bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Helicobacter pylori HP0231 (DsbK): role in disulfide bond formation, redox homeostasis and production of Helicobacter cystein‐rich protein HcpE
Authors: Lester Jeffrey , Kichler Sari , Oickle Brandon , Fairweather Spencer , Oberc Alexander , Chahal Jaspreet , Ratnayake Dinath , Creuzenet Carole 
Published: January 2015

SummaryHelicobacter pylori is a human gastric pathogen that colonizes ∼ 50% of the world's population. It can cause gastritis, gastric or duodenal ulcers and also gastric cancer. The numerous side effects of available treatments and the emergence of antibiotic resistant strains are severe concerns that justify further research into H. pylori's pathogenic mechanisms. H. pylori produces secreted proteins that may play a role in virulence, including the Helicobacter cysteine‐rich protein HcpE (aka HP0235). We demonstrate herein that HcpE is secreted in the culture supernatant both as a soluble protein and in association with outer membrane vesicles. We show that the structure of HcpE comprises an organized array of disulfide bonds. We identify DsbK (aka HP0231) as a folding factor necessary for HcpE production and secretion in H. pylori and show that recombinant DsbK can interact with and refold unprocessed, reduced HcpE in vitro. These experiments highlight the first biologically relevant substrate for DsbK. Furthermore, we show that DsbK has disulfide bond (Dsb) forming activity on reduced lysozyme and demonstrate a DsbA‐type of activity for DsbK upon expression in E. coli, despite its similarity with DsbG. Finally, we show a role of DsbK in maintaining redox homeostasis in H. pylori.
Proximity and Scientific Collaboration: Evidence from the Global Wine Industry
Authors: Cassi Lorenzo , Morrison Andrea , Rabellotti Roberta 
Published: January 2015

AbstractInternational collaboration among researchers is a far from linear and straightforward process. Scientometric studies provide a good way of understanding why and how international research collaboration occurs and what are its costs and benefits. Our study investigates patterns of international scientific collaboration in a specific field: wine related research. We test a gravity model that accounts for geographical, cultural, commercial, technological, structural and institutional differences among a group of old world (OW) and new world (NW) producers and consumers. Our findings confirm the problems imposed by geographical and technological distance on international research collaboration. Furthermore, they show that similarity in trade patterns has a positive impact on international scientific collaboration. We also find that international research collaboration is more likely among peers; in other words, among wine producing countries that belong to the same group, for example, OW producers or newcomers to the wine industry,
A Race Motorcycle Frame: Advanced Design
Authors: Ballo Federico , Gobbi Massimiliano , Massera Marta , Mastinu Giampiero 
Published: January 2015

The concept and the embodiment design of a frame for a race motorcycle is addressed. The motorcycle is designed for the Moto3 World Championship. The aim is to develop a frame that could be eventually produced by die casting.
Given the basic geometry of the motorcycle and the engine dimensions, a multi-body model is derived by Modelica. The model is able to simulate the dynamic behaviour of the motorcycle in the two most critical conditions of use, namely braking and passing over a cleat. A comparison with experimental data has allowed the validation of the model.
By means of Optistruct, an optimized structure for the frame is proposed and compared to the one derived by an experienced designer. A technique is proposed for the computation of stresses in the frame that exploits, in an integrated manner, FEM and multi-body modeling. A fatigue analysis aimed at assessing the life of the frame is performed.
The combination of the most advanced modeling tools has enabled the design of a very light and stiff frame, additionally a process has been derived for future development of optimised motorcycle frames.
Hands-On Online? An Investigation of Experiential Design Education With Online Resources
Authors: Ramos Joshua D. , Wallace David R. 
Published: January 2015

