scholarly journals Mapping Protective Regions on a Three-Dimensional Model of theMoraxella catarrhalisVaccine Antigen Oligopeptide Permease A

2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Antonia C. Perez ◽  
Antoinette Johnson ◽  
Ziqiang Chen ◽  
Gregory E. Wilding ◽  
Michael G. Malkowski ◽  
...  
Keyword(s):  
Protective Antigen ◽  
Financial Burden ◽  
Three Dimensional ◽  
Immune Serum ◽  
Vaccine Antigen ◽  
Chronic Obstructive ◽  
High Avidity ◽  
Three Dimensional Model ◽  
Content Type ◽  
Oligopeptide Permease

ABSTRACTA vaccine againstMoraxella catarrhaliswould reduce tremendous morbidity, mortality, and financial burden by preventing otitis media in children and exacerbations of chronic obstructive pulmonary disease (COPD) in adults. Oligopeptide permease A (OppA) is a candidate vaccine antigen that is (i) a nutritional virulence factor expressed on the bacterial cell surface during infection, (ii) widely conserved among strains, (iii) highly immunogenic, and (iv) a protective antigen based on its capacity to induce protective responses in immunized animals. In the present study, we show that the antibodies to OppA following vaccination mediate accelerated clearance in animals after pulmonary challenge. To identify regions of OppA that bind protective antibodies, truncated constructs of OppA were engineered and studied to map regions of OppA with surface-accessible epitopes that bind high-avidity antibodies following vaccination. Protective epitopes were located in the N and C termini of the protein. Immunization of mice with constructs corresponding to these regions (T5 and T8) induced protective responses. Studies of overlapping peptide libraries of constructs T5 and T8 with OppA immune serum identified two discrete regions on each construct. These potentially protective regions were mapped on a three-dimensional computational model of OppA, where regions with solvent-accessible amino acids were identified as three potentially protective epitopes. In all, these studies revealed two regions with three specific epitopes in OppA that induce potentially protective antibody responses following vaccination. Detection of antibodies to these regions could serve to guide vaccine formulation and as a diagnostic tool for monitoring development of protective responses during clinical trials.

scholarly journals Expression of the Oligopeptide Permease Operon of Moraxella catarrhalis Is Regulated by Temperature and Nutrient Availability

2015 ◽  
Vol 83 (9) ◽  
pp. 3497-3505 ◽  
Author(s):  
Megan M. Jones ◽  
Timothy F. Murphy
Keyword(s):  
Virulence Factor ◽  
Nutrient Availability ◽  
Moraxella Catarrhalis ◽  
Regulation Of Gene Expression ◽  
Vaccine Antigen ◽  
Chronic Obstructive ◽  
Gene Transcript ◽  
Content Type ◽  
Oligopeptide Permease ◽  
Nutritional Virulence

Moraxella catarrhaliscauses otitis media in children and exacerbations of chronic obstructive pulmonary disease in adults. Together, these two conditions contribute to enormous morbidity and mortality worldwide. The oligopeptide permease (opp) ABC transport system is a nutritional virulence factor important for the utilization of peptides. The substrate binding protein OppA, which binds peptides for uptake, is a potential vaccine antigen, but little was known about the regulation of gene expression. The fiveoppgenesoppB,oppC,oppD,oppF, andoppAare in the same open reading frame. Sequence analysis predicted two promoters, one located upstream ofoppBand one within the intergenic region betweenoppFandoppA. We have characterized the gene cluster as an operon with two functional promoters and show that cold shock at 26°C for ≤0.5 h and the presence of a peptide substrate increase gene transcript levels. Additionally, the putative promoter upstream ofoppAcontributes to the transcription ofoppAbut is not influenced by the same environmental cues as the promoter upstream ofoppB. We conclude that temperature and nutrient availability contribute to the regulation of the Opp system, which is an important nutritional virulence factor inM. catarrhalis.

