatment is relatively common (55–80%) in multiple myeloma patients. This study found that ATO at clinically achievable concentrations (2–7 μmol/l) activated p38 mitogen‐activated protein kinase (MAPK) in both myeloma cell lines and primary myeloma cells, a finding not previously well‐documented in myeloma cells. Inhibition of p38 MAPK activation by pharmacological inhibitors (SB203580) or downregulation of p38 MAPK by siRNA significantly increased the apoptosis and/or growth inhibition induced by ATO treatment in myeloma cells. Combination of ATO and p38 MAPK inhibition abolished the interleukin‐6 enhanced protection of myeloma cells against ATO treatment. The ATO‐resistant cell line developed in our laboratory showed an increase in p38 MAPK activation. The increase of apoptosis by the combination of ATO and SB203580 was accompanied by the activation of caspase‐9 and caspase‐8 suggesting that both extrinsic and intrinsic apoptotic pathways are involved. Additionally, the p38 MAPK activation by ATO was associated with increased phosphorylation and upregulated expression of Heat shock protein 27. These results suggest that ATO‐induced p38 MAPK activation plays an important role in the resistance to ATO in myeloma cells and that p38 MAPK inhibition may overcome resistance to ATO treatment in myeloma patients.
Mast cells protect against airway Mycoplasma pneumoniae under allergic conditions
Authors: Michels N. M. , Chu H. W. , LaFasto S. C. , Case S. R. , Minor M. N. , Martin R. J.
Published: July 2010

Background
Infection with Mycoplasma pneumoniae (Mp) in asthma can occur both acutely and chronically with an associated Th2 inflammatory response and/or increased numbers of bronchial mast cells. Mast cells have previously been shown to promote mycoplasma clearance in mice; however, it is unknown whether mast cells would aid Mp clearance under allergic conditions.

Objective
Our aim was to determine the impact of allergic inflammation on mast cell‐mediated lung Mp clearance. Furthermore, as we have previously demonstrated an essential role for IL‐6 in lung Mp clearance we also investigated the role of mast cell‐derived IL‐6.

Methods
Mast cell‐deficient (WBB6F1/J‐KitW/KitW‐v) mice were challenged with ovalbumin to induce airway inflammation before Mp infection. The role of mast cell‐derived IL‐6 in bacterial clearance was further investigated by reconstitution of mast cell‐deficient mice with IL‐6−/− mast cells.

Results
Allergic mast cell‐deficient mice exhibited increased lung Mp burden compared with control littermates. Intravenous adoptive transfer of wild‐type and IL‐6−/− mast cells significantly improved Mp clearance in mast cell‐deficient mice. Acutely after Mp infection, allergen‐challenged mast cell‐deficient mice had increased levels of the pro‐inflammatory cytokines IL‐6 and TNF‐α in the bronchoalveolar lavage (BAL) fluid. The total number of neutrophils was also increased in mast cell‐deficient mice.

Conclusions
Our results establish that mast cells aid host defense against Mp in an allergic setting and that while IL‐6 is necessary for lung Mp clearance, mast cell‐derived IL‐6 is not required.

Cite this as: N. M. Michels, H. W. Chu, S. C. LaFasto, S. R. Case, M. N. Minor and R. J. Martin, Clinical & Experimental Allergy, 2010 (40) 1406–1413.
Hyaluronic acid metabolism is increased in unstable plaques
Authors: Bot Pieter T. , Pasterkamp Gerard , Goumans Marie‐José , Strijder Chaylendra , Moll Frans L. , De Vries Jean‐Paul , Pals Steven T. , De Kleijn Dominique P. , Piek Jan J. , Hoefer Imo E.
Published: July 2010

Eur J Clin Invest 2010; 40 (9): 818–827

Background  Hyaluronic acid is expressed in atherosclerotic lesions, but its exact role in atherosclerotic disease remains unknown. As degradation of hyaluronic acid by hyaluronidase into low molecular weight hyaluronic acid (LMW‐HA) is associated with inflammation and Matrix Metalloproteinase (MMP)‐9 activity, we hypothesized that hyaluronic acid metabolism is increased in plaques with unstable characteristics like large lipid core, high number of macrophages, MMP‐9 activity, low collagen and smooth muscle cell content.

