bluuebunny/crossref_metadata_2025 huggingface dataset:
Establishing and Maintaining Sequestration of Dam Target Sites for Phase Variation ofagn43inEscherichia coli
Authors: Kaminska Renata , van der Woude Marjan W.
Published: January 2010

Phase variation of the outer membrane protein Ag43 encoded byagn43inEscherichia coliis controlled by an epigenetic mechanism. Sequestration of the regulatory region from Dam-dependent methylation has to be established and maintained throughout a generation to obtain and maintain the OFF phase. This work shows that hemimethylated DNA, which is formed by the passage of the DNA replication fork in an ON-phase cell, can be sequestered from methylation by OxyR binding, which is thus a key event for the switch from ON to OFF. No evidence was found that the protein SeqA, which also binds to the region, is involved in sequestration. To facilitate the dissection of this process further, a novel approach was introduced that does not alter the sequence of the regulatory region or the cellular concentration of Dam or OxyR, which consists of inserting auxiliary OxyR binding sites upstream of the regulatory region. Using this strategy, it was shown that the ON-to-OFF switch frequency can be modulated without changing the OFF-to-ON frequency. The data support a model in which in an ON-phase cell, the subcellular OxyR availability at the replication fork as it passes through theagn43regulatory region is key for initiating an ON-to-OFF switch. In contrast, this availability is not a determining factor for the switch from OFF to ON. This finding shows that different variables affect these two stochastic events. This provides new insight into the events determining the stochastic nature of epigenetic phase variation.
Functional Analysis of the RdxA and RdxB Nitroreductases of
Campylobacter jejuni
Reveals that Mutations in
rdxA
Confer Metronidazole Resistance
Authors: Ribardo Deborah A. , Bingham-Ramos Lacey K. , Hendrixson David R.
Published: January 2010

Campylobacter jejuni
is a leading cause of gastroenteritis in humans and a commensal bacterium of the intestinal tracts of many wild and agriculturally significant animals. We identified and characterized a locus, which we annotated as
rdxAB
, encoding two nitroreductases. RdxA was found to be responsible for sensitivity to metronidazole (Mtz), a common therapeutic agent for another epsilonproteobacterium,
Helicobacter pylori
. Multiple, independently derived mutations in
rdxA
but not
rdxB
resulted in resistance to Mtz (Mtz
r
), suggesting that, unlike the case in
H. pylori
, Mtz
r
might not be a polygenic trait. Similarly, Mtz
r
C. jejuni
was isolated after both
in vitro
and
in vivo
growth in the absence of selection that contained frameshift, point, insertion, or deletion mutations within
rdxA
, possibly revealing genetic variability of this trait in
C. jejuni
due to spontaneous DNA replication errors occurring during normal growth of the bacterium. Similar to previous findings with
H. pylori
RdxA, biochemical analysis of
C. jejuni
RdxA showed strong oxidase activity, with reduction of Mtz occurring only under anaerobic conditions. RdxB showed similar characteristics but at levels lower than those for RdxA. Genetic analysis confirmed that
rdxA
and
rdxB
are cotranscribed and induced during
in vivo
growth in the chick intestinal tract, but an absence of these genes did not strongly impair
C. jejuni
for commensal colonization. Further studies indicate that
rdxA
is a convenient locus for complementation of mutants in
cis
. Our work contributes to the growing knowledge of determinants contributing to susceptibility to Mtz (Mtz
s
) and supports previous observations of the fundamental differences in the activities of nitroreductases from epsilonproteobacteria.
The
hdrRM
Operon of
Streptococcus mutans
Encodes a Novel Regulatory System for Coordinated Competence Development and Bacteriocin Production
Authors: Okinaga Toshinori , Niu Guoqing , Xie Zhoujie , Qi Fengxia , Merritt Justin
Published: January 2010

The
Streptococcus mutans hdrRM
operon encodes a novel two-gene regulatory system induced by high cell density. Previous studies identified
hdrM
as the only known negative regulator of competence development in
S
.
mutans
. In the present study, we demonstrated that the HdrRM system bypasses the prototypical competence gene regulators ComC and ComDE in the transcriptional regulation of the competence-specific sigma factor
comX
and the late competence genes. Similarly, the HdrRM system can abrogate the requirement for ComE to produce the bacteriocin mutacin IV. To further probe the regulatory mechanism of
hdrRM
, we created an
hdrR
overexpression strain and showed that it could reproduce each of the
hdrM
competence and mutacin phenotypes, indicating that HdrM acts as a negative regulator of HdrR activity. Using a mutacin IV-luciferase reporter, we also demonstrated that the
hdrRM
system utilizes the same promoter elements recognized by ComE and thus appears to comprise a novel regulatory pathway parallel to ComCDE.
Structural Homology between the C-Terminal Domain of the PapC Usher and Its Plug
Authors: Ford Bradley , Rêgo Ana Toste , Ragan Timothy J. , Pinkner Jerome , Dodson Karen , Driscoll Paul C. , Hultgren Scott , Waksman Gabriel
Published: January 2010

