bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre-Strain Effects on Mixed-Mode Fatigue Crack Propagation Behaviour of the P355NL1 Pressure Vessels Steel
Authors: Ferreira João , A. F. O. Correia José , Lesiuk Grzegorz , Blasón González Sergio , R. Gonzalez Maria Cristina , de Jesus Abílio M. P. , Fernández-Canteli Alfonso
Published: October 2018

Pressure vessels and piping are commonly subjected to plastic deformation during manufacturing or installation. This pre-deformation history, usually called pre-strain, may have a significant influence on the resistance against fatigue crack growth of the material. Several studies have been performed to investigate the pre-strain effects on the pure mode I fatigue crack propagation, but less on mixed-mode (I+II) fatigue crack propagation conditions.

The present study aims at investigating the effect of tensile plastic pre-strain on fatigue crack growth behavior (da/dN vs. ΔK) of the P355NL1 pressure vessel steel. For that purpose, fatigue crack propagation tests were conducted on specimens with two distinct degrees of pre-strain: 0% and 6%, under mixed mode (I+II) conditions using CTS specimens. Moreover, for comparison purposes, CT specimens were tested under pure mode I conditions for pre-strains of 0% and 3%. Contrary to the majority of previous studies, that applied plastic deformation directly on the machined specimen, in this work the pre-straining operation was carried out prior to the machining of the specimens with the objective to minimize residual stress effects and distortions. Results revealed that, for the P355NL1 steel, the tensile pre-strain increased fatigue crack initiation angle and reduced fatigue crack growth rates in the Paris region for mixed mode conditions. The pre-straining procedure had a clear impact on the Paris law constants, increasing the coefficient and decreasing the exponent. In the low ΔK region, results indicate that pre-strain causes a decrease in ΔKth.
Investigation of Calculating Stress Intensity Factor at Surface Point and its Inclusion in Engineering Standards
Authors: Xu Steven X. , Thorwald Greg , Le Delliou Patrick , Cipolla Russell C.
Published: October 2018

Article A-3000 of Appendix A in ASME Section XI provides methods to calculate stress intensity factors that are used in Section XI linear elastic fracture mechanics based flaw evaluation procedures. The ASME Section XI Working Group on Flaw Evaluation has been in the process of rewriting Article A-3000 of Appendix A. The rewrite of Article A-3000 includes implementation of closed-form equations for stress intensity factor influence coefficients for cylinder geometries.

Closed-form relations for stress influence coefficients G0 and G1 for axial flaws on the outside surface in cylinders were recently developed and implemented into the 2017 Edition of ASME Section XI Appendix A. The closed-form equations were implemented with one restriction on the application related to very long flaws. This restriction was taken as an interim approach to addressing a technical concern from the US NRC staff. NRC staff had technical concern on the large percentage fitting errors for the G1 influence coefficients at surface point for some very long flaws. An action was assigned within the ASME Section XI Working Group on Flaw Evaluation to investigate the accuracy of surface point G values for very long flaws. The intent of the investigation is to provide technical justification for using the closed-form equations with no restriction and to identify any issues in the source data or during the fitting process. This paper describes current results from this ongoing investigation.
Friction Factor Between Gasket and Flange Surface
Authors: Schaaf Manfred , Zeuss Rainer
Published: October 2018

In December 2013, a new version of EN 1591-1 (1) was issued. Apart from several other modifications, the treatment of external loads was included in this calculation standard for circular bolted flanged joints. In the former standard, only axial forces and bending moments resulting from the piping system were considered; in the new issue lateral forces and shear moments can also be treated.

There are two possibilities to counterbalance the lateral forces and the shear moments: firstly by metallic contact of the flanges and secondly by friction between the gasket and the flange surfaces. While the first option cannot occur in the type of flange connection (with a floating gasket between the flanges) covered by EN 1591-1, the lateral displacement of the flanges can only be prevented by friction between the gasket and flange surfaces. Therefore, the friction factor μG was introduced in the calculation procedure.

In an informative annex of EN 1591-1 (Annex E), some friction factors are published exemplarily. These factors are based on values published in the German nuclear codes KTA 3201.2 (2) and KTA 3211.2 (3). The origin of these values can’t be retraced anymore. For this reason, it is stated in Annex E that these values are probably very conservative, and that an experimental determination of the factors should be preferentially used. Incidentally, overly conservative friction factors lead to higher required bolt forces to counterbalance the external loads, which may result in an overstressing of the components of the bolted flanged joint.

