bluuebunny/crossref_metadata_2025 huggingface dataset:
𝐶*-isomorphisms, Jordan isomorphisms, and numerical range preserving maps
Authors: Gau Hwa-Long , Li Chi-Kwong
Published: May 2007

Let

V

=
B
(
H
)

\mathbf V = B(H)

or

S
(
H
)

S(H)

, where

B
(
H
)

B(H)

is the algebra of a bounded linear operator acting on the Hilbert space

H
H

, and

S
(
H
)

S(H)

is the set of self-adjoint operators in

B
(
H
)

B(H)

. Denote the numerical range of

A
∈
B
(
H
)

A \in B(H)

by

W
(
A
)
=
{

(
A
x
,
x
)
:
x
∈
H
,
(
x
,
x
)
=
1

}

W(A) = \{\, (Ax,x): x \in H, (x,x) = 1\,\}

. It is shown that a surjective map

ϕ
:

V

→

V

\phi : \mathbf V \rightarrow \mathbf V

satisfies
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper W left-parenthesis upper A upper B plus upper B upper A right-parenthesis equals upper W left-parenthesis phi left-parenthesis upper A right-parenthesis phi left-parenthesis upper B right-parenthesis plus phi left-parenthesis upper B right-parenthesis phi left-parenthesis upper A right-parenthesis right-parenthesis for all upper A comma upper B element-of bold upper V">

W
(
A
B
+
B
A
)
=
W
(
ϕ
(
A
)
ϕ
(
B
)
+
ϕ
(
B
)
ϕ
(
A
)
)

for all 

A

, 

B
∈

V

W(AB+BA) = W(\phi (A)\phi (B)+\phi (B)\phi (A)) \qquad \text {for all $A$, $B \in \mathbf {V}$}

\]
if and only if there is a unitary operator

U
∈
B
(
H
)

U \in B(H)

such that

ϕ
\phi

has the form
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper X right-arrow from bar plus-or-minus upper U Superscript asterisk Baseline upper X upper U normal o normal r upper X right-arrow from bar plus-or-minus upper U Superscript asterisk Baseline upper X Superscript t Baseline upper U comma">

X
↦
±

U
∗

X
U

o
r

X
↦
±

U
∗

X
t

U
,

X \mapsto \pm U^*XU \quad \mathrm {or} \quad X \mapsto \pm U^*X^tU,

\]
where

X
t

X^t

is the transpose of

X
X

with respect to a fixed orthonormal basis. In other words, the map

ϕ
\phi

or

−
ϕ

-\phi

is a

C
∗

C^*

-isomorphism on

B
(
H
)

B(H)

and a Jordan isomorphism on

S
(
H
)

S(H)

. Moreover, if

H
H

has finite dimension, then the surjective assumption on

ϕ
\phi

can be removed.
Special subsets of the reals and tree forcing notions
Authors: Kysiak Marcin , Nowik Andrzej , Weiss Tomasz
Published: May 2007

We study relationships between classes of special subsets of the reals (e.g. meager-additive sets,

γ
\gamma

-sets,

C
C

-sets,

λ
\lambda

-sets) and the ideals related to the forcing notions of Laver, Mathias, Miller and Silver.
Level algebras with bad properties
Authors: Boij Mats , Zanello Fabrizio
Published: May 2007

This paper can be seen as a continuation of the works contained in the recent article (J. Alg., 305 (2006), 949–956) of the second author, and those of Juan Migliore (math. AC/0508067). Our results are: 1). There exist codimension three artinian level algebras of type two which do not enjoy the Weak Lefschetz Property (WLP). In fact, for

e
≫
0

e\gg 0

, we will construct a codimension three, type two

h
h

-vector of socle degree

e
e

such that all the level algebras with that

h
h

-vector do not have the WLP. We will also describe the family of those algebras and compute its dimension, for each

e
≫
0

e\gg 0

. 2). There exist reduced level sets of points in

P

3

{\mathbf P}^3

of type two whose artinian reductions all fail to have the WLP. Indeed, the examples constructed here have the same

h
h

-vectors we mentioned in 1). 3). For any integer

r
≥
3

r\geq 3

, there exist non-unimodal monomial artinian level algebras of codimension

r
r

. As an immediate consequence of this result, we obtain another proof of the fact (first shown by Migliore in the above-mentioned preprint, Theorem 4.3) that, for any

r
≥
3

r\geq 3

, there exist reduced level sets of points in

P

r

{\mathbf P}^r

whose artinian reductions are non-unimodal.
Characters of association schemes containing a strongly normal closed subset of prime index
Authors: Hanaki Akihide
Published: May 2007

We consider a relation between characters of an association scheme and its strongly normal closed subsets with prime index. As an application of our result, we show that an association scheme of prime square order with a proper strongly normal closed subset is commutative.
Discovering gene expression patterns in time course microarray experiments by ANOVA–SCA
Authors: Nueda María José , Conesa Ana , Westerhuis Johan A. , Hoefsloot Huub C. J. , Smilde Age K. , Talón Manuel , Ferrer Alberto
Published: May 2007

Motivation: Designed microarray experiments are used to investigate the effects that controlled experimental factors have on gene expression and learn about the transcriptional responses associated with external variables. In these datasets, signals of interest coexist with varying sources of unwanted noise in a framework of (co)relation among the measured variables and with the different levels of the studied factors. Discovering experimentally relevant transcriptional changes require methodologies that take all these elements into account.