P pili are extracellular appendages responsible for the targeting of uropathogenic
Escherichia coli
to the kidney. They are assembled by the chaperone-usher (CU) pathway of pilus biogenesis involving two proteins, the periplasmic chaperone PapD and the outer membrane assembly platform, PapC. Many aspects of the structural biology of the Pap CU pathway have been elucidated, except for the C-terminal domain of the PapC usher, the structure of which is unknown. In this report, we identify a stable and folded fragment of the C-terminal region of the PapC usher and determine its structure using both X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy. These structures reveal a β-sandwich fold very similar to that of the plug domain, a domain of PapC obstructing its translocation domain. This structural similarity suggests similar functions in usher-mediated pilus biogenesis, playing out at different stages of the process. This structure paves the way for further functional analysis targeting surfaces common to both the plug and the C-terminal domain of PapC.
Role of Decreased Levels of Fis Histone-Like Protein in Crohn's Disease-Associated Adherent Invasive
E
scherichia coli
LF82 Bacteria Interacting with Intestinal Epithelial Cells
Authors: Miquel Sylvie , Claret Laurent , Bonnet Richard , Dorboz Imen , Barnich Nicolas , Darfeuille-Michaud Arlette
Published: January 2010

The interaction of Crohn's disease (CD)-associated adherent-invasive
Escherichia coli
(AIEC) strain LF82 with intestinal epithelial cells depends on surface appendages, such as type 1 pili and flagella. Histone-like proteins operate as global regulators to control the expression of these virulence factors. We evaluated the role of histone-like proteins in AIEC reference strain LF82 during infection of intestinal epithelial cells, Intestine-407, and observed that the
fis
mRNA level was decreased. The role of Fis in AIEC LF82 was determined by studying the phenotype of an LF82
fis
::Km mutant. This was the first mutant of strain LF82 that has been described thus far that is unable to express flagellin but still able to produce type 1 pili. The cyclic-di-GMP pathway linking flagella and type 1 pilus expression is not involved in Fis-mediated regulation, and we identified in the present study Fis-binding sites located upstream of the
fimE
gene and in the intergenic region between
fimB
and
nanC
of the
fim
operon encoding type 1 pili. The major consequence of decreased Fis expression in AIEC bacteria in contact with host cells is a direct downregulation of
fimE
expression, leading to the preferential ON phase of the
fimS
element. Thus, by maintaining type 1 pilus expression, AIEC bacteria, which interact with the gut mucosa, have greater ability to colonize and to induce inflammation in CD patients.
The Physiological Stimulus for the BarA Sensor Kinase
Authors: Gonzalez Chavez Ricardo , Alvarez Adrian F. , Romeo Tony , Georgellis Dimitris
Published: January 2010

The two-component signal transduction system (TCS) BarA/UvrY activates transcription of CsrB and CsrC noncoding RNAs, which act by sequestering the RNA-binding global regulatory protein CsrA. Here, we show that the metabolic end products formate and acetate provide a physiological stimulus for this TCS and thus link posttranscriptional regulation by the Csr system to the metabolic state of the cell.
Identification of excitation and reaction forces spectra for offshore platforms
Authors: Elshafey A. A. , Haddara M. R. , Marzouk H.
Published: February 2010

A simple method is used to predict damping and natural frequencies of a fixed offshore platform subjected to wind-generated random waves using its stationary response. The method also predicts the reaction forces and bending moment at the foundation of the platform. The method uses the random decrement signature as a tool to identify the parameters in the equation of motion. Excellent agreements were obtained between the estimated and actual values of the parameters as well as for the reaction and moment at the platform foundation. The method can be applied without any interruption to the operation of the offshore structure. The method is easy to apply and uses inexpensive motion measurement instruments. The estimated forces and bending moments can be used as a tool for an on-line foundation check. A study on the limitations of applying the random decrement technique is also presented.
Early strength gain of mortar with prehydration of the cements
Authors: Topçu İlker Bekir , Şengel Hasan Selim
Published: February 2010

In this study, early hardening and strength gain of mortar samples with prehydration have been studied and effects of prehydrated cement amount and duration on the compressive strength of the mortar have been examined. The compressive strengths and ultrasound pulse velocities, resonance frequencies, bending strengths, and setting times of prepared samples have been determined by conducting tests on 4 cm × 4 cm × 16 cm samples prepared for this purpose at 2, 7, and 28 d. When the setting times are evaluated, the heat released as a result of hydration declines, and the initial heat is reduced. A significant increase in the early compressive strength as an effect of prehydration method has been observed. It is evaluated that prehydration is an economical and practical method that can be enhanced and used in the production of the ready-mix concrete and prefabricated construction materials.
Molecular epidemiology of Staphylococcus aureus in food samples based on the protein A gene polymorphic region DNA sequence
Authors: Soltan-Dallal M. M. , Salehipour Z. , Mehrabadi Jalil F.
Published: February 2010

Foodborne disease due to Staphylococcus aureus is a common and important disease worldwide. Molecular typing of S. aureus strains plays a crucial role in epidemiological studies examining the origin and performing surveillance of major infections. In this survey, we collected 913 food samples and detected 93 S. aureus isolates by using culture and biochemical tests. Subsequently, the X region of the protein A gene was amplified by the polymerase chain reaction (PCR) and amplicons were digested with HaeII and HindIII. Seven different patterns, ranging in length between 1200 and 1600 bp, showed gene polymorphism of the spa gene. The most prevalent spa types were D (20%) and C (16%) in dairy products and D (6%) and E (3%) in meat products. Consequently, 16 genotypes were obtained by HaeII digestion. Typeability of PCR – restriction fragment length polymorphism in genotyping of S. aureus strains in our study was perfect. Therefore, this method is a reliable, rapid, and powerful system in epidemiological investigations.
Reduced mechanical efficiency of rat papillary muscle related to degree of hypertrophy of cardiomyocytes
Authors: Wong Yeun Ying , Handoko M. Louis , Mouchaers Koen T. B. , de Man Frances S. , Vonk-Noordegraaf Anton , van der Laarse Willem J.
Published: January 2010

