bluuebunny/crossref_metadata_2025 huggingface dataset:
Not moving: the fundamental but neglected motor function
Authors: Noorani Imran , Carpenter R. H. S.
Published: February 2017

The function of the motor system in preventing rather than initiating movement is often overlooked. Not only are its highest levels predominantly, and tonically, inhibitory, but in general behaviour it is often intermittent, characterized by relatively short periods of activity separated by longer periods of stillness: for most of the time we are not moving, but stationary. Furthermore, these periods of immobility are not a matter of inhibition and relaxation, but require us to expend almost as much energy as when we move, and they make just as many demands on the central nervous system in controlling their performance. The mechanisms that stop movement and maintain immobility have been a greatly neglected area of the study of the brain. This paper introduces the topics to be examined in this special issue ofPhilosophical Transactions, discussing the various types of stopping and stillness, the problems that they impose on the motor system, the kinds of neural mechanism that underlie them and how they can go wrong.

This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’.
Abandoning and modifying one action plan for alternatives
Authors: Song Joo-Hyun
Published: February 2017

Visual scenes are often complex and crowded with many different objects. To interact effectively, we must choose one object at a time as a goal for action. Certain
external
cues can act as a stop signal, quickly cancelling an ongoing action. Less recognized are
internal
signals. These can come from recent experience, anticipated action outcomes, cognitive states, and when attention is captured by a salient object. These signals elevate one action plan over alternatives and can quickly modify an initial choice. Here, we focus on these internal processes responsible for selecting, abandoning and modifying action plans. We first highlight how the brain resolves competition among multiple action plans. Critical is the existence of parallel motor planning processes, which allow efficient and timely changes. Then, we discuss how the action system interplays with perception, attention and memory processes to bias action selection and suppress or modify erroneous selections. Subsequently, we show how tracking the continuous modification of action trajectories can provide a tool to read out changes in internal cognitive states. Taken together, we shed light on a broader view that sensorimotor networks can continuously modify actions through simultaneous evaluation of alternative activities in concert with widely distributed perceptual and cognitive networks.

This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’.
Behavioural and computational varieties of response inhibition in eye movements
Authors: Cutsuridis Vassilis
Published: February 2017

Response inhibition is the ability to override a planned or an already initiated response. It is the hallmark of executive control as its deficits favour impulsive behaviours, which may be detrimental to an individual's life. This article reviews behavioural and computational guises of response inhibition. It focuses only on inhibition of oculomotor responses. It first reviews behavioural paradigms of response inhibition in eye movement research, namely the countermanding and antisaccade paradigms, both proven to be useful tools for the study of response inhibition in cognitive neuroscience and psychopathology. Then, it briefly reviews the neural mechanisms of response inhibition in these two behavioural paradigms. Computational models that embody a hypothesis and/or a theory of mechanisms underlying performance in both behavioural paradigms as well as provide a critical analysis of strengths and weaknesses of these models are discussed. All models assume the race of decision processes. The decision process in each paradigm that wins the race depends on different mechanisms. It has been shown that response latency is a stochastic process and has been proven to be an important measure of the cognitive control processes involved in response stopping in healthy and patient groups. Then, the inhibitory deficits in different brain diseases are reviewed, including schizophrenia and obsessive-compulsive disorder. Finally, new directions are suggested to improve the performance of models of response inhibition by drawing inspiration from successes of models in other domains.

This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’.
A global perspective on bioinformatics training needs
Authors: Brazas Michelle D. , Brooksbank Cath , Jimenez Rafael C. , Blackford Sarah , Palagi Patricia M , De Las Rivas Javier , Ouellette B.F. Francis , Kumuthini Judit , Korpelainen Eija , Lewitter Fran , van Gelder Celia W.G. , Mulder Nicola , Corpas Manuel , Schneider Maria Victoria , Tan Tin Wee , Clements Dave , Davies Angela , Attwood Teresa K.
Published: February 2017

In the last decade, life-science research has become increasingly data-intensive and computational. Nevertheless, basic bioinformatics and data stewardship are still only rarely taught in life-science degree programmes, creating a widening skills gap that spans educational levels and career roles. To better understand this situation, we ran surveys to determine how the skills dearth is affecting the need for bioinformatics training worldwide. Perhaps unsurprisingly, we found that respondents wanted more short courses to help boost their expertise and confidence in data analysis and interpretation. However, it was evident that most respondents appreciated their need for training only after designing their experiments and collecting their data. This is clearly rather late in the research workflow, and suboptimal from a training perspective, as skills acquired to address a specific need at a particular time are seldom retained, engendering a cycle of low confidence in trainees. To ensure that such skill gaps do not continue to create barriers to the progress of research, we argue that universities should strive to bring their life-science curricula into the digital-data era. Meanwhile, the demand for point-of-need training in bioinformatics and data stewardship will grow. While this situation persists, international groups like GOBLET are increasing their efforts to enlarge the community of trainers and quench the global thirst for bioinformatics training.
ATR inhibition disrupts rewired homologous recombination and fork protection pathways in PARP inhibitor-resistant BRCA-deficient cancer cells
Authors: Yazinski Stephanie A. , Comaills Valentine , Buisson Rémi , Genois Marie-Michelle , Nguyen Hai Dang , Ho Chu Kwen , Todorova Kwan Tanya , Morris Robert , Lauffer Sam , Nussenzweig André , Ramaswamy Sridhar , Benes Cyril H. , Haber Daniel A. , Maheswaran Shyamala , Birrer Michael J. , Zou Lee
Published: February 2017