Materials and methods  Protein was isolated from 68 carotid artery specimens. The adjacent plaque segment was characterized for the histological parameters: lipid core, macrophage, collagen, smooth muscle cell (SMC) content and the amount of intra‐plaque thrombus. Hyaluronidase activity, total hyaluronic acid and LMW‐HA expression, the standard hayaluronic acid receptor CD44s and the VEGF‐A binding isoform CD44v3, MMP‐9 activity and the plaque instability associated growth factor Vascular Endothial Growth Factor (VEGF)‐A were analysed and correlated with histological characteristics.

Results  Hyaluronidase activity, LMW‐HA and CD44 expression (CD44s, CD44v3) levels were increased in atheromatous plaques compared with fibrous plaques. Total hyaluronic acid did not correlate with plaque instability. MMP‐9 activity correlated with CD44s, hyaluronidase and LMW‐HA expression. CD44v3 correlated with the angiogenic factor VEGF‐A. In vitro stimulation of macrophages with LMW‐HA increased MMP‐9 activity.

Conclusions  We show for the first time that increased hyaluronic acid metabolism and elevated CD44 levels are associated with plaque destabilization potentially by increased MMP‐9 activity and stimulation of angiogenesis.
Risk factors and early detection of atherosclerosis in rheumatoid arthritis
Authors: De Groot Lodewijk , Posthumus Marcel D. , Kallenberg Cees G. M. , Bijl Marc
Published: July 2010

Eur J Clin Invest 2010; 40 (9): 835–842

Background  Patients with rheumatoid arthritis (RA) have an increased morbidity and mortality due to cardiovascular disease (CVD). This cannot be explained alone by the increased prevalence of traditional cardiovascular risk factors like smoking and hypertension. Other factors therefore seem to be involved in the pathogenesis of atherosclerosis in RA.

Methods  Literature was searched for epidemiology and pathophysiology of atherosclerosis in RA, with special focus on the role of advanced glycation end products (AGE’s), endothelial activation, endothelial dysfunction and premature atherosclerosis as measured by intima media thickness (IMT). Finally, a literature search was performed on therapeutic strategies to prevent atherosclerosis in RA.

Results  In RA increased AGE accumulation, endothelial activation, endothelial dysfunction and premature atherosclerosis can be identified. Treatment of RA activity by multiple disease modifying anti rheumatic drugs (DMARD’s) has shown to be effective in reducing premature atherosclerosis in RA.

Conclusion  Cardiovascular disease is increased in RA. Tight disease control and treatment of other risk factors is recommended to prevent morbidity and mortality due to CVD in RA.
Rapid decomposition of phytate applied to a calcareous soil demonstrated by a solution31P NMR study
Authors: Doolette A. L. , Smernik R. J. , Dougherty W. J.
Published: July 2010

myo‐Inositol hexakisphosphate (phytate) is widely regarded as an abundant form of soil organic phosphorus (P) in many soils. Its abundance is believed to be because of its resistance to microbial degradation. We examined the fate of phytate added to a calcareous soil as a solution at a concentration of 58 mg P kg−1, with and without the addition of wheat straw. The soil was incubated for 13 weeks, with phytate concentrations determined at 0, 1, 4, 7 and 13 weeks using NaOH‐EDTA soil extraction followed by31P nuclear magnetic resonance (NMR) spectroscopy. The phytate concentration declined rapidly, with 18% (phytate + wheat straw) and 12% (phytate) of the initial phytate remaining after 13 weeks. This coincided with an increase in the proportion of orthophosphate relative to total NaOH‐EDTA extractable P (from 65 to 81%) and a small increase inα‐ andβ‐glycerophosphate concentration, providing evidence for the microbial degradation of phytate. The decrease in phytate concentration was consistent with a first‐order decay with a half‐life for phytate of 4–5 weeks. This study demonstrates that in the calcareous soil examined, phytate was not highly stable, but a potentially biologically available form of P. In order to quantify the concentration of P species, we developed an improved method of spectral deconvolution. This method accounted for a broad signal (3.5–6.5 ppm) in the monoester region of the spectra that represented up to 23% of the total extractable P. We found that when this broad signal was not included, phytate concentrations were over‐estimated by up to 54%.
Ecological immunology and tolerance in plants and animals
Authors: Baucom Regina S. , de Roode Jacobus C.
Published: July 2010

