Quantitative Input Research Articles

TH-A-207B-02: QIBA Ultrasound Elasticity Imaging System Biomarker Qualification and User Testing of Systems

Imaging of tissue elastic properties is a relatively new and powerful approach to one of the oldest and most important diagnostic tools. Imaging of shear wave speed with ultrasound is has been added to most high-end ultrasound systems. Understanding this exciting imaging mode aiding its most effective use in medicine can be a rewarding effort for medical physicists and other medical imaging and treatment professionals. Assuring consistent, quantitative measurements across the many ultrasound systems in a typical imaging department will constitute a major step toward realizing the great potential of this technique and other quantitative imaging. This session will target these two goals with two presentations. A. Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity - Shigao Chen, Ph.D. Learning objectives-To understand: 1. Introduction: • Importance of tissue elasticity measurement • Strain vs. shear wave elastography (SWE), beneficial features of SWE • The link between shear wave speed and material properties, influence of viscosity 2. Generation of shear waves • External vibration (Fibroscan) • ultrasound radiation force • Point push • Supersonic push (Aixplorer) • Comb push (GE Logiq E9) 3. Detection of shear waves • Motion detection from pulse-echo ultrasound • Importance of frame rate for shear wave imaging • Plane wave imaging detection • How to achieve high effective frame rate using line-by-line scanners 4. Shear wave speed calculation • Time to peak • Random sample consensus (RANSAC) • Cross correlation 5. Sources of bias and variation in SWE • Tissue viscosity • Transducer compression or internal pressure of organ • Reflection of shear waves at boundaries B. Elasticity Imaging System Biomarker Qualification and User Testing of Systems – Brian Garra, M.D. Learning objectives-To understand: 1. Goals • Review the need for quantitative medical imaging • Provide examples of quantitative imaging biomarkers • Acquaint the participant with the purpose of the RSNA Quantitative Imaging Biomarker Alliance and the need for such an organization • Review the QIBA process for creating a quantitative biomarker • Summarize steps needed to verify adherence of site, operators, and imaging systems to a QIBA profile 2. Underlying Premise and Assumptions • Objective, quantifiable results are needed to enhance the value of diagnostic imaging in clinical practice • Reasons for quantification i. Evidence based medicine requires objective, not subjective observer data ii. Computerized decision support tools (eg CAD) generally require quantitative input. iii. Quantitative, reproducible measures are more easily used to develop personalized molecular medical diagnostic and treatment systems 3. What is quantitative imaging? • Definition from Imaging Metrology Workshop 4. The Quantitative Imaging Biomarker Alliance • Formation 2008 • Mission • Structure • Example Imaging Biomarkers Being Explored • Biomarker Selection • Groundwork • Draft Protocol for imaging and data evaluation • QIBA Profile Drafting • Equipment and Site Validation i. Technical ii. Clinical • Site and Equipment QA and Compliance Checking 5. Ultrasound Elasticity Estimation Biomarker • US Elasticity Estimation Background • Current Status and Problems • Biomarker Selection-process and outcome 6. US SWS for Liver Fibrosis Biomarker Work • Groundwork i. Literature search and analysis results ii. Phase I phantom testing-Elastic phantoms iii. Phase II phantom testing-Viscoelastic phantoms iv. Digital Simulated Data • Protocol and Profile Drafting i Protocol: based on UPICT and existing literature and standards bodies protocols ii. Profile-Current claims, Manufacturer specific appendices 7. What comes after the profile • Profile Validation i Technical validation ii. Clinical validation • QA and Compliance i. Possible approaches 1. Site a. Operator testing b. Site protocol re-evaluation 2. Imaging system a. Manufacturer testing and attestation b. User acceptance testing and periodic QA i. Phantom Tests ii. Digital Phantom Based Testing iii. Standard QA Testing iv. Remediation Schemes 8. Profile Evolution • Towards additional applications • Towards higher accuracy and precision Supported in part by NIH contract HHSN268201300071C from NIBIB. Collaboration with GE Global Research, no personal support.; S. Chen, Some technologies described in this presentation have been licensed. Mayo Clinic and Dr. Chen have financial interests these technologies.