Therefore, the European Sealing Association (ESA) decided to determine generic data for different types of gaskets which could be published in the next revision of EN 1591-1. In this paper the results of this project are presented.
Development of Improved Equations for Weld Heat Input and Dilution Control: Part 2
Authors: Tatman Jonathan K.
Published: October 2018

This report introduces techniques involving novel calculation methods developed by the Electric Power Research Institute and Bechtel Marine Propulsion Corporation [1] that can be used to develop an improved understanding of welding factors affecting substrate weld heat input and dilution. These improved calculation methods are especially warranted in ASME BPVC Section XI repair and replacement welding activities such as mitigation of hot cracking (dilution control) and optimization of temper bead welding (heat input control). Various parameter sets are tested to demonstrate the effectiveness of the new calculation methods and how they can be refined in future studies to further improve accuracy. Additionally, this report highlights the limitations associated with the ASME BPVC Section IX theoretical heat input and power ratio calculation methods widely used in the welding industry for control of substrate heat input and weld dilution. Weld trials are performed in this study to demonstrate the limitations and determine proper precautions to take when using the calculation methods.
Effects of Strain Rate and Temperature on Ductile Damage of Metals
Authors: Sancho Alexander , Cox Mike J. , Cartwright Tim , Hooper Paul A. , Dear John P. , Davies Catrin M.
Published: October 2018

Ductile damage appears in ductile metallic materials when these undergo sufficient plastic deformation, and it is caused by voids and microcracks that are formed within the material due to those severe conditions. The main interest of the present research is to experimentally characterise ductile damage in different conditions of strain rate (from quasi-static to 103s−1) and temperature (from −80°C to 180°C). Estimations of damage accumulation along the plastic regime have been taken by measuring the stiffness reduction of the material. The effects of strain localisation and necking have been accounted for by monitoring the changes in the geometry of the specimens during the test. At high speed these experiments have required the use of an in-situ shadowgraph method to monitor the sample silhouette and accurately calculate stress-strain behaviour throughout the test. The design of a novel experimental rig to perform high speed interrupted tensile tests has also been needed, in order to measure the damage accumulation in those conditions. The low and high temperature tests have been carried out inside an environmental chamber maintaining the rest of the technique unchanged. These experiments at varying strain rate and temperature have allowed to better understand the effect these conditions have on damage properties.
Fracture Mechanics Fatigue Evaluation of a Flowline Clamp Connector Using Finite Element Modeling of a Crack
Authors: Sifford Curtis , Shirani Ali
Published: October 2018

This paper presents the application of the rules from ASME Section VIII, Division 3 of the ASME Boiler and Pressure Vessel Code for a fracture mechanics evaluation to determine the damage tolerance and fatigue life of a flowline clamp connector. The guidelines from API 579-1 / ASME FFS-1 Fitness-For-Service for the stress analysis of a crack-like flaw have been considered for this assessment. The crack tip is modeled using a refined mesh around the crack tip that is referred to as a focused mesh approach in API 579-1 / ASME FFS-1. The driving force method is used as an alternative to the failure assessment diagram method to account for the influence of crack tip plasticity. The J integral is determined using elastic-plastic finite element analysis and converted to an equivalent stress intensity factor to be compared to the fracture toughness of the material. The fatigue life is calculated using the Paris Law equation and the stress intensity factor calculated from the finite element analysis. The allowable number of design cycles is determined using the safety factors required from Division 3 of the ASME Pressure Vessel Code.
FAST Club: The Impact of a Physical Activity Intervention on Executive Function in Children With Fetal Alcohol Spectrum Disorder
Authors: Pritchard Orr Alison B. , Keiver Kathy , Bertram Chris P. , Clarren Sterling
Published: October 2018

Physical activity (PA) has been demonstrated to have positive effects on cognitive function, particularly executive function (EF) skills. Animal models suggest PA may be effective in ameliorating some of the neuropsychological effects of fetal alcohol spectrum disorder (FASD), but this approach has not been extended to humans. The purpose of this study was to develop a PA program, FAST Club, for children with FASD and to evaluate its effect on a measure of EF. Using a wait-list control design, 30 children age 7–14 yr participated in FAST Club for 2 × 1.5-hr sessions/week for 8 weeks. EF was assessed using the Children’s Color Trails Test. Significant improvements in T scores on the Children’s Color Trails Test were seen immediately postprogram, and this improvement was sustained at 3 months postprogram. These findings provide evidence to support the use of PA as a means to improve EF in children with FASD.
Population Pharmacokinetic Model and Limited Sampling Strategies for Personalized Dosing of Levofloxacin in Tuberculosis Patients
Authors: van den Elsen Simone H. J. , Sturkenboom Marieke G. G. , van't Boveneind-Vrubleuskaya Natasha , Skrahina Alena , van der Werf Tjip S. , Heysell Scott K. , Mpagama Stellah , Migliori Giovanni B. , Peloquin Charles A. , Touw Daan J. , Alffenaar Jan-Willem C.
Published: October 2018

Levofloxacin is an antituberculosis drug with substantial interindividual pharmacokinetic variability; therapeutic drug monitoring (TDM) could therefore be helpful to improve treatment results. TDM would be more feasible with limited sampling strategies (LSSs), a method to estimate the area under the concentration curve for the 24-h dosing interval (AUC
0–24
) by using a limited number of samples.
Azidothymidine Produces Synergistic Activity in Combination with Colistin against Antibiotic-Resistant
Enterobacteriaceae
Authors: Hu Yanmin , Liu Yingjun , Coates Anthony
Published: October 2018

Bacterial infections remain a leading killer worldwide, which is worsened by the continuous emergence of antibiotic resistance. In particular, antibiotic-resistant
Enterobacteriaceae
are prevalent and extremely difficult to treat.
Inhibition of Cytomegalovirus Replication with Extended-Half-Life Synthetic Ozonides
Authors: Wang Yiping , Mukhopadhyay Rupkatha , Roy Sujayita , Kapoor Arun , Su Yu-Pin , Charman Susan A. , Chen Gong , Wu Jianbo , Wang Xiaofang , Vennerstrom Jonathan L. , Arav-Boger Ravit
Published: October 2018