Three-dimensional analysis of anchored wall with concrete bearing pads

2020 ◽  
Vol 18 (6) ◽  
pp. 1469-1486
Author(s):  
Hamed Arefizadeh ◽  
Hadi Shahir
Keyword(s):  
Design Methodology ◽  
Three Dimensional ◽  
Bending Moments ◽  
Dimensional Model ◽  
Discrete Elements ◽  
Three Dimensional Model ◽  
Content Type ◽  
Finite Element Software ◽  
Internal Forces ◽  
Soldier Pile

Purpose Anchorage with concrete bearing pad is commonly used in Iran for stabilization of excavations because of the ease of construction, less costs and less time consumption than the soldier pile method. In this method, a wall facing which includes the concrete bearing pads at the location of the anchors and a shotcrete layer between the bearing pads is constructed parallel to the excavation operation similar to the nailing method. Design/methodology/approach In this paper, using the finite element software Abaqus, a three-dimensional model of the above-mentioned type of wall is constructed, and the effect of spacing and size of bearing pads on the wall behavior is discussed. Findings According to the obtained results, the size of the concrete bearing pads has little effect on wall deformations, but the internal forces and bending moments developed in the shotcrete layer between the bearing pads are greatly influenced by the bearing pads dimensions and spacing. Originality/value Owing to the discrete elements of the wall facing, the behavior of this system is completely three-dimensional.

Influence of airflow dynamics on vortices in the human nasal cavity

2019 ◽  
Vol 36 (9) ◽  
pp. 3164-3179
Author(s):  
Punjan Dohare ◽  
Amol P. Bhondekar ◽  
Anupma Sharma ◽  
C. Ghanshyam
Keyword(s):  
Numerical Simulations ◽  
Nasal Cavity ◽  
Three Dimensional ◽  
Nasal Airflow ◽  
Nasal Valve ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Flow Rates ◽  
Content Type ◽  
Human Nose

Purpose The purpose of this paper is to understand the effect of airflow dynamics on vortices for different flow rates using the human nose three-dimensional model. Design/methodology/approach Olfaction originates with air particles travelling from an external environment to the upper segment of the human nose. This phenomenon is generally understood by using the nasal airflow dynamics, which enhances the olfaction by creating the vortices in the human nose. An anatomical three-dimensional model of the human nasal cavity from computed tomography (CT) scan images using the MIMICS software (Materialise, USA) was developed in this study. Grid independence test was performed through volume flow rate, pressure drop from nostrils and septum and average velocity near the nasal valve region using a four computational mesh model. Computational fluid dynamics (CFD) was used to examine the flow pattern and influence of airflow dynamics on vortices in the nasal cavity. Numerical simulations were conducted for the flow rates of 7.5, 10, 15 and 20 L/min using numerical finite volume methods. Findings At coronal cross-sections, dissimilar nasal airflow patterns were observed for 7.5, 10, 15 and 20 L/min rate of fluid flow in the human nasal cavity. Vortices that are found at the boundaries with minimum velocity creates deceleration zone in the nose vestibule region, which is accompanied by flow segregation. Maximum vortices were observed in the nasal valve region and the posterior end of the turbinate region, which involves mixing and recirculation and is responsible for enhancing the smelling process. Practical implications The proposed analysis is applicable to design the sensor chamber for electronic noses. Originality/value In this paper, the influence of airflow dynamics on vortices in the human nasal cavity is discussed through numerical simulations.

Measuring service quality in mid-scale hotels

2015 ◽  
Vol 27 (1) ◽  
pp. 87-106 ◽  
Author(s):  
Dennis A Rauch ◽  
Michael Dwain Collins ◽  
Robert D Nale ◽  
Peter B. Barr
Keyword(s):  
Service Quality ◽  
Service Delivery ◽  
Factor Structure ◽  
Factor Model ◽  
Three Dimensional ◽  
Online Reviews ◽  
Three Dimensional Model ◽  
Content Type ◽  
Service Environment ◽  
Customer Perceptions

