bluuebunny/crossref_metadata_2025 huggingface dataset:
A uniformly accurate finite-element method for a singularly perturbed one-dimensional reaction-diffusion problem
Authors: O’Riordan Eugene , Stynes Martin
Published: June 2010

A finite-element method with exponential basis elements is applied to a selfadjoint, singularly perturbed, two-point boundary value problem. The tridiagonal difference scheme generated is shown to be uniformly second-order accurate for this problem (i.e., the nodal errors are bounded by

C

h
2

C{h^2}

, where C is independent of the mesh size h and the perturbation parameter). With a certain choice of trial functions, uniform first-order accuracy is obtained in

L
∞

[
0
,
1
]

{L^\infty }[0,1]

.
Symmetrization of the sinc-Galerkin method for boundary value problems
Authors: Lund John
Published: June 2010

The Sinc-Galerkin method developed in [5], when applied to the second-order selfadjoint boundary value problem, gives rise to a nonsymmetric coefficient matrix. The technique in [5] is based on weighting the Galerkin inner products in such a way that the method will handle boundary value problems with regular singular points. In particular, the method does an accurate job of handling problems with singular solutions (the first or a higher derivative of the solution is unbounded at one or both of the boundary points). Using n function evaluations, the method of [5] converges at the rate

exp
⁡
(
−
κ

n

)

\exp ( - \kappa \sqrt n )

, where k is independent of n. In this paper it is shown that, by changing the weight function used in the Galerkin inner products, the coefficient matrix can be made symmetric. This symmetric method is applicable to a slightly more restrictive set of boundary value problems than the method of [5], The present method, however, still handles a wide class of singular problems and also has the same

exp
⁡
(
−
κ

n

)

\exp ( - \kappa \sqrt n )

convergence rate.
A spectral Galerkin method for a boundary integral equation
Authors: McLean W.
Published: June 2010

We consider the boundary integral equation which arises when the Dirichlet problem in two dimensions is solved using a single-layer potential. A spectral Galerkin method is analyzed, suitable for the case of a smooth domain and smooth boundary data. The use of trigonometric polynomials rather than splines leads to fast convergence in Sobolev spaces of every order. As a result, there is rapid convergence of the approximate solution to the Dirichlet problem and all its derivatives uniformly up to the boundary.
Computing in the Jacobian of a hyperelliptic curve
Authors: Cantor David G.
Published: June 2010

In this paper we present algorithms, suitable for computer use, for computation in the Jacobian of a hyperelliptic curve. We present a reduction algorithm which is asymptotically faster than that of Gauss when the genus g is very large.
Implementation of a new primality test
Authors: Cohen H. , Lenstra A. K.
Published: June 2010

An implementation of the Cohen-Lenstra version of the Adleman-Pomerance-Rumely primality test is presented. Primality of prime numbers of up to 213 decimal digits can now routinely be proved within approximately ten minutes.
Primitive normal bases for finite fields
Authors: Lenstra H. W. , Schoof R. J.
Published: June 2010

It is proved that any finite extension of a finite field has a normal basis consisting of primitive roots.
The multiple polynomial quadratic sieve
Authors: Silverman Robert D.
Published: June 2010

A modification, due to Peter Montgomery, of Pomerance’s Quadratic Sieve for factoring large integers is discussed along with its implementation. Using it, allows factorization with over an order of magnitude less sieving than the basic algorithm. It enables one to factor numbers in the 60-digit range in about a day, using a large minicomputer. The algorithm has features which make it well adapted to parallel implementation.
Large integral points on elliptic curves
Authors: Zagier Don
Published: June 2010

We describe several methods which permit one to search for big integral points on certain elliptic curves, i.e., for integral solutions (x, y) of certain Diophantine equations of the form

y
2

=

x
3

+
a
x
+
b

(
a
,
b
∈

Z

)

{y^2} = {x^3} + ax + b\;(a,b \in {\mathbf {Z}})

in a large range

|

x

|

,

|

y

|

⩽
B

|x|,|y| \leqslant B

, in time polynomial in

log
⁡
log
⁡
B

\log \log B

. We also give a number of individual examples and of parametric families of examples of specific elliptic curves having a relatively large integral point.
Crosswind smear and pointwise errors in streamline diffusion finite element methods
Authors: Johnson C. , Schatz A. H. , Wahlbin L. B.
Published: June 2010

For a model convection-dominated singularly perturbed convection-diffusion problem, it is shown that crosswind smear in the numerical streamline diffusion finite element method is minimized by introducing a judicious amount of artificial crosswind diffusion. The ensuing method with piecewise linear elements converges with a pointwise accuracy of almost

h

5

/

4

{h^{5/4}}

under local smoothness assumptions.
The numerical viscosity of entropy stable schemes for systems of conservation laws. I
Authors: Tadmor Eitan
Published: June 2010

Discrete approximations to hyperbolic systems of conservation laws are studied. We quantify the amount of numerical viscosity present in such schemes, and relate it to their entropy stability by means of comparison. To this end, conservative schemes which are also entropy conservative are constructed. These entropy conservative schemes enjoy second-order accuracy; moreover, they can be interpreted as piecewise linear finite element methods, and hence can be formulated on various mesh configurations. We then show that conservative schemes are entropy stable, if and—for three-point schemes—only if they contain more viscosity than that present in the above-mentioned entropy conservative ones.
On the convergence of a finite element method for a nonlinear hyperbolic conservation law
Authors: Johnson Claes , Szepessy Anders
Published: June 2010

