bluuebunny/crossref_metadata_2025 huggingface dataset:
Sexually transmitted infections, blood-borne viruses and risk behaviour in an Australian senior high school population—the SHLiRP study
Authors: Bowden Francis J. , O'Keefe Elissa J. , Primrose Ruth , Currie Marian J.
Published: November 2005

Objectives: To determine the feasibility and acceptability of screening for sexually transmitted infections and blood-borne viruses and to study the profile of sexual activity and other risk behaviours in a senior high school population. Methods: In this descriptive study we provided sexual health education and screening to students from two senior high schools in the Australian Capital Territory. We collected behavioural data using a self-administered questionnaire. Urines and swabs were tested for Chlamydia trachomatis (Ct), Neisseria gonorrhoea (Ng), Trichomonas vaginalis (Tv) and human papilloma virus (HPV). Blood specimens were tested for hepatitis B and C, HIV, herpes simplex viruses (HSV-1 and HSV-2) and syphilis. Results: A total of 795 students participated (31% of the enrolled population; female to male ratio 60 : 40) and 67.0% were sexually active. Of 795 students, 644 (81.0%) were screened. Rates of infection were Ct 1.1% (95% CI: 0.4–2.6), HPV 11.7% (95% CI: 7.4–17.3), HSV-1 32.5% (95% CI: 28.9–36.3), HSV-2 2.4% (95% CI: 1.3–3.9), hepatitis B surface antigen 0.3% (95% CI: 0.04–1.1) and hepatitis C antibodies 0.7% (95% CI: 0.07–1.6). Only 22.3% (95% CI: 19.3–25.7) of students had immunity to hepatitis B. There were no cases of HIV, gonorrhoea, trichomoniasis or syphilis. Of the sexually active students, 49.2% (95% CI: 38.9–59.2%) reported never or only sometimes using condoms, 41.5% (95% CI: 32.2–52.3%) reported unsafe drinking, 33.3% (95% CI: 23.9–43.1%) were smokers and 1.9% (95% CI: 0.2–7.0%) reported injecting drug use. Conclusions: Rates of STI and blood-borne viruses and immunity to hepatitis B were low in this population, but unsafe sex and other risk behaviours were common. We have demonstrated that STI screening, including serological testing, was well accepted in a senior high school population.
Do all women attending urban sexual health services need testing for gonorrhoea?
Authors: Read Tim R. H. , Chen Marcus Y. , Bradshaw Catriona S. , Beneragama Sriyakantha , Fairley Christopher K.
Published: November 2005

Asymptomatic women are often screened for gonorrhoea at Australian sexual health centres. The medical records of all women diagnosed with gonorrhoea at the Melbourne Sexual Health Centre (MSHC) between January 2002 and December 2003 were audited and the database was examined for risk factors in all women tested in 2003. Fifteen cases of gonorrhoea were identified among women at MSHC, all had symptoms or an identifiable risk factor. Asymptomatic women without risk factors may not require screening for Neisseria gonorrhoeae in low prevalence populations.
SUMO modification negatively modulates the transcriptional activity of CREB-binding protein via the recruitment of Daxx
Authors: Kuo Hong-Yi , Chang Che-Chang , Jeng Jen-Chong , Hu Hui-Mei , Lin Ding-Yen , Maul Gerd G. , Kwok Roland P. S. , Shih Hsiu-Ming
Published: November 2005

Small ubiquitin-like modifier (SUMO) modification is emerging as an important control in transcription regulation. Here, we show that CREB-binding protein (CBP), a versatile transcriptional coactivator for numerous transcription factors in response to diverse signaling events, can be modified by SUMO-1 at lysine residues 999, 1034, and 1057 both
in vitro
and
in vivo
. Mutation of the SUMO acceptor lysine residues either individually or in combination enhanced CBP transcriptional activity, and expression of a SUMO protease SENP2 potentiated the transcriptional activity of CBP wild-type but not its sumoylation mutant, indicating that SUMO modification negatively regulates CBP transcriptional activity. Furthermore, we demonstrated an interaction of SUMO-1-modified CBP with the transcriptional corepressor Daxx and an essential role of Daxx in mediating SUMO-dependent transcriptional regulation of CBP through histone deacetylase 2 recruitment. Together, our findings indicate that SUMO modification and subsequent recruitment of Daxx represent a previously undescribed mechanism in modulating CBP transcriptional potential.
MicroRNAs control translation initiation by inhibiting eukaryotic initiation factor 4E/cap and poly(A) tail function
Authors: Humphreys David T. , Westman Belinda J. , Martin David I. K. , Preiss Thomas
Published: November 2005

MicroRNAs (miRNAs) repress translation of target mRNAs by interaction with partially mismatched sequences in their 3′ UTR. The mechanism by which they act on translation has remained largely obscure. We examined the translation of mRNAs containing four partially mismatched miRNA-binding sites in the 3′ UTR in HeLa cells cotransfected with a cognate miRNA. The mRNAs were prepared by
in vitro
transcription and were engineered to employ different modes of translation initiation. We find that the 5′ cap structure and the 3′ poly(A) tail are each necessary but not sufficient for full miRNA-mediated repression of mRNA translation. Replacing the cap structure with an internal ribosome entry site from either the cricket paralysis virus or the encephalomyocarditis virus impairs miRNA-mediated repression. Collectively, these results demonstrate that miRNAs interfere with the initiation step of translation and implicate the cap-binding protein eukaryotic initiation factor 4E as a molecular target.
CD4+CD25+regulatory T cells limit the risk of autoimmune disease arising from T cell receptor crossreactivity
Authors: Stephens Leigh A. , Gray David , Anderton Stephen M.
Published: November 2005

