bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental evolution ofCandida albicansunder hypoxia and heat shock reveals nuclear genome variants and mitochondrial methylome alterations
Authors: Bartelli Thais Fernanda , Bruno Danielle do Carmo Ferreira , Lichtenstein Flavio , Briones Marcelo R. S.
Published: July 2017

Infection byCandida albicansrequires its adaption to physical constraints in the human body, such as low oxygen tension (hypoxia), increased temperature (37°C) and different carbon sources. Previous studies demonstrated that the genetic variability ofC. albicansisolates is an important adaptive mechanism, although little is known about the dynamics of this genetic diversity, and the influence of these environmental conditions on its mitochondrial genome (mtDNA). To test the synergistic effect of these stress conditions onC. albicansgenome, reference strain SC5314 was subjected to anin vitroevolution scheme under hypoxia and 37°C, with two different carbon sources (glycerol and dextrose) for up to 48 weeks (approximately 4,000 generations). Experimental evolution results showed no sequence or copy number changes in the mtDNA, although sequence variants were detected on its nuclear genome by Multilocus sequence typing (MLST) and whole genome sequencing (WGS). After 12 weeks of experimental evolution, sample GTH12, grown under hypoxia at 37°C in glycerol, showed inferior growth and respiratory rates as compared to other conditions tested. Although WGS of GTH12 revealed no variants in its mtDNA, WGS with sodium bisulfite showed a significant reduction in mtDNA methylation in GTH12 in both non-coding and coding regions. Our results provide the first whole mitochondrial genome methylation map ofC. albicansand show that environmental conditions promote the selective growth of specific variants and affect the methylation patterns of the mtDNA in a strain-specific manner.
A novel flatworm-specific gene family implicated in reproduction inMacrostomum lignano
Authors: Grudniewska Magda , Mouton Stijn , Grelling Margriet , Wolters Anouk H. G. , Kuipers Jeroen , Giepmans Ben N. G. , Berezikov Eugene
Published: July 2017

Free-living flatworms, such as the planarianSchmidtea mediterranea, are extensively used as model organisms to study stem cells and regeneration. The majority of studies in planarians so far focused on broadly conserved genes. However, investigating what makes these animals different might be equally informative for understanding its biology. Here, we present a re-analysis of neoblast and germline transcriptional signatures in the flatwormM. lignanoand combine it with the whole-animal electron microscopy atlas (nanotomy) as a reference platform for ultrastructural studies inM. lignano. We show that germline-enriched genes have a high fraction of flatworm-specific genes and identifyMlig-sperm1gene as a member of a novel gene family conserved only in free-living flatworms and essential for producing healthy spermatozoa. This work demonstrates that investigation of flatworm-specific genes is crucial for understanding flatworm biology and establishes a basis for future research in this direction inM. lignano.
Functional Diversification of Tripeptidyl Peptidase and Endopeptidase Sedolisins in Fungi
Authors: Orts Facundo , Have Arjen ten
Published: July 2017

Sedolisins are acid proteases that are related to the basic subtilisins. They have been identified in all three superkingdoms but are not ubiquitous, although fungi that secrete acids as part of their lifestyle can have up to six paralogs. Both tripeptidyl peptidase (TPP) and endopeptidase activity have been identified and it has been suggested that these correspond to separate subfamilies.

We studied eukaryotic sedolisins by computational analysis. A maximum likelihood tree shows three major clades of which two contain only fungal sequences. One fungal clade contains all known TPPs whereas the other contains the endosedolisins. We identified four cluster specific inserts (CSIs) in endosedolisins, of which CSIs 1, 3 and 4 appear as solvent exposed according to structure modeling. Part of CSI2 is exposed but a short stretch forms a novel and partially buried α-helix that induces a conformational change near the binding pocket. We also identified a total of 12 specificity determining positions (SDPs) divided over three SDP sub-networks. The major SDP network contains eight directly connected SDPs and modeling of virtual mutants suggests a key role for the W307A or F307A substitution. This substitution is accompanied by a group of four SDPs that physically interact at the interface of the catalytic domain and the enzyme’s prosegment. Modeling of virtual mutants suggests these SDPs are indeed required to compensate the conformational change induced by CSI2 and the A307. The additional major network SDPs as well as the two small SDP networks appear to be linked to this major substitution, all together explaining the hypothesized functional diversification of fungal sedolisins.

