bluuebunny/crossref_metadata_2025 huggingface dataset:
Wheel–rail impact and the dynamic forces at discrete supports of rails in the presence of singular rail surface defects
Authors: Zhao X , Li Z , Liu J
Published: August 2011

A validated three-dimensional (3D) transient finite element model is used to evaluate the wheel–rail impact at singular rail surface defects and the resulted high-frequency dynamic forces at the discrete supports of the rail. A typical ballasted railway track is modeled, in which the supports of the rail are composed of the fastenings, the sleepers, and the ballast. The primary suspension of the vehicle is considered. To include all the important eigen characteristics of the vehicle–track system, the wheel set, the rail, and the sleepers are all meshed using 3D solid elements. The transient wheel–rail rolling contact is solved using a surface-to-surface contact algorithm in the time domain. By simulating the steady-state rolling of a wheel set on a smooth rail, the vertical force distribution at the discrete supports is first compared with Zimmermann solution. Afterward, rail surface defects are applied to calculate the resulted dynamic forces at thewheel–rail interface and at the discrete supports of the rail under different rolling speeds. The obtained dynamic responses confirm the necessity of using such a detailed model for the investigations.
Effect of tube lip thickness on the performance of Hartmann–Sprenger tubes
Authors: Vinoth B R , Throvagunta P , Rathakrishnan E
Published: August 2011

Experiments were carried out to investigate the effect of tube lip thickness on Hartmann--Sprenger (HS) tones in the moderately underexpanded conditions. It is found that the generation of jet regurgitant (JRG) tones and screech tones are independent of the tube lip thickness. The first shock cell length ( L c) and the correctly expanded speed of sound ( a j) are found to be the characteristic scale for length and velocity, respectively for both JRG and screech tones in the moderately underexpanded jets. The average normalized frequency, f L/ a j ( L is the length of the HS tube) of the JRG tones is 0.25. Two new families of tones are generated by the increase of tube lip thickness. The frequency of tones in one of the two families is the same as the general impingement (IG) tones generated by the supersonic jet impinging on flat plates. The frequency of tones of the other family (induced quarter wave) is equal to the frequency of the quarter wave mode of the tube and these tones are induced by IG tones. The end wall pressure (a measure of compression of the residual fluid) is decreased when the IG tone is present together with the JRG tone. Feedback experiments showed that an acoustic feedback to the nozzle has a role in the self-excitation of screech tones and IG tones but their self-excitation mechanism are found to be different. There is no role of an acoustic feedback in the self-excitation of JRG tones.
Large eddy simulation of a compressor cascade and the influence of spanwise domain
Authors: McMullan W A , Page G J
Published: August 2011

A controlled diffusion compressor cascade is studied using large eddy simulation (LES). The aim of this study is to assess the capability of LES to be used in an industrial context. The Reynolds number is approximately 700 000 based on chord length and inlet velocity. A ‘thin-slice’ representation of the cascade is used as the reference grid, and the influence of a narrow span is studied by comparison simulations with a domain that has a span five times larger than the thin-slice grid. While the instantaneous flow-fields of the thin-slice and wide-domain simulations are qualitatively similar, the thin-slice simulations suffer from flow confinement problems caused by the imposition of the narrow span. The non-unity axial velocity density ratio of the flow enforces the use of inviscid wall spanwise boundaries, which have a parasitic influence on the development of the flow in the thin-slice simulations. The resultant data obtained from the thin-slice simulations are therefore compromised and the computed loss estimation is considered unreliable. However, when comparing mean quantities such as surface pressure and boundary layer growth the narrow does give reasonable predictions. While the inviscid spanwise walls also affect the flow near the boundaries in the wide domain simulations, there is sufficient region of span from which reliable flow data and loss estimations can be obtained. For blade flows at off-design conditions, a span of 20 per cent of the blade chord is sufficient to give good agreement with experimental data. This incurs a computational cost that may be too high to incorporate parametric LES studies into the design cycle of turbomachinery components with current computers.
Robust fault-tolerant tracking control for a near-space vehicle using a sliding mode approach
Authors: Jiang B , Xu Y , Shi P , Gao Z
Published: August 2011

In this study, a flight fault-tolerant control scheme based on an adaptive sliding mode technique is proposed. First, a control allocation of a near-space vehicle (NSV) attitude dynamics is analysed, and actuator fault modelling is introduced. Then, a modified sliding model tracking control approach, using a continuous strategy of integral sliding mode control, is designed to improve the position tracking precision. This scheme can solve the chattering problem without loss of robustness and control accuracy. Actuator fault and unmeasurable external disturbances are compensated for by an integral action term. To verify the effectiveness of the proposed control scheme, a numerical simulation is performed for an NSV attitude system, which is a non-linear aircraft model with six degrees of freedom. Simulation results demonstrate that the closed-loop system has good performance in spite of the actuator fault and system disturbances.
Design of HyQ – a hydraulically and electrically actuated quadruped robot
Authors: Semini C , Tsagarakis N G , Guglielmino E , Focchi M , Cannella F , Caldwell D G
Published: August 2011