The molecular-mimicry theory proposes that immune crossreactivity between microbial and self-antigen is the initiating event in the activation of autoaggressive immune responses leading to autoimmune disease. In support of this possibility, it is now accepted that T cell recognition of antigen is highly degenerate. However, it is to be expected that the immune system would have evolved mechanisms to counter such a potential danger. We studied the influence of CD4+CD25+regulatory T cells (Treg) on the ability of suboptimal T cell receptor ligands to provoke autoimmunity. By using CD4+T cell-driven experimental autoimmune encephalomyelitis as a model, it was found that depletion of CD4+CD25+Foxp3+Treg allowed pathology to develop in response to suboptimal T cell stimulation. These data demonstrate the importance of Treg in raising the threshold of triggering of autoreactive T cell responses, thus limiting the risk of autoimmune disease due to molecular mimicry.
Adaptive shift in the domain of negative stiffness during spontaneous oscillation by hair bundles from the internal ear
Authors: Le Goff Loïc , Bozovic Dolores , Hudspeth A. J.
Published: November 2005

When a hair cell of the bullfrog's sacculus is maintained
in vitro
under native ionic conditions, its mechanosensitive hair bundle may oscillate spontaneously. This movement has been hypothesized to result from the interaction of the bundle's negative stiffness, which creates a region of mechanical instability, with a myosin-based adaptation mechanism that continually repositions the bundle there. To test this proposition, we used a flexible stimulus fiber in an analog feedback loop to measure the displacement-force relation of an oscillating hair bundle. A digital signal processor was used to monitor spontaneous oscillations in real time and trigger measurements at particular phases of the movement cycle. By comparing the displacement-force curves obtained at the two extremes of a hair bundle's motion, we demonstrated a shift in the negative-stiffness region whose direction, orientation, magnitude, and kinetics agreed with the predictions of the gating-spring theory. The results are in accordance with the idea that adaptation underlies spontaneous hair-bundle oscillation, and therefore powers the active process that also amplifies and tunes the hair cell's mechanical responsiveness.
Some heuristics and results for small cycles of the discrete logarithm
Authors: Holden Joshua , Moree Pieter
Published: November 2005

Brizolis asked the question: does every prime

p
p

have a pair

(
g
,
h
)

(g,h)

such that

h
h

is a fixed point for the discrete logarithm with base

g
g

? The first author previously extended this question to ask about not only fixed points but also two-cycles, and gave heuristics (building on work of Zhang, Cobeli, Zaharescu, Campbell, and Pomerance) for estimating the number of such pairs given certain conditions on

g
g

and

h
h

. In this paper we extend these heuristics and prove results for some of them, building again on the aforementioned work. We also make some new conjectures and prove some average versions of the results.
Minimality and other properties of the width-𝑤 nonadjacent form
Authors: Muir James , Stinson Douglas
Published: November 2005

Let

w
≥
2

w \geq 2

be an integer and let

D
w

D_w

be the set of integers that includes zero and the odd integers with absolute value less than

2

w
−
1

2^{w-1}

. Every integer

n
n

can be represented as a finite sum of the form

n
=
∑

a
i

2
i

n = \sum a_i 2^i

, with

a
i

∈

D
w

a_i \in D_w

, such that of any

w
w

consecutive

a
i

a_i

’s at most one is nonzero. Such representations are called width-

w
w

nonadjacent forms (

w
w

-NAFs). When

w
=
2

w=2

these representations use the digits

{
0
,
±
1
}

\{0,\pm 1\}

and coincide with the well-known nonadjacent forms. Width-

w
w

nonadjacent forms are useful in efficiently implementing elliptic curve arithmetic for cryptographic applications. We provide some new results on the

w
w

-NAF. We show that

w
w

-NAFs have a minimal number of nonzero digits and we also give a new characterization of the

w
w

-NAF in terms of a (right-to-left) lexicographical ordering. We also generalize a result on

w
w

-NAFs and show that any base 2 representation of an integer, with digits in

D
w

D_w

, that has a minimal number of nonzero digits is at most one digit longer than its binary representation.
Extension of a class of periodizing variable transformations for numerical Integration
Authors: Sidi Avram
Published: November 2005

ClassSm{\mathcal S}_mvariable transformations with integermm, for numerical computation of finite-range integrals, were introduced and studied by the author in the paper [A. Sidi, A new variable transformation for numerical integration,Numerical Integration IV,1993 (H. Brass and G. Hämmerlin, eds.), pp. 359–373.] A representative of this class is thesinm\sin ^m-transformation that has been used with lattice rules for multidimensional integration. These transformations “periodize” the integrand functions in a way that enables the trapezoidal rule to achieve very high accuracy, especially with evenmm. In the present work, we extend these transformations toarbitraryvalues ofmm, and give a detailed analysis of the resulting transformed trapezoidal rule approximations. We show that, with suitablemm, they can be very useful in different situations. We prove, for example, that if the integrand function is smooth on the interval of integration and vanishes at the endpoints, then results of especially high accuracy are obtained by taking2m2mto be an odd integer. Such a situation can be realized in general by subtracting from the integrand the linear interpolant at the endpoints of the interval of integration. We also illustrate some of the results with numerical examples via the extendedsinm\sin ^m-transformation.
On computing rational Gauss-Chebyshev quadrature formulas
Authors: Van Deun Joris , Bultheel Adhemar , González Vera Pablo
Published: November 2005

