bluuebunny/crossref_metadata_2025 huggingface dataset:
Interpolation by multivariate splines
Authors: Chui Charles K. , Diamond Harvey , Raphael Louise A.
Published: June 2010

A general interpolation scheme by multivariate splines at regular sample points is introduced. This scheme guarantees the local optimal order of approximation to sufficiently smooth data functions. A discussion on numerical implementation is included.
Convergence results for piecewise linear quadratures for Cauchy principal value integrals
Authors: Rabinowitz Philip
Published: June 2010

Conditions on k and f are given for the pointwise and uniform convergence to the Cauchy principal value integral
\[

∫

k
(
x
)
f
(
x
)

x
−
λ

d
x

,

−
1
>
λ
>
1
,

\int {\frac {{k(x)f(x)}}{{x - \lambda }}\,dx} ,\quad - 1 > \lambda > 1,

\]
of a sequence of integrals of piecewise linear approximations to

f
(
x
)

f(x)

or
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="g Subscript lamda Baseline left-parenthesis x right-parenthesis equals left-parenthesis f left-parenthesis x right-parenthesis equals f left-parenthesis lamda right-parenthesis right-parenthesis slash left-parenthesis x minus lamda right-parenthesis">

g
λ

(
x
)
=
(
f
(
x
)
=
f
(
λ
)
)

/

(
x
−
λ
)

{g_\lambda }(x) = (f(x) = f(\lambda ))/(x - \lambda )

. The important special case,

k
(
x
)
=

(
1
−
x

)
α

(
1
+
x

)
β

k(x) = {(1 - x)^\alpha }{(1 + x)^\beta }

, is considered in detail.
On the number of elliptic pseudoprimes
Authors: Gordon Daniel M.
Published: June 2010

For an elliptic curveEwith complex multiplication by an order inK=Q(−d)K = {\mathbf {Q}}(\sqrt { - d} ), a pointPof infinite order onE, and any primepwith(−d|p)=−1( - d|p) = - 1, we have that(p+1)⋅P=O(modp)(p + 1) \cdot P = O\pmod p, whereOis the point at infinity and calculations are done using the addition law forE. Any composite number which satisfies these conditions is called an elliptic pseudoprime. In this paper it is shown that, assuming the Generalized Riemann Hypothesis, elliptic pseudoprimes are less numerous than primes. In particular, on the GRH, the number of elliptic pseudoprimes less thanxisO(xlog⁡log⁡x/log2x)O(x\log \log x/{\log ^2}x). For certain curves it is shown that infinitely many elliptic pseudoprimes exist.
Scattering by a potential using hyperbolic methods
Authors: Bayliss Alvin , Li Yan Yan , Morawetz Cathleen Synge
Published: June 2010

This is a preliminary note on a numerical time-dependent approach to the inverse scattering problem where the data given is back scattering. The results in one space variable are both computed and are quite comparable to the best existing results. A corresponding algorithm is developed for two variables. A major stage is the computation of the forward problem for the wave equation with potential and with an incoming plane wave. Interesting developments are a boundary layer next to the propagating delta function and effective resolution of the scattered wave. It is assumed there are no bound states.
A new lower bound for odd perfect numbers
Authors: Brent Richard P. , Cohen Graeme L.
Published: June 2010

We describe an algorithm for proving that there is no odd perfect number less than a given bound K (or finding such a number if one exists). A program implementing the algorithm has been run successfully with

K
=

10

160

K = {10^{160}}

, with an elliptic curve method used for the vast number of factorizations required.
Procedures for estimating the error in Padé approximation
Authors: Brezinski Claude
Published: June 2010

Kronrod’s procedure is a method for estimating the error in Gaussian quadrature methods. Padé approximants are formal Gaussian quadrature formulas. In a previous paper, Kronrod’s method was used to obtain estimates of the error in Padé approximation. Using a new interpretation of this procedure and three different expressions of the error of Padé approximants, extensions of the method are obtained. They provide new error estimates for Padé approximants. These estimates are compared.
Convergence of a shock-capturing streamline diffusion finite element method for a scalar conservation law in two space dimensions
Authors: Szepessy Anders
Published: June 2010

We prove a convergence result for a shock-capturing streamline diffusion finite element method applied to a time-dependent scalar nonlinear hyperbolic conservation law in two space dimensions. The proof is based on a uniqueness result for measure-valued solutions by DiPerna. We also prove an almost optimal error estimate for a linearized conservation law having a smooth exact solution.
A stable extrapolation method for multidimensional degenerate parabolic problems
Authors: Nochetto Ricardo H.
Published: June 2010

Degenerate parabolic problems in several space variables are approximated by combining a preliminary regularization procedure with a finite element extrapolation method. The proposed extrapolation acts on the so-called phase variable and leads to a linear problem which is shown to be stable. The ensuing linear algebraic system involves the same matrix for all time steps. Energy error estimates are also derived for the physical unknowns. An

O
(

h

1

/

2

)

O({h^{1/2}})

rate of convergence is proved, provided the approximation parameters are suitably related. In case the linear systems are solved by an iterative algorithm, such as the conjugate gradient method, an

O
(

h

3

/

2

)

O({h^{3/2}})

tolerance for the error reduction is shown to preserve the overall accuracy; the required computational effort is thus nearly optimal.
Quadratic convergence of vortex methods
Authors: Del Prete Vincenza
Published: June 2010

We prove quadratic convergence for two-dimensional vortex methods with positive cutoffs. The result is established for flows with initial vorticity three times continuously differentiable and compact support. The proof is based on a refined version of a convergence result.
Fermat’s last theorem (case 1) and the Wieferich criterion
Authors: Coppersmith Don
Published: June 2010

