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Showing papers by "University of Arkansas published in 2017"


Journal ArticleDOI
TL;DR: In this mini review, the current management principles, including the spectrum of medications that are currently used for pharmacologic management, for lowering the elevated blood glucose in T2DM are outlined.
Abstract: Type 2 diabetes mellitus (T2DM) is a global pandemic, as evident from the global cartographic picture of diabetes by the International Diabetes Federation (http://www.diabetesatlas.org/). Diabetes mellitus is a chronic, progressive, incompletely understood metabolic condition chiefly characterized by hyperglycemia. Impaired insulin secretion, resistance to tissue actions of insulin, or a combination of both are thought to be the commonest reasons contributing to the pathophysiology of T2DM, a spectrum of disease originally arising from tissue insulin resistance and gradually progressing to a state characterized by complete loss of secretory activity of the beta cells of the pancreas. T2DM is a major contributor to the very large rise in the rate of non-communicable diseases affecting developed as well as developing nations. In this mini review, we endeavor to outline the current management principles, including the spectrum of medications that are currently used for pharmacologic management, for lowering the elevated blood glucose in T2DM.

841 citations


Journal ArticleDOI
TL;DR: Propensity score matching (PSM) has become a popular technique for estimating average treatment effects (ATEs) in accounting research as mentioned in this paper, however, studies often oversell the capabilities of PSM, fail to disclose important design choices and/or implement PSM in a theoretically inconsistent manner.
Abstract: Propensity score matching (PSM) has become a popular technique for estimating average treatment effects (ATEs) in accounting research. In this study, we discuss the usefulness and limitations of PSM relative to more traditional multiple regression (MR) analysis. We discuss several PSM design choices and review the use of PSM in 86 articles in leading accounting journals from 2008–2014. We document a significant increase in the use of PSM from zero studies in 2008 to 26 studies in 2014. However, studies often oversell the capabilities of PSM, fail to disclose important design choices, and/or implement PSM in a theoretically inconsistent manner. We then empirically illustrate complications associated with PSM in three accounting research settings. We first demonstrate that when the treatment is not binary, PSM tends to confine analyses to a subsample of observations where the effect size is likely to be smallest. We also show that seemingly innocuous design choices greatly influence sample composi...

673 citations


Journal ArticleDOI
TL;DR: The authors examines whether one popular Internet data souring trend is a good fit for social science disciplines, including advertising, and examines whether it can be used in the context of data collection using Internet based samples.
Abstract: Data collection using Internet-based samples has become increasingly popular in many social science disciplines, including advertising. This research examines whether one popular Internet data sour...

623 citations


Journal ArticleDOI
TL;DR: Results show that while 'health' is a major consumer motive, a broad diversity of drivers influence the clean label trend with particular relevance of intrinsic or extrinsic product characteristics and socio-cultural factors, however, 'free from' artificial additives/ingredients food products tend to differ from organic and natural products.

557 citations


Journal ArticleDOI
TL;DR: This work reports on synapses based on ferroelectric tunnel junctions and shows that STDP can be harnessed from inhomogeneous polarization switching and demonstrates that conductance variations can be modelled by the nucleation-dominated reversal of domains.
Abstract: In the brain, learning is achieved through the ability of synapses to reconfigure the strength by which they connect neurons (synaptic plasticity). In promising solid-state synapses called memristors, conductance can be finely tuned by voltage pulses and set to evolve according to a biological learning rule called spike-timing-dependent plasticity (STDP). Future neuromorphic architectures will comprise billions of such nanosynapses, which require a clear understanding of the physical mechanisms responsible for plasticity. Here we report on synapses based on ferroelectric tunnel junctions and show that STDP can be harnessed from inhomogeneous polarization switching. Through combined scanning probe imaging, electrical transport and atomic-scale molecular dynamics, we demonstrate that conductance variations can be modelled by the nucleation-dominated reversal of domains. Based on this physical model, our simulations show that arrays of ferroelectric nanosynapses can autonomously learn to recognize patterns in a predictable way, opening the path towards unsupervised learning in spiking neural networks.