Highlights

There are two sedolisin subfamilies in fungi: tripeptidyl peptidases and endopeptidases

Functional Diversification of fungal sedolisins led to a conformational change in the pocket

Functional Diversification centers around buried SDP307

SDP307 is aromatic in TPPs and Alanine in endosedolisins

Additional SDPs affect the interaction between core and chaperone-like prosegment
ESCRT-Independent Surface Receptor And Transporter Protein Degradation By The ILF Pathway
Authors: McNally Erin Kate , Brett Christopher Leonard
Published: July 2017

Surface receptor and transporter protein down-regulation drives cell signaling, quality control and metabolism underlying diverse physiology. After endocytosis, proteins are delivered to endosomes where ESCRTs package them into intralumenal vesicles, which are degraded by acid hydrolases upon fusion with lysosomes. However, reports of ESCRT-independent surface protein degradation are emerging suggesting that alternative, non-canonical pathways exist. UsingSaccharomyces cerevisiaeas a model, here we show that in response to substrates, protein misfolding or TOR signaling, some internalized surface transporters (Hxt3, Itr1, Aqr1) bypass ESCRTs en route to the lysosome membrane where they are sorted into an area that is internalized as an intralumenal fragment (ILF) and degraded upon organelle fusion. This ILF pathway also degrades typical ESCRT client proteins (Mup1, Can1, Ste3) when ESCRT function is impaired. As the underlying machinery is conserved, we speculate that the ILF pathway is an important contributor to receptor and transporter down-regulation in all eukaryotes.
The mitotic spindle is chiral due to torques generated by motor proteins
Authors: Novak Maja , Polak Bruno , Simunić Juraj , Boban Zvonimir , Kuzmić Barbara , Thomae Andreas W. , Tolić Iva M. , Pavin Nenad
Published: July 2017

Mitosis relies on forces generated in the spindle, a micro-machine composed of microtubules and associated proteins1,2. Forces are required for the congression of chromosomes to the metaphase plate and separation of chromatids in anaphase3-6. However, torques may also exist in the spindle, yet they have not been investigated. Here we show that the spindle is chiral. Chirality is evident from the finding that microtubule bundles follow a left-handed helical path, which cannot be explained by forces but rather by torques acting in the bundles. STED super-resolution microscopy, as well as confocal microscopy, of human spindles shows that the bundles have complex curved shapes. The average helicity of the bundles with respect to the spindle axis is 1.2°/μm. Inactivation of kinesin-5 (Eg5/Kif11) abolished the chirality of the spindle, suggesting that this motor generates the helical shape of microtubule bundles. To explain the observed shapes, we introduce a theoretical model for the balance of forces and torques acting in the spindle, and show that torque is required to generate the helical shapes. We conclude that torques generated by motor proteins, in addition to forces, exist in the spindle and determine its architecture.
Closing the strategy execution gap through business simulations
Authors: Monauni Max
Published: July 2017

Purpose

The purpose of this paper is to outline the relevance of a well-defined and well-led strategy execution process with respect to corporate success. It proposes customized business simulations as an effective solution for a smooth strategy execution.

Design/methodology/approach

Business simulations can help to bridge the strategy–execution gap. To illustrate this, three representative real-life business cases from different industries are described and analyzed, which successfully utilized simulation-based strategy implementation.

Findings

Recent studies have shown that poor alignment between the executive board and the operational business levels, insufficient understanding as well as a lack of accountability within the process are the key reasons for faulty strategy execution. Bespoke business simulations can address these issues.

Originality/value

There are several existing tools for strategy execution at hand. However, business simulations strongly increase the personal involvement of the employees by fostering high interactivity and gamification to boost the strategy transformation process.
Ways of working between third sector organizations and UK universities: are we getting it right?
Authors: Fearon Colm , Sama Antonio , van Vuuren Wim
Published: July 2017

Purpose

The purpose of this paper is to offer strategic advice and identify ways in which third sector organizations can work with United Kingdom (UK) universities for promoting business education and enterprise skills development.

Design/methodology/approach

The authors’ strategic advice is based on analysis of qualitative interviews, focus groups, interactive seminars/workshops, and working with third sector support agencies.

Findings

Advice for third sector organizations includes the following points: build your efficacy – share the burden, do not attempt everything on your own; partner, or own the business skills yourself – you decide upon your strategy; develop your “social mission” and be “business oriented”; develop applied student projects – everyone wins; think about student volunteers; and local universities are there for you – check and see.

Originality/value

This is the first article of Development and Learning in Organization (DLO) to consider relationships between UK’s third sector organizations and regional universities. The authors deal with important education, skills, and business development issues for the third sector. There are new opportunities in 2016 (and beyond) for universities to build closer relationships with their third sector communities.
Workplace integration: the lived experiences of highly skilled migrants in Australia
Authors: Rajendran Diana , Farquharson Karen , Hewege Chandana
Published: July 2017

Purpose

The purpose of this paper is to explore how highly skilled migrants to Australia integrate into the workplace, focussing on the factors that foster or hinder that integration.

Design/methodology/approach

An inductive method using an interpretive methodological approach was employed. In-depth interview data were analysed thematically.

Findings

Informal workplace practices, such as informal peer mentoring and having an “empathetic” supervisor, also assisted with integration, as did migrant self-help strategies. Factors hindering integration included structural barriers outside the organisation and workplace factors such as racism, cultural barriers and individual factors that centred on the migrants themselves.

Research limitations/implications

While the exploratory qualitative enquiry sheds light on issues of concern regarding workplace integration of skilled migrants, further studies with diverse migrant groups would be required to understand if the findings could be replicated. An industry or sector-wise migrant study would shed more light on the issues.