1. Most animal studies of ecological immunology have focused on parasite resistance: defence mechanisms through which animals prevent infection or reduce parasite growth. Resistance mechanisms have obvious fitness benefits by reducing the fitness losses attributed to infection.

2. Intriguingly, animal researchers have largely ignored the role of tolerance mechanisms, through which hosts do not reduce parasite infection or growth, but alleviate the negative fitness consequences of parasite infection or growth instead. This omission stands in sharp contrast with the plant literature, where tolerance has been studied for decades and led to many important insights.

3. Here, we show that the plant literature has a lot to offer for understanding defence against parasites in animals. We argue that the prevailing views on tolerance in the plant literature should direct research on animals, and that theoretical ecological and evolutionary studies should be built on tolerance measures that are feasible and relevant in empirical studies.

4. Studying tolerance will enhance our understanding of how animals deal with parasites in their natural environments and may provide novel ways to combat disease.
Expressed sequence tags from the midgut of Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae)
Authors: Simpson R. M. , Newcomb R. D. , Gatehouse H. S. , Crowhurst R. N. , Chagné D. , Gatehouse L. N. , Markwick N. P. , Beuning L. L. , Murray C. , Marshall S. D. , Yauk Y.‐K. , Nain B. , Wang Y.‐Y. , Gleave A. P. , Christeller J. T.
Published: July 2010

The midgut is a key tissue in insect science. Physiological roles include digestion and peritrophic membrane function, as well as being an important target for insecticides. We used an expressed sequence tag (EST) approach to identify candidate genes and gene families involved in these processes in the light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae). Two cDNA libraries were constructed from dissected midgut of third to fifth instar larvae. Clustering analysis of 6416 expressed sequence tags produced 1178 tentative unique genes comprising 725 tentative contigs and 453 singletons. The sequences show similar codon usage to sequences from other lepidopterans, a Kozak consensus sequence similar to Drosophila and single nucleotide polymorphisms (SNPs) were detected at a frequency of 1.35/kb. The identity of the most common Interpro families correlates well with major known functions of the midgut. Phylogenetic analysis was conducted on representative sequences from selected multigene families. Gene families include a broad range of digestive proteases, lipases and carbohydrases that appear to have degradative capacity against the major food components found in leaves, the diet of these larvae; and carboxylesterases, glutathione‐S‐transferases and cytochrome P450 monooxygenases, potentially involved in xenobiotic degradation. Two of the larger multigene families, serine proteases and lipases, expressed a high proportion of genes that are likely to be catalytically inactive.
MTA and F‐doped MTA cements used as sealers with warm gutta‐percha. Long‐term study of sealing ability
Authors: Gandolfi M. G. , Prati C.
Published: July 2010

Gandolfi MG, Prati C. MTA and F‐doped MTA cements used as sealers with warm gutta‐percha. Long‐term study of sealing ability. International Endodontic Journal, 43, 889–901, 2010.

Aim  To evaluate the long‐term sealing ability (up to 6 months) of two experimental calcium silicate MTA cements used as root canal sealers in association with warm gutta‐percha.