A new versatile hydraulically powered quadruped robot ( HyQ) has been developed to serve as a platform to study not only highly dynamic motions, such as running and jumping, but also careful navigation over very rough terrain. HyQ stands 1 m tall, weighs roughly 90 kg, and features 12 torque-controlled joints powered by a combination of hydraulic and electric actuators. The hydraulic actuation permits the robot to perform powerful and dynamic motions that are hard to achieve with more traditional electrically actuated robots. This paper describes design and specifications of the robot and presents details on the hardware of the quadruped platform, such as the mechanical design of the four articulated legs and of the torso frame, and the configuration of the hydraulic power system. Results from the first walking experiments are presented, along with test studies using a previously built prototype leg.
Comparison of methods to determine variations in unstrained unit cell parameter across welds
Authors: Altenkirch J , Peel M J , Steuwer A , Withers P J
Published: August 2011

Many alloys undergo complex changes in local chemistry in the vicinity of weldments due to the thermal excursion during welding. The resulting changes in solute concentrations can lead to significant local variations in the unstrained unit cell parameter which, if not accounted for, can lead to serious error when determining residual stress by diffraction methods. Age-hardening aluminium alloys are particularly susceptible to such effects. The present paper compares three methods (plane stress assumption, sin2ψ method, and comb correction method) for evaluating the stress-free unit cell parameter variation for friction stir welds in AA7449-W51 plates of two different thicknesses. All three methods gave comparable results for thin (5 mm) sheet, but for the thicker (12.2 mm) plate the results calculated on the basis of the plane stress assumption diverged from the other two, largely because in this case the other methods indicate there to be a significant triaxiality of stress. In the example cases, hardness and unstrained unit cell parameter variations were found to be strongly correlated across the welds. The advantages and disadvantages of the three methods are compared.
Holocene evolution of Huangqihai Lake in semi-arid northern China based on sedimentology and luminescence dating
Authors: Zhang JingRan , Jia YuLian , Lai ZhongPing , Long Hao , Yang LinHai
Published: August 2011

The pattern of Holocene palaeoclimatic change in arid-semiarid northern China is debated. The terminal Huangqihai Lake is located at the northern margin of the modern East Asian summer monsoon and sensitive to climate change. We present here a sedimentary section from Huangqihai lake basin which comprises lacustrine and fluvial deposits and is about 8–9 m above the present lake level. Quartz optically stimulated luminescence (OSL) dating was employed to construct the chronology of the section. Based on the OSL chronology and the sedimentological and granulometric analysis, we conclude that (1) the Huangqihai Lake experienced a humid climate during the early part of the Holocene (from c. 10.2 ± 1.0 to 6.7 ± 0.7 ka) with a persistent and stable high lake level; (2) the lake level began to decline indicating aridification between 8.7 ± 0.8 ka and 6.7 ± 0.7 ka, and the climate was drier and variable after 6.7 ± 0.7 ka compared with that of before; (3) from 2.2 ± 0.2 to 0.93 ± 0.07 ka the climatic conditions were highly variable and continuously deteriorating, and the lake was turned into a playa for most of the time. In summary, the climate showed a general drying trend from the early Holocene to the late Holocene.
Knowledge About Sexually Transmitted Infections (STIs) and Attitudes Toward Female Sex Workers With STI Symptoms Among Health Care Providers in Laos
Authors: Phrasisombath Ketkesone , Thomsen Sarah , Hagberg Jan , Sychareun Vanphanom , Faxelid Elisabeth
Published: August 2011

This study aimed to assess the knowledge and attitudes among health care providers (HCPs) providing sexually transmitted infection (STI) service to female sex workers (FSWs). A cross-sectional survey was performed in 6 districts along Road 9, traversing Savannakhet province from Thailand to Vietnam. In total, 244 HCPs providing STI services were interviewed. In all, 54% of respondents had no STI training despite providing STI treatment. Misperceptions of STI causes, transmission routes, and symptoms were common among respondents. Attitudes differed neither between male and female respondents nor between those who had or had not received STI training. A higher proportion of pharmacists/drug sellers (68%) had negative attitudes followed by medical doctors (59%) and nurse/midwives (55%). The proportion of herbalists with negative attitudes (53%) was less in comparison with the other professionals. To improve the quality of STI services and to enhance FSWs’ access to health care services, educational improvements of HCPs’ knowledge about STIs and their attitudes are needed.
Relationship Between Prevalence of Childhood Obesity in 17-Year-Olds and Socioeconomic and Environmental Factors
Authors: Sakai Rie
Published: August 2011