Practical implications

Fostering and hindering factors identified through the lens of four workplace integration theories can inform workplace integration strategies and related policy formulation.

Originality/value

Informed by four theories of integration, the findings shed light on the everyday workplace experiences of linguistically competent, self-initiated, highly skilled migrants from diverse ethnic/cultural backgrounds in Australian workplaces in a range of industries. While previous research has identified problems experienced by migrants at work, this paper explores factors fostering and hindering workplace integration through the lens of the lived experiences of skilled migrant workers.
Evaluating impact of 5S implementation on business performance
Authors: Randhawa Jugraj Singh , Ahuja Inderpreet Singh
Published: July 2017

Purpose

The purpose of this research paper is to evaluate the contributions of 5S implementation in the Indian manufacturing industries and its impact on the enhancement of their business performance.

Design/methodology/approach

The research study has been accomplished in the large number of manufacturing organizations that have successfully imbibed the 5S technique or are in the process of implementing 5S initiatives alone or along with other lean manufacturing practices. An elaborated “5S Questionnaire” has been designed to determine the contextual factors and their impact on the enhancement of business performance.

Findings

The results reveal that the majority of organizations have shown total commitment toward the implementation and objective realization of 5S quality policy at all levels in the organizations. The implementation of 5S has facilitated manufacturing organizations to accrue significant benefits such as improvement in overall organizational, productivity, quality, safety, employee morale values, effective workspace utilization, and cost optimizations. The results also show the elimination of serious chronic manufacturing system problems such as delays, breakdown, demoralized employees, declining profits, and dissatisfied customers through holistic 5S implementation.

Research limitations/implications

The limitation of the study is that it encompasses only the manufacturing organizations, while a similar study can also be conducted in services sector also.

Originality/value

The study highlights the detailed contributions of 5S principles in the development of manufacturing organizations and its impact on the enhancement of business performance for remaining competitive in global market world.
Cost consequence of failure in failure mode and effect analysis
Authors: Guinot Jeff , Sinn John W. , Badar M. Affan , Ulmer Jeffrey M.
Published: July 2017

Purpose

The purpose of this paper is to investigate the possibility of including the cost consequence of failure in the a priori risk assessment methodology known as failure mode and effect analysis (FMEA).

Design/methodology/approach

A model of the standard costs that are incurred when an electronic control module in an automotive application fails in service was developed. These costs were related to the Design FMEA ranking of the level of severity of the failure mode and the probability of its occurrence. Monte Carlo simulations were conducted to establish the average costs expected for each level of severity at each level of occurrence. The results were aggregated using fuzzy utility sets into a nine-point ordinal scale of cost consequence. The criterion validity of this scale was assessed with warranty cost data derived from a case study.

Findings

It was found that the model slightly underestimated the warranty costs that accrued, but the fit could be improved with adjustments dictated by actual usage conditions.

Research limitations/implications

Cost data used in the simulations were derived from government and academic surveys, analyses, and estimates of the manufacturing cost structure; and nominal costs for various quality issues experienced by Tier 2 automotive electronics supplier. Specificity is lacking. The sample size and the type of the failure modes used to validate the model are constrained by the number and type of products which have had demonstrable performance concerns over the past three years, with cost data available to the authors. The power of the validation is limited. The validation is considered a screening assessment.

Practical implications

This work relates the characterization of risk with its potential cost and develops a scaling instrument to allow the incorporation of cost consequence into an FMEA.

Originality/value

A ranking scale was developed that related severity and occurrence rank scores to a cost consequence rank that keys to a cost of quality figure (given as percent of sales) that would accompany a realization of the failure mode.
Halal risk management: combining robustness and resilience
Authors: Tieman Marco
Published: July 2017

Purpose

The purpose of this paper is to introduce a supply chain view of a robust and resilient halal brand. In this conceptual paper, a risk prevention-mitigation-recovery cycle is proposed.

Design/methodology/approach

This paper builds further on previous work published in theJournal of Islamic Marketingon Islamic branding and halal supply chain management. Hypotheses are developed on the intensity of risk management.

Findings

Integrity of halal products is becoming an increasing concern for governments and industries. Three halal supply chain risk cycles are proposed: (1) risk prevention: risk vulnerability assessment, supply chain (re)design, vertical and horizontal collaboration, monitoring; (2) risk mitigation: investigative audits, cross-functional team, risk mitigation and communication plan, monitoring; and (3) risk recovery: risk recovery and communication plan, resume operations, maintain employee support, review risk mitigation and recovery plans.

Research limitations/implications

This conceptual paper proposes three halal supply chain risk cycles to better organise risk management in halal supply chains. However, more empirical research on halal risk management is needed to validate these risk management cycles.

Practical implications

To better protect halal brands and corporate reputation, there are evident benefits of extending halal assurance towards the supply chain, for which prevention-mitigation-recovery cycles are proposed.