Isolated rat papillary muscles of the right ventricle were used to discover the origin of reduced myocardial efficiency in chronic heart failure. Right ventricular hypertrophy was induced by monocrotaline injection, causing pulmonary hypertension. Control ( n = 7) and hypertrophied ( n = 11) papillary muscles were subjected to sinusoidal length changes at 37°C and 5 Hz with a peak-to-peak amplitude of 15% of the length giving maximum force ( Lmax) after being stretched to 92.5% of Lmax. Isometric tension at Lmaxwas similar in control and hypertrophied muscles. Work was assessed from the area encompassed by force-length loops. Work per loop was 0.93 ± 0.11 and 0.84 ± 0.11 μJ/mm3(means ± SE) for control and hypertrophied muscles, respectively ( P = 0.591). Suprabasal O2uptake per work loop was 5.7 ± 0.7 pmol/mm3in control muscles and 8.7 ± 1.7 pmol/mm3in hypertrophied muscles ( P = 0.133). Net mechanical efficiency was calculated from the ratio of work output and suprabasal O2uptake. The efficiency of hypertrophied muscles was 29.1 ± 3.7% and was smaller than in control muscles (43.7 ± 2.2%, P = 0.016). The right ventricular cardiomyocyte cross-sectional area increased from 272 ± 17 μm2in control muscles to 396 ± 31 μm2in hypertrophied muscles ( P < 0.003). Mechanical efficiency correlated negatively with right ventricular wall thickness and cardiomyocyte cross-sectional area [Spearman rank correlation coefficients of −0.50 ( P = 0.039) and −0.53 ( P = 0.024), respectively]. We conclude that efficiency decreases with increasing cardiomyocyte hypertrophy. Thus, the reduced efficiency of diseased whole hearts can be at least partly explained by reduced efficiency at the cardiomyocyte level.
Cardiovascular effects of inhibition of renin-angiotensin-aldosterone system components in hypertensive rats given salt excess
Authors: Susic Dinko , Varagic Jasmina , Frohlich Edward D.
Published: January 2010

This study examined the role of the renin-angiotensin-aldosterone system (RAAS) in mediating cardiovascular and renal damage in spontaneously hypertensive rats (SHR) given salt excess. Since the circulating RAAS is inhibited in this model, it permits examination of the role of local tissue RAASs in mediating this injury. To this end, male 8-wk SHR were divided into 7 groups. The control group (C) received normal NaCl (0.6%) diet. All other groups were given 8% NaCl chow. In addition, group 2 was given placebo, group 3 the mineralocorticoid receptor blocker eplerenone (100 mg·kg−1·day−1), group 4 the angiotensin converting enzyme inhibitor quinapril (3 mg·kg−1·day−1), group 5 the angiotensin II type 1 receptor blocker candesartan (10 mg·kg−1·day−1), and groups 6 and 7 eplerenone and either quinapril or candesartan. The treatments lasted 8 wk. Compared with controls, mean arterial pressure (MAP), renal blood flow, coronary flow reserve, minimal coronary vascular resistance, diastolic time constant, and maximal rate of ventricular pressure fall were all adversely affected by salt loading. Left ventricular mass and fibrosis as well as proteinuria were also markedly increased by salt overload. Eplerenone induced only slight changes, whereas quinapril and candesartan normalized all indexes except MAP. Combination therapy also normalized all indexes, including MAP. These data suggest that 1) cardiovascular and renal damage induced by salt excess in the SHR were not pressure dependent; 2) mineralocorticoids were only marginally involved in this model; and 3) local tissue generation of angiotensin II may be, at least in part, responsible for the other adverse effects.
Metabolic syndrome reduces the contribution of K+ channels to ischemic coronary vasodilation
Authors: Borbouse Léna , Dick Gregory M. , Payne Gregory A. , Berwick Zachary C. , Neeb Zachary P. , Alloosh Mouhamad , Bratz Ian N. , Sturek Michael , Tune Johnathan D.
Published: January 2010

