bluuebunny/crossref_metadata_2025 huggingface dataset:
Graded-mesh difference schemes for singularly perturbed two-point boundary value problems
Authors: Gartland Eugene C.
Published: June 2010

This paper is concerned with the numerical approximation by compact finite-difference schemes of differential operators of the form
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L Subscript epsilon Baseline u equals epsilon u Superscript left-parenthesis m right-parenthesis Baseline plus normal upper Sigma Subscript nu equals 0 Superscript m minus 1 Baseline a Subscript nu Baseline u Superscript left-parenthesis nu right-parenthesis">

L
ε

u
=
ε

u

(
m
)

+

Σ

ν
=
0

m
−
1

a
ν

u

(
ν
)

{L_\varepsilon }u = \varepsilon {u^{(m)}} + \Sigma _{\nu = 0}^{m - 1}{a_\nu }{u^{(\nu )}}

without turning points. The stability of

L
ε

{L_\varepsilon }

combined with various auxiliary conditions is discussed, and a representation result for solutions of problems involving it is proven. This representation decomposes the solution into a smooth outer component plus a decaying exponential layer term along the lines of the Method of Multiple Scales. The stability of compact difference analogues of

L
ε

{L_\varepsilon }

is studied, and a stability result is proven which generalizes earlier work. This result encompasses, for example, discretizations of second-order problems that fail to possess a maximum principle. It allows for standard polynomial-based differences in outer regions (away from boundary layers) with uniform meshes, even though such schemes admit oscillatory solutions. A family of finite-difference schemes based on an exponentially graded mesh and local polynomial basis functions is discussed. These schemes can be constructed to have arbitrarily high uniform order of convergence. To achieve a scheme of order

O
(

h
K

)

O({h^K})

, roughly K times as many points are distributed inside the layer as outside. The high order is achieved by using extra local evaluations of the coefficient functions and source term of the problem. A rigorous discretization error analysis of these schemes, using the established stability and representation results, is given. Numerical results exhibiting the performance of these schemes are presented and generalizations of the results in the paper are discussed.
A user-friendly extrapolation method for oscillatory infinite integrals
Authors: Sidi Avram
Published: June 2010

In a recent publication [4] the author developed an extrapolation method, the W-transformation, for the accurate computation of convergent oscillatory infinite integrals. In yet another publication [6] this method was shown to be applicable to divergent oscillatory infinite integrals that are defined in the sense of summability. The application of the W-transformation involves some asymptotic analysis of the integrand as the variable of integration tends to infinity. In the present work the W-transformation is modified so as to keep this asymptotic analysis to a minimum, involving only the phase of oscillations. This modified version, which turns out to be as efficient as the original W-transformation, can also be applied to convergent or divergent oscillatory infinite integrals other than those dealt with in [4] and [6]. The convergence properties of the modified transformation are analyzed in detail for the integrals of [4] and [6], and numerical examples are provided.
Essentially nonoscillatory spectral Fourier methods for shock wave calculations
Authors: Cai Wei , Gottlieb David , Shu Chi-Wang
Published: June 2010

In this paper, we present an essentially nonoscillatory spectral Fourier method for the solution of hyperbolic partial differential equations. The method is based on adding a nonsmooth function to the trigonometric polynomials which are the usual basis functions for the Fourier method. The high accuracy away from the shock is enhanced by using filters. Numerical results confirm that essentially no oscillations develop in the solution. Also, the accuracy of the spectral solution of the inviscid Burgers equation is shown to be higher than a fixed order.
Superconvergence for multistep collocation
Authors: Lie Ivar , Nørsett Syvert P.
Published: June 2010

One-step collocation methods are known to be a subclass of implicit Runge-Kutta methods. Further, one-leg methods are special multistep one-point collocation methods. In this paper we extend both of these collocation ideas to multistep collocation methods with k previous meshpoints and m collocation points. By construction, the order is at least

m
+
k
−
1

m + k - 1

. However, by choosing the collocation points in the right way, order

2
m
+
k
−
1

2m + k - 1

is obtained as the maximum. There are

(

m
+
k
−
1

k
−
1

)

\left ( {\begin {array}{*{20}{c}} {m + k - 1} \\ {k - 1} \\ \end {array} } \right )

sets of such "multistep Gaussian" collocation points.
Polynomial approximation of divergence-free functions
Authors: Sacchi Landriani Giovanni , Vandeven Hervé
Published: June 2010

We study the best approximation of a divergence-free function by a divergence-free algebraic or trigonometric polynomial and we prove an optimal estimate. In a particular case we give also an optimal result for the polynomial approximation of a function and its divergence.
Numerical results on relations between fundamental constants using a new algorithm
Authors: Bailey David H. , Ferguson Helaman R. P.
Published: June 2010

Let

x
=
(

x
1

,

x
2

,
…
,

x
n

)

x = ({x_1},{x_2}, \ldots ,{x_n})

be a vector of real numbers, x is said to possess an integer relation if there exist integers

a
i

{a_i}

not all zero such that

a
1

x
1

+

a
2

x
2

+
⋯
+

a
n

x
n

=
0

{a_1}{x_1} + {a_2}{x_2} + \cdots + {a_n}{x_n} = 0

. Beginning ten years ago, algorithms were discovered by one of us which, for any n, are guaranteed to either find a relation if one exists, or else establish bounds within which no relation can exist. One of those algorithms has been employed to study whether or not certain fundamental mathematical constants satisfy simple algebraic polynomials. Recently, one of us discovered a new relation-finding algorithm that is much more efficient, both in terms of run time and numerical precision. This algorithm has now been implemented on high-speed computers, using multiprecision arithmetic. With the help of these programs, several of the previous numerical results on mathematical constants have been extended, and other possible relationships between certain constants have been studied. This paper describes this new algorithm, summarizes the numerical results, and discusses other possible applications. In particular, it is established that none of the following constants satisfies a simple, low-degree polynomial:

γ
\gamma

(Euler’s constant),

log
⁡
γ

\log \gamma

,

log
⁡
π

\log \pi

,

ρ
1

{\rho _1}

(the imaginary part of the first zero of Riemann’s zeta function),

log
⁡

ρ
1

\log {\rho _1}

,

ζ
(
3
)

\zeta (3)

(Riemann’s zeta function evaluated at 3), and

log
⁡
ζ
(
3
)

\log \zeta (3)

. Several classes of possible additive and multiplicative relationships between these and related constants are ruled out. Results are also cited for Feigenbaum’s constant, derived from the theory of chaos, and two constants of fundamental physics, derived from experiment.
Computing all power integral bases of cubic fields
Authors: Gaál I. , Schulte N.
Published: June 2010

Applying Baker’s effective method and the reduction procedure of Baker and Davenport, we present several lists of solutions of index form equations in (totally real and complex) cubic algebraic number fields. These solutions yield all power integral bases of these fields.
TVB Runge-Kutta local projection discontinuous Galerkin finite element method for conservation laws. II. General framework
Authors: Cockburn Bernardo , Shu Chi-Wang
Published: June 2010

This is the second paper in a series in which we construct and analyze a class of TVB (total variation bounded) discontinuous Galerkin finite element methods for solving conservation laws

u
t

+

∑

i
=
1

d

(

f
i

(
u
)
)

x
i

=
0

{u_t} + \sum \nolimits _{i = 1}^d {{{({f_i}(u))}_{{x_i}}} = 0}

. In this paper we present a general framework of the methods, up to any order of formal accuracy, using scalar one-dimensional initial value and initial-boundary problems as models. In these cases we prove TVBM (total variation bounded in the means), TVB, and convergence of the schemes. Numerical results using these methods are also given. Extensions to systems and/or higher dimensions will appear in future papers.
The computational complexity of the resolution of plane curve singularities
Authors: Teitelbaum Jeremy
Published: June 2010

We present an algorithm which computes the resolution of a plane curve singularity at the origin defined by a power series with coefficients in a (not necessarily algebraically closed) field k of characteristic zero. We estimate the number of k-operations necessary to compute the resolution and the conductor ideal of the singularity. We show that the number of k-operations is polynomially bounded by the complexity of the singularity, as measured for example by the index of its conductor ideal. Our algorithm involves calculations over reduced rings with zero divisors, and employs methods of deformation theory to reduce the consideration of power series to the consideration of polynomials.
Best 𝐿²-approximation of convergent moment series
Authors: Baur Gerhard , Shawyer Bruce
Published: June 2010

The authors continue the investigation into the problem of finding the best approximation to the sum of a convergent series,

∑

n
=
0

∞

x
n

a
n

\sum \nolimits _{n = 0}^\infty {{x^n}{a_n}}

, where

{

a
n

}

\{ {a_n}\}

is a moment sequence. The case considered is where

x
=
1

x = 1

. This requires a proper subset of the set of all moment series. Instead of having
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="a Subscript n Baseline equals integral Subscript 0 Superscript 1 Baseline t Superscript n Baseline d phi left-parenthesis t right-parenthesis with integral Subscript 0 Superscript 1 Baseline StartAbsoluteValue d phi left-parenthesis t right-parenthesis EndAbsoluteValue equals 1 comma">

a
n

=

∫
0
1

t
n

d
ϕ
(
t
)

with

∫
0
1

|

d
ϕ
(
t
)

|

=
1
,

{a_n} = \int _0^1 {\,{t^n}\,d\phi (t)\quad {\text {with}}\quad } \int _0^1 {\,|d\phi (t)|} = 1,

\]
we have
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="a Subscript n Baseline equals integral Subscript 0 Superscript 1 Baseline t Superscript n Baseline left-parenthesis 1 minus t right-parenthesis Superscript delta Baseline psi left-parenthesis t right-parenthesis d t with integral Subscript 0 Superscript 1 Baseline StartAbsoluteValue psi left-parenthesis t right-parenthesis EndAbsoluteValue squared d t equals 1 period">

a
n

=

∫
0
1

t
n

(
1
−
t
)

δ

ψ
(
t
)

d
t

with

∫
0
1

|

ψ
(
t
)

|

2

d
t
=
1.

{a_n} = \int _0^1 {{\mkern 1mu} {t^n}{{(1 - t)}^\delta }\,\psi (t)\,dt\quad {\text {with}}\quad } \int _0^1 {{\mkern 1mu} |\psi (t){|^2}} \,dt = 1.

\]
With this subset, the authors find the best sequence-to-sequence transformation and show that the error in this transformation of

(
n
+
1
)

(n + 1)

terms of the series is
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartFraction 1 Over 2 delta StartRoot 2 delta minus 1 EndRoot EndFraction StartFraction n plus 1 Over StartBinomialOrMatrix n plus 2 delta Choose n EndBinomialOrMatrix EndFraction tilde StartFraction normal upper Gamma left-parenthesis 2 delta right-parenthesis Over StartRoot 2 delta minus 1 EndRoot EndFraction StartFraction 1 Over n Superscript 2 delta minus 1 Baseline EndFraction as n right-arrow normal infinity period">

1

2
δ

2
δ
−
1

n
+
1

(

n
+
2
δ

n

)

∼

Γ
(
2
δ
)

2
δ
−
1

1

n

2
δ
−
1

as

n
→
∞
.