Results: In this work, we develop the application of the Analysis of variance–simultaneous component analysis (ANOVA–SCA) Smilde et al. Bioinformatics, (2005) to the analysis of multiple series time course microarray data as an example of multifactorial gene expression profiling experiments. We denoted this implementation as ASCA-genes. We show how the combination of ANOVA-modeling and a dimension reduction technique is effective in extracting targeted signals from data by-passing structural noise. The methodology is valuable for identifying main and secondary responses associated with the experimental factors and spotting relevant experimental conditions. We additionally propose a novel approach for gene selection in the context of the relation of individual transcriptional patterns to global gene expression signals. We demonstrate the methodology on both real and synthetic datasets.

Availability: ASCA-genes has been implemented in the statistical language R and is available at http://www.ivia.es/centrodegenomica/bioinformatics.htm.

Contact:  mj.nueda@ua.es and aconesa@cipf.es

Supplementary information: Supplementary data are available at Bioinformatics online.
Adverse Patient Occurrences in Otorhinolaryngology: Results of a Systematic Registry in a Tertiary Referral Hospital
Authors: Hoffmans Ruth , Stokroos Robert J. , Rikers Mircea , Kingma Herman , Kremer Bernd
Published: May 2007

Objective: To identify patient groups at risk for Adverse Patient Occurrences (APOs) to improve the quality of care.

Study Design: This study was conducted using retrospective analysis.

Methods: APOs have been systematically registered from 1997 to 2006 in all patients (6,932) admitted to the otorhinolaryngology–head and neck surgery department of the University Hospital Maastricht, the Netherlands. Several characteristics such as length of stay, age, gender, season, and diagnosis were related to the incidence and type of APOs.

Results: Increasing age and length of stay are related to an increasing incidence of APOs. Children are found to be at high risk too and outpatient treatment (<24 h) is a risk factor for APOs. Of all APOs, 67% were organizational and 33% medical. The three diagnosis‐related groups (DRGs), in which APOs occurred most, were the inner ear/cerebellopontine angle (CPA), esophagus, and head and neck oncology group. No seasonal influences on APO occurrences existed.

Conclusions: Male and female patients >60 or <10 years old are at the highest risk for APOs. Their risk increases with their length of stay and is high when admitted less than 24 hours. When patients are among the three most prevalent DRGs, their risk is even higher.
Long‐Term Efficacy of Sublingual Immunotherapy in Patients With Perennial Rhinitis
Authors: Tahamiler Rauf , Saritzali Gkioukxel , Canakcioglu Salih
Published: May 2007

Background: Sublingual immunotherapy has a documented clinical efficacy, but only a few long‐term studies have been performed in people with perennial rhinitis.

Objectives: The purpose of this study was to evaluate the long‐term efficacy of sublingual immunotherapy.

Methods: One hundred thirty‐seven patients with allergies to house dust mites were treated with sublingual house dust‐mite‐specific immunotherapy for 2 or 3 years and were also observed for 3 years after discontinuation of the treatment. The patients were divided into 2 groups: group A (67 patients) received active treatment for 2 years and then 1 year for placebo, and group B (70 patients) received active treatment for 3 years. The success of the treatment was evaluated with the symptom score, skin prick test results, and the nasal allergen challenge score.

Results: According to our study results, we found a greater improvement in the 3 years of sublingual immunotherapy compared with the 2 years of sublingual immunotherapy when we looked at the comparative results of the total 6 years.

Conclusion: We suggest 3 years of sublingual immunotherapy for patients with perennial allergic rhinitis who require immunotherapy and do not accept the subcutaneous route of allergen administration.
A catchment-scale carbon and greenhouse gas budget of a subarctic landscape
Authors: Christensen T.R , Johansson T , Olsrud M , Ström L , Lindroth A , Mastepanov M , Malmer N , Friborg T , Crill P , Callaghan T.V
Published: May 2007

This is the first attempt to budget average current annual carbon (C) and associated greenhouse gas (GHG) exchanges and transfers in a subarctic landscape, the Lake Torneträsk catchment in northern Sweden. This is a heterogeneous area consisting of almost 4000 km2of mixed heath, birch and pine forest, and mires, lakes and alpine ecosystems. The magnitudes of atmospheric exchange of carbon in the form of the GHGs, CO2and CH4in these various ecosystems differ significantly, ranging from little or no flux in barren ecosystems over a small CO2sink function and low rates of CH4exchange in the heaths to significant CO2uptake in the forests and also large emissions of CH4from the mires and small lakes. The overall catchment budget, given the size distribution of the individual ecosystem types and a first approximation of run-off as dissolved organic carbon, reveals a landscape currently with a significant sink capacity for atmospheric CO2. This sink capacity is, however, extremely sensitive to environmental changes, particularly those that affect the birch forest ecosystem. Climatic drying or wetting and episodic events such as insect outbreaks may cause significant changes in the sink function. Changes in the sources of CH4through increased permafrost melting may also easily change the sign of the current radiative forcing, due to the stronger impact per gram of CH4relative to CO2. Hence, to access impacts on climate, the atmospheric C balance alone has to be weighed in a radiative forcing perspective. When considering the emissions of CH4from the mires and lakes as CO2equivalents, the Torneträsk catchment is currently a smaller sink of radiative forcing, but it can still be estimated as representing the equivalent of approximately 14 000 average Swedish inhabitants' emissions of CO2. This can be compared with the carbon emissions of less than 200 people who live permanently in the catchment, although this comparison disregards substantial emissions from the non-Swedish tourism and transportation activities.
Lifetimes and time scales in atmospheric chemistry
Authors: Prather Michael J
Published: May 2007

Atmospheric composition is controlled by the emission, photochemistry and transport of many trace gases. Understanding the time scale as well as the chemical and spatial patterns of perturbations to trace gases is needed to evaluate possible environmental damage (e.g. stratospheric ozone depletion or climate change) caused by anthropogenic emissions. This paper reviews lessons learned from treating global atmospheric chemistry as a linearized system and analysing it in terms of eigenvalues.