Online education is becoming more prevalent in every field, especially with the advent of MOOCs and initiatives such as Coursera, Edx, MITx, Khan Academy and more. Product design education involves open-ended problem solving and prototyping with physical materials, so it presents a number of interesting challenges in an online educational setting.
This paper describes an initial study to better understand the value proposition of offering hands-on product design education using different delivery methods, ranging from hands-on residential to fully online, and combinations in-between. A series of two-day workshops were used to teach students typical introductory product design coursework including opportunity identification and early-stage prototyping. Students attended one workshop session that was taught with one of three content delivery types: traditional (n = 9), online (n = 9), or hybrid (n = 8). Each student worked individually to identify a product opportunity and produce a preliminary prototype. The performance of the students was compared to elucidate any differences based on workshop delivery method.
Based on the comparison of student work, as evaluated by academic product design experts, there were no statistically significant differences in performance between groups. This result suggests that all delivery methods have potential for successfully transferring knowledge to students. Furthermore, this preliminary evidence warrants more detailed investigations of the effects of delivery method on product design education. Interesting observations regarding workshop attendance identify motivation to complete courses as a point of interest in both residential and online settings. A number of insights gained and possible directions are discussed.
An Omnidirectional, Direct Singularity Drive System and its Inverse Kinematic Model
Authors: Reyer Julie A. , West Matthew T. , Jonnavittula Praveen K. , Costello Christopher T. , Boirum Curtis 
Published: January 2015

This paper presents an omnidirectional drive system. The design presented here involves a spinning hemispherical wheel mounted on a gimbal. The wheel operates at its singularity point when in the “neutral” or static position. As the gimbal is tilted, the wheel provides a thrust vector to the vehicle. The tilt determines the effective radius of the wheel, which in turn determines the amount of power that can be transmitted for motion. The paper presents the design and kinematic and inverse kinematics analysis of a singularity drive mechanism.
Vehicles can have single or multiple singularity drive mechanisms to achieve increasing levels of maneuverability. From a control standpoint, each singularity drive is kinematically decoupled from other drives on the same vehicle. Vehicles with one, two and three singularity drive mechanisms are introduced and some experimental results are presented.
Analysis of Rollover Shape and Energy Storage and Return in Cantilever Beam-Type Prosthetic Feet
Authors: Olesnavage Kathryn M. , Winter Amos G. 
Published: January 2015

This paper presents an analysis of the rollover shape and energy storage and return in a prosthetic foot made from a compliant cantilevered beam. The rollover shape of a prosthetic foot is defined as the path of the center of pressure along the bottom of the foot during stance phase of gait, from heel strike to toe off. This path is rotated into the reference frame of the ankle-knee segment of the leg, which is held fixed. In order to achieve correct limb loading and gait kinematics, it is important that a prosthetic foot both mimic the physiological rollover shape and maximize energy storage and return.
The majority of prosthetic feet available on the market are cantilever beam-type feet that emulate ankle dorsiflexion through beam bending. In this study, we show analytically that a prosthetic foot consisting of a beam with constant or monotonically decreasing cross-section cannot replicate physiological rollover shape; the foot is either too stiff when the ground reaction force (GRF) acts near the ankle, or too compliant when the GRF acts near the toe. A rigid constraint is required to prevent the foot from over-deflecting.
Using finite element analysis (FEA), we investigated how closely a cantilever beam with constrained maximum deflection could mimic physiological rollover shape and energy storage/return during stance phase. A constrained beam with constant cross-section is able to replicate physiological rollover shape with R2 = 0.86. The ratio of the strain energy stored and returned by the beam compared to the ideal energy storage and return is 0.504. This paper determines that there is a trade off between rollover shape and energy storage and return in cantilever beam-type prosthetic feet. The method and results presented in this paper demonstrate a useful tool in early stage prosthetic foot design that can be used to predict the rollover shape and energy storage of any type of prosthetic foot.
Innovative Tool for Specifying Customer Requirements
Authors: Ellman Asko , Wendrich Robert , Tiainen Tarja 
Published: January 2015