Methodology  Calcium silicate (MTA) and calcium‐fluoro‐silicate powders were prepared. Sodium fluoride was included in FMTA (Fluoride‐doped Mineral Trioxide Aggregate) as an expansive and retardant agent. Single‐rooted teeth were instrumented with NiTi rotary instruments, filled with warm gutta‐percha in association with one of the experimental sealers or with AH Plus as a control (n = 20 for each sealer) and stored at 37 °C. Sealing was assessed at 24, 48 h, 1, 2 weeks and 1, 3, 6 months by a fluid filtration method. Scanning electron microscopy with energy dispersive analysis (SEM/EDX) was used to study the dentine/sealer interface of roots stored for 6 months and the surface of cement disks stored for 24 h.

Results  All sealers revealed a statistically significant reduction (P < 0.05) in fluid filtration after the first 2 weeks. No statistically significant differences were observed between FMTA and AH Plus at all analysis times. At short times (24, 48‐h), no statistically significant differences were found between the experimental cements and AH Plus. At long‐term evaluations (1, 3, 6 months), FMTA and AH Plus sealed significantly better (P < 0.05) than MTA. FMTA was associated with lower fluid filtration rates, and the seal was stable from 48 h to 6 months, thus proving the most effective material. Scanning electron microscopy with energy dispersive analysis of root sections filled with calcium silicate sealers revealed the formation of a blend layer of gutta‐percha and cement consequent to the warm gutta‐percha condensation technique. Scanning electron microscopy with energy dispersive analysis of 24‐h‐stored disks identified a Ca‐rich coating on the outer surface consisting of globular particles (calcium hydroxide and calcium carbonate), and a deeper internal Ca‐ and Si‐rich region consisting of needle‐like ettringite crystals and round formations of calcium silicate hydrate gel.

Conclusion  Fluoride‐doped MTA demonstrated stable sealing during a period of up to 6 months and significantly better than conventional calcium silicate MTA cements and comparable to AH Plus. The study supports the suitability of calcium silicate MTA cements as sealers in association with warm gutta‐percha for root filling.
Push‐out strength of methacrylate resin‐based sealers to root canal walls
Authors: Costa J. A. , Rached‐Júnior F. A. , Souza‐Gabriel A. E. , Silva‐Sousa Y. T. C. , Sousa‐Neto M. D.
Published: July 2010

Costa JA, Rached‐Júnior FA, Souza‐Gabriel AE, Silva‐Sousa YTC, Sousa‐Neto MD. Push‐out strength of methacrylate resin‐based sealers to root canal walls. International Endodontic Journal, 43, 698–706, 2010.

Aim  To assess the push‐out strength of Epiphany SE, Epiphany and Hybrid Root SEAL to the dentine walls of root canals.

Methodology  Sixty roots of canines were prepared and distributed to six groups (n = 10) according to the filling material: GI – Epiphany SE, GII – Epiphany primer and sealer, GIII – Epiphany primer, sealer and resinous solvent, GIV – Clearfil DC Bond and Epiphany sealer, GV – Clearfil, Epiphany sealer and solvent and GVI – Hybrid Root SEAL. Resilon cones were used in all groups. Roots were sectioned transversally to obtain three slices from each third. One slice was subjected to the push‐out test (MPa), and results were analysed by anova and Tukey’s test (P < 0.05). The other two slices were prepared for scanning electron microscopy (SEM). Failure mode was also analysed.

Results  A statistically significant difference (P <0.05) occurred between Hybrid Root SEAL (5.27 ± 2.07) and the other materials, GI (0.40 ± 0.23), GII (0.78 ± 0.45), GIII (0.57 ± 0.28), GIV (0.40 ± 0.24) and GV (0.50 ± 0.41), which did not differ significantly from each other (P > 0.05). Adhesive failures predominated in groups I, II, IV and V, whilst mixed and cohesive failures were the most frequent in groups III and VI, respectively. There were gaps in the adhesive interface of GI and GII, continuity areas of the filling material with dentine in GIV and GV and good adaptation of the interface of GVI.

Conclusion  Hybrid Root SEAL had greater push‐out strength to root canal dentine than Epiphany SE and Epiphany. The use of primer, solvent and adhesive system did not influence the adhesion of Epiphany.
Termination of pregnancy services: experiences of gynaecological nurses
Authors: Nicholson Jackie , Slade Pauline , Fletcher Joanne
Published: July 2010

nicholson j., slade p. & fletcher j. (2010) Termination of pregnancy services: experiences of gynaecological nurses. Journal of Advanced Nursing 66(10), 2245–2256.