\frac {1}{{2\delta \sqrt {2\delta - 1} }}\frac {{n + 1}}{{\left ( {\begin {array}{*{20}{c}} {n + 2\delta } \\ n \\ \end {array} } \right )}} \sim \frac {{\Gamma (2\delta )}}{{\sqrt {2\delta - 1} }}\frac {1}{{{n^{2\delta - 1}}}}\quad {\text {as}}\;n \to \infty .

\]
On the computation of 𝑔(𝑘) in Waring’s problem
Authors: Delmer Francine , Deshouillers Jean-Marc
Published: June 2010

Over two hundred years ago, Waring raised the question of representing natural integers as sums of integral kth powers. At the beginning of this century, Hilbert proved that, for any fixed k, the minimal number of summands needed in the representation of any integer can be uniformly bounded. The least such bound is denoted by

g
(
k
)

g(k)

. A first goal is to show that our knowledge of

g
(
k
)

g(k)

is rather satisfactory: —Writing down all the numbers

g
(
2
)
,
g
(
3
)
,
…
,
g
(
K
)

g(2),g(3), \ldots ,g(K)

may be performed in

O
(

K
2

)

O({K^2})

bit operations, which is best possible, since

g
(
k
)

g(k)

has

(
k
+
1
)

(k + 1)

digits in its binary expansion. —Writing down

g
(
k
)

g(k)

may be performed in

O
(
k
log
⁡
k
.
log
⁡
log
⁡
k
)

O(k\log k.\log \log k)

bit operations, which we expect to be fairly close to the actual complexity. A second aim is to discuss the complexity of checking the validity of the conjectured Diophantine inequality
\[

{

(
3

/

2

)
k

}
≤
1
−

(
3

/

4

)
k

;

\{ {(3/2)^k}\} \leq 1 - {(3/4)^k};

\]
the underlying idea has led J. M. Kubina and M. C. Wunderlich to check this up to 471,600,000. This inequality is related to Waring’s problem in that it would imply the formula
\[

g
(
k
)
=

2
k

+
[

(
3

/

2

)
k

]
−
2
;

g(k) = {2^k} + [{(3/2)^k}] - 2;

\]
however, the knowledge of this relation would not improve our knowledge on the complexity of computing

g
(
k
)

g(k)

, neither on average, nor for individual values of k.
Stability Configurations of Electrons on a Sphere
Authors: Goldberg Michael
Published: June 2010

Stable arrangements of electrons in equilibrium on the surface of a sphere have been obtained for most of the cases up to 14 electrons. They resemble the arrangements of the contact points of the faces of an

n
n

-hedron of least volume circumscribed about the sphere, except for

n
=
8

n = 8

. In this case, it is shown that the electrons near the contact points are in equilibrium, but the arrangement is not stable.
Checking atomicity of conformal ending measures for Kleinian groups
Authors: Falk Kurt , Matsuzaki Katsuhiko , Stratmann Bernd
Published: June 2010

In this paper we address questions of continuity and atomicity of conformal ending measures for arbitrary non-elementary Kleinian groups. We give sufficient conditions under which such ending measures are purely atomic. Moreover, we will show that if a conformal ending measure has an atom which is contained in the big horospherical limit set, then this atom has to be a parabolic fixed point. Also, we give detailed discussions of non-trivial examples for purely atomic as well as for non-atomic conformal ending measures.
ABC-SysBio—approximate Bayesian computation in Python with GPU support
Authors: Liepe Juliane , Barnes Chris , Cule Erika , Erguler Kamil , Kirk Paul , Toni Tina , Stumpf Michael P.H.
Published: June 2010

Motivation: The growing field of systems biology has driven demand for flexible tools to model and simulate biological systems. Two established problems in the modeling of biological processes are model selection and the estimation of associated parameters. A number of statistical approaches, both frequentist and Bayesian, have been proposed to answer these questions.

Results: Here we present a Python package, ABC-SysBio, that implements parameter inference and model selection for dynamical systems in an approximate Bayesian computation (ABC) framework. ABC-SysBio combines three algorithms: ABC rejection sampler, ABC SMC for parameter inference and ABC SMC for model selection. It is designed to work with models written in Systems Biology Markup Language (SBML). Deterministic and stochastic models can be analyzed in ABC-SysBio.

Availability:  http://abc-sysbio.sourceforge.net

Contact:  christopher.barnes@imperial.ac.uk; ttoni@imperial.ac.uk
RNA-Seq Analysis of Sulfur-Deprived Chlamydomonas Cells Reveals Aspects of Acclimation Critical for Cell Survival
Authors: González-Ballester David , Casero David , Cokus Shawn , Pellegrini Matteo , Merchant Sabeeha S. , Grossman Arthur R.
Published: June 2010