This paper presents the design and development of an App based tool for specification of customer requirements (CR) for product development. The most Quality Function Deployment (QFD) tools and methods are system based or used as an Excel document for specification and evaluation. Nowadays tool usage, functionality, and interaction can be designed simple, effective and aesthetically pleasing by means of native apps. They can be opened and accessed directly, much quicker, are rewarding, and enhance the user experience, even offline. Furthermore, the dynamic and playful use of an app will stimulate the interaction, motivation, and communication across various information platforms.
We describe and show the initial testing and experiments with the Customer Priorities (CP) App and present preliminary findings and results from our ongoing research. This in turn leads and enables designers and engineers to move closer to the future users, understand their wishes, values and choices between passive and active needs. QFD defines mapping between customer requirements and product characteristics. In practice this means that a customer compares two product characteristics at time and defines which one is more important or if they are equally important.
The App was tested in a user experiment. We considered a Smartphone as a design example. We asked test users to compare and specify their preferences for ten given product characteristics. Our test user group consists of 32 participants both from Finland and the Netherlands. They were either graduated students or teaching staff from a university. We show preliminary results and findings from user experiment and testing of the App. Furthermore qualitative results achieved in interview with test users will be presented.
5-Lipoxygenase Negatively Regulates Th1 Response during Brucella abortus Infection in Mice
Authors: Fahel Júlia Silveira , de Souza Mariana Bueno , Gomes Marco Túlio Ribeiro , Corsetti Patricia P. , Carvalho Natalia B. , Marinho Fabio A. V. , de Almeida Leonardo A. , Caliari Marcelo V. , Machado Fabiana Simão , Oliveira Sergio Costa 
Published: January 2015

ABSTRACT

Brucella abortus
is a Gram-negative bacterium that infects humans and cattle, causing a chronic inflammatory disease known as brucellosis. A Th1-mediated immune response plays a critical role in host control of this pathogen. Recent findings indicate contrasting roles for lipid mediators in host responses against infections. 5-Lipoxygenase (5-LO) is an enzyme required for the production of the lipid mediators leukotrienes and lipoxins. To determine the involvement of 5-LO in host responses to
B. abortus
infection, we intraperitoneally infected wild-type and 5-LO-deficient mice and evaluated the progression of infection and concomitant expression of immune mediators. Here, we demonstrate that
B. abortus
induced the upregulation of 5-LO mRNA in wild-type mice. Moreover, this pathogen upregulated the production of the lipid mediators leukotriene B
4
and lipoxin A
4
in a 5-LO-dependent manner. 5-LO-deficient mice displayed lower bacterial burdens in the spleen and liver and less severe liver pathology, demonstrating an enhanced resistance to infection. Host resistance paralleled an increased expression of the proinflammatory mediators interleukin-12 (IL-12), gamma interferon (IFN-γ), and inducible nitric oxide synthase (iNOS) during the course of infection. Moreover, we demonstrated that 5-LO downregulated the expression of IL-12 in macrophages during
B. abortus
infection. Our results suggest that 5-LO has a major involvement in
B. abortus
infection, by functioning as a negative regulator of the protective Th1 immune responses against this pathogen.
Photobacterium damselae subsp. damselae Major Virulence Factors Dly, Plasmid-Encoded HlyA, and Chromosome-Encoded HlyA Are Secreted via the Type II Secretion System
Authors: Rivas Amable J. , Vences Ana , Husmann Matthias , Lemos Manuel L. , Osorio Carlos R. 
Published: January 2015