410 citations


Journal ArticleDOI
Maxime Cailleret1, Steven Jansen2, Elisabeth M. R. Robert3, Elisabeth M. R. Robert4, Lucía DeSoto5, Tuomas Aakala6, Joseph A. Antos7, Barbara Beikircher8, Christof Bigler1, Harald Bugmann1, Marco Caccianiga9, Vojtěch Čada10, J. Julio Camarero11, Paolo Cherubini12, Hervé Cochard13, Marie R. Coyea14, Katarina Čufar15, Adrian J. Das16, Hendrik Davi13, Sylvain Delzon13, Michael Dorman17, Guillermo Gea-Izquierdo18, Sten Gillner19, Sten Gillner20, Laurel J. Haavik21, Laurel J. Haavik22, Henrik Hartmann23, Ana-Maria Hereş24, Kevin R. Hultine25, Pavel Janda10, Jeffrey M. Kane26, Vyacheslav I. Kharuk27, Thomas Kitzberger28, Thomas Kitzberger29, Tamir Klein30, Koen Kramer31, Frederic Lens32, Tom Levanič, Juan Carlos Linares Calderón33, Francisco Lloret34, Raquel Lobo-do-Vale35, Fabio Lombardi36, Rosana López Rodríguez37, Rosana López Rodríguez38, Harri Mäkinen, Stefan Mayr8, Ilona Mészáros39, Juha M. Metsaranta40, Francesco Minunno6, Walter Oberhuber8, Andreas Papadopoulos41, Mikko Peltoniemi, Any Mary Petritan12, Brigitte Rohner1, Brigitte Rohner12, Gabriel Sangüesa-Barreda11, Dimitrios Sarris42, Dimitrios Sarris43, Dimitrios Sarris44, Jeremy M. Smith45, Amanda B. Stan46, Frank J. Sterck31, Dejan Stojanović47, Maria Laura Suarez28, Miroslav Svoboda10, Roberto Tognetti48, José M. Torres-Ruiz13, Volodymyr Trotsiuk10, Ricardo Villalba28, Floor Vodde49, Alana R. Westwood50, Peter H. Wyckoff51, Nikolay Zafirov52, Jordi Martínez-Vilalta34 
ETH Zurich1, University of Ulm2, Vrije Universiteit Brussel3, Royal Museum for Central Africa4, University of Coimbra5, University of Helsinki6, University of Victoria7, University of Innsbruck8, University of Milan9, Czech University of Life Sciences Prague10, Spanish National Research Council11, Swiss Federal Institute for Forest, Snow and Landscape Research12, Institut national de la recherche agronomique13, Laval University14, University of Ljubljana15, United States Geological Survey16, Ben-Gurion University of the Negev17, Center for International Forestry Research18, Technical University of Berlin19, Dresden University of Technology20, University of Kansas21, University of Arkansas22, Max Planck Society23, National Museum of Natural History24, Desert Botanical Garden25, Humboldt State University26, Sukachev Institute of Forest27, National Scientific and Technical Research Council28, National University of Comahue29, Agricultural Research Organization, Volcani Center30, Wageningen University and Research Centre31, Naturalis32, Pablo de Olavide University33, Autonomous University of Barcelona34, University of Lisbon35, Mediterranean University36, University of Western Sydney37, Technical University of Madrid38, University of Debrecen39, Natural Resources Canada40, American Hotel & Lodging Educational Institute41, Open University of Cyprus42, University of Patras43, University of Cyprus44, University of Colorado Boulder45, Northern Arizona University46, University of Novi Sad47, European Forest Institute48, Estonian University of Life Sciences49, University of Alberta50, University of Minnesota51, University of Forestry, Sofia52
TL;DR: The results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or bark-beetle outbreaks.
Abstract: Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-conti- nental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca. 84% of the mortality events. The extent and duration of these reductions were highly variable (1–100 years in 96% of events) due to the complex interactions among study species and the source(s) of mortality. Strong and long-lasting declines were found for gymnosperms, shade- and drought-tolerant species, and trees that died from competition. Angiosperms and trees that died due to biotic attacks (especially bark-beetles) typically showed relatively small and short-term growth reductions. Our analysis did not highlight any universal trade-off between early growth and tree longevity within a species, although this result may also reflect high variability in sampling design among sites. The intersite and interspecific variability in growth patterns before mortality provides valuable information on the nature of the mortality process, which is consistent with our understanding of the physiological mechanisms leading to mortality. Abrupt changes in growth immediately before death can be associated with generalized hydraulic failure and/or bark-beetle attack, while long-term decrease in growth may be associated with a gradual decline in hydraulic performance coupled with depletion in carbon reserves. Our results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or bark-beetle outbreaks.