To investigate the association between childhood obesity and neighborhood-level socio-economic and environmental factors in Japan. The prevalence of childhood obesity in 2008 was obtained from annual reports of the School Health Survey. The following 12 factors were publicly available: income per person, ratio of people completing up to college or university education, population density, total length of roads per square kilometer, number relative to the population of food and drink stores, restaurants, large-scale retail stores, convenience stores, passenger cars, traffic accidents, criminal offenses, and death by accidents. The ratio of people completing up to college or university education was inversely associated with obesity in boys and girls. No association was found between obesity and the other factors examined. An inverse association was shown between educational level and childhood obesity in both boys and girls. Further studies integrating associations between childhood obesity and neighborhood-level factors are needed.
Culturally Safe Nursing Research
Authors: McCleland Ann
Published: August 2011

Cultural safety is a familiar concept used in nursing education, research, and practice. It is also an important concept in nursing research and is one way of providing safety for indigenous participants and researchers, but it raises several questions, for one, who is the most appropriate person or persons to work in partnership with indigenous participants in research? Furthermore, who is the most appropriate person to critique the academic research of an indigenous researcher? These questions are usually not considered when ethic committees review a researcher’s application for research approval or funding. This article defines cultural safety and the concern that indigenous students put aside their culture when they commit to study within an education steeped in Westernized thinking. It discusses the decolonization of research and the part that nonindigenous researchers play within an indigenous research project. This article also outlines the application of an indigenous methodology and method in a project that enabled participants and the researcher to develop a culturally safe process in the form of a metaphorical whanau (family). This was also reflected in the findings of the project when Maori students within a bachelor of nursing program formed whanau groups, which enabled them to succeed in their study.
Design of Extendable Chord Sections for Morphing Helicopter Rotor Blades
Authors: Barbarino Silvestro , Gandhi Farhan , Webster Steven D.
Published: August 2011

Chord extension morphing of helicopter rotors has recently been shown to be highly beneficial for stall alleviation, with the ability to reduce power near the envelope boundaries and increase maximum gross weight, altitude, and speed capability of the aircraft. This article presents a morphing mechanism to extend the chord of a section of the helicopter rotor blade. The region aft of the leading-edge spar contains a morphing cellular structure. In the compact state, the edge of the cellular structure aligns with the trailing edge of the rest of the blade. When the morphing cellular structure is in the extended state, the chord of that section of the blade is increased by 30%. In transitioning from compact to extended states, the cellular structure slides along the ribs which define the boundaries of the morphing section in the spanwise direction. The cellular section has mini-spars running along the spanwise direction to attach the flexible skin and provide stiffness against camber-like deformations due to aerodynamic loads. This article presents a finite element analysis and design of the morphing cellular structure, ensuring that the local strains in the elastic ligaments of the cellular structure do not exceed the maximum allowable, even as the section undergoes a large global strain. The morphing cellular structure itself is designed to be stiff enough to support the pre-stretched skin attached to its surfaces. Various methods of flexible skin attachment to the morphing substructure, and their ramifications, are considered. A model of a blade section is fabricated and shown to undergo chord morphing, as designed.
Prognostics of Failures in Embedded Planar Capacitors using Model-Based and Data-Driven Approaches
Authors: Alam Mohammed A. , Azarian Michael H. , Osterman Michael , Pecht Michael
Published: August 2011

This paper presents the application of model-based and data-driven approaches for prognostics of failures in embedded planar capacitors. An embedded planar capacitor is a thin laminate that serves both as a power/ground plane and as a parallel plate capacitor in a multilayered printed wiring board. These capacitors have gained importance with an increase in the operating frequency and a decrease in the supply voltage in electronic circuits since they can enable miniaturization of electronic circuits as well as improved electrical performance. In next generation electronic circuits, embedded planar capacitors will be crucial in communication, automotive, military, medical, and space applications. The capacitor laminate used in this study consisted of an epoxy-barium titanate nanocomposite dielectric sandwiched between Cu layers. Three electrical parameters, capacitance, dissipation factor, and insulation resistance, were monitored in situ during testing under elevated temperature and voltage-aging conditions. The failure modes observed were a sharp drop in insulation resistance and a gradual decrease in capacitance. An approach to model the time-to-failure associated with these failure modes is presented in this paper. Further, a data-driven technique known as the Mahalanobis distance method is also investigated for early detection of these failures.
Postmortem Confidentiality: An Ethical Issue
Authors: Bradley Loretta J. , Hendricks Bret , Kabell Douglas R.
Published: August 2011

In an era of increased need and expectation for confidentiality, the counseling record of the deceased client challenges confidentiality. Using ethical codes and legal mandates, the authors explore whether the counseling record of a deceased client should be released when the client’s will and the client’s counseling records are silent on this issue.
Intermediate-affinity interleukin-2 receptor expression predicts CD56bright natural killer cell expansion after daclizumab treatment in the CHOICE study of patients with multiple sclerosis
Authors: Sheridan James P , Zhang Ying , Riester Katherine , Tang Meina T , Efros Lyubov , Shi Jia , Harris Jeffrey , Vexler Vladimir , Elkins Jacob S
Published: August 2011

Objective: The objective of this study was to evaluate whether interleukin-2 (IL-2) receptor expression on CD56bright natural killer (NK) cells predicted CD56bright NK cell expansion and therapeutic response to daclizumab (DAC) in multiple sclerosis (MS).