Poly-(ADP-ribose) polymerase (PARP) inhibitors (PARPis) selectively kill BRCA1/2-deficient cells, but their efficacy in BRCA-deficient patients is limited by drug resistance. Here, we used derived cell lines and cells from patients to investigate how to overcome PARPi resistance. We found that the functions of BRCA1 in homologous recombination (HR) and replication fork protection are sequentially bypassed during the acquisition of PARPi resistance. Despite the lack of BRCA1, PARPi-resistant cells regain RAD51 loading to DNA double-stranded breaks (DSBs) and stalled replication forks, enabling two distinct mechanisms of PARPi resistance. Compared with BRCA1-proficient cells, PARPi-resistant BRCA1-deficient cells are increasingly dependent on ATR for survival. ATR inhibitors (ATRis) disrupt BRCA1-independent RAD51 loading to DSBs and stalled forks in PARPi-resistant BRCA1-deficient cells, overcoming both resistance mechanisms. In tumor cells derived from patients, ATRis also overcome the bypass of BRCA1/2 in fork protection. Thus, ATR inhibition is a unique strategy to overcome the PARPi resistance of BRCA-deficient cancers.
Social media activity in a festival context: temporal and content analysis
Authors: MacKay Kelly , Barbe Danielle , Van Winkle Christine M. , Halpenny Elizabeth
Published: February 2017

Purpose

This study explores the multi-phasic experience of festivals to understand the nature, purpose and degree of social media (SM) use before, during and after festival occurrence and how this may inform better engagement of attendees.

Design/methodology/approach

A census of tweets and posts from four festivals’ Twitter handles and Facebook accounts were coded and analyzed across three time points: one week prior, during and one week after the festival. They were coded on nature (e.g. conversational, promotional, informational), purpose (e.g. information-seeking, friendship/relationship) and presence of links, photos, etc. Tests for platform influences on usage were conducted.

Findings

In total, 1,169 tweets and 483 posts were captured. Two-thirds of SM activity occurred during the festivals, one-third pre-festival and minimal activity post festival. Temporal analyses found that while the purpose and nature of the message content varied across festival time points, this was often dependent on SM platform.

Research limitations/implications

Festivals are not taking advantage of the multi-phase experience model and the utility of SM to maintain contact and encourage visitors to continue processing their experience after the festival. This lost opportunity has implications for re-patronizing behaviour and sponsor relationships.

Originality value

Leung et al. (2013a) call for sector specific research to elucidate SM use in tourism. Festivals provide a unique environment of co-created experience. Findings suggest differential usage of SM across festival time frames and platforms that can be used to guide festival organizations’ SM communication to better engage its patrons.
Can smart homes extend people with Alzheimer’s disease stay at home?
Authors: Brunete González Alberto , Selmes Micheline , Selmes Jacques
Published: February 2017

Purpose

The purpose of this paper is to analyse the needs of people with Alzheimer’s disease and their caregivers in terms of information and communications technology (ICT) and home automation, and how to foster the use of smart devices in their homes and also, to determine whether the use of ICT can extend people with Alzheimer’s disease stay at home in the first stages of the illness, while facilitating their caregivers’ tasks.

Design/methodology/approach

Groups of caregivers, ICT researchers and Alzheimer’s disease experts were gathered to discuss the utility of several solutions. Sessions were grouped into four topics: safety, leisure, activities of daily living and friendly atmosphere. In total, 23 ICT-based solutions to improve life at home of people with Alzheimer’s disease were analysed and grouped under “no interest”, “some interest” and “very interesting”. Caregivers rated these solutions and suggested improvements to them.

Findings

In total, 18 out of 23 proposals were considered “very interesting”, meaning that caregivers considered that they could truly improve the lives of people with Alzheimer’s disease. Caregivers also suggested how to progressively introduce these technical solutions into their homes.

Originality/value

ICT and home automation advances could be very useful if used conveniently. Caregivers consider that smart homes can help people with Alzheimer’s disease in the security, leisure and daily tasks fields, increasing the time they can live alone in their own homes.
Equity incentive and risk taking: evidence from China
Authors: Wang Dong , Wu Desheng
Published: February 2017

Purpose

China has formally implemented equity incentive for more than 10 years; thus, a considerable number of equity incentive programs has entered the exercise period. This means that it is time to conduct a comprehensive analysis of the incentive effects of equity incentive throughout the whole implementation phase. The purpose of this paper is to examine the relationship between equity incentive, enterprise’s risk taking and risk decisions in China.