This investigation tested the hypothesis that metabolic syndrome decreases the relative contribution of specific K+ channels to coronary reactive hyperemia. Ca2+-activated (BKCa), voltage-activated (KV), and ATP-dependent (KATP) K+ channels were investigated. Studies were conducted in anesthetized miniature Ossabaw swine fed a normal maintenance diet (11% kcal from fat) or an excess calorie atherogenic diet (43% kcal from fat, 2% cholesterol, 20% kcal from fructose) for 20 wk. The latter diet induces metabolic syndrome, increasing body weight, fasting glucose, total cholesterol, and triglyceride levels. Ischemic vasodilation was determined by the coronary flow response to a 15-s occlusion before and after cumulative administration of antagonists for BKCa (penitrem A; 10 μg/kg iv), KV (4-aminopyridine; 0.3 mg/kg iv) and KATP (glibenclamide; 1 mg/kg iv) channels. Coronary reactive hyperemia was diminished by metabolic syndrome as the repayment of flow debt was reduced ∼30% compared with lean swine. Inhibition of BKCa channels had no effect on reactive hyperemia in either lean or metabolic syndrome swine. Subsequent inhibition of KV channels significantly reduced the repayment of flow debt (∼25%) in both lean and metabolic syndrome swine. Additional blockade of KATP channels further diminished (∼45%) the repayment of flow debt in lean but not metabolic syndrome swine. These data indicate that the metabolic syndrome impairs coronary vasodilation in response to cardiac ischemia via reductions in the contribution of K+ channels to reactive hyperemia.
Calcium-independent phospholipase A2plays a key role in the endothelium-dependent contractions to acetylcholine in the aorta of the spontaneously hypertensive rat
Authors: Wong Michael S. K. , Man Ricky Y. K. , Vanhoutte Paul M.
Published: January 2010

Phospholipase A2(PLA2), a regulatory enzyme found in most mammalian cells, catalyzes the breakdown of membrane phospholipids to arachidonic acid. There are two major cytosolic types of the enzyme, calcium-dependent (cPLA2) and calcium-independent (iPLA2) PLA2. The present study investigated whether or not iPLA2plays a role in the endothelium-dependent contractions of the aorta of the spontaneously hypertensive rat and its normotensive counterpart, the Wistar-Kyoto rat. The presence of iPLA2in the endothelial cells was identified by using immunochemistry and immunoblotting. Aortic rings with and without the endothelium were suspended in organ chambers for isometric tension recording. The production of prostanoids was measured by using enzyme immunoassay kits. iPLA2was densely distributed in endothelial cells of the aorta of both strains. At 3 × 10−6M, the selective iPLA2inhibitor, bromoenol lactone (BEL), abrogated endothelium-dependent contractions induced by acetylcholine but not those evoked by the calcium ionophore A-23187. The effects of BEL were similar in the aortae of Wistar-Kyoto and spontaneously hypertensive rats. The nonselective PLA2inhibitor quinacrine abolished the contractions triggered by both acetylcholine and A-23187, whereas the store-operated calcium channel inhibitor SKF-96365 prevented only the acetylcholine-induced contraction. The acetylcholine- but not the A-23187-induced release of 6-keto prostaglandin F1αwas inhibited by BEL. The release of thromboxane B2by either acetylcholine or A-23187 was not affected by BEL. In conclusion, iPLA2plays a substantial role in the generation of endothelium-derived contracting factor evoked by acetylcholine.
Cardiotonic pills, a compound Chinese medicine, protects ischemia-reperfusion-induced microcirculatory disturbance and myocardial damage in rats
Authors: Zhao Na , Liu Yu-Ying , Wang Fang , Hu Bai-He , Sun Kai , Chang Xin , Pan Chun-Shui , Fan Jing-Yu , Wei Xiao-Hong , Li Xiang , Wang Chuan-She , Guo Zhi-Xin , Han Jing-Yan
Published: January 2010

Cardiotonic pills (CP) is a compound Chinese medicine widely used in China, as well as other countries, for the treatment of cardiovascular disease. However, limited data are available regarding the mechanism of action of CP on myocardial function during ischemia-reperfusion (I/R) injury. In this study, we examined the effect of CP on I/R-induced coronary microcirculatory disturbance and myocardial damage. Male Sprague-Dawley rats were subjected to left coronary anterior descending branch occlusion for 30 min followed by reperfusion with or without pretreatment with CP (0.1, 0.4, or 0.8 g/kg). Coronary blood flow, vascular diameter, velocity of red blood cells, and albumin leakage were evaluated in vivo after reperfusion. Neutrophil expression of CD18, malondialdehyde, inhibitor-κBα, myocardial infarction, endothelial expression of intercellular adhesion molecule 1, apoptosis-related proteins, and histological and ultrastructural evidence of myocardial damage were assessed after reperfusion. Pretreatment with CP (0.8 g/kg) significantly attenuated the I/R-induced myocardial microcirculatory disturbance, including decreased coronary blood flow and red blood cell velocity in arterioles, increased expression of CD18 on neutrophils and intercellular adhesion molecule 1 on endothelial cells, and albumin leakage from venules. In addition, the drug significantly ameliorated the I/R-induced myocardial damage and apoptosis indicated by increased malondialdehyde, infarct size, myocardial ultrastructural changes, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive myocardial cells, inhibitor-κBα degradation, and expression of Bcl-2, Bax, and caspase-3 in myocardial tissues. The results provide evidence for the potential role of CP in preventing microcirculatory disturbance and myocardial damage following I/R injury.
Simulations under Ideal and Nonideal Conditions for Characterization of a Passive Doppler Geographical Location System Using Extension of Data Reception Network
Authors: de Sousa Cristina Tobler , de Moraes Rodolpho Vilhena , Kuga Hélio Koiti
Published: January 2010