This note continues work by the Lehmers [3], Gunderson [2], Granville and Monagan [1], and Tanner and Wagstaff [6], producing lower bounds for the prime exponent p in any counterexample to the first case of Fermat’s Last Theorem. We improve the estimate of the number of residues

r
mod

p
2

r\bmod {p^2}

such that

r
p

≡
r
mod

p
2

{r^p} \equiv r\bmod {p^2}

, and thereby improve the lower bound on p to

7.568
×

10

17

7.568 \times {10^{17}}

.
Figures of merit for digital multistep pseudorandom numbers
Authors: André Debra A. , Mullen Gary L. , Niederreiter Harald
Published: June 2010

The statistical independence properties of s successive digital multistep pseudorandom numbers are governed by the figure of merit

ρ

(
s
)

(
f
)

{\rho ^{(s)}}(f)

which depends on s and the characteristic polynomial f of the recursion used in the generation procedure. We extend previous work for s = 2 and describe how to obtain large figures of merit for

s
>
2

s > 2

, thus arriving at digital multistep pseudorandom numbers with attractive statistical independence properties. Tables of figures of merit for

s
=
3
,
4
,
5

s = 3,4,5

and degrees

≤
32

\leq 32

are included.
Factoring multivariate polynomials over large finite fields
Authors: Wan Da Qing
Published: June 2010

A simple probabilistic algorithm is presented to find the irreducible factors of a bivariate polynomial over a large finite field. For a polynomial

f
(
x
,
y
)

f(x,y)

over

F
q

{F_q}

of total degree n, our algorithm takes at most
\[

n

4.89

log
2

n
log
⁡
q

{n^{4.89}}{\log ^2}n\log q

\]
operations in

F
q

{F_q}

to factor

f
(
x
,
y
)

f(x,y)

completely. This improves a probabilistic factorization algorithm of von zur Gathen and Kaltofen, which takes
\[

O
(

n

11

log
⁡
n
log
⁡
q
)

O({n^{11}}\log n\log q)

\]
operations to factor

f
(
x
,
y
)

f(x,y)

completely over

F
q

{F_q}

. The algorithm can be easily generalized to factor multivariate polynomials over finite fields. We shall give two further applications of the idea involved in the algorithm. One is concerned with exponential sums; the other is related to permutational polynomials over finite fields (a conjecture of Chowla and Zassenhaus).
Computer use in continued fraction expansions
Authors: Frank Evelyn
Published: June 2010

In this study, the use of computers is demonstrated for the rapid expansion of a general regular continued fraction with rational elements for

√
C
+
L

\surd C + L

, where

C
C

and

L
L

are rational numbers,

C
C

positive. Formulas for the expansion are derived. Conditions for the periodicity are considered. A Fortran program for the algorithms is given, as well as sample continued fraction expansions. Up to the present, practically all studies have been concerned with continued fractions with partial numerators

±
1

\pm 1

and partial denominators positive integers, due to difficulties in calculation. But now the use of computers makes possible the study of a much greater variety of continued fraction expansions.
A closed form evaluation of the elliptic integral
Authors: Glasser M. L. , Wood V. E.
Published: June 2010

The complete elliptic integral of the first kind

K
(
k
)

K(k)

is evaluated in terms of gamma functions for the moduli

k
=
√
2
−
1

k = \surd 2 - 1

and

(
2
√
2
−
2

)

1

/

2

{(2\surd 2 - 2)^{1/2}}

.
An elliptic integral identity
Authors: Glasser M. L.
Published: June 2010

The definite integral
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="integral Subscript 0 Superscript normal infinity Baseline left-bracket StartFraction left-parenthesis x squared plus a squared right-parenthesis Superscript 1 slash 2 Baseline minus a Over x squared plus a squared EndFraction right-bracket Superscript 1 slash 2 Baseline upper K left-bracket StartFraction left-parenthesis x squared plus b squared right-parenthesis Superscript 1 slash 2 Baseline minus b Over left-parenthesis x squared plus b squared right-parenthesis Superscript 1 slash 2 Baseline plus b EndFraction right-bracket StartFraction d x Over left-parenthesis x squared plus b squared right-parenthesis Superscript 1 slash 2 Baseline plus b EndFraction">

∫
0
∞

[

(

x
2

+

a
2

)

1

/

2

−
a

x
2

+

a
2

]

1

/

2

K

[

(

x
2

+

b
2

)

1

/

2

−
b

(

x
2

+

b
2

)

1

/

2

+
b

]

d
x

(

x
2

+

b
2

)

1

/

2

+
b

{\int _0^\infty {\left [ {\frac {{{{({x^2} + {a^2})}^{1/2}} - a}}{{{x^2} + {a^2}}}} \right ]} ^{1/2}}K\left [ {\frac {{{{({x^2} + {b^2})}^{1/2}} - b}}{{{{({x^2} + {b^2})}^{1/2}} + b}}} \right ]\frac {{dx}}{{{{({x^2} + {b^2})}^{1/2}} + b}}

\]
is evaluated in closed form.
Phenoclustering: online mining of cross-species phenotypes
Authors: Groth Philip , Kalev Ivan , Kirov Ivaylo , Traikov Borislav , Leser Ulf , Weiss Bertram
Published: June 2010

Summary: Recently, several methods for analyzing phenotype data have been published, but only few are able to cope with data sets generated in different studies, with different methods, or for different species. We developed an online system in which more than 300 000 phenotypes from a wide variety of sources and screening methods can be analyzed together. Clusters of similar phenotypes are visualized as networks of highly similar phenotypes, inducing gene groups useful for functional analysis. This system is part of PhenomicDB, providing the world's largest cross-species phenotype data collection with a tool to mine its wealth of information.