We provide an algorithm to compute the nodes and weights for Gauss-Chebyshev quadrature formulas integrating exactly in spaces of rational functions with arbitrary real poles outside

[
−
1
,
1
]

[-1,1]

. Contrary to existing rational quadrature formulas, the computational effort is very low, even for extremely high degrees, and under certain conditions on the poles it can be shown that the complexity is of order

O
(
n
)

O(n)

. This method is based on the derivation of explicit expressions for Chebyshev orthogonal rational functions, which are (thus far) the only examples of explicitly known orthogonal rational functions on

[
−
1
,
1
]

[-1,1]

with arbitrary real poles outside this interval.
The trace of totally positive algebraic integers
Authors: Aguirre Julián , Bilbao Mikel , Peral Juan
Published: November 2005

For all totally positive algebraic numbers

α
\alpha

except a finite number of explicit exceptions, the following inequality holds:
\[

1
d

(

α
1

+
⋯
+

α
d

)
>
max
(
1.780022
,
1.66
+

α
1

)
,

\frac {1}{d}\,(\alpha _1+\dots +\alpha _d)>\max (1.780022,1.66+\alpha _1),

\]
where

d
d

is the degree of

α
\alpha

and

0
>

α
1

>
⋯
>

α
d

0>\alpha _1>\dots >\alpha _d

its conjugates. This improves previous results of Smyth, Flammang and Rhin.
Normal integral bases for 𝐴₄ extensions of the rationals
Authors: Cougnard Jean
Published: November 2005

We give an algorithm for constructing normal integral bases of tame Galois extensions of the rationals with group

A
4

A_4

. Using earlier works we can do the same until degree

15
15

.
An efficient numerical scheme for precise time integration of a diffusion-dissolution/precipitation chemical system
Authors: Faugeras Blaise , Pousin Jérôme , Fontvieille Franck
Published: November 2005

A numerical scheme based on an operator splitting method and a dense output event location algorithm is proposed to integrate a diffusion-dissolution/precipitation chemical initial-boundary value problem with jumping nonlinearities. The numerical analysis of the scheme is carried out and it is proved to be of order 2 in time. This global order estimate is illustrated numerically on a test case.
The multi-symplecticity of partitioned Runge-Kutta methods for Hamiltonian PDEs
Authors: Hong Jialin , Liu Hongyu , Sun Geng
Published: November 2005

In this article we consider partitioned Runge-Kutta (PRK) methods for Hamiltonian partial differential equations (PDEs) and present some sufficient conditions for multi-symplecticity of PRK methods of Hamiltonian PDEs.
Stability analysis for delay differential equations with multidelays and numerical examples
Authors: Sun Leping
Published: November 2005

In this paper we are concerned with the asymptotic stability of the delay differential equation
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="x prime left-parenthesis t right-parenthesis equals upper A 0 x left-parenthesis t right-parenthesis plus sigma-summation Underscript k equals 1 Overscript n Endscripts upper A Subscript k Baseline x left-parenthesis t Subscript tau Sub Subscript k Subscript Baseline right-parenthesis comma">

x

′

(
t
)
=

A
0

x
(
t
)
+

∑

k
=
1

n

A
k

x
(

t

τ
k

)
,

x^{\prime }(t)=A_0x(t)+\sum _{k=1}^nA_kx(t_{\tau _k}),

\]
where

A
0

,

A
k

∈

C

d
×
d

A_0,A_k\in C^{d\times d}

are constant complex matrices, and
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="x left-parenthesis t Subscript tau Sub Subscript k Subscript Baseline right-parenthesis equals left-parenthesis x 1 left-parenthesis t minus tau Subscript k Baseline 1 Baseline right-parenthesis comma x 2 left-parenthesis t minus tau Subscript k Baseline 2 Baseline right-parenthesis comma ellipsis comma x Subscript d Baseline left-parenthesis t minus tau Subscript k d Baseline right-parenthesis right-parenthesis Superscript upper T Baseline comma tau Subscript k l Baseline greater-than 0">

x
(

t

τ
k

)
=
(

x
1

(
t
−

τ

k
1

)
,

x
2

(
t
−

τ

k
2

)
,
…
,

x
d

(
t
−

τ

k
d

)

)
T

,

τ

k
l

>
0

x(t_{\tau _k})= (x_1(t-\tau _{k1}),x_2(t-\tau _{k2}),\dots ,x_d(t-\tau _{kd}))^T,\tau _{kl}>0

stand for

n
×
d

n\times d

constant delays

(
k
=
1
,
…
,
n
,
l
=
1
,
…
,
d
)

(k=1,\dots ,n,l=1,\dots ,d)

. We obtain two criteria for stability through the evaluation of a harmonic function on the boundary of a certain region. We also get similar results for the neutral delay differential equation
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="x prime left-parenthesis t right-parenthesis equals upper L x left-parenthesis t right-parenthesis plus sigma-summation Underscript i equals 1 Overscript m Endscripts upper M Subscript i Baseline x left-parenthesis t minus tau Subscript i Baseline right-parenthesis plus sigma-summation Underscript j equals 1 Overscript n Endscripts upper N Subscript j Baseline x prime left-parenthesis t minus tau prime Subscript j right-parenthesis comma">

x

′

(
t
)
=
L
x
(
t
)
+

∑

i
=
1

m

M
i

x
(
t
−

τ
i

)
+

∑

j
=
1

n

N
j

x

′

(
t
−

τ
j

′

)
,

x^{\prime }(t)=Lx(t)+\sum _{i=1}^mM_ix(t-\tau _i)+\sum _{j=1}^nN_jx^{\prime }(t-\tau _j^{\prime }),

