bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Hypercompetence in
Legionella pneumophila
Authors: Sexton Jessica A. , Vogel Joseph P.
Published: June 2004

Although many bacteria are known to be naturally competent for DNA uptake, this ability varies dramatically between species and even within a single species, some isolates display high levels of competence while others seem to be completely nontransformable. Surprisingly, many nontransformable bacterial strains appear to encode components necessary for DNA uptake. We believe that many such strains are actually competent but that this ability has been overlooked because standard laboratory conditions are inappropriate for competence induction. For example, most strains of the gram-negative bacterium
Legionella pneumophila
are not competent under normal laboratory conditions of aerobic growth at 37°C. However, it was previously reported that microaerophilic growth at 37°C allows
L
.
pneumophila
serogroup 1 strain AA100 to be naturally transformed. Here we report that another
L
.
pneumophila
serogroup 1 strain, Lp02, can also be transformed under these conditions. Moreover, Lp02 can be induced to high levels of competence by a second set of conditions, aerobic growth at 30°C. In contrast to Lp02, AA100 is only minimally transformable at 30°C, indicating that Lp02 is hypercompetent under these conditions. To identify potential causes of hypercompetence, we isolated mutants of AA100 that exhibited enhanced DNA uptake. Characterization of these mutants revealed two genes,
proQ
and
comR
, that are involved in regulating competence in
L
.
pneumophila
. This approach, involving the isolation of hypercompetent mutants, shows great promise as a method for identifying natural transformation in bacterial species previously thought to be nontransformable.
Vibrio fischeri
LuxS and AinS: Comparative Study of Two Signal Synthases
Authors: Lupp Claudia , Ruby Edward G.
Published: June 2004

Vibrio fischeri
possesses two acyl-homoserine lactone quorum-sensing systems,
ain
and
lux
, both of which are involved in the regulation of luminescence gene expression and are required for persistent colonization of the squid host,
Euprymna scolopes
. We have previously demonstrated that the
ain
system induces luminescence at cell densities that precede
lux
system activation. Our data suggested that the
ain
system both relieves repression and initially induces the
lux
system, thereby achieving sequential induction of gene expression by these two systems. Analysis of the
V. fischeri
genome revealed the presence of a putative third system based on the enzyme LuxS, which catalyzes the synthesis of the
Vibrio harveyi
autoinducer 2 (AI-2). In this study, we investigated the impact of
V. fischeri
LuxS on luminescence and colonization competence in comparison to that of the
ain
system. Similar to the
ain
system, inactivation of the AI-2 system decreased light production in culture, but not in the squid host. However, while an
ainS
mutant produces no detectable light in culture, a
luxS
mutant expressed approximately 70% of wild-type luminescence levels. A mutation in
luxS
alone did not compromise symbiotic competence of
V. fischeri
; however, levels of colonization of an
ainS luxS
double mutant were reduced to 50% of the already diminished level of
ainS
mutant colonization, suggesting that these two systems regulate colonization gene expression synergistically through a common pathway. Introduction of a
luxO
mutation into the
luxS
and
ainS luxS
background could relieve both luminescence and colonization defects, consistent with a model in which LuxS, like AinS, regulates gene expression through LuxO. Furthermore, while
luxS
transcription appeared to be constitutive and the AI-2 signal concentration did not change dramatically, our data suggest that
ainS
transcription is autoregulated, resulting in an over 2,000-fold increase in signal concentration as culture density increased. Taken together, these data indicate that
V. fischeri
LuxS affects both luminescence regulation and colonization competence; however, its quantitative contribution is small when compared to that of the AinS signal.
Control of Photosynthetic and High-Light-Responsive Genes by the Histidine Kinase DspA: Negative and Positive Regulation and Interactions between Signal Transduction Pathways
Authors: Hsiao Hui-Yi , He Qingfang , van Waasbergen Lorraine G. , Grossman Arthur R.
Published: June 2004

We have deleted a gene for a sensor histidine kinase,
dspA
(or
hik33
), in the cyanobacterium
Synechocystis
sp. strain PCC6803. In low and moderate light, the mutant grew slowly under photoautotrophic conditions, with a doubling time of ∼40 h, and had severely reduced photosynthetic oxygen evolution. When the mutant was maintained in low or moderate light in the presence of glucose, its growth rate was only somewhat lower than that of wild-type cells. However, the mutant was light sensitive and rapidly died in high light. Furthermore, levels of many transcripts encoding genes associated with photosynthesis were altered in the mutant relative to wild-type
Synechocystis
sp. strain PCC6803 both in low light and following exposure to high light. There was constitutive expression of several high-light-inducible genes, including
hli
,
psbAIII
, and
gpx2
; there was little increased accumulation of
sodB
mRNA in high light; and the cells failed to accumulate
cpcBA
and
psaAB
mRNAs in low light in the presence of glucose, although a normal decline in the levels of these mRNAs was observed during exposure to high light. These results suggest that DspA is involved in controlling sets of photosynthetic and high-light-responsive genes, either directly or indirectly. These and other results, some of which are presented in a companion paper (C.-J. Tu, J. Shrager, R. Burnap, B. L. Postier, and A. R. Grossman, J. Bacteriol. 186:3889-3902, 2004), suggest that DspA acts as a global regulator that helps coordinate cellular metabolism with growth limitations imposed by environmental conditions.
Extensive Genomic Diversity in Pathogenic
Escherichia coli
and
Shigella
Strains Revealed by Comparative Genomic Hybridization Microarray
Authors: Fukiya Satoru , Mizoguchi Hiroshi , Tobe Toru , Mori Hideo
Published: June 2004