Availability: Freely available at http://www.phenomicdb.de

Contact:  bertram.weiss@bayerhealthcare.com

Supplementary information:  Supplementary data are available at Bioinformatics online.
Assemble: an interactive graphical tool to analyze and build RNA architectures at the 2D and 3D levels
Authors: Jossinet Fabrice , Ludwig Thomas E. , Westhof Eric
Published: June 2010

Summary: Assemble is an intuitive graphical interface to analyze, manipulate and build complex 3D RNA architectures. It provides several advanced and unique features within the framework of a semi-automated modeling process that can be performed by homology and ab initio with or without electron density maps. Those include the interactive editing of a secondary structure and a searchable, embedded library of annotated tertiary structures. Assemble helps users with performing recurrent and otherwise tedious tasks in structural RNA research.

Availability and Implementation: Assemble is released under an open-source license (MIT license) and is freely available at http://bioinformatics.org/assemble. It is implemented in the Java language and runs on MacOSX, Linux and Windows operating systems.

Contact:  f.jossinet@ibmc-cnrs.unistra.fr
CplexA: a Mathematica package to study macromolecular-assembly control of gene expression
Authors: Vilar Jose M.G. , Saiz Leonor
Published: June 2010

Summary: Macromolecular assembly coordinates essential cellular processes, such as gene regulation and signal transduction. A major challenge for conventional computational methods to study these processes is tackling the exponential increase of the number of configurational states with the number of components. CplexA is a Mathematica package that uses functional programming to efficiently compute probabilities and average properties over such exponentially large number of states from the energetics of the interactions. The package is particularly suited to study gene expression at complex promoters controlled by multiple, local and distal, DNA binding sites for transcription factors.

Availability: CplexA is freely available together with documentation at http://sourceforge.net/projects/cplexa/

Contact:  j.vilar@ikerbasque.org; lsaiz@ucdavis.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Deriving the consequences of genomic variants with the Ensembl API and SNP Effect Predictor
Authors: McLaren William , Pritchard Bethan , Rios Daniel , Chen Yuan , Flicek Paul , Cunningham Fiona
Published: June 2010

Summary: A tool to predict the effect that newly discovered genomic variants have on known transcripts is indispensible in prioritizing and categorizing such variants. In Ensembl, a web-based tool (the SNP Effect Predictor) and API interface can now functionally annotate variants in all Ensembl and Ensembl Genomes supported species.

Availability: The Ensembl SNP Effect Predictor can be accessed via the Ensembl website at http://www.ensembl.org/. The Ensembl API (http://www.ensembl.org/info/docs/api/api_installation.html for installation instructions) is open source software.

Contact:  wm2@ebi.ac.uk; fiona@ebi.ac.uk

Supplementary information:  Supplementary data are available at Bioinformatics online.
Transthoracic bioimpedance and brain natriuretic peptide levels accurately indicate additional diastolic dysfunction in patients with chronic advanced systolic heart failure
Authors: Malfatto Gabriella , Branzi Giovanna , Giglio Alessia , Villani Alessandra , Facchini Camilla , Ciambellotti Francesca , Facchini Mario , Parati Gianfranco
Published: June 2010

Aims

Diastolic dysfunction in patients with heart failure has prognostic relevance, possibly because of its relationship with worsening haemodynamic status. In the quest for simpler indexes of haemodynamic status in patients, brain natriuretic peptide (BNP) levels have been proposed as a surrogate of diastolic function. To date, the value of combining BNP levels with non‐invasive haemodynamic monitoring by transthoracic electric bioimpedance (TEB) for the prediction of diastolic function has not been evaluated.

Methods and results

We compared left ventricular diastolic function measured by tissue Doppler imaging (TDI) with TEB results and BNP levels in 120 patients with chronic advanced systolic heart failure on optimal treatment (70 ± 9 years, NYHA 2.4 ± 0.8, ejection fraction 31 ± 5%). Of the TEB variables measured, we only considered thoracic fluid content (TFC). To describe diastolic function, we used the TDI of the velocity of displacement of the mitral annulus (E′) and the ratio E/E′. In all patients, E/E′ was significantly related to TFC and to BNP levels (P < 0.001). Moreover, the combination of BNP ≥ 350 pg/mL and TFC ≥ 35/kΩ identified patients with diastolic dysfunction (defined as E/E′ ≥ 15) with high sensitivity and specificity (95 and 94%, respectively).

Conclusion

The combination of transthoracic bioimpedance monitoring and BNP measurement accurately indicated the presence of diastolic dysfunction in most patients. These user‐friendly and operator‐independent tools may be useful as a screening assessment for diastolic dysfunction, and consequently abnormal central haemodynamic status, either in ambulatory patients or when an adequate echocardiographic evaluation is not readily available.
MoMAR-D: a technological challenge to monitor the dynamics of the Lucky Strike vent ecosystem
Authors: Colaço A. , Blandin J. , Cannat M. , Carval T. , Chavagnac V. , Connelly D. , Fabian M. , Ghiron S. , Goslin J. , Miranda J. M. , Reverdin G. , Sarrazin J. , Waldmann C. , Sarradin P. M.
Published: June 2010