TH-A-207B-00: Shear-Wave Imaging and a QIBA US Biomarker Update

Imaging of tissue elastic properties is a relatively new and powerful approach to one of the oldest and most important diagnostic tools. Imaging of shear wave speed with ultrasound is has been added to most high-end ultrasound systems. Understanding this exciting imaging mode aiding its most effective use in medicine can be a rewarding effort for medical physicists and other medical imaging and treatment professionals. Assuring consistent, quantitative measurements across the many ultrasound systems in a typical imaging department will constitute a major step toward realizing the great potential of this technique and other quantitative imaging. This session will target these two goals with two presentations. A. Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity - Shigao Chen, Ph.D. Learning objectives-To understand: 1.Introduction: •Importance of tissue elasticity measurement •Strain vs. shear wave elastography (SWE), beneficial features of SWE •The link between shear wave speed and material properties, influence of viscosity 2.Generation of shear waves •External vibration (Fibroscan) •ultrasound radiation force •Point push •Supersonic push (Aixplorer) •Comb push (GE Logiq E9) 3.Detection of shear waves •Motion detection from pulse-echo ultrasound •Importance of frame rate for shear wave imaging •Plane wave imaging detection •How to achieve high effective frame rate using line-by-line scanners 4.Shear wave speed calculation •Time to peak •Random sample consensus (RANSAC) •Cross correlation 5.Sources of bias and variation in SWE •Tissue viscosity •Transducer compression or internal pressure of organ •Reflection of shear waves at boundaries B. Elasticity Imaging System Biomarker Qualification and User Testing of Systems – Brian Garra, M.D. Learning objectives-To understand: 1.Goals •Review the need for quantitative medical imaging •Provide examples of quantitative imaging biomarkers •Acquaint the participant with the purpose of the RSNA Quantitative Imaging Biomarker Alliance and the need for such an organization •Review the QIBA process for creating a quantitative biomarker •Summarize steps needed to verify adherence of site, operators, and imaging systems to a QIBA profile 2.Underlying Premise and Assumptions •Objective, quantifiable results are needed to enhance the value of diagnostic imaging in clinical practice •Reasons for quantification i.Evidence based medicine requires objective, not subjective observer data ii.Computerized decision support tools (eg CAD) generally require quantitative input. iii.Quantitative, reproducible measures are more easily used to develop personalized molecular medical diagnostic and treatment systems 3.What is quantitative imaging? •Definition from Imaging Metrology Workshop 4.The Quantitative Imaging Biomarker Alliance •Formation 2008 •Mission •Structure •Example Imaging Biomarkers Being Explored •Biomarker Selection •Groundwork •Draft Protocol for imaging and data evaluation •QIBA Profile Drafting •Equipment and Site Validation i.Technical ii.Clinical •Site and Equipment QA and Compliance Checking 5.Ultrasound Elasticity Estimation Biomarker •US Elasticity Estimation Background •Current Status and Problems •Biomarker Selection-process and outcome 6.US SWS for Liver Fibrosis Biomarker Work •Groundwork i.Literature search and analysis results ii.Phase I phantom testing-Elastic phantoms iii.Phase II phantom testing-Viscoelastic phantoms iv.Digital Simulated Data •Protocol and Profile Drafting iProtocol: based on UPICT and existing literature and standards bodies protocols ii.Profile-Current claims, Manufacturer specific appendices 7.What comes after the profile •Profile Validation iTechnical validation ii.Clinical validation •QA and Compliance i.Possible approaches 1.Site a.Operator testing b.Site protocol re-evaluation 2.Imaging system a.Manufacturer testing and attestation b.User acceptance testing and periodic QA i.Phantom Tests ii.Digital Phantom Based Testing iii.Standard QA Testing iv.Remediation Schemes 8.Profile Evolution •Towards additional applications •Towards higher accuracy and precision Supported in part by NIH contract HHSN268201300071C from NIBIB. Collaboration with GE Global Research, no personal support.; S. Chen, Some technologies described in this presentation have been licensed. Mayo Clinic and Dr. Chen have financial interests these technologies.

