bluuebunny/crossref_metadata_2025 huggingface dataset:
Update on the Role of Actovegin in Musculoskeletal Medicine: A Review of the Past 10 Years
Authors: Brock James , Golding David , Smith Paul M. , Nokes Len , Kwan Alvin , Lee Paul Y. F.
Published: January 2018

Background:

Actovegin is a biological drug with a controversial history of use in the treatment of sports injuries during the past 60 years. Particular concerns have been raised about its ergogenic potential to enhance performance, but some of these have been based on little more than anecdote.

Objectives:

In this article, we review the most recent scientific evidence to determine the clinical efficacy, safety profile, and legal status of Actovegin.

Methods:

We considered all studies directly commenting on experience with Actovegin use as the primary intervention within the past 10 years. Outcomes included mechanisms of action, clinical efficacy in enhancing muscle repair, any report of safety issues, and any evidence for ergogenic effect.

Results:

Our database search returned 212 articles, abstracts were screened, and after inclusion/exclusion criteria were applied, 25 articles were considered: Publications included 11 primary research articles (7 in vitro studies and 4 clinical trials), 8 review articles, 5 editorials, and a single case report.

Conclusions:

Current literature is still yet to define the active compound(s) of Actovegin, but suggests that it shows antioxidant and antiapoptotic properties, and may also upregulate macrophage responses central to muscle repair. Clinical efficacy was supported by one new original research article, and the use of Actovegin to treat muscle injuries remains safe and supported. Two articles argued the ergogenic effect of Actovegin, but in vitro findings did not to translate to the outcomes of a clinical trial. An adequate and meaningful scientific approach remains difficult in a field where there is immense pressure to deliver cutting-edge therapies.
Impact of Computed Tomography Evaluation Before Colonoscopy for the Management of Colonic Diverticular Hemorrhage
Authors: Ichiba Toshihisa , Hara Masahiko , Miyahara Koji , Urashima Masaki , Shintani Ayumi , Naitou Hiroshi , Higashi Reiji
Published: January 2018

Goals:

The purpose of this study was to investigate and summarize our experience of a standardized strategy using computed tomography (CT) followed by colonoscopy for the assessment of colonic diverticular hemorrhage with focus on a comparison of CT and colonoscopy findings in patients with colonic diverticular hemorrhage.

Background:

Colonic diverticular hemorrhage is usually diagnosed by colonoscopy, but it is difficult to identify the responsible bleeding point among many diverticula.

Study:

We retrospectively included 257 consecutive patients with colonic diverticular hemorrhage. All patients underwent a CT examination before colonoscopy. All-cause mortality and rebleeding-free rate after discharge were analyzed by Kaplan-Meier analysis and compared using the log-rank test.

Results:

In CT examinations, 184 patients (71.6%) had definite diverticular hemorrhage with 31.9% showing intraluminal high-density fluid on plain CT, 39.7% showing extravasation, and 31.1% showing arteriovenous increase of extravasation on enhanced CT. In colonoscopy, 130 patients (50.6%) showed endoscopic stigmata of bleeding with 12.1% showing active bleeding, 17.1% showing a nonbleeding visible vessel, and 21.4% showing an adherent clot. A comparison of the locations of bleeding in CT and colonoscopy showed that the agreement rate was 67.3%, and the disagreement rate was 0.8% when the lesion was identified by both modalities patients with definite diverticular hemorrhage identified by CT had a longer hospital stay, higher incidences of hemodynamic instability and rebleeding events than did patients with presumptive diverticular hemorrhage.

Conclusion:

CT evaluation before colonoscopy can be a good option for managing patients with colonic diverticular hemorrhage.
How to Reliably Assess Nodal Status in Distal Pancreatectomy for Adenocarcinoma
Authors: Faron Matthieu , Vuarnesson Hélène , Boher Jean-Marie , Bachellier Philippe , Sauvanet Alain , Sa Cunha Antonio , Le Treut Yves-Patrice , Mabrut Jean-Yves , Delpero Jean-Robert , Paye François
Published: January 2018

Objectives

The optimal number of lymph nodes that need to be analyzed to reliably assess nodal status in distal pancreatectomy for adenocarcinoma is still unknown.

Methods

Two hundred seventy-eight patients who underwent distal pancreatectomy for adenocarcinoma were retrieved from a retrospective French nationwide database. The relations between the number of analyzed lymph nodes and the nodal status of the tumor were studied. The beta-binomial law was used to estimate the probability of being truly node negative depending on the number of analyzed lymph nodes. Cox proportional hazard model was used for the survival analysis.

Results

The median number of analyzed lymph nodes was 15. There was a positive correlation between the number of positive lymph nodes and the number of lymph nodes analyzed. The curve reached a plateau at approximately 25 lymph nodes. The beta binomial model demonstrated that an analysis of 21 negative lymph nodes shows a probability to be truly N0 at 95%. N+ status was associated with survival, but the number of lymph node analyzed was not.