Colaço, A., Blandin, J., Cannat, M., Carval, T., Chavagnac, V., Connelly, D., Fabian, M., Ghiron, S., Goslin, J., Miranda, J. M., Reverdin, G., Sarrazin, J., Waldmann, C., and Sarradin, M. 2011. MoMAR-D: a technological challenge to monitor the dynamics of the Lucky Strike vent ecosystem. – ICES Journal of Marine Science, 68: 416–424. The MoMAR (monitoring the Mid-Atlantic Ridge) project was initiated in 1998 by the InterRidge programme to promote and coordinate long-term multidisciplinary monitoring of hydrothermal vents at the Mid-Atlantic Ridge (MAR). The major objective of the project is to study vent ecosystem dynamics using a multidisciplinary approach from geophysics to microbiology over a period of a few decades. MoMAR-D is a demonstration project of MoMAR, partially funded by the European network of excellence ESONET (http://www.esonet-noe.org/). MoMAR-D aims to deploy and manage a multidisciplinary observing system at the Lucky Strike vent field for 1 year. This large hydrothermal field is located at the centre of one of the most volcanically active segments of the MAR. The project has been set up to monitor this region to capture evidence of volcanic events, observe interactions between faulting, magmatism, and hydrothermal circulations, and to evaluate the potential impacts of these environmental factors on the unusual communities colonizing hydrothermal vents. The MoMAR-D infrastructure consists of two sea monitoring nodes (SEAMON) acoustically linked to a surface buoy with satellite communication to a land-based station. The first node will be mainly dedicated to geophysical studies, whereas the second will focus on ecological studies and chemical fluxes. The infrastructure should have been deployed in September 2010 during the MoMARSAT cruise.
Distribution of paralarvae and small juvenile cephalopods in relation to primary production in an upwelling area off southern Brazil
Authors: Vidal Erica A. G. , Haimovici Manuel , Hackbart Vivian C. S.
Published: June 2010

Vidal, E. A. G., Haimovici, M., and Hackbart, V. C. S. 2010. Distribution of paralarvae and small juvenile cephalopods in relation to primary production in an upwelling area off southern Brazil. – ICES Journal of Marine Science, 67: 1346–1352. The distribution of paralarvae and small juvenile cephalopods sampled by a rectangular midwater trawl (opening area 8 m2) over the continental shelf off Cape Santa Marta Grande, southern Brazil (28°09′S–29°56′S) during spring 1989 is discussed. An intrusion of Brazil Current Tropical Water (22°C; 36.5) separates warm, less-saline water (22°C; 35.2) from cooler, more-saline water (15°C; 36.4). Prevailing northeasterly winds led to upwelling of South Atlantic Central Water over the shelf, promoting high Chl a concentrations. Three species constituted 99% of the 628 cephalopods collected: Illex argentinus (n = 540; 4–40 mm mantle length, ML), Argonauta nodosa (n = 46; 2–19 mm ML), and Loligo sanpaulensis (n = 42, 2–21 mm ML). Segregation of I. argentinus juveniles of similar size suggests school formation as small as 10 mm ML. The presence of mature males along with fertilized female A. nodosa indicates mating early in life. There was a consistent and direct link between high plankton production and high densities of juvenile cephalopods through a short and ecologically efficient food chain. The relationship between production, pycnocline intensity, and the density of paralarvae and juveniles revealed suitable conditions for survival and growth during the upwelling season.
Time is Not A Theoretical Variable
Authors: Beck Nathaniel
Published: June 2010

Carter and Signorino (2010) (hereinafter “CS”) add another arrow, a simple cubic polynomial in time, to the quiver of the binary time series—cross-section data analyst; it is always good to have more arrows in one's quiver. Since comments are meant to be brief, I will discuss here only two important issues where I disagree: are cubic duration polynomials the best way to model duration dependence and whether we can substantively interpret duration dependence.
A review of potential factors relevant to coping in patients with advanced cancer
Authors: Thomsen Thora Grothe , Rydahl‐Hansen Susan , Wagner Lis
Published: June 2010

Aims.  The aim was to identify characteristics that are considered to describe coping in patients with advanced cancer, as seen from a patient perspective. Based on the identified characteristics, the second aim was to identify potential factors that are relevant to coping in patients with advanced cancer.

Background.  Patients with advanced or incurable cancer often express a need for professional help to cope with their complex situation. Furthermore, the support of health care professionals may often be dominated by a focus on symptom treatment and its effectiveness and less on the kind of needs that the patients consider most important.

Design.  Systematic review.

Methods.  Based on guidelines from the Centre for Review and Dissemination, York University, a systematic literature search identified 30 articles. Using Lazarus and Folkman’s theory of coping as the theoretical framework, relevant data were extracted, analysed and synthesised.

Results.  Based on the identification of 160 characteristics, seven potential factors emerged: ‘Creating meaning’, ‘Support systems’, ‘Minimising the impact of cancer’, ‘Bodily and mental functioning’, ‘Control’ and ‘Uncertainty’ and ‘Emotions’.

Conclusions.  The results indicate that emotion‐focused coping may be used more often by patients with advanced cancer than problem‐focused coping. However, it cannot be ruled out that this finding relates to a nomenclature of coping function that is too limited. Furthermore, the results indicate that the seven potential factors may be related to both the appraisal process and the coping process.

Relevance to clinical practice.  By choosing, as the theoretical framework, Lazarus and Folkman’s theory about the connection between the stress, appraisal and coping processes, it has been possible to highlight how the identified factors may be used as the underlying basis of clinical questions focusing on the patients’ appraisal of and coping with the concrete situation.
Developmental expression of Xenopus myosin 1d and identification of a myo1d tail homology that overlaps TH1
Authors: LeBlanc‐Straceski Janine M. , Sokac Anna , Bement William , Sobrado Pablo , Lemoine Laura
Published: June 2010

