Showing papers by "University of Delaware published in 2013"
Alternatives1, John Innes Centre2, University of Bonn3, University of North Carolina at Chapel Hill4, University of Wisconsin-Madison5, University of Utah6, University of Southern California7, University of Edinburgh8, University of Warwick9, Harvard University10, University College Cork11, University of Queensland12, University of Hertfordshire13, University of Potsdam14, University of California, San Diego15, Goethe University Frankfurt16, University of California, San Francisco17, University of Delaware18, Uppsala University19, Medical University of Vienna20, J. Craig Venter Institute21, University of Hawaii at Manoa22, Leibniz Association23, University of Iowa24, University of Aberdeen25, Georgia Institute of Technology26, University of California, Berkeley27, University of Groningen28, Princeton University29, University of Marburg30, University of Illinois at Urbana–Champaign31, Saarland University32, Norwegian University of Life Sciences33, Massey University34, Toyama Prefectural University35, ETH Zurich36, University of Saskatchewan37, Rutgers University38, Scripps Research Institute39, University of Helsinki40, Texas A&M University41, National Institutes of Health42, Technical University of Berlin43, University of Otago44, University of Cambridge45, University of Alberta46, Michigan State University47, Hofstra University48
TL;DR: This review presents recommended nomenclature for the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), a rapidly growing class of natural products.
1,560 citations
Book•
22 Jan 2013TL;DR: In this paper, the authors present an overview of the use of Intensive Longitudinal Methods (ILM) and their application in the analysis of daily conflict and intra-relationship data.
Abstract: 1. Introduction to Intensive Longitudinal Methods 1.1 What Are Intensive Longitudinal Methods? 1.2 Applications of Intensive Longitudinal Methods 1.3 Why Use Intensive Longitudinal Methods? 1.4 Goals for This Book and Intended Audience 1.5 Organization of This Book 1.6 Recommended Readings 2. Types of Intensive Longitudinal Designs 2.1 Chapter Overview 2.2 Strengths of Intensive Longitudinal Designs 2.3 Types of Research Questions 2.4 Types of Designs and Prototypical Examples 2.5 Limitations of Intensive Longitudinal Designs 2.6 Which Intensive Longitudinal Design Is Best for You? 2.7 Chapter Summary 2.8 Recommended Readings 3. Fundamentals of Intensive Longitudinal Data 3.1 Chapter Overview 3.2 An Example Dataset 3.3 Between-Subjects and Within-Subjects Levels of Analysis 3.4 Allowing for Between-Subjects Heterogeneity: Random Effects 3.5 Taking Account of Time 3.6 How Many Independent Units Are There in Intensive Longitudinal Datasets? 3.7 Choosing an Appropriate Zero Point For X 3.8 Chapter Summary 3.9 Recommended Readings 4. Modeling the Time Course of Continuous Outcomes 4.1 Chapter Overview 4.2 The Example Intervention Dataset 4.3 An Application of Linear Growth Curve Analysis 4.4 Example Write-Up of Intervention Study Data 4.5 Chapter Summary 4.6 Recommended Readings 5. Modeling the Within-Subject Causal Process 5.1 Chapter Overview 5.2 Conceptualizing a Within-Subject Causal Process 5.3 Example Daily Conflict and Intimacy Dataset 5.4 Multilevel Causal Model Linking Daily Conflict and Intimacy 5.5 Modeling a Process with Missing Repeated Measures Data 5.6 When the Intervals between Measurements Are Unequal 5.7 Example Write-Up of Daily Conflict Study Data 5.8 Chapter Summary 5.9 Recommended Readings 6. Modeling Categorical Outcomes 6.1 Chapter Overview 6.2 Exploring the Example Dataset 6.3 A Longitudinal Multilevel Model Linking Morning Anger to the Incidence of Daily Conflict in Couples 6.4 Implementation in SAS PROC GLIMMIX 6.5 Implementation in IBM SPSS GENLINMIXED 6.6 Implementation in Mplus 6.7 Chapter Summary 6.8 Recommended Readings 7. Psychometrics of Intensive Longitudinal Measures of Emotional States 7.1 Chapter Overview 7.2 Basic Ideas about Random Measurement Error 7.3 Making Use of Generalizability Theory 7.4 Making Use of Multilevel Confirmatory Factor Analysis 7.5 Chapter Summary 7.6 Recommended Readings 8. Design and Analysis of Intensive Longitudinal Studies of Distinguishable Dyads 8.1 Chapter Overview 8.2 Motivation for Studying the Everyday Lives of Dyads 8.3 Methodological and Design Issues in Intensive Longitudinal Studies of Distinguishable Dyads 8.4 The Multilevel