We consider a space-time finite element discretization of a time-dependent nonlinear hyperbolic conservation law in one space dimension (Burgers’ equation). The finite element method is higher-order accurate and is a Petrov-Galerkin method based on the so-called streamline diffusion modification of the test functions giving added stability. We first prove that if a sequence of finite element solutions converges boundedly almost everywhere (as the mesh size tends to zero) to a function u, then u is an entropy solution of the conservation law. This result may be extended to systems of conservation laws with convex entropy in several dimensions. We then prove, using a compensated compactness result of Murat-Tartar, that if the finite element solutions are uniformly bounded then a subsequence will converge to an entropy solution of Burgers’ equation. We also consider a further modification of the test functions giving a method with improved shock capturing. Finally, we present the results of some numerical experiments.
An a posteriori parameter choice for ordinary and iterated Tikhonov regularization of ill-posed problems leading to optimal convergence rates
Authors: Gfrerer Helmut
Published: June 2010

We propose an a posteriori parameter choice for ordinary and iterated Tikhonov regularization that leads to optimal rates of convergence towards the best approximate solution of an ill-posed linear operator equation in the presence of noisy data. Numerical examples are given.
The stable evaluation of multivariate simplex splines
Authors: Grandine Thomas A.
Published: June 2010

This paper gives a general method for the stable evaluation of multivariate simplex splines, based on the well-known recurrence relation of Micchelli [12]. This paper deals with two problems which arise in the implementation of the recurrence relation. First, the coefficients in the recurrence are shown to be efficiently computable via the dual simplex method of linear programminig. Secondly, the problem of evaluation along mesh boundaries is discussed in detail.
Testing a class of methods for solving minimization problems with simple bounds on the variables
Authors: Conn Andrew R. , Gould Nicholas I. M. , Toint Philippe L.
Published: June 2010

We describe the results of a series of tests for a class of new methods of trust region type for solving the simple bound constrained minimization problem. The results are encouraging and lead us to believe that the methods will prove useful in solving large-scale problems.
On approximate zeros and rootfinding algorithms for a complex polynomial
Authors: Kim Myong-Hi
Published: June 2010

In this paper we give criteria for a complex number to be an approximate zero of a polynomial f for Newton’s method or for the kth-order Euler method. An approximate zero for the kth-order Euler method is an initial point from which the method converges with an order

(
k
+
1
)

(k + 1)

Also, we construct families of Newton (and Euler) type algorithms which are surely convergent.
A nonlinear congruential pseudorandom number generator with power of two modulus
Authors: Eichenauer Jürgen , Lehn Jürgen , Topuzoğlu Alev
Published: June 2010

A nonlinear congruential pseudorandom number generator is studied where the modulus is a power of two. Investigation of this generator was suggested by Knuth [7]. A simple necessary and sufficient condition is given for this generator to have the maximal period length.
On the computation of totally real quartic fields of small discriminant
Authors: Buchmann Johannes , Ford David
Published: June 2010

All totally real quartic fields of discriminant less than

10
6

{10^6}

are computed. The method used to generate the fields is derived from Delone and Faddeev, with corrections and improvements. A new method for deciding field isomorphism is used to eliminate redundant examples. Integral bases and Galois groups are given for each field.
On the convergence of the 𝑝-version of the boundary element Galerkin method
Authors: Stephan E. P. , Suri M.
Published: June 2010

We prove convergence for the p-version of Galerkin boundary element schemes applied to various first-kind integral equations. We establish optimal error estimates for the p-version in the

H

1

/

2

{H^{1/2}}

and

H

−
1

/

2

{H^{ - 1/2}}

-norms and also derive rates of convergence in slightly stronger norms when the exact nature of the singularity of the solution is known. Our results lead to a boundary element method for two-dimensional screen problems in acoustics, which has twice the rate of convergence of the usual h-version with uniform mesh. An application to three-dimensional exterior problems is also analyzed.
Convergence of a random walk method for the Burgers equation
Authors: Roberts Stephen
Published: June 2010

We show that the solution of the Burgers equation can be approximated in

L
1

(

R

)

{L^1}({\mathbf {R}})

, to within

O
(

m

−
1

/

4

(
ln
⁡
m

)
2

)

O({m^{ - 1/4}}{(\ln m)^2})

, by a random walk method generated by

O
(
m
)

O(m)

particles. The nonlinear advection term of the equation is approximated by advecting the particles in a velocity field induced by the particles. The diffusive term is approximated by adding an appropriate random perturbation to the particle positions. It is also shown that the corresponding viscous splitting algorithm approximates the solution of the Burgers equation in

L
1

(

R

)

{L^1}({\mathbf {R}})

to within

O
(
k
)

O(k)

when k is the size of the time step. This work provides the first proof of convergence in a strong sense, for a random walk method, in which the related advection equation allows for the formation of shocks.
Comparison of Birkhoff type quadrature formulae
Authors: Bojanov Borislav , Nikolov Geno
Published: June 2010

The classical approach to the theory of quadrature formulae is based on the concept of algebraic degree of precision (ADP). A quadrature formula

Q
1

{Q_1}

is considered to be "better" than

Q
2

{Q_2}

if

ADP

(

Q
1

)
>

ADP

(

Q
2

)

{\text {ADP}}({Q_1}) > {\text {ADP}}({Q_2})