Originality/value

As halal is going through an evolution, towards a halal supply chain and value chain, halal-certified brands need better protection. It is the first study investigating halal risk and reputation management for halal-certified brands.
A hybrid MCDM approach for performance evaluation in the banking industry
Authors: Beheshtinia Mohammad Ali , Omidi Sedighe
Published: July 2017

Purpose

This paper aims to propose a hybrid multiple criteria decision-making (MCDM) technique for performance evaluation of banks in which the banks are assessed and ranked according to the criteria of the balanced scorecard (BSC) methodology and corporate social responsibility (CSR) views.

Design/methodology/approach

To clarify the performance of the proposed model, the MCDM technique was implemented in four banks in Iran as a pilot. First, proper criteria for banking industry are identified considering BSC and CSR. Consequently, analytic hierarchy process (AHP) and modified digital logic (MDL) techniques are used to determine the weights of criteria. The banks are ranked by fuzzy TOPSIS (FTOPSIS) and fuzzy VIKOR (FVIKOR). Using a combination of these techniques, four methods, namely, AHP-FTOPSIS, AHP-FVIKOR, MDL-FTOPSIS and MDL-FVIKOR, are obtained, each of which provides a different set of rankings for banks. Eventually, the obtained ranks are integrated using the Copeland method.

Findings

The results showed that the return on investment, debt ratio and lower energy consumption criteria are the most important, and enhancement of brand value, increasing customer loyalty and environmental care criteria have the lowest percentage of importance. Also, the final bank ranking is determined by the proposed method.

Originality/value

This paper identifies 6 criteria and 25 sub-criteria for evaluating the banks considering BSC and CSR viewpoints including some new sub-criteria that has not been considered before. Moreover, these hybrid approaches and especially MDL techniques have not been used by previous researchers.
Food waste conversion to microbial polyhydroxyalkanoates
Authors: Nielsen Chad , Rahman Asif , Rehman Asad Ur , Walsh Marie K. , Miller Charles D.
Published: July 2017

Polyhydroxyalkanoates (PHAs) are biopolymers with desirable material properties similar to petrochemically derived plastics. PHAs are naturally produced by a wide range of microorganisms as a carbon storage mechanism and can accumulate to significantly high levels. PHAs are an environmentally friendly alternative to their petroleum counterparts because they can be easily degraded, potentially reducing the burden on municipal waste systems. Nevertheless, widespread use of PHAs is not currently realistic due to a variety of factors. One of the major constraints of large‐scale PHA production is the cost of carbon substrate for PHA‐producing microbes. The cost of production could potentially be reduced with the use of waste carbon from food‐related processes. Food wastage is a global issue and therefore harbours immense potential to create valuable bioproducts. This article's main focus is to examine the state of the art of converting food‐derived waste into carbon substrates for microbial metabolism and subsequent conversion into PHAs.
FXa inhibition by rivaroxaban modifies mechanisms associated with the pathogenesis of human abdominal aortic aneurysms
Authors: Moñux Guillermo , Zamorano‐León Jose J. , Marqués Pablo , Sopeña Bernardo , García‐García J. M. , Laich de Koller G. , Calvo‐Rico Bibiana , García‐Fernandez Miguel A. , Serrano J. , López‐Farré Antonio
Published: July 2017

Aims

To evaluate if rivaroxaban, an oral factor Xa (FXa) inhibitor, could modify the expression in vitro of inflammatory and oxidative stress biomarkers in abdominal aortic aneurysmal (AAA) sites showing intraluminal thrombus.

Methods

AAA sites with intraluminal mural thrombus were obtained from six patients undergoing elective AAA repair. In addition, control abdominal aortic samples were obtained from six organ donors. AAA sites were incubated in the presence and absence of 50 nmol l–1 rivaroxaban.

Results

AAA sites showing thrombus demonstrated higher content of FXa than control. Interleukin‐6 levels released from AAA [Control: median: 23.45 (interquartile range: 16.17–37.15) vs. AAA: median: 153.07 (interquartile range: 100.80–210.69) pg ml–1 mg tissue–1, P < 0.05] and the expression levels of nitric oxide synthase 2 were significantly higher in AAA than in control. The protein expression level of NADPH oxidase subunits gp67‐and gp91‐phox, but did not gp47‐phox, were also significantly higher in the AAA sites than in control. Addition of rivaroxaban to AAA sites explants significantly reduced the release of interleukin‐6 [median: 51.61 (interquartile range: 30.87–74.03) pg ml–1 mg tissue–1, P < 0.05 with respect to AAA alone] and the content of nitric oxide synthase 2, gp67 and gp91‐phox NADPH subunits. The content of matrix metallopeptidase 9 was significantly higher in the AAA sites as compared to control. Rivaroxaban also reduced matrix metallopeptidase 9 content in AAA sites to similar levels to control.