Model for Intensive Longitudinal Data from Distinguishable Dyads 8.5 Example Write-Up of Dyadic Study Data 8.6 Chapter Summary 8.7 Recommended Readings 9. Within-Subject Mediation Analysis 9.1 Chapter Overview 9.2 Single-Level Mediation to Multilevel Mediation 9.3 Empirical Example 9.4 Implementing Within-Subject Mediation in Statistical Software 9.5 Interpretation of Results 9.6 Chapter Summary 9.7 Recommended Readings 10. Statistical Power for Intensive Longitudinal Designs 10.1 Chapter Overview 10.2 Approaches to Power 10.3 Power in Multilevel Models 10.4 Power for the Marital Therapy and Intimacy Example 10.5 Power for the Daily Conflicts and Intimacy Example 10.6 Power Analysis for the Daily Conflict Categorical Outcomes Example 10.7 Power for the Dyadic Process Example 10.8 Power for the Within-Subject Multilevel Mediation Example 10.9 Chapter Summary 10.10 Recommended Readings
1,210 citations
TL;DR: The sources, exchanges and fates of carbon in the coastal ocean and how anthropogenic activities have altered the carbon cycle are discussed.
Abstract: The carbon cycle of the coastal ocean is a dynamic component of the global carbon budget. But the diverse sources and sinks of carbon and their complex interactions in these waters remain poorly understood. Here we discuss the sources, exchanges and fates of carbon in the coastal ocean and how anthropogenic activities have altered the carbon cycle. Recent evidence suggests that the coastal ocean may have become a net sink for atmospheric carbon dioxide during post-industrial times. Continued human pressures in coastal zones will probably have an important impact on the future evolution of the coastal ocean's carbon budget.
1,091 citations
TL;DR: These technologies such as multiple-input multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM), cognitive radio, network coding, cooperative communication, etc.
Abstract: Reducing energy consumption in wireless communications has attracted increasing attention recently. Advanced physical layer techniques such as multiple-input multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM), cognitive radio, network coding, cooperative communication, etc.; new network architectures such as heterogeneous networks, distributed antennas, multi-hop cellulars, etc.; as well as radio and network resource management schemes such as various cross-layer optimization algorithms, dynamic power saving, multiple radio access technologies coordination, etc. have been proposed to address this issue. In this article, we overview these technologies and present the state-of-the-art on each aspect. Some challenges that need to be solved in the area are also described.
954 citations
TL;DR: A facile method to prepare chemically stable and processable polymeric materials through the direct copolymerization of elemental sulfur with vinylic monomers is reported, which leads to well-defined sulfur-rich micropatterned films created by imprint lithography.
Abstract: An excess of elemental sulfur is generated annually from hydrodesulfurization in petroleum refining processes; however, it has a limited number of uses, of which one example is the production of sulfuric acid. Despite this excess, the development of synthetic and processing methods to convert elemental sulfur into useful chemical substances has not been investigated widely. Here we report a facile method (termed ‘inverse vulcanization’) to prepare chemically stable and processable polymeric materials through the direct copolymerization of elemental sulfur with vinylic monomers. This methodology enabled the modification of sulfur into processable copolymer forms with tunable thermomechanical properties, which leads to well-defined sulfur-rich micropatterned films created by imprint lithography. We also demonstrate that these copolymers exhibit comparable electrochemical properties to elemental sulfur and could serve as the active material in Li–S batteries, exhibiting high specific capacity (823 mA h g−1 at 100 cycles) and enhanced capacity retention. A polymerization method for converting elemental sulfur into a chemically stable, processable and electrochemically active copolymer has been described. This methodology — termed inverse vulcanization — is conducted by a one-step process using liquid sulfur, as both reaction medium and reactant, and vinylic comonomers to form polymeric materials with a high content of sulfur (50–90 wt%).