Artesunate (AS), a semisynthetic artemisinin approved for malaria therapy, inhibits human cytomegalovirus (HCMV) replication
in vitro
, but therapeutic success in humans has been variable. We hypothesized that the short
in vivo
half-life of AS may contribute to the different treatment outcomes.
Chest pain following permanent pacemaker insertion… a case of pneumopericardium due to atrial lead perforation
Authors: Aktaa Suleman , Fatania Kavi , Gains Claire , White Hazel
Published: October 2018

Permanent pacemaker (PPM) implantation is an increasingly common procedure with complication rate estimated between 3% and 6%. Cardiac perforation by pacemaker lead(s) is rare, but a previous study has shown that it is probably an underdiagnosed complication. We are presenting a case of a patient who presented 5 days after PPM insertion with new-onset pleuritic chest pain. She had a normal chest X-ray (CXR), and acceptable pacing checks. However, a CT scan of the chest showed pneumopericardium and pneumothorax secondary to atrial lead perforation. The pain only settled by replacing the atrial lead. A repeat chest CT scan a few months later showed complete resolution of the pneumopericardium and pneumothorax. We believe that cardiac perforation can be easily missed if associated with normal CXR and acceptable pacing parameters. Unexplained chest pain following PPM insertion might be the only clue for such complication, although it might not always be present.
Adult bilateral idiopathic occlusion of foramina of Monro: is foraminoplasty really safe and effective?
Authors: Migliorati Karol , Muratori Andrea , Fontanella Marco Maria , Panciani Pier Paolo
Published: October 2018

Idiopathic bilateral occlusion of foramina of Monro is an extremely rare condition in adults and only few cases are reported. Currently, foraminoplasty is indicated as first-line treatment. We reported the case of a 52-year-old woman who presented with headache, instability and urinary incontinence. The imaging demonstrated bilateral occlusion of foramina of Monro and consequent biventricular hydrocephalus. A ventriculo-peritoneal shunt allowed to treat the hydrocephalus, but it was necessary to remove it for the appearance of peritonitis from salpingitis. Since the initial symptomatology reappeared, according to the literature, we performed an endoscopic foraminoplasty with septostomy. The patient immediately developed short-term memory impairment and subsequently we observed the hydrocephalus recurrence. The positioning of a ventriculo-atrial shunt allowed to improve the symptoms, but the memory remained impaired. In case of bilateral true stenosis of foramina of Monro, foraminoplasty may lead to severe memory impairment. Therefore, cerebrospinal fluid shunting should be considered as an effective and safer treatment.
Tuberous sclerosis complex: a clinical case with multiple ophthalmological manifestations
Authors: Maio Tiago , Lemos José , Moreira Jorge , Sampaio Filipa
Published: October 2018

The tuberous sclerosis complex is a rare disease, with autosomal dominant transmission, with multisystemic involvement including ophthalmologic. Retinal hamartomas and retinal achromic patch are the most frequent ocular findings. Other ophthalmic signs and symptoms are relatively rare in this disease.

We describe the case of a young woman with tuberous sclerosis who presented with horizontal binocular diplopia and decreased visual acuity without complaints of nausea, vomiting or headache. She had right abducens nerve palsy, pale oedema of both optic discs and retinal hamartomas. An obstructive hydrocephalus caused by an intraventricular expansive lesion was identified in brain CT.

Observation by the ophthalmologist is indicated in all confirmed or suspected cases of tuberous sclerosis to aid in clinical diagnosis, monitoring of retinal hamartomas or identification of poorly symptomatic papilloedema.
Crossing borders: the PACK experience of spreading a complex health system intervention across low-income and middle-income countries
Authors: Cornick Ruth , Wattrus Camilla , Eastman Tracy , Ras Christy Joy , Awotiwon Ajibola , Anderson Lauren , Bateman Eric , Zepeda Jorge , Zwarenstein Merrick , Doherty Tanya , Fairall Lara
Published: October 2018

Developing a health system intervention that helps to improve primary care in a low-income and middle-income country (LMIC) is a considerable challenge; finding ways to spread that intervention to other LMICs is another. The Practical Approach to Care Kit (PACK) programme is a complex health system intervention that has been developed and adopted as policy in South Africa to improve and standardise primary care delivery. We have successfully spread PACK to several other LMICs, including Botswana, Brazil, Nigeria and Ethiopia. This paper describes our experiences of localising and implementing PACK in these countries, and our evolving mentorship model of localisation that entails our unit providing mentorship support to an in-country team to ensure that the programme is tailored to local resource constraints, burden of disease and on-the-ground realities. The iterative nature of the model’s development meant that with each country experience, we could refine both the mentorship package and the programme itself with lessons from one country applied to the next—a ‘learning health system’ with global reach. While not yet formally evaluated, we appear to have created a feasible model for taking our health system intervention across more borders.
A qualitative exploration of information-seeking by electronic nicotine delivery systems (ENDS) users in New Zealand
Authors: Robertson Lindsay , Hoek Janet , Blank Mei-Ling , Richards Rosalina , Ling Pamela , Popova Lucy , McMillan Lydia
Published: October 2018

Objectives

Given recent increases in awareness and uptake of electronic nicotine delivery systems (ENDS), we aimed to explore ENDS users’ information needs and search behaviours and whether information gaps exist.