Escherichia coli
, including the closely related genus
Shigella
, is a highly diverse species in terms of genome structure. Comparative genomic hybridization (CGH) microarray analysis was used to compare the gene content of
E. coli
K-12 with the gene contents of pathogenic strains. Missing genes in a pathogen were detected on a microarray slide spotted with 4,071 open reading frames (ORFs) of W3110, a commonly used wild-type K-12 strain. For 22 strains subjected to the CGH microarray analyses 1,424 ORFs were found to be absent in at least one strain. The common backbone of the
E. coli
genome was estimated to contain about 2,800 ORFs. The mosaic distribution of absent regions indicated that the genomes of pathogenic strains were highly diversified becasue of insertions and deletions. Prophages, cell envelope genes, transporter genes, and regulator genes in the K-12 genome often were not present in pathogens. The gene contents of the strains tested were recognized as a matrix for a neighbor-joining analysis. The phylogenic tree obtained was consistent with the results of previous studies. However, unique relationships between enteroinvasive strains and
Shigella
, uropathogenic, and some enteropathogenic strains were suggested by the results of this study. The data demonstrated that the CGH microarray technique is useful not only for genomic comparisons but also for phylogenic analysis of
E. coli
at the strain level.
CovS Inactivates CovR and Is Required for Growth under Conditions of General Stress in
Streptococcus pyogenes
Authors: Dalton Tracy L. , Scott June R.
Published: June 2004

The gram-positive human pathogen
Streptococcus pyogenes
(group A streptococcus [GAS]) causes diseases ranging from mild and often self-limiting infections of the skin or throat to invasive and life-threatening illnesses. To cause such diverse types of disease, the GAS must be able to sense adverse environments and regulate its gene expression accordingly. The CovR/S two-component signal transduction regulatory system in GAS represses about 15% of the GAS genome, including many genes involved in virulence, in response to the environment. We report that CovR is still able to repress transcription from several promoters in the absence of the putative histidine kinase sensor for this system, CovS. We also show that a phosphorylation site mutant (D53A) of CovR is unable to repress gene expression. In addition, we report that a strain with a nonpolar mutation in CovS does not grow at a low pH, elevated temperature, or high osmolarity. The stress-related phenotypes of the CovS mutant were complemented by expression of
covS
from a plasmid. Selection for growth of a CovS mutant under stress conditions resulted in isolation of second-site mutations that inactivated
covR
, indicating that CovR and CovS act in the same pathway. Also, at 40°C in the wild-type strain, CovR appeared to be less active on the promoter tested, which is consistent with the hypothesis that it was partially inactivated by CovS. We suggest that under mild stress conditions, CovS inactivates CovR, either directly or indirectly, and that this inactivation relieves repression of many GAS genes, including the genes needed for growth of GAS under stress conditions and some genes that are necessary for virulence. Growth of many gram-positive bacteria under multiple-stress conditions requires alteration of promoter recognition produced by RNA polymerase association with the general stress response sigma factor, σ
B
. We provide evidence that for GAS, which lacks a
sigB
ortholog, growth under stress conditions requires the CovR/S two-component regulatory system instead. This two-component system in GAS thus appears to perform a function for which other gram-positive bacteria utilize an alternative sigma factor.
Genomic Diversity of
Burkholderia pseudomallei
Clinical Isolates: Subtractive Hybridization Reveals a
Burkholderia mallei
-Specific Prophage in
B. pseudomallei
1026b
Authors: DeShazer David
Published: June 2004

Burkholderia pseudomallei
is the etiologic agent of the disease melioidosis and is a category B biological threat agent. The genomic sequence of
B. pseudomallei
K96243 was recently determined, but little is known about the overall genetic diversity of this species. Suppression subtractive hybridization was employed to assess the genetic variability between two distinct clinical isolates of
B. pseudomallei
, 1026b and K96243. Numerous mobile genetic elements, including a temperate bacteriophage designated φ1026b, were identified among the 1026b-specific suppression subtractive hybridization products. Bacteriophage φ1026b was spontaneously produced by 1026b, and it had a restricted host range, infecting only
Burkholderia mallei
. It possessed a noncontractile tail, an isometric head, and a linear 54,865-bp genome. The mosaic nature of the φ1026b genome was revealed by comparison with bacteriophage φE125, a
B. mallei
-specific bacteriophage produced by
Burkholderia thailandensis
. The φ1026b genes for DNA packaging, tail morphogenesis, host lysis, integration, and DNA replication were nearly identical to the corresponding genes in φE125. On the other hand, φ1026b genes involved in head morphogenesis were similar to head morphogenesis genes encoded by
Pseudomonas putida
and
Pseudomonas aeruginosa
bacteriophages. Consistent with this observation, immunogold electron microscopy demonstrated that polyclonal antiserum against φE125 reacted with the tail of φ1026b but not with the head. The results presented here suggest that
B. pseudomallei
strains are genetically heterogeneous and that bacteriophages are major contributors to the genomic diversity of this species. The bacteriophage characterized in this study may be a useful diagnostic tool for differentiating
B. pseudomallei
and
B. mallei
, two closely related biological threat agents.
Effects of Perturbing Nucleoid Structure on Nucleoid Occlusion-Mediated Toporegulation of FtsZ Ring Assembly
Authors: Sun Qin , Margolin William
Published: June 2004