Conclusion

At least 21 lymph nodes should be analyzed to ensure a reliable assessment of the nodal status, but this number may be hard to reach in distal pancreatectomy.
Serum Immunoglobulin G4 in Discriminating Autoimmune Pancreatitis From Pancreatic Cancer
Authors: Dai Cong , Cao Qin , Jiang Min , Sun Ming-Jun
Published: January 2018

Objective

Differentiation between autoimmune pancreatitis (AIP) and pancreatic cancer (PC) is a clinical challenge. Emerging published data on the accuracy of serum immunoglobulin G4 (IgG4) for the differential diagnosis between AIP and PC are inconsistent. The objective of our study was to perform a meta-analysis evaluating the clinical utility of serum IgG4 in the differential diagnosis between AIP and PC.

Methods

We performed a systematic literature search of multiple electronic databases. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. Random-effects model was used to summarize the diagnostic odds ratio and other measures of accuracy.

Results

Eleven studies comprising 523 AIP patients and 771 PC patients were included in the meta-analysis. The summary estimates for serum IgG4 in distinguishing AIP from PC were as follows: diagnostic odds ratio, 57.30 (95% confidence interval [CI], 23.17–141.67); sensitivity, 0.72 (95% CI, 0.68–0.76); specificity, 0.93 (95% CI, 0.91–0.94). The area under the curve of serum IgG4 in distinguishing AIP from PC was 0.9200.

Conclusions

Our meta-analysis found that serum IgG4 has high specificity and relatively low sensitivity in the differential diagnosis between AIP and PC. Therefore, serum IgG4 is useful in distinguishing AIP from PC.
Modified Primary Prophylaxis in Previously Untreated Patients With Severe Hemophilia A in Iran
Authors: Karimi Mehran , Eshghi Peyman , Safarpour Mohammad M. , Haghpanah Sezaneh , Meshksar Aidin , Zahedi Zohreh , Habibpanah Behnaz
Published: January 2018

Background:

Recently the low-dose tailoring method of primary prophylaxis has been introduced for previously untreated patients with hemophilia A.

Objective:

To evaluate the efficacy and safety of low-dose tailoring method of primary prophylaxis in previously untreated patients with severe hemophilia A.

Materials and Methods:

In this pre-post interventional study, 33 patients with severe hemophilia A who were previously untreated and affiliated to universities in the capital city and southern Iran were evaluated during 2014 to 2015. Modified primary continuous prophylaxis was used for patients with age below 3 years old, after first and before the second episodes of obvious clinical bleeding in large joints or large soft tissue hematoma or large amount of bleeding. Prophylaxis was started by 25 IU/kg once per week and increased to twice or 3 times a week according to defined bleeding events.

Results:

The median age at diagnosis and age of starting prophylaxis were: 4 months (at birth, 22 mo) and 12 months (1 to 35 mo), respectively. Mean annual bleeding rate of patients after prophylaxis was 1.08±2.21 episodes per year. None of the patients had inhibitors before therapy. Inhibitor was present in 5 patients (15.1%) after prophylaxis.

Conclusions:

It seems that modified primary continuous prophylaxis has been successful in reducing bleeding episodes in children with severe hemophilia A and in the texture of lower cost it can improve quality of life of these patients, especially in developing countries where financial resources are limited.
Arterial Vascularization of the Mandibular Condyle and Fractures of the Condyle
Authors: Toure Gaoussou
Published: January 2018

Background:

Despite substantial displacements, fractures of the mandibular condyle rarely lead to necrosis. This illustrates the negligible role of the inferior alveolar artery in intraosseous supply to the condyle, and led to this systematization of its arterial vascularization.

Methods:

Forty-two temporomandibular joints from nonembalmed cadaveric specimens were studied following injection of latex (n = 32) or India ink (n = 10).

Results:

The intraosseous branches of the inferior alveolar artery that lead to the condyle were inconstant and often rudimentary. In this study, the arteries that consistently led to the condyle were the superficial temporal artery, the deep posterior temporal artery, and arterial branches leading to the lateral pterygoid muscle emanating directly from the maxillary artery. These arteries, along with the transverse facial artery and the masseteric artery (when they participated in condoyle vascularization), formed a quadrangle around the mandibular condyle. After India ink injection, the pterygoid muscle was the most strongly colored muscle, thus indicating substantial vascularization.

Conclusions:

Although there is a lack of consensus in the literature regarding the constancy and proportions of the arteries participating in vascularization of the condyle, the superficial temporal artery, the maxillary arterial branches leading to the lateral pterygoid muscle, and the deep posterior temporal artery were constant in this study. This study shows the important role of the lateral pterygoid in the vascularization of the condyle. In case of a fracture with substantial displacement, the vascularization emanating from the superficial temporal artery and the lower alveolar artery is ruptured or compromised.
Preoperative and Postoperative Assessment of Rectus Abdominis Muscle Size and Function following DIEP Flap Surgery
Authors: Seal Shane K. F. , Hewitt Mark K. , Martin Michael L. , Brasher Penelope M. A. , Macadam Sheina A.
Published: January 2018

Background:

Prospective evaluation of rectus abdominis muscle function after deep inferior epigastric artery perforator (DIEP) flap breast reconstruction is limited. Elimination of muscle harvest with this procedure is theoretically associated with preservation of rectus abdominis function and minimization of abdominal wall morbidity. In this study, the authors evaluate the change in rectus abdominis muscle size and function after DIEP flap surgery.