Methods: DAC exposure, CD56bright NK cell counts, IL-2 receptor alpha (CD25) and beta (CD122) subunits, and new or enlarged lesions on brain MRI were measured in 64 subjects in a pharmacokinetic/pharmacodynamic substudy of the phase 2 CHOICE trial at multiple time points. Peripheral blood mononuclear cell (PBMC) samples were obtained from healthy subjects to assess the relationship among DAC treatment, intermediate affinity IL-2 signaling, and CD56bright NK cell expansion.

Results: Increased CD56bright NK cell counts in DAC/interferon beta (IFNβ)-treated subjects were observed by day 14, the first post-dosing time point (mean [SD] ln{CD56bright NK cell count}: DAC high/IFNβ, 2.01 [1.25]; DAC low/IFNβ, 2.29 [1.06]; placebo/IFNβ, 1.01 [1.03]; adjusted p = 0.003), and persisted throughout the treatment period. Higher DAC dose predicted a faster rate of CD56bright NK cell expansion ( p < 0.001), but individual subjects’ increases in CD56bright NK cells from baseline levels were only weakly correlated with DAC exposure ( r2 = 0.167). Higher expression of the intermediate-affinity IL-2 receptor subunit (CD122) on CD56bright NK cells at baseline predicted fewer new gadolinium-enhanced (Gd+) lesions during the treatment period (1.77 vs. 0.62 adjusted mean new Gd+ lesions during weeks 8–24, lowest vs. highest quartile of percentage CD122+ CD56bright NK cells; p = 0.033) and a greater increase in CD56bright NK cell counts at the end of DAC dosing ( p = 0.029).

Conclusion: CD56bright NK cell expansion after DAC treatment appears to reflect individual differences in the capacity for intermediate-affinity IL-2 signaling and could provide a basis for predicting clinical response to DAC in MS.
Unstable islands and bifurcation analysis in a spindle milling system supported by ball bearings
Authors: Gao S H , Meng G
Published: August 2011

This article examines the chatter isolated islands and non-linear responses of a spindle milling system supported by ball bearings. Isolated islands of chatter vibration, which are induced by the non-linear non-smooth ball bearing Hertz contacts, can be found exist in milling processes. The existence of islands of chatter vibration phenomenon is also confirmed by the bifurcation analysis in this article. The stability trends are then examined for several up-milling and down-milling machining processes, respectively, with varying machine tool radial immersions. Results show that, with the influences of the non-linear non-smooth ball bearing Hertz contacts, the milling stability charts present very complex dynamic properties and appear more irregular unstable chatter islands than those induced by the tool helix angles. It is believed that this study complements the researches of chatter vibrations for milling systems.
Focus Group Evaluation of “Secret Feelings”
Authors: Cabassa Leopoldo J. , Contreras Sandra , Aragón Rebeca , Molina Gregory B. , Baron Melvin
Published: August 2011

In this study, the authors examined reactions of Latino adults with limited English proficiency (LEP) to a culturally and linguistically adapted depression fotonovela, titled “Secret Feelings.” Fotonovelas are popular health education tools that use posed photographs, text bubbles with simple text, and dramatic narratives to engage audiences and raise their awareness and knowledge about specific health issues. Four focus groups ( N = 32) were conducted at an adult school program (e.g., GED classes). Content analysis was used to generate themes from transcripts and memos. “Secret Feelings” was viewed as an entertaining, engaging, and educational tool that helped combat stigma toward depression and its treatments in the Latino community. Despite learning about depression, participants reported they wanted more information about the causes of depression, the process of recovery, and felt that the story did not shift their apprehensions toward antidepressants. The findings suggest that “Secret Feelings” is a promising depression literacy tool for Latinos with LEP that can raise awareness and knowledge about depression and its treatments, reduce stigma toward depression and antidepressant medications, and model appropriate help-seeking behaviors.
An Early Mobilization Protocol Successfully Delivers More and Earlier Therapy to Acute Stroke Patients
Authors: van Wijk Renske , Cumming Toby , Churilov Leonid , Donnan Geoffrey , Bernhardt Julie
Published: August 2011

Background. The optimal physical therapy dose in acute stroke care is unknown. The authors hypothesized that physical therapy would be significantly different between treatment arms in a trial of very early and frequent mobilization (VEM) and that immobility-related adverse events would be associated with therapy dose. Methods. This study was a single-blind, multicenter, randomized control trial. Patients admitted to a stroke unit <24 hours of stroke randomized to standard care (SC) or intervention, SC plus additional early out-of-bed therapy (VEM). Timing, amount, and type of therapy recorded throughout the trial. Adverse events were recorded to 3 months. Results. A total of 71 patients (SC n = 33, VEM n = 38) received 788 therapy sessions in the first 2 weeks of stroke. Schedule (hours to first mobilization, dose per day, frequency and session duration) and nature (percentage out-of-bed activity) of therapy differed significantly between groups ( P ≤ .001 for all components). Mobilization was earlier, happened on average 3 times per day in those receiving VEM, with the proportion of out-of-bed activity double in VEM session (median SC 42.5%, VEM 85.5%). SC consisted of 17 minutes of occupational and physiotherapy per day and was the same between groups. Number of immobility-related adverse events 3 months poststroke was not associated with therapy dose or frequency. Conclusions. The authors detailed usual care and intervention therapy provided to patients from admission to 14 days after stroke. The therapy schedule was markedly different in the intervention arm, but whether this schedule reduces complications or improves outcome is unknown.
Polypyrrole/oligonucleotide nanocomposite film: steric effect on DNA hybridization
Authors: Jiang J-H , Li Y , Wang J , Paul Sung K-L
Published: August 2011