938 citations
TL;DR: Three separate size regimes below 2-nm diameter are identified that build up a physically, chemically, and dynamically consistent framework on atmospheric nucleation—more specifically, aerosol formation via neutral pathways.
Abstract: Atmospheric nucleation is the dominant source of aerosol particles in the global atmosphere and an important player in aerosol climatic effects. The key steps of this process occur in the sub–2-nanometer (nm) size range, in which direct size-segregated observations have not been possible until very recently. Here, we present detailed observations of atmospheric nanoparticles and clusters down to 1-nm mobility diameter. We identified three separate size regimes below 2-nm diameter that build up a physically, chemically, and dynamically consistent framework on atmospheric nucleation—more specifically, aerosol formation via neutral pathways. Our findings emphasize the important role of organic compounds in atmospheric aerosol formation, subsequent aerosol growth, radiative forcing and associated feedbacks between biogenic emissions, clouds, and climate.
890 citations
TL;DR: In this article, molybdenum carbide (β-Mo2C) nanoparticles are prepared by in situ carburization of ammonium molydate on carbon nanotubes and XC-72R carbon black without using any gaseous carbon source.
Abstract: In an attempt to tailor low-cost, precious-metal-free electrocatalysts for water electrolysis in acid, molybdenum carbide (β-Mo2C) nanoparticles are prepared by in situ carburization of ammonium molybdate on carbon nanotubes and XC-72R carbon black without using any gaseous carbon source. The formation of Mo2C is investigated by thermogravimetry and in situ X-ray diffraction. X-ray absorption analysis reveals that Mo2C nanoparticles are inlaid or anchored into the carbon supports, and the electronic modification makes the surface exhibit a relatively moderate Mo–H bond strength. It is found that carbon nanotube-supported Mo2C showed superior electrocatalytic activity and stability in the hydrogen evolution reaction (HER) compared to the bulk Mo2C. An overpotential of 63 mV for driving 1 mA cm−2 of current density was measured for the nanotube-supported Mo2C catalysts; this exceeds the activity of analogous Mo2C catalysts. The enhanced electrochemical activity is facilitated by unique effects of the anchored structure coupled with the electronic modification.
834 citations
TL;DR: These two neutrino-induced events could be a first indication of an astrophysical neutrinos flux; the moderate significance, however, does not permit a definitive conclusion at this time.
Abstract: We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04 +/- 0.16 and 1.14 +/- 0.17 PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current nu(e,mu,tau) ((nu) over bar (e,mu,tau)) or charged-current nu(e) ((nu) over bar (e)) interactions within the IceCube detector. The events were discovered in a search for ultrahigh energy neutrinos using data corresponding to 615.9 days effective live time. The expected number of atmospheric background is 0.082 +/- 0.004(stat)(-0.057)(+0.041)(syst). The probability of observing two or more candidate events under the atmospheric background-only hypothesis is 2.9 x 10(-3) (2.8 sigma) taking into account the uncertainty on the expected number of background events. These two events could be a first indication of an astrophysical neutrino flux; the moderate significance, however, does not permit a definitive conclusion at this time.
786 citations
TL;DR: In this paper, the authors demonstrate that the HER exchange current density in alkaline solutions can be correlated with calculated hydrogen binding energy (HBE) on the metal surfaces via a volcano type of relationship.
Abstract: The slow reaction kinetics of the hydrogen evolution and oxidation reactions (HER/HOR) on platinum in alkaline electrolytes hinders the development of alkaline electrolysers, solar hydrogen cells and alkaline fuel cells. A fundamental understanding of the exchange current density of the HER/HOR in alkaline media is critical for the search and design of highly active electrocatalysts. By studying the HER on a series of monometallic surfaces, we demonstrate that the HER exchange current density in alkaline solutions can be correlated with the calculated hydrogen binding energy (HBE) on the metal surfaces via a volcano type of relationship. The HER activity varies by several orders of magnitude from Pt at the peak of the plot to W and Au located on the bottom of each side of the plot, similar to the observation in acids. Such a correlation suggests that the HBE can be used as a descriptor for identifying electrocatalysts for HER/HOR in alkaline media, and that the HER exchange current density can be tuned by modifying the surface chemical properties.