Design

Qualitative study using semistructured interviews that probed participants’ smoking behaviours and ENDS use; data in this study examine ENDS information-seeking behaviours. We used qualitative description to analyse interview transcripts.

Participants and setting

We recruited 39 current ENDS users (20 dual users and 19 exclusive ENDS users who reported having previously smoked cigarettes regularly) aged 18 and over, from three urban centres in New Zealand.

Results

Several participants used Google to search for information on ENDS’ health effects, but described the material they retrieved as vague or contradictory. Some interpreted the absence of information on long-term health effects as evidence ENDS did not pose potential health risks, and several perceived e-liquids as benign. Many relied on information sourced from other ENDS users, gleaned from online forums, YouTube or from discussions with friends and acquaintances; these sources typically presented ENDS positively. Several participants found specialist ENDS retailers provided valuable advice; non-specialist store staff generally lacked detailed product knowledge and sometimes offered inaccurate information.

Conclusion

People seeking information on ENDS’ health effects are more likely to retrieve recommendations, product reviews and endorsements from online sources or through exchanges with other users, than they are to find scientific data. Health authorities could help meet potential users’ information needs by, first, creating and frequently updating objective lay summaries of the latest scientific evidence; second, by mandating licensing for retailers with guidelines to disclose uncertainty over ENDS’ efficacy for cessation and longer-term health effects, and the need for complete substitution of ENDS for combustible cigarettes among those who use these products.
Funding and policy incentives to encourage implementation of point-of-care C-reactive protein testing for lower respiratory tract infection in NHS primary care: a mixed-methods evaluation
Authors: Johnson Matthew , Cross Liz , Sandison Nick , Stevenson Jamie , Monks Thomas , Moore Michael
Published: October 2018

Objectives

Utilisation of point-of-care C-reactive protein testing for lower respiratory tract infection has been limited in UK primary care, with costs and funding suggested as important barriers. We aimed to use existing National Health Service funding and policy mechanisms to alleviate these barriers and engage with clinicians and healthcare commissioners to encourage implementation.

Design

A mixed-methods study design was adopted, including a qualitative survey to identify clinicians’ and commissioners’ perceived benefits, barriers and enablers post-implementation, and quantitative analysis of results from a real-world implementation study.

Interventions

We developed a funding specification to underpin local reimbursement of general practices for test delivery based on an item of service payment. We also created training and administrative materials to facilitate implementation by reducing organisational burden. The implementation study provided intervention sites with a testing device and supplies, training and practical assistance.

Results

Despite engagement with several groups, implementation and uptake of our funding specification were limited. Survey respondents confirmed costs and funding as important barriers in addition to physical and operational constraints and cited training and the value of a local champion as enablers.

Conclusions

Although survey respondents highlighted the clinical benefits, funding remains a barrier to implementation in UK primary care and appears not to be alleviated by the existing financial incentives available to commissioners. The potential to meet incentive targets using lower cost methods, a lack of policy consistency or competing financial pressures and commissioning programmes may be important determinants of local priorities. An implementation champion could help to catalyse support and overcome operational barriers at the local level, but widespread implementation is likely to require national policy change. Successful implementation may reproduce antibiotic prescribing reductions observed in research studies.
Clinician perceptions of a prototype wearable exercise biofeedback system for orthopaedic rehabilitation: a qualitative exploration
Authors: Argent Rob , Slevin Patrick , Bevilacqua Antonio , Neligan Maurice , Daly Ailish , Caulfield Brian
Published: October 2018

Objectives

This study explores the opinions of orthopaedic healthcare professionals regarding the opportunities and challenges of using wearable technology in rehabilitation. It continues to assess the perceived impact of an exemplar exercise biofeedback system that incorporates wearable sensing, involving the clinician in the user-centred design process, a valuable step in ensuring ease of implementation, sustained engagement and clinical relevance.

Design

This is a qualitative study consisting of one-to-one semi-structured interviews, including a demonstration of a prototype wearable exercise biofeedback system. Interviews were audio-recorded and transcribed, with thematic analysis conducted of all transcripts.

Setting

The study was conducted in the orthopaedic department of an acute private hospital.

Participants

Ten clinicians from a multidisciplinary team of healthcare professionals involved in the orthopaedic rehabilitation pathway participated in the study.

Results

Participants reported that there is currently a challenge in gathering timely and objective data for the monitoring of patients in orthopaedic rehabilitation. While there are challenges in ensuring reliability and engagement of biofeedback systems, clinicians perceive significant value in the use of wearable biofeedback systems such as the exemplar demonstrated for use following total knee replacement.