The results give insight into how emissions of one trace species cause perturbations to another and how transport and chemistry can alter the time scale of the overall perturbation. Further, the eigenvectors describe the fundamental chemical modes, or patterns, of the atmosphere's chemical response to perturbations.
Constraining past global tropospheric methane budgets with carbon and hydrogen isotope ratios in ice
Authors: Whiticar Michael , Schaefer Hinrich
Published: May 2007

Upon closer inspection, the classical view of the synchronous relationship between tropospheric methane mixing ratio and Greenland temperature observed in ice samples reveals clearly discernable variations in the magnitude of this response during the Late Pleistocene (<50 kyr BP). During the Holocene this relationship appears to decouple, indicating that other factors have modulated the methane budget in the past 10 kyr BP. The δ
13
CH
4
and δD-CH
4
of tropospheric methane recorded in ice samples provide a useful constraint on the palaeomethane budget estimations. Anticipated changes in palaeoenvironmental conditions are recorded as changes in the isotope signals of the methane precursors, which are then translated into past global δ
13
CH
4
and δD-CH
4
signatures. We present the first methane budgets for the late glacial period that are constrained by dual stable isotopes. The overall isotope variations indicate that the Younger Dryas (YD) and Preindustrial Holocene have methane that is
13
C- and
2
H-enriched, relative to Modern. The shift is small for δ
13
CH
4
(approx. 1‰) but greater for δD-CH
4
(approx. 9‰). The YD δ
13
CH
4
–δD-CH
4
record shows a remarkable relationship between them from 12.15 to 11.52 kyr BP. The corresponding C- and H-isotope mass balances possibly indicate fluctuating emissions of thermogenic gas. This δ
13
CH
4
–δD-CH
4
relationship breaks down during the YD–Preboreal transition. In both age cases, catastrophic releases of hydrates with Archaeal isotope signatures can be ruled out. Thermogenic clathrate releases are possible during the YD period, but so are conventional natural gas seepages.
Ozone and life on the Archaean Earth
Authors: Cockell Charles S , Raven John A
Published: May 2007

The trace gas ozone, produced in the present-day stratosphere, acts as a screen for UV radiation between 195 and approximately 290 nm, depending on its column abundance. On the anoxic Archaean Earth, such an ozone screen would not have existed. Although the presence of other screens, such as an organic haze, might have ameliorated the UV radiation flux, even assuming the worst-case scenario (no UV screen), it can be shown that early land masses and the photic zone of the oceans could have been colonized, suggesting that: (i) high UV radiation would not have prevented the colonization of land and (ii) it is unlikely that the fossil record can be used to constrain estimates of the UV radiation environment of the early Earth (although geochemical approaches and the study of extrasolar planetary atmospheres are likely to provide empirical constraints on the early photobiological environment).
Diversity and genomics of Antarctic marine micro-organisms
Authors: Murray Alison E , Grzymski Joseph J
Published: May 2007

Marine bacterioplanktons are thought to play a vital role in Southern Ocean ecology and ecosystem function, as they do in other ocean systems. However, our understanding of phylogenetic diversity, genome-enabled capabilities and specific adaptations to this persistently cold environment is limited. Bacterioplankton community composition shifts significantly over the annual cycle as sea ice melts and phytoplankton bloom. Microbial diversity in sea ice is better known than that of the plankton, where culture collections do not appear to represent organisms detected with molecular surveys. Broad phylogenetic groupings of Antarctic bacterioplankton such as the marine group I Crenarchaeota, α-Proteobacteria (
Roseobacter
-related and SAR-11 clusters), γ-Proteobacteria (both cultivated and uncultivated groups) and Bacteriodetes-affiliated organisms in Southern Ocean waters are in common with other ocean systems. Antarctic SSU rRNA gene phylotypes are typically affiliated with other polar sequences. Some species such as
Polaribacter irgensii
and currently uncultivated γ-Proteobacteria (Ant4D3 and Ant10A4) may flourish in Antarctic waters, though further studies are needed to address diversity on a larger scale. Insights from initial genomics studies on both cultivated organisms and genomes accessed through shotgun cloning of environmental samples suggest that there are many unique features of these organisms that facilitate survival in high-latitude, persistently cold environments.
Evolution and biodiversity of Antarctic organisms: a molecular perspective
Authors: Rogers Alex David
Published: May 2007