This paper presents evidence and some preliminary explanation for the existence of a steric effect in polypyrrole/oligonucleotide (PPy/ODN) nanocomposite film, which may be responsible for the high electrochemical sensing performance of that nanofilm when being used in DNA hybridization detection. When hybridization occurs in this nanocomposite film, the steric effect in the immediate interface of the hybrid film can damp the ion-flux penetrating through this interface, thus resulting in the signal differentiation on the electrode electrochemical property. Electrochemical cyclic voltammetry (CV) combined with atomic force microscope (AFM) were utilized to clarify the hindering mechanism occurring on such interface. Furthermore, the hybridization reaction of ODN probes in the hybrid PPy/ODN film with their complementary DNA sequences was measured via CV, with the target ODN concentrations as low as 5×10−18 mol/L. Under optimized hybridization conditions the sensor response was almost linear, with the logarithm of the target ODN concentration ranging from 1×10−18 to 1×10−11 mol/L. These results may be useful in the development of a much simpler label-free DNA sensor based on the PPy/ODN nanocomposite film.
Probabilistic reliability assessment in operation planning
Authors: Lima J M , Schilling M Th , Lourenço E M
Published: August 2011

The Brazilian power grid has traditionally been designed and operated using a set of deterministic reliability criteria. They have played an important role in the design and operation of the Brazilian bulk power system for decades. However, they tend to use available resources less optimally and over-book facilities in the context of transmissions capacity. With regard to the approval of scheduled maintenance of transmission equipment on the basic grid, the main deterministic criterion adopted by the Brazilian Independent System Operator (ISO) is the n − 2 criterion. The current article proposes replacement of the deterministic n − 2 criterion by a probabilistic criterion to allow for more scheduled maintenance during medium load workdays, without significantly increasing the risk level of the system. The expected result of implementing our recommended criterion is a reduction in operations and maintenance costs, which should in turn reduce the electricity rates paid by end users.
Management of fungal lung disease in the immunocompromised
Authors: Islam Anowara , Mody Christopher H.
Published: August 2011

Pulmonary mycoses are among the most feared infections encountered in immunocompromised patients. The problem is amplified by the increasing numbers of chronically immunocompromised patients that have substantially increased both the prevalence and clinical severity of infections caused by fungi. Moreover, fungal infections in this patient population pose challenges in diagnosis and management. Fortunately, recent advances in diagnostics and antifungal therapy, and their direct application to specific diseases, provide important new approaches to this complex and often seriously ill patient population. In this article we review the commonly occurring pulmonary fungal infections in the immunocompromised population with a particular focus on their management.
Selective-serotonin reuptake inhibitors for the treatment of hypersensitive esophagus
Authors: Viazis Nikos , Karamanolis George , Vienna Eleni , Karamanolis Dimitrios G.
Published: August 2011

In patients with proton-pump inhibitor (PPI) resistant reflux symptoms, ambulatory 24 h pH impedance monitoring can be used to assess whether a relationship exists between symptoms and reflux episodes. Using this technique it has been suggested that patients with typical reflux symptoms and a normal upper endoscopy should be subclassified as follows: normal endoscopy and abnormal distal acid esophageal exposure (patients with acid reflux); normal endoscopy, with normal distal acid esophageal exposure and a positive symptom association for either acid or nonacid reflux (patients with hypersensitive esophagus); and normal endoscopy, normal distal acid esophageal exposure and a negative symptom association for acid and nonacid reflux (patients with functional heartburn). Although for patients with a normal endoscopy and abnormal distal acid esophageal exposure more aggressive acid suppression can be recommended, managing patients with hypersensitive esophagus and functional heartburn remains a real challenge.