Conclusions

Clinicians see an opportunity for wearable technology to continuously track data in real-time, and feel that feedback provided to users regarding exercise technique and adherence can further support the patient at home, although there are clear design and implementation challenges relating to ensuring technical accuracy and tailoring rehabilitation to the individual. There was perceived value in the prototype system demonstrated to participants which supports the ongoing development of such exercise biofeedback platforms.
Predictors of electrocardiographic QT interval prolongation in men with HIV
Authors: Wu Katherine C , Zhang Long , Haberlen Sabina A , Ashikaga Hiroshi , Brown Todd T , Budoff Matthew J , D’Souza Gypsyamber , Kingsley Lawrence A , Palella Frank J , Margolick Joseph B , Martínez-Maza Otoniel , Soliman Elsayed Z , Post Wendy S
Published: October 2018

Objective

HIV-infected (HIV+) individuals may be at increased risk for sudden arrhythmic cardiac death. Some studies have reported an association between HIV infection and prolongation of the electrocardiographic QT interval, a measure of ventricular repolarisation, which could potentiate ventricular arrhythmias. We aimed to assess whether HIV+ men have longer QT intervals than HIV-uninfected (HIV−) men and to determine factors associated with QT duration.

Methods

We performed resting 12-lead ECGs in 774 HIV+ and 652 HIV− men in the Multicenter AIDS Cohort Study (MACS). We used multivariable linear and logistic regression analyses to assess associations between HIV serostatus and Framingham corrected QT interval (QTc), after accounting for potential confounders. We also determined associations among QTc interval and HIV-related factors in HIV+ men. In a subgroup of participants, levels of serum markers of inflammation were also assessed.

Results

After adjusting for demographics and risk factors, QTc was 4.0 ms longer in HIV+ than HIV− men (p<0.001). Use of antiretroviral therapy (ART), specific ART drug class use and other HIV-specific risk factors were not associated with longer QTc. Among the subgroup with inflammatory biomarker measurements, higher interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1) and B-cell activating factor levels were independently associated with longer QTc and their inclusion partially attenuated the HIV effect.

Conclusions

HIV+ men had longer QTc, which was associated with higher levels of systemic inflammatory factors. This longer QTc may contribute to the increased risk for sudden arrhythmic cardiac death in some HIV+ individuals.
Novel methodology to discern predictors of remission and patterns of disease activity over time using rheumatoid arthritis clinical trials data
Authors:   RA-MAP Consortium
Published: October 2018

Objectives

To identify predictors of remission and disease activity patterns in patients with rheumatoid arthritis (RA) using individual participant data (IPD) from clinical trials.

Methods

Phase II and III clinical trials completed between 2002 and 2012 were identified by systematic literature review and contact with UK market authorisation holders. Anonymised baseline and follow-up IPD fromnon-biological armswere amalgamated. Multiple imputation was used to handle missing outcome and covariate information. Random effects logistic regression was used to identify predictors of remission, measured by the Disease Activity Score 28 (DAS28) at 6 months. Novel latent class mixed models characterised DAS28 over time.

Results

IPD of 3290 participants from 18 trials were included. Of these participants, 92% received methotrexate (MTX). Remission rates were estimated at 8.4%(95%CI 7.4%to9.5%) overall, 17%(95%CI 14.8%to19.4%) for MTX-naïve patients with early RA and 3.2% (95% CI 2.4% to 4.3%) for those with prior MTX exposure at entry. In prior MTX-exposed patients, lower baseline DAS28 and MTX reinitiation were associated with remission. In MTX-naïve patients, being young, white, male, with better functional and mental health, lower baseline DAS28 and receiving concomitant glucocorticoids were associated with remission. Three DAS28 trajectory subpopulations were identified in MTX-naïve and MTX-exposed patients. A number of variables were associated with subpopulation membership and DAS28 levels within subpopulations.

Conclusions 

Predictors of remission differed between MTX-naïve and prior MTX-exposed patients at entry. Latent class mixed models supported differential non-biological therapy response, with three distinct trajectories observed in both MTX-naïve and MTX-exposed patients. Findings should be useful when designing future RA trials and interpreting results of biomarker studies.
Acute long-distance trail running increases serum IL-6, IL-15, and Hsp72 levels
Authors: Yargic Melda Pelin , Torgutalp Seyma , Akin Senay , Babayeva Naila , Torgutalp Murat , Demirel Haydar Ali
Published: October 2018

Interleukin-6 (IL-6), IL-15, and heat shock protein 72 (Hsp72) are molecules that have significant metabolic effects on glucose and fat metabolism and a cell’s stress response. The aim of this study is to determine serum levels of these molecules in runners after a long-distance trail run. Serum IL-15 levels after such endurance events have not been investigated yet. Blood samples were collected from 37 athletes (11 female, 26 male) before and after a 35-km trail run, with a total climb of 940 m. Serum was obtained from the samples, and IL-6, IL-15, and Hsp72 levels were measured from using the sandwich ELISA method. The athletes completed the race in 308.3 ± 37.4 min on average. After the race, the mean serum IL-6, IL-15, and Hsp72 concentrations increased 13.2-fold, 2.22-fold, and 1.6-fold, respectively (p < 0.001, p < 0.001, and p = 0.039, respectively). This is the first study to demonstrate the increase in serum IL-15 levels following an acute endurance exercise. In addition to IL-15, we report that IL-6 and soluble Hsp72 levels also increased significantly following a 35-km trail run. Since these molecules are involved in regulating glucose and fat metabolism, significant increases of IL-6, IL-15, and soluble Hsp72 may have health benefits that may be associated with long-distance trail runs, which are becoming more popular worldwide.
Barcoding of parasitoid wasps (Braconidae and Chalcidoidea) associated with wild and cultivated olives in the Western Cape of South Africa
Authors: Powell Chante , Caleca Virgilio , Sinno Martina , van Staden Michaela , van Noort Simon , Rhode Clint , Allsopp Elleunorah , van Asch Barbara
Published: October 2018