Design/methodology/approach

Using sensitivity of executives’ wealth and stock price (Delta) to measure the alignment effect and using sensitivity of executives’ wealth and stock return volatility (Vega) to measure the risk-taking effect, this paper aims to empirically test the relation of equity incentive and enterprise’s risk taking and risk decisions.

Findings

The authors find that Vega is positively related to risk taking; however, this improvement was mainly reflected in the private enterprises rather than state-owned enterprises. In terms of corporate policy choice, the authors find that Vega is positively related to firm focus and leverage. But, they have not found that Vega can promote R&D investment.

Originality/value

Existing studies have mostly concerned about the executives’ opportunistic behavior; however, analyses of the positive effect of equity incentive are limited. The authors use a combination of risk-taking incentives and alignment incentives to test the relationship between equity incentive and risk taking.
Land and resources acquisition, equity investment increase and enterprise overinvestment
Authors: Yang Jinyu , Liu Bin , Yuan Lihua
Published: February 2017

Purpose

This paper comes to the point from the tax competition of local government in investment promotion and capital introduction. This paper aims to empirically examine the internal mechanism of enterprises obtaining land resources from local government and its resulting equity investment increase and economic consequences of overinvestment.

Design/methodology/approach

The data of China’s A-share listed companies from 2007 to 2014 were used to test the relationship between the increase in enterprise equity investment and the acquisition of land resources and overinvestment. The descriptive statistics, correlation analysis and least squares linear regression were used to solve the above question.

Findings

One of the reasons for the enterprise equity increase is to obtain scarce land resources. The enterprise acquisition for land resources leads to overinvestment. The equity investment increase from obtaining land resources will further stimulate enterprise group to overinvest.

Research limitations/implications

The authors could not get the actual data of land that subsidiaries have obtained directly. In this research, the authors get the data using consolidated statements and subsidiary statements indirectly.

Practical implications

The results make contributions to the influencing factors and economic consequence of the enterprise investment structural deviation.

Social implications

It provides reference to optimize the “interaction” relationship between government and enterprises.

Originality/value

It identified the “dual-channel” conduction mechanism between land resource acquisition and enterprise overinvestment.
The effects of placement on dementia care recipients’ and family caregivers’ quality of life: a literature review
Authors: Moon Heehyul , Dilworth-Anderson Peggye , Gräske Johannes
Published: February 2017

Purpose

The purpose of this paper is to review and synthesize the research literature on the quality of life (QoL) of both caregivers (CGs) and care recipients (CRs) with dementia after admission to long-term care facilities.

Design/methodology/approach

Four databases – AgeLine, Medline, EBSCO, and PyscINFO – were searched and the relevant literature from 2002 onwards was reviewed.

Findings

The review of 12 studies (five studies, including only family CGs; six studies including residents; one study including both family CGs and CRs) reveals a discrepancy regarding the effects of institutionalization on the CRs’ and CGs’ QoL. Among seven studies on CRs’ QoL change, some reviewed studies found a significant decline in CRs’ QoL after placement with others showing that CRs’ QoL was improved or stable. While some reports indicated that some family CGs benefited from placement, others showed that CGs merely maintained their QoL. However, family CGs in the reviewed studies were more likely to report improved QoL than were their CRs after institutionalization.

Research limitations/implications

The authors recommend that future studies should focus on understanding the individual’s adaptation to placement, dyadic changes in QoL (including mediators/moderators). They emphasize the need for a comprehensive longitudinal study with more than one wave and includes diverse groups including racial/ethnic minority CGs and CRs.

Originality/value

This study reviewed and synthesized the research literature on the QoL of both caregiver and the people with dementia they cared for after those they cared for were admitted to long-term care facilities. The conclusions drawn about influences on QoL provide guidance for identifying best practices and research.
Improving the learning and developmental potential of SWOT analysis: introducing the LISA framework
Authors: Pandya Saurabh
Published: February 2017

Purpose

This paper aims to provide a framework which can help to improve the learning and developmental potential of the popular SWOT analysis and make it more effective.

Design/methodology/approach

The paper conceptualizes the LISA framework where L, I, S and A correspond to S, W, O and T, respectively, of the traditional SWOT analysis framework. Each linkage is discussed to provide some insights as to how the understanding of the SWOT analysis can be further extended to improve its learning potential and effectiveness.

Findings

The Strengths identified through the SWOT analysis should be “Leveraged”, the Weaknesses should be “Improved upon”, the Opportunities need to be “Seized” and, finally, the Threats can be mitigated if there is “Awareness” about the same. Thus, the LISA framework, i.e. leveraging the strengths, improving upon the weaknesses, seizing the opportunities and being aware about the threats, can help an organization gain more out of its SWOT analysis exercise.

Practical implications

By applying the LISA framework to the SWOT analysis undertaken at various levels, an organization can improve the learning outcomes for its employees as well as top executives. Quite often, SWOT analysis is performed at an individual and the group level, and hence the linkages discussed in the LISA framework here can be useful to individuals as well as groups (teams). They can take their development to the next level.