Xenopus laevis myosin 1d (XlMyo1d) is a member of the myosin I class, subclass 4. Members of this class are single headed, bind calmodulin light chains and have lipid binding domains in their tails. The rat myo1d homologue has been implicated in endosome vesicle recycling in epithelial cells. Mutations in the Drosophila myosin 1d homologue cause situs inversus in the abdomen. The XlMyo1d cDNA has been cloned and the derived amino acid sequence is 80% identical to the rat and human homologues. Sequence comparison revealed a novel isoform‐specific tail homology embedded in the Tail Homology 1 (TH1) domain characteristic of myosin I isoforms. Western blot analysis using a polyclonal antibody raised against an isoform‐specific peptide showed that the protein is present in eggs and levels increase at early neurula through tadpole stages. Whole mount in situ hybridization using a probe containing the 5′UTR (untranslated region) showed that XlMyo1d mRNA is expressed in neural tube, pre‐somitic mesoderm, somites and all three segments of cranial neural crest cells during their migration. Sections of the in situ hybridizations revealed that during somitogenesis, XlMyo1d mRNA was localized to a stripe overlapping the nuclear region of somites during early tadpole stages.
Analysis of gene expressions of embryonic stem‐derived Pdx1‐expressing cells: Implications of genes involved in pancreas differentiation
Authors: Yoshida Tetsu , Murata Kazuya , Shiraki Nobuaki , Kume Kazuhiko , Kume Shoen
Published: June 2010

We have recently reported the method by which embryonic stem (ES) cells were induced into Pdx1‐expressing cells. To gain insights into the ES cell‐derived Pdx1‐expressing cells, we examined gene expression profiles of the cells by microarray experiments. Microarray analyses followed by a comparison with the data of the cells in developing pancreatic and adult islet suggested that the ES cell‐derived Pdx1‐positive cells were immature pancreatic progenitor cells with endodermal characteristics. The analyses of the genes upregulated in the ES cell‐derived Pdx1‐positive cells would give us knowledge on early pancreatic development. Here, we first listed the genes and found that these contained not only those known to be expressed in the endoderm or pancreatic progenitor cells, but also those known to be involved in left–right axis formation. Second, we examined the gene expression patterns and found that several genes were expressed in the ventral foregut lip at the anterior intestinal portal in E8.5 embryo. Given that the Pdx1/GFP‐expressing cells are first observed in the same region at the anterior intestinal portal, these results suggest that the pancreatic progenitor cells first give rise at the ventral endoderm prior to the formation of dorsal and ventral pancreatic buds.
Statin use prior to ischemic stroke onset is associated with decreased in‐hospital mortality
Authors: Hassan Yahaya , Al‐Jabi Samah W. , Aziz Noorizan Abd , Looi Irene , Zyoud Sa’ed H.
Published: June 2010

Statins can reduce the risk of stroke in at‐risk populations and improve survival after acute ischemic stroke (AIS) among patients with previous statin use. This study aimed to investigate the impact of statin use before AIS onset on in‐hospital mortality and identify the factors related to in‐hospital mortality among patients with and without previous statin use. A retrospective cohort study of all patients with AIS attending hospital from June 1, 2008 to December 31, 2008. Data were collected from medical records including demographic information, diagnostic information, risk factors, previous statin use, and vital discharge status. Chi‐square, Fisher’s exact tests, student’s t‐test, and Mann–Whitney U test, whatever appropriate, were used to test the significance between the variables, and multiple logistic regression was used to identify factors associated with in‐hospital mortality. Altogether, 386 patients with AIS were studied, of which 113 (29.3%) had a documented previous statin use. A total of 62 (16.1%) patients with AIS died in hospital. In‐hospital mortality was significantly lower among previous statin users (P = 0.013). The presence of atrial fibrillation (AF) increased in‐hospital mortality among patients with or without previous statin use. The independent predictors for in‐hospital mortality among AIS patients without previous statin use were the presence of diabetes mellitus (P = 0.047), AF (P = 0.045), and renal impairment (P < 0.001). The prophylactic administration of statins significantly reduces post‐AIS in‐hospital mortality. Furthermore, the identification of predictors of in‐hospital mortality might reduce death rates and enhance the application of specific therapeutic and management strategies to patients at a high risk of dying.
Effects of nitric oxide synthase inhibitors 1‐(2‐trifluoromethylphenyl) – imidazole (TRIM) and 7‐nitroindazole (7‐NI) on learning and memory in mice
Authors: Mutlu Oguz , Ulak Güner , Belzung Catherine
Published: June 2010

Nitric oxide (NO) plays an important role in hippocampal long‐term potentiation (LTP), which is involved in memory processes. This led to the hypothesis that nitric oxide synthase (NOS) inhibitors will have disturbing effects on learning and memory. The aim of our study was to investigate the effects of the new selective neuronal and inducible NOS inhibitor 1‐ (2‐trifluoromethylphenyl) imidazole (TRIM) (10–50 mg/kg) on learning and memory and compare it to the nonselective NOS inhibitor 7‐NI (15–45 mg/kg) using different behavioral tests in Swiss mice, thus clarifying the role of neuronal NOS (nNOS) and endothelial NOS (eNOS) in cognitive processes. TRIM had no specific effect on either learning or memory parameters, while 7‐NI (30 mg/kg) disturbed spatial memory in the probe trial of the Morris water maze test, which was performed on the last day of the test. No differences between TRIM and the control groups were observed, while 7‐NI (30 and 45 mg/kg) significantly disturbed memory in the novel object recognition test. In the social transmission of food preference test, both TRIM (50 mg/kg) and 7‐NI (45 mg/kg) impaired hippocampal olfactory memory, but the total food consumption was also significantly decreased at these doses. In the passive avoidance test, TRIM did not disturb the performance, while memory impairment was observed, even with lower doses of 7‐NI. All of these results suggest that TRIM has no clear effect on cognitive impairment compared to 7‐NI and that inhibition of both nNOS and eNOS are necessary for the deterioration of memory processes.
Are Older Workers Less Productive? A Case Study of Aged Care Workers in Australia*
Authors: WEI ZHANG , RICHARDSON SUE
Published: June 2010