Wild and cultivated olives harbor and share a diversity of insects, some of which are considered agricultural pests, such as the olive fruit fly. The assemblage of olive-associated parasitoids and seed wasps is rich and specialized in sub-Saharan Africa, with native species possibly coevolving with their hosts. Although historical entomological surveys reported on the diversity of olive wasp species in the Western Cape Province of South Africa, no comprehensive study has been performed in the region in the molecular era. In this study, a dual approach combining morphological and DNA-based methods was used for the identification of adult specimens reared from olive fruits. Four species of Braconidae and six species of Chalcidoidea were identified, and DNA barcoding methodologies were used to investigate conspecificity among individuals, based on randomly selected representative specimens. Morphological identifications were congruent with DNA data, as NJ and ML trees correctly placed the sequences for each species either at the genus or species level, depending on the available taxa coverage, and genetic distances strongly supported conspecificity. No clear evidence of cryptic diversity was found. Overall seed infestation and parasitism rates were higher in wild olives compared to cultivated olives, and highest for Eupelmus spermophilus and Utetes africanus. These results can be used for early DNA-based detection of wasp larvae in olives and to further investigate the biology and ecology of these species.
Lie symmetry analysis and some exact solutions for modified Zakharov–Kuznetsov equation
Authors: Zhou Xuan , Shan Wenrui , Niu Zhilei , Xiao Pengcheng , Wang Ying
Published: October 2018

In this study, the Lie symmetry method is used to perform detailed analysis on the modified Zakharov–Kuznetsov equation. We have obtained the infinitesimal generators, commutator table of Lie algebra and symmetry group. In addition to that, optimal system of one-dimensional subalgebras up to conjugacy is derived and used to construct distinct exact solutions. These solutions describe the dynamics of nonlinear waves in isothermal multicomponent magnetized plasmas.
Simple reflexive modules over Artin algebras
Authors: Marczinzik René
Published: October 2018

Let [Formula: see text] be an Artin algebra. It is well known that [Formula: see text] is selfinjective if and only if every finitely generated [Formula: see text]-module is reflexive. In this paper, we pose and motivate the question whether an algebra [Formula: see text] is selfinjective if and only if every simple module is reflexive. We give a positive answer to this question for large classes of algebras which include for example all Gorenstein algebras and all QF-3 algebras.
Ni Nanoparticle Anchored on MWCNT as a Novel Electrochemical Sensor for Detection of Phenol
Authors: Wang Yajing , Wang Jiankang , Yao Zhongping , Liu Chenyu , Xie Taiping , Deng Qihuang , Jiang Zhaohua
Published: October 2018

Increasing active sites and enhancing electric conductivity are critical factors to improve sensing performance toward phenol. Herein, Ni nanoparticle was successfully anchored on acidified multi-walled carbon nanotube (a-MWCNT) surface by electroless plating technique to avoid Ni nanoparticle agglomeration and guarantee high conductivity. The crystal structure, phase composition and surface morphology were characterized by XRD, SEM and TEM measurement. The as-prepared Ni/a-MWCNT nanohybrid was immobilized onto glassy carbon electrode (GCE) surface for constructing phenol sensor. The phenol sensing performance indicated that Ni/a-MWCNT/GCE exhibited an amazing detection performance with rapid response time of 4[Formula: see text]s, a relatively wide detection range from 0.01[Formula: see text]mM to 0.48[Formula: see text]mM, a detection limit of 7.07[Formula: see text][Formula: see text]M and high sensitivity of 566.2[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text]. The superior selectivity, reproducibility, stability and applicability in real sample of Ni/a-MWCNT/GCE endowed it with potential application in discharged wastewater.
L1 scheme on graded mesh for the linearized time fractional KdV equation with initial singularity
Authors: Chen Hu , Hu Xiaohan , Ren Jincheng , Sun Tao , Tang Yifa
Published: October 2018

Numerical approximation for a linearized time fractional KdV equation with initial singularity using [Formula: see text] scheme on graded mesh is considered. It is proved that the [Formula: see text] scheme can attain order [Formula: see text] convergence rate with appropriate choice of the grading parameter, where [Formula: see text] [Formula: see text] is the order of temporal Caputo fractional derivative. A fully discrete spectral scheme is constructed combing a Petrov–Galerkin spectral method for the spatial discretization, and its stability and convergence are theoretically proved. Some numerical results are provided to verify the theoretical analysis and demonstrated the sharpness of the error analysis.
Improved dielectric constant and energy density of P(VDF-HFP) composites using NBT-xST (x=0, 0.10, 0.26) whiskers
Authors: Zhou Xuefan , Wang Lu , Xue Guoliang , Zhou Kechao , Luo Hang , Zhang Dou
Published: October 2018