In
Escherichia coli
, assembly of the FtsZ ring (Z ring) at the cell division site is negatively regulated by the nucleoid in a phenomenon called nucleoid occlusion (NO). Previous studies have indicated that chromosome packing plays a role in NO, as
mukB
mutants grown in rich medium often exhibit FtsZ rings on top of diffuse, unsegregated nucleoids. To address the potential role of overall nucleoid structure on NO, we investigated the effects of disrupting chromosome structure on Z-ring positioning. We found that NO was mostly normal in cells with inactivated DNA gyrase or in
mukB
-null mutants lacking
topA
, although some suppression of NO was evident in the latter case. Previous reports suggesting that transcription, translation, and membrane insertion of proteins (“transertion”) influence nucleoid structure prompted us to investigate whether disruption of these activities had effects on NO. Blocking transcription caused nucleoids to become diffuse, and FtsZ relocalized to multiple bands on top of these nucleoids, biased towards midcell. This suggested that these diffuse nucleoids were defective in NO. Blocking translation with chloramphenicol caused characteristic nucleoid compaction, but FtsZ rarely assembled on top of these centrally positioned nucleoids. This suggested that NO remained active upon translation inhibition. Blocking protein secretion by thermoinduction of a
secA
(Ts) strain caused a chromosome segregation defect similar to that in
parC
mutants, and NO was active. Although indirect effects are certainly possible with these experiments, the above data suggest that optimum NO activity may require specific organization and structure of the nucleoid.
Genes Involved in Formation of Structured Multicellular Communities byBacillus subtilis
Authors: Branda Steven S. , González-Pastor José Eduardo , Dervyn Etienne , Ehrlich S. Dusko , Losick Richard , Kolter Roberto
Published: June 2004

The spore-forming bacteriumBacillus subtilisis capable of assembling multicellular communities (biofilms) that display a high degree of spatiotemporal organization. Wild strains that have not undergone domestication in the laboratory produce particularly robust biofilms with complex architectural features, such as fruiting-body-like aerial projections whose tips serve as preferential sites for sporulation. To discover genes involved in this multicellular behavior and to do so on a genome-wide basis, we took advantage of a large collection of mutants which have disruptions of most of the uncharacterized genes in theB. subtilisgenome. This collection, which was generated with a laboratory strain, was screened for mutants that were impaired in biofilm formation. This subset of mutated genes was then introduced into the wild strain NCIB 3610 to study their effects on biofilm formation in liquid and solid media. In this way we identified six genes that are involved in the development of multicellular communities. These areyhxB(encoding a putative phosphohexomutase that may mediate exopolysaccharide synthesis),sipW(encoding a signal peptidase),ecsB(encoding an ABC transporter subunit),yqeK(encoding a putative phosphatase),ylbF(encoding a regulatory protein), andymcA(a gene of unknown function). Further analysis revealed that these six genes play different roles inB. subtiliscommunity development.
Cross-Regulation in
Vibrio parahaemolyticus
: Compensatory Activation of Polar Flagellar Genes by the Lateral Flagellar Regulator LafK
Authors: Kim Yun-Kyeong , McCarter Linda L.
Published: June 2004

Gene organization and hierarchical regulation of the polar flagellar genes of
Vibrio parahaemolyticus
,
Vibrio cholerae
, and
Pseudomonas aeruginosa
appear highly similar, with one puzzling difference. Two σ
54
-dependent regulators are required to direct different classes of intermediate flagellar gene expression in
V. cholerae
and
P. aeruginosa
, whereas the
V. parahaemolyticus
homolog of one of these regulators, FlaK, appears dispensable. Here we demonstrate that there is compensatory activation of polar flagellar genes by the lateral flagellar regulator LafK.
Resuscitation of a Defective Prophage in
Salmonella
Cocultures
Authors: Figueroa-Bossi Nara , Bossi Lionello
Published: June 2004

Widely studied
Salmonella enterica
serovar Typhimurium strains ATCC 14028s and SL1344 harbor a cryptic ST64B prophage unable to produce infectious virions. We found that coculturing either strain with an isogenic sibling lacking the prophage leads to the appearance of active forms of the virus. Active phage originates from reversion of a +1 frameshift mutation at a monotonous G:C run in a presumptive tail assembly pseudogene.
MacA, a Diheme
c
-Type Cytochrome Involved in Fe(III) Reduction by
Geobacter sulfurreducens
Authors: Butler Jessica E. , Kaufmann Franz , Coppi Maddalena V. , Núñez Cinthia , Lovley Derek R.
Published: June 2004