The Chlamydomonas reinhardtii transcriptome was characterized from nutrient-replete and sulfur-depleted wild-type and snrk2.1 mutant cells. This mutant is null for the regulatory Ser-Thr kinase SNRK2.1, which is required for acclimation of the alga to sulfur deprivation. The transcriptome analyses used microarray hybridization and RNA-seq technology. Quantitative RT-PCR evaluation of the results obtained by these techniques showed that RNA-seq reports a larger dynamic range of expression levels than do microarray hybridizations. Transcripts responsive to sulfur deprivation included those encoding proteins involved in sulfur acquisition and assimilation, synthesis of sulfur-containing metabolites, Cys degradation, and sulfur recycling. Furthermore, we noted potential modifications of cellular structures during sulfur deprivation, including the cell wall and complexes associated with the photosynthetic apparatus. Moreover, the data suggest that sulfur-deprived cells accumulate proteins with fewer sulfur-containing amino acids. Most of the sulfur deprivation responses are controlled by the SNRK2.1 protein kinase. The snrk2.1 mutant exhibits a set of unique responses during both sulfur-replete and sulfur-depleted conditions that are not observed in wild-type cells; the inability of this mutant to acclimate to S deprivation probably leads to elevated levels of singlet oxygen and severe oxidative stress, which ultimately causes cell death. The transcriptome results for wild-type and mutant cells strongly suggest the occurrence of massive changes in cellular physiology and metabolism as cells become depleted for sulfur and reveal aspects of acclimation that are likely critical for cell survival.
Sho1 and Msb2-Related Proteins Regulate Appressorium Development in the Smut Fungus Ustilago maydis
Authors: Lanver Daniel , Mendoza-Mendoza Artemio , Brachmann Andreas , Kahmann Regine
Published: June 2010

The dimorphic fungus Ustilago maydis switches from budding to hyphal growth on the plant surface. In response to hydrophobicity and hydroxy fatty acids, U. maydis develops infection structures called appressoria. Here, we report that, unlike in Saccharomyces cerevisiae and other fungi where Sho1 (synthetic high osmolarity sensitive) and Msb2 (multicopy suppressor of a budding defect) regulate stress responses and pseudohyphal growth, Sho1 and Msb2-like proteins play a key role during appressorium differentiation in U. maydis. Sho1 was identified through a two-hybrid screen as an interaction partner of the mitogen-activated protein (MAP) kinase Kpp6. Epistasis analysis revealed that sho1 and msb2 act upstream of the MAP kinases kpp2 and kpp6. Furthermore, Sho1 was shown to destabilize Kpp6 through direct interaction with the unique N-terminal domain in Kpp6, indicating a role of Sho1 in fine-tuning Kpp6 activity. Morphological differentiation in response to a hydrophobic surface was strongly attenuated in sho1 msb2 mutants, while hydroxy fatty acid–induced differentiation was unaffected. These data suggest that Sho1 and the transmembrane mucin Msb2 are involved in plant surface sensing in U. maydis.
Relationship between retinal sensitivity and morphologic changes in eyes with confluent soft drusen
Authors: Iwama Daisuke , Tsujikawa Akitaka , Ojima Yumiko , Nakanishi Hideo , Yamashiro Kenji , Tamura Hiroshi , Ooto Sotaro , Yoshimura Nagahisa
Published: June 2010

Abstract

Purpose:  To examine the relationship between retinal sensitivity and morphologic changes in the macular area of eyes with confluent soft drusen.

Methods:  We retrospectively reviewed the medical records of the 21 consecutive patients (22 eyes) who had confluent soft drusen in the macular area. Using spectral‐domain optical coherence tomography, a 6 × 6‐mm area of each macula was examined with 256 sequential horizontal scans. Microperimetry in the macular area was carried out using the Micro Perimeter 1.

Results:  Spectral‐domain optical coherence tomography images showed that protrusion of the retinal pigment epithelium (RPE) corresponded to the site of the confluent soft drusen. In addition, irregularities of the reflective line of the junction between inner and outer segments (IS/OS) of the photoreceptors were noted in 17 (77.3%) eyes. These irregularities were seen in the area with the protrusion of RPE. At 510 (68.1%) of 748 points with an intact retina, retinal sensitivity was 14 decibels or better. However, a retinal sensitivity of 14 decibels or better was obtained at 38.9% of points in irregular RPE with an intact IS/OS line, but at only 15.2% of points with an irregular IS/OS line. The mean retinal sensitivities within the area of irregular RPE with an intact IS/OS line, or in areas with an irregular IS/OS line, respectively, were significantly lower than that of intact retina (P < 0.0001).

Conclusion:  Eyes with confluent soft drusen often show focal areas with reduced retinal function, areas that are consistent with irregularity of the RPE or of the IS/OS line.
Hospital‐admitted eye injury in Victoria, Australia
Authors: Raymond Simon , Jenkins Mark , Favilla Ian , Rajeswaran Dylan
Published: June 2010

Abstract

Background:  The public health concern represented by eye injury in Victoria, Australia has been known for a period now approaching 20 years. However, there has been no improvement observed in this public health concern since it was first identified in the 1990s. This study further investigates the epidemiology of eye injury in Victoria, specifically hospital‐admitted eye injury.

Methods:  The Victorian Admitted Episodes Dataset was surveyed for eye injury coded by the International Classification of Diseases 10th revision during the period spanning 2001–2005, retrieving all cases of hospital‐admitted eye injury in Victoria during the surveyed period.

Results:  During the period surveyed, the average incidence of eye injury requiring hospital admission in Victoria was 53.6 per 100 000 person‐years. Sixty‐four per cent of patients were male and 36% were female (P < 0.001). Male patients were most commonly middle‐aged compared with female patients who were most commonly middle‐aged to elderly (P < 0.001). Core patient groups included: elderly women sustaining eye injuries as a result of falls (particularly in residential homes); middle‐aged men sustaining eye injuries as a result of assault and in transport‐related accidents.