Originality/value

The LISA framework provides a more refined approach, as well as new linkages, to improve and increase the utility of the standard SWOT analysis framework.
The strategic Chief Information Officer
Authors: Toor Tajinder
Published: February 2017

Purpose

This paper aims to discuss how Chief Information Officers (CIOs) can be the catalysts of change and play an influential role in pushing strategic transformations in their organizations.

Design/methodology/approach

This paper is a strategy framework pyramid with the mapped CIO’s responsibilities suggesting CIOs to move up the pyramid by spending more time in strategy analysis and development to gain the strong strategic alignment with the business.

Findings

CIOs need to prioritize the strategic elements of their role and build strong relationships with the front of the business to analyze and develop the organization strategy.

Originality/value

The paper provides valuable information in a very concise and easy-to-understand format, thus saving executives hours of browsing and reading time.
Geopolitics: a new field of expertise for buyers
Authors: Poissonnier Hugues
Published: February 2017

Purpose

This paper aims to show the interest of using geopolitical analysis for buyers.

Design/methodology/approach

This study is a historical approach.

Findings

Geopolitics is very useful for buyers to develop new skills among their suppliers.

Originality/value

This paper shows that evolutions of the macro environment are more and more impactful for companies. Taking geopolitical considerations into account is a new key of relevance for purchasing decisions.
Supply resource management: Salomon and his network of subcontractors in Romania
Authors: Calvi Richard
Published: February 2017

Purpose

According to Christopher (2000), in a lot of sectors, the competition is a question of supply chain against supply chain. The winner in term of competitive advantage should be the one, who is able to obtain more than the competitor from the available resources. In strategic literature, Dyer and Singh (1998) are the first who introduced the concept of “relational competency” to explain why some companies gain their competitive advantage not directly from their internal resources but mainly because they are able better to combine external resources.

Design/methodology/approach

This paper is a case study.

Findings

The author describes the different phases and strategic decisions in the building of a real supplier eco-system.

Research limitations/implications

It is a sole case study.

Practical implications

This study is a description of a success story.

Originality/value

This study is a description of an external resource management in action.
Targeted ultrasound of the liver: Impact on scanning time of a new approach in chronic liver disease
Authors: Harris Nicole , Gorelik Alexandra , Gibson Robert N
Published: February 2017

Introduction

Targeted ultrasound of the liver (TUSL) has been proposed as a new approach in chronic liver disease to meet the increasing demands on ultrasound services in this patient population. This study analyses the impact of TUSL on examination time.

Methods

Retrospective cohort analysis of time taken to perform liver ultrasound on consecutive chronic liver disease patients pre‐ (n = 230) and post‐ (n = 147) introduction of TUSL. Within each cohort, patients were subdivided into three categories based on the clinical indication: Group 1. hepatocellular carcinoma (HCC) surveillance; Group 2. detection of cirrhosis, fibrosis or fatty liver; Group 3. detection of portal hypertension. The primary outcome was difference in examination time in the pre‐ and post‐intervention groups.

Results

Introduction of TUSL led to 49% reduction in examination time (median (Q1–Q3) 23.7 (16.7–36.2) min in pre‐TUSL period vs 12.1 (6.4–19.5) min in post, P < 0.001) and it was consistent across all three clinical indication groups (gr1: median 23.1 minutes vs 8.1 minutes (P < 0.001), gr2: 23.0 minutes vs 14.3 minutes (P < 0.001), gr3: 32.2 minutes vs 15.3 minutes (P = 0.006)). After the adjustment for clinical indication and sonographer's experience, impact of TUSL on time reduction remained significant with a 66.6% time reduction (95% CI 53.6 to 79.5).

Conclusion

Targeted ultrasound of the liver improves efficiency of chronic liver disease ultrasound with halving of examination times and consequently has the potential to greatly improve resource utilization.
Are Related Party Transactions Red Flags?
Authors: Kohlbeck Mark , Mayhew Brian W.
Published: February 2017

This study investigates whether or not related party transactions serve as “red flags” that warn of potential financial misstatement. We hand‐collect related party transactions for S&P 1500 firms in 2001, 2004, and 2007 and find a positive correlation between these transactions and future restatements, suggesting restatements are more likely when a firm engages in related party transactions. The association is concentrated among transactions that appear to reflect “tone at the top” rather than arguably more necessary business transactions. We also find RPT firms pay lower audit fees. However, “tone RPT” firms that subsequently restate pay higher audit fees, providing evidence that auditors recognize the individual restatement risks of these firms. Our results suggest that tone‐based RPTs serve as signals of higher risk of material misstatement.
Is long‐term protection useful for the regeneration of disturbed plant communities in dry areas?
Authors: Tarhouni Mohamed , Ben Hmida Walid , Ouled Belgacem Azaiez , Louhaichi Mounir , Neffati Mohamed
Published: February 2017