The Antarctic biota is highly endemic, and the diversity and abundance of taxonomic groups differ from elsewhere in the world. Such characteristics have resulted from evolution in isolation in an increasingly extreme environment over the last 100 Myr. Studies on Antarctic species represent some of the best examples of natural selection at the molecular, structural and physiological levels. Analyses of molecular genetics data are consistent with the diversity and distribution of marine and terrestrial taxa having been strongly influenced by geological and climatic cooling events over the last 70 Myr. Such events have resulted in vicariance driven by continental drift and thermal isolation of the Antarctic, and in pulses of species range contraction into refugia and subsequent expansion and secondary contact of genetically distinct populations or sister species during cycles of glaciation. Limited habitat availability has played a major role in structuring populations of species both in the past and in the present day. For these reasons, despite the apparent simplicity or homogeneity of Antarctic terrestrial and marine environments, populations of species are often geographically structured into genetically distinct lineages. In some cases, genetic studies have revealed that species defined by morphological characters are complexes of cryptic or sibling species. Climate change will cause changes in the distribution of many Antarctic and sub-Antarctic species through affecting population-level processes such as life history and dispersal.
The effect of temperature and thermal acclimation on the sustainable performance of swimming scup
Authors: Rome Lawrence C
Published: May 2007

There is a significant reduction in overall maximum power output of muscle at low temperatures due to reduced steady-state (i.e. maximum activation) power-generating capabilities of muscle. However, during cyclical locomotion, a further reduction in power is due to the interplay between non-steady-state contractile properties of muscle (i.e. rates of activation and relaxation) and the stimulation and the length-change pattern muscle undergoesin vivo. In particular, even though the relaxation rate of scup red muscle is slowed greatly at cold temperatures (10°C), warm-acclimated scup swim with the same stimulus duty cycles at cold as they do at warm temperature, not affording slow-relaxing muscle any additional time to relax. Hence, at 10°C, red muscle generates extremely low or negative work in most parts of the body, at all but the slowest swimming speeds.

Do scup shorten their stimulation duration and increase muscle relaxation rate during cold acclimation? At 10°C, electromyography (EMG) duty cycles were 18% shorter in cold-acclimated scup than in warm-acclimated scup. But contrary to the expectations, the red muscle did not have a faster relaxation rate, rather, cold-acclimated muscle had an approximately 50% faster activation rate. By driving cold- and warm-acclimated muscle through cold- and warm-acclimated conditions, we found a very large increase in red muscle power during swimming at 10°C. As expected, reducing stimulation duration markedly increased power output. However, the increased rate of activation alone produced an even greater effect. Hence, to fully understand thermal acclimation, it is necessary to examine the whole system under realistic physiological conditions.
Cardiorespiratory performance during prolonged swimming tests with salmonids: a perspective on temperature effects and potential analytical pitfalls
Authors: Farrell A.P
Published: May 2007

A prolonged swimming trial is the most common approach in studying steady-state changes in oxygen uptake, cardiac output and tissue oxygen extraction as a function of swimming speed in salmonids. The data generated by these sorts of studies are used here to support the idea that a maximum oxygen uptake is reached during a critical swimming speed test. Maximum oxygen uptake has a temperature optimum. Potential explanations are advanced to explain why maximum aerobic performance falls off at high temperature. The valuable information provided by critical swimming tests can be confounded by non-steady-state swimming behaviours, which typically occur with increasing frequency as salmonids approach fatigue. Two major concerns are noted. Foremost, measurements of oxygen uptake during swimming can considerably underestimate the true cost of transport near critical swimming speed, apparently in a temperature-dependent manner. Second, based on a comparison with voluntary swimming ascents in a raceway, forced swimming trials in a swim tunnel respirometer may underestimate critical swimming speed, possibly because fish in a swim tunnel respirometer are unable to sustain a ground speed.
The thalamus of the monotremes: cyto- and myeloarchitecture and chemical neuroanatomy
Authors: Mikula Shawn , Manger Paul R , Jones Edward G
Published: May 2007

Echidna and platypus brains were sectioned and stained by Nissl or myelin stains or immunocytochemically for calcium-binding proteins, gamma aminobutyric acid (GABA) or other antigens. Cyto- and myeloarchitecture revealed thalami that are fundamentally mammalian in organization, with the three principal divisions of the thalamus (epithalamus, dorsal thalamus and ventral thalamus) identifiable as in marsupials and eutherian mammals. The dorsal thalamus exhibits more nuclear parcellation than hitherto described, but lack of an internal medullary lamina, caused by splaying out of afferent fibre tracts that contribute to it in other mammals, makes identification of anterior, medial and intralaminar nuclear groups difficult. Differentiation of the ventral nuclei is evident with the ventral posterior nucleus of the platypus enormously expanded into the interior of the cerebral hemisphere, where it adopts a relationship to the striatum not seen in other mammals. Other nuclei such as the lateral dorsal become identifiable by expression of patterns of calcium-binding proteins identical to those found in other mammals. GABA cells are present in the ventral and dorsal thalamic nuclei, and in the ventral thalamus form a remarkable continuum with GABA cells of the two segments of the globus pallidus and pars reticulata of the substantia nigra.
The impact of strategic funding by the tobacco industry of medical expert witnesses appearing for the defence in the Aho Finnish product liability case
Authors: Hiilamo Heikki T.
Published: May 2007

Aims  To identify and evaluate tobacco industry strategies to recruit medical expert witnesses.