This work presents a (Data Reception Network) DRN software investigation considering simulated conditions inserting purposely errors into the Doppler measurements, satellites ephemeris, and time stamp, to characterize the geographical location software (GEOLOC) developed by Sousa (2000) and Sousa et al. (2003). The extension of reception stations in Brazilian territory can result in more precise locations if the network is considered in the GEOLOC. The results and analyses were first obtained considering the ground stations separately, to characterize their effects in the geographical location (GL) result. Six conditions were investigated: ideal simulated conditions, random and bias errors in the Doppler measurements, errors in the satellite ephemeris, and errors in the time stamp in order to investigate the DRN importance to get more accurate locations; an analysis was performed considering the random errors of 1 Hz in the Doppler measurements. The results are quite satisfactory and also show good compatibility between the simulator and the GEOLOC using the DRN.
Synonymous Codon Usage Analysis of Thirty Two Mycobacteriophage Genomes
Authors: Hassan Sameer , Mahalingam Vasantha , Kumar Vanaja
Published: February 2010

Synonymous codon usage of protein coding genes of thirty two completely sequenced mycobacteriophage genomes was studied using multivariate statistical analysis. One of the major factors influencing codon usage is identified to be compositional bias. Codons ending with either C or G are preferred in highly expressed genes among which C ending codons are highly preferred over G ending codons. A strong negative correlation between effective number of codons (Nc) and GC3s content was also observed, showing that the codon usage was effected by gene nucleotide composition. Translational selection is also identified to play a role in shaping the codon usage operative at the level of translational accuracy. High level of heterogeneity is seen among and between the genomes. Length of genes is also identified to influence the codon usage in 11 out of 32 phage genomes. Mycobacteriophage Cooper is identified to be the highly biased genome with better translation efficiency comparing well with the host specific tRNA genes.
A Note on Four‐Variable Reciprocity Theorem
Authors: Adiga Chandrashekar , Guruprasad P. S.
Published: February 2010

We give new proof of a four‐variable reciprocity theorem using Heine′s transformation, Watson′s transformation, and Ramanujan′s 1 ψ 1‐summation formula. We also obtain a generalization of Jacobi′s triple product identity.
Transient MHD Double‐Diffusive Natural Convection over a Vertical Surface Embedded in a Non‐Darcy Porous Medium
Authors: Al-Odat Mohammed Q. , Al-Azab Tariq A. , Al-Hasan M. , Shannak B. A.
Published: February 2010

The problem of transient, laminar, MHD double‐diffusive free convection over a permeable vertical plate embedded in Darcy and non‐Darcy porous medium is numerically investigated. Nonsimilarity solutions are obtained for constant wall temperature and concentration with a specified power law of mass flux parameter. The effects of the magnetic parameter, the inertial coefficient, Lewis number, the buoyancy ratio, and the lateral mass flux on heat and mass transfer coefficients are presented and discussed.
Collaborator: A Nonholonomic Multiagent Team for Tasks in a Dynamic Environment
Authors: Ren Jing , Green Mark
Published: February 2010

In our previous work, we proposed a potential field-based hybrid path planning scheme for robot navigation that achieves complete coverage in various tasks. This paper is an extension of this work producing a multiagent framework, Collaborator, that integrates a high-level negotiation-based task allocation protocol with a low-level path planning method taking into consideration several real-world robot limitations such as nonholonomic constraints. Specifically, the proposed framework focuses on a class of complex motion planning problems in which robots need to cover the whole workspace, coordinate the accomplishment of a task, and dynamically change their roles to best fit the task. Applications in this class of problems include bomb detection and removal as well as rescuing of survivors from accidents or disasters. We have tested the framework in simulations of several tasks and have shown that Collaborator can satisfy nonholonomic constraints, cooperatively accomplish given tasks in an initially unknown dynamic environment while avoiding collision with other team members. Finally we prove that the proposed control laws are stable using the Lyapunov stability theory.
CATHARE Multi-1D Modeling of Coolant Mixing in VVER-1000 for RIA Analysis
Authors: Spasov I. , Donov J. , Kolev N. P. , Sabotinov L.
Published: January 2010

The paper presents validation results for multichannel vessel thermal-hydraulic models in CATHARE used in coupled 3D neutronic/thermal hydraulic calculations. The mixing is modeled with cross flows governed by local pressure drops. The test cases are from the OECD VVER-1000 coolant transient benchmark (V1000CT) and include asymmetric vessel flow transients and main steam line break (MSLB) transients. Plant data from flow mixing experiments are available for comparison. Sufficient mesh refinement with up to 24 sectors in the vessel is considered for acceptable resolution. The results demonstrate the applicability of such validated thermal-hydraulic models to MSLB scenarios involving thermal mixing, azimuthal flow rotation, and primary pump trip. An acceptable trade-off between accuracy and computational efficiency can be obtained.
Computer Implementation of a Coupled Boundary and Finite Element Methods for the Steady Exterior Oseen Problem
Authors: Feng Minfu , He Yinnian , Ren Ruiting
Published: February 2010

We present a numerical technique based on the coupling of boundary and finite element methods for the steady Oseen equations in an unbounded plane domain. The present paper deals with the implementation of the coupled program in the two‐dimensional case. Computational results are given for a particular problem which can be seen as a good test case for the accuracy of the method.
A Novel Use of 3D Motion Capture: Creating Conceptual Links between Technology and Representation of Human Gesture in the Visual Arts
Authors: Shan Gongbing , Visentin Peter , Harnett Tanya
Published: February 2010