A 36-kDa diheme
c
-type cytochrome abundant in Fe(III)-respiring
Geobacter sulfurreducens
, designated MacA, was more highly expressed during growth with Fe(III) as the electron acceptor than with fumarate. Although MacA has homology to proteins with in vitro peroxidase activity, deletion of
macA
had no impact on response to oxidative stress. However, the capacity for Fe(III) reduction was greatly diminished, indicating that MacA, which is predicted to be localized in the periplasm, is a key intermediate in electron transfer to Fe(III).
Health and Status Attainment
Authors: Elstad Jon Ivar
Published: June 2004

The issue of whether health influences mobility and status attainment has tended to be neglected in the main traditions of social mobility research. Health inequality research, however, indicates that health strongly affects transitions into and out of employment, but that the occupational mobility of the steadily employed is practically unaffected by health. This latter finding is surprising, because a plausible conjecture is that health variations influence occupational achievement also among those in continuous working careers. In this article I investigate the topic in a sample of Norwegian men born in 1946 who have been steadily employed over the course of three decades ( n= 330). Using ordinary least squares regression, I analyse whether health is associated with subsequent changes in occupational prestige, managerial position and income change. The results indicate that health variations have no impact on occupational trajectories during young adulthood. After age 40, however, significant health effects are revealed in relation to attainment of managerial position and income change, but not to changes in occupational prestige. This suggests that occupational trajectories are health-selective to some extent even among men in continuous working careers, but that these tendencies first emerge in mid-life when health has become more differentiated, and health effects are constrained by how occupational careers are typically structured in present-day societies.
Review Essay Liquid Modernity
Authors: Abrahamson Peter
Published: June 2004

In the sociology of Zygmunt Bauman, contemporary society, labelled consumer society by Bauman, is viewed as liquid modernity, which underlines mobility as indicative of our time. Globalization encapsulates the increasing mobility of capital and social elites; Bauman stresses that the present consumer society is stratified, and for the poor mobility is not an easy option. Spatial differentiation goes hand in hand with social differentiation. Increasingly, the affluent segments isolate themselves in voluntary ghettos such as gated communities, while the poor are relegated to the enforced ghetto, where they are labelled an underclass and viewed as useless and unwanted. Bauman demonstrates the development in North America as indicative of the situation elsewhere, but suggests an alternative to neo-liberal welfare state dismantling: namely the introduction of a basic income and substitution of the work ethic by an ethic of craftsmanship.
Non-Isothermal in Situ Dielectric Cure Monitoring for Thermosetting Matrix Composites
Authors: Lee Dai Gil , Kim Hyoung Geun
Published: May 2004

Cure monitoring is important for the quality and productivity of composite structures during the manufacturing process of thermosetting resin matrix composites. Since isothermal cure cycle was used in the previous researches for the dielectric cure monitoring, temperature effect could not be included effectively. In this study, dynamic cure cycle was adopted for the investigation of the composite cure process under non-isothermal conditions. Experimental results obtained from both differential scanning calorimetry (DSC) and dielectrometry under the same cure curing conditions were compared to predict the degree of cure of thermosetting resin matrix composites during the curing process. The sensitivity of dielectrometry was improved by separating the effect of sensor external on the measured signal. A new algorithm to obtain the degree of cure during non-isothermal dielectric cure monitoring for glass/polyester and glass/epoxy composites was developed by employing a function of both temperature and dissipation factor, in which five cure monitoring parameters were used to calculate the degree of cure. The decreasing pattern of dissipation factor was compared with the relationships between the degree of cure and the resin viscosity. The developed algorithm might be employed for the non-isothermal in situ cure monitoring of thermosetting resin composites.
Design of Ferromagnetic Shape Memory Alloy Composites
Authors: Kusaka Masahiro , Taya Minoru
Published: May 2004

Ferromagnetic shape memory alloy (FSMA) composites composed of a ferromagnetic material and a shape memory alloy (SMA) are key material systems for fast-responsive and compact actuators.

The function of ferromagnetic material is to induce magnetic force which is then used to induce the stress in the SMA, resulting in the stress-induced marten site transformation (SIM), i.e. change in the Young’s modulus, stiff (austenite) to soft (martensite). This SIM-induced phase change causes larger deformation in the SMA, which is often termed as “superelastic”.

This paper discusses a simple model by which the stress and strain field in the FSMA composites subjected to bending and torsion loading are computed with the aim of identifying the optimum geometry of FSMA composites. The results of the present analytical study are utilized to design torque actuator (bending of FSMA composite plate) and spring actuator (torsion of helical FSMA composite spring).
Interlaminar Stress Concentrations in Layered Structures: Part I - A Selective Literature Survey on the Free-Edge Effect since 1967
Authors: Mittelstedt Christian , Becker Wilfried
Published: May 2004