Methods  A systematic search was made of internal tobacco industry documents available on the Internet and at British American Tobacco Guildford Depository. Litigation by a plaintiff with laryngeal cancer against the tobacco industry in Finland was used as a case study of tobacco industry strategies to manipulate science and its use and deployment in defending a product liability claim.

Results  Thirty‐three of 45 medical expert witnesses for the defence received research funding before or after testifying. One strategy was to employ those scientists as witnesses with whom the industry had worked since the 1960s. The older witnesses testified to the existence of a controversy which they had, in fact, helped to create. Those appearing in Helsinki District court apparently downplayed the importance of their involvement with the industry. Another strategy was the use of research funding to establish contacts with new potential witnesses, to strengthen existing contacts or to pay back helpful experts.

Conclusions  The tobacco industry funded the majority of expert witnesses appearing for it, beyond simple recompense for the time involved. This may have unconsciously influenced the testimony given by the witnesses. This funding should be considered in court, but links between experts and the industry were often downplayed or, in some cases, the financial ties were being forged at the time and were not revealed. It would be helpful to establish norms to guide courts to understand the influences exerted by the tobacco industry in the preparation of cases requiring expert evidence.
Implicit learning, executive function and hedonic activity in chronic polydrug abusers, currently abstinent polydrug abusers and controls
Authors: Stevens Andreas , Peschk Ines , Schwarz Jürgen
Published: May 2007

Aims  The study seeks to evaluate impairments of implicit learning and executive function in chronic polydrug abusers. It was hypothesized that implicit learning and executive function correlate with anhedonia.

Design  A cross‐sectional group comparison.

Settings  Department of Psychiatry, University of Tübingen, Germany.

Participants  A total of 25 male polydrug abusers with opiate dependence, n = 26 polydrug abusers abstinent for more than 3 months and n = 26 non‐drug‐using healthy males.

Setting  Abstinent polydrug abusers were recruited from a community treatment centre, current polydrug abusers from local drug counselling services and controls through advertisements.

Measurements  A psychological battery assessing implicit learning (serial reaction‐time task), various executive functions (latent inhibition, delayed matching‐to‐sample, Trail Making Test, acquisition and modification of conditioned responses, figural reasoning) and verbal logic memory was administered. Hedonic thoughts and activities as well as depressive symptoms were assessed through questionnaires.

Findings  In chronic polydrug abusers, there were moderate impairments of implicit learning, of acquisition, reversal and extinction of conditioned responses, of latent inhibition as well as anhedonia, while working memory was spared. In the abstinent group, cognitive performance was normal except for latent inhibition and more anhedonia and depression than in controls.

Conclusions  The findings suggest that current polydrug abusers suffer from impairment of many cognitive functions and from anhedonia. During abstinence, there is near normal cognitive function but still anhedonia. Anhedonia was correlated with implicit learning but not with executive function.
Acute effects of a guided relaxation routine (body scan) on tobacco withdrawal symptoms and cravings in abstinent smokers
Authors: Cropley Mark , Ussher Michael , Charitou Elli
Published: May 2007

Aims  To examine the acute effects of a guided relaxation routine (body scan) on desire to smoke and tobacco withdrawal symptoms in overnight abstinent smokers.

Design  Experimental.

Participants  Thirty individuals reporting to smoke 10 or more cigarettes daily for at least 3 years.

Intervention  Participants were assigned randomly to complete a 10‐minute body scan (experimental group n = 15) or listen to a natural history passage for 10 minutes (control group n = 15).

Measurement  Ratings of strength of desire to smoke and smoking withdrawal symptoms were assessed at baseline, immediately after the interventions, and 5, 10 and 15 minutes post‐intervention.

Findings  There was a significant group × time interaction for strength of desire to smoke. The mean desire to smoke rating was significantly lower in the body scan group relative to the control group immediately after the intervention, and 5 minutes post‐intervention. The body scan group also reported lower ratings of irritability, tension and restlessness, relative to the controls.

Conclusion  A brief body scan intervention reduces strength of desire to smoke and some tobacco withdrawal symptoms in temporarily abstaining smokers. The body scan may be beneficial as a technique for managing cigarette cravings and withdrawal.
Factors associated with pathological gambling at 10‐year follow‐up in a national sample of middle‐aged men
Authors: Scherrer Jeffrey F. , Slutske Wendy S. , Xian Hong , Waterman Brian , Shah Kamini R. , Volberg Rachel , Eisen Seth A.
Published: May 2007

Background  The present analyses will expand on previous reports by considering the impact of eight psychiatric disorders and genetic vulnerability to problem (P) and pathological gambling gambling (PG).

Methods  Diagnoses of DSM‐III‐R life‐time P and PG were derived in 1992 and past‐year P and PG in 2002 from 1675 individual twins from the Vietnam Era Twin Registry. Logistic regression was used to predict past‐year P and PG as a function of socio‐demographics and life‐time co‐occurring psychiatric disorders including gambling problems measured in 1992. Co‐twin analyses accounted for familial contributions to past‐year gambling problems.

Results  High school or greater educational attainment was associated with less likelihood of current P and PG. With the exception of alcohol dependence and generalized anxiety/panic, all disorders studied remained associated significantly with an increase risk of past‐year P and PG after adjusting for 1992 gambling symptoms. Past‐year P and PG was associated significantly with the number of pathological gambling symptoms reported in 1992. After controlling for genetic and family environmental factors, one or more 1992 symptoms were associated with 2002 symptoms.