The high-performance energy-storage dielectric capacitors are increasingly important due to their wide applications in high power electronics. Here, we fabricated a novel P(VDF-HFP)-based capacitor with surface-modified NBT-[Formula: see text]ST ([Formula: see text], 0.10, 0.26) whiskers, denoted as Dop@NBT-[Formula: see text]ST/P(VDF-HFP). The influences of ST content, fillers’ volume fraction and electric field on the dielectric properties and energy-storage performance of the composites were investigated systematically. The results show that the dielectric constant monotonously increased with the increase of ST content and fillers’ volume fraction. The composite containing 10.0 vol% NBT-0.26ST whiskers possessed a dielectric constant of 39 at 1[Formula: see text]kHz, which was 5.6 times higher than that of pure P(VDF-HFP). It was noticed that the D-E loops of the composites became thinner and thinner with the increase of ST content. Due to the reduced remnant polarization, the composite with 5.0 vol% NBT-0.26ST whiskers achieved a high energy density of 6.18[Formula: see text]J/cm3 and energy efficiency of approximately 57% at a relatively low electric field of 200[Formula: see text]kV/mm. This work indicated that NBT-0.26ST whisker is a kind of potential ceramic filler in fabricating the dielectric capacitor with high discharged energy density and energy efficiency.
Coupling Strategies Between Asymptotic and Numerical Models with Application to Ultrasonic Non-Destructive Testing of Surface Flaws
Authors: Imperiale Alexandre , Leymarie Nicolas , Fortuna Thibaud , Demaldent Edouard
Published: October 2018

Modeling for ultrasonic testing is an important tool in industrial sectors concerned with advanced inspection methods. A significant amount of effort has been directed to building hybrid methods, which try to encompass advantages of both asymptotic and numerical methods. In our work, we consider a hybrid coupling method based upon reciprocity relations. By deriving specific formulations for the incident and diffracted fields, we apply this strategy to the case of surface and near-surface flaws. We illustrate this coupling strategy in some canonical 2D and 3D ultrasonic testing configurations.
Coupling Coefficient of Flux Density and Density Gradient of Reflected Sound Energy in Quasi-Diffuse Sound Fields
Authors: Antonov A. I. , Ledenev V. I. , Nevenchannaya T. O. , Tsukernikov I. E. , Shubin I. L.
Published: October 2018

Sound pressure levels in rooms are determined by the energy of direct sound and the energy generated by reflections of sound from enclosures. In some areas of a room, the reflected sound energy exceeds the energy of the direct sound. For this reason, calculations of the energy characteristics of reflected sound energy are of great importance. In most rooms, the reflection of sound from enclosures has a specular-diffuse character. In this case, one part of the reflected energy transferred by specular reflected waves is distributed according to the laws of geometric acoustics, and the other part, scattered diffusely, according to Lambert’s law. The calculation of the specular component of the reflected energy is made by the methods of ray tracing, and the scattered energy is calculated by the statistical energy methods developed by the authors for the quasi-diffuse sound fields of the rooms. The basis of the latter methods is the relationship between the flux density of reflected sound energy and the density gradient of this energy. The accuracy of these methods depends on the accuracy of the adopted value of the coupling coefficient between the flux density and the density gradient of the reflected sound energy. Currently, there are different ideas about its magnitude. The paper presents the results of studies of coupling coefficients with regard to space-planning and acoustic characteristics of premises. The investigations were carried out using Kuttruff’s integral equation. Based on the results obtained, recommendations are given on the choice of the coupling coefficient.
Characteristic Acoustic Impedance for Reliable Environmental Characterization
Authors: Ren Qunyan , Mo Yaxiao , Ma Li , Guo Shengming , Liao Tianjun
Published: October 2018

The characteristic acoustic impedance is a favorable observation variable for geoacoustic inversion (GI) owing to its higher sensitivity than that of pressure or particle velocity. However, no theoretical explanations have been provided for it. As an attempt to understand the underlying physical mechanism, interpretations based on the normal mode theory are conducted in this study. Moreover, synthetic Bayesian geoacoustic inversion with two recording scenarios of a vertical line array and single receiver are also performed, both of which proved that the impedance can provide improved estimation.
Super-Resolution Ultrasound Imaging Based on a Fast Full-Waveform Solver
Authors: Zhou Jianyang , Zhan Qiwei , Zeng Yan Qing , Liu Qing Huo
Published: October 2018

We propose a fast 2D full-waveform forward and inverse scattering solver to reconstruct ultrasonic speed and attenuation properties. The forward method is based on the volume integral equation, accelerated by the extended Born approximation and biconjugate-gradient fast Fourier transform method. The inverse method is based on the extended contrast source inversion. The research results show that our proposed method can fully unravel multiple scattering effects and achieve sub-wavelength resolutions. Numerical experiments indicate that the efficiency and robustness of the forward and inverse methods.
Modeling High-Frequency Backscattering from a Mesh of Curved Surfaces Using Kirchhoff Approximation
Authors: Lavia E. F. , Gonzalez J. D. , Blanc S.
Published: October 2018