Methods:

Patients undergoing unilateral DIEP flap surgery were recruited prospectively. Using computed tomography, the change in preoperative to postoperative rectus abdominis muscle size was compared between the operative side rectus abdominis muscle and the contralateral, nonoperative control rectus abdominis. Postoperative muscle integrity and contractility were evaluated using ultrasound by comparing the change in rectus abdominis muscle dimensions between contractile and relaxed states. The BREAST-Q was used to score patients' subjective satisfaction. Clinical and radiographic hernia rates were also calculated.

Results:

Analysis of 26 paired rectus abdominis muscles revealed no significant change in muscle size from preoperative to postoperative values. Furthermore, dimensional change from contractile to relaxed states postoperatively was similar for paired operative and nonoperative rectus abdominis muscles. BREAST-Q scores indicated a high degree of satisfaction in abdominal well-being, breast satisfaction, and surgical experience domains. There were no clinical or radiographic abdominal wall hernias noted.

Conclusions:

The DIEP flap is an effective surgical procedure with minimal abdominal wall morbidity that is associated with no measurable loss in rectus abdominis size and contractile function postoperatively. Patients are highly satisfied with their abdominal function postoperatively using this technique.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Therapeutic, IV.
HIV Care Continuum Disparities Among Black Bisexual Men and the Mediating Effect of Psychosocial Comorbidities
Authors: Friedman M. Reuel , Sang Jordan M. , Bukowski Leigh A. , Matthews Derrick D. , Eaton Lisa A. , Raymond H. Fisher , Stall Ron
Published: January 2018

Introduction:

Differences across the HIV care continuum between men who have sex with men and women (MSMW) and men who have sex with men only (MSMO) are emerging in recent literature but have not been comprehensively documented among black MSM. Although MSMW have lower HIV prevalence than MSMO, they are more likely to be HIV-positive unaware and be virally unsuppressed. Explanatory factors for these differences have not previously been assessed.

Methods:

Between 2014 and 2016, we surveyed sexually active black MSM 18 years or older at Black Gay Pride events in 6 U.S. cities (n = 3881), 1229 of whom either self-reported HIV-positive status or tested HIV-positive onsite. We compared HIV-positive MSMW (n = 196) with HIV-positive MSMO (n = 1033) by HIV-positive unaware status, HIV care uptake, and viral load suppression. We conducted multivariable logistic regressions and built a structural equation model assessing mediating effects of psychosocial comorbidities (violence victimization, depression, and polydrug use) on the relationship between MSMW status and unsuppressed virus.

Results:

MSMW were more likely than MSMO to be HIV-positive unaware [adjusted odds ratio (aOR) = 2.17; 95% confidence interval (CI): 1.58 to 3.00]. Among those who were HIV-positive aware (n = 720), MSMW were more likely to report never receiving HIV care (aOR = 2.74; 95% CI: 1.05 to 7.16) and to report detectable viral loads (aOR = 2.34; 95% CI: 1.31 to 4.19). Psychosocial comorbidities significantly mediated (P = 0.01) the relationship between MSMW status and unsuppressed virus.

Discussion:

Black MSMW were less likely than black MSMO to uptake biomedical care and secondary prevention. Biobehavioral intervention development specific to HIV-positive black MSMW will be most successful if psychosocial comorbidities are also addressed.
Prognostic Factors Change Over Time After Hepatectomy for Colorectal Liver Metastases
Authors: Margonis Georgios Antonios , Buettner Stefan , Andreatos Nikolaos , Wagner Doris , Sasaki Kazunari , Barbon Carlotta , Beer Andrea , Kamphues Carsten , Løes Inger Marie , He Jin , Pawlik Timothy M. , Kaczirek Klaus , Poultsides George , Lønning Per Eystein , Cameron John L. , Mischinger Hans Joerg , Aucejo Federico N. , Kreis Martin E. , Wolfgang Christopher L. , Weiss Matthew J.
Published: January 2018

Objective:

To evaluate the changing impact of genetic and clinicopathologic factors on conditional overall survival (CS) over time in patients with resectable colorectal liver metastasis.

Background:

CS estimates account for the changing likelihood of survival over time and may reveal the changing impact of prognostic factors as time accrues from the date of surgery.

Methods:

CS analysis was performed in 1099 patients of an international, multi-institutional cohort. Three-year CS (CS3) estimates at the “xth” year after surgery were calculated as follows: CS3 = CS (x + 3)/CS (x). The standardized difference (d) between CS3 rates was used to estimate the changing prognostic power of selected variables over time. A d < 0.1 indicated very small differences between groups, 0.1 ≤ d < 0.3 indicated small differences, 0.3 ≤ d < 0.5 indicated moderate differences, and d ≥ 0.5 indicated strong differences.