769 citations
TL;DR: A tutorial review on covalent adaptable networks (CANs), in which covalently crosslinked networks are formed such that triggerable, reversible chemical structures persist throughout the network, and how the application of a stimulus causes these materials to alter their shape, topography, and properties is provided.
Abstract: Covalently crosslinked materials, classically referred to as thermosets, represent a broad class of elastic materials that readily retain their shape and molecular architecture through covalent bonds that are ubiquitous throughout the network structure. These materials, in particular in their swollen gel state, have been widely used as stimuli responsive materials with their ability to change volume in response to changes in temperature, pH, or other solvent conditions and have also been used in shape memory applications. However, the existence of a permanent, unalterable shape and structure dictated by the covalently crosslinked structure has dramatically limited their abilities in this and many other areas. These materials are not generally reconfigurable, recyclable, reprocessable, and have limited ability to alter permanently their stress state, topography, topology, or structure. Recently, a new paradigm has been explored in crosslinked polymers – that of covalent adaptable networks (CANs) in which covalently crosslinked networks are formed such that triggerable, reversible chemical structures persist throughout the network. These reversible covalent bonds can be triggered through molecular triggers, light or other incident radiation, or temperature changes. Upon application of this stimulus, rather than causing a temporary shape change, the CAN structure responds by permanently adjusting its structure through either reversible addition/condensation or through reversible bond exchange mechanisms, either of which allow the material to essentially reequilibrate to its new state and condition. Here, we provide a tutorial review on these materials and their responsiveness to applied stimuli. In particular, we review the broad classification of these materials, the nature of the chemical bonds that enable the adaptable structure, how the properties of these materials depend on the reversible structure, and how the application of a stimulus causes these materials to alter their shape, topography, and properties.
748 citations
TL;DR: The Cherenkov Telescope Array (CTA) as discussed by the authors is a very high-energy (VHE) gamma ray observatory with an international collaboration with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America.
TL;DR: In this paper, the authors categorize the types of tensions that arise between social missions and business ventures, emphasizing their prevalence and variety, and explore how four different organizational theories offer insight into these tensions.
Abstract: In a world filled with poverty, environmental degradation, and moral injustice, social enterprises offer a ray of hope. These organizations seek to achieve social missions through business ventures. Yet social missions and business ventures are associated with divergent goals, values, norms, and identities. Attending to them simultaneously creates tensions, competing demands, and ethical dilemmas. Effectively understanding social enterprises therefore depends on insight into the nature and management of these tensions. While existing research recognizes tensions between social missions and business ventures, we lack any systematic analysis. Our paper addresses this issue. We first categorize the types of tensions that arise between social missions and business ventures, emphasizing their prevalence and variety. We then explore how four different organizational theories offer insight into these tensions, and we develop an agenda for future research. We end by arguing that a focus on social-business tensions not only expands insight into social enterprises, but also provides an opportunity for research on social enterprises to inform traditional organizational theories. Taken together, our analysis of tensions in social enterprises integrates and seeks to energize research on this expanding phenomenon.
Book•
22 Oct 2013TL;DR: The application of chemical kinetics to soil systems is discussed in this paper, where the authors present a model of Inorganic and Organic Reactions in Soils, as well as the mechanisms of Rapid Reactions on Soil Constituents using Relaxation Methods.
Abstract: Introduction. Application of Chemical Kinetics to Soil Systems. Kinetic Methodologies and Data Interpretation for Diffusion-Controlled Reactions. Kinetics and Mechanisms of Rapid Reactions on Soil Constituents Using Relaxation Methods. Ion Exchange Kinetics on Soils and Soil Constituents. Kinetics of Pesticide and Organic Pollutant Reactions. Rates of Chemical Weathering. Redox Kinetics. Kinetic Modeling of Inorganic and Organic Reactions in Soils. Bibliography. Index.
University of Toledo1, University College Dublin2, Indiana University3, Qatar Airways4, The Chinese University of Hong Kong5, University of Virginia6, University of Sydney7, University of Delaware8, University of Kentucky9, Radboud University Nijmegen Medical Centre10, University of Queensland11, University of North Carolina at Chapel Hill12
TL;DR: There is a need to provide standards for patient/participant selection criteria in research focused on CAI, with justifications using the best available evidence.