367 citations


Journal ArticleDOI
TL;DR: This review presents the state of the art in strain and ripple-induced effects on the electronic and optical properties of graphene by providing the crystallographic description of mechanical deformations, as well as the diffraction pattern for different kinds of representative deformation fields.
Abstract: This review presents the state of the art in strain and ripple-induced effects on the electronic and optical properties of graphene. It starts by providing the crystallographic description of mechanical deformations, as well as the diffraction pattern for different kinds of representative deformation fields. Then, the focus turns to the unique elastic properties of graphene, and to how strain is produced. Thereafter, various theoretical approaches used to study the electronic properties of strained graphene are examined, discussing the advantages of each. These approaches provide a platform to describe exotic properties, such as a fractal spectrum related with quasicrystals, a mixed Dirac-Schrodinger behavior, emergent gravity, topological insulator states, in molecular graphene and other 2D discrete lattices. The physical consequences of strain on the optical properties are reviewed next, with a focus on the Raman spectrum. At the same time, recent advances to tune the optical conductivity of graphene by strain engineering are given, which open new paths in device applications. Finally, a brief review of strain effects in multilayered graphene and other promising 2D materials like silicene and materials based on other group-IV elements, phosphorene, dichalcogenide- and monochalcogenide-monolayers is presented, with a brief discussion of interplays among strain, thermal effects, and illumination in the latter material family.

358 citations


Journal ArticleDOI
TL;DR: The zeptolitre sensing volume of bilayer-coated solid-state nanopores can be used to determine the approximate shape, volume, charge, rotational diffusion coefficient and dipole moment of individual proteins.
Abstract: Established methods for characterizing proteins typically require physical or chemical modification steps or cannot be used to examine individual molecules in solution. Ionic current measurements through electrolyte-filled nanopores can characterize single native proteins in an aqueous environment, but currently offer only limited capabilities. Here we show that the zeptolitre sensing volume of bilayer-coated solid-state nanopores can be used to determine the approximate shape, volume, charge, rotational diffusion coefficient and dipole moment of individual proteins. To do this, we developed a theory for the quantitative understanding of modulations in ionic current that arise from the rotational dynamics of single proteins as they move through the electric field inside the nanopore. The approach allows us to measure the five parameters simultaneously, and we show that they can be used to identify, characterize and quantify proteins and protein complexes with potential implications for structural biology, proteomics, biomarker detection and routine protein analysis.

352 citations


Journal ArticleDOI
TL;DR: An overview on the recent progress of high concentration electrolytes in different battery chemistries is provided and the formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally distinct from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes.
Abstract: The electrolyte is an indispensable component in all electrochemical energy storage and conversion devices with batteries being a prime example. While most research efforts have been pursued on the materials side, the progress for the electrolyte is slow due to the decomposition of salts and solvents at low potentials, not to mention their complicated interactions with the electrode materials. The general properties of bulk electrolytes such as ionic conductivity, viscosity, and stability all affect the cell performance. However, for a specific electrochemical cell in which the cathode, anode, and electrolyte are optimized, it is the interface between the solid electrode and the liquid electrolyte, generally referred to as the solid electrolyte interphase (SEI), that dictates the rate of ion flow in the system. The commonly used electrolyte is within the range of 1-1.2 m based on the prior optimization experience, leaving the high concentration region insufficiently recognized. Recently, electrolytes with increased concentration (>1.0 m) have received intensive attention due to quite a few interesting discoveries in cells containing concentrated electrolytes. The formation mechanism and the nature of the SEI layers derived from concentrated electrolytes could be fundamentally distinct from those of the traditional SEI and thus enable unusual functions that cannot be realized using regular electrolytes. In this article, we provide an overview on the recent progress of high concentration electrolytes in different battery chemistries. The experimentally observed phenomena and their underlying fundamental mechanisms are discussed. New insights and perspectives are proposed to inspire more revolutionary solutions to address the interfacial challenges.