Results:

According to OS estimates calculated at the time of surgery, the presence of BRAF and KRAS mutations, R1 margin status, resected extrahepatic disease, patient age, primary tumor lymph node metastasis, tumor number, and carcinoembryonic antigen levels independently predicted worse survival. However, when temporal changes in the prognostic impact of these variables were considered using CS3 estimates, BRAF mutation dominated prognosis during the first year (d = 0.48), whereas surgeon-related variables (ie, surgical margin and resected extrahepatic disease) determined prognosis thereafter (d ≥ 0.5). Traditional clinicopathologic factors affected survival constantly, but only to a moderate degree (0.3 ≤ d < 0.5).

Conclusions:

The impact of genetic, surgery-related, and clinicopathologic factors on OS and CS3 changed dramatically over time. Specifically, BRAF mutation status dominated prognosis in the first year, whereas positive surgical margins and resected extrahepatic disease determined prognosis thereafter.
Laparoscopic Surgery’s 100 Most Influential Manuscripts: A Bibliometric Analysis
Authors: Mellor Katie L. , Powell Arfon G.M.T. , Lewis Wyn G.
Published: January 2018

Purpose:

Bibliometric analysis of the 100 most cited manuscripts in laparoscopic surgery.

Materials and Methods:

Web of Science database was used to identify all English language full manuscripts with search terms “laparoscop*” and “surg*.” The 100 most cited publications were analyzed by; topic, journal, author, year, and institution.

Results:

In total, 71,524 eligible papers were returned with a median citation of 585.76. The 2 most cited papers received 1635 citations each. Nelson and colleagues, compared laparoscopic with open colectomy for malignancy, and Clavien and colleagues, classified postoperative morbidity by severity. Annals of Surgery published the largest number of papers (n=22), and received most citations (n=12,356). The United States (n=55) and 2004 (n=13) had the highest number of publications. The most ubiquitous topic was cancer treatment (n=35), followed by surgical technique (n=24), and comparison of laparoscopic with open surgery (n=22).

Conclusions:

The most cited topic compared laparoscopic surgical techniques and comparisons thereof with open surgery.
Fast and Flexible GPU Accelerated Binding Free Energy Calculations within the AMBER Molecular Dynamics Package
Authors: Mermelstein Daniel J. , Charles Lin , Gard Nelson , Rachael Kretsch , McCammon J. Andrew , Walker Ross C.
Published: January 2018

Alchemical free energy calculations (AFE) based on molecular dynamics (MD) simulations are key tools in both improving our understanding of a wide variety of biological processes and accelerating the design and optimization of therapeutics for numerous diseases. Computing power and theory have, however, long been insufficient to enable AFE calculations to be routinely applied in early stage drug discovery. One of the major difficulties in performing AFE calculations is the length of time required for calculations to converge to an ensemble average. CPU implementations of MD based free energy algorithms can effectively only reach tens of nanoseconds per day for systems on the order of 50,000 atoms, even running on massively parallel supercomputers. Therefore, converged free energy calculations on large numbers of potential lead compounds are often untenable, preventing researchers from gaining crucial insight into molecular recognition, potential druggability, and other crucial areas of interest. Graphics Processing Units (GPUs) can help address this. We present here a seamless GPU implementation, within the PMEMD module of the AMBER molecular dynamics package, of thermodynamic integration (TI) capable of reaching speeds of >140 ns/day for a 44,907-atom system, with accuracy equivalent to the existing CPU implementation in AMBER. The implementation described here is currently part of the AMBER 18 beta code and will be an integral part of the upcoming version 18 release of AMBER.
Nonlinear averaging of thermal experience predicts population growth rates in a thermally variable environment
Authors: Bernhardt Joey R. , Sunday Jennifer M. , Thompson Patrick L. , O’Connor Mary I.
Published: January 2018

As thermal regimes change worldwide, projections of future population and species persistence often require estimates of how population growth rates depend on temperature. These projections rarely account for how temporal variation in temperature can systematically modify growth rates relative to projections based on constant temperatures. Here, we tested the hypothesis that population growth rates in fluctuating thermal environments differ from growth rates in constant conditions, and that the differing thermal performance curves (TPCs) can be predicted quantitatively. With experimental populations of the green alga Tetraselmis tetrahele, we show that nonlinear averaging techniques accurately predicted increased as well as decreased population growth rates in fluctuating thermal regimes relative to constant thermal regimes. We extrapolate from these results to project critical temperatures for population growth and persistence of 89 phytoplankton species in naturally variable thermal environments. These results advance our ability to predict population dynamics in the context of global change.
Characterizing functional consequences of DNA copy number alterations in breast and ovarian tumors by spaceMap
Authors: Conley Christopher J. , Ozbek Umut , Wang Pei , Peng Jie
Published: January 2018

Motivation

We propose a novel conditional graphical model — spaceMap — to construct gene regulatory networks from multiple types of high dimensional omic profiles. A motivating application is to characterize the perturbation of DNA copy number alterations (CNA) on downstream protein levels in tumors. Through a penalized multivariate regression framework, spaceMap jointly models high dimensional protein levels as responses and high dimensional CNA as predictors. In this setup, spaceMap infers an undirected network among proteins together with a directed network encoding how CNA perturb the protein network. spaceMap can be applied to learn other types of regulatory relationships from high dimensional molecular pro-files, especially those exhibiting hub structures.