A simple approach to constructing quasi-Sudoku-based sliced space-filling designs

Sliced Sudoku-based space-filling designs and, more generally, quasi-sliced orthogonal array-based space-filling designs are useful experimental designs in several contexts, including computer experiments with categorical in addition to quantitative inputs and cross-validation. Here, we provide a straightforward construction of doubly orthogonal quasi-Sudoku Latin squares which can be used to generate quasi-sliced orthogonal arrays and, in turn, sliced space-filling designs which achieve uniformity in one- and two-dimensional projections for the full design and uniformity in two-dimensional projections for each slice. These constructions are very practical to implement and yield a spectrum of design sizes and numbers of factors not currently broadly available.

The Effect of Microstructural Variation on the Hydrogen Environment-Assisted Cracking of Monel K-500

The influence of microstructural variation on hydrogen environment-assisted cracking (HEAC) of Monel K-500 was evaluated using five nominally peak-aged lots of material tested under slow-rising stress intensity loading while immersed in NaCl solution under cathodic polarizations. Minimal variation in HEAC resistance among material lots was observed for an applied potential of −950 mVSCE (E app, vs saturated calomel), whereas lot-to-lot variability in the fracture morphology demonstrates a significant difference in the HEAC resistance at the less negative potential of −850 mVSCE, suggesting that relatively severe H environments produce sufficient crack-tip H to minimize the impact of metallurgical differences. Sensitivity analyses accomplished by varying the inputs used in decohesion-based, micromechanical models imply significant variations in HEAC resistance are possible for realistic changes in grain boundary toughness, hydrogen uptake behavior, and yield strength. Grain size, impurity segregation (including the effects of gettering elements), grain boundary character/connectivity, and crack path tortuosity are also considered in the context of HEAC susceptibility. Yield strength, global hydrogen content, as well as impurity segregation to grain boundaries, especially boron and sulfur, are speculatively considered to be the dominant contributions in determining HEAC resistance. Modifications that would incorporate the effects of grain boundary segregation are proposed for the K TH model; detailed validation of such changes require high-fidelity and quantitative inputs for the degree of grain boundary segregation. Regardless, fracture mechanics-based HEAC results, detailed microstructural characterization, and micromechanical modeling were successfully coupled to gain insights into the influences governing the microstructure-dependent HEAC susceptibility of Monel K-500.

Initial Validation of the Sleep Disturbances in Pediatric Cancer Model.

OBJECTIVE : The current study evaluates content validity of the Sleep Disturbance in Pediatric Cancer (SDPC) model using qualitative and quantitative stakeholder input. METHODS : Parents of children (aged: 3-12 years) with acute lymphoblastic leukemia (n = 20) and medical providers (n = 6) participated in semi-structured interviews about child sleep during cancer treatment. They also rated SDPC model component importance on a 0-4 scale and selected the most relevant sleep-related intervention targets. RESULTS : Qualitatively, parents and providers endorsed that changes in the child's psychosocial, environmental, and biological processes affect sleep. Stakeholders rated most model components (parent: 32 of 40; provider: 39 of 41) as important (>2) to child sleep. Parents were most interested in interventions targeting difficulty falling asleep and providers selected irregular sleep habits/scheduling, though groups did not differ significantly. CONCLUSIONS : Stakeholders supported SDPC content validity. The model will inform subsequent measure and intervention development focusing on biological and behavioral factors most salient to sleep disturbances in pediatric cancer.

Scattering strength of the scatterer inducing variability in graphene on silicon oxide

Large variability of carrier mobility of graphene-based field effect transistors hampers graphene science and technology. We show that the number of the scatterer responsible for the observed variability on graphene devices on silicon oxide can be determined by finding the number of hydrogen that can be chemisorbed on graphene. We use the relationship between the number of the scatterer and the mobility of graphene devices to determine that the variability-inducing scatterer possesses scattering strength 10 times smaller than that of adsorbed potassium atoms and 50 times smaller than that of ion-beam induced vacancies. Our results provide an important, quantitative input towards determining the origin of the variability.