Conclusion:  The incidence of hospital‐admitted eye injury in Victoria has increased since it was first identified as a concern in the 1990s. The design and implementation of an effective preventative strategy to reduce the rate of hospital‐admitted eye injury in Victoria presents as a difficult task given that the most common causes are represented by falls, assault and transport‐related accidents.
The Rising Tension between Shareholder and Director Power in the Common Law World
Authors: Hill Jennifer G.
Published: June 2010

Manuscript Type:Conceptual

Research Question/Issue:This article explores the rising tension between shareholder and director power in the common law world. First, the article analyzes key arguments in the shareholder empowerment debate, and current US reform proposals to grant shareholders stronger rights, from a comparative corporate law perspective, examining how traditional US legal rules diverge from other common law jurisdictions. Secondly, the article discusses power shifts in the opposite direction – namely toward the board – in some parts of the common law world. It considers the potential friction between legal rules designed to enhance shareholder power and commercial practices designed to subvert it.

Research Findings/Insights:The article shows that US shareholders have traditionally had unusually restricted rights compared to their counterparts in common law jurisdictions, such as the UK and Australia. The article challenges a number of arguments supporting this traditional US approach, by showing that the arguments are often US‐specific, and are less persuasive from a comparative corporate governance perspective. The article also identifies an important tension between legal rules designed to enhance shareholder power and commercial practices designed to subvert it. It shows how the dynamic nature of regulation, and the strategic response of regulated parties, can affect the operation of legal rules.

Theoretical/Academic Implications:The article broadens the scope of the US shareholder empowerment debate, by means of a comparative law analysis. It challenges an evolutionary/managerialist theory of US corporate governance, by showing that other jurisdictions have made different choices concerning the allocation of power between shareholders and the board. The article also shows the importance in comparative corporate governance scholarship of focusing not only on the terms of specific laws, but also on the commercial responses of parties subject to those laws.

Practitioner/Policy Implications:The article assesses the role of shareholder participation as a regulatory mechanism to enhance corporate governance legitimacy. The global financial crisis has highlighted some of the dangers of untramelled managerial power and under‐regulation. The article provides important regulatory insights to policy makers, concerning the appropriate balance of power between shareholders and the board of directors.
An anticancer strategic dilemma: to kill or to contain. The choice of the pharmaceutical industry in 2009
Authors: Perret Gérard‐Yves , Uzzan Bernard
Published: June 2010

For decades, the fight against cancer was based on oncolytic drugs aimed at eradicating malignant cells (killing strategy). The main flaws of this approach were its toxicity and the consequent emergence of resistance. New views on tumour biology consider tumours as complex organs involving dynamic interactions between their components. This implies the existence of dormant states and thus of a new therapeutic strategy aimed at inducing or extending tumour dormancy (containment strategy). The aim of this overview was to quantify the relative importance of these two strategies among the clinical trials (240 phase 1 and 186 phase 2 trials), launched or still in the pipeline and sponsored by the pharmaceutical industry in 2009. The most frequently targeted molecular entities are vascular endothelial growth factors (VEGFRs) (19 drugs), ErBBs (17 drugs), c‐met (14 drugs), tubulin (12 drugs), IGFRs (12 drugs). The main result of this overview is that the killing strategy is still largely prevailing since 326 drugs in 2009 (77% of the drugs tested in clinical trials in 2009) referred to this strategy, whereas 100 drugs could be attributed to the containment or mixed strategies in 2009. To obtain a dynamic view of the repartition of drugs between the killing strategy and the containment or mixed strategies, the present work should be renewed every 3–4 years.
Acute intravenous injection and short‐term oral administration of NG‐nitro‐l‐arginine methyl ester to the rat provoke increased pressor responses to agonists and hypertension, but not inhibition of acetylcholine‐induced hypotensive responses
Authors: López Ruth M. , Pérez Teresa , Castillo Carlos , Castillo María C. , Castillo Enrique F.
Published: June 2010

In experiments in vivo, we studied whether the endothelial dysfunction induced by nitric oxide (NO) synthesis inhibition is simultaneously or sequentially manifested as a reduced level of endothelium‐dependent agonist‐induced vasodilatation, an increased responsiveness to vasoconstrictors, and hypertension. Vascular responses to acetylcholine, phenylephrine, and angiotensin II were measured in pithed rats after acute intravenous injection (100 mg/kg) and short‐term oral administration of NG‐nitro‐l‐arginine methyl ester (l‐NAME; 60 mg/kg per day) for 1 and 3 days (l‐NAME1dandl‐NAME3d, respectively). Pithed rats were chosen because drug‐induced cardiovascular responses reflect only peripheral effects. Parallel experiments examined mean arterial pressure (MAP) values in anesthetized rats. After short‐terml‐NAME1dandl‐NAME3dtreatments, the MAP was significantly elevated in anesthetized but not pithed rats. Acute intravenous administration ofl‐NAME elevated MAP in pithed rats. Intravenous infusion of phenylephrine was used to compensate for the pressor response induced byl‐NAME in pithed animals. The maximum decrease and duration of the hypotensive responses to acetylcholine were unaltered by the acute and both short‐terml‐NAME treatments in pithed rats. These treatments, on the other hand, increased phenylephrine‐ and angiotensin II‐induced pressor responses in pithed animals. In isolated aortic rings prepared from pithed rats treated acutely and short‐term withl‐NAME, acetylcholine‐induced relaxations were inhibited. Thus, the inhibition of NO‐dependent vasodilator tone after acute intravenous injection and short‐term orall‐NAME administration may be associated with vascular smooth muscle hyper‐responsiveness to pressor agonists and hypertension, whereas the hypotensive responses to acetylcholine could not be associated with thel‐NAME‐induced endothelial dysfunction in pithed rats.
Level of evidence for therapeutic drug monitoring for etoposide after oral administration
Authors: Gerritsen‐van Schieveen Pauline , Royer Bernard ,   ‘Therapeutic drug monitoring group of the French Society of Pharmacology and Therapeutics’
Published: June 2010