\]
where

L
,

M
i

,

L,M_i,

and

N
j

∈

C

d
×
d

N_j\in C^{d\times d}

are constant complex matrices and

τ
i

,

τ
j

′

>
0

\tau _i,\tau _j^{\prime }>0

stands for constant delays

(
i
=
1
,
…
,
m

(i=1,\dots ,m

,

j
=
1
,
…
,
n
)

j=1,\dots ,n)

. Numerical examples on various circumstances are shown to check our results which are more general than those already reported.
WindowMasker: window-based masker for sequenced genomes
Authors: Morgulis Aleksandr , Gertz E. Michael , Schäffer Alejandro A. , Agarwala Richa
Published: November 2005

Motivation: Matches to repetitive sequences are usually undesirable in the output of DNA database searches. Repetitive sequences need not be matched to a query, if they can be masked in the database. RepeatMasker/Maskeraid (RM), currently the most widely used software for DNA sequence masking, is slow and requires a library of repetitive template sequences, such as a manually curated RepBase library, that may not exist for newly sequenced genomes.

Results: We have developed a software tool called WindowMasker (WM) that identifies and masks highly repetitive DNA sequences in a genome, using only the sequence of the genome itself. WM is orders of magnitude faster than RM because WM uses a few linear-time scans of the genome sequence, rather than local alignment methods that compare each library sequence with each piece of the genome. We validate WM by comparing BLAST outputs from large sets of queries applied to two versions of the same genome, one masked by WM, and the other masked by RM. Even for genomes such as the human genome, where a good RepBase library is available, searching the database as masked with WM yields more matches that are apparently non-repetitive and fewer matches to repetitive sequences. We show that these results hold for transcribed regions as well. WM also performs well on genomes for which much of the sequence was in draft form at the time of the analysis.

Availability: WM is included in the NCBI C++ toolkit. The source code for the entire toolkit is available at . Once the toolkit source is unpacked, the instructions for building WindowMasker application in the UNIX environment can be found in file src/app/winmasker/README.build.

Contact:  richa@helix.nih.gov

Supplementary information: Supplementary data are available at .
Mean curvature as a major determinant of β-sheet propensity
Authors: Koh Eunhee , Kim Taehyo , Cho Hyun-soo
Published: November 2005

Motivation: Despite the importance of β-sheets as building blocks in proteins and also toxic elements in the pathological disorders, ranging from Alzheimer's disease to mad cow diease, the principles underlying their stability are not well understood. Non-random β-sheet propensities of amino acids have been revealed both by their distinct statistical preferences within known protein structures and by the relative thermodynamic scales through the experimental host-guest systems. However, recent fitting analysis has proved that a native β-sheet conforms to a minimal surface with zero mean curvature, like the physical model of soap films.

Results: We here suggest that the stability of a residue in the all β-sheet proteins can be measured with its mean curvature parameter, using discrete differential geometry. The sharply decreasing mean curvature with increasing number of β-strands identifies a significant cooperative effect whereby the interstrand interaction increases in strength with the number of β-strands. Furthermore, strong correlations of mean curvatures with previous β-sheet propensities of amino acids show that their intrinsic differences in adopting the ideal β-sheet structure are affected by the water-accessible area of side-chains, and result in the distinct statistical and thermodynamic β-sheet propensities. Therefore, we conclude that mean curvature should be considered as the significant stability index of a β-sheet structure.

Contact:  ehkoh@yonsei.ac.kr
Patika
web: a Web interface for analyzing biological pathways through advanced querying and visualization
Authors: Dogrusoz U. , Erson E. Z. , Giral E. , Demir E. , Babur O. , Cetintas A. , Colak R.
Published: November 2005

Summary: Patikaweb provides a Web interface for retrieving and analyzing biological pathways in the Patika database, which contains data integrated from various prominent public pathway databases. It features a user-friendly interface, dynamic visualization and automated layout, advanced graph-theoretic queries for extracting biologically important phenomena, local persistence capability and exporting facilities to various pathway exchange formats.

Availability: The Web site is freely accessible to non-commercial users from

Contact:  patikaweb@cs.bilkent.edu.tr

Supplementary information: Detailed information is available on the tool Web site (), including key features, screenshots and User’s Guide.
Highly consistent patterns for inherited human diseases at the molecular level
Authors: López-Bigas Núria , Blencowe Benjamin J. , Ouzounis Christos A.
Published: November 2005

Over 1600 mammalian genes are known to cause an inherited disorder, when subjected to one or more mutations. These disease genes represent a unique resource for the identification and quantification of relationships between phenotypic attributes of a disease and the molecular features of the associated disease genes, including their ascribed annotated functional classes and expression patterns. Such analyses can provide a more global perspective and a deeper understanding of the probable causes underlying human hereditary diseases. In this perspective and critical view of disease genomics, we present a comparative analysis of genes reported to cause inherited diseases in humans in terms of their causative effects on physiology, their genetics and inheritance modes, the functional processes they are involved in and their expression profiles across a wide spectrum of tissues. Our analysis reveals that there are more extensive correlations between these attributes of genetic disease genes than previously appreciated. For instance, the functional pattern of genes causing dominant and recessive diseases is markedly different. Also, the function of the genes and their expression correlate with the type of disease they cause when mutated. The results further indicate that a comparative genomics approach for the analysis of genes linked to human genetic diseases will facilitate the elucidation of the underlying molecular and cellular mechanisms.