Aim.  This paper is a report of a study to identify the experience of gynaecological nurses involved with termination of pregnancy.

Background.  Staff involved with termination of pregnancy have been found to experience both positive and negative views. Varying processes and experiences for staff have been identified, from termination of pregnancy work being emotionally draining and stressful to there being a process of care that evolves with greater experience.

Methods.  A purposive sample of seven gynaecological nurses currently working in a termination of pregnancy service was recruited. Data were collected between October 2007 and January 2008 using interviews and standardized questionnaires. Transcripts of the interviews were analysed using Interpretive Phenomenological Analysis.

Results.  Eight superordinate themes emerged from the analysis: (1) Unconditional acceptance and understanding of termination of pregnancy, (2) Strategies for managing the demands and challenges, (3) What we do for patients and job satisfaction, (4) Challenges to unconditional acceptance, (5) Juggling the contrasting needs and demands of patients, (6) The most demanding aspects of the role, (7) The significance of personal experience and (8) The service context. Some of the experiences were interpreted as ways in which nurses justified their role. The themes were understood in terms of a balance between strains, coping and contextual influences.

Conclusion.  Providing a recognized supportive supervisory environment might allow for the acknowledgement of the unique challenges staff in termination of pregnancy services face, and might enhance a sense of validation within the organization and hence staff wellbeing.
Vulnerability related to oral health in early childhood: a concept analysis
Authors: Mattheus Deborah J.
Published: July 2010

mattheus d.j. (2010) Vulnerability related to oral health in early childhood: concept analysis. Journal of Advanced Nursing 66(9), 2116–2125.

Aim.  This article is a report of the analysis of the concept of vulnerability and its relationship to oral health in early childhood.

Background.  Poor oral health is a continued problem for children worldwide. Vulnerability increases the probability of poor oral health outcomes. The lack of clarity of the concept of vulnerability creates difficulty in understanding this multi‐factoral condition.

Data sources.  Data source included 34 articles covering the period 2000–2009 from a variety of disciplines, including nursing, dentistry, medicine and public health.

Methods.  The concept analysis was conducted using Rodgers’ evolutionary method. The literature was analysed and a social ecology model was used to frame the discussion, recognizing family and community influences on children’s oral health.

Results.  The context of oral health in early childhood contributes to the changes in the concept vulnerability. The attributes are closely related to family and community factors and identified as limited parental income, parental education, community‐based services and fluoride; and exposure to poor parental habits, parental neglect and harmful toxins. The primary antecedent is identified as a form of limited protection from exposure to various circumstances.

Conclusion.  Children with limited protection have increased vulnerability and greater probability of poor health outcomes. Nurses who understand the concept of vulnerability related to oral health and can identify factors that create protection and are capable of decreasing vulnerability through parent education, community awareness and policy changes that support children and families.
Satisfaction Scale for Community Nursing: development and validation
Authors: Cheng Winnie Lai Sheung , Lai Claudia Kam Yuk
Published: July 2010

cheng w.l.s. & lai c.k.y. (2010) Satisfaction Scale for Community Nursing: development and validation. Journal of Advanced Nursing 66(10), 2331–2340.

Aim.  This study is a report of the development and testing of the Satisfaction Scale for Community Nursing for measuring patient satisfaction with community nursing.

Background.  Measuring patient satisfaction with a psychometrically sound instru‐ment is important if patient judgment is used as a quality indicator to evaluate the quality of the service.

Methods.  Service users and providers participated in generating items for a questionnaire related to the concept of patient satisfaction. A convenient sample of 121 patients receiving care from the Community Nursing Service was recruited to pilot the questionnaire for its initial validation in 2005. Content validity and factor analysis of the draft questionnaire were assessed. Psychometric properties of the final questionnaire were assessed using data from 80 patients in a validation study conducted during 2006.