Therefore, investigators have evaluated the role of tricyclic antidepressants or selective-serotonin reuptake inhibitors (SSRIs) in influencing esophageal perception. Imipramine has been shown to decrease pain perception in healthy male volunteers and improve symptoms of patients with chest pain and normal coronary angiograms. Trazodone improved symptoms in patients with esophageal contraction abnormalities, while administration of SSRIs lowered chemical and mechanical sensitivity and benefited patients with diffuse esophageal spasm. Furthermore, in a recent study conducted by our group, citalopram administered once daily for 6 months was effective in a select group of patients with hypersensitive esophagus, suggesting that there is a role for SSRIs in the treatment of this disorder.
Novel cytokine signaling pathways in inflammatory bowel disease: insight into the dichotomous functions of IL-33 during chronic intestinal inflammation
Authors: Pastorelli Luca , De Salvo Carlo , Cominelli Marissa A. , Vecchi Maurizio , Pizarro Theresa T.
Published: August 2011

In 2010, four independent groups almost simultaneously reported the association of the novel interleukin-1 (IL-1) family member, IL-33, with inflammatory bowel disease (IBD). The findings were remarkably consistent and demonstrated that IL-33 is markedly upregulated in, and specific to, ulcerative colitis (UC). In addition, although a variety of gut-associated immune cell subsets express IL-33, the primary source appears to be the intestinal epithelium. IL-33’s receptor, ST2, a formerly orphaned IL-1 receptor-related protein, was also found to be increased in UC patients, although the cellular source of ST2 appears to be somewhat more ambiguous. In fact, emerging evidence indicates that the IL-33/ST2 axis plays a critical role in several other chronic inflammatory and immune disorders. In the gut, IL-33 has been shown to be important in the clearance of intestinal parasites, and inducing epithelial cell hyperplasia, mucus production and mucosal eosinophilic infiltration. However, despite the established trend of increased IL-33 and ST2 expression during IBD, specifically UC, the precise pathophysiologic relevance of these findings has yet to be determined. Interestingly, IL-33 has the ability to potentiate pathogenic Th2 and Th17 responses in gut-associated lymphoid tissues, while also promoting healing of damaged mucosa following inflammatory insults. Indeed, further mechanistic studies are warranted to confirm the possible dichotomous functions of IL-33 during chronic intestinal inflammation and better define its precise role in the pathogenesis of IBD. Herein, we discuss what is currently known about IL-33/ST2 in the gut and speculate as to the potential role of the IL-33/ST2 system in IBD.
Using infection prevention data for improvement: the infection prevention control team as a clinical support micro-system
Authors: Curran Evonne Teresa
Published: August 2011

Process and outcome data are essential to evaluate the effectiveness of infection prevention and control teams (IPCT). Data are used for: the identification of possible outbreaks, surveillance of healthcare associated infections, monitoring the epidemiology of alert organisms, monitoring IPC practices, creating arguments for the need to change practices, and demonstrating whether the changes in practices have been effective in improving outcomes. Today the IPCT can be data rich without being intelligence rich. It is critical that IPCT are able to generate targets for improving patient safety. Also the IPCT must be able to easily read, interpret and discuss data so that the effects of change can be measured, communicated and understood. This paper details a 10-point plan to make straightforward the use of data in creating arguments for, and the measuring of, system change to drive improvements and reduce infection outcomes.
When Common Identities Reduce Between-Group Helping
Authors: Leeuwen Esther van , Mashuri Ali
Published: August 2011

Emphasizing a common group identity is often suggested as a way to promote between-group helping. But recently, researchers have identified a set of strategic motives for helping other groups, including the desire to present the own group as warm and generous. When the motive for helping is strategic, a salient common identity should reduce the willingness to help another group, because the help no longer communicates a quality of the ingroup (only of the common group). The authors tested this hypothesis in two experiments, in which they assessed beliefs about helping (Study 1) and actual helping through behavioral observation (Study 2). The results fully supported the predictions, demonstrating that a common identity is not a universal tool for the promotion of prosocial behavior. The studies also illustrate the strategic nature of between-group helping, in which acts that appear prosocial on the surface are in fact intended to enhance the ingroup’s image.
Molecular adaptation in flowering and symbiotic recognition pathways: insights from patterns of polymorphism in the legume Medicago truncatula
Authors: De Mita Stéphane , Chantret Nathalie , Loridon Karine , Ronfort Joëlle , Bataillon Thomas
Published: August 2011

Background

We studied patterns of molecular adaptation in the wild Mediterranean legume Medicago truncatula. We focused on two phenotypic traits that are not functionally linked: flowering time and perception of symbiotic microbes. Phenology is an important fitness component, especially for annual plants, and many instances of molecular adaptation have been reported for genes involved in flowering pathways. While perception of symbiotic microbes is also integral to adaptation in many plant species, very few reports of molecular adaptation exist for symbiotic genes. Here we used data from 57 individuals and 53 gene fragments to quantify the overall strength of both positive and purifying selection in M. truncatula and asked if footprints of positive selection can be detected at key genes of rhizobia recognition pathways.

Results

We examined nucleotide variation among 57 accessions from natural populations in 53 gene fragments: 5 genes involved in nitrogen-fixing bacteria recognition, 11 genes involved in flowering, and 37 genes used as control loci. We detected 1757 polymorphic sites yielding an average nucleotide diversity (pi) of 0.003 per site. Non-synonymous variation is under sizable purifying selection with 90% of amino-acid changing mutations being strongly selected against. Accessions were structured in two groups consistent with geographical origins. Each of these two groups harboured an excess of rare alleles, relative to expectations of a constant-sized population, suggesting recent population expansion. Using coalescent simulations and an approximate Bayesian computation framework we detected several instances of genes departing from selective neutrality within each group and showed that the polymorphism of two nodulation and four flowering genes has probably been shaped by recent positive selection.