Contact:  nuria.lopez@crg.es; ouzounis@ebi.ac.uk

Supplementary information:
Automatic assignment of biomedical categories: toward a generic approach
Authors: Ruch Patrick
Published: November 2005

Motivation: We report on the development of a generic text categorization system designed to automatically assign biomedical categories to any input text. Unlike usual automatic text categorization systems, which rely on data-intensive models extracted from large sets of training data, our categorizer is largely data-independent.

Methods: In order to evaluate the robustness of our approach we test the system on two different biomedical terminologies: the Medical Subject Headings (MeSH) and the Gene Ontology (GO). Our lightweight categorizer, based on two ranking modules, combines a pattern matcher and a vector space retrieval engine, and uses both stems and linguistically-motivated indexing units.

Results and Conclusion: Results show the effectiveness of phrase indexing for both GO and MeSH categorization, but we observe the categorization power of the tool depends on the controlled vocabulary: precision at high ranks ranges from above 90% for MeSH to <20% for GO, establishing a new baseline for categorizers based on retrieval methods.

Contact:  Patrick.Ruch@sim.hcuge.ch
An efficient randomized algorithm for contact-based NMR backbone resonance assignment
Authors: Kamisetty Hetunandan , Bailey-Kellogg Chris , Pandurangan Gopal
Published: November 2005

Motivation: Backbone resonance assignment is a critical bottleneck in studies of protein structure, dynamics and interactions by nuclear magnetic resonance (NMR) spectroscopy. A minimalist approach to assignment, which we call ‘contact-based’, seeks to dramatically reduce experimental time and expense by replacing the standard suite of through-bond experiments with the through-space (nuclear Overhauser enhancement spectroscopy, NOESY) experiment. In the contact-based approach, spectral data are represented in a graph with vertices for putative residues (of unknown relation to the primary sequence) and edges for hypothesized NOESY interactions, such that observed spectral peaks could be explained if the residues were ‘close enough’. Due to experimental ambiguity, several incorrect edges can be hypothesized for each spectral peak. An assignment is derived by identifying consistent patterns of edges (e.g. for α-helices and β-sheets) within a graph and by mapping the vertices to the primary sequence. The key algorithmic challenge is to be able to uncover these patterns even when they are obscured by significant noise.

Results: This paper develops, analyzes and applies a novel algorithm for the identification of polytopes representing consistent patterns of edges in a corrupted NOESY graph. Our randomized algorithm aggregates simplices into polytopes and fixes inconsistencies with simple local modifications, called rotations, that maintain most of the structure already uncovered. In characterizing the effects of experimental noise, we employ an NMR-specific random graph model in proving that our algorithm gives optimal performance in expected polynomial time, even when the input graph is significantly corrupted. We confirm this analysis in simulation studies with graphs corrupted by up to 500% noise. Finally, we demonstrate the practical application of the algorithm on several experimental β-sheet datasets. Our approach is able to eliminate a large majority of noise edges and to uncover large consistent sets of interactions.

Availability: Our algorithm has been implemented in the platform-independent Python code. The software can be freely obtained for academic use by request from the authors.

Contact:  cbk@cs.dartmouth.edu
Diffraction by an elastic wedge with stress-free boundary: existence and uniqueness
Authors: Kamotski Vladimir V , Lebeau Gilles
Published: November 2005

Applying the spectral function techniques, developed by Croisille and Lebeau, we prove the existence of solutions to problems of plane and cylindrical waves diffraction by an elastic wedge with stress-free boundary conditions. We also formulate radiation conditions, under which the uniqueness holds. The latter implies absolute continuity of the spectrum of the Lamé operator in a wedge domain with stress-free boundary.
Risk factors for glucose intolerance in Danish women with polycystic ovary syndrome
Authors: Trolle Birgitta , Lauszus Finn Friis
Published: November 2005

Background.  Women with polycystic ovary syndrome (PCOS) are reported to be at risk for glucose intolerance. The aim of the study was to describe these risk factors in a population of Danish PCOS women attending a gynecologic clinic and to identify the parameters with the strongest correlation to the fasting blood glucose levels. In addition, we studied whether the oral glucose tolerance test (OGTT) diagnosed more cases of glucose intolerance in this PCOS population than the fasting plasma glucose value (FPG) alone.

Methods.  Cross‐sectional study of 91 women with oligomenorrhea or amenorrhea and elevated serum testosterone, followed by an OGTT in 27 of the women.

Results.  Women with a FPG above normal were older and had a higher body mass index (BMI), cholesterol, and triglycerides and a lower sexual hormone binding globulin (SHBG). Of the 21 women older than 34, eight (38%) had a FPG above normal. The OGTT study showed that one of five with abnormal glucose tolerance would not have been diagnosed, if the FPG alone had been performed.