Employers are reluctant to employ older workers. Is this because they are less productive than equivalent younger workers? This paper uses data from a 2007 census of residential aged care homes in Australia to examine the productivity differentials of workers at different ages. We estimate production functions that take into account the age profile of the workforce in each aged care residential facility. We find that for the facilities having high care residents only, the productivity of nurses, whose work is more demanding of specialist knowledge, keeps increasing with age while the rate of increase declines after age 50. In contrast, the productivity of carers, whose work is more demanding of physical capacity, is highest in middle age. The facilities with low care residents only provide a much lower level of services because their residents are less frail and more independent. In this case, none of the coefficients regarding the impacts of age on productivity is statistically significant – suggesting that older workers are good substitutes for younger ones.
Channelrhodopsin as a tool to investigate synaptic transmission and plasticity
Authors: Schoenenberger Philipp , Schärer Yan‐Ping Zhang , Oertner Thomas G.
Published: June 2010

The light‐gated cation channel channelrhodopsin‐2 (ChR2) has been used in a variety of model systems to investigate the function of complex neuronal networks by stimulation of genetically targeted neurons. In slice physiology, ChR2 opens the door to novel types of experiments and greatly extends the technical possibilities offered by traditional electrophysiology. In this short review, we first consider several technical aspects concerning the use of ChR2 in slice physiology, providing examples from our own work. More specifically, we discuss differences between light‐evoked action potentials and spontaneous or electrically induced action potentials. Our work implies that light‐evoked action potentials are associated with increased calcium influx and a very high probability of neurotransmitter release. Furthermore, we point out the factors limiting the spatial resolution of ChR2 activation. Secondly, we discuss how synaptic transmission and plasticity can be studied using ChR2. Postsynaptic depolarization induced by ChR2 can be combined with two‐photon glutamate uncaging to potentiate visually identified dendritic spines. ChR2‐mediated stimulation of presynaptic axons induces neurotransmitter release and reliably activates postsynaptic spines. In conclusion, ChR2 is a powerful tool to investigate activity‐dependent changes in structure and function of synapses.
Adenosine receptor inhibition with theophylline attenuates the skin blood flow response to local heating in humans
Authors: Fieger Sarah M. , Wong Brett J.
Published: June 2010

Mechanisms underlying the robust cutaneous vasodilatation in response to local heating of human skin remain unresolved. Adenosine receptor activation has been shown to induce vasodilatation via nitric oxide, and a substantial portion of the plateau phase to local heating of human skin has been shown to be dependent on nitric oxide. The purpose of this study was to investigate a potential role for adenosine receptor activation in cutaneous thermal hyperaemia in humans. Six subjects were equipped with four microdialysis fibres on the ventral forearm. Sites were randomly assigned to receive one of the following four treatments: (1) lactated Ringer solution to serve as a control; (2) 4 mm theophylline, a competitive, non‐selective A1/A2 adenosine receptor antagonist; (3) 10 mm Nω‐nitro‐l‐arginine methyl ester (l‐NAME) to inhibit NO synthase; or (4) combined 4 mm theophylline + 10 mm l‐NAME. Following baseline measurements, each site was locally heated from a baseline temperature of 33°C to 42°C at a rate of 1°C (10 s)−1, and skin blood flow was monitored via laser‐Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as LDF divided by mean arterial pressure and normalized to maximal values (CVCmax) via local heating to 43°C and infusion of 28 mm sodium nitroprusside. The initial peak was significantly reduced in theophylline (68 ± 2% CVCmax) and l‐NAME sites (54 ± 5% CVCmax) compared with control sites (81 ± 2% CVCmax; P < 0.01 and P < 0.001, respectively). Combined theophylline +l‐NAME (52 ± 5% CVCmax) reduced the initial peak compared with control and theophylline sites, but was not significantly different compared with l‐NAME sites. The secondary plateau was attenuated in theophylline (77 ± 2% CVCmax), l‐NAME (60 ± 2% CVCmax) and theophylline +l‐NAME (53 ± 1% CVCmax) compared with control sites (94 ± 2% CVCmax; P < 0.001 for all conditions). The secondary plateau was reduced in l‐NAME compared with theophylline sites (P < 0.001), and combined theophylline +l‐NAME further reduced the secondary plateau compared with theophylline‐ (P < 0.001) and l‐NAME‐only sites (P < 0.05). These data suggest that adenosine receptor activation directly contributes to cutaneous thermal hyperaemia, as evidenced by the reduced initial peak and secondary plateau in theophylline sites. These data further suggest that a portion of the NO response may be explained by adenosine receptor activation; however, a substantial portion of the NO response is independent of adenosine receptor activation.
Investigations of magnetic overlayers at the Advanced Photon Source
Authors: Tobin J. G. , Yu S.-W. , Butterfield M. T. , Komesu Takashi , Waddill G. D.
Published: June 2010

Magnetic overlayers of Fe and Co have been investigated with x-ray magnetic circular dichroism in x-ray absorption spectroscopy and photoelectron spectroscopy, including spin-resolved photoelectron spectroscopy, at Beamline 4 at the Advanced Photon Source. Particular emphasis was placed upon the interrogation of the 2p levels of the Fe.
High rate reactive magnetron sputter deposition of Al-doped ZnO with unipolar pulsing and impedance control system
Authors: Nishi Yasutaka , Hirohata Kento , Tsukamoto Naoki , Sato Yasushi , Oka Nobuto , Shigesato Yuzo
Published: June 2010