. However, there are many quadratures that use the same number of evaluations of the integrand and have the same ADP. Then, how should one compare such formulae? We show in this paper that the error of the quadrature depends monotonically on the type of data used. Roughly speaking, the lower the order of the derivatives used, the smaller is the error. As a consequence of the main result we demonstrate the existence of Birkhoff quadrature formulae of double precision.
The Runge-Kutta local projection discontinuous Galerkin finite element method for conservation laws. IV. The multidimensional case
Authors: Cockburn Bernardo , Hou Suchung , Shu Chi-Wang
Published: June 2010

In this paper we study the two-dimensional version of the Runge-Kutta Local Projection Discontinuous Galerkin (RKDG) methods, already defined and analyzed in the one-dimensional case. These schemes are defined on general triangulations. They can easily handle the boundary conditions, verify maximum principles, and are formally uniformly high-ordrr accurate. Preliminary numerical results showing the performance of the schemes on a variety of initial-boundary value problems are shown.
Lattice rules: projection regularity and unique representations
Authors: Sloan I. H. , Lyness J. N.
Published: June 2010

We introduce a unique characterization for lattice rules which are projection regular. Any such rule, having invariants

n
1

,

n
2

,
…
,

n
s

{n_1},{n_2}, \ldots ,{n_s}

, may be expressed, uniquely, in the form
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper Q f equals StartFraction 1 Over n 1 n 2 midline-horizontal-ellipsis n Subscript s Baseline EndFraction sigma-summation sigma-summation midline-horizontal-ellipsis sigma-summation f overbar left-parenthesis StartFraction j 1 bold z 1 Over n 1 EndFraction plus StartFraction j 2 bold z 2 Over n 2 EndFraction plus midline-horizontal-ellipsis plus StartFraction j Subscript s Baseline bold z Subscript s Baseline Over n Subscript s Baseline EndFraction right-parenthesis comma">

Q
f
=

1

n
1

n
2

⋯

n
s

∑

∑
⋯
∑

f
¯

(

j
1

z

1

n
1

+

j
2

z

2

n
2

+
⋯
+

j
s

z

s

n
s

)

,

Qf = \frac {1}{{{n_1}{n_2} \cdots {n_s}}}\sum {\sum \cdots \sum {\bar f} \left ( {\frac {{{j_1}{{\mathbf {z}}_1}}}{{{n_1}}} + \frac {{{j_2}{{\mathbf {z}}_2}}}{{{n_2}}} + \cdots + \frac {{{j_s}{{\mathbf {z}}_s}}}{{{n_s}}}} \right )} ,

\]
where the matrix

Z
=

(

z

1

,

z

2

,
…
,

z

s

)
T

Z = {({{\mathbf {z}}_1},{{\mathbf {z}}_2}, \ldots ,{{\mathbf {z}}_s})^T}

is upper unit triangular and individual elements satisfy

0
≤

z
r

(
c
)

>
(

n
r

/

n
c

)
,
r
>
c

0 \leq z_r^{(c)} > ({n_r}/{n_c}),r > c

.
Calculation of Gauss quadrature rules
Authors: Golub Gene H. , Welsch John H.
Published: June 2010

Several algorithms are given and compared for computing Gauss quadrature rules. It is shown that given the three term recurrence relation for the orthogonal polynomials generated by the weight function, the quadrature rule may be generated by computing the eigenvalues and first component of the orthornormalized eigenvectors of a symmetric tridiagonal matrix. An algorithm is also presented for computing the three term recurrence relation from the moments of the weight function.
Acquired reactive perforating collagenosis: Current status
Authors: KARPOUZIS Anthony , GIATROMANOLAKI Alexandra , SIVRIDIS Efthimios , KOUSKOUKIS Constantin
Published: June 2010

Acquired reactive perforating collagenosis is a unique perforating dermatosis, characterized clinically by umbilicated hyperkeratotic papules or nodules and histologically by a focal hyperkeratosis in direct contact with transepidermal perforating dermal collagen. Several inflammatory or malignant systemic diseases may coexist with acquired reactive perforating collagenosis. The possible biochemical or immunological mechanisms of the systemic diseases, potentially responsible for the development and appearance of acquired reactive perforating collagenosis, are still under investigation. Several topical treatments, ultraviolet B phototherapy and allopurinol p.o. administration may be effective.
Tetracycline and niacinamide control bullous pemphigoid but not pemphigus foliaceus when these conditions coexist
Authors: SHIOHARA Junko , YOSHIDA Kanako , HASEGAWA Junichi , UHARA Hisashi , TAKATA Minoru , SAIDA Toshiaki , OYAMA Bungo , HASHIMOTO Takashi
Published: June 2010

Pemphigus and pemphigoid are different types of autoimmune bullous disease and can occur in the same patient. We report a female patient with this condition. At first, we diagnosed her with bullous pemphigoid, and we treated her with tetracycline, niacinamide and a topical steroid. Tense bullas disappeared shortly after that, but crusted erythemas mainly on her head and trunk persisted. We examined BP180 and desmoglein 1 enzyme‐linked immunosorbent assays, and also histological features, which showed coexistence of bullous pemphigoid and pemphigus foliaceus concurrently. Therefore, we tried prednisolone, which could control both conditions. This case showed that tetracycline and niacinamide could control bullous pemphigoid, but could not control pemphigus foliaceus, and that prednisolone was effective for both conditions.
Mass spectrometry‐based metabolomics application to identify quantitative resistance‐related metabolites in barley against Fusarium head blight
Authors: BOLLINA VENKATESH , KUMARASWAMY G. KENCHAPPA , KUSHALAPPA AJJAMADA C. , CHOO THIN MIEW , DION YVES , RIOUX SYLVIE , FAUBERT DENIS , HAMZEHZARGHANI HABIBALLAH
Published: June 2010