Abstract: While research on chronic ankle instability (CAI) and awareness of its impact on society and health care systems has grown substantially in the last 2 decades, the inconsistency in participant/patient selection criteria across studies presents a potential obstacle to addressing the problem properly. This major gap within the literature limits the ability to generalise this evidence to the target patient population. Therefore, there is a need to provide standards for patient/participant selection criteria in research focused on CAI with justifications using the best available evidence. The International Ankle Consortium provides this position paper to present and discuss an endorsed set of selection criteria for patients with CAI based on the best available evidence to be used in future research and study designs. These recommendations will enhance the validity of research conducted in this clinical population with the end goal of bringing the research evidence to the clinician and patient.
TL;DR: Extended X-ray absorption fine structure spectroscopy and Car-Parrinello molecular dynamics simulations indicate a strong interaction between the Cr cation and the glucose molecule whereby some water molecules are displaced from the first coordination sphere of Cr by the glucose to enable ring-opening and isomerization of glucose
Abstract: 5-(Hydroxymethyl)furfural (HMF) and levulinic acid production from glucose in a cascade of reactions using a Lewis acid (CrCl3) catalyst together with a Bronsted acid (HCl) catalyst in aqueous media is investigated. It is shown that CrCl3 is an active Lewis acid catalyst in glucose isomerization to fructose, and the combined Lewis and Bronsted acid catalysts perform the isomerization and dehydration/rehydration reactions. A CrCl3 speciation model in conjunction with kinetics results indicates that the hydrolyzed Cr(III) complex [Cr(H2O)5OH](2+) is the most active Cr species in glucose isomerization and probably acts as a Lewis acid-Bronsted base bifunctional site. Extended X-ray absorption fine structure spectroscopy and Car-Parrinello molecular dynamics simulations indicate a strong interaction between the Cr cation and the glucose molecule whereby some water molecules are displaced from the first coordination sphere of Cr by the glucose to enable ring-opening and isomerization of glucose. Additionally, complex interactions between the two catalysts are revealed: Bronsted acidity retards aldose-to-ketose isomerization by decreasing the equilibrium concentration of [Cr(H2O)5OH](2+). In contrast, Lewis acidity increases the overall rate of consumption of fructose and HMF compared to Bronsted acid catalysis by promoting side reactions. Even in the absence of HCl, hydrolysis of Cr(III) decreases the solution pH, and this intrinsic Bronsted acidity drives the dehydration and rehydration reactions. Yields of 46% levulinic acid in a single phase and 59% HMF in a biphasic system have been achieved at moderate temperatures by combining CrCl3 and HCl.
TL;DR: Fe2(BDP)3 (BDP2– = 1,4-benzenedipyrazolate), a highly stable framework with triangular channels that effect the separation of hexane isomers according to the degree of branching is reported, showing preliminary promise for enhancing a separations process central to gasoline production.
Abstract: Metal-organic frameworks can offer pore geometries that are not available in zeolites or other porous media, facilitating distinct types of shape-based molecular separations. Here, we report Fe2(BDP)3 (BDP(2-) = 1,4-benzenedipyrazolate), a highly stable framework with triangular channels that effect the separation of hexane isomers according to the degree of branching. Consistent with the varying abilities of the isomers to wedge along the triangular corners of the structure, adsorption isotherms and calculated isosteric heats indicate an adsorption selectivity order of n-hexane > 2-methylpentane > 3-methylpentane > 2,3-dimethylbutane ≈ 2,2-dimethylbutane. A breakthrough experiment performed at 160°C with an equimolar mixture of all five molecules confirms that the dibranched isomers elute first from a bed packed with Fe2(BDP)3, followed by the monobranched isomers and finally linear n-hexane. Configurational-bias Monte Carlo simulations confirm the origins of the molecular separation.
TL;DR: This review provides insight into emerging degradable and cell-compatible hydrogels for understanding and modulating cell behavior for various bioengineering applications.