Interfacial Study on Solid Electrolyte Interphase at Li Metal Anode: Implication for Li Dendrite Growth

The Solid electrolyte interphase (SEI), either naturally formed or artificially designed, plays a critical role in the stability and durability of Li-ion batteries (LIBs). It is even more important for high energy density electrodes such as Li metal anodes, which is subjected to large volumetric and interfacial variations due to Li deposition/stripping cycles during operation. Currently, there is a lack of understanding of the role of SEI/Li interfaces and their mechanical and electrochemical properties. In this paper, we present an interfacial study to evaluate the two major SEI components, LiF and Li2CO3, based on density functional theory (DFT) calculations. The calculated interfacial energy results show that the Li2CO3/Li interface has higher interfacial mechanical strength. The density of states (DOS) and electrostatic potential results demonstrate that the LiF/Li interface has higher electron tunneling energy barrier from Li metal to SEI. These results provide quantitative inputs for related meso-scale simulations and valuable insights for advanced electrode protective coating design.

Emerging Technologies for Environmental Remediation: Integrating Data and Judgment.

Emerging technologies present significant challenges to researchers, decision-makers, industry professionals, and other stakeholder groups due to the lack of quantitative risk, benefit, and cost data associated with their use. Multi-criteria decision analysis (MCDA) can support early decisions for emerging technologies when data is too sparse or uncertain for traditional risk assessment. It does this by integrating expert judgment with available quantitative and qualitative inputs across multiple criteria to provide relative technology scores. Here, an MCDA framework provides preliminary insights on the suitability of emerging technologies for environmental remediation by comparing nanotechnology and synthetic biology to conventional remediation methods. Subject matter experts provided judgments regarding the importance of criteria used in the evaluations and scored the technologies with respect to those criteria. The results indicate that synthetic biology may be preferred over nanotechnology and conventional methods for high expected benefits and low deployment costs but that conventional technology may be preferred over emerging technologies for reduced risks and development costs. In the absence of field data regarding the risks, benefits, and costs of emerging technologies, structuring evidence-based expert judgment through a weighted hierarchy of topical questions may be helpful to inform preliminary risk governance and guide emerging technology development and policy.

The scientific and technical bases for inputs and outputs of men's pants production

Abstract The scientific and technical basesfor inputs and outputs of men's pants production The research aims to achieving the optimal use of the basic materials and the non-basic materials by adopting the strategy planning method, in addition to planning of inputs and outputs of production by the way that ensure the benefit of this phenomenon in the exploitation of what is available from the production requirements (inputs) to achieve the targeted output. The sample of research was consisted of 10 factories for men's pants production, and the tool of the study is a questionnaire of the scientific and technical foundations for inputs and outputs of men's pants production, and the questionnaire consisted of four major axes raw materials, manpower, exploitation of energy, obstacles. The study found: 1. There are statistically significant differences between the mean scores in the pre and post application of the quantitative input to planning the inputs and outputs to the axis of the materials in favor of post application. 2. There are statistically significant differences between the mean scores in the pre and post application of the quantitative input to planning the inputs and outputs to the axis of the manpower with its dimensions in favor of post application. 3. There are statistically significant differences between the mean scores in the pre and post application of the quantitative input to planning the inputs and outputs to the axis of the exploitation of energy with its dimensions in favor of post application. 4. There are statistically significant differences between the mean scores in the pre and post application of the quantitative input to planning the inputs and outputs to the axis of obstacles with its dimensions in favor of pre application. The study recommended: 1- The necessity of using the input-output analysis method to achieve the optimal exploitation of the available energy. 2- Contracting with the competent authorities with experiences and competencies from universities to conduct a quantitative analysis of the inputs. 3- The management of the factory can take advantage of the study form and from the results and digital indicators which had been obtained as an assistant factor in the rationalization of decisions, especially those related to the formulation of the production plans. ملخص البحث الأسس العلمیة والفنیة لمدخلات ومخرجات إنتاج البنطلون الرجالی یهدف البحث الی تحقیق الاستخدام الأمثل للمواد الأولیة الأساسیة وغیر الأساسیة من خلال اعتماد أسلوب التخطیط الاستراتیجی ، بالإضافة الی تخطیط مدخلات ومخرجات الإنتاج بالشکل الذی یضمن الاستفادة فی هذه الظاهرة فی استغلال ما هو متوفر من مستلزمات إنتاج (المدخلات) لتحقیق المخرجات المستهدفة . وکانت عینة البحث مکونة من (10) مصانع لإنتاج البنطلون الرجالی ، وکانت أداه الدراسة عبارة عن استبیان للأسس العلمیة والفنیة لمدخلات ومخرجات إنتاج البنطلون الرجالی ، وتکون الاستبیان من أربعة محاور رئیسیة الأولیة ، القوی العاملة ، استغلال الطاقة ، . وتوصلت الدراسة الی : 1- وجود فروق دالة إحصائیا بین متوسطی الدرجات فی التطبیق القبلی والبعدی للمدخل الکمی لتخطیط المدخلات والمخرجات لمحور المواد الأولیة لصالح التطبیق البعدی . 2- وجود فروق دالة إحصائیا بین متوسطی الدرجات فی التطبیق القبلی والبعدی للمدخل الکمی لتخطیط المدخلات والمخرجات لمحور القوی العاملة بأبعاده لصالح التطبیق البعدی . 3- وجود فروق دالة إحصائیا بین متوسطی الدرجات فی التطبیق القبلی والبعدی للمدخل الکمی لتخطیط المدخلات والمخرجات لمحور استغلال الطاقة بأبعاده لصالح التطبیق البعدی . 4- وجود فروق دالة إحصائیا بین متوسطی الدرجات فی التطبیق القبلی والبعدی للمدخل الکمی لتخطیط المدخلات والمخرجات لمحور المعوقات بأبعاده لصالح التطبیق القبلی . وأوصت الدراسة بـــ : 1- ضرورة استخدام أسلوب تحلیل المدخلات والمخرجات لتحقیق الاستغلال الأمثل للطاقة المتاحة . 2- التعاقد مع الجهات المختصة ذات الخبرات والکفاءات من الجامعات لإجراء التحلیل الکمی لمدخلاتها. 3- یمکن لإدارة المصنع أن تستفید من نموذج الدراسة ومن النتائج والمؤشرات الرقمیة التی تم التوصل إلیها کعامل مساعد فی ترشید القرارات الخاصة بوضع وصیاغة خطط الإنتاج .