ABSTRACT

Photobacterium damselae
subsp.
damselae
is a marine bacterium that causes septicemia in marine animals and in humans. Previously, we had determined a major role of pPHDD1 plasmid-encoded Dly (damselysin) and HlyA (HlyA
pl
) and the chromosome-encoded HlyA (HlyA
ch
) hemolysins in virulence. However, the mechanisms by which these toxins are secreted remain unknown. In this study, we found that a mini-Tn
10
transposon mutant in a plasmidless strain showing an impaired hemolytic phenotype contained an insertion in
epsL
, a component of a type II secretion system (T2SS). Reconstruction of the mutant by allelic exchange confirmed the specific involvement of
epsL
in HlyA
ch
secretion. In addition, mutation of
epsL
in a pPHDD1-harboring strain caused an almost complete abolition of hemolytic activity against sheep erythrocytes, indicating that
epsL
plays a major role in secretion of the plasmid-encoded HlyA
pl
and Dly. This was further demonstrated by analysis of different combinations of hemolysin gene mutants and by strain-strain complementation assays. We also found that mutation of the putative prepilin peptidase gene
pilD
severely affected hemolysis, which dropped at levels inferior to those of
epsL
mutants. Promoter expression analyses suggested that impairment of hemolysin secretion in
epsL
and
pilD
mutants might constitute a signal that affects hemolysin and T2SS gene expression at the transcriptional level. In addition, single
epsL
and
pilD
mutations caused a drastic decrease in virulence for mice, demonstrating a major role of T2SS and
pilD
in
P. damselae
subsp.
damselae
virulence.
Resistance of Neisseria meningitidis to Human Serum Depends on T and B Cell Stimulating Protein B
Authors: Müller Maike G. , Moe Nina E. , Richards Phillip Q. , Moe Gregory R. 
Published: January 2015

ABSTRACT

The ability of the human bacterial pathogen
Neisseria meningitidis
to cause invasive disease depends on survival in the bloodstream via mechanisms to suppress complement activation. In this study, we show that prophage genes coding for T and B cell stimulating protein B (TspB), which is an immunoglobulin-binding protein, are essential for survival of
N. meningitidis
group B strain H44/76 in normal human serum (NHS). H44/76 carries three genes coding for TspB. Mutants having all
tspB
genes inactivated did not survive in >5% NHS or IgG-depleted NHS. TspB appeared to inhibit IgM-mediated activation of the classical complement pathway, since survival of the
tspB
triple knockout was the same as that of the parent strain or a complemented mutant when the classical pathway was inactivated by depleting NHS of C1q and was increased in IgM-depleted NHS. A mutant solely carrying
tspB
gene
nmbh4476_0681
was as resistant as the parent strain, while mutants carrying only
nmbh4476_0598
or
nmbh4476_1698
were killed in ≥5% NHS. The phenotype associated with TspB is formation of a matrix containing TspB, IgG, and DNA that envelopes aggregates of bacteria. Recombinant proteins corresponding to particular subdomains of TspB were found to have human IgG Fcγ- and/or DNA-binding activity, but only TspB derivatives containing both domains formed large, biofilm-like aggregates when combined with purified IgG and DNA. Recognizing the role of TspB in serum resistance may lead to a better understanding of why strains that carry
tspB
genes are associated with invasive meningococcal disease.
Protocol for a multicentre, prospective, population-based cohort study of variation in practice of cholecystectomy and surgical outcomes (The CholeS study)
Authors: Vohra Ravinder S , Spreadborough Philip , Johnstone Marianne , Marriott Paul , Bhangu Aneel , Alderson Derek , Morton Dion G , Griffiths Ewen A 
Published: January 2015

IntroductionCholecystectomy is one of the most common general surgical operations performed. Despite level one evidence supporting the role of cholecystectomy in the management of specific gallbladder diseases, practice varies between surgeons and hospitals. It is unknown whether these variations account for the differences in surgical outcomes seen in population-level retrospective data sets. This study aims to investigate surgical outcomes following acute, elective and delayed cholecystectomies in a multicentre, contemporary, prospective, population-based cohort.Methods and analysisUK and Irish hospitals performing cholecystectomies will be recruited utilising trainee-led research collaboratives. Two months of consecutive, adult patient data will be included. The primary outcome measure of all-cause 30-day readmission rate will be used in this study. Thirty-day complication rates, bile leak rate, common bile duct injury, conversion to open surgery, duration of surgery and length of stay will be measured as secondary outcomes. Prospective data on over 8000 procedures is anticipated. Individual hospitals will be surveyed to determine local policies and service provision. Variations in outcomes will be investigated using regression modelling to adjust for confounders.Ethics and disseminationResearch ethics approval is not required for this study and has been confirmed by the online National Research Ethics Service (NRES) decision tool. This novel study will investigate how hospital-level surgical provision can affect patient outcomes, using a cross-sectional methodology. The results are essential to inform commissioning groups and implement changes within the National Health Service (NHS). Dissemination of the study protocol is primarily through the trainee-led research collaboratives and the Association of Upper Gastrointestinal Surgeons (AUGIS). Individual centres will have access to their own results and the collective results of the study will be published in peer-reviewed journals and presented at relevant surgical conferences.
Barriers to cervical cancer screening among ethnic minority women: a qualitative study
Authors: Marlow Laura A V , Waller Jo , Wardle Jane 
Published: January 2015