Conclusions

FXa inhibition by rivaroxaban exerted anti‐inflammatory and antioxidative stress properties in human AAA sites, suggesting a role of FXa in these mechanisms associated with the pathogenesis of AAA.
Parenting and Cortisol in Infancy Interactively Predict Conduct Problems and Callous–Unemotional Behaviors in Childhood
Authors: Wagner Nicholas J. , Mills‐Koonce W. Roger , Willoughby Michael T. , Cox Martha J. ,   Family Life Project Key Investigators
Published: July 2017

This study examines observed maternal sensitivity, harsh‐intrusion, and mental‐state talk in infancy as predictors of conduct problems (CP) and callous–unemotional (CU) behaviors in middle childhood, as well as the extent to which infants’ resting cortisol and cortisol reactivity moderate these associations. Using data from the Family Life Project (n = 1,292), results indicate that maternal sensitivity at 6 months predicts fewer CP at first grade, but only for infants who demonstrate high levels of cortisol reactivity. Maternal harsh intrusion predicts fewer empathic–prosocial behaviors, a component of CU behaviors, but only for infants who demonstrate high resting cortisol. Findings are discussed in the context of diathesis–stress and differential susceptibility models.
Nucleoside reverse transcriptase inhibitor‐reducing strategies in HIV treatment: assessing the evidence
Authors: Orkin C , Llibre JM , Gallien S , Antinori A , Behrens GMN , Carr A
Published: July 2017

Antiretroviral (ARV) therapy, comprising a backbone of two nucleos(t)ide reverse transcriptase inhibitors (NRTIs) plus another ARV, is the recognized standard of care (SOC), which has helped extend life expectancy in people living with HIV. In a quest to reduce lifelong drug exposure and minimize or avoid the toxicity of NRTIs, “NRTI‐reducing” regimens have been investigated. This descriptive review assessing the results of NRTI‐reducing strategies from the largest randomized trials focuses on virological efficacy, resistance, regimen safety (in terms of bone mineral density, renal function, lipids and central nervous system function) and simplicity. The review considers efficacy across various NRTI‐sparing strategies, for example an integrase strand transfer inhibitor (INSTI) plus a ritonavir‐boosted protease inhibitor (PI/r) or PI/r + lamivudine (3TC), in both naïve and switch regimes. Of 10 key studies in treatment‐naïve adults assessing five NRTI‐reducing strategies, only four studies demonstrated noninferiority vs. SOC [GARDEL, NEAT 001, AIDS Clinical Trials Group 5142 and PROGRESS]. In switch settings, 17 studies (10 randomized) were reviewed that used four strategies, including three studies assessing an INSTI plus a nonnucleoside reverse transcriptase inhibitor . Noninferiority of the NRTI‐reducing arm was shown in six of 10 studies (ATLAS‐M, SALT, DUAL, OLE, LATTE‐2 and SWORD). In general, NRTI‐reducing therapy did not always result in an improvement in short‐ or long‐term adverse events; however, in many cases, these endpoints were not reported. Some of these studies reported higher virological failure rates with more frequent emergence of resistance mutations. None of these NRTI‐reducing strategies has been compared against a single‐pill regimen, including those containing tenofovir alafenamide. Only strategies demonstrating noninferior efficacy, a benefit in safety/tolerability, and a favourable cost‐efficacy ratio, preferably in a single pill, will eventually match the current SOC of triple ARV therapy.
Customers’ perceptions of and satisfaction with medicine retail outlet services in Addis Ababa, Ethiopia: a cross-sectional study
Authors: Gebregeorgise Dawit T , Mohammed Tofik A , Redi Zebiba S , Sporrong Sofia Kälvemark
Published: July 2017

Objectives

The aim of this study was to assess customers' perceptions of and satisfaction with MRO services in Addis Ababa and to explore factors associated with their satisfaction and reasons for visits.

Methods

A cross-sectional survey was conducted among customers selected from 28 MROs in Addis Ababa, using multi-stage sampling techniques. Simple descriptive statistics and multivariable logistic regression at 95% confidence interval were used for the analysis.

Key findings

Of 396 respondents, 324 (81.8%) visited MROs to purchase prescription medicines. A majority (338/396; 85.4%) of them perceived that pharmacists and druggists (pharmacy professionals) play a major role in healthcare delivery. A third (140/396; 35.4%) of the respondents agreed with the statement that pharmacy professionals are more concerned about patient care than about their business. Regarding reasons for visiting, being married was positively associated with buying over-the-counter, higher educational status was linked with more satisfaction. Overall, 56.8% (225/396) of the respondents reported that they were satisfied with the service provided by MROs.