Conclusions.  In this study, 38% of women with symptoms of PCOS over the age of 34 had abnormal blood glucose values. These women should receive blood glucose testing regardless of BMI, testosterone levels and family history of type 2 diabetes mellitus. An OGTT may be necessary to find all cases of impaired glucose intolerance.
The impact of oxygen tension on developmental competence of post‐thaw human embryos
Authors: Petersen Astrid , Mikkelsen Anne Lis , Lindenberg Svend
Published: November 2005

The present study compares the culture of human embryos using two different culture systems: a conventional culture incubator with humidified atmospheric air supplemented with 5% CO2 and a closed culture incubator with a humidified 5% O2 and 5% (5.2–5.5) CO2 and 90% N2 partial pressure.

A total of 225 cryopreserved embryos were donated after informed consent and thawed in two batches of 100 and 125 embryos separated by 1 week. A total of 126 (56%) embryos survived the thawing procedure having at least one living blastomere. After thawing, the embryos were randomly allocated to culture in a 5% oxygen partial pressure (n = 65) or to culture in a 20% oxygen partial pressure (n = 61). The embryos were hereafter cultured for 4 days and the number of embryos developed to morula stage or blastocyst stage was examined.

The results of the embryo culture in the two trials performed showed an increase from 43% to 68% (19 to 68%) morula formation in trial 1 (trial 2), i.e. on the whole the morula yield more than doubled in favor of culture in a 5% oxygen partial pressure compared with a 20% oxygen partial pressure.
Routine ultrasound screening in the third trimester: a population‐based study
Authors: Sylvan Kerstin , Ryding Elsa Lena , Rydhstroem Håkan
Published: November 2005

Background.  No population‐based study has evaluated the effects of third trimester ultrasound screening on prognosis.

Objective.  To study the effects of routine ultrasound screening in the third trimester on perinatal/infant mortality, prevalence of small for gestational age infants (SGA) and low Apgar score.

Study design.  Two university clinics using routine ultrasound screening in the third trimester were compared with seven county or district hospitals with no routine screening. Deliveries between 1985 and 1996 were included. In all, 16 municipalities including 56 371 pregnancies with routine screening were compared with 59 municipalities and 153 355 pregnancies without third trimester screening. An observational design was applied, using data stored during pregnancy, delivery, and during the first year (infant mortality) at the Swedish Medical Birth Registry, The National Board of Health and Welfare. Odds ratio with 95% confidence interval was used in the evaluation. End‐points included incidence of SGA, perinatal/infant mortality, Apgar score at 5 min, cesarean section and instrumental delivery in areas with versus without routine third trimester screening

Results.  No significant difference was seen in the prevalence of the most extreme SGA (< −3 SD from the mean), perinatal complications including cesarean section or instrumental delivery, or perinatal/infant mortality between units with versus without routine ultrasound screening in the third trimester.

Conclusion.  Added to the findings of previous small randomized studies, it seems as if routine third trimester ultrasound screening in an unselected population does not reduce perinatal mortality or early neonatal morbidity, expressed as Apgar scores or SGA.
Gestational diabetes: a reappraisal of HBA1c as a screening test
Authors: Agarwal Mukesh M. , Dhatt Gurdeep S. , Punnose John , Koster Gertrude
Published: November 2005

Background.  Recent technological advances have made HBA1c a more standardized and user‐friendly test with wide availability. This study evaluated HBA1c as a screening test for gestational diabetes mellitus (GDM) in a high‐risk population.

Methods.  A total of 442 pregnant women were assessed by HBA1c. Two thresholds were used to ‘rule in or rule out’ GDM, which was confirmed by the ‘gold‐standard’ 75‐g OGTT (World Health Organization criteria).

Results.  Eighty‐four (19%) women had GDM while 358 (81%) women were normal; there was a complete overlap of the HBA1c histograms of the two populations. The area under receiver operating characteristic curve of HBA1c to detect GDM was 0·54 (95% CI 0·48–0·61). Using a value of <5·5% to rule out GDM; a sensitivity of 82·1% was achieved, with 15 (16·7%) of 90 women below the threshold being false‐negatives (NPV = 83·3%). Using a threshold of HBA1c ≥ 7·5% to rule‐in GDM; the specificity was 95·8% with 15 (71·4%) of 21 patients over the threshold being false‐positives (PPV = 28·6%). HBA1c would eliminate the need for an OGTT in 25·1% (111/442) of whom 27% (30/111) women would be misclassified. At any HBA1c threshold with an acceptable sensitivity, the false‐positive rate remained high making it necessary for too many healthy women to undergo the confirmatory OGTT.

Conclusion.  Despite all the progress in methodology, HBA1c remains a poor test to screen for GDM.
Sympathetic responsibility in ethically difficult situations*
Authors: Danerek Margaretha , Udén Giggi , Dykes Anna‐Karin
Published: November 2005

Background. Ethical issues arise in many obstetric situations and demand constant consideration by obstetricians. The aim of this study was to highlight the meaning of being in an ethically difficult situation as narrated by obstetricians.

Methods. A descriptive design with a qualitative approach using a hermeneutic phenomenological method for analysis. Interviews were performed with 14 obstetricians working in a Swedish hospital setting.

Results. The overriding theme wasSympathetic responsibility in the decisions of critical importance for the mother and her infant. Five related themes were to: (i) proceed with a moral reasoning that leads to the choice of a possible solution; (ii) balance one's own medical knowledge and moral insight with the needs and requests of the parents; (iii) be aware of one's medical and moral responsibility in relation to the decision made; (iv) experience the ability to take action and to make and carry out difficult and important decisions relating to the health of the mother and infant; and (v) reflect on a given situation in a manner leading to a rational acceptance of one's own conduct.