Quantitative resistance is generally controlled by several genes. More than 100 resistance quantitative trait loci (QTLs) have been identified in wheat and barley against Fusarium head blight (FHB), caused by Gibberella zeae (anamorph: Fusarium graminearum), implying the possible occurrence of several resistance mechanisms. The objective of this study was to apply metabolomics to identify the metabolites in barley that are related to resistance against FHB. Barley genotypes, Chevron and Stander, were inoculated with mock or pathogen during the anthesis stage. The disease severity was assessed as the proportion of spikelets diseased. The genotype Chevron (0.33) was found to have a higher level of quantitative resistance than Stander (0.88). Spikelet samples were harvested at 48 h post‐inoculation; metabolites were extracted and analysed using an LC‐ESI‐LTQ‐Orbitrap (Thermo Fisher, Waltham, MA, USA). The output was imported to an XCMS 1.12.1 platform, the peaks were deconvoluted and the adducts were sieved. Of the 1826 peaks retained, a t‐test identified 496 metabolites with significant treatment effects. Among these, 194 were resistance‐related (RR) constitutive metabolites, whose abundance was higher in resistant mock‐inoculated than in susceptible mock‐inoculated genotypes. Fifty metabolites were assigned putative names on the basis of accurate mass, fragmentation pattern and number of carbons in the formula. The RR metabolites mainly belonged to phenylpropanoid, flavonoid, fatty acid and terpenoid metabolic pathways. Selected RR metabolites were assayed in vitro for antifungal activity on the basis of fungal biomass production. The application of these RR metabolites as potential biomarkers for screening and the potential of mass spectrometry‐based metabolomics for the identification of gene functions are discussed.
Curcumin disrupts meiotic and mitotic divisions via spindle impairment and inhibition of CDK1 activity
Authors: Bielak‐Zmijewska A. , Sikora‐Polaczek M. , Nieznanski K. , Mosieniak G. , Kolano A. , Maleszewski M. , Styrna J. , Sikora E.
Published: June 2010

Objectives:  Curcumin, a natural compound, is a potent anti‐cancer agent, which inhibits cell division and/or induces cell death. It is believed that normal cells are less sensitive to curcumin than malignant cells; however, the mechanism(s) responsible for curcumin’s effect on normal cells are poorly understood. The aim of this study was to verify the hypothesis that curcumin affects normal cell division by influencing microtubule stability, using mouse oocyte and early embryo model systems.

Materials and methods:  Maturating mouse oocytes and two‐cell embryos were treated with different concentrations of curcumin (10–50 μm), and meiotic resumption and mitotic cleavage were analysed. Spindle and chromatin structure were visualized using confocal microscopy. In addition, acetylation and in vitro polymerization of tubulin, in the presence of curcumin, were investigated and the damage to double‐stranded DNA was studied using γH2A.X. CDK1 activity was measured.

Results and conclusions:  We have shown for the first time, that curcumin, in a dose‐dependent manner, delays and partially inhibits meiotic resumption of oocytes and inhibits meiotic and mitotic divisions by causing disruption of spindle structure and does not induce DNA damage. Our analysis indicated that curcumin affects CDK1 kinase activity but does not directly affect microtubule polymerization and tubulin acetylation. As our study showed that curcumin impairs generative and somatic cell division, its future clinical use or of its derivatives with improved bioavailability after oral administration, should take into consideration the possibility of extensive side‐effects on normal cells.
Expression phenotype changes of EBV‐transformed lymphoblastoid cell lines during long‐term subculture and its clinical significance
Authors: Lee J.‐E. , Nam H.‐Y. , Shim S.‐M. , Bae G.‐R. , Han B.‐G. , Jeon J.‐P.
Published: June 2010

Objectives:  The EBV‐transformed lymphoblastoid cell line (LCL) is a useful resource for population‐based human genetic and pharmacogenetic studies. The principal objective here was to assess expression phenotype changes during long‐term subculture of LCLs, and its clinical significance.

Materials and methods:  We searched for genes that were differentially expressed in 17 LCLs at late (p161) passage compared to early passage (p4) using microarray assay, then validated them by real‐time RT‐PCR analysis. In addition, we estimated correlations between expression phenotypes of 20 LCL strains at early passage and 23 quantitative clinical traits from blood donors of particular LCL strains.

Results:  Transcript sequences of 16 genes including nuclear factor‐κB (NF‐κB) pathway‐related genes (such as PTPN13, HERC5 and miR‐146a) and carcinogenesis‐related genes (such as XAF1, TCL1A, PTPN13, CD38 and miR‐146a) were differentially expressed (>2‐fold change) in at least 15 of the 17 LCL strains. In particular, TC2N, FCRL5, CD180, CD38 and miR‐146a were downregulated in all 17 of the evaluated LCL strains. In addition, we identified clinical trait‐associated expression phenotypes in LCLs.

Conclusion:  Our results showed that LCLs acquired expression phenotype changes involving expression of NF‐κB pathway‐ and carcinogenesis‐related genes during long‐term subculture. These differentially expressed genes can be considered to be a gene signature of LCL immortalization or EBV‐induced carcinogenesis. Clinical trait‐associated expression phenotypes should prove useful in the discovery of new candidate genes for particular traits.
Optimization of culture conditions for endothelial progenitor cells from porcine bone marrow in vitro
Authors: Jianguo W. , Tianhang L. , Hong Z. , Zhengmao L. , Jianwei B. , Xuchao X. , Guoen F.
Published: June 2010

Objectives:  The aim of this study was to determine an optimal culture method for porcine bone marrow‐derived endothelial progenitor cells (EPCs).