Conclusion

Customers of MROs had mixed perceptions of and satisfaction with the current service. Marital status and age were associated with the reason for visiting, while the educational level was associated with the level of satisfaction. The overall positive perceptions and satisfaction about MROs should be taken as an opportunity to promote and improve pharmaceutical services rendered in MROs, to ensure that the public is receiving maximum benefit.
How do Independent Directors Influence Corporate Risk‐Taking? Evidence from a Quasi‐Natural Experiment
Authors: Jiraporn Pornsit , Lee Sang Mook
Published: July 2017

Motivated by agency theory, we explore the effect of independent directors on corporate risk taking. To minimize endogeneity, we exploit the passage of the Sarbanes–Oxley Act as an exogenous shock that raises board independence. Our difference‐in‐difference estimates show that board independence diminishes risk‐taking significantly, as evidenced by the substantially lower volatility in the stock returns. In particular, board independence reduces total risk and idiosyncratic risk by 24.87% and 12.60%, respectively. The evidence is consistent with the notion that board independence represents an effective governance mechanism that prevents managers from taking excessive risk. Additional analysis based on propensity score matching also confirms our results. Our research design is based on a natural experiment and is far more likely to show causality, rather than merely an association.
Longitudinal MR Spectroscopy Shows Altered Metabolism in Traumatic Brain Injury
Authors: Maudsley Andrew A. , Govind Varan , Saigal Gaurav , Gold Stuart G. , Harris Leo , Sheriff Sulaiman
Published: July 2017

BACKGROUND AND PURPOSE

Brain trauma is known to result in heterogeneous patterns of tissue damage and altered neuronal and glial metabolism that evolve over time following injury; however, little is known on the longitudinal evolution of these changes. In this study, magnetic resonance spectroscopic imaging (MRSI) was used to map the distributions of altered metabolism in a single subject at five time points over a period of 28 months following injury.

METHODS

Magnetic resonance imaging and volumetric MRSI data were acquired in a subject that had experienced a moderate traumatic brain injury (Glasgow Coma Scale 13) at five time points, from 7 weeks to 28 months after injury. Maps of N‐acetylaspartate (NAA), total choline (Cho), and total creatine signal were generated and differences from normal control values identified using a z‐score image analysis method.

RESULTS

The z‐score metabolite maps revealed areas of significantly reduced NAA and increased Cho, predominately located in frontal and parietal white matter, which evolved over the complete course of the study. A map of the ratio of Cho/NAA showed the greatest sensitivity to change, which indicated additional metabolic changes throughout white matter. The metabolic changes reduced over time following injury, though with abnormal values remaining in periventricular regions.

CONCLUSIONS

The use of z‐score image analysis for MRSI provides a method for visualizing diffuse changes of tissue metabolism in the brain. This image visualization method is of particularly effective for visualizing widespread and diffuse metabolic changes, such as that due to traumatic injury.
Consequence and Normative Guidance
Authors: Steinberger Florian
Published: July 2017

Logic, the tradition has it, is normative for reasoning. But is that really so? And if so, in what sense is logic normative for reasoning? As Gilbert Harman has reminded us, devising a logic and devising a theory of reasoning are two separate enterprises. Hence, logic's normative authority cannot reside in the fact that principles of logic justarenorms of reasoning. Once we cease to identify the two, we are left with a gap. To bridge the gap one would need to produce what John MacFarlane has appropriately called abridge principle, i.e. a general principle articulating a substantive and systematic link between logical entailment and norms of reasoning. This is Harman'sskeptical challenge. In this paper I argue that Harman's skeptical challenge can be met. I show how candidate bridge principles can be systematically generated and evaluated against a set of well‐motivated desiderata. Moreover, I argue that bridge principles advanced by MacFarlane himself and others, for all their merit, fail to address the problem originally set forth by Harman and so do not meet the skeptical challenge. Finally, I develop a bridge principle that meets Harman's requirements as well as being substantive.
Electrospun Sodium-Cobalt Oxide Ceramic Nanofiber and the Electromagnetic Responses
Authors: Bautista Arturo G. , Aguado Juan A. , Gan Yong X.
Published: July 2017

In this work, a sodium-cobalt oxide (NaxCo2O4) ceramic composite nanofiber was manufactured through electrospinning. The response of the fiber to external electromagnetic field was characterized to observe the heat generation in the fiber. In addition, we also measured the current passing through the fiber under the polarization of DC potential. It is found that the fiber has intensive heating behavior when it is exposed to the electromagnetic field. The temperature increases more than 5 degrees in Celsius scale only after 5 s exposure. The current – potential curve of the fiber reveals its dielectric behavior. It is concluded that this ceramic fiber has the potential to be used for hyperthermia treatment in biomedical engineering or for energy conversions.
Plasmonic Nanofocusing in Deep and Extreme Sub-Wavelength Scale for Scalable Nanolithography
Authors: Du Zhidong , Chen Chen , Pan Liang
Published: July 2017

Maskless nanolithography is an agile and cost effective approach if their throughputs can be scaled for mass production purposes. Using plasmonic nanolithography approach, direct pattern writing was successfully demonstrated with 22 nm half-pitch at high speed. Plasmonic nanolithography uses an array of plasmonic lenses to directly pattern features on a rotating substrate. Taking the advantage of air bearing surface techniques, the system can expose the wafer pixel by pixel with a speed of ∼10 m/s, much faster than any conventional scanning based lithography system. It is a low-cost, high-throughput maskless approach for the next generation lithography and also for the emerging nanotechnology applications, such as nanoscale metrology and imaging. A critical part of the PNL is to use plasmonic lens to deliver highly concentrated optical power at nanoscale. We have demonstrated such nanoscale process and achieved 22 nm resolution. Here, we report our recent efforts of designing new plasmonic nanofocusing structures that is capable of achieving optical confinement below 20 nm which can potentially support direct patterning at sub-10nm resolution.
Dynamic Manufacturing Capability Assessment of Industrial Robots Based on Feedback Information in Cloud Manufacturing
Authors: Zhang Zeyu , Xu Wenjun , Liu Quan , Zhou Zude , Pham Duc Truong
Published: July 2017