Conclusions. Sympathetic responsibility is the structure of the meaning of the obstetricians' lived experience, which means that the obstetricians with the help of their medical knowledge and their desire to support the mother's autonomy do what is best for the mother and her infant. Implications include that an exchange of ethical thoughts and moral reasoning should lead to a higher degree of mutual understanding between colleagues and between the different professionals. Co‐operation is important to achieve the best outcome for the mother and her infant.
Response of pregnancy leg edema to a single immersion exercise session
Authors: Hartmann Sabine , Huch Renate
Published: November 2005

Background.  To quantify the effect of a single immersion exercise session on uncomplicated dependent edema in pregnancy.

Methods.  Lower leg volume was measured by water displacement volumetry and limb circumference in nine women with marked dependent edema, but otherwise normal second or third trimester pregnancy, before and after upright water immersion exercise session (Aqua‐Fit®) for 45 min. Maternal heart rate was monitored continuously throughout the session. Blood pressure was measured before and after the session.

Results.  Mean left leg volume decreased by 112 ml from 1665 to 1553 ml, and right leg volume by 84 ml from 1665 to 1581 ml (P = 0.007). Cardiovascular parameters fluctuated within the normal range, well below the upper limits recommended in pregnancy.

Conclusions.  A single immersion exercise session is a safe, effective, and enjoyable complement, or alternative, to compression stockings for reduction of gestational dependent edema. Further study is required to determine its duration of effect and the optimum interval between sessions.
Beat‐to‐beat estimate of fetal cardiac time intervals using magnetocardiography: longitudinal charts of normality ranges and individual trends
Authors: Comani Silvia , Liberati Marco , Mantini Dante , Merlino Biagio , Alleva Giovanna , Gabriele Elisabetta , Di Luzio Silvano , Romani Gian Luca
Published: November 2005

Background.  Fetal magnetocardiography (fMCG) records fetal cardiac electro‐physiological activity during the second half of gestation. We aimed at assessing normality values, related variability, and trends of fetal cardiac time intervals (fCTI) evaluated longitudinally from beat‐to‐beat fMCG analysis in uncomplicated pregnancies.

Materials and methods.  The fMCG were recorded with multi‐channel system in shielded room. FCTI were estimated on more than 2600 fetal cardiac cycles from 51 fMCG data sets of uncomplicated pregnancies. Independent component analysis (ICA) allowed reconstructing reliable fetal signals for beat‐to‐beat identification of fCTI (RR, P wave, PQ, PR, QT, QTc, QRS, ST, and T wave); intra‐individual variability analysis and trends were calculated; reference longitudinal charts accounted for intra‐ and inter‐individual variations and were compared with figures estimated on averaged signals.

Results.  For each data set, fCTI were calculated beat‐to‐beat on rhythm strips of more than 50 beats (95% overall detection rate). FCTI values, variability, and trends were in good agreement with available reference figures; intervals related to P and T waves were, respectively, underestimated and overestimated with respect to those estimated on averaged signals or obtained by other research groups. Errors were reduced and individual trends could be drawn.

Conclusions.  ICA permitted the reconstruction of reliable time course of fetal cardiac signals and the beat‐to‐beat calculation of time intervals, and normality ranges, with smaller errors with respect to previous studies. The retrieval of fetal traces with clear morphology and the longitudinal character of the study allowed estimating individual trends and beat‐to‐beat characterization, impossible with cross‐sectional studies on averaged beats.
In vitro fertilization in Sweden: maternal characteristics
Authors: Källén Bengt , Finnström Orvar , Nygren Karl‐Gösta , Otterblad Olausson Petra
Published: November 2005

Background.  Deliveries among women who had an in vitro fertilization (IVF) are characterized by increased risks for both the mother and the infant/child. Part of these effects may be due to maternal characteristics.

Methods.  Using reports from all clinics performing IVF in Sweden, 12 186 women who gave birth after such procedures were identified (13 261 deliveries, 16 280 infants born). Various social and medical characteristics of the women were studied and compared with all women giving birth. Information was retrieved by interviews in early pregnancy or by linkage with various registers.

Results.  Women who had IVF were older than other women who gave birth and were older after standard IVF than after intracytoplasmatic sperm injection (ICSI). They were more often of first parity and smoked less than other delivered women. There were more women with high body mass index: they worked outside home less often and were more often of Swedish nationality. Women who had standard IVF had more previous miscarriages than expected, but this was not true for women who had ICSI. Their pattern of drug usage differed from that of other women who had given birth.

Conclusions.  Women who underwent IVF and gave birth showed marked deviations from other women who gave birth. Some of these characteristics may help to explain the increased risks associated with these procedures. Women who had ICSI were less deviating than women who had standard IVF.
Matrix dimensionality in demographic analyses of plants: when to use smaller matrices?
Authors: Ramula Satu , Lehtilä Kari
Published: November 2005