Combined action of crack closure and residual stress under periodic overloads: A fractographic analysis

The close relationship between sequence-sensitive near-tip residual stress and threshold stress intensity raises questions about load interaction models currently in use to estimate fatigue crack growth under variable amplitude loading. In an attempt to address them, experiments were performed on an Al–Cu alloy under specially designed load sequences with periodic overloads. Fractographic evidence from these tests confirms that fatigue crack closure, together with sequence sensitive variation in threshold stress intensity appear to explain all observed results. The fractographic data provide quantitative inputs for improved modeling of variable-amplitude fatigue, particularly at near-threshold crack growth rates. This study appears to suggest that conventional approaches based on the Wheeler and Willenborg residual stress models can provide reasonable estimates only by coincidence. They model the wrong parameter at lower fatigue crack growth rates and may simply not be valid at other growth rates.

Knowledge co-production and boundary work to promote implementation of conservation plans.

Knowledge co-production and boundary work offer planners a new frame for critically designing a social process that fosters collaborative implementation of resulting plans. Knowledge co-production involves stakeholders from diverse knowledge systems working iteratively toward common vision and action. Boundary work is a means of creating permeable knowledge boundaries that satisfy the needs of multiple social groups while guarding the functional integrity of contributing knowledge systems. Resulting products are boundary objects of mutual interest that maintain coherence across all knowledge boundaries. We examined how knowledge co-production and boundary work can bridge the gap between planning and implementation and promote cross-sectoral cooperation. We applied these concepts to well-established stages in regional conservation planning within a national scale conservation planning project aimed at identifying areas for conserving rivers and wetlands of South Africa and developing an institutional environment for promoting their conservation. Knowledge co-production occurred iteratively over 4 years in interactive stake-holder workshops that included co-development of national freshwater conservation goals and spatial data on freshwater biodiversity and local conservation feasibility; translation of goals into quantitative inputs that were used in Marxan to select draft priority conservation areas; review of draft priority areas; and packaging of resulting map products into an atlas and implementation manual to promote application of the priority area maps in 37 different decision-making contexts. Knowledge co-production stimulated dialogue and negotiation and built capacity for multi-scale implementation beyond the project. The resulting maps and information integrated diverse knowledge types of over 450 stakeholders and represented >1000 years of collective experience. The maps provided a consistent national source of information on priority conservation areas for rivers and wetlands and have been applied in 25 of the 37 use contexts since their launch just over 3 years ago. When framed as a knowledge co-production process supported by boundary work, regional conservation plans can be developed into valuable boundary objects that offer a tangible tool for multi-agency cooperation around conservation. Our work provides practical guidance for promoting uptake of conservation science and contributes to an evidence base on how conservation efforts can be improved.