With the development of information and computer network technology, cloud manufacturing has been developing rapidly, industrial robots (IRs) as a vital symbol and an advanced technology of manufacturing industry, in scheduling service, the constantly changing information data will result in the corresponding vary of the manufacturing capability. Under a fixed constraint of some capability service request, this will decrease the number of the optimal solutions and provide the inaccurate service to users. So it is important to make the manufacturing capability stable and obtain more optimal solutions to satisfy the constraint, thus the dynamic assessment of manufacturing capability based on information feedback is investigated in this paper. A set of indicators is established considering the IRs’ manufacturing capability and a new dynamic assessment model is proposed to achieve the actual data and the expected data information feedback, using the “normal distribution” model, which can correct the assessment weight. By the way, a case study is simulated in the MATLAB, which shows the reliability and reasonability of this method in evaluate the manufacturing capability in IR.
Modeling of the Grinding Wheel Topography Depending on the Recipe-Dependent Volumetric Composition
Authors: Klocke Fritz , Barth Sebastian , Rom Michael , Wrobel Christian
Published: July 2017

The prediction of the grinding process result, such as the workpiece surface quality or the state of the edge zone depending on the used grinding wheel is a great challenge for todays manufacturers and users of grinding tools. This is mainly caused by inadequate predictability of the forces and temperatures acting in the process, which depend on the topography of the grinding wheel coming into contact with the workpiece during the grinding process. The topography of a grinding wheel depends, beside the dressing process, on the structure of the grinding wheel, which is determined by its recipe-dependent volumetric composition. The structure of a grinding tool therefore determines its application behavior strongly. As a result, the knowledge-based prediction of the grinding wheel topography and its influence on the machining behavior is only possible if the recipe-dependent grinding wheel structure is known.

In this paper, an innovative approach for modeling the grinding wheel structure and the resultant grinding wheel topography is discussed. The overall objective of the underlying research project was to create a mathematical-generic grinding wheel model in which the spatial arrangement of the components grains, bond and pores is simulated in a realistic manner starting from the recipe-dependent volumetric composition of a grinding wheel. With this model it is possible to determine the resulting grinding wheel structure and the grinding wheel topography of vitrified and synthetic resin-bonded CBN grinding wheels and thus to predict their application behavior. The originality of the present research results is a generic approach for the modeling of grinding wheels, taking into account the entire grinding wheel structure and build up the topography based on it. Using original mathematical methods, the components of grinding wheels were analyzed and distribution functions of the components were determined. Thus the statistical character of the grinding wheel structure was taken into account. In future, the presented model opens new perspectives in order to optimize and to increase the productivity of grinding processes.
Using Standards in a Competition to Measure and Solve Industrial Robotics Agility Challenges
Authors: Downs Anthony , Harrison William , Schlenoff Craig
Published: July 2017

Researchers at the National Institute of Standards and Technology (NIST) have developed a set of draft standard test methods for measuring and promoting software agility in industrial robots. These test methods are being used as the basis for an upcoming competition called the Agile Robotics for Industrial Applications Competition (ARIAC). ARIAC is being used to promote and push forward the state of the art in software agility and enable technology transfer between academia and industry. This paper describes the background about the test methods, how they were developed, how they will be applied to the ARIAC Competition, and additional information about the ARIAC Competition.
Bingham Fluid-Assisted Fabrication of 3D Vascular-Like Constructs of Interpenetrating Network Hydrogel
Authors: Krishnamoorthy Srikumar , Zhang Mengyun , Song Hongtao , Xu Changxue
Published: July 2017

Organ printing, which utilizes advanced manufacturing technologies to fabricate three-dimensional (3D) functional organs based on layer-by-layer mechanism, is emerging as a promising solution to solve the organ donor shortage problem affecting all over the world. One of the biggest challenges for fabrication of functional and effective thick tissues/organs is the engineering of vascular networks. This paper introduces a Bingham fluid (Carbopol gel) to assist fabrication of 3D vascular-like constructs of interpenetrating network (IPN) hydrogels. Carbopol gel as a Bingham fluid exhibits a characteristic yield stress behavior. As the nozzle moves inside Carbopol, the shear stress is larger than the yield stress and the Carbopol gel behaves like a viscous fluid with a specific viscosity. After the nozzle moves away, the shear stress decreases below the yield stress and the Carbopol gel rapidly solidifies behaving like a solid. This unique rheological property is utilized to support and maintain the shape of the fabricated 3D structures, although the fluid printed is not crosslinked. Finally, the fabricated structures are subject to a two-step gelation process to successfully form 3D vascular-like constructs of IPN hydrogels. This novel approach enables effective and efficient fabrication of complex vascular network of IPN hydrogels.
A Methodology for Predicting Porosity From Thermal Imaging of Melt Pools in Additive Manufacturing Thin Wall Sections
Authors: Khanzadeh Mojtaba , Chowdhury Sudipta , Bian Linkan , Tschopp Mark A.
Published: July 2017