Oral etoposide displays high intervariability and intravariability. Convincing relationships were observed between hematological toxicities and exposure of which total etoposide area under the curve seems the more relevant in routine practice. Linear pharmacokinetics, limited sampling strategies and reduction in variability during concentration‐controlled studies argue in favor of therapeutic drug monitoring. However, such reduction in variability should be confirmed after oral administration. For these reasons, such practice can be considered as ‘potentially useful’. Further studies using Bayesian approach are nevertheless needed to definitely state regarding the level of evidence therapeutic drug monitoring of oral etoposide.
Operations research/management science tools for integrating people with disabilities into employment. A study on Valencia's Sheltered Work Centres for Disabled
Authors: Miralles Cristóbal , Marin‐Garcia Juan A. , Ferrus Gabriel , Costa Alysson M.
Published: June 2010

People with disabilities have a right to a full life in every sense and one of those fundamental rights is the possibility to work. In this paper, the importance of social employment integration of disabled people is highlighted as one of the stakeholders to be satisfied by companies in the new framework that corporate social responsibility is constructing. The objective of the paper is to revise the benefits of some well‐known operations research/management science tools that, if applied correctly, have a double positive impact on work accessibility and improved productivity. The responses collected from managers of Valencia's Sheltered Work Centres for Disabled by means of a structured questionnaire are used to analyse the level of implementation of these tools and their impact depending on the type of centre, the kind of disability and other structural variables.
Design and Results of an Intensive Monitoring Programme for Avian Influenza in Meat‐Type Turkey Flocks During Four Epidemics in Northern Italy
Authors: Comin A. , Stegeman J. A. , Klinkenberg D. , Busani L. , Marangon S.
Published: June 2010

Surveillance programmes for low pathogenicity (LPAI) and high pathogenicity avian influenza (HPAI) infections in poultry are compulsory for EU Member States; yet, these programmes have rarely been evaluated. In Italy, following a 1999 HPAI epidemic, control measures, including vaccination and monitoring, were implemented in the densely populated poultry area (DPPA) where all epidemics in Italy have been concentrated. We evaluated the monitoring system for its capacity to detect outbreaks rapidly in meat‐type turkey flocks. The evaluation was performed in vaccination areas and high‐risk areas in the DPPA, in 2000–2005, during which four epidemics occurred. Serum samples and cloacal swabs were taken from vaccinated birds and unvaccinated (sentinel) birds. We compared the detection rate of active, passive and targeted surveillance, by vaccination status, using multinomial logistic regression. A total of 13 275 samplings for serological testing and 4889 samplings for virological testing were performed; 6315 production cycles of different bird species were tested. The outbreaks detection rate in meat‐type turkeys was 61% for active surveillance (n = 222/363 outbreaks), 32% for passive surveillance and 7% for targeted surveillance. The maximum likelihood predicted values for the detection rates differed by vaccination status: in unvaccinated flocks, it was 50% for active surveillance, 40% for passive surveillance and 10% for targeted surveillance, compared to respectively 79%, 17% and 4% for vaccinated flocks. Active surveillance seems to be most effective in detecting infection, especially when a vaccination programme is in place. This is the first evaluation of the effectiveness of different types of surveillance in monitoring LPAI infections in vaccinated poultry using field data.
Schottky metal-GaN interface KOH pretreatment for improved device performance
Authors: Shah P. B. , Batyrev I. , Derenge M. A. , Lee U. , Nyguen C. , Jones K. A.
Published: June 2010

The effect of KOH pretreatment for Au/Ni Schottky contacts to GaN is investigated using I-V and x-ray photoemission spectroscopy (XPS) analysis. The molten KOH pretreatment reduces the interface trap density from 1.0×1012 to 2×1011 cm−2 eV−1, improves the on-state performance, and increases the barrier height by 10%. XPS indicates that KOH improves the GaN Schottky diode performance by eliminating an oxide layer between the metal and the semiconductor, increasing the band bending through charge transfer, and improving the GaN stoichiometry at the surface. First principle simulations indicate that the nitrogen antisite and to a minor extent the gallium antisite are also possible constituents of this interfacial layer along with gallium and nitrogen vacancies. These antisite defects can be passivated by KOH.
Microstructure and corrosion resistance of nanocrystalline TiZrN films on AISI 304 stainless steel substrate
Authors: Lin Yu-Wei , Huang Jia-Hong , Yu Ge-Ping
Published: June 2010