Materials and methods:  Mononuclear cells (MNCs) were isolated by density centrifugation and differentiated into EPCs in in vitro. At first‐passage, EPCs were cultured at different cell densities (5 × 103, 1 × 104, 2 × 104 or 5 × 104/cm2) and in basic medium (EGM, medium 199, DMEM or 1640) supplemented with FBS (2%, 5%, 10% or 20%) and different combinations of cytokines (VEGF, VEGF + bFGF, VEGF + bFGF + EGF, or VEGF + bFGF + EGF + IGF), the experiment being based on L64 (421) orthogonal design.

Results and conclusions:  This demonstrated that the optimal culture method for our EPCs displayed higher expansion and migration rates as compared to other groups, by analysis of variance; that is, cultured at 1 × 104/cm2 in M199 supplemented with 10% FBS and VEGF + bFGF + IGF + EGF. Furthermore, percentage of positive cells stained by Dil‐ac‐LDL and FITC‐UEA‐1 was more than 65%, and as shown by immunohistochemistry, these cells also stained positively for CD133, CD34 and KDR. The present study indicates that the number and function of porcine EPCs significantly increased when using our optimized culture parameters.
Inhibition of cell proliferation by CD44: Akt is inactivated and EGR‐1 is down‐regulated
Authors: Zhang L.‐S. , Ma H.‐W. , Greyner H. J. , Zuo W. , Mummert M. E.
Published: June 2010

Objective: CD44 is a transmembrane glycoprotein and can facilitate signal transduction by serving as a platform for molecular recruitment and assembly. A number of studies have suggested that CD44 can either positively or negatively regulate cell proliferation. The purpose of this study was to investigate how CD44 can inhibit cell proliferation.

Materials and methods: We engineered E6.1 Jurkat cells to express CD44. Importantly, these cells lack endogenous CD44 expression. Molecular pathways involved with cell proliferation were studied using RT2‐PCR array, siRNA, Western blotting and by employing pharmacological inhibitors of ERK1/2, p38 and the PI3K/Akt pathways.

Results: We found that CD44 expression significantly inhibited cell proliferation and down‐regulated EGR‐1 expression and EGR‐1 targets cyclin D1 and cyclin D2. Transfection of control E6.1 Jurkat cells with EGR‐1 siRNA also inhibited cell proliferation, confirming its role. Disruption of the PI3K/Akt pathway with pharmacological inhibitors reduced both EGR‐1 expression and cell proliferation, recapitulating the properties of CD44 expressing cells. Akt was hypophosphorylated in cells expressing CD44 showing its potential role in negatively regulating Akt activation. Strikingly, constitutively active Akt rescued the proliferation defect showing requirement for active Akt, in our system.

Conclusion: Our results suggest a novel pathway by which CD44 inactivates Akt, down‐regulates EGR‐1 expression and inhibits cell proliferation.
Roles of Hes genes in neural development
Authors: Kageyama Ryoichiro , Ohtsuka Toshiyuki , Kobayashi Taeko
Published: June 2010

Hes genes are mammalian homologues of Drosophila hairy and Enhancer of split, which encode basic helix‐loop‐helix (bHLH) transcriptional repressors. In the developing central nervous system, Hes1, Hes3 and Hes5 are highly expressed by neural stem cells. Inactivation of these Hes genes leads to upregulation of proneural genes, acceleration of neurogenesis and premature depletion of neural stem cells. Conversely, overexpression of Hes genes leads to inhibition of neurogenesis and maintenance of neural stem cells. At later stages of development, Hes genes promote gliogenesis. Furthermore, Hes genes regulate maintenance of boundaries, which partition the nervous system into many compartments and endow the neighboring compartments with regional identities by secreting morphogens. Boundary cells usually proliferate slowly and do not give rise to neurons, unlike neural stem cells in compartments. Interestingly, these different characteristics between boundary cells and compartmental neural stem cells are regulated by different modes of Hes1 expression, which is variable in neural stem cells in compartments and persistent and high in boundary cells. Thus, Hes genes play an essential role in neural development by regulating proliferation, differentiation and specification of neural stem cells.
Roles of planar cell polarity pathway genes for neural migration and differentiation
Authors: Wada Hironori , Okamoto Hitoshi
Published: June 2010

Planar cell polarity (PCP) in epithelial cells is essential for the organization of tissues and their functions. The conserved non‐canonical Wnt/PCP pathway regulates this process in both Drosophila and vertebrates. However, recent studies have revealed that a similar set of genes, which may not be related to PCP, regulates oriented cell movement during development. In the present review, recent findings on neural migration in zebrafish hindbrain and axonal guidance in mouse forebrain and spinal cord are discussed. Future analyses on defects in vertebrate PCP mutants will provide novel insights into the conserved and diverse roles of non‐canonical Wnt/PCP pathway genes in vertebrate brain development.
Developmental anatomy of reeler mutant mouse
Authors: Katsuyama Yu , Terashima Toshio
Published: June 2010