Large data requirements may restrict the use of matrix population models for analysis of population dynamics. Less data are required for a small population matrix than for a large matrix because the smaller matrix contains fewer vital rates that need to be estimated. Smaller matrices, however, tend to have a lower precision. Based on 37 plant species, we studied the effects of matrix dimensionality on the long‐term population growth rate (λ) and the elasticity of λ in herbaceous and woody species. We found that when matrix dimensionality was reduced, changes in λ were significantly larger for herbaceous than for woody species. In many cases, λ of woody species remained virtually the same after a substantial decrease in matrix dimensionality, suggesting that woody species are less susceptible to matrix dimensionality. We demonstrated that when adjacent stages of a transition matrix are combined, the magnitude of a change in λ depends on the distance of the population structure from a stable stage distribution, and the difference in the combined vital rates weighted by their reproductive values. Elasticity of λ to survival and fecundity usually increased, whereas elasticity to growth decreased both in herbaceous and in woody species with reduced matrix dimensionality. Changes in elasticity values tended to be larger for herbaceous than for woody species. Our results show that by reducing matrix dimensionality, the amount of demographic data can be decreased to save time, money, and field effort. We recommend the use of a small matrix dimensionality especially when a limited amount of data is available, and for slow‐growing species having a simple matrix structure that mainly consists of stasis and growth to the next stage.
Effects of food stress and density in different life stages on reproduction in a butterfly
Authors: Bauerfeind Stephanie S. , Fischer Klaus
Published: November 2005

Availability of adequate nutrition and (rearing) density are among the most important factors affecting growth, development and reproduction in animals. In holometabolous insects diets and energetic needs change between life stages, with storing of larval resources, adult feeding and reproduction being linked strategies. Nevertheless, studies investigating nutritional (and density) effects across metamorphic boundaries are largely lacking. We aim at disentangling the functional basis of reproductive patterns by independently manipulating larval and adult (1) density and (2) access to food, respectively, in the tropical butterfly, Bicyclus anynana. (1) A high larval rearing density had, contrary to common wisdom, very little impact on body size, but reduced larval development time through increased growth rates. The latter is thought to be an adaptation to high densities, driven by the risk of larval food resources becoming exhausted before reaching metamorphosis. Larval density and male company during oviposition (i.e. adult density) had no detectable effects on female reproduction. (2) Larval food stress prolonged larval development time and reduced larval growth rate, body size, fecundity and reproductive investment. Detrimental effects on female reproduction were mediated through a reduction in body size. Additional negative effects of adult food stress on fecundity were largely confined to females being fed as larvae ad libitum, while those being previously starved showed reduced performance regardless of adult income. Effects on egg size were inconsistent and, overall, marginal. Our results show that restricted food access in different developmental stages may set different limits to reproduction, either posed by shortage of larval‐derived storage reserves (i.e. nitrogenous compounds) or adult income (i.e. carbohydrates). Thus, one should be cautious when stating that one or the other type of nutrients is ultimately limiting to reproduction. Rather, our findings highlight the importance of resource congruence and of considering both, larval‐ and adult‐derived resources for reproduction.
Greek Monetary Economics in Retrospect: The Adventures of the Drachma
Authors: Lazaretou Sophia
Published: November 2005

This paper enumerates the adventures of the drachma step by step, dividing its story into seven parts. Specifically, its main purpose is to present some historical perspective on the behaviour of the monetary and fiscal policies pursued in Greece during the period from the early 1830s until the introduction of the euro. For Greece, the lessons of historical experience are very important. Since the formation of the modern Greek state, government officials have striven – sometimes making hard efforts – to keep abreast of international monetary developments. This was because they understood that the participation of a peripheral, poor and inflation‐prone country with a weak currency and an underdeveloped money market, like Greece of the time, in a monetary club of powerful economies could improve her international credit standing and imply important benefits in terms of exchange rate and monetary stability, and long‐term foreign borrowing.
Integration or Independence? An Alternative Assessment of Real Interest Rate Linkages in the European Union
Authors: Holmes Mark J.
Published: November 2005

The relationship between national real interest rates provides a valuable insight into the extent of economic and financial integration between countries. This paper tests for long‐run parity in ex post real interest rates among the major European Union (EU) countries over the period 1979–2003. The empirical investigation, however, is based on an alternative approach. Strong parity is determined by whether or not the first largest principal component (LPC), based on real interest rate differentials with respect to a chosen base country, is stationary. The qualitative outcome of the test is invariant to the choice of base country, and compared with alternative multivariate tests for long‐run parity, this methodology places less demands on limited data sets. Strong evidence of onshore parity occurs during 1979–1990 and 1993–2003 with the half‐life of a deviation to parity that varies towards 6 months. There is no evidence of long‐run parity among EU members during 1990–1993 despite the easing of remaining capital controls in 1990. Parity is rejected for a sample of non‐EU countries throughout the study period.
Examining user acceptance of computer technology: an empirical study of student teachers
Authors: Ma Will Wai‐kit , Andersson Robert , Streith Karl‐Oskar
Published: November 2005

Abstract
The use of computer technology in schools has made slow progress since the mid‐1980s even though governments have been generous in funding. It is therefore important to understand how and when teachers use computer technology in order to devise implementation strategies to encourage them. This study investigates student teachers' perceptions of computer technology in relation to their intention to use computers. The purpose is to shed light on more effective ways to motivate the use of computer technology in schools. Based on an expanded variation of the Technology Acceptance Model, 84 completed surveys of student teachers were collected at a local university in Sweden. Overall, the results indicated that (1) student teachers' perceived usefulness of computer technology had a direct significant effect on their intention to use it; (2) student teachers' perceived ease of use had only an indirect significant effect on intention to use; however, (3) student teachers' subjective norm, that is the possible influence of external expectations, did not have any direct or indirect significant effects on their intention to use computer technology. Theoretical and practical implications that follow from the results are discussed.