Stress concentration phenomena in composite laminates are technically important situations. A well-known problem of this class is the free-edge effect in composite laminates or as a superordinated example the stress concentrations in the vicinity of free laminate corners (so-called free-corner effect). The present work is split into two parts. In the present contribution, after a short introduction to the given stress concentration problems in general we will survey relevant selected literature on the classical free-edge effect dating from 1967 until today. Beside accentuation on approximate closed-form analytic methods for the stress analysis in the free-edge effect situation, numerous references on numerical methods and investigations on the occurring stress singularities are also cited. In a subsequent paper we will present a simple closed-form method for the analysis of the stress fields in the vicinity of free laminate corners with arbitrary layup. The method is based on adequate stress shape assumptions and a variational principle. The present article contains 136 references.
Religions et génération dans la Caraïbe
Authors: Hurbon Laënnec
Published: June 2004

Religions in the Caribbean are experienced as ways of reconstituting memory against the background of the slave trade. This is why there is an essential link between religion and generation in the region. Cults of the dead, dance and trance, and the representation of African deities reveal a permanent process of creating solidarity among the slaves (i.e of a new generation), but at the same time these cults offer the possibility of symbolizing the origins that were lost during the slave trade. With the new religious movements such as Mahikari and Rastafari, memory seems more important than history, as if the converts believe that they are contemporary with the slave trade, while considering themselves the last generation of history.
La Transmission De L’islam Auprès Des Nouvelles Générations De La Diaspora
Authors: Saint-Blancat Chantal
Published: June 2004

This is an analysis of the cultural and religious socialization of young Muslims who were born and/or brought up in Europe. Is it possible to apply to them the category of “generation”, and why? The author goes on to examine religious socialization in the family, the diversity of ways in which young people re-appropriate Islam, and their current e.orts to return to a “line of faith”. Finally, identifying changes in the processes of transmission (content and practices) throws light on the questions raised by new generations: the claim to a gender identity for women through the prism of religion, a new demand for citizenship, the problem of the search for religious authority. All these developments remove Islam from its enclave and help to distance it from being socially constructed as an exception.
The Impact of Drug Treatment and Testing Orders in West Yorkshire: Six-Month Outcomes
Authors: Turner Russell
Published: June 2004

This article provides data on the impact of drug treatment and testing orders (DTTOs) in West Yorkshire after six months. Measures of drug use, criminality, health and social situation are presented along with offender feedback. The discussion is intended to contribute towards an evidence-based debate on the future direction of policy and practice developments with regard to the improvement of the order.
An Interval Analysis Based Study for the Design and the Comparison of Three-Degrees-of-Freedom Parallel Kinematic Machines
Authors: Chablat D. , Wenger Ph. , Majou F. , Merlet J. -P.
Published: May 2004

This paper addresses an interval analysis based study that is applied to the design and the comparison of three-degrees-of-freedom (3-DoF) parallel kinematic machines. Two design criteria are used: (i) a regular workspace shape and (ii) a kinetostatic performance index that needs to be as homogeneous as possible throughout the workspace. The interval analysis based method takes these two criteria into account; on the basis of prescribed kinetostatic performances, the workspace is analyzed to find the largest regular dextrous workspace enclosed in the Cartesian workspace. An algorithm describing this method is introduced. Two 3-DoF translational parallel mechanisms designed for machining applications are compared using this method. The first machine features three fixed linear joints which are mounted orthogonally and the second features three linear joints which are mounted in parallel. In both cases, the mobile platform moves in the Cartesian x - y - z space with fixed orientation.
New Performance Indices and Workspace Analysis of Reconfigurable Hyper-Redundant Robotic Arms
Authors: Badescu Mircea , Mavroidis Constantinos
Published: May 2004

In this paper, we introduce new performance indices to characterize the workspace of reconfigurable hyper-redundant robotic arms. These indices are then used to analyze the workspace of a type of hyper-redundant robotic arm using as modules lower mobility parallel platforms. The modules of the reconfigurable robotic arm are the three-legged translational universal-prismatic-universal (UPU) and orientational universal-prismatic-spherical (UPS) parallel platforms. Each arm is composed of a large number of these modules having a very large number of degrees of freedom. Results of the workspace analysis are presented in tabular and graphical forms and the corresponding best designs are identified. All possible arm assembly configurations with two, three, and four parallel platform modules and one configuration with five parallel platform modules have been taken into consideration, analyzed, and compared.
The Sunset of Humanitarian Intervention? The Responsibility to Protect in a Unipolar Era
Authors: Weiss Thomas G.
Published: May 2004

In spite of the current preoccupations, in the United States and in the United Nations, with the wars on terrorism and the occupation in Iraq, humanitarian intervention remains an important policy option. Future debates and action are framed by the International Commission on Intervention and State Sovereignty, whose report entitled The Responsibility To Protect and an accompanying research volume were published in December 2001. Future humanitarian crises will arise in conjunction with the need for military force to protect human beings, and so four shortcomings of the report are evident. First, the report is not as forward-looking as the commissioners thought or as many opponents feared. Second, the concerns of the most vehement critics, especially developing countries, are misplaced because the problem is too little humanitarian intervention, not too much. Third, the purported danger that the concept of the responsibility to protect might become a Trojan Horse to be used by the great powers to intervene is fundamentally incorrect; rather, intervention by the USA in its pre-emptive or preventive war mode is the pressing concern. Fourth, the notion of reforming the UN Security Council is an illusion; the real challenge is to identify those humanitarian crises where Washington’s tactical multilateralism kicks in.
From Side Show to Centre Stage: Civil Conflict after the Cold War
Authors: Lacina Bethany
Published: May 2004