As an unfolding of time-based events, gesture is intrinsically integrated with the aesthetic experience and function of the human form. In historical and contemporary visual culture, various approaches have been used to communicate the substance of human movement, including use of science and technology. This paper links the understanding of human gesture with technologies influencing its representation. Three-dimensional motion capture permits the accurate recording of movement in 3D computer space and provides a new means of analyzing movement qualities and characteristics. Movement signatures can be related to the human form by virtue of trajectory qualities and experientially and/or culturally dependent interactions.
Computational Aesthetics as a Negotiated Boundary
Authors: Blackwell Alan F. , Dodgson Neil A.
Published: February 2010

Artists use computers in many ways; technologists produce computerised tools of various kinds. The boundary where art meets technology is in creative tension between the needs and the understanding of the two camps. We report on the key questions raised at a meeting between philosophers, psychologists, artists, and technologists to negotiate this boundary.
We Don't Do Google, We Do Massive Attacks: Notes on Creative R&D Collaborations
Authors: Foster Jonathan , Lin Angela , Edmonds Ernest
Published: February 2010

The article presents findings from an exploratory study investigating the nature of collaborative research and development in creative industries. Participants in the study are two creative SMEs with extensive experience of participating in collaborative projects. A collective case study approach is adopted with data collected on the factors impinging on the effectiveness of such collaborations. Findings are presented at the macro and micro levels of such collaborations. The paper concludes with a summary of some of the challenges faced by small creative SMEs when collaborating with other organizations during the research and development process.
Creative Assemblages: Organisation and Outputs of Practice-Led Research
Authors: Wilkie Alex , Gaver William , Hemment Drew , Giannachi Gabriella
Published: February 2010

In this note we explore the organisation of creative, practice-led projects and the variety of research outcomes they produce, in order to question assumptions about their potential benefits.
Simplified Pediatric Electrocardiogram Interpretation
Authors: Evans William N. , Acherman Ruben J. , Mayman Gary A. , Rollins Robert C. , Kip Katrinka T.
Published: January 2010

We describe a simplified method for interpreting a pediatric electrocardiogram (EKG). The method uses 4 steps and requires only a few memorized rules, and it can aid health care providers who do not have immediate access to pediatric cardiology services. Most pediatric EKGs are normal. However, both abnormal and normal EKGs should be sent to a pediatric cardiologist for later, confirmatory interpretation.
A Survey of Physician-Led Influenza Immunization Programs in Schools
Authors: Hull Harry F.
Published: January 2010

To determine whether school-located immunization programs (SIPs) offer an efficient method of immunizing children aged 5 to 18 years now recommended for annual influenza immunization, the author interviewed 8 of 10 physicians (identified through media reports and personal communication) who independently conducted SIPs during 2005-2007. SIPs targeted 1 to 6 schools (mainly smaller private schools) and immunized ≤33% of eligible students. Permission and payment were obtained in advance. All SIPs offered live attenuated influenza vaccines. The physicians organized the SIPs and secured the commitment of school nurses and administrators. With 1 exception, physicians were able to recoup all costs associated with the SIP. All physicians found their experience personally rewarding and expressed a willingness to organize future SIPs. Physician-led SIPs are a viable means for immunizing schoolchildren against influenza and, if properly planned, can become self-sustaining annual events, particularly in private schools.
Multiple Psychiatric Diagnoses Common in Privately Insured Children on Atypical Antipsychotics
Authors: Halloran Donna R. , Swindle Jason , Takemoto Steve K. , Schnitzler Mark A.
Published: January 2010

Objective. To evaluate the prevalence of atypical antipsychotic use in privately insured children and the diagnoses associated with treatment. Study design. Claims were used to conduct a retrospective cohort study of children aged 2 through 18 years in the Midwest, covered by private insurance between 2002 and 2005 (n = 172 766). The 1-year prevalence of children receiving atypical antipsychotics was determined along with associated diagnoses. Results. The 1-year prevalence of atypical antipsychotics ranged from 7.9 per 1000 in 2002 to 9.0 in 2005. The leading diagnoses were disruptive behavior disorders (67%), mood disorders (65%), and anxiety disorders (43%).The authors found that 75% of children on atypical antipsychotics had more than one psychiatric diagnosis. Conclusions. Atypical antipsychotic use is primarily seen in children who have multiple psychiatric diagnoses. Studies are needed to assess the long-term safety and effectiveness in such patients with multiple diagnoses.
One Community’s Perspective on the Withdrawal of Cough and Cold Medications for Infants and Young Children
Authors: Yaghmai Beryl F. , Cordts Casey , Ahlers-Schmidt Carolyn R. , Issa Brenda A. , Warren Ramona C.
Published: January 2010

The study goals were to assess, via survey ( a) parental knowledge regarding the use of over-the counter (OTC) cough and cold medicines in children younger than the age of 6 years and ( b) the effects of the Food and Drug Administration (FDA) recommendations on community pediatricians following voluntary withdrawal of these medications. Of the 179 parents surveyed, approximately 60% had used OTC cough and cold medicines in the past, and many parents indicated an inappropriate dose when asked. Parents who were aware of the recall were significantly less likely to continue use ( P < .05). All 33 physicians surveyed were aware of the withdrawal of these medications for children younger than age 2 years and most were aware of consideration to remove these medications for children <6 years old. A total of 15% of physicians reported that FDA considerations were likely to change their practice by reducing or discontinuing use of these medications, whereas 6% would continue recommending these medications.
A Breath Biofeedback Computer Game for Children With Cystic Fibrosis
Authors: Bingham Peter M. , Bates Jason H. T. , Thompson-Figueroa John , Lahiri Thomas
Published: January 2010