In dry areas, natural plant communities are mainly affected by climatic stress and human disturbances – overgrazing, ploughing and biomass harvesting – that accelerate their degradation. Management techniques, including creation of national parks (fencing), are needed to conserve natural resources/biodiversity. The long‐term effects of protection on the plant communities should be monitored. This study assessed the results of long‐term protection on the composition and diversity of the natural plant communities of Sidi Toui National Park (southern Tunisia) using the point‐quadrat method and ecological indicators of the ecosystem structure. Comparison of these indicators for the period 1990–2011 inside (fenced) and outside (disturbed) the Park showed that regeneration of natural vegetation increased during the first decade of the fencing period (1990–2001), but declined during the period (2008–2011). After a long period of fencing, plant tufts were bigger and aged, and the ecosystem dynamics decreased. In the absence of animal activities, the hardpan at the soil surface impedes seedling emergence. This suggests that long‐term fencing is not recommended for conserving floral diversity in dryland ecosystems. To ensure and maintain the regeneration of these ecosystems, fencing periods alternating with controlled grazing (by introducing wild herbivores) are recommended.
The Choice of Euthanasia Method Affects Metabolic Serum Biomarkers
Authors: Pierozan Paula , Jernerén Fredrik , Ransome Yusuf , Karlsson Oskar
Published: February 2017

The impact of euthanasia methods on endocrine and metabolic parameters in rodent tissues and biological fluids is highly relevant for the accuracy and reliability of the data collected. However, few studies concerning this issue are found in the literature. We compared the effects of three euthanasia methods currently used in animal experimentation (i.e. decapitation, CO2 inhalation and pentobarbital injection) on the serum levels of corticosterone, insulin, glucose, triglycerides, cholesterol and a range of free fatty acids in rats. The corticosterone and insulin levels were not significantly affected by the euthanasia protocol used. However, euthanasia by an overdose of pentobarbital (120 mg/kg intraperitoneal injection) increased the serum levels of glucose, and decreased cholesterol, stearic and arachidonic acids levels compared with euthanasia by CO2 inhalation and decapitation. CO2 inhalation appears to increase the serum levels of triglycerides, while euthanasia by decapitation induced no individual discrepant biomarker level. We conclude that choice of the euthanasia methods is critical for the reliability of serum biomarkers and indicate the importance of selecting adequate euthanasia methods for metabolic analysis in rodents. Decapitation without anaesthesia may be the most adequate method of euthanasia when taking both animal welfare and data quality in consideration.
Social Spillovers in the Classroom: Identification, Estimation and Policy Analysis
Authors: Pereda‐Fernández Santiago
Published: February 2017

I present a method to jointly estimate social spillovers in the classroom and the distributions of teacher and student effects. This method is based on the covariance and higher‐order moments restrictions of the test scores, requiring the random assignment of teachers and students to classrooms. Using the Tennessee Project STAR dataset, I estimate sizeable spillovers in kindergarten classrooms and departures from normality of the teacher and student ability distributions. The estimates also show that reducing class size has a positive effect on mean performance, but it increases the inequality. Based on these estimates, I perform several input‐neutral policy counterfactuals involving teachers and students assignment rules, and changing the distribution of class sizes. For the latter, I derive an optimal class size distribution rule, which increases mean test scores and reduces the overall variance.
Triple‐reassortant influenza A virus with H3 of human seasonal origin, NA of swine origin, and internal A(H1N1) pandemic 2009 genes is established in Danish pigs
Authors: Krog Jesper Schak , Hjulsager Charlotte Kristiane , Larsen Michael Albin , Larsen Lars Erik
Published: February 2017

This report describes a triple‐reassortant influenza A virus with a HA that resembles H3 of human seasonal influenza from 2004 to 2005, N2 from influenza A virus already established in swine, and the internal gene cassette from A(H1N1)pdm09 has spread in Danish pig herds. The virus has been detected in several Danish pig herds during the last 2‐3 years and may possess a challenge for human as well as animal health.
Near white light emission of Ce3+‐, Ho3+‐, and Sm3+‐doped oxyfluoride silicate glasses
Authors: Zhou Yao , Zhu Chaofeng , Yang Xuena
Published: February 2017

The Ce3+‐, Ho3+‐, and Sm3+‐ single and co‐doped oxyfluoride silicate glasses for light emitting diodes are studied. These glasses were prepared by melt quenching method and their optical and structural properties were investigated by absorption spectra, photoluminescence spectra, Commission International de I'Eclairage chromaticity coordinates, X‐ray diffraction, and Fourier transform infrared spectra. It is found that the introduction of Al2O3 in glass composition can improve the emissions of Ho3+ and Sm3+. While the presence of B2O3 has the adverse effect and can suppress the emissions of Ho3+ and Sm3+. With substituting Na2O for CaO in the glass compositions, CaF2 crystals can be formed during the melt quenching process. We find the formation of CaF2 crystals can change the emission behavior of Ho3+ and Sm3+ ions. White light emissions can be achieved in the glasses and the luminescence colors can be tuned by varying the concentrations of the doped rare‐earth ions and the composition of glass matrix. The Ce3+‐, Ho3+‐, and Sm3+‐doped oxyfluoride silicate glasses presented here demonstrate promising applications in the fields of light emitting diodes.
Activation of Wnt/β‐catenin signalling is required for TGF‐β/Smad2/3 signalling during myofibroblast proliferation
Authors: Xu Liang , Cui Wen‐Hui , Zhou Wen‐Cheng , Li De‐Lin , Li Liu‐Cheng , Zhao Ping , Mo Xiao‐Ting , Zhang Zhihui , Gao Jian
Published: February 2017