BackgroundEthnic minority women are less likely to attend cervical screening.AimTo explore self-perceived barriers to cervical screening attendance among ethnic minority women compared to white British women.DesignQualitative interview study.SettingCommunity groups in ethnically diverse London boroughs.MethodsInterviews were carried out with 43 women from a range of ethnic minority backgrounds (Indian, Pakistani, Bangladeshi, Caribbean, African, Black British, Black other, White other) and 11 White British women. Interviews were recorded, transcribed verbatim and analysed using Framework analysis.ResultsFifteen women had delayed screening/had never been screened. Ethnic minority women felt that there was a lack of awareness about cervical cancer in their community, and several did not recognise the terms ‘cervical screening’ or ‘smear test’. Barriers to cervical screening raised by all women were emotional (fear, embarrassment, shame), practical (lack of time) and cognitive (low perceived risk, absence of symptoms). Emotional barriers seemed to be more prominent among Asian women. Low perceived risk of cervical cancer was influenced by beliefs about having sex outside of marriage and some women felt a diagnosis of cervical cancer might be considered shameful. Negative experiences were well remembered by all women and could be a barrier to repeat attendance.ConclusionsEmotional barriers (fear, embarrassment and anticipated shame) and low perceived risk might contribute to explaining lower cervical screening coverage for some ethnic groups. Interventions to improve knowledge and understanding of cervical cancer are needed in ethnic minority communities, and investment in training for health professionals may improve experiences and encourage repeat attendance for all women.
Direct aspiration first pass technique for the treatment of acute ischemic stroke: initial experience at a European stroke center
Authors: Kowoll Annika , Weber Anushe , Mpotsaris Anastasios , Behme Daniel , Weber Werner 
Published: January 2015

IntroductionOver the past decade, endovascular techniques for the treatment of acute ischemic stroke have emerged significantly. However, revascularization rates are limited at approximately 80%, and mechanical thrombectomy procedures still last about 1 h. Therefore, we investigated the novel direct aspiration first pass technique for its efficacy and safety.MethodsOur neurointerventional database was screened for patients who received mechanical thrombectomy for acute ischemic stroke using the Penumbra 5MAX ACE aspiration catheter on an intention to treat basis between November 2013 and June 2014. Procedural data, including modified Thrombolysis in Cerebral Infarction (mTICI) score, procedural timings, and complications, as well as clinical data at admission and discharge, were analyzed.Results54 patients received mechanical thrombectomy using the 5MAX ACE. Median age was 69 (39–94) years (54% were men). Baseline National Institutes of Health Stroke Scale (NIHSS) score was 15 (2–27) and 44/54 (81%) patients received intravenous thrombolysis. Vessel occlusion sites were 91% anterior circulation and 9% posterior circulation. A successful revascularization result (mTICI ≥2b) was achieved in 93% of cases whereas direct aspiration alone was successful in 30/54 (56%) cases; among these, median time from groin puncture to revascularization was 30 min (9–113). Symptomatic intracranial hemorrhage occurred in 2/54 (4%) patients, and embolization to new territories in 3/54 (6%). Median NIHSS at discharge was 6 (0–24); 46% of patients were independent at discharge.ConclusionsThe direct aspiration first pass technique proofed to be fast, effective, and safe. Promising revascularization results can be achieved quickly in more than 50% of patients using this technique as the firstline option. Nevertheless, stent retrievers are still warranted in approximately 40% of cases to achieve a favorable revascularization result.