329 citations


Journal ArticleDOI
TL;DR: It is suggested that multilayered M-MoS2-H2O system with ion accessible large nanochannels and efficient charge transport provide an efficient energy storage strategy for ultrafast supercapacitors.
Abstract: MoS2 is a promising electrode material for energy storage. However, the intrinsic multilayer pure metallic MoS2 (M-MoS2) has not been investigated for use in supercapacitors. Here, an ultrafast rate supercapacitor with extraordinary capacitance using a multilayer M-MoS2–H2O system is first investigated. Intrinsic M-MoS2 with a monolayer of water molecules covering both sides of nanosheets is obtained through a hydrothermal method with water as solvent. The super electrical conductivity of the as-prepared pure M-MoS2 is beneficial to electron transport for high power supercapacitor. Meanwhile, nanochannels between the layers of M-MoS2–H2O with a distance of ∼1.18 nm are favorable for increasing the specific space for ion diffusion and enlarging the surface area for ion adsorption. By virtue of this, M-MoS2–H2O reaches a high capacitance of 380 F/g at a scan rate of 5 mV/s and still maintains 105 F/g at scan rate of 10 V/s. Furthermore, the specific capacitance of the symmetric supercapacitor based on M-MoS...

312 citations


Journal ArticleDOI
TL;DR: In this paper, the authors argue that HRM practices can contribute to a firm's sustainable competitive advantage not only by enhancing employees' ability, and offering motivation and opportunities, but also by shaping supply-side and demand-side mobility constraints.
Abstract: The resource-based view (RBV) of the firm has been consistently used as a backdrop in strategic human resource management (SHRM) research and has the potential to bridge the ‘micro–macro’ divide. The tension between the SHRM and the strategic human capital literature, however, signifies that RBV has not reached its potential. In this paper, we begin with a brief review of the conceptual logic linking human resource management (HRM) practices and firm outcomes that aim at highlighting the different treatment of RBV in the SHRM and strategic human capital literatures. We then propose a conceptual model that suggests that HRM practices are not simple levers that enable firms to create sustainable competitive advantage, as most of the strategic human capital research postulates. On the contrary, we argue that HRM practices can contribute to a firm's sustainable competitive advantage not only by enhancing employees' ability, and offering motivation and opportunities, but also by shaping supply-side and demand-side mobility constraints.

Journal ArticleDOI
TL;DR: The development of THz PCA technology through the last 30 years is reviewed, the key modalities of improving device performance are identified, and literature is reviewed to summarize the progress made in these areas.
Abstract: Photoconductive antennas (PCAs) have been extensively utilized for the generation and detection of both pulsed broadband and single frequency continuous wave terahertz (THz) band radiation. These devices form the basis of many THz imaging and spectroscopy systems, which have demonstrated promising applications in various industries and research fields. The development of THz PCA technology through the last 30 years is reviewed. The key modalities of improving device performance are identified, and literature is reviewed to summarize the progress made in these areas. The goal of this review is to provide a collection of all relevant literature to bring researchers up to date on the current state and remaining challenges of THz PCA technology.

Journal ArticleDOI
03 Mar 2017-Science
TL;DR: It is reported that aspects of precipitation and potential evapotranspiration, along with the North Atlantic Oscillation, predicted variation in selection across plant and animal populations throughout many terrestrial biomes, whereas temperature explained little variation.
Abstract: Climate change has the potential to affect the ecology and evolution of every species on Earth. Although the ecological consequences of climate change are increasingly well documented, the effects of climate on the key evolutionary process driving adaptation—natural selection—are largely unknown. We report that aspects of precipitation and potential evapotranspiration, along with the North Atlantic Oscillation, predicted variation in selection across plant and animal populations throughout many terrestrial biomes, whereas temperature explained little variation. By showing that selection was influenced by climate variation, our results indicate that climate change may cause widespread alterations in selection regimes, potentially shifting evolutionary trajectories at a global scale.