Conclusions  Education and substance dependence, mood and antisocial personality disorders were associated with current gambling. A history of PG symptoms is the strongest predictor of past‐year problem gambling.
Cognitive impairment in Aboriginal people with heavy episodic patterns of alcohol use
Authors: Cairney Sheree , Clough Alan , Jaragba Muriel , Maruff Paul
Published: May 2007

Background  With chronic alcohol abuse, cognitive studies suggest that progressive cognitive decline may precede more serious and irreversible neurological syndromes. The early detection of cognitive impairment may therefore aid in the prevention of permanent brain damage. Despite the devastating consequences of alcohol abuse among Aboriginal Australians, the effects on brain function have never been studied in this population and a lack of appropriate assessment tools has prevented the development of such research.

Aims  To determine the impact of long‐term and heavy episodic alcohol use on cognitive function in Aboriginal people.

Design  Cross‐sectional comparing heavy episodic alcohol users with non‐alcohol users.

Setting  Two remote Aboriginal communities in north‐east Arnhem Land, northern Australia.

Subjects  The control group consisted of 24 non‐drinkers (15 males, nine female) and the heavy episodic group consisted of 20 people (19 males, one female) who had been drinking alcohol in a heavy episodic style (median 14 drinks per occasion) for a mean of 8.9 years (SD = 5.0).

Measurements  Interview to obtain demographic information, substance abuse history and symptoms of mental health and wellbeing, together with a computerized cognitive assessment battery (CogState Ltd).

Findings  Compared with non‐drinkers, heavy episodic drinkers showed reduced psychomotor speed (P = 0.04) and reduced accuracy when performing tasks of attention (P = 0.045), working memory (P = 0.04), implicit memory (P = 0.03) and associate learning and memory (P = 0.001).

Conclusions  Specific cognitive abnormalities that suggest frontostriatal abnormalities and have been observed in association with chronic alcoholism in other populations were observed among Aboriginal Australians who were heavy episodic alcoholic users.
Inhibition of platelet‐derived growth factor receptorβ by imatinib mesylate suppresses proliferation and alters differentiation of human mesenchymal stem cells in vitro
Authors: Fierro F. , Illmer T. , Jing D. , Schleyer E. , Ehninger G. , Boxberger S. , Bornhäuser M.
Published: May 2007

Abstract.  Objectives: Recent data show that Imatinib mesylate (IM) also affects haematopoietic stem cells (HSC), T lymphocytes and dendritic cells that do not harbour constitutively active tyrosine kinases. Materials and methods: We evaluated possible effects of IM on human bone marrow‐derived mesenchymal stem cells (MSC) in vitro. Results: Screening the activity of 42 receptor tyrosine kinases revealed an exclusive inhibition of platelet‐derived growth factor receptorβ (PDGFRβ). Analysis of downstream targets of PDGFRβ demonstrated IM‐mediated reduction of Akt and Erk1/2 phosphorylation. Culture of MSC with IM led to the reversible development of perinuclear multi‐vesicular bodies. The proliferation and clonogenicity of MSC were significantly reduced compared to control cultures. IM favoured adipogenic differentiation of MSC whereas osteogenesis was suppressed. The functional deficits described led to a 50% reduction in the support of clonogenic haematopoietic stem cells, cultured for 1 month on a monolayer of MSC with IM. Conclusion: In summary, inhibition of PDGFRβ and downstream Akt and Erk signalling by IM has a significant impact on proliferation and differentiation of human MSC in vitro.
BubR1 deficiency results in enhanced activation of MEK and ERKs upon microtubule stresses
Authors: Yang Y. L. , Duan Q. , Guo T. B. , Wang X. X. , Ruan Q. , Xu G. T. , Zhang J. W. , Lu Z. Y. , Xu M. , Lu L. , Dai W.
Published: May 2007

Abstract.  Disruption of microtubules activates the spindle checkpoint, of which BubR1 is a major component. Our early studies show that BubR1 haplo‐insufficiency results in enhanced mitotic slippage in vitro and tumorigenesis in vivo. Objective: Given that both MAPKs/ERKs and MEK play an important role during mitosis, we investigated whether there existed regulatory relationship between the MAPK signalling pathway and BubR1. Method and Results: Here, we have demonstrated that BubR1 deficiency is correlated with enhanced activation of MEK and ERKs after disruption of microtubule dynamics. Specifically, treatment with nocodazole and paclitaxel resulted in hyper‐activation of ERKs and MEK in BubR1+/– murine embryonic fibroblasts (MEF) compared to that of wild‐type MEFs. This enhanced activation of ERKs and MEK was at least partly responsible for more successful proliferation completion when cells were treated with nocodazole. BubR1 knockdown via RNAi resulted in enhanced activation of ERKs and MEK in HeLa cells, correlating with inhibition of PP1, a negative regulator of MEK. Moreover, when BubR1 was partially inactivated due to premature missegregation of chromosomes after Sgo1 depletion, phosphorylation of ERKs and MEK was enhanced in mitotic cells; in contrast, little, if any activated ERKs and MEK were detected in mitotic cells induced by nocodazole. Furthermore, BubR1, activated ERKs and activated MEK all localized to spindle poles during mitosis, and also, the proteins physically interacted with each other. Conclusion: Our studies suggest that there exists a cross‐talk between spindle checkpoint components and ERKs and MEK and that BubR1 may play an important role in mediating the cross‐talk.
Contemporary evolution of secondary sexual traits in the wild
Authors: SVENSSON E. I. , GOSDEN T. P.
Published: May 2007

Sexual selection has been studied intensively, and is often strong in natural populations. Theoretical models, comparative studies and laboratory selection experiments all suggest that evolution driven by sexual selection should be rapid and common.