The reeler mouse is one of the most famous spontaneously occurring mutants in the research field of neuroscience, and this mutant has been used as a model animal to understand mammalian brain development. The classical observations emphasized that laminar structures of the reeler brain are highly disrupted. Molecular cloning of Reelin, the gene responsible for reeler mutant provided insights into biochemistry of Reelin signal, and some models had been proposed to explain the function of Reelin signal in brain development. However, recent reports of reeler found that non‐laminated structures in the central nervous system are also affected by the mutation, making function of Reelin signal more controversial. In this review, we summarized reported morphological and histological abnormalities throughout the central nervous system of the reeler comparing to those of the normal mouse. Based on this overview of the reeler abnormalities, we discuss possible function of Reelin signal in the neuronal migration and other morphological events in mouse development.
Intra‐arterial chemotherapy for retinoblastoma: the beginning of a long journey
Authors: Shields Carol L , Shields Jerry A
Published: June 2010

Abstract

Conservative management of retinoblastoma has evolved from external beam radiotherapy to systemic chemotherapy by intravenous route and now to localized chemotherapy by intra‐arterial route in some cases. With 16‐year experience, systemic chemotherapy has been found effective for minimal to moderately advanced retinoblastoma with tumour control of 90% or better, few side effects and even hope for return of some vision. Localized intra‐arterial chemotherapy with delivery under fluoroscopy and catheterization of the ophthalmic artery is now undergoing evaluation and appears to provide striking control for retinoblastoma, particularly recurrent tumour seeds following other therapies. The limitations and complications of this approach have yet to be defined. Toxicity of the chemotherapy to the delicate retinal vessels is unknown. Despite its allure, intra‐arterial chemotherapy should be used with caution, as in other fields of paediatric oncology it has been found to provide no advantage over intravenous chemotherapy. Time will tell.
Recurrent idiopathic neuroretinitis: natural history and effect of treatment
Authors: Sundaram Seema V , Purvin Valerie A , Kawasaki Aki
Published: June 2010

Abstract

Background:  Previous reports have emphasized the self‐limited nature of idiopathic neuroretinitis. There is less information about a subgroup of patients who suffer recurrent episodes with worse visual outcome. We sought to better characterize the clinical features of recurrent idiopathic neuroretinitis including the effects of immunosuppressive treatment.

Methods:  Retrospective chart review of neuroretinitis patients from a single institution from 1983 to 2008. Inclusion criteria included two or more episodes of acute visual loss with disc oedema and macular exudates in a star pattern. Cases due to a specific infectious or inflammatory aetiology were excluded.

Results:  Forty‐one patients were included with an average follow up of 67 months. Median age at the time of the first episode was 28 years (range 10–54 years). Attacks were bilateral sequential in 34 patients (83%). We documented a total of 147 episodes in 75 eyes with an average of 3.6 attacks per patient. The average interval between attacks was 3 years. Visual field loss had a nerve fibre bundle pattern in most cases. Only 36% of eyes retained 6/12 or better visual acuity and greater than two‐thirds of their visual field. Long‐term immunosuppressive treatment in 13 patients decreased the attack rate by 72%.

Conclusions:  Recurrent idiopathic neuroretinitis typically affects young adults, with no gender preference. Recovery is limited and visual loss is cumulative with repeated attacks, often resulting in severe permanent visual loss. Immunosuppressive treatment appears to lessen the attack frequency.
Soil fertility and fine root dynamics in response to 4 years of nutrient (N, P, K) fertilization in a lowland tropical moist forest, Panama
Authors: YAVITT JOSEPH B. , HARMS KYLE E. , GARCIA MILTON N. , MIRABELLO MATT J. , WRIGHT S. JOSEPH
Published: June 2010

The question of how tropical trees cope with infertile soils has been challenging to address, in part, because fine root dynamics must be studiedin situ. We used annual fertilization with nitrogen (N as urea, 12.5 g N m−2 year−1), phosphorus (P as superphosphate, 5 g P m−2 year−1) and potassium (K as KCl, 5 g K m−2 year−1) within 38 ha of old‐growth lowland tropical moist forest in Panama and examined fine root dynamics with minirhizotron images. We expected that added P, above all, would (i) decrease fine root biomass but, (ii) have no impact on fine root turnover. Soil in the study area was moderately acidic (pH = 5.28), had moderate concentrations of exchangeable base cations (13.4 cmol kg−1), low concentrations of Bray‐extractable phosphate (PO4 = 2.2 mg kg−1), and modest concentrations of KCl‐extractable nitrate (NO3 = 5.0 mg kg−1) and KCl‐extractable ammonium (NH4 = 15.5 mg kg−1). Added N increased concentrations of KCl‐extractable NO3and acidified the soil by one pH unit. Added P increased concentrations of Bray‐extractable PO4and P in the labile fraction. Concentrations of exchangeable K were elevated in K addition plots but reduced by N additions. Fine root dynamics responded to added K rather than added P. After 2 years, added K decreased fine root biomass from 330 to 275 g m−2. The turnover coefficient of fine roots <1 mm diameter ranged from 2.6 to 4.4 per year, and the largest values occurred in plots with added K. This study supported the view that biomass and dynamics of fine roots respond to soil nutrient availability in species‐rich, lowland tropical moist forest. However, K rather than P elicited root responses. Fine roots smaller than 1 mm have a short lifetime (<140 days), and control of fine root production by nutrient availability in tropical forests deserves more study.
Shareholder Activism and Middle Management Equity Incentives
Authors: Marler Janet H. , Faugère Christophe
Published: June 2010

Manuscript Type: Empirical

Research Question/Issue: We examine how various types of shareholder activists (such as pension funds and large blockholders) impact the relative use of equity incentives at the middle management level of the firm and compare this with the impact on CEO incentive alignment.