Abstract: Degradable and cell-compatible hydrogels can be designed to mimic the physical and biochemical characteristics of native extracellular matrices and provide tunability of degradation rates and related properties under physiological conditions. Hence, such hydrogels are finding widespread application in many bioengineering fields, including controlled bioactive molecule delivery, cell encapsulation for controlled three-dimensional culture, and tissue engineering. Cellular processes, such as adhesion, proliferation, spreading, migration, and differentiation, can be controlled within degradable, cell-compatible hydrogels with temporal tuning of biochemical or biophysical cues, such as growth factor presentation or hydrogel stiffness. However, thoughtful selection of hydrogel base materials, formation chemistries, and degradable moieties is necessary to achieve the appropriate level of property control and desired cellular response. In this review, hydrogel design considerations and materials for hydrogel preparation, ranging from natural polymers to synthetic polymers, are overviewed. Recent advances in chemical and physical methods to crosslink hydrogels are highlighted, as well as recent developments in controlling hydrogel degradation rates and modes of degradation. Special attention is given to spatial or temporal presentation of various biochemical and biophysical cues to modulate cell response in static (i.e., non-degradable) or dynamic (i.e., degradable) microenvironments. This review provides insight into the design of new cell-compatible, degradable hydrogels to understand and modulate cellular processes for various biomedical applications.
TL;DR: The OARSI recommended set of performance-based tests of physical function represents the tests of typical activities relevant to individuals diagnosed with hip or knee OA and following joint replacements and are complementary to patient-reported measures.
Stig E. Bojesen1, Stig E. Bojesen2, Karen A. Pooley3, Sharon E. Johnatty4 +452 more•Institutions (129)
TL;DR: Using the Illumina custom genotyping array iCOGs, SNPs at the TERT locus in breast, ovarian and BRCA1 mutation carrier cancer cases and controls and leukocyte telomere measurements are analyzed to find associations cluster into three independent peaks.
Abstract: TERT-locus SNPs and leukocyte telomere measures are reportedly associated with risks of multiple cancers. Using the Illumina custom genotyping array iCOG, we analyzed similar to 480 SNPs at the TERT locus in breast (n = 103,991), ovarian (n = 39,774) and BRCA1 mutation carrier (n = 11,705) cancer cases and controls. Leukocyte telomere measurements were also available for 53,724 participants. Most associations cluster into three independent peaks. The minor allele at the peak 1 SNP rs2736108 associates with longer telomeres (P = 5.8 x 10(-7)), lower risks for estrogen receptor (ER)-negative (P = 1.0 x 10(-8)) and BRCA1 mutation carrier (P = 1.1 x 10(-5)) breast cancers and altered promoter assay signal. The minor allele at the peak 2 SNP rs7705526 associates with longer telomeres (P = 2.3 x 10(-14)), higher risk of low-malignant-potential ovarian cancer (P = 1.3 x 10(-15)) and greater promoter activity. The minor alleles at the peak 3 SNPs rs10069690 and rs2242652 increase ER-negative (P = 1.2 x 10(-12)) and BRCA1 mutation carrier (P = 1.6 x 10-14) breast and invasive ovarian (P = 1.3 x 10(-11)) cancer risks but not via altered telomere length. The cancer risk alleles of rs2242652 and rs10069690, respectively, increase silencing and generate a truncated TERT splice variant.
TL;DR: In this paper, the authors model many combinations of renewable electricity sources (inland wind, offshore wind, and photovoltaics) with electrochemical storage (batteries and fuel cells), incorporated into a large grid system (72 GW).
TL;DR: This Minireview discusses several important recent studies in developing nanostructured pseudocapacitor electrodes, and summarizes three major parameters that are the most important in determining the performance of electrode materials.
Abstract: The depletion of traditional energy resources as well as the desire to reduce high CO(2) emissions associated with energy production means that energy storage is now becoming more important than ever. New functional electrode materials are urgently needed for next-generation energy storage systems, such as supercapacitors or batteries, to meet the ever increasing demand for higher energy and power densities. Advances in nanotechnology are essential to meet those future challenges. It is critical to develop ways of synthesizing new nanomaterials with enhanced properties or combinations of properties to meet future challenges. In this Minireview we discuss several important recent studies in developing nanostructured pseudocapacitor electrodes, and summarize three major parameters that are the most important in determining the performance of electrode materials. A technique to optimize these parameters simultaneously and to achieve both high energy and power densities is also introduced.