However, there are relatively few documented cases of the contemporary evolution of secondary sexual traits in natural populations. Moreover, the causes are not always due to sexual selection, but often due to altered natural selection regimes, or an altered balance between natural and sexual selection.

Here we discuss recent empirical studies that have demonstrated the contemporary evolution of secondary sexual traits in natural populations. Our examples include both continuous traits and discrete polymorphisms. Taxa in which the contemporary (rapid) evolution of secondary sexual traits have been demonstrated include fish, insects, mammals, reptiles and birds. The evolutionary rates of these changes range from 0·005 to 0·570 haldanes (arithmetic mean = 0·14; geometric mean = 0·095; median = 0·12).

The relative rarity of examples could be explained by different genetic architectures of sexually selected traits compared with naturally selected traits, or by sexual selection regimes not being sustained in the long term. These factors could potentially slow down evolutionary rates of secondary sexual traits and make the detection of the contemporary evolution empirically more difficult.

Promising and underutilized approaches to sexual selection research include reciprocal transplant experiments and estimation of sexual isolation between conspecific populations.
Evolution on ecological time‐scales
Authors: CARROLL S. P. , HENDRY A. P. , REZNICK D. N. , FOX C. W.
Published: May 2007

Ecologically significant evolutionary change, occurring over tens of generations or fewer, is now widely documented in nature. These findings counter the long‐standing assumption that ecological and evolutionary processes occur on different time‐scales, and thus that the study of ecological processes can safely assume evolutionary stasis. Recognition that substantial evolution occurs on ecological time‐scales dissolves this dichotomy and provides new opportunities for integrative approaches to pressing questions in many fields of biology.

The goals of this special feature are twofold: to consider the factors that influence evolution on ecological time‐scales – phenotypic plasticity, maternal effects, sexual selection, and gene flow – and to assess the consequences of such evolution – for population persistence, speciation, community dynamics, and ecosystem function.

The role of evolution in ecological processes is expected to be largest for traits that change most quickly and for traits that most strongly influence ecological interactions. Understanding this fine‐scale interplay of ecological and evolutionary factors will require a new class of eco‐evolutionary dynamic modelling.

Contemporary evolution occurs in a wide diversity of ecological contexts, but appears to be especially common in response to anthropogenic changes in selection and population structure. Evolutionary biology may thus offer substantial insight to many conservation issues arising from global change.

Recent studies suggest that fluctuating selection and associated periods of contemporary evolution are the norm rather than exception throughout the history of life on earth. The consequences of contemporary evolution for population dynamics and ecological interactions are likely ubiquitous in time and space.
Primary malignancies mistaken for pseudotumours in haemophilic patients
Authors: ALLEN D. J. , GODDARD N. J. , MANN H. A. , RODRIGUEZ‐MERCHAN E. C.
Published: May 2007

Summary.  Pseudotumours are a rare complication of haemophilia. Surgery undertaken for pseudotumour on a lesion that is subsequently found to be malignant can be expected to adversely affect patient outcome. We present six case reports found from a literature search of patients with haemophilia who underwent surgery on what was a primary malignancy misdiagnosed as a pseudotumour and give a subsequent discussion.
Fracture neck of femur in haemophilia A – experience from a cohort of 11 patients from a tertiary centre in India
Authors: LEE V. N. , SRIVASTAVA A. , NITHYANANTH M. , KUMAR P. , CHERIAN V. M. , VISWABANDYA A. , MATHEWS V. , GEORGE B. , VENKATESH K , NAIR S. C. , CHANDY M. , SUNDARARAJ G. D.
Published: May 2007

Summary.  We describe here the management of eleven patients with fracture neck of femur. Excepting one patient all had severe haemophilia A. Nine patients were less than 50 years of age. Eight out of eleven patients had fracture after trivial trauma. Nine patients had closed reduction and one patient open reduction. The patient with non union had a Valgus osteotomy. All fractures united. The average time to union was 11 weeks (range:8–16). We followed either a low dose intermittent or a low dose continuous infusion factor support protocol for the management of these patients. The median dose of factor support was 252 u/kg (range: 136–580). The average duration of factor support was 9 days (range: 7–10). Two patients had aggravation of pre existing knee stiffness following post operative immobilisation. No other major complication was observed in this cohort of patients. To conclude, management of fracture neck of femur in patients with haemophilia is no different from general population if an adequate haemostasis is achieved.
Activating and inhibitory receptors on synovial fluid natural killer cells of arthritis patients: role of CD94/NKG2A in control of cytokine secretion
Authors: De Matos Cristina Teixeira , Berg Louise , Michaëlsson Jakob , Felländer‐Tsai Li , Kärre Klas , Söderström Kalle
Published: May 2007