The authors sought to develop and test a breath-controlled video game using a digital spirometer that, by providing visual breath biofeedback, could promote awareness of breathing techniques in children with cystic fibrosis (CF). To assess improvement in game performance during hospitalizations for CF exacerbations, the authors conducted a trial on 10 inpatients. Subjects had at least five 15-minute exposures to a breath biofeedback game that challenged them to track a moving target using their breath. Subjects reacted positively to the breath tracking challenge. Repeated-measures analysis of variance of a tracking fidelity statistic showed improvement in eye—breath coordination over 5 sessions ( P = .026). It was concluded that an electronic breath game is safe and can improve breath awareness among children with CF. This technology could also contribute to awareness of respiratory symptoms and foster social ties among CF patients.
Neonatal Lupus Erythematosus: Three Case Reports and Review of the Chinese Literature
Authors: Wei Sun  , Yuan Tian-Ming , Chen Li-Hua , Yu Hui-Min
Published: January 2010

To recognize the clinical characteristics and outcomes of neonatal lupus erythematosus (NLE), the authors retrospectively review 3 NLE babies in their department and compared their data with 51 NLE cases reported in the available Chinese literature between January 1991 and December 2008. Most of the cases were located near the eastern coast of China, and clinical manifestation of 72.22% of the cases occurred in 2-week-old babies. Skin findings occurred in 94.44% of the patients, 12.96% with complete heart block (CHB), 22.22% with thrombocytopenia, and 14.81% with transient elevated transaminase levels. Cutaneous lesions, thrombocytopenia, and transaminase level showed improvement; 3 CHB cases had persisted after 7 to 10 years follow-up, and 1 case died in 5 months. Twenty-four (44.44%) pregnant woman with anti-Ro/SSA and/or anti-La/SSB antibodies are asymptomatic, and antibody status is first indicated when their child shows symptoms of NLE. Thus, all pregnant women should be screened for anti-Ro/ SSA and anti-La/SSB antibodies.
Staphylococcus aureus Skin and Soft Tissue Infections: Can We Anticipate the Culture Result?
Authors: Bar-Meir Maskit , Tan Tina Q.
Published: January 2010

This prospective study was designed to evaluate predictors of skin and soft tissue infections (SSTI) due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Consecutive patients who were hospitalized with S aureus SSTI were enrolled. CA-MRSA infection was diagnosed in 76% of the children. MRSA SSTI was associated with black race ( P = .0001) and with infection involving the lower trunk ( P = .008). Only 21% of the patients in this study had S aureus colonization in their nares, and in 3 cases there was discordance between the nares and the infection site cultures. Sensitivity, specificity, and predictive values of the risk factors examined were limited in their ability to predict CA-MRSA infection. Given the high prevalence of MRSA in our community and the inability of nasal cultures to reliably predict CA-MRSA infection, empirical antibiotic therapy active against CA-MRSA and contact isolation of patients are recommended.
Diagnosis and Management of Bleeding Disorder in a Child
Authors: Sarnaik Amit , Kamat Deepak , Kannikeswaran Nirupama
Published: January 2010

Children with symptoms of bleeding and bruising are commonly seen in clinical practice. Primary care providers should be able to decide when and whether evaluation for bleeding disorder is warranted. This decision depends on one’s index of suspicion for bleeding disorder based on history, physical examination, and screening laboratory investigations. Knowledge of the hemostatic physiology is essential to be able to order appropriate laboratory investigations and their accurate interpretation. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and blood platelet concentration constitute the initial diagnostic work up of any bleeding disorder. Abnormality in any of these parameters in a child with excessive bleeding should lead to presumptive diagnosis of bleeding disorder and trigger referral to a hematologist for confirmation and definitive treatment. Awareness of basic treatment principles for management of bleeding/clotting disorders may prepare the provider to develop appropriate management plans, especially in a life threatening situation.
How Can We Communicate About Vaccines With Adolescents and Their Parents?
Authors: Benin Andrea L. , Wu Ann C. , Holmboe Eric S. , Shapiro Eugene D. , Anyan Walter
Published: January 2010

Objective: To describe parents’ and adolescents’ perceptions about vaccination. Methods: Qualitative interviews of 22 mothers/grandmothers and 25 10- to 14-year-olds. Results: Themes emerged in 3 focus areas. ( a) Understanding: Both adults and adolescents had difficulty understanding concepts of risks, benefits, prevention, and vaccination. ( b) Decision making: Adults saw vaccination as an opportunity to help their adolescent develop skills for transition to adulthood. Adolescents worried about being lied to (reinforced by being told “it won’t hurt”), physical pain, and cleanliness. ( c) Preventing sexually transmitted infections: Adults were divided between those who felt their child would not need such a vaccine and those who wanted to “be safe” to protect their child in the future. Conclusions: At the same time that even basic concepts about vaccination should be explained to both adults and adolescents, adolescence represents a time for learning about responsible decision making. Discussion regarding the risks and benefits of vaccines can be part of transitioning to adult decision making.
Sources of Parenting Information in Low SES Mothers
Authors: Berkule-Silberman Samantha B. , Dreyer Benard P. , Huberman Harris S. , Klass Perri E. , Mendelsohn Alan L.
Published: January 2010