Al-doped ZnO (AZO) films were deposited on quartz glass substrates, unheated and heated to 200 °C, using reactive sputtering with a special feedback system of discharge impedance combined with midfrequency pulsing. A planar Zn–Al alloy target was connected to the switching unit, which was operated in a unipolar pulse mode. The oxidation of the target surface was precisely controlled by a feedback system for the entire O2 flow ratio including “the transition region.” The deposition rate was about 10–20 times higher than that for films deposited by conventional sputtering using an oxide target. A deposition rate of AZO films of 390 nm/min with a resistivity of 3.8×10−4 Ω cm and a transmittance in the visible region of 85% was obtained when the films were deposited on glass substrates heated to 200 °C with a discharge power of 4 kW.
Synthesis and structural characterization of Fe–O nanonetworks
Authors: Carbajal-Franco G. , Ramana C. V.
Published: June 2010

Nanostructures of Fe oxides and hydroxides with varying morphologies have been prepared in aqueous media by precipitation of iron nitrate and ammonium hydroxide. The approach is based on a simple wet-chemical route involving different solutions of Fe-oxide/hydroxide particles in suspension and acetic acid at different concentrations and subject to heat treatment at 373 K. The growth and structural characteristics have been investigated using x-ray diffraction (XRD) and high-resolution scanning electron microscopy (HRSEM). XRD results indicate that the solids obtained from aqueous stage exhibit goethite [α-FeO(OH)] with average particle size of 2–3 nm, while the samples with acetic acid addition show hematite (α-Fe2O3) with average size of ∼20 nm. HRSEM results confirm the presence of particles of ∼100 nm in samples with no acetic acid, while the samples with acetic acid exhibit nanoparticles of ∼20 nm. The analysis also indicates the presence of net-shaped structures and particles with high-dense porosity within the nanoregime depending on the concentration of acetic acid. Fe-oxide nanoparticles and networks are stable up to a temperature of 773 K.
Evaluation of indium tin oxide films grown at room temperature by pulsed electron deposition
Authors: Nampoori Harshan V. , Rincon Veronica , Chen Mengwei , Kotru Sushma
Published: June 2010

Good quality Sn-doped In2O3 films with thickness of 30 nm were deposited using a vapor deposition technique known as pulsed electron deposition. The films were deposited on (100) Si substrates, at room temperature from a ceramic target of indium tin oxide (90/10). A pulsed electron beam was used for ablation of the target. Voltage of the electron source was maintained at 18 kV with frequency of pulses at 3 Hz. Distance between source and target was maintained around 6 mm, and the substrate to target distance was ∼7 cm. Oxygen pressure in the chamber during growth was varied from 3.1 to 20 mTorr. To evaluate the quality of grown films, various characterization techniques were employed. The effect of oxygen chamber pressure on resistivity (ρ), carrier concentration (N), mobility (μ), and optical constants (n and k) was carried out. Optical transparency and electrical conductivity of the films were seen to improve with increasing oxygen pressure. Details about the film preparation and evaluation of properties are reported.
Studies of Al2O3 barriers for use in tunnel junctions for nonlocal spin detection experiments
Authors: Abel J. , Garramone J. J. , Sitnitsky I. L. , LaBella V. P.
Published: June 2010

Aluminum oxide films were grown on Si under ultrahigh vacuum conditions for use as tunnel barriers in spin injection studies. X-ray photoelectron spectroscopy was performed to characterize the film stoichiometry. It was observed that all the aluminum was bonded to the oxygen for the films grown in 1 nm steps. Whereas the 2 nm sample grown in one 2 nm step left a partially unoxidized aluminum film. Current-voltage measurements were performed and fitted to a tunnel model. The resistance area products fall within the range needed for spin injection and nonlocal readout.
The
Pseudomonas aeruginosa
Exopolysaccharide Psl Facilitates Surface Adherence and NF-κB Activation in A549 Cells
Authors: Byrd Matthew S. , Pang Bing , Mishra Meenu , Swords W. Edward , Wozniak Daniel J.
Published: June 2010

In order for the opportunistic Gram-negative pathogen
Pseudomonas aeruginosa
to cause an airway infection, the pathogen interacts with epithelial cells and the overlying mucous layer. We examined the contribution of the biofilm polysaccharide Psl to epithelial cell adherence and the impact of Psl on proinflammatory signaling by flagellin. Psl has been implicated in the initial attachment of
P
. 
aeruginosa
to biotic and abiotic surfaces, but its direct role in pathogenesis has not been evaluated (L. Ma, K. D. Jackson, R. M. Landry, M. R. Parsek, and D. J. Wozniak, J. Bacteriol. 188:8213–8221, 2006). Using an NF-κB luciferase reporter system in the human epithelial cell line A549, we show that both Psl and flagellin are necessary for full activation of NF-κB and production of the interleukin 8 (IL-8) chemokine. We demonstrate that Psl does not directly stimulate NF-κB activity, but indirectly as a result of increasing contact between bacterial cells and epithelial cells, it facilitates flagellin-mediated proinflammatory signaling. We confirm differential adherence of Psl and/or flagellin mutants by scanning electron microscopy and identify Psl-dependent membrane structures that may participate in adherence. Although we hypothesized that Psl would protect
P
. 
aeruginosa
from recognition by the epithelial cell line A549, we instead observed a positive role for Psl in flagellin-mediated NF-κB activation, likely as a result of increasing contact between bacterial cells and epithelial cells.