Fibrosis in animal models and human diseases is associated with aberrant activation of the Wnt/β‐catenin pathway. Despite extensive research efforts, effective therapies are still not available. Myofibroblasts are major effectors, responsible for extracellular matrix deposition. Inhibiting the proliferation of the myofibroblast is crucial for treatment of fibrosis. Proliferation of myofibroblasts can have many triggering effects that result in fibrosis. In recent years, the Wnt pathway has been studied as an underlying factor as a primary contributor to fibrotic diseases. These efforts notwithstanding, the specific mechanisms by which Wnt‐mediated promotes fibrosis reaction remain obscure. The central role of the transforming growth factor‐β (TGF‐β) and myofibroblast activity in the pathogenesis of fibrosis has become generally accepted. The details of interaction between these two processes are not obvious. The present investigation was conducted to evaluate the level of sustained expression of fibrosis iconic proteins (vimentin, α‐SMA and collagen I) and the TGF‐β signalling pathway that include smad2/3 and its phosphorylated form p‐smad2/3. Detailed analysis of the possible molecular mechanisms mediated by β‐catenin revealed epithelial–mesenchymal transition and additionally demonstrated transitions of fibroblasts to myofibroblast cell forms, along with increased activity of β‐catenin in regulation of the signalling network, which acts to counteract autocrine TGF‐β/smad2/3 signalling. A major outcome of this study is improved insight into the mechanisms by which epithelial and mesenchymal cells activated by TGFβ1‐smad2/3 signalling through Wnt/β‐catenin contribute to lung fibrosis.
Trade‐off relationship between productivity and thallus toughness in Laminariales (Phaeophyceae)
Authors: Sakanishi Yoshihiko , Kasai Hiromi , Tanaka Jiro
Published: February 2017

Trade‐off relationships are considered key to understanding the mechanisms supporting the coexistence of multiple species within kelp beds. Thus, information on trade‐offs is expected to contribute to conservation of kelp bed diversity. To test the existence of a trade‐off between productivity and thallus toughness, thallus traits and relationships between the traits were examined for seven species of Laminariales including 24 populations. For each population, photosynthetic capacity per unit biomass (as A
mass) and nitrogen (i.e., photosynthetic nitrogen‐use efficiency, PNUE), nitrogen content (as N
mass), thallus mass per unit thallus area (as TMA) and force required to penetrate the thallus (as F
p, a common index of leaf toughness in land plants by punch test) were determined. A
mass increased with increasing N
mass. Blades with high N
mass showed high A
mass. These blades may invest a large proportion of nitrogen to the photosynthetic parts, and consequently exhibit high metabolic rates. Moreover, blades with high N
mass tended to be associated with low TMA, and N
mass decreased with increasing TMA. A significant negative correlation was observed between TMA and A
mass because of the linkage of high A
mass with high N
mass and high N
mass associated with low TMA, while a significant positive correlation was observed between TMA and F
p. The two correlations indicate the existence of a trade‐off between productivity and thallus toughness in Laminariales. PNUE showed a significant negative correlation with TMA, which also showed a significant positive correlation with F
p as the index of thallus toughness, and therefore a trade‐off relationship between productivity and thallus toughness.
Model (At Least) Twice, Build Once: Experiences With the Design–Bid–Build Process for Solar Photovoltaic Arrays
Authors: Dougherty Brian , Boyd Matthew
Published: February 2017

Commercial-scale solar photovoltaic (PV) arrays were designed, constructed, and are now operational on the Gaithersburg, Maryland campus of the National Institute of Standards and Technology (NIST). A design–bid–build process was followed where the contractors used photovoltaic system modeling tools both during the initial design phase and during the postbid, prebuild phase. To help investigate the specific aspects of the contractors' evolving designs, the authors conducted their own independent photovoltaic system modeling. This independent modeling helped identify design elements that could be improved and so aided efforts to maximize the annual renewable energy generation. An estimated 2.5% gain in annual energy generation is being realized as a result of this independent modeling effort. To provide context for the modeling work and the lessons learned, key events impacting the design–bid–build process are described. The installed systems are summarized and also contrasted with the proposed designs. The power generation at three sites are compared over two different 12-month intervals.
A Novel Numerical Approach for Convective and Radiative Heat Transfer Analysis of Fluid Flow Problems Within Triangular Cavities Using Natural Element Method
Authors: Moftakhari Ardeshir , Aghanajafi Cyrus , Ghazvin Ardalan Moftakhari Chaei
Published: February 2017