Conclusion

We quantify the intensity of purifying selection in the M. truncatula genome and show that putative footprints of natural selection can be detected at different time scales in both flowering and symbiotic pathways.
Large-scale RNAi screen of G protein-coupled receptors involved in larval growth, molting and metamorphosis in the red flour beetle
Authors: Bai Hua , Zhu Fang , Shah Kapil , Palli Subba Reddy
Published: August 2011

Background

The G protein-coupled receptors (GPCRs) belong to the largest superfamily of integral cell membrane proteins and play crucial roles in physiological processes including behavior, development and reproduction. Because of their broad and diverse roles in cellular signaling, GPCRs are the therapeutic targets for many prescription drugs. However, there is no commercial pesticide targeting insect GPCRs. In this study, we employed functional genomics methods and used the red flour beetle, Tribolium castaneum, as a model system to study the physiological roles of GPCRs during the larval growth, molting and metamorphosis.

Results

A total of 111 non-sensory GPCRs were identified in the T. castaneum genome. Thirty-nine of them were not reported previously. Large-scale RNA interference (RNAi) screen was used to study the function of all these GPCRs during immature stages. Double-stranded RNA (dsRNA)-mediated knockdown in the expression of genes coding for eight GPCRs caused severe developmental arrest and ecdysis failure (with more than 90% mortality after dsRNA injection). These GPCRs include dopamine-2 like receptor (TC007490/D2R) and latrophilin receptor (TC001872/Cirl). The majority of larvae injected with TC007490/D2R dsRNA died during larval stage prior to entering pupal stage, suggesting that this GPCR is essential for larval growth and development.

Conclusions

The results from our study revealed the physiological roles of some GPCRs in T. castaneum. These findings could help in development of novel pesticides targeting these GPCRs.
Role of epithelial integrin-linked kinase in promoting intestinal inflammation: effects on CCL2, fibronectin and the T cell repertoire
Authors: Assi Kiran , Patterson Scott , Dedhar Shoukat , Owen David , Levings Megan , Salh Baljinder
Published: August 2011

Background

The role of integrin signaling in mucosal inflammation is presently unknown. Hence, we aimed to investigate the role of epithelial-derived integrin-linked kinase (ILK), a critical integrin signaling intermediary molecule, in colonic inflammation.

Methods

Conditional intestinal epithelial cell ILK knockout mice were used for assessment of acute and chronic dextran sodium sulfate (DSS) -induced colitis. Disease activity was scored using standard histological scoring, mucosal cytokines were measured using ELISA, chemokines were determined using reverse-transcription polymerase chain reaction, as well as Q-PCR, and intracellular cytokine staining performed using FACS analysis.

Results

In both acute and chronic DSS-induced colitis, compared to wild-type mice, ILK-ko mice exhibit less weight loss, and have reduced inflammatory scores. In anin vitromodel system using HCT116 cells, we demonstrate that si-RNA mediated down-regulation of ILK results in a reduction in monocyte chemoattractant protein 1 (MCP1, CCL2) chemokine expression. A reduction in CCL2 levels is also observed in the tissue lysates of chronically inflamed colons from ILK-ko mice. Examination of mesenteric lymph node lymphocytes from ILK-ko mice reveals that there is a reduction in the levels of IFN gamma using intracellular staining, together with an increase in Foxp3+ T regulatory cells. Immunohistochemistry demonstrates that reduced fibronectin expression characterizes the inflammatory lesions within the colons of ILK-ko mice. Intriguingly, we demonstrate that fibronectin is directly capable of downregulating T regulatory cell development.

Conclusions

Collectively, the data indicate for the first time that ILK plays a pro-inflammatory role in intestinal inflammation, through effects on chemokine expression, the extracellular matrix and immune tolerance.
Waist circumference and risk of elevated blood pressure in children: a cross-sectional study
Authors: Choy Cheuk-Sing , Chan Wan-Yu , Chen Ta-Liang , Shih Chun-Chuan , Wu Li-Chu , Liao Chien-Chang
Published: August 2011

Background

Increasing childhood obesity has become a major health threat. This cross-sectional study reports associations between schoolchildren's waist circumference (WC) and risk of elevated blood pressure.

Methods

We measured height, weight, neck and waist circumference, and blood pressure in regular health examinations among children in grade 1 (ages 6-7 years) at six elementary schools in Taipei County, Taiwan. Elevated blood pressure was defined in children found to have mean systolic or diastolic blood pressure greater than or equal to the gender-, age-, and height-percentile-specific 95th-percentile blood pressure value.