Purpose – The purpose of this study is to identify an appropriate factor structure that may be utilized to effectively measure a hotel’s performance relative to service quality in a mid-scale setting. Customer perceptions of service quality in mid-scale hotels have largely been ignored; the focus of researchers has been the upscale (4-star) and luxury (5-star) segments. Design/methodology/approach – A 27-item questionnaire is utilized to measure service quality with an initial sample size of over 2,500 respondents. Principle component analysis is utilized to determine the factor structure and regression analysis to determine which factors may serve as predictors of a hotel’s ability to meet customers’ expectations and to provide value. Findings – A three-dimensional model emerged from the data, consistent with the theorizing of Rust and Oliver (1994), which includes the service product, service delivery and service environment. The service environment is the strongest predictor of a hotel’s ability to meet guests’ expectations and to provide guests with value within this context, which is inconsistent with findings in upscale and luxury hotels. Research limitations/implications – The generalizability of this research may be challenged, as the study was conducted within the context of an oceanfront resort destination dominated by leisure travelers; however, the study may be replicated in additional settings to determine if a similar bundling of service quality attributes occurs in other mid-scale settings including business hotels, as well as economy hotels. Practical implications – A three-factor model may be more appropriate for assessing service quality in a mid-scale (3-star) environment. In this setting, the service environment and service product may be more important measures of service quality than service delivery. This is an important finding, as many mid-scale and select-service, as well as new mid-scale, lifestyle hotel concepts, attempt to drive profitability by deemphasizing service delivery or by utilizing technology to facilitate service delivery. These findings may also assist operators of mid-scale hotels in improving guests’ perceptions of quality, which has been found to increase perceived value and may positively influence purchase or revisit intentions (Kashyap and Bojanic, 2000). Originality/value – Service quality research has been conducted, almost exclusively, in first-class (4-star) and luxury (5-star) hotels, while the majority of hotels do not fall into these categories. Although guest expectations relative to service quality may be lower in more moderately priced, mid-scale hotels, service quality remains a critical variable that influences a guest’s decision to return or recommend a hotel to others. Many travelers now utilize online reviews to minimize purchase risk by seeking information relative to service quality when selecting a hotel. Consequently, it is more important than ever that service quality is understood in hotels at all service levels. The present research contributes to filling this gap in the literature.

Health harm of work from the sustainable HRM perspective: scale development and validation

2016 ◽  
Vol 37 (6) ◽  
pp. 924-944 ◽  
Author(s):  
Sugumar Mariappanadar
Keyword(s):  
Psychological Health ◽  
Discriminant Validity ◽  
Three Dimensional ◽  
Well Being ◽  
Three Dimensions ◽  
Three Dimensional Model ◽  
Positive Health ◽  
Study Item ◽  
Confirmatory Factor Analyses ◽  
Content Type

Purpose The purpose of this paper is to develop a health harm of work scale from the sustainable HRM perspective. Design/methodology/approach A three-dimensional model was proposed for the health harm of work scale and validated (Total n=527) using a five-part study (item generation, item reduction, convergent, construct and discriminant validity). Findings Exploratory and confirmatory factor analyses supported that the three dimensions (restrictions for positive health, the risk factors for psychological health and the side effect harm of work) simultaneously tap into different aspects of the health harm of work construct. The results from the construct validity revealed that health harm of work as a phenomenon has manifested itself in different facets of health harm of work intensification. Finally, the discriminant validity study revealed that the overlap between the dimensions of the health harm of work scale and the dimensions of recovery experience from the work questionnaire is low and it provides support for the discriminant validity of dimensions between these two scales. Practical implications The proposed measure can be used as potential leading indicators for negative occupational health to prevent or delay the onset of work-related illness manifestation or health consequences (sick leave, absenteeism, presenteeism, etc.). Originality/value This is the first study to validate a measure of health harm of work and to provide tangible evidence of health harm of work which will subsequently trigger organizations to introduce a planned intervention to improve occupational well-being to promote sustainable HRM.

scholarly journals A flash-based thermal simulation of scanning paths in LPBF additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kamel Ettaieb ◽  
Sylvain Lavernhe ◽  
Christophe Tournier
Keyword(s):  
High Performance ◽  
Laser Scanning ◽  
Thermal Field ◽  
Computational Cost ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Content Type ◽  
Proposed Model ◽  
Scanning Path