The end of US-Soviet rivalry has given civil war a more prominent place in international politics, as well as in scholarship. The commonly held view that the world is currently in an era of more and increasingly savage civil conflict is, in part, a matter of increased attention to a problem that has long been with us. This article reviews recent research on the incidence of internal conflict. It finds that this literature calls into question assumptions of simple causal relationships between democratization, natural resources, ethnicity, and/or inequality and civil war. The most important area of consensus is that civil war, typical of weak states, is a problem of underdevelopment as well as politics.
Learning about Touch
Authors: Dobson Susan , Carey Louisa , Conyers Ian , Upadhyaya Shripati , Raghavan Raghu
Published: May 2004

This project explores the concepts of the touch that are used in the care of people with complex needs, as held by staff in day care settings. It was undertaken to establish a baseline before the development of a local interactive training package for staff in these units. Three main themes about touch in care emerged from analysis of the data from five staff focus groups. These themes were experience of touch; the influence of service users on staff’s behaviours; and staff’s concerns about touch. Analysis of the themes also suggested that the culture of the use of touch may be different between day service units within the same locality.
Why the Difference?
Authors: Gillings-Taylor Samantha
Published: May 2004

This article is about carers being discouraged from performing regular breast examinations for women who have a learning disability and who are unable to perform it upon themselves. This follows guidelines issued by the Cancer Screening Programme in 2000. The article looks at the need to perform breast examination, draws on feminist thought and explores the possible reasons for the guidelines, focusing on issues of abuse, consent and who should perform the examination. Conclusions are reached that women who have a learning disability should receive the opportunity for breast examinations to be conducted, and recommendations are made in relation to the issues of abuse, consent and who should perform the examination.
A teenager with mixed connective tissue disease presenting with an acute coronary syndrome
Authors: Jang James J , Olin Jeffrey W , Fuster Valentin
Published: May 2004

Mixed connective tissue disease (MCTD) manifests as a number of cardiovascular diseases; however, myocardial infarction secondary to coronary artery disease has not been well documented. We present a case of a teenager with MCTD and known cardiac risk factors who developed an acute coronary syndrome.
Vascular viewpoint
Authors: Tran Huyen
Published: May 2004

Question: Is a history of pre-existing atherothrombotic disease associated with an increased risk of subsequent ischemic events, and is it associated with a reduction in efficacy of clopidogrel? Population: Patients with recent ischemic stroke (IS), myocardial infarction (MI), or established peripheral arterial disease, and a history of pre-existing symptomatic atherothrombotic disease (IS and=or MI) were enrolled in the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial. CAPRIE was a randomized, blinded, clinical trial comparing the efficacy of clopidogrel with aspirin in patients at risk of ischemic events.

Design and methods: Retrospective, subgroup analysis of 4496 patients with a prior history of symptomatic atherothrombotic disease from the CAPRIE study.

Results: Compared with the overall population of CAPRIE, patients with pre-existing symptomatic atherothrombotic disease have elevated rates of IS, MI, or vascular death. The 3-year rates of IS, MI, or vascular death were 20.4% with clopidogrel and 23.8% with aspirin (absolute risk reduction: 3.4%; 95% CI: -0.2 to 7.0; number needed to treat: 29; relative risk reduction: 14.9% (95% CI: 0.3 to 27.3; p = 0.045)). Conclusion: Patients with a history of previous symptomatic atherothrombotic disease suffer a high rate of subsequent ischemic events. Among these patients, the absolute risk reduction of clopidogrel over aspirin is greater compared with patients without pre-existing atherothrombotic disease.
The mandate for creation of a national peripheral arterial disease public awareness program: an opportunity to improve cardiovascular health
Authors: Hirsch Alan T , Gloviczki Peter , Drooz Alain , Lovell Marge , Creager Mark A ,   on behalf of The Board of Directors of the Vascular Disease Foundation
Published: May 2004