Results

All 2,334 schoolchildren were examined (response rate was 100% in the six schools). The mean of systolic and diastolic blood pressure increased as WC quartiles increased (p < 0.0001). The prevalence of elevated blood pressure for boys and girls within the fourth quartile of waist circumference was 38.9% and 26.8%, respectively. In the multivariate logistic regression analyses, the adjusted odds ratios of elevated blood pressure were 1.78 (95% confidence interval [CI] = 1.13-2.80), 2.45 (95% CI = 1.56-3.85), and 6.03 (95% CI = 3.59-10.1) for children in the second, third, and fourth waist circumference quartiles compared with the first quartile. The odds ratios for per-unit increase and per increase of standard deviation associated with elevated blood pressure were 1.14 (95% CI = 1.10-1.18) and 2.22 (95% CI = 1.76-2.78), respectively.

Conclusions

Elevated blood pressure in children was associated with waist circumference. Not only is waist circumference easier to measure than blood pressure, but it also provides important information on metabolic risk. Further research is needed on effective interventions to identify and monitor children with increased waist circumference to reduce metabolic and blood pressure risks.
Spatiotemporal expression of SERPINE2 in the human placenta and its role in extravillous trophoblast migration and invasion
Authors: Chern Schu-Rern , Li Sheng-Hsiang , Chiu Chien-Ling , Chang Hsiao-Ho , Chen Chih-Ping , Tsuen Chen Edmund I
Published: August 2011

Background

SERPINE2, one of the potent serpins belonging to the plasminogen activator (PA) system, is involved in the tissue remodeling. We previously demonstrated the expression patterns of Serpine2 in the mouse placenta and uterus, indicating that Serpine2 is a major PA inhibitor in the placenta and uterus during the estrous cycle, pregnancy, and lactation. In this study, we further investigated the expression pattern of SERPINE2 in the human placenta and explored possible functional roles of SERPINE2 in regulating trophoblast activity.

Methods

Placental tissues from various trimesters were collected for real-time reverse-transcription polymerase chain reaction quantification. Immunohistochemical staining was performed in placental tissues to assure localization of SERPINE2. SERPINE2 small interfering (si) RNA was applied to suppress its expression in villous explants and extravillous trophoblast-like 3A cells. Subsequent experiments to evaluate SERPINE2 levels, villous outgrowth, trophoblast invasion, and tube formation were performed.

Results

SERPINE2 messenger RNA was detected in the human placenta during pregnancy with the highest levels in the third trimester. The SERPINE2 protein was present in villous syncytiotrophoblasts and trophoblasts of chorionic villi for anti-SERPINE2 immunostaining. Extravillous trophoblasts in the chorionic plate and basal plate confronting the invasive face of anchoring villi were also positive. In most decidual cells, SERPINE2 was observed in the cytoplasm. In addition, fibrinoid deposit was weakly immunoreactive. Introduction of SERPINE2 siRNA into villous explants and trophoblast cells led to significantly reduced villous outgrowth, and trophoblastic migration and invasion. Moreover, capillary-like network formation of 3A cells in Matrigel was greatly attenuated by SERPINE2 siRNA and SERPINE2 antiserum.

Conclusions

These data identify the temporal and spatial SERPINE2 distribution in the human placenta and suggest its possible role in modulating tissue remodeling of extravillous trophoblasts in the placenta during pregnancy.
The immunological potency and therapeutic potential of a prototype dual vaccine against influenza and Alzheimer's disease
Authors: Davtyan Hayk , Ghochikyan Anahit , Cadagan Richard , Zamarin Dmitriy , Petrushina Irina , Movsesyan Nina , Martinez-Sobrido Luis , Albrecht Randy A , García-Sastre Adolfo , Agadjanyan Michael G
Published: August 2011

Background

Numerous pre-clinical studies and clinical trials demonstrated that induction of antibodies to the β-amyloid peptide of 42 residues (Aβ42) elicits therapeutic effects in Alzheimer's disease (AD). However, an active vaccination strategy based on full length Aβ42 is currently hampered by elicitation of T cell pathological autoreactivity. We attempt to improve vaccine efficacy by creating a novel chimeric flu vaccine expressing the small immunodominant B cell epitope of Aβ42. We hypothesized that in elderly people with pre-existing memory Th cells specific to influenza this dual vaccine will simultaneously boost anti-influenza immunity and induce production of therapeutically active anti-Aβ antibodies.

Methods

Plasmid-based reverse genetics system was used for the rescue of recombinant influenza virus containing immunodominant B cell epitopes of Aβ42 (Aβ1-7/10).

Results

Two chimeric flu viruses expressing either 7 or 10 aa of Aβ42 (flu-Aβ1-7 or flu-Aβ1-10) were generated and tested in mice as conventional inactivated vaccines. We demonstrated that this dual vaccine induced therapeutically potent anti-Aβ antibodies and anti-influenza antibodies in mice.

Conclusion

We suggest that this strategy might be beneficial for treatment of AD patients as well as for prevention of development of AD pathology in pre-symptomatic individuals while concurrently boosting immunity against influenza.