Thermal analysis of fluid flow is always regarded as an important research issue within cavities in order to become familiar with the characteristics of fluid flow phenomenon in enclosures. This research paper investigates the fluid and heat transfer analysis of fluid flow inside a triangular cavity using natural element methodology (NEM). This Galerkin-based methodology has been introduced for a decade and almost demonstrated its efficiency in the numerical heat transfer analysis of problems in most engineering sciences. The fluid flow contains natural convection along with conduction and radiation heat transfer with medium's walls, which have absorbing, emitting, semitransparent, and nonscattering characteristics. The final results investigate the effects of radiative and natural convection heat transfer on the fluid flow pattern as expressed in Rayleigh number, stream function, strength of natural convection regime, etc., which are checked with other similar studies presented in the literature and shows how promising NEM can be as an efficient numerical approach to improve computational precision when dealing with fluid mechanic problems.
Characterization of a 0.35T MR system for phantom image quality stability and in vivo assessment of motion quantification
Authors: Saenz Daniel L. , Yan Yue , Christensen Neil , Henzler Margaret A. , Forrest Lisa J. , Bayouth John E. , Paliwal Bhudatt R.
Published: February 2017

ViewRay is a novel MR‐guided radiotherapy system capable of imaging in near real‐time at four frames per second during treatment using 0.35T field strength. It allows for improved gating techniques and adaptive radiotherapy. Three cobalt‐60 sources ( Curies) permit multiple‐beam, intensity‐modulated radiation therapy. The primary aim of this study is to assess the imaging stability, accuracy, and automatic segmentation algorithm capability to track motion in simulated and in vivo targets. Magnetic resonance imaging (MRI) characteristics of the system were assessed using the American College of Radiology (ACR)‐recommended phantom and accreditation protocol. Images of the ACR phantom were acquired using a head coil following the ACR scanning instructions. ACR recommended T1‐ and T2‐weighted sequences were evaluated. Nine measurements were performed over a period of seven months, on just over a monthly basis, to establish consistency. A silicon dielectric gel target was attached to the motor via a rod. 40 mm total amplitude was used with cycles of 3 to 9 s in length in a sinusoidal trajectory. Trajectories of six moving clinical targets in four canine patients were quantified and tracked. ACR phantom images were analyzed, and the results were compared with the ACR acceptance levels. Measured slice thickness accuracies were within the acceptance limits. In the 0.35 T system, the image intensity uniformity was also within the ACR acceptance limit. Over the range of cycle lengths, representing a wide range of breathing rates in patients imaged at four frames/s, excellent agreement was observed between the expected and measured target trajectories. In vivo canine targets, including the gross target volume (GTV), as well as other abdominal soft tissue structures, were visualized with inherent MR contrast, allowing for preliminary results of target tracking.

PACS number: 87.61.Tg
Patient dose measurement in common medical X‐ray examinations in Iran
Authors: Rasuli Behrouz , Mahmoud‐Pashazadeh Ali , Ghorbani Mohammad , Juybari Raheleh Tabari , Naserpour Mozafar
Published: February 2017

The main purpose of this study was to investigate patient dose in the chest (PA/AP/LAT) and skull (PA/AP/LAT) X‐ray examinations, as frequent procedures. The study was performed in eight public hospitals of Khuzestan province, Iran. Patient dosimetry was conducted on 567 standard patient X‐ray examinations (males: 61.2%, female: 38.2%). Dosimetry protocol in this study was indirect method, according to the International Atomic Energy Agency (IAEA) Technical Reports series No. 457. Patients weighing were considered as standard. In the indirect dosimetry approach, exposure parameters such as kVp, mAs, focal film distance (FFD), and tube outputs recorded during data acquisition were used for calculating incident air kerma on the patient's skin, entrance surface air kerma (ESAK) that is recommended by the IAEA as the most appropriate patient dosimetry quantity in simple radiographic examinations. This survey reveals significant variations in the radiological practice. Results showed that the parameters set by radiologic technologists change in a wide range: mAs varied from 2 to 80 for skull PA, 2 to 202 for chest LAT, and FFD varied from 50 to 180 for skull LAT projection. The study showed that patient doses in three chest projections exceed the IAEA and European Commission dose reference levels (EC DRLs) — 1.0, 1.12, and 2.20 mGy for chest PA, chest AP, and chest LAT, respectively. Results also showed that mean ESAKs of patients in skull projections were generally lower than the IAEA and EC DRLs, 1.5, 1.72, and 2.25 for skull LAT, skull AP, and skull PA, respectively. This study provides evidence that dose reduction in the simple X‐ray examinations is feasible by updating clinical audits and implementation of systematic quality assurance (QA) and quality control (QC) programs. The authors recommend that DRLs obtained in this study can be used as local DRLs in Khuzestan area and dose surveys must be performed in all provinces to establish national dose reference levels (NDRLs) in Iran.