There has been increasing recognition of the detrimental impact of peripheral arterial disease (PAD) on the health of Americans, and yet there is no common national program of public PAD education designed to diminish this impact. To heighten awareness of this problem, a 2-day PAD Public Education Strategy Meeting was recently attended by representatives of 17 professional societies and public health associations whose missions support the prevention, diagnosis, treatment, and rehabilitation of vascular diseases. This Public Education Strategy Meeting was intended to provide the rationale and structure to create a national PAD public awareness campaign to diminish the health impact of PAD, and to improve cardiovascular outcomes in the USA. This paper: (1) provides the rationale for creation of a national PAD public education program; (2) reviews the development and success of national hypertension, hypercholesterolemia, and Women’s Heart Health public education programs as models of educational efficacy; (3) elucidates how the work of many vascular professionals has led to a national consensus for creation of a national PAD public educational program; (4) provides an overview of the National Heart, Lung and Blood Institute PAD education meeting; and (5) outlines the ‘next steps’ required to accomplish these goals. This meeting achieved consensus that we share responsibility for developing accurate, unified messages to promote PAD awareness and improved care. Participants agreed that the creation of such messages should be linked to plans to disseminate them to all Americans at risk. A consensus was reached that such messages, when commonly created and offered to the public, are most likely to achieve the rewards in better health that all Americans deserve. The Vascular Disease Foundation, a not-for-profit foundation whose mission includes public education regarding the prevention, diagnosis, treatment, and rehabilitation of PAD, will devote its resources to guide a new coalition in this process and to create a national PAD awareness campaign. During 2003 and 2004, the coalition will create the organizational underpinnings and timeline for what will undoubtedly be a multi-year effort. In conclusion, participants of the Public Education Strategy Meeting agreed to create a broad coalition to develop a national PAD public awareness program, with the objectives to develop and disseminate public education messages on PAD. A successful national PAD education program will contribute to the creation of a broader mandate to improve global cardiovascular health in the USA.
Isoflavones improve vascular reactivity in post-menopausal women with hypercholesterolemia
Authors: Lissin Lynette Wroblewski , Oka Roberta , Lakshmi Subbu , Cooke John P
Published: May 2004

This randomized clinical trial was designed to assess the effects of dietary isoflavones on vascular reactivity, lipid levels, and markers of inflammation in post-menopausal women. Epidemiological studies have revealed that populations consuming large amounts of soy protein have lower cardiovascular morbidity and mortality. The benefits of soy protein may be due to its hypolipidemic effects; its anti-oxidant properties; its high content of L-arginine; and=or or its phytoestrogen content. Two putative mediators of the effects of soy protein are the isoflavones genistein and daidzein. Forty post-menopausal, hypercholesterolemic women who did not take estrogen replacement therapy were recruited for this study of isoflavone supplementation. Baseline flow-mediated vasodilation and response to nitroglycerin were measured, along with urinary isoflavone and nitrite=nitrate levels and serum lipids. After 6 weeks of 90 mg of isoflavones daily versus placebo, women receiving isoflavones demonstrated improved responsiveness to nitroglycerin, an assessment of endothelium-independent vasodilation, with an effect size (percentage points change from baseline) of 7.2 1.9 versus 1.2 1.3; p = 0.01. There was a trend towards improvement of flow-mediated vasodilation, which is an endothelium-dependent response (effect size: 3.4 2.0% versus -0.6 1.7%; p = 0.12). Lipid levels were unchanged after isoflavone treatment. In conclusion, dietary isoflavones may have cardiovascular benefit in the form of improved vascular reactivity, but not by lowering cholesterol, for women who do not take estrogen replacement therapy.
Pretest Probability Estimates: A Pitfall to the Clinical Utility of Evidence‐based Medicine?
Authors: Phelps Molly A. , Levitt M. Andrew
Published: June 2004

Objectives: The Bayesian application of likelihood ratios has become incorporated into evidence‐based medicine (EBM). This approach uses clinicians' pretest estimates of disease along with the results of diagnostic tests to generate individualized posttest disease probabilities for a given patient. To date, there is minimum scientific validation for the clinical application of this approach. This study is designed to evaluate variability in the initial step of this process, clinicians' estimates of pretest probability of disease, to assess whether this approach can be expected to yield consistent posttest disease estimates. Methods:This cross‐sectional cohort study was conducted at an urban county teaching hospital by using a sample of emergency and internal medicine residents and faculty, as well as emergency department (ED) midlevel practitioners. Participants read clinical vignettes designed to raise consideration for common ED disorders and were asked to estimate the likelihood of the suggested diagnosis based on the history and physical examination findings alone. No information about laboratory results or imaging studies was provided. Results: Mean pretest probability estimates of disease ranged from 42% (95% confidence interval [95% CI] = 36.6% to 47.4%) to 77% (95% CI = 72.9% to 81.1%). The smallest difference in pretest probability magnitude for a single vignette was 70% (range 30–100%; interquartile range [IQR] 64–80%), whereas the largest was 95% (range 3–98%; IQR 30–60%). Conclusions: Wide variability in clinicians' pretest probability estimates of disease may present a possible concern about decision‐making models based on Bayes' theorem, because it may ultimately yield inconsistent posttest disease estimates.
Prevalence and Significance of Nonthromboembolic Findings on Chest Computed Tomography Angiography Performed to Rule Out Pulmonary Embolism: A Multicenter Study of 1,025 Emergency Department Patients
Authors: Richman Peter B. , Courtney D. Mark , Friese Jeremy , Matthews Jessica , Field Adam , Petri Roland , Kline Jeffrey A.
Published: June 2004