Results.  A 17‐item satisfaction questionnaire with a five‐point Likert scale measuring three quality domains was developed: technical competence, coordination of services and interpersonal relationships in community nursing. Cronbach’s alpha was 0·90. Principal component analysis with varimax rotation yielded three factors with eigenvalues >1; these accounted for 76·6% of the total variance. The factor loadings of the items ranged from >0·64 to 0·84. The concurrent validity of the scale associated with two conceptually related variables was 0·61 (P < 0·05) and 0·66 (P < 0·05).

Conclusion.  The questionnaire may be valuable for assessing the satisfaction level of clients with community nursing service in meeting their expectations, and thus for enhancing treatment adherence and improving the quality of care.
Experiences of drug use and ageing: health, quality of life, relationship and service implications
Authors: Roe Brenda , Beynon Caryl , Pickering Lucy , Duffy Paul
Published: July 2010

roe b., beynon c., pickering l. & duffy p. (2010) Experiences of drug use and ageing: health, quality of life, relationship and service implications. Journal of Advanced Nursing 66(9), 1968–1979.

Aim.  This paper is a report of an exploration of older people’s experiences of substance use in the context of ageing, and its impact on health, quality of life, relationships and service use.

Background.  Use of illicit drugs by older people is a neglected policy, research and service provision and is generally perceived as a lifestyle of younger populations.

Method.  A convenience sample of 11 people aged 49–61 years (mean 57 years) in contact with voluntary sector drug treatment services participated in qualitative semi‐structured tape‐recorded interviews and thematic content analysis was performed. The data were collected in 2008.

Findings.  Drug use can have negative impacts on health status, quality of life, family relationships and social networks that accrue with age. Participants were identified as early or later onset users of drugs due to the impact of life events and relationships. A range of substances had been used currently and throughout their lives, with no single gateway drug identified as a prelude to personal drug careers. Life review and reflection were common, in keeping with ageing populations, along with regret of ever having started to use drugs. Living alone and their accommodation made them more susceptible to social isolation, and they reported experiences of death and dying of their contemporaries and family members earlier than usual in the life course.

Conclusion.  Older people who continue to use drugs and require the support of services for treatment and care are an important emerging population and their specific needs should recognized.
Effects of dietary fibre intake during adolescence on the components of the metabolic syndrome at the age of 36 years: the Amsterdam Growth and Health Longitudinal Study
Authors: Veldhuis L. , Koppes L. L. J , Driessen M. T , Samoocha D. , Twisk J. W. R
Published: July 2010

Background:  The prevalence of the metabolic syndrome is increasing, especially in young individuals. Most of the previous studies that have investigated the association between dietary fibre intake and the metabolic syndrome are cross‐sectional or of short duration, and their results are inconsistent. The present study investigated whether dietary fibre intake during adolescence has a protective effect on developing the metabolic syndrome as an adult.

Methods:  Data on dietary intake and metabolic syndrome components were derived from a healthy sample of 174 men and 194 women who were followed‐up from the age of 13 years onwards in the Amsterdam Growth and Health Longitudinal Study. Data were analysed with use of generalised estimating equations and linear regression analyses.

Results:  The mean dietary fibre intake was 9.9 g/4.0 MJ (1000 kcal) during adolescence and 10.8 g/4.0 MJ (1000 kcal) at age 36 years. The prevalence of the metabolic syndrome at age 36 years was 10.1%. No differences were found in the time‐course of dietary fibre intake between subjects with and those without the metabolic syndrome or its components. Dietary fibre intake during adolescence was not related to the components of the metabolic syndrome at age 36 years, except for an inverse relationship with waist circumference, where a gram/4.0 MJ (1000 kcal) higher fibre intake was associated with a 0.44 cm smaller waist circumference (P = 0.03, 95% CI −0.85 to −0.04).

Conclusions:  The present study found no association between dietary fibre intake and the metabolic syndrome in young adults. High fibre intake, however, was inversely associated with waist circumference.