고출력, 고효율 PA 설계를 위한 로드-풀 측정

GaN 전력증폭소자를 이용한 전력증폭기의 고효율 특성을 구현하기 위하여 <TEX>$50{\Omega}$</TEX>으로 정합된 전력증폭소자는 적용 주파수 대역, 출력전력, 효율 특성 선정의 한계가 있으므로 본 연구에서는 source/load-pull 시험을 통한 측정 데이터를 기반으로 고출력, 고효율 특성의 설계 목적에 맞는 정량적 입력 및 출력 임피던스를 추출하여 고효율 전력증폭기를 구현하였다. 구현된 전력증폭기는 2.7-3.1GHz의 주파수 대역에서 25watt(44dBm), 66-76%의 PAE특성 나타낸다. Power amplification device which is matched to <TEX>$50{\Omega}$</TEX> in order to achieve a high efficiency of a power amplifier using a GaN power amplification device, since there is a limit of application frequency bands, output power, efficiency characteristics selection, in this study based on the measurement data through the source/load-pull test, high output power and to extract quantitative input and output impedance that matches the design objectives of high output power, high efficiency, an implementation of the high efficiency power amplifier. Implemented power amplifier is shows 25watt(44dBm), PAE of 66-76% characteristics in the frequency band of 2.7-3.1 GHz.

Can improved agricultural water use efficiency save India’s groundwater?

Irrigated agriculture is placing increasing pressure on finite freshwater resources, especially in developing countries, where water extraction is often unregulated, un-priced and even subsidized. To shift agriculture to a more sustainable use of water without harming the food security and livelihoods of hundreds of millions of smallholders, substantial improvements of water use efficiency will be required. Here, we use detailed hydroclimatic and agricultural data to estimate the potential for the widespread adoption of efficient irrigation technologies to halt the depletion of India’s groundwater resources. Even though we find substantial technical potential for reversing water table declines, we show that the impacts are highly sensitive to assumptions about farmers’ water use decisions. For example, we find that widespread adoption of proven technologies that include drip and sprinkler irrigation has the potential to reduce the amount of excessive extraction of groundwater by two thirds. However, under more realistic assumptions about farmers’ irrigation choices, half of these reductions are lost due to the expansion of irrigated area. Our results suggest that without the introduction of incentives for conservation, much of the potential impact of technology adoption on aquifers may be lost. The analysis provides quantitative input to the debate of incentive versus technology based water policies.

Abstract SY34-01: Infection causing cancer: An update on the global burden

Abstract SY34-01: Infection causing cancer: An update on the global burden

Three-Phase 3D Reconstruction of Li-Ion Batteries Electrodes Via FIB-SEM Tomography