This study examined 3 questions: (1) What are sources from which low socioeconomic status (SES) mothers of newborns receive parenting information? (2) To what extent are sociodemographic characteristics associated with sources? (3) To what extent are sources associated with intentions regarding activities with infants? In this cross-sectional analysis, mothers were interviewed during the postpartum period about potential sources of information about parenting and asked if and when they planned to initiate shared reading and television exposure during infancy. Maternal high school graduation, US birth, non-Latina ethnicity, language English, higher SES, and firstborn child were each associated with one or more categories representing important sources of parenting information. In adjusted analyses, print, physicians and other health care professionals, and family/friends as important sources of information were each significantly associated with increased frequency of intention to begin shared reading in infancy; television as an important source was associated with intention to begin television in infancy.
Severe Hypothyroidism Presenting as Obstructive Sleep Apnea
Authors: Rosen Dennis
Published: January 2010

A 5-year-old child with Down syndrome (DS) diagnosed with mild to moderate obstructive sleep apnea (OSA) and subsequently found to have severe hypothyroidism is presented. Following 3 months of treatment with levothyroxine, she had full resolution of her OSA. This case underscores the importance of routine thyroid function screening in children with DS and demonstrates that OSA in children with DS can be caused by other underlying medical issues that themselves require therapy, such as the hypothyroidism in this child. Although empiric testing of thyroid function is not recommended as part of the routine workup of patients with OSA, when caring for children at higher risk for thyroid dysfunction, such as those with DS, it is important to establish whether or not it is present, as treating it may bring about partial or full resolution of the OSA, as was shown to occur in this patient.
Parental Satisfaction and the Ability to Recall the Physician’s Name
Authors: Patel Minal R. , Cabana Michael D.
Published: January 2010

During urgent care visits, families may not see their regular physician and may not even recall the name of their provider. The authors conducted a cross-sectional parental satisfaction survey at pediatric ambulatory clinics to assess whether parent recall of their treating physician’s name is associated with parental satisfaction. For urgent care, ability to recall the physician’s name was positively associated with parental satisfaction (odds ratio [OR] = 2.14; 95% confidence interval [CI] = 1.76-2.60). Factors associated with dissatisfaction were parking difficulty (OR = 0.38; 95% CI = 0.26-0.57) and increasing visit time (OR = 0.87; 95% CI = 0.81-0.94). In urgent care clinics, not being able to recall the treating physician’s name is associated with dissatisfaction. Although there are many factors associated with satisfaction that are not in the physician’s control, there may be simple actions associated with improved satisfaction that physicians can implement, such as clearly introducing themselves and making sure parents remember their name.
Are Serial Brain Imaging Scans Required for Children Who Have Suffered Acute Intracranial Injury Secondary to Blunt Head Trauma?
Authors: Schnellinger Mark G. , Reid Samuel , Louie Jeffrey
Published: January 2010

In most instances, infants and children with moderate to severe head trauma undergo a head computed tomography (CT) scan as part of their initial evaluation. Several authors have advocated a routine second head CT after traumatic brain injury (TBI) to identify progressive lesions that may require surgical intervention. However, recent studies have challenged the need for a routine second brain imaging study after TBI. In addition, recent reports have raised concerns about the potential for malignancy following CT scanning, especially in pediatric patients. The authors performed a retrospective case series of all patients, aged 0 to 21 years, who presented to their 2 emergency departments (EDs) and received an International Classification of Disease—9th revision code related to intracranial injury. Out of 47 children, 5 (11%) underwent neurosurgical intervention following their second imaging study, and 1 of these interventions was unplanned after the first study. Compared with children who did not require an intervention following their second scan, children who received an intervention were more likely to have been subjected to nonaccidental trauma and to have presented to the ED more than 4 hours after the injury. Most children with intracranial injury following blunt trauma who did not require immediate neurosurgical intervention but instead underwent a follow-up brain imaging study did not require subsequent unplanned neurosurgical intervention. Serial brain imaging may not be required for all children with intracranial injury.
Pediatric Board Review Course for Residents “at Risk”
Authors: Aeder Lita , Fogel Joshua , Schaeffer Henry
Published: January 2010

Objective: There is a correlation between American Board of Pediatrics In-Training and General Pediatrics Certifying Examination scores. A course targeted mainly for residents “at-risk” based on in-training scores may improve the outcome of the certification exam. The objective of the study was to evaluate the impact of a board review course on pediatric board certification scores, particularly for residents at-risk. Methods: Residents “at-risk” taking the course (Yes) were compared to residents not taking the course who were not at-risk (No) as well as to a cohort of residents predating the onset of the course with mixed risk (Comparison). Analyses compared board exam scores and passing rates in the three groups and in the subcategory of residents who scored ≤300 on the in-training exam in each group. Results: Standard scores and pass rates were higher for the residents not at risk, middle for residents of mixed risk and lowest for residents at risk. When analyzing the subset of scores for those with in-training score of <300, the scores were higher for the residents in the course than those who never took it. Also, residents with in-training score of <300 achieved higher average point score gains when comparing the certification exam to their last in-training score. Linear regression analysis showed that not delaying board certification, third year in-training scores and taking the board review course were significantly associated with higher board certification scores. Conclusions: Pediatric residents at risk for not passing their Pediatric board certification exams benefited from a board review course.