TL;DR: In this article, a review of carbon-based nanostructured materials as electrodes in electrochemical capacitors and their primary applications is presented. And the future trend of electrochemical supercapacitors is discussed.
TL;DR: A review of academic research on audit quality can be found in this paper, where the authors present a review of existing definitions of audit quality and describe general frameworks for establishing audit quality.
Abstract: This study presents a review of academic research on audit quality. We begin with a review of existing definitions of audit quality and describe general frameworks for establishing audit quality. Next, we summarize research on indicators of audit quality, such as inputs, process, and outcomes. Finally, we offer some suggestions for future research. The study should be useful to academics interested in audit quality as well as to the Public Company Accounting Oversight Board (PCAOB) and other regulators.
TL;DR: In this paper, the authors extended Mehrabian and Russell's Stimulus-Organism-Response model to include both external (i.e. reputation) and internal source of information (e.g., website quality) as stimuli which affect consumers' response systems.
Abstract: Purpose – This research extends Mehrabian and Russell's Stimulus‐Organism‐Response model to include both external (i.e. reputation) and internal source of information (i.e. website quality) as stimuli which affect consumers' response systems. The purpose of this paper is to test a more comprehensive model consisting of reputation and website quality (stimuli), cognition and emotion (organism) and purchase intention (response).Design/methodology/approach – In total, 219 usable questionnaires were obtained at a large Midwestern university through online survey. Structural equation modeling (SEM) was employed for data analyses.Findings – Reputation had a significant positive effect on consumers' emotion and significant negative effect on perceived risk. All four website quality dimensions had significant negative effects on perceived risk and significant positive effects on emotion, except for customer service. Perceived risk had a significant negative effect on consumers' emotion, and both perceived risk an...
TL;DR: It is estimated that the breast cancer lifetime risks for the5% of BRCA1 carriers at lowest risk are 28%–50% compared to 81%–100% for the 5% at highest risk, and the ovarian cancer lifetime risk is 63% or higher, based on the known cancer risk-modifying loci.
Abstract: BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7 x 10(-8), HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4 x 10(-8), HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4 x 10(-8), HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific association. The 17q21.31 locus was also associated with ovarian cancer risk in 8,211 BRCA2 carriers (P = 2 x 10(-4)). These loci may lead to an improved understanding of the etiology of breast and ovarian tumors in BRCA1 carriers. Based on the joint distribution of the known BRCA1 breast cancer risk-modifying loci, we estimated that the breast cancer lifetime risks for the 5% of BRCA1 carriers at lowest risk are 28%-50% compared to 81%-100% for the 5% at highest risk. Similarly, based on the known ovarian cancer risk-modifying loci, the 5% of BRCA1 carriers at lowest risk have an estimated lifetime risk of developing ovarian cancer of 28% or lower, whereas the 5% at highest risk will have a risk of 63% or higher. Such differences in risk may have important implications for risk prediction and clinical management for BRCA1 carriers.
TL;DR: This study uses molecular dynamics simulations to probe the structure, dynamics, and energetics of hydrated CaCO3 clusters and lattice gas simulations to explore the behavior of cluster populations before nucleation and predicts formation of a dense liquid phase through liquid-liquid separation within the concentration range in which clusters are observed.
Abstract: Recent experimental observations of the onset of calcium carbonate (CaCO3) mineralization suggest the emergence of a population of clusters that are stable rather than unstable as predicted by classical nucleation theory. This study uses molecular dynamics simulations to probe the structure, dynamics, and energetics of hydrated CaCO3 clusters and lattice gas simulations to explore the behavior of cluster populations before nucleation. Our results predict formation of a dense liquid phase through liquid-liquid separation within the concentration range in which clusters are observed. Coalescence and solidification of nanoscale droplets results in formation of a solid phase, the structure of which is consistent with amorphous CaCO3. The presence of a liquid-liquid binodal enables a diverse set of experimental observations to be reconciled within the context of established phase-separation mechanisms.
TL;DR: A search for muon neutrinos from dark matter annihilation in the center of the Sun with the 79-string configuration of the IceCube neutrino telescope is performed, lowering the energy threshold and extending the search to the austral summer.