Three-dimensional (3D) reconstructions of lithium-ion battery electrodes provide quantitative microstructural characteristics and input for 3D computational modeling of electrode lithiation and de-lithiation (1-3). In much of the work reported to date, it was not possible to identify all three electrode phases – oxide particles, carbon, and electrolyte – because there was little or no image contrast between the carbon-based epoxy used to fill the pore regions of the electrode (after electrolyte removal) and the carbon phase (4). Recently, it was shown that filling with a silicone resin allows good electrolyte/carbon contrast, although the high viscosity of the resins may make effective pore filling difficult (5). In this work, three-phase 3D reconstructions of a commercial LiCoO2 cathode and lab-made LiFePO4 cathodes (6) are demonstrated using a low viscosity silicone resin as a filling material. As illustrated in Figure 1, contrast among oxide, carbonaceous materials (conducting carbon and binders, CB) and resin-filled porosity (electrolyte space) is obtained using focused ion beam-scanning electron microscopy tomography. Structural parameters including, phase volume fraction, surface area, particle size distribution, pore connectivity and tortuosity are extracted for electrode microstructure-performance correlation analyses. For the commercial LiCoO2 cathode, the electrolyte tortuosity within the electrode is found to be inhomogeneous. For LiFePO­4 cathodes, the microstructure characteristics are compared with conventional electrodes and those with additional large-scale pores added using a sacrificial templating technique. The improved high rate performance found in the templated LiFePO4 electrode can be explained by 3D microstructural characteristics created by the sacrificial template. The present study demonstrates the importance of obtaining all three phases for accurate analysis of microstructure-performance correlations. 1. Z. Liu, J. Scott Cronin, Y.-c. K. Chen-Wiegart, J. R. Wilson, K. J. Yakal-Kremski, J. Wang, K. T. Faber and S. A. Barnett, Journal of Power Sources, 227, 267 (2013). 2. Andreas H. Wiedemann, Graham M. Goldin, Scott A. Barnett, Huayang Zhu and R. J. Kee, Electrochemica Acta, 88, 580 (2013) 3. T. Hutzenlaub, S. Thiele, N. Paust, R. Spotnitz, R. Zengerle and C. Walchshofer, Electrochimica Acta, 115, 131 (2014). 4. J. R. Wilson, J. S. Cronin, S. A. Barnett and S. J. Harris, Journal of Power Sources, 196, 3443 (2011). 5. M. Ender, J. Joos, T. Carraro and E. Ivers-Tiffee, Journal of the Electrochemical Society, 159, A972 (2012). 6. D. P. Singh, F. M. Mulder, A. M. Abdelkader and M. Wagemaker, Advanced Energy Materials, 3, 572 (2013). Figure 1

A revista Perspectivas em Gestão &amp; Conhecimento (PG&amp;C): Criação, gestão editorial e espectro de temas publicados

Objetivo. Apresenta o espectro de temas publicados na revista Perspectivas em Gestão &amp; Conhecimento (PG&amp;C) identificados por meio da frequência de ocorrência das palavras-chave dos artigos. Método. Utiliza análise categorial temática. Assim, foram determinadas como categorias de trabalho os itens de caracterização da revista quanto aos seus dados gerais, processo de gestão editorial e os principais assuntos dos artigos publicados extraídos das palavras-chave, numa abordagem qualitativa-narrativa com aporte de dados quantitativos. Resultados. Evidencia os assuntos com maior índice de freqüência: Gestão do conhecimento, Gestão da informação, Ciência da Informação, Aprendizagem, Sistemas de informação e Tecnologias de informação. Este resultado expressa a tendência dos estudos convergentes entre a Administração e a Ciência da Informação. Conclusões. Conclui que o periódico PG&amp;C já se firmou como veículo de referência nacional para diversas áreas que tratam da Gestão e do Conhecimento como objeto inter-relacional de estudo, não deixando de reconhecer aí a visibilidade e interesse internacional.

A Quantitative and Dynamic Model of the Arabidopsis Flowering Time Gene Regulatory Network

Various environmental signals integrate into a network of floral regulatory genes leading to the final decision on when to flower. Although a wealth of qualitative knowledge is available on how flowering time genes regulate each other, only a few studies incorporated this knowledge into predictive models. Such models are invaluable as they enable to investigate how various types of inputs are combined to give a quantitative readout. To investigate the effect of gene expression disturbances on flowering time, we developed a dynamic model for the regulation of flowering time in Arabidopsis thaliana. Model parameters were estimated based on expression time-courses for relevant genes, and a consistent set of flowering times for plants of various genetic backgrounds. Validation was performed by predicting changes in expression level in mutant backgrounds and comparing these predictions with independent expression data, and by comparison of predicted and experimental flowering times for several double mutants. Remarkably, the model predicts that a disturbance in a particular gene has not necessarily the largest impact on directly connected genes. For example, the model predicts that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS (SOC1) mutation has a larger impact on APETALA1 (AP1), which is not directly regulated by SOC1, compared to its effect on LEAFY (LFY) which is under direct control of SOC1. This was confirmed by expression data. Another model prediction involves the importance of cooperativity in the regulation of APETALA1 (AP1) by LFY, a prediction supported by experimental evidence. Concluding, our model for flowering time gene regulation enables to address how different quantitative inputs are combined into one quantitative output, flowering time.