Research Findings/Insights: Using a sample of 124 US technology firms over the period 1997–2001, we find evidence indicating voice activist shareholders, using communication pressure, are associated with the greater use of equity incentives, and higher total compensation at middle managerial levels, relative to exit activists, who exert economic pressure. The results for CEO equity incentives are similar. We also find that as the presence of institutional ownership siding with management (banks and insurance companies) increases relative to voice activists, the use of equity incentives at middle managerial levels declines. Results for CEO equity incentives are not the same.

Theoretical/Academic Implications: In agreement with contingent agency theory, we predict and find evidence of differing governance mechanisms used by voice activists (e.g., public pension funds) and exit activists (e.g., large shareholders). Voice activists face a higher cost of monitoring managers as compared to exit activists, and thus they will advocate for the heavier use of equity incentive compensation at the middle managerial level. In agreement with a managerial power perspective, however, we also find the use of equity incentives for middle managers decreases as the proportion of institutional ownership siding with the CEO increases.

Practitioner/Policy Implications: Shareholder activism plays a key role in aligning managerial interests below the CEO level; however, different types of shareholders have different economic and political interests in how equity compensation is shaped to achieve this. Exit activists use monitoring and voice activists substitute equity compensation for monitoring. Shareholders siding with management may also reduce the use of equity incentives for middle managers. These differing interests should be considered in crafting policy responses.
Physicochemical, microbiological, textural and sensory characterisation of Mexican Añejo cheese
Authors: HERNÁNDEZ‐MORALES CAROLINA , HERNÁNDEZ‐MONTES ARTURO , AGUIRRE‐MANDUJANO ELEAZAR , DE GANTE ABRAHAM VILLEGAS
Published: June 2010

The physicochemical, microbiological, textural and sensory characteristics of Mexican Añejo cheese were studied, as well as the composition of the raw milk used for its production. Differences in cheese (moisture, fat, NaCl, titratable acidity, pH, free volatile fatty acids, total viable count and total coliform count, texture and colour) and process milk were observed. A lexicon of 20 descriptors was generated by a 13 member trained panel using descriptive sensory analysis. Global acceptability was assessed by consumers (n = 60) using a nine point hedonic scale. Analysis of variance, internal preference mapping and PLS1 showed a greater acceptability for cheese with higher scores for buttery, crumbly and moisture. However, the least preferred cheese presented greater scores for the attributes: global taste duration, fishy, feet aroma, propionic acid, bitter, astringent and pungent.
Neuroprotective effects of ultra‐low‐molecular‐weight heparin in vitro and vivo models of ischemic injury
Authors: Zhang Zhi‐guo , Lü Tai‐sheng , Yuan Hong‐ying
Published: June 2010

This study was conducted to demonstrate ultra‐low‐molecular‐weight heparin’s neuroprotective effects on ischemic injury both in vivo and in vitro studies. In vitro, the effect of ultra‐low‐molecular‐weight heparin was tested in cultured PC12 cells exposed to Earle’s solution containing sodium dithionite, to identify its neuroprotection to PC12 cells damaged by oxygen‐glucose deprivation (OGD). The cell injury was detected by the tetrazolium salt 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5 diphenyl‐2H tetrazolium bromide (MTT) assay. In vivo, male Wistar rats with middle cerebral artery occlusion were evaluated for infarct volume followed by the treatment with ultra‐low‐molecular‐weight heparin. The results in vitro showed that ultra‐low‐molecular‐weight heparin significantly inhibited PC12 cells damage induced by OGD. Results in vivo showed that vein injection of Ultra‐Low‐molecular‐weight heparin at doses of 0.5 and 1.0 mg/kg exerted significant neuroprotective effects on rats with focal cerebral ischemic injury by significantly reducing the infarct volume compared with the injury group. All the findings suggest that ultra‐low‐molecular‐weight heparin might act as a neuroprotective agent useful in the treatment of cerebral ischemia.
Occult hepatitis B virus infection in pregnant woman and its clinical implication
Authors: Kwon Chang‐II , Hwang Seong Gyu , Shin Seung Ju , Chang Sung Woon , Kim Su Youn , Ko Kwang Hyun , Hong Sung Pyo , Park Pil Won , Rim Kyu Sung , Kang Myung Seo , Chung Hyun Jae , Hong Sun Pyo
Published: June 2010

Background/Aims: The objective of this study was to document the prevalence rate of occult hepatitis B virus (HBV) in healthy pregnant woman and the possibility of transmission to the foetus.

Methods: This study was performed prospectively with 202 healthy pregnant women. HBV‐DNA testing was performed using two specific quantitative tests with two independent sets of sera and cord blood. DNA sequencing analysis was carried out to confirm the specificity of polymerase chain reaction (PCR) product of HBV‐DNA testing.

Results: Eight of 202 (4%) individuals with the TaqMan PCR assay and 23 of 202 (11.4%) with the COBAS Amplicor HBV Monitor test were HBV‐DNA positive. Six (3%) individuals were positive with both methods. Sequencing and genotyping analysis of HBV polymerase gene with sera of the 75th subject resulted in genotype C. HBV‐DNA testing with four cord blood samples showed that all were HBV‐DNA negative.