Natural killer (NK) cells are activated early during inflammatory events and contribute to the shaping of the ensuing adaptive immune response. To further understand the role for NK cells in inflammation, we investigated the phenotype and function of synovial fluid (SF) NK cells from patients with chronic joint inflammation, as well as from patients with transient inflammation of the knee following trauma. We confirm that synovial NK cells are similar to the well‐characterized CD56bright peripheral blood (PB) NK‐cell subset present in healthy individuals. However, compared to this PB subset the synovial NK cells express a higher degree of activation markers including CD69 and NKp44, the latter being up‐regulated also on CD56bright NK cells in the PB of patients. Activated synovial NK cells produced interferon‐γ and tumour necrosis factor, and the production was further up‐regulated by antibody masking of CD94/NKG2A, and down‐regulated by target cells expressing human leucocyte antigen‐E in complex with peptides known to engage CD94/NKG2A. We conclude that synovial NK cells have an activated phenotype and that CD94/NKG2A is a key regulator of synovial NK‐cell cytokine synthesis.
The delivery site of a monovalent influenza vaccine within the respiratory tract impacts on the immune response
Authors: Minne Antoine , Louahed Jamila , Mehauden Sybille , Baras Benoît , Renauld Jean‐Christophe , Vanbever Rita
Published: May 2007

Pulmonary vaccination is a promising immunization route. However, there still remains a crucial need to characterize the different parameters affecting the efficacy of inhaled vaccination. This study aimed at assessing the impact of antigen distribution within the respiratory tract on the immune response to a monovalent A/Panama/2007/99 H3N2 influenza split virus vaccine administered to BALB/c mice. Varying the administration technique allowed the targeting of the vaccine to different sites of the mouse respiratory tract, i.e. the nasal cavity, the upper or central airways, or the deep lung. This targeting was verified by using ovalbumin as a tracer compound. The immune responses generated following influenza vaccine administration to the different respiratory tract sites were compared to each other and to those elicited by intramuscular and peroral intragastric immunization. Delivery of the vaccine to the different respiratory regions generated systemic, local and cellular virus‐specific immune responses, which increased with the depth of vaccine deposition, culminating in deep‐lung vaccination. The latter induced virus‐specific serum immunoglobulin G and neutralizing antibody titres as elevated as intramuscular vaccination, whereas the production of mucosal secretory immunoglobulin A was significantly superior in deep‐lung‐vaccinated animals. The analysis of cytokines secreted by mononuclear cells during an in vitro recall response indicated that deep‐lung vaccination induced a local shift of the cellular immune response towards a T helper type 1 phenotype as compared to intramuscular vaccination. In conclusion, antigen distribution within the respiratory tract has a major effect on the immune response, with the deep lung as the best target for inhaled influenza vaccination.
Epigenetic profile of testicular germ cell tumours
Authors: Okamoto Keisei , Kawakami Takahiro
Published: May 2007

DNA methylation is the best known and most thoroughly studied epigenetic mechanism. Hypermethylation of CpG islands associated with silencing of tumour suppressor genes or tumour‐related genes is a common hallmark of human cancer. The list of tumour‐related genes with aberrant hypermethylation in their CpG islands has been increasing. There is also the potential for using DNA methylation profile data as markers for various types of human cancer. In this paper, we review the methylation profile of testicular germ cell tumours (TGCTs). We show that TGCTs have distinctive DNA methylation profiles that differ from those of somatic tissue‐derived cancers or somatic tissues. We also discuss the methylation profile of TGCTs in terms of the DNA reprogramming that occurs in primordial germ cells or pre‐implantation embryos. Finally, we describe the potential clinical utility of this unique methylation phenotype in TGCTs with regard to developing a novel tumour marker. These data suggest that unmethylated DNA fragments in TGCTs may have diagnostic implications. Further elucidation of epigenetic profiles in TGCTs is expected to provide a new insight into the biology of this disease.
Development of a cross‐platform ubiquitous language learning service via mobile phone and interactive television*
Authors: Fallahkhair S. , Pemberton L. , Griffiths R.
Published: May 2007

Abstract  This paper describes the development processes for a cross‐platform ubiquitous language learning service via interactive television (iTV) and mobile phone. Adapting a learner‐centred design methodology, a number of requirements were gathered from multiple sources that were subsequently used in TAMALLE (television and mobile phone assisted language learning environment) development. A number of issues that arise in the context of cross‐platform user interface design and architecture for ubiquitous language learning were tackled. Finally, we discuss a multi‐method evaluation regime to gauge usability, perceived usefulness and desirability of TAMALLE system. The result broadly revealed an overall positive response from language learners. Although, there were some reported difficulties in reading text and on‐screen display mainly on the iTV side of the interface, TAMALLE was perceived to be a usable, useful and desirable tool to support informal language learning and also for gaining new contextual and cultural knowledge.
Affordances of mobile technologies for experiential learning: the interplay of technology and pedagogical practices
Authors: Lai C.‐H. , Yang J.‐C. , Chen F.‐C. , Ho C.‐W. , Chan T.‐W.
Published: May 2007

Abstract  Experiential learning is the process of creating knowledge through the transformation of experience and has been adopted in an increasing number of areas. This paper investigates the possibility of technological support for experiential learning. A learning activity flow (or script) and a mobile technology system were designed to facilitate students in experiential learning. An experiment was conducted on two fifth‐grade classes at an elementary school, one class using personal digital assistants (PDAs) and the other working without them. The results indicate that mobile technologies are effective in improving knowledge creation during experiential learning. The interplay between the mobile technology affordances and the proposed learning flow for experiential learning is thoroughly discussed.