Abstract: We have performed a search for muon neutrinos from dark matter annihilation in the center of the Sun with the 79-string configuration of the IceCube neutrino telescope. For the first time, the DeepCore subarray is included in the analysis, lowering the energy threshold and extending the search to the austral summer. The 317 days of data collected between June 2010 and May 2011 are consistent with the expected background from atmospheric muons and neutrinos. Upper limits are set on the dark matter annihilation rate, with conversions to limits on spin-dependent and spin-independent scattering cross sections of weakly interacting massive particles (WIMPs) on protons, for WIMP masses in the range 20-5000 GeV=c(2). These are the most stringent spin-dependent WIMP-proton cross section limits to date above 35 GeV=c(2) for most WIMP models.
TL;DR: In this paper, gas adsorption data for ethylene, ethane, propylene, and propane at 45, 60, and 80 °C for the entire series was presented.
Abstract: A significant reduction in the energy costs associated with the cryogenic separation of ethylene–ethane and propylene–propane mixtures could potentially be realized through the use of selective solid adsorbents that operate at higher temperatures. The metal–organic frameworks M2(dobdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobdc4− = 2,5-dioxido-1,4-benzenedicarboxylate) are of particular interest for this application, owing to their high density of coordinatively unsaturated M2+ cation sites that can selectively interact with unsaturated hydrocarbons. Here, we present gas adsorption data for ethylene, ethane, propylene, and propane at 45, 60, and 80 °C for the entire series. The means of sample preparation and activation is found to be important for achieving high separation selectivities and capacities. While all of the compounds investigated show good performance characteristics, Fe2(dobdc) and Mn2(dobdc) exhibit the highest selectivities for the separation of ethylene–ethane and propylene–propane mixtures, respectively. Crystal structures determined from neutron powder diffraction data elucidate the binding of ethane, ethylene, and propylene in Mn2(dobdc) and Co2(dobdc).
TL;DR: Under a strong acidic environment, a high turnover frequency (TOF) of ~2.2 × 10(-3) s(-1) per Co atom was achieved, which is more than twice the TOF of traditional hard-templated, mesoporous Co3O4.
Abstract: Oxygen evolution from water by use of earth-abundant element-based catalysts is crucial for mass solar fuel production. In this report, a mesoporous cobalt oxide with an ultrahigh surface area (up to 250 m2·g–1) has been fabricated through Mg substitution in the mesoporous Co3O4 spinel, followed by a Mg-selective leaching process. Approximately a third of Mg cations were removed in the leaching process, resulting in a highly porous cobalt oxide with a significant amount of defects in the spinel structure. The activated mesoporous cobalt oxide exhibited high oxygen evolution activities in both the visible-light-driven [Ru(bpy)3]2+–persulfate system and the Ce4+/Ce3+ chemical water oxidation system. Under a strong acidic environment, a high turnover frequency (TOF) of ∼2.2 × 10–3 s–1 per Co atom was achieved, which is more than twice the TOF of traditional hard-templated, mesoporous Co3O4.
TL;DR: In this article, the authors show that small-scale turbulence alone does not produce a significant broadening of the cloud-droplet spectrum because of the smearing of droplet-scale fluctuations by rapid turbulent and gravitational mixing.
Abstract: Motivated by the need to resolve the condensation-coalescence bottleneck in warm rain formation, a significant number of studies have emerged in the past 15 years concerning the growth of cloud droplets by water-vapor diffusion and by collision-coalescence in a turbulent environment. With regard to condensation, recent studies suggest that small-scale turbulence alone does not produce a significant broadening of the cloud-droplet spectrum because of the smearing of droplet-scale fluctuations by rapid turbulent and gravitational mixing. However, different diffusional-growth histories associated with large-eddy hopping could lead to a significant spectral broadening. In contrast, small-scale turbulence in cumulus clouds makes a significant contribution to the collision-coalescence of droplets, enhancing the collection kernel up to a factor of 5, especially for droplet pairs with a low gravitational collision rate. This moderate level of enhancement has a significant impact on warm rain initiation. The multiscale nature of turbulent cloud microphysical processes and open research issues are delineated throughout.