Results

Simulation studies show spaceMap has greater power in detecting regulatory relationships over competing methods. Additionally, spaceMap includes a network analysis toolkit for biological interpretation of inferred networks. We applied spaceMap to the CNA, gene expression and proteomics data sets from CPTAC-TCGA breast (n=77) and ovarian (n=174) cancer studies. Each cancer exhibited disruption of ‘ion transmembrane transport’ and ‘regulation from RNA polymerase II promoter’ by CNA events unique to each cancer. Moreover, using protein levels as a response yields a more functionally-enriched network than using RNA expressions in both cancer types. The network results also help to pinpoint crucial cancer genes and provide insights on the functional consequences of important CNA in breast and ovarian cancers.

Availability

The R package spaceMap — including vignettes and documentation — is hosted at https://topherconley.github.io/spacemap
An origin of the immunogenicity of in vitro transcribed RNA
Authors: Mu Xin , Greenwald Emily , Ahmad Sadeem , Hur Sun
Published: January 2018

The emergence of RNA-based therapeutics demands robust and economical methods to produce RNA with few byproducts from aberrant activity. While in vitro transcription using the bacteriophage T7 RNA polymerase is one such popular method, its transcripts are known to display an immune-stimulatory activity that is often undesirable and uncontrollable. We here showed that the immune-stimulatory activity of T7 transcript is contributed by its aberrant activity to initiate transcription from a promoter-less DNA end. This activity results in the production of an antisense RNA that is fully complementary to the intended sense RNA product, and consequently a long double-stranded RNA (dsRNA) that can robustly stimulate a cytosolic pattern recognition receptor, MDA5. This promoter-independent transcriptional activity of the T7 RNA polymerase was observed for a wide range of DNA sequences and lengths, but can be suppressed by altering the transcription reaction with modified nucleotides or by reducing the Mg concentration. The current work thus not only offers a previously unappreciated mechanism by which T7 transcripts stimulate the innate immune system, but also shows that the immune-stimulatory activity can be readily regulated.
Feasibility of particle swarm optimization and multiple regression for the prediction of an environmental issue of mine blasting
Authors: Eskandar Hajar , Heydari Elham , Hasanipanah Mahdi , Jalil Masir Mehrshad , Mahmodi Derakhsh Ali
Published: January 2018

Purpose

Blasting is an economical method for rock breakage in open-pit mines. Backbreak is an undesirable phenomenon induced by blasting operations and has several unsuitable effects such as equipment instability and decreased performance of the blasting. Therefore, accurate estimation of backbreak is required for minimizing the environmental problems. The primary purpose of this paper is to propose a novel predictive model for estimating the backbreak at Shur River Dam region, Iran, using particle swarm optimization (PSO).

Design/methodology/approach

For this work, a total of 84 blasting events were considered and five effective factors on backbreak including spacing, burden, stemming, rock mass rating and specific charge were measured. To evaluate the accuracy of the proposed PSO model, multiple regression (MR) model was also developed, and the results of two predictive models were compared with actual field data.

Findings

Based on two statistical metrics [i.e. coefficient of determination (R2) and root mean square error (RMSE)], it was found that the proposed PSO model (withR2= 0.960 and RMSE = 0.08) can predict backbreak better than MR (withR2= 0.873 and RMSE = 0.14).

Originality/value

The analysis indicated that the specific charge is the most effective parameter on backbreak among all independent parameters used in this study.
Improved plant growth simulation and genetic hybrid algorithm (PGSA-GA) and its structural optimization
Authors: Shi Kairong , Ruan Zhijian , Jiang Zhengrong , Lin Quanpan , Wang Long
Published: January 2018

Purpose

The purpose of this paper is to propose a new hybrid algorithm, named improved plant growth simulation algorithm and genetic hybrid algorithm (PGSA-GA), for solving structural optimization problems.

Design/methodology/approach

PGSA-GA is based on PGSA and three improved strategies, namely, elitist strategy of morphactin concentration calculation, strategy of intelligent variable step size and strategy of initial growth point selection based on GA. After a detailed formulation and explanation of its implementation, PGSA-GA is verified using the examples of typical truss and single-layer lattice shell.

Findings

Improved PGSA-GA was implemented and optimization was carried out for two typical optimization problems; then, a comparison was made between the PGSA-GA and other methods. The results show that the method proposed in the paper has the advantages of high efficiency and rapid convergence, which enable it to be used for the optimization of various types of steel structures.

Originality/value

Through the examples of typical truss and single-layer lattice shell, it shows that the optimization efficiency and effect of PGSA-GA are better than those of other algorithms and methods, such as GA, secondary optimization method, etc. The results show that PGSA-GA is quite suitable for structural optimization.
Iterative differential quadrature algorithms for modified Burgers equation
Authors: V.S. Aswin , Awasthi Ashish
Published: January 2018

Purpose

This paper aims to investigate the features of three vectorized iterative numerical schemes used to simulate the behavior of modified Burgers equation (MBE).