Characterizing the concentration of Cryptosporidium in Australian surface waters for setting health-based targets for drinking water treatment.

It is proposed that the next revision of the Australian Drinking Water Guidelines will include 'health-based targets', where the required level of potable water treatment quantitatively relates to the magnitude of source water pathogen concentrations. To quantify likely Cryptosporidium concentrations in southern Australian surface source waters, the databases for 25 metropolitan water supplies with good historical records, representing a range of catchment sizes, land use and climatic regions were mined. The distributions and uncertainty intervals for Cryptosporidium concentrations were characterized for each site. Then, treatment targets were quantified applying the framework recommended in the World Health Organization Guidelines for Drinking-Water Quality 2011. Based on total oocyst concentrations, and not factoring in genotype or physiological state information as it relates to infectivity for humans, the best estimates of the required level of treatment, expressed as log10 reduction values, ranged among the study sites from 1.4 to 6.1 log10. Challenges associated with relying on historical monitoring data for defining drinking water treatment requirements were identified. In addition, the importance of quantitative microbial risk assessment input assumptions on the quantified treatment targets was investigated, highlighting the need for selection of locally appropriate values.

A logistics sector’s perspective of factors and risks within the business environment that influence supply chains’ effectiveness: An explorative mixed method study

Background: Supply chains in South Africa operate in a challenging business environment. This environment influences the efficiency and effectiveness of South African businesses and supply chains. These factors further influence the competitiveness of products produced in the country, the economic growth and development of South Africa.Objectives: The purpose of this study was two-fold: Firstly, to obtain insight into the main business environment risks and other factors, from a logistics perspective; and secondly, to demonstrate the use of methodology not often used in logistics research − the sequential mixed method.Method: The explorative study was conducted amongst logistics service providers and cargo owners in 2013 by means of a sequential mixed method study, consisting of a survey to determine the importance of risk factors in the business environment, followed by a qualitative study in the form of a focus group discussion to obtain richer data and insight into these risks and factors. The results of these two methods were integrated with industry literature.Results: It was found that increasing transportation costs, operational management of infrastructure and human resources-related problems pose the biggest challenges in the logistics industry. In addition, it was found that the mixed method research study has application possibilities in logistics research.Conclusion: The factors identified as particularly problematic for the logistics industry, namely ineffective operational management of infrastructure, the general conditions in the labour market and increasing costs (to some extent) are outside the control of individual organisations. However, organisations can control how they react and mitigate these risk factors. It is shown that these factors and risks can change overnight. The use of the explorative mixed method in obtaining qualitative and quantitative inputs and integrating it with existing literature proved to be a workable and usable methodology.

Comparing the sustainability of U.S. electricity options through multi-criteria decision analysis

Sustainable energy decision-making requires comparing energy options across a wide range of economic, environmental, social and technical implications. However, such comparisons based on quantitative data are currently limited at the national level. This is the first comparison of 13 currently operational renewable and non-renewable options for new US electricity generation using multi-criteria decision analysis with quantitative input values (minimum, nominal, and maximum) for 8 sustainability criteria (levelized cost of energy, life cycle greenhouse gas and criteria air pollutant emissions, land and water use, accident-related fatalities, jobs, and annual capacity factor) and 10 representative decision-maker preference scenarios. Results across several preference scenarios indicate that biopower and geothermal (flash and binary) currently score highest in sustainability for the US. Other renewable energy technologies generally offer substantial sustainability improvements over fossil fuel or nuclear technologies, and nuclear is preferable to fossil fuels in most scenarios. The relatively low ranking of natural gas combined cycle in most preference scenarios should encourage caution in adopting NGCC as a “bridge” to renewables. Although NGCC ranks high under economic and technical preference scenarios, renewables actually rank higher in both scenarios (hydro – economic; geothermal and biopower – technical).