The microstructure and mechanical properties of Laser Based Additive Manufacturing (LBAM) are often inconsistent and unreliable for many industrial applications. One of the key technical challenges is the lack of understanding of the underlying process-structure-property relationship. The objective of the present research is to use the melt pool thermal profile to predict porosity within the LBAM process. Herein, we propose a novel porosity prediction method based on morphological features and the temperature distribution of the top surface of the melt pool as the LBAM part is being built. Self-organizing maps (SOM) are then used to further analyze the 2D melt pool dataset to identify similar and dissimilar melt pools. The performance of the proposed method of porosity prediction uses X-Ray tomography characterization, which identified porosity within the Ti-6Al-4V thin wall specimen. The experimentally identified porosity locations were compared to the porosity locations predicted based on the melt pool analysis. Results show that the proposed method is able to predict the location of porosity almost 85% of the time when the appropriate SOM model is selected. The significance of such a methodology is that this may lead the way towards in situ monitoring and on-the-fly modification of melt pool thermal profile to minimize or eliminate pores within LBAM parts.
Investigation of Porosity and Mechanical Properties of Graphene Nanoplatelets Reinforced AlSi10Mg by Selective Laser Melting
Authors: Wang Yachao , Shi Jing , Lu Shiqiang , Xiao Weihan
Published: July 2017

Graphene possesses many outstanding properties, such as high strengths, light weight, making it an ideal reinforcement for metal matrix composite (MMCs). Meanwhile, fabricating MMCs through laser assisted additive manufacturing (LAAM) has attracted much attention in recent years due to the advantages of low waste, high precision, short production lead time, and high flexibility. In this study, graphene reinforced aluminum alloy AlSi10Mg is fabricated using selective laser melting. Composite powder is prepared using high-energy ball milling. Room temperature tensile tests are conducted to evaluate the tensile properties. Scanning electron microscopy (SEM) observations are conducted to investigate the microstructure and fracture surface of obtain composite. It is found that adding GNPs significantly increases porosity and therefore deteriorates material tensile performance. The relationship between porosity and material strength are numerically investigated. Taking into consideration the strength reduction caused by large porosity, the strengthening effect of GNPs turns out to be significant, which reaches 60.2 MPa.
Framework and Sensitivity Analysis of Joint Energy and Maintenance Planning Considering Production Throughput Requirements
Authors: Dababneh Fadwa , Shah Rahul , Sun Zeyi , Li Lin
Published: July 2017

As the U.S. manufacturing sector becomes more and more competitive, manufactures are seeking to adopt more cost and resource efficient operation practices. Several research studies that optimize production, maintenance, and energy have been conducted. However, research integrating them all in one model is less developed. In this paper, we present a framework on joint maintenance and energy planning while considering production throughput target and buffer constraints. The problem considers a Time-of-Use (TOU) demand response program such that the cost of production, energy, and maintenance is reduced. A sensitivity analysis considering the effect of production system parameters, such as machine rated power, machine production rate, number of maintenance crew resources, etc., on the cost per part is conducted. In addition, the sensitivity due to varying the individual unit costs incurred from production throughput, power demand, and maintenance is investigated. This study can guide manufacturers and researchers in determining the value of using such joint methods. Furthermore, the sensitivity analysis considering joint energy and maintenance can aid manufacturers and researchers in data acquisition so that the most sensitive parameters are given priority, help identify which controllable parameters have the largest impact on the system performance; and determine which parameters are most impactful.
The Effect of Multi-Point Electrical Paths on Global Springback Elimination in Single Point Incremental Forming
Authors: Niebauer Jacklyn , Shaffer Derek , Ragai Ihab , Roth John T.
Published: July 2017

Automotive and aerospace industries are interested in implementing die-less forming processes in order to reduce part costs and the required forming energy. One method of die-less forming is incremental forming, in which a sheet metal part is formed; typically with a hemispherical tool that deforms material as it pushes into the material and passes along the surface to create the desired part geometry. One problem with incremental forming is global springback, which occurs after the part has been formed and is released from the forming fixture. This effect is caused by residual stresses that are created during part deformation and result in geometric inaccuracies after the clamping force has been released. In this paper, the effect of post-deformation applied direct current on the springback of pre-formed sheet metal will be investigated. This is a process is a type of electrically assisted manufacturing (EAM). This paper is a continuation of previous works presented at MSEC 2015–2016. The initial feasibility study described herein already achieves a springback reduction of 26.3% and is dependent on the regions of high stress concentration as well as current density. Future work will extend this reduction through further testing of complex configurations.