The Kirchhoff approximation (K-A) to calculate the acoustic backscattering of a complex structure can be evaluated using a discretized version of its surface (i.e, a mesh). From the computational viewpoint, the most handy approach is the one based on flat facets. However, in the high-frequency range, where the K-A provides good agreement and is therefore applicable, it requires a mesh with such a large number of facets that it turns impractical. To avoid these difficulties, a mesh of curved triangles can be used to model the scatterer’s complex structure. Previous computational implementations reported in the literature did not accomplish satisfactory results for high frequency. In this work, we propose a numerical model based upon an iterative integration using Gauss–Legendre rules. The model was validated against exact solutions and led us to achieve adequate results in the high-frequency range.
B-Spline FEM for Time-Harmonic Acoustic Scattering and Propagation
Authors: Khajah Tahsin , Antoine Xavier , Bordas Stéphane P. A.
Published: October 2018

We study the application of a B-splines Finite Element Method (FEM) to time-harmonic scattering acoustic problems. The infinite space is truncated by a fictitious boundary and second-order Absorbing Boundary Conditions (ABCs) are applied. The truncation error is included in the exact solution so that the reported error is an indicator of the performance of the numerical method, in particular of the size of the pollution error. Numerical results performed with high-order basis functions (third or fourth order) showed no visible pollution error even for very high frequencies. To prove the ability of the method to increase its accuracy in the high frequency regime, we show how to implement a high-order Padé-type ABC on the fictitious outer boundary. The above-mentioned properties combined with exact geometrical representation make B-Spline FEM a very promising platform to solve high-frequency acoustic problems.
Adaptive Cross Approximation for BEM in Elasticity
Authors: Haider Anita M. , Schanz Martin
Published: October 2018

Boundary element methods (BEM) have obtained a mature state in the last years so that industrial applications are possible. However, to treat real-world problems, the so-called fast methods are necessary to reduce the original quadratic complexity to an almost linear order. Essentially, two methods are popular, the so-called fast multipole method, which uses a kernel expansion, and the algebraic approach based on [Formula: see text]-matrices with the adaptive cross approximation (ACA) to compress the matrix blocks. The latter is frequently used for scalar-valued problems, but for vector-valued problems, a modification of the pivot strategy is required. It has been suggested to search for the largest singular value out of all minimal singular values of the fundamental solution blocks. This strategy has been proposed by Rjasanow and Weggler and is studied here for elastostatics and elastodynamics. It is shown with numerical experiments that this strategy is mostly robust and results in an almost linear complexity.
Corp to cloud
Authors: Fata Matt , Arida Philippe-Joseph , Hahn Patrick , Beyer Betsy
Published: October 2018

How Google moved its virtual desktops to the cloud.
Tracking and controlling microservice dependencies
Authors: Ghirotti Silvia Esparrachiari , Reilly Tanya , Rentz Ashleigh
Published: October 2018

Dependency management is a crucial part of system and software design.
Collaborative art
Authors: Holt Whitney F. , Murphy Brittany
Published: October 2018

This forum highlights conversations at the intersection of design methods and social studies of technology. By highlighting a diversity of perspectives on design interventions and programs, we aim to forge new connections between HCI design and communication, science and technology studies, and media studies scholarship.
--- Daniela Rosner, Editor
AI, explain yourself
Authors: Monroe Don
Published: October 2018

It is increasingly important to understand how artificial intelligence comes to a decision.
The big picture
Authors: Bellovin Steven M. , Neumann Peter G.
Published: October 2018

A systems-oriented view of trustworthiness.
How machine learning impacts the undergraduate computing curriculum
Authors: Shapiro R. Benjamin , Fiebrink Rebecca , Norvig Peter
Published: October 2018

The growing importance of machine learning creates challenging questions for computing education.
Between empowerment and exploitation
Authors: Linde Per , Seravalli Anna
Published: October 2018

Community + Culture features practitioner perspectives on designing technologies for and with communities. We highlight compelling projects and provocative points of view that speak to both community technology practice and the interaction design field as a whole.
--- Christopher A. Le Dantec, Editor
SketchBlog #1
Authors: Sturdee Miriam , Lewis Makayla , Marquardt Nicolai
Published: October 2018

The
Interactions
website (interactions.acm.org) hosts a stable of bloggers who share insights and observations on HCI, often challenging current practices. Each issue we'll publish selected posts from some of the leading and emerging voices in the field.
Metformin for Treatment of Fragile X Syndrome and Other Neurological Disorders
Authors: Gantois Ilse , Popic Jelena , Khoutorsky Arkady , Sonenberg Nahum
Published: October 2018

Fragile X syndrome (FXS) is the most frequent inherited form of intellectual disability and autism spectrum disorder. Loss of the fragile X mental retardation protein, FMRP, engenders molecular, behavioral, and cognitive deficits in FXS patients. Experiments using different animal models advanced our knowledge of the pathophysiology of FXS and led to the discovery of many targets for drug treatments. In this review, we discuss the potential of metformin, an antidiabetic drug approved by the US Food and Drug Administration, to correct core symptoms of FXS and other neurological disorders in humans. We summarize its mechanisms of action in different animal and cellular models and human diseases.