Purpose This paper aims to propose an analytical thermal three-dimensional model that allows an efficient evaluation of the thermal effect of the laser-scanning path. During manufacturing by laser powder bed fusion (LPBF), the laser-scanning path influences the thermo-mechanical behavior of parts. Therefore, it is necessary to validate the path generation considering the thermal behavior induced by this process to improve the quality of parts. Design/methodology/approach The proposed model, based on the effect of successive thermal flashes along the scanning path, is calibrated and validated by comparison with thermal results obtained by FEM software and experimental measurements. A numerical investigation is performed to compare different scanning path strategies on the Ti6Al4V material with different stimulation parameters. Findings The simulation results confirm the effectiveness of the approach to simulate the thermal field to validate the scanning strategy. It suggests a change in the scale of simulation thanks to high-performance computing resources. Originality/value The flash-based approach is designed to ensure the quality of the simulated thermal field while minimizing the computational cost.

scholarly journals Low-Avidity Autoantibodies against Bactericidal/Permeability-Increasing Protein Occur in Gram-Negative and Gram-Positive Bacteremia

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
J. Theprungsirikul ◽  
J. T. Thaden ◽  
R. M. Wierzbicki ◽  
A. S. Burns ◽  
S. Skopelja-Gardner ◽  
...  
Keyword(s):  
Blood Cultures ◽  
Chronic Obstructive ◽  
High Avidity ◽  
Igg Antibody ◽  
Gram Positive ◽  
Obstructive Pulmonary Disease ◽  
Gram Negative ◽  
Content Type ◽  
Chronic Respiratory Infection ◽  
Bacteremic Patient

ABSTRACT Antibody autoreactivity against bactericidal/permeability-increasing protein (BPI) is strongly associated with Pseudomonas aeruginosa infection in cystic fibrosis (CF), non-CF bronchiectasis (BE), and chronic obstructive pulmonary disease (COPD). We examined the pathogen-specific nature of this autoreactivity by examining antibodies to BPI in bacteremia patients. Antibodies to BPI and bacterial antigens were measured in sera by ELISA from five patient cohorts (n = 214). Antibody avidity was investigated. Bacteremic patient sera (n = 32) exhibited IgG antibody autoreactivity against BPI in 64.7% and 46.7% of patients with positive blood cultures for P. aeruginosa and Escherichia coli, respectively. Autoantibody titers correlated with IgG responses to bacterial extracts and lipopolysaccharide (LPS). A prospective cohort of bacteremic patient sera exhibited anti-BPI IgG responses in 23/154 (14.9%) patients with autoreactivity present at the time of positive blood cultures in patients with Gram-negative and Gram-positive bacteria, including 8/60 (13.3%) patients with Staphylococcus aureus. Chronic tissue infection with S. aureus was associated with BPI antibody autoreactivity in 2/15 patients (13.3%). Previously, we demonstrated that BPI autoreactivity in CF patient sera exhibits high avidity. Here, a similar pattern was seen in BE patient sera. In contrast, sera from patients with bacteremia exhibited low avidity. These data indicate that low-avidity IgG responses to BPI can arise acutely in response to bacteremia and that this association is not limited to P. aeruginosa. This is to be contrasted with chronic respiratory infection with P. aeruginosa, suggesting that either the chronicity or the site of infection selects for the generation of high-avidity responses, with biologic consequences for airway immunity.

Stakeholder power and corporate social performance

2014 ◽  
Vol 14 (3) ◽  
pp. 363-381 ◽  
Author(s):  
Béchir Ben Lahouel ◽  
Jean-Marie Peretti ◽  
David Autissier
Keyword(s):  
Stakeholder Theory ◽  
Corporate Social Performance ◽  
Social Performance ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Content Type ◽  
Strategic Posture ◽  
Corporate Social ◽  
The Relationship