Objectives: To evaluate the hypothesis that computed tomography (CT) angiography often yields a result interpreted as an alternative diagnosis to pulmonary embolism (PE) in emergency department (ED) patients. Methods:This was a multicenter, retrospective, and secondary analysis of consecutive patients in three academic emergency departments. ED patients with symptoms suspicious for PE were included. CT angiography was ordered at the discretion of the treating physician; patients were identified by query of the electronic medical record. Board‐certified radiologists gave CT readings, which were reviewed by two independent emergency physicians who categorized the non‐PE findings into one of four acuity categories: A = requiring specific and immediate intervention, B = requiring specific action on follow‐up, C = requiring no action, and D = indeterminate findings. Results: The prevalence of PE among the 1,025 patients studied was 10% (95% CI = 8% to 12%). In the 921 patients without PE, the mean prevalences (ranges between sites) of concordant categorized non‐PE findings were: A = 7% (range 3%–11%), B = 10% (7%–13%), C = 17% (10%–20%), D = 4% (0%–8%), and no ancillary finding = 41% (29% to 45%). The most common category A findings included infiltrate or consolidation suggesting pneumonia (81%), aortic aneurysm or dissection (7%), and mass suggesting undiagnosed malignancy (7%). The overall unweighted agreement was 80% (κ= 0.72) and weighted agreement was 93% (kw = 0.84). Conclusions: In ED patients with suspected PE, the CT angiogram frequently provides evidence suggesting an important alternative diagnosis to PE. Pulmonary infiltrate suggesting pneumonia was the most common non‐PE finding.
B‐type Natriuretic Peptide for Diagnosis of Heart Failure in Emergency Department Patients: A Critical Appraisal
Authors: Schwam Eric
Published: June 2004

The diagnosis of heart failure in the outpatient setting can be difficult. A rapid assay for B‐type natriuretic peptide (BNP) has been advocated for the diagnosis of heart failure, using a single cutoff of 100 pg/mL. BNP is produced by both the right and left cardiac ventricles and is elevated in a variety of conditions, including heart failure, pulmonary hypertension, cor pulmonale, pulmonary embolism, left ventricular hypertrophy, renal failure, circulatory overload, acute coronary syndromes, atrial fibrillation, lung cancer, and sepsis. This multitude of causes of BNP elevation imposes limits on its diagnostic use for heart failure. The literature on the use of BNP testing for diagnosis of heart failure is reviewed, and improved guidelines for its interpretation are suggested.
Emergency Physician–Verified Out‐of‐hospital Intubation: Miss Rates by Paramedics
Authors: Jones James H. , Murphy Michael P. , Dickson Robert L. , Somerville Geoff G. , Brizendine Edward J.
Published: June 2004

Objectives: To prospectively quantify the number of unrecognized missed out‐of‐hospital intubations by ground paramedics using emergency physician verification as the criterion standard for verification of endotracheal tube placement. Methods:The authors performed an observational, prospective study of consecutive intubated patients arriving by ground emergency medical services to two urban teaching hospitals. Endotracheal tube placement was verified by emergency physicians and evaluated by using a combination of direct visualization, esophageal detector device (EDD), colorimetric end‐tidal carbon dioxide (ETCO2), and physical examination. Results: During the six‐month study period, 208 out‐of‐hospital intubations by ground paramedics were enrolled, which included 160 (76.9%) medical patients and 48 (23.1%) trauma patients. A total of 12 (5.8%) endotracheal tubes were incorrectly placed outside the trachea. This comprised ten (6.3%) medical patients and two (4.2%) trauma patients. Of the 12 misplaced endotracheal tubes, a verification device (ETCO2 or EDD) was used in three cases (25%) and not used in nine cases (75%). Conclusions: The rate of unrecognized, misplaced out‐of‐hospital intubations in this urban, midwestern setting was 5.8%. This is more consistent with results of prior out‐of‐hospital studies that used field verification and is discordant with the only other study to exclusively use emergency physician verification performed on arrival to the emergency department.
Evaluation of the Educational Utility of Patient Follow‐up
Authors: Sadosty Annie T. , Stead Latha G. , Boie Eric T. , Goyal Deepi G. , Weaver Amy L. , Decker Wyatt W.
Published: June 2004

Objectives: To date, no studies in emergency medicine (EM) have addressed the educational value of the Residency Review Committee for Emergency Medicine's (RRC‐EM) requirement for patient follow‐up (FU). The authors examined whether performance of patient FU improved EM resident education. Methods:All EM resident FU encounters from September 25, 2001, through September 24, 2002, were documented and analyzed. All EM residents at a regional tertiary referral emergency department (ED) initiated patient FU encounters by entering information regarding patients' initial ED presentations into a Web‐based follow‐up system (WBFUS), subsequently entered FU information, and indicated whether they thought that the specific FU encounters improved their education (yes/no). Supervising faculty members then reviewed the residents' completed FU entries. Blinded to residents' responses regarding educational utility, faculty members evaluated whether they thought the specific FU encounters were educational for the residents (yes/no). Data entered into the WBFUS were then summarized as percentages. Results: Eight hundred forty‐seven FU encounters were completed by 18 EM residents and 29 EM faculty. Ninety‐three percent of the FU entries were deemed by at least one evaluator (resident or faculty) to have educational value. Residents found the act of performing FU educational in 81.3% of cases, whereas faculty thought 80.4% were educational for the resident. Although the residents and faculty agreed on the educational value in 75.4% of cases, the overall strength of the agreement was slight to fair (kappa statistic = 0.21). Conclusions: This study indicates that EM residents and faculty believe that the act of performing patient FU has educational value for EM residents; however, the interobserver agreement between residents and faculty was low.