Design/methodology/approach

Two of the schemes comprise differential quadrature and finite difference methods, while the third scheme consists of only differential quadrature for the derivative approximations. Proposed schemes are simulated for well-posed problems of MBE having known the analytic solution. The computational complexity of the schemes is examined through monitoring the time taken to complete the simulation. The results are compared with the analytic solution with the help of discrete error norms. Also, the accuracy of the proposed schemes is compared with that of the existing schemes in the literature. Vectorized MATLAB programs of the schemes are used for all investigations.

Findings

It is observed that all the three schemes succeeded in producing a good replication of the exact solution. The results are closer to the analytical solution than the results in the literature. Among the three schemes, the scheme labeled as FDTDQS is found highly accurate and computationally cheaper using fewer grid points. From the vectorized MATLAB programs provided, it is evident that the implementation of the schemes is simple.

Originality/value

This study gives an idea about three numerical schemes for a highly nonlinear problem. This mathematical framework can be adopted to any one-dimensional partial differential equation as well, and the provided program will be helpful to generate more fast and accurate vectorized code in MATLAB.
Numerical algorithm of reinforced concrete lining cracking process for pressure tunnels
Authors: Zhang Wei , Dai Beibing , Liu Zhen , Zhou Cuiying
Published: January 2018

Purpose

The cracking of a reinforced concrete lining has a significant influence on the safety and leakage of pressure tunnels. This study aims to develop, validate and apply a numerical algorithm to simulate the lining cracking process during the water-filling period of pressure tunnels.

Design/methodology/approach

Cracks are preset in all lining elements, and the Mohr−Coulomb criterion with a tension cutoff is used in determining whether a preset crack becomes a real crack. The effects of several important factors such as the water pressure on crack surfaces (WPCS) and the heterogeneity of the lining tensile strength are also considered simultaneously.

Findings

The crack number and width increase gradually with the increase in internal water pressure. However, when the pressure reaches a threshold value, the increase in crack width becomes ambiguous. After the lining cracks, the lining displacement distribution is discontinuous and steel bar stress is not uniform. The measured stress of the steel bar is greatly determined by the position of the stress gauge. The WPCS has a significant influence on the lining cracking mechanism and should not be neglected.

Originality/value

A reliable algorithm for simulating the lining cracking process is presented by which the crack number and width can be determined directly. The numerical results provide an insight into the development law of lining cracks and show that the WPCS significantly affects the cracking mechanism.
Organizing inter-firm project governance – a contextual model for empirical investigation
Authors: von Danwitz Simon
Published: January 2018

Purpose

The management of major inter-firm projects requires a coherent, holistic governance framework to be effective. However, most existing models of project governance are limited to a narrow selection of contractual, structural or procedural aspects, and further neglect contextual factors, such as key characteristics of a project and its partners. The paper aims to discuss these issues.

Design/methodology/approach

This conceptual paper proposes an integrative analytical model of inter-firm project governance, building upon contingency theory and drawing from established constructs rooted in organization theory.

Findings

The paper aims to integrate two largely distinct streams of research and synthesize the respective constitutive dimensions of project governance into a coherent conceptual model. Further, interrelationships with contextual factors, such as project-related and partner-related characteristics, and project performance are discussed.

Originality/value

The proposed model purposefully merges two complementary streams of project governance research. As the model further provides clear contextual factors, it strengthens an emerging stream of project research by systematically examining external influences of project organizing. Future research may utilize this model and the suggested operationalization for each of the constructs as a basis to empirically investigate the design and effectiveness of governance regimes of major projects.
Cross-country learning in public procurement: An exploratory study
Authors: Nijboer Kimberly , Senden Shirin , Telgen Jan
Published: January 2018

All countries use public procurement to some degree to further policy objectives such as sustainability, innovation, fighting fraud and corruption, value for taxpayers' money etc. Countries may learn from past successes and failures in other countries while implementing these policies: cross-country learning. In this exploratory study, we investigate cross-country learning across two frequently used policy areas: sustainability and innovation. A threefold methodology was used that consisted of (1) an extensive review of scientific literature complemented by (2) a thorough examination of policy documents and (3) interviews with leading public procurement experts from 10 countries including both developing and developed countries. The main findings indicate that there is no hard evidence for cross-country learning. Even if cross-country learning would exist, the lessons learned seem to remain largely implicit.
Non-invasive approach to evaluate chocolate effects on weight management and blood pressure in Mexican scholars
Authors: Vázquez-Chávez Annel Europa , Torres-Ramos Yessica Dorin , Guzmán-Grenfell Alberto Martín , Gómez-Alonso Carlos , Medina-Navarro Rafael
Published: January 2018

Purpose

The purpose of the present study is to evaluate chocolate consumption effects with a non invasive metodology. There is evidence that the consumption of dark chocolate and cocoa with high flavonoid content could have positive effects on blood pressure (BP) and weight management (WM); however, there are complications at the moment of obtaining blood samples to evaluate on children at a primary school level.