This study investigated the microstructure and properties of nanocrystalline TiZrN films on AISI 304 stainless steel substrate. TiZrN films were prepared by reactive magnetron sputtering based on the previous optimum coating conditions (substrate temperature, system pressure, nitrogen flow, etc.) for TiN and ZrN thin films. The composition ratio of TiZrN coatings were adjusted by changing the Zr target power, while keeping the Ti target power constant. Experiments were conduced to find the optimum composition with desired properties. The ratio of TiZrN composition was analyzed by x-ray photoelectron spectroscopy and Rutherford backscattering spectrometer. In terms of phase formation, there were two types of coatings that were considered: single-phase solid solutions of TiZrN and interlacing nuclei of TiZr in the matrix of TiZrN. The thickness of all TiZrN films as measured by the secondary ion mass spectroscopy was about 500 nm, and the composition depth profiles indicated that the compositions in the TiZrN films were uniform from the film surface to the 304 stainless steel substrate. The crystal structure of the TiZrN films was determined by x-ray diffraction using a M18XHF-SRA diffractometer with Cu Kα radiation. A diffraction peak of TiZrN (002) was observed between that of TiN (002) and ZrN (002); similarly, a diffraction peak of TiZrN (111) was observed between that of TiN(111) and ZrN(111), respectively. The corrosion resistance of the TiZrN film deposited on the 304 stainless steel has been investigated by electrochemical measurement. The electrolyte, 0.5M H2SO4 containing 0.05M KSCN, was used for the potentiodynamic polarization. The potentiodynamic scan was conducted from −800 to 800 mV standard calomel electrode (SCE).
Effect of surface material and roughness on conductance of channel between parallel disks at molecular flow
Authors: Yoshida Hajime , Shiro Masanori , Arai Kenta , Hirata Masahiro , Akimichi Hitoshi
Published: June 2010

The effect of surface material and roughness on the conductance of a channel at molecular flow was measured for N2, Ar, He, and H2. The experimental results were compared with the results of Monte Carlo calculations. The channel consisted of two parallel disks with different surfaces including polished stainless steel (SS), roughly polished SS, quartz, Ti, Cu, Al, alumina with smooth surface, alumina with rough surface, Au coating, Pt coating, and diamondlike carbon (DLC) coating. The conductances of the experimental channel depended on the slope of the surface roughness, rather than the arithmetic surface roughness (Ra) or the material. In the case of smooth surfaces, such as polished SS, quartz, and DLC coating, the experimental results for N2, Ar, and H2 show good agreement with the calculation, assuming diffuse reflection. The momentum accommodation coefficients on these surfaces for N2, Ar, and H2 were estimated to be in the range from 0.98 to 1.00, based on the assumption that specular reflection was simply included in diffuse reflection. The conductance for He, however, was 3%–5% larger than that of the calculation. The momentum accommodation coefficient for He was similarly estimated to be in the range from 0.95 to 0.97.
Tungsten oxide (WO3) thin films for application in advanced energy systems
Authors: Gullapalli S. K. , Vemuri R. S. , Manciu F. S. , Enriquez J. L. , Ramana C. V.
Published: June 2010

Inherent processes in coal gasification plants produce hazardous hydrogen sulfide (H2S), which must be continuously and efficiently detected and removed before the fuel is used for power generation. An attempt has been made in this work to fabricate tungsten oxide (WO3) thin films by radio-frequency reactive magnetron-sputter deposition. The impetus being the use of WO3 films for H2S sensors in coal gasification plants. The effect of growth temperature, which is varied in the range of 30–500 °C, on the growth and microstructure of WO3 thin films is investigated. Characterizations made using scanning electron microscopy (SEM) and x-ray diffraction (XRD) indicate that the effect of temperature is significant on the microstructure of WO3 films. XRD and SEM results indicate that the WO3 films grown at room temperature are amorphous, whereas films grown at higher temperatures are nanocrystalline. The average grain-size increases with increasing temperature. WO3 films exhibit smooth morphology at growth temperatures ≤300 °C while relatively rough at >300 °C. The analyses indicate that the nanocrystalline WO3 films grown at 100–300 °C could be the potential candidates for H2S sensor development for application in coal gasification systems.
Direct simulation Monte Carlo modeling of e-beam metal deposition
Authors: Venkattraman A. , Alexeenko A. A.
Published: June 2010

Three-dimensional direct simulation Monte Carlo (DSMC) method is applied here to model the electron-beam physical vapor deposition of copper thin films. Various molecular models for copper-copper interactions have been considered and a suitable molecular model has been determined based on comparisons of dimensional mass fluxes obtained from simulations and previous experiments. The variable hard sphere model that is determined for atomic copper vapor can be used in DSMC simulations for design and analysis of vacuum deposition systems, allowing for accurate prediction of growth rates, uniformity, and microstructure.
Effects of deposition and annealing temperatures on the electrical and optical properties of Ag2O and Cu2O–Ag2O thin films
Authors: Tseng C. C. , Hsieh J. H. , Lin C. H. , Wu W.
Published: June 2010

Ag 2 O and Ag2O–Cu2O films were deposited on glass substrates by magnetron sputtering of Ag and Cu targets at various substrate temperatures. After deposition, some of these films were annealed using a rapid thermal annealing system, with the variation of temperature. An UV-VIS-NIR photometer and a Hall measurement system were used to characterize the optical and electrical properties of these films. On annealing, Ag2O (hexagonal) phase would slowly change to Ag+Ag2O (cubic) phases when the annealing temperature is greater than 200 °C. When the annealing temperature was higher than 450 °C, the Ag2O phase would transform into a metallic Ag phase completely. Accordingly, the band gap of these films will change, along with the optical and electrical properties. In the study of Ag2O–Cu2O films, it is found that these two-phase composite films could exist obviously when deposited at room temperature. The photoinduced current of these composite films could be increased significantly, compared with that of a single Cu2O phase. This is most likely due to that a large band gap semiconductor (Cu2O) is coupled with a small band gap semiconductor (Ag2O).
Infinitely high selective inductively coupled plasma etching of an indium tin oxide binary mask structure for extreme ultraviolet lithography
Authors: Park Y. R. , Ahn J. H. , Kim J. S. , Kwon B. S. , Lee N.-E. , Kang H. Y. , Hwangbo C. K. , Ahn Jinho , Seo Hwan Seok
Published: June 2010