PACS numbers: 87.53.Bn, 87.57.uq, 87.59.B
Evaluation of lens dose from anterior electron beams: comparison of Pinnacle and Gafchromic EBT3 film
Authors: Sonier Marcus , Wronski Matt , Yeboah Collins
Published: February 2017

Lens dose is a concern during the treatment of facial lesions with anterior electron beams. Lead shielding is routinely employed to reduce lens dose and minimize late complications. The purpose of this work is twofold: 1) to measure dose profiles under large‐area lead shielding at the lens depth for clinical electron energies via film dosimetry; and 2) to assess the accuracy of the Pinnacle treatment planning system in calculating doses under lead shields. First, to simulate the clinical geometry, EBT3 film and 4 cm wide lead shields were incorporated into a Solid Water phantom. With the lead shield inside the phantom, the film was positioned at a depth of 0.7 cm below the lead, while a variable thickness of solid water, simulating bolus, was placed on top. This geometry was reproduced in Pinnacle to calculate dose profiles using the pencil beam electron algorithm. The measured and calculated dose profiles were normalized to the central‐axis dose maximum in a homogeneous phantom with no lead shielding. The resulting measured profiles, functions of bolus thickness and incident electron energy, can be used to estimate the lens dose under various clinical scenarios. These profiles showed a minimum lead margin of 0.5 cm beyond the lens boundary is required to shield the lens to of the dose maximum. Comparisons with Pinnacle showed a consistent overestimation of dose under the lead shield with discrepancies of occurring near the shield edge. This discrepancy was found to increase with electron energy and bolus thickness and decrease with distance from the lead edge. Thus, the Pinnacle electron algorithm is not recommended for estimating lens dose in this situation. The film measurements, however, allow for a reasonable estimate of lens dose from electron beams and for clinicians to assess the lead margin required to reduce the lens dose to an acceptable level.

PACS number(s): 87.53.Bn, 87.53.Kn, 87.55.‐x, 87.55.D‐
Quantitative outcome of registration methods for correcting cardiac drift in cardiac PET/CT imaging
Authors: Nye Jonathon A. , Tudorascu Dana , Esteves Fabio , Votaw John R.
Published: February 2017

Myocardial perfusion studies suffer from artifacts caused by misalignment of the transmission and emission data due to the influences of voluntary and involuntary patient motion. Regardless of or respiratory‐averaged CT based attenuation correction and good patient cooperation, approximately 21% of perfusion studies exhibit artifacts arising from misalignment that cannot be corrected by manipulating the attenuation acquisition protocol. This misalignment, termed cardiac drift, is caused by slow‐moving abdominal cavity contents that reposition the heart in the thorax and appear as myocardial uptake overlying the left CT lung in fused PET/CT images. This study evaluates three postimaging registration techniques to correct PET/CT misalignment by altering the transmission map to match myocardial uptake. Simulated misalignment studies were performed with a cardiac torso phantom filled with []FDG at 10:1 myocardium/background. An air‐filled saline bag affixed to the medial left lung surface served as a distensible lung. An initial CT acquisition was followed by successive PET acquisitions consisting of small displacements of the cardiac insert into the left lung. Phantom transmission scans were aligned to the myocardial uptake in the emission scans by applying 1) full rigid‐body translations and rotations, 2) rigid‐body restricted to medial / lateral and superior / inferior translation, or 3) an emission‐driven method that adds myocardial tissue to the transmission scan. These methods were also applied to 10 low‐likelihood coronary artery disease (CAD) patients showing signs of cardiac drift. Full rigid‐body registration showed significant over‐correction () of activity concentrations in the artifact areas of the phantom data due the relocation of highly attenuating structures (i.e., spine). Inaccurate regional activity distributions were also observed as streaks extending from the spine and these results were replicated in the patient population. There was no significant difference between the true phantom activity concentration after correction with the emission‐driven method. Misalignment corrected with the rigid‐body registration results in an increase in activity concentration but fails to accurately recover the true concentration. These data suggest that a nonlinear image registration approach such as an emission‐driven method results in a more uniform activity distribution throughout the myocardium, and is more appropriate for addressing the cardiac drift misalignment problem.

PACS number(s): 87.57.uk, 87.57.Q, 87.57.nj, 87.57.C, 87.19.Hh
The suitability of common metrics for assessing parotid and larynx autosegmentation accuracy
Authors: Beasley William J. , McWilliam Alan , Aitkenhead Adam , Mackay Ranald I. , Rowbottom Carl G.
Published: February 2017

Contouring structures in the head and neck is time‐consuming, and automatic segmentation is an important part of an adaptive radiotherapy workflow. Geometric accuracy of automatic segmentation algorithms has been widely reported, but there is no consensus as to which metrics provide clinically meaningful results. This study investigated whether geometric accuracy (as quantified by several commonly used metrics) was associated with dosimetric differences for the parotid and larynx, comparing automatically generated contours against manually drawn ground truth contours. This enabled the suitability of different commonly used metrics to be assessed for measuring automatic segmentation accuracy of the parotid and larynx. Parotid and larynx structures for 10 head and neck patients were outlined by five clinicians to create ground truth structures. An automatic segmentation algorithm was used to create automatically generated normal structures, which were then used to create volumetric‐modulated arc therapy plans. The mean doses to the automatically generated structures were compared with those of the corresponding ground truth structures, and the relative difference in mean dose was calculated for each structure. It was found that this difference did not correlate with the geometric accuracy provided by several metrics, notably the Dice similarity coefficient, which is a commonly used measure of spatial overlap. Surface‐based metrics provided stronger correlation and are, therefore, more suitable for assessing automatic segmentation of the parotid and larynx.

PACS number(s): 87.57.nm, 87.55.D, 87.55.Qr