Design/methodology/approach

A total of 54 healthy scholars were included; consumption of 70 per cent cacao dark chocolate was integrated into the daily snack during a 30-day period. Blood pressure, body fat, total content of polyphenols in urine and total antioxidant capacity of saliva were measured. The results obtained were divided in relation of two groups of students, A and B, with lesser or higher difficulties to WM in a self-assessment test; variables were then statistically evaluated.

Findings

Consumption of chocolate produced changes in the total content of polyphenols (from 5.6 to 6.8 µg/mL,p< 0.016) and salivary antioxidant capacity [(14.76 ± 5.4 and 16.14 ± 3.9) TEU nmol versus. t = 0;p< 0.029 andp< 0.001 at 15 and 30 days, respectively]. Group B, which presented higher difficulties concerning WM, presented a body fat reduction of about 0.63 per cent after chocolate consumption (p= 0.045) and a diastolic blood pressure reduction of −2.8 mm Hg in average (p< 0.025). A significant weight gain (p< 0.023) was observed only in Group A.

Research limitations/implications

Despite the reduced sensitivity of the non-invasive methodology, differences in urine and salivary content of polyphenols and antioxidant capacity suggest that the design used could be feasible, although extended studies are needed to corroborate it.

Originality/value

A non-invasive study for screening the potential health benefits of dark chocolate was assayed. The results suggest that dark chocolate consumption in children as part of the daily snack could be a complementary element in weight management and in prevention of future risk factors to chronic diseases.
Beyond consumption: the promising contribution of voluntary simplicity
Authors: Kraisornsuthasinee Suthisak , Swierczek Fredric William
Published: January 2018

Purpose

Greater contribution of voluntary simplicity to sustainability may extend beyond the scope of consumption behavior. This paper aims to argue that work behavior is also important and it explores how and why personal consumption of the voluntary simplifiers relates to the way they work.

Design/methodology/approach

This qualitative study uses in-depth interviews to explore the consumption–work experience relationship and driving values of voluntary simplifiers. Thailand is the chosen context, as it represents an emerging economy aiming to converge economic growth and sufficiency.

Findings

The findings demonstrate that, driven mainly by contentment and integrity, simple living complements leisurely, meaningful and, most intriguingly, ethical work. In return, such work behavior provides enough earnings and fulfills the beginners, as well as the progressive and extensive simplifiers.

Research limitations/implications

The consumption–work relationship model of the voluntary simplifiers provides an alternative starting point for further research and practice to tackle overconsumption, inequality, inequity and corruption – the critical challenges of sustainability.

Originality/value

This research takes a more complete approach to study the voluntary simplifiers. The empirical results demonstrate the greater scope of voluntary simplicity literature beyond sustainable consumption and work–life balance. Based on the consumption–work relationship driven mainly by contentment and integrity, this paper proposes meaningful and ethical work as the promising contribution of voluntary simplicity to sustainability.
Decomposition of coarse woody debris in a long‐term litter manipulation experiment: A focus on nutrient availability
Authors: Gora Evan M. , Sayer Emma J. , Turner Benjamin L. , Tanner Edmund V. J.
Published: January 2018

The majority of above‐ground carbon in tropical forests is stored in wood, which is returned to the atmosphere during decomposition of coarse woody debris. However, the factors controlling wood decomposition have not been experimentally manipulated over time scales comparable to the length of this process.

We hypothesized that wood decomposition is limited by nutrient availability and tested this hypothesis in a long‐term litter addition and removal experiment in a lowland tropical forest in Panama. Specifically, we quantified decomposition using a 15‐year chronosequence of decaying boles, and measured respiration rates and nutrient limitation of wood decomposer communities.

The long‐term probability that a dead tree completely decomposed was decreased in plots where litter was removed, but did not differ between litter addition and control treatments. Similarly, respiration rates of wood decomposer communities were greater in control treatments relative to litter removal plots; litter addition treatments did not differ from either of the other treatments. Respiration rates increased in response to nutrient addition (nitrogen, phosphorus, and potassium) in the litter removal and addition treatments, but not in the controls.

Established decreases in concentrations of soil nutrients in litter removal plots and increased respiration rates in response to nutrient addition suggest that reduced rates of wood decomposition after litter removal were caused by decreased nutrient availability. The effects of litter manipulations differed directionally from a previous short‐term decomposition study in the same plots, and reduced rates of bole decomposition in litter removal plots did not emerge until after more than 6 years of decomposition. These differences suggest that litter‐mediated effects on nutrient dynamics have complex interactions with decomposition over time.

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Determinants of Pseudogymnoascus destructans within bat hibernacula: Implications for surveillance and management of white‐nose syndrome
Authors: Verant Michelle L. , Bohuski Elizabeth A. , Richgels Katherine L. D. , Olival Kevin J. , Epstein Jonathan H. , Blehert David S.
Published: January 2018

Fungal diseases are an emerging global problem affecting human health, food security and biodiversity. Ability of many fungal pathogens to persist within environmental reservoirs can increase extinction risks for host species and presents challenges for disease control. Understanding factors that regulate pathogen spread and persistence in these reservoirs is critical for effective disease management.