IMPORTANCE
Pseudomonas aeruginosa
is the predominant airway pathogen causing morbidity and mortality in individuals affected by the genetic disease cystic fibrosis.
P
. 
aeruginosa
can also cause severe pneumonia, burn wound infections, and sepsis, making its overall impact on human health significant. The attachment of
P
. 
aeruginosa
to host tissues, often leading to recalcitrant biofilm infections, and inflammation induced by flagellin are both important mechanisms of virulence. We explored the role of the biofilm polysaccharide Psl in the pathogenesis of
P
. 
aeruginosa
and found that Psl is required for surface adherence to A549 epithelial cells, and as an adhesin, it facilitates flagellin-mediated NF-κB activation. This work was done to better understand the initial events of infection and revealed that a biofilm polysaccharide contributes to inflammation in a novel manner.
Early gastric cancer in Europe
Authors: EVERETT S M , AXON A T R
Published: June 2010

Despite mass population screening and an incidence of EGC in Japan that is at least double that of the West, there seem to be no genuine differences in the clinicopathological features of the disease between the two regions. The macroscopic appearance, size, depth of invasion, frequency of lymph node invasion, and histology of EGC are all remarkably similar in Japan, Europe and America, as are sex and age distributions.

Patients with EGC are a number of years younger than those with advanced cancer. This is not surprising: Tsukuma et alfollowed 56 cases of EGC that were not surgically treated and estimated that the median “duration of EGC” before becoming advanced was 37 months.87 This suggests that EGC undergoes a period of slow growth before becoming advanced. Further differences between early and advanced cancers include a higher frequency of synchronous cancers and a longer symptom duration in EGC.

Unfavourable prognostic factors in EGC include lymph node invasion, and invasion through the muscularis mucosae, though it is not clear whether these are independent. Repeated attempts have been made to identify other prognostic factors, but no clear pattern has emerged, with the possible exceptions of patient age, tumour size, and the presence of ulceration.

The postsurgical outcome of EGC in the West is marginally less favourable than in Japan. In view of the similar clinical and pathological features in the two regions it seems likely, therefore, that this is because of the more aggressive surgical techniques traditionally used in Japan. Conversely, however, EMR has recently emerged as an important technique in Japan. Despite the advantages of low operative mortality and normal function of the postoperative stomach, there are also a number of potential disadvantages. It would seem sensible, therefore, to await the results of long term follow up studies before widespread adoption of EMR in Europe. Nevertheless, this technique should be considered for frail patients unfit for more radical surgery.
T cells of the human intestinal lamina propria are high producers of interleukin-10
Authors: Braunstein J , Qiao L , Autschbach F , Schürmann G , Meuer S
Published: June 2010

Background and aim—Some of the recently observed functional features characteristic of immunocompetent cells residing in the human intestinal lamina propria could be mediated by interleukin- 10 (IL-10). To investigate the role of IL-10 in the human intestinal mucosa, the regulation of IL-10 production by lamina propria T lymphocytes (LPL-T) was determined and compared with that of peripheral blood T lymphocytes (PBL-T).

Methods—Following activation by using different stimuli, IL-10 release by LPL-T and PBL-T into the supernatant was measured by enzyme linked immunosorbent assay (ELISA). In parallel, cell growth was determined by [3H]-thymidine incorporation.

Results—Neither LPL-T nor PBL-T release IL-10 constitutively. Triggering through CD2 or the T cell receptor (TCR)/CD3 complex in the presence of autologous monocytes induces significantly greater IL-10 secretion by LPL-T than by PBL-T. Engagement of the CD45 receptor enhances IL-10 release and proliferation of CD2 triggered CD45RO+ PBL-T. In contrast, it reduces CD2 induced IL-10 production by LPL-T without altering cell growth significantly .

Conclusions—Activated LPL-T release relatively high amounts of IL-10. Enhanced IL-10 production by activated LPL-T, in comparison with activated PBL-T, is not only related to the presence of a higher proportion of CD45RO+ T cells in the intestinal lamina propria, but is also caused by increased sensitivity of LPL-T to CD2 co-stimulation. The differential responsiveness of LPL-T, compared with PBL-T, to CD45 engagement demonstrates that CD45 could be involved in the altered CD2 reactivity of LPL-T.
Enhanced mucosal permeability and nitric oxide synthase activity in jejunum of mast cell deficient mice
Authors: Komatsu S , Grisham M B , Russell J M , Granger D N
Published: June 2010

Background—Recent reports have described a modulating influence of nitric oxide (NO) on intestinal mucosal permeability and have implicated a role for mast cells in this NO mediated process.

Aims—To assess further the contribution of mast cells to the mucosal permeability changes elicited by the NO synthase (NOS) inhibitor NG-nitro-l-arginine methylester (l-NAME), using mast cell deficient (W/WV) and mast cell replete mice (+/+).

Methods—Chromium-51 EDTA clearance (from blood to jejunal lumen), jejunal NOS and myeloperoxidase (MPO) activities, and plasma nitrate/nitrite levels were monitored.

Results—The increased EDTA clearance elicited by intraluminal l-NAME in W/WV mice (4.4-fold) was significantly greater than the response observed in control (+/+) mice (1.8-fold). The exacerbated response in W/Wv mice was greatly attenuated by pretreatment with either dexamethasone (1.3-fold) or the selective inducible NOS inhibitor, aminoguanidine (1.4-fold), and partially attenuated by the mast cell stabiliser, lodoxamide (2.9-fold). Jejunal inducible NOS activity was significantly higher in W/WV than in +/+ mice, while jejunal MPO was lower in W/WV mice than in +/+ mice, suggesting that the higher inducible NOS in W/WV does not result from the recruitment of inflammatory cells into the gut. The higher inducible NOS activity in the jejunum of W/WV was significantly reduced by dexamethasone treatment.

Conclusions—Our results suggest that mast cells normally serve to inhibit inducible NOS activity tonically in the gut and that inhibitors of NOS elicit a larger permeability response when this tonic inhibitory influence is released by mast cell depletion.