Conclusion: Occult HBV infection shows a difference in prevalence rate depending on the test method but the existence has been confirmed by sequencing analysis. Our results also suggest that vertical transmission through the cord blood is not so high as to be clinical problems and warrants further investigation.
Atrophy of the residual alveolar ridge following tooth loss in an historical population
Authors: Reich KM , Huber CD , Lippnig WR , Ulm C , Watzek G , Tangl S
Published: June 2010

Oral Diseases (2010) 17, 33–44

Objectives:  To study the natural aetiopathology of jaw atrophy after tooth loss, unaltered by prosthetic procedures, an historical population without modern dental treatment was examined.

Methods:  Based on the hypothesis that there are predictable changes in shape during jaw‐atrophy, frequency and degree of atrophy as well as clinical aspects of bone quality and resorption were determined in the skeletal remains of 263 individuals. The potential association between age and frequency/severity of atrophy was analysed.

Results:  Atrophy in at least one jaw segment was present in 45.2% of the analysed jaw specimens. The residual ridge underwent a series of changes in shape and height following the pattern of resorption described for modern populations. The severity of these alterations was associated with the age of the individual and the region within the jaw. Atrophy was frequently related to structural degradation of the covering cortical layer.

Conclusions:  These findings prove that atrophy of the jaw evidently does occur, displaying similar patterns of resorption in a population without modern prosthetics, where the negative effect of ill‐fitting dentures is excluded. The basic information about alterations of shape and the cortical layer covering the residual crest might help to provide a deeper insight into aetiopathological mechanisms of this common oral disease.
Improved visualization of low abundance oral fluid proteins after triple depletion of alpha amylase, albumin and IgG
Authors: Krief G , Deutsch O , Gariba S , Zaks B , Aframian DJ , Palmon A
Published: June 2010

Oral Diseases (2010) 17, 45–52

Objectives:  The aim of this study was to examine whether triple depletion of salivary‐α‐amylase (sAA), albumin (Alb) and immunoglobulins G (IgGs) may improve the visualization capability of proteins in two‐dimensional gel electrophoresis (2‐DE) of oral fluids (OF).

Subjects and Methods:  Oral fluids from healthy volunteers were subjected sequentially to sAA removing device followed by application to an Alb and IgG immunoaffinity column (triple depletion). The depleted OF samples were analyzed using SDS‐PAGE followed by 2‐DE and protein identification using ion‐trap mass spectrometry (MS).

Results:  This specific triple depletion technique unmasked spots never visualized before. A total of 36 new spots were observed after depletion (348 vs 312 before depletion). Moreover, 58 spots showed more than twofold increase intensity after depletion. In the 60–69 kDa area, the depletion procedure unmasked 14 proteins including HSP70, LTA4H, L‐Plastin, Desmoplakin that are known to be involved in disease pathogenesis.

Conclusion:  The ability to selectively remove and elute the most abundant OF proteins visualized on the 2‐DE represents an important step in the characterization of human OF. The better visualization and gel resolution achieved will improve quantification abilities in 2‐DE and in tag‐MS leading to better identification of disease‐specific biomarkers. We further analyzed the eluted Alb and IgGs isoforms suggesting a new methodology venue for OF.
Responsible lending and borrowing: whereto low-cost home ownership?
Authors: Nield Sarah
Published: June 2010

The recent experience of the credit crunch has cast doubt on the prudence of regulation of the mortgage market based upon the concepts of responsible lending and borrowing. Both the Turner Review and the Financial Services Authority's follow-up Mortgage Market Review identified irresponsible lending as one of the principle causes of the credit crunch. Yet easy access to mortgage finance has underpinned the growth of owner occupation and the promotion of low-cost home ownership. This paper examines recent regulatory initiatives to articulate responsible lending and borrowing in more concrete terms, which suggests a shift towards greater lender responsibility through affordability checks, clearer product explanation and the possibility of product regulation. Whilst such proposals may assist in the pursuit of a more stable mortgage market, they cast serious doubt on the future sustainability of low-cost home ownership.
The use value of money in the law of unjust enrichment
Authors: Yip Man
Published: June 2010

In Sempra Metals Ltd v Inland Revenue Commissioners, the House of Lords, by a majority, recognised the right to recover compound interest for the ‘use value of money’, an independent benefit from the principal sum. This right is based in the principle of unjust enrichment. Nevertheless, the House of Lords could not agree on the proper understanding of ‘use value of money’ and left many important questions unaddressed which are crucial for paving the way forward for a claim for the ‘use value of money’. This paper will meet the following challenges – to justify the majority's position in Sempra Metals in recognising a right to compound interest for the ‘use value of money’; deal with the theoretical basis of ‘use value of money’; and recommend a model as the way forward for this newly recognised claim.
Temporal stability of photothermally fabricated micropatterns in supported phospholipid multilayers
Authors: Mathieu Mareike , Schunk Daniel , Franzka Steffen , Mayer Christian , Hartmann Nils
Published: June 2010

The temporal stability of photothermally fabricated micropatterns in multilayered films of 1,2-dioleoyl-sn-glycero-3-phosphate on surface-oxidized silicon substrates is investigated. Multilayered films are fabricated via spin coating of diluted phospholipid solutions. A focused beam of an Ar+ laser at λ=514nm and a 1∕e2 spot diameter of 2.5μm is used to locally remove the coating and fabricate micropatterns. Subsequently, the temporal stability of such patterns at ambient conditions in air and in water is examined using optical microscopy. Generally, these patterns are stable on a time scale of several hours to days, both in air and in water, and hence provide sufficient time for most follow-on experiments. The spin-coated phospholipid films, though, are intrinsically unstable in water. In particular, some hours after immersion in water, dewetting of the film starts to set in. The implications of these results for potential applications are discussed.