Purpose – This paper aims to explore the power of one of the primary organizational stakeholders (shareholders) in the development of a corporate social performance (CSP) score. Few research works in the CSP empirical literature have studied the relationship between stakeholder power and CSP. Design/methodology/approach – Stakeholder theory is used as a theoretical framework to explain how shareholder voting power can influence the CSP level of French publicly listed companies. Stakeholder theory is tested through the operationalization of Ullmann’s (1985) three-dimensional model. Hypotheses related to shareholder voting power, strategic posture and financial performance are formulated through a literature review. A Data Envelopment Analysis approach was presented as a strong tool to measure CSP level. Multiple linear regressions were undertaken to test the hypotheses in a sample of 129 French companies between 2006 and 2007. Findings – The results indicate that companies with dispersed ownership and high proportion of institutional shareholders record a high score of CSP. Strategic posture measured by the implementation of environmental certification standard was positively and significantly related to CSP. Financial performance does not affect significantly the level of CSP. Originality/value – This paper is the first to empirically analyse the relationship between Ullmann’s three-dimensional model and CSP level in the French context. It offers to managers a better understanding of the power that certain stakeholders can use to acquire satisfaction.

Research of leakage magnetic field in deenergized transformer

2018 ◽  
Vol 37 (5) ◽  
pp. 1657-1667
Author(s):  
Jacek Horiszny
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Power Transformer ◽  
Three Dimensional ◽  
Magnetic Sensors ◽  
Three Dimensional Model ◽  
Content Type ◽  
The Core ◽  
Leakage Field ◽  
The Magnetic Field

Purpose The paper presents the analysis of magnetic field that surrounds the power transformer after it has been switched off. The purpose of this paper is to determine the possibility of defining the residual fluxes in the legs of the transformer based on the measurement of this field. It was also intended to determine the type and the location of magnetic sensors. Design/methodology/approach Numerical analysis of the magnetic field was performed. A three-dimensional model of the transformer’s magnetic core was created in the Flux 3D simulation program. The analysis was concerned with an oil-filled transformer and a dry transformer. The magnetic field of Earth was taken into account. Findings The research has shown that magnetic induction of the leakage field produced by residual magnetization of the core is comparable to the magnetic induction of the Earth’s field. It was also found that the measurement of the magnetic induction should be performed as close as possible to the core. The interior of the tank turned out to be a convenient space for the placement of the sensors. Research limitations/implications The influence of external ferromagnetic objects, and devices generating magnetic field, on the measurement was not considered. It should be taken into account in the future work. Originality/value On the basis of the analysis, it was proposed to measure the magnetic induction vector of the leakage field at three points. The sensors should be placed in front of the columns at a position that is half of their height. The measurement can be performed with satisfactory accuracy by sensors located on the surface of the windings.

Thermomechanical stress analysis for gas turbine blade with cooling structures

2018 ◽  
Vol 14 (4) ◽  
pp. 722-734 ◽  
Author(s):  
Fujuan Tong ◽  
Wenxuan Gou ◽  
Lei Li ◽  
Wenjing Gao ◽  
Zhu Feng Yue
Keyword(s):  
Stress Analysis ◽  
Gas Turbine ◽  
Radial Displacement ◽  
Three Dimensional ◽  
Mechanical Effect ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Three Dimensional Model ◽  
Content Type ◽  
Thermomechanical Effect

Purpose Blade tip clearance has always been a concern for the gas turbine design and control. The numerical analysis of tip clearance is based on the turbine components displacement. The purpose of this paper is to investigate the thermal and mechanical effects on a real cooling blade rather than the simplified model. Design/methodology/approach The coupled fluid-solid method is used. The thermal analysis involves solid and fluid domains. The distributions of blade temperature, stress and displacement have been calculated numerically under real turbine operating conditions. Findings Temperature contour can provide a reference for stress analysis. The results show that temperature gradient is the main source of solid stress and radial displacement. Compared with thermal or mechanical effect, there is a great change of stress magnitude for the thermomechanical effect. Large stress gradients are found between the leading and trailing edge of turbine cooling blade. Also, the blade radial displacement is mainly attributed to the thermal load rather than the centrifugal force. The analysis of the practical three-dimensional model has achieved the more precise results. Originality/value It is significant for clearance design and life prediction.

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