Currently, extreme ultraviolet lithography (EUVL) is being investigated for next generation lithography. Among the core EUVL technologies, mask fabrication is of considerable importance due to the use of new reflective optics with a completely different configuration than those of conventional photolithography. This study investigated the etching properties of indium tin oxide (ITO) binary mask materials for EUVL, such as ITO (absorber layer), Ru (capping/etch-stop layer), and a Mo–Si multilayer (reflective layer), by varying the Cl2/Ar gas flow ratio, dc self-bias voltage (Vdc), and etch time in inductively coupled plasmas. The ITO absorber layer needs to be etched with no loss in the Ru layer on the Mo–Si multilayer for fabrication of the EUVL ITO binary mask structure proposed here. The ITO layer could be etched with an infinitely high etch selectivity over the Ru etch-stop layer in Cl2/Ar plasma even with a very high overetch time.
Magnetic tunnel junctions with Co-based perpendicular magnetic anisotropy multilayers
Authors: Tadisina Z. R. , Natarajarathinam A. , Gupta S.
Published: June 2010

Magnetic CoFeB/MgO/CoFeB-based tunnel junctions with perpendicular magnetic anisotropy Co/M multilayers (M=Ni, Pd, Pt) have been investigated as a function of structural and magnetic properties. Magnetometry, ferromagnetic resonance, x-ray diffraction, stress tests, and local electrode atom probe tomography were carried out primarily on Co/Ni multilayers. A statistical design of experiments was conducted to optimize the perpendicular magnetic anisotropy and damping parameter α of these multilayers. Seed layers, thickness, and thickness ratios are all critical to achieve perpendicular behavior. Perpendicular MgO-based magnetic tunnel junctions with Co/Ni and Co/Pd reference and free layers were fabricated and tested. Sharp MR-H switching characteristics were observed for the Co/Pd multilayers, and a somewhat softer transition was observed for the Co/Ni multilayer with a Cu seed, which did not have as high a perpendicular anisotropy. Tunneling magnetoresistance (TMR) values were limited to about 10%, primarily because the fcc-bcc-fcc transition does not promote the “MgO giant TMR” symmetry filtering effect.
In situ analyses on negative ions in the sputtering process to deposit Al-doped ZnO films
Authors: Tsukamoto Naoki , Watanabe Daisuke , Saito Motoaki , Sato Yasushi , Oka Nobuto , Shigesato Yuzo
Published: June 2010

The origin of high energy negative ions during deposition of aluminum doped zinc oxide (AZO) films by dc magnetron sputtering of an AZO (Al2O3: 2.0 wt %) target was investigated by in situ analyses using the quadrupole mass spectrometer combined with the electrostatic energy analyzer. High energy negative oxygen (O−) ions which possessed the kinetic energy corresponding to the cathode sheath voltage were detected. The maximum flux of the O− ions was clearly observed at the location opposite to the erosion track area on the target. The flux of the O− ions changed hardly with increasing O2 flow ratio [O2/(Ar+O2)] from 0% to 5%. The kinetic energy of the O− ions decreased with decreasing cathode sheath voltage from 403 to 337 V due to the enhancement of the vertical maximum magnetic field strength at the cathode surface from 0.025 to 0.100 T. The AZO films deposited with the lower O− bombardment energy showed the higher crystallinity and improved the electrical conductivity.
Ge doped HfO2 thin films investigated by x-ray absorption spectroscopy
Authors: Miotti Leonardo , Bastos Karen P. , Lucovsky Gerald , Radtke Cláudio , Nordlund Dennis
Published: June 2010

The stability of the tetragonal phase of Ge doped HfO2 thin films on Si(100) was investigated. Hf(Ge)O2 films with Ge atomic concentrations varying from 0% to 15% were deposited by remote plasma chemical vapor deposition. The atomic structure on the oxide after rapid thermal annealing was investigated by x-ray absorption spectroscopy of the O and Ge K edges and by Rutherford backscattering spectrometry. The authors found that Ge concentrations as low as 5 at. % effectively stabilize the tetragonal phase of 5 nm thick Hf(Ge)O2 on Si and that higher concentrations are not stable to rapid thermal annealing at temperatures above 750 °C.
Electrical resistivity change in Al:ZnO thin films dynamically deposited by bipolar pulsed direct-current sputtering and a remote plasma source
Authors: Yang Wonkyun , Joo Junghoon
Published: June 2010

The Al-doped ZnO (AZO) thin films for a transparent conducting oxide in solar cell devices were deposited by bipolar pulsed dc magnetron sputtering. This work was performed in an in-line type system and investigated AZO films in a static deposition mode and dynamic one, which is more important in the practical fields. Because of this dynamic deposition process, the zigzagged columnar structure was observed. This resulted in the decreasing electrical property, optical properties, and surface roughness. As a deposition in the dynamic mode, the resistivity increased from 1.64×10−3 to 2.50×10−3 Ω cm, as compared to that in the static mode, and the transmittance also decreased from 83.9% to 78.3%. To recover the disadvantage, a remote plasma source (RPS) was supported between the substrate and target for reducing zigzagged formation during the deposition. The deposition rate decreased by using RPS, but the electrical and optical properties of films got better than only dynamic mode. The resistivity and transmittance in the dynamic mode using RPS were 2.1×10−3 Ω cm and 85.5%, respectively. In this study, the authors found the possibility to advance the electrical and optical properties of AZO thin films in the industry mode.