White‐nose syndrome (WNS) is a disease of hibernating bats caused by Pseudogymnoascus destructans (Pd), a fungus that establishes persistent environmental reservoirs within bat hibernacula, which contribute to seasonal disease transmission dynamics in bats. However, host and environmental factors influencing distribution of Pd within these reservoirs are unknown.

We used model selection on longitudinally collected field data to test multiple hypotheses describing presence–absence and abundance of Pd in environmental substrates and on bats within hibernacula at different stages of WNS.

First detection of Pd in the environment lagged up to 1 year after first detection on bats within that hibernaculum. Once detected, the probability of detecting Pd within environmental samples from a hibernaculum increased over time and was higher in sediment compared to wall surfaces. Temperature had marginal effects on the distribution of Pd. For bats, prevalence and abundance of Pd were highest on Myotis lucifugus and on bats with visible signs of WNS.

Synthesis and applications. Our results indicate that distribution of Pseudogymnoascus destructans (Pd) within a hibernaculum is driven primarily by bats with delayed establishment of environmental reservoirs. Thus, collection of samples from Myotis lucifugus, or from sediment if bats cannot be sampled, should be prioritized to improve detection probabilities for Pd surveillance. Long‐term persistence of Pd in sediment suggests that disease management for white‐nose syndrome should address risks of sustained transmission from environmental reservoirs.
Exploitation of the Ultraviolet Properties and Machine Cut Edges of Paper to Associate and Sequence Sheets in a Ream
Authors: Musgrave Nicola R. , Thorne Oliver T. S.
Published: January 2018

Previously unreported line patterns visible under ultraviolet light were observed on a proportion of plain white A4 printer/copier paper from different manufacturers. These Ultraviolet Line Patterns (UVLPs) usually appear as stripes down the vertical length of the paper. Typically, theUVLPs were found to “repeat” through the ream in a predictable way, while also changing. It is postulated that the repeating nature of theUVLPs is a result of the way that paper is manufactured. This leads to the ability to sequence the sheets compared to their original source paper. Even in the absence ofUVLPs, it is possible to use our observation of the manufacturing process to anticipate the order of several sheets of paper and conclusively associate them, in some cases, by physically fitting their machine cut edges and crossing paper fibers. Such a novel approach to examining questioned documents would be highly useful in forensic casework.
Predictors and consequences of health anxiety symptoms: a novel twin modeling study
Authors: López‐Solà C. , Bui M. , Hopper J. L , Fontenelle L. F. , Davey C. G. , Pantelis C. , Alonso P. , van den Heuvel O. A. , Harrison B. J.
Published: January 2018

Objective

The question of how to best conceptualize health anxiety (HA) from a diagnostic and etiological perspective remains debated. The aim was to examine the relationship between HA and the symptoms of anxiety and obsessive–compulsive‐related disorders in a normative twin population.

Method

Four hundred and ninety‐six monozygotic adult twin pairs from the Australian Twin Registry participated in the study (age, 34.4 ± 7.72 years; 59% females). Validated scales were used to assess each domain. We applied a twin regression methodology—ICE FALCON—to determine whether there was evidence consistent with ‘causal’ relationships between HA and other symptoms by fitting and comparing model estimates.

Results

Estimates were consistent with higher levels of obsessing (‘unwanted thoughts’) (P = 0.008), social anxiety (P = 0.03), and body dysmorphic symptoms (P = 0.008) causing higher levels of HA symptoms, and with higher levels of HA symptoms causing higher levels of physical/somatic anxiety symptoms (P = 0.001).

Conclusion

Obsessional thoughts, body dysmorphic concerns, and social anxiety symptoms may have a causal influence on HA. To report physical/somatic anxiety appears to be a consequence of the underlying presence of HA‐related fears. Should our results be confirmed by longitudinal studies, the evaluation and treatment of HA may benefit from the consideration of these identified risk factors.
Decreased retinal sensitivity in depressive disorder: a controlled study
Authors: Berman G. , Muttuvelu D. , Berman D. , Larsen J. I. , Licht R. W. , Ledolter J. , Kardon R. H.
Published: January 2018

Objective

To compare pupil responses in depressed patients with a seasonal pattern, depressed patients without a seasonal pattern and healthy controls as a function of daylight hours on the testing day.

Method

Patients suffering from a major depressive episode were included in wintertime. The pupil light reflex was measured at inclusion and in the following summer using a binocular pupillometer. A protocol of low (1 lux) and high (400 lux) intensity red and blue lights was used to assess rod, cone and melanopsin‐containing intrinsic photosensitive retinal ganglion cell input to the pupil reflex.

Results

The mean group pupil responses associated with a melanopsin‐mediated sustained pupil response at 400 lux blue light were significantly reduced in the depressed subjects (N = 39) as compared to the healthy controls (N = 24) (P = 0.023). Across all groups, a reduction in number of daylight hours was significantly associated with a reduction in sustained pupil response (P = 0.007). All groups showed an equal effect of daylight hours on the melanopsin‐mediated sustained pupil response.

Conclusion

The melanopsin‐mediated sustained pupil contraction to offset of high‐intensity blue light is reduced in depressed patients. These results further emphasize the interaction of light exposure with depression.