Journal ArticleDOI
TL;DR: 2D InP3 exhibits extraordinary optical absorption with significant excitonic effects in the entire range of the visible light spectrum and suggests tunable magnetism and half-metallicity under hole doping or defect engineering, which is attributed to the novel Mexican-hat-like bands and van Hove singularities in its electronic structure.
Abstract: Atomically thin two-dimensional (2D) materials have received considerable research interest due to their extraordinary properties and promising applications. Here we predict the monolayered indium triphosphide (InP3) as a new semiconducting 2D material with a range of favorable functional properties by means of ab initio calculations. The 2D InP3 crystal shows high stability and promise of experimental synthesis. It possesses an indirect band gap of 1.14 eV and a high electron mobility of 1919 cm2 V-1 s-1, which can be strongly manipulated with applied strain. Remarkably, the InP3 monolayer suggests tunable magnetism and half-metallicity under hole doping or defect engineering, which is attributed to the novel Mexican-hat-like bands and van Hove singularities in its electronic structure. A semiconductor-metal transition is also revealed by doping 2D InP3 with electrons. Furthermore, monolayered InP3 exhibits extraordinary optical absorption with significant excitonic effects in the entire range of the visible light spectrum. All these desired properties render 2D InP3 a promising candidate for future applications in a wide variety of technologies, in particular for electronic, spintronic, and photovoltaic devices.

Journal ArticleDOI
TL;DR: This statement updates practical recommendations regarding fluid-replacement strategies for physically active individuals and educates physically active people regarding the benefits of fluid replacement to promote performance and safety and the potential risks of both hypohydration and hyperhydration on health and physical performance.
Abstract: Objective: To present evidence-based recommendations that promote optimized fluid-maintenance practices for physically active individuals. Background: Both a lack of adequate fluid replacement (h...

Journal ArticleDOI
TL;DR: A review of the applications, benefits, and limitations of deep learning vis-a-vis physical robotic systems, using contemporary research as exemplars, is presented in this paper, which is intended to communicate recent advances to the wider robotics community and inspire additional interest in and application of deep Learning in robotics.
Abstract: Advances in deep learning over the last decade have led to a flurry of research in the application of deep artificial neural networks to robotic systems, with at least 30 papers published on the subject between 2014 and the present. This review discusses the applications, benefits, and limitations of deep learning vis-a-vis physical robotic systems, using contemporary research as exemplars. It is intended to communicate recent advances to the wider robotics community and inspire additional interest in and application of deep learning in robotics.

Journal ArticleDOI
TL;DR: Given the empirical support for the one-in-five statistic, it is suggested that the controversy occurs because of misunderstandings about studies’ methods and results and because this topic has implications for gender relations, power, and sexuality.
Abstract: In 2014, U.S. president Barack Obama announced a White House Task Force to Protect Students From Sexual Assault, noting that “1 in 5 women on college campuses has been sexually assaulted during the...

Journal ArticleDOI
TL;DR: This paper proposes a Continuous Approximation model that designs the potentiality of drones as a mode of transportation to supply emergency commodities in a disaster-affected region and conducts extensive sensitivity analysis to reveal insights into how system design varies with key drone design parameters.

Journal ArticleDOI
TL;DR: In this article, a comprehensive performance set of biomarkers should include key markers of nutrition and metabolic health, hydration status, muscle status, endurance performance, injury status and risk, and inflammation.
Abstract: Biomarker discovery and validation is a critical aim of the medical and scientific community. Research into exercise and diet-related biomarkers aims to improve health, performance, and recovery in military personnel, athletes, and lay persons. Exercise physiology research has identified individual biomarkers for assessing health, performance, and recovery during exercise training. However, there are few recommendations for biomarker panels for tracking changes in individuals participating in physical activity and exercise training programs. Our approach was to review the current literature and recommend a collection of validated biomarkers in key categories of health, performance, and recovery that could be used for this purpose. We determined that a comprehensive performance set of biomarkers should include key markers of (a) nutrition and metabolic health, (b) hydration status, (c) muscle status, (d) endurance performance, (e) injury status and risk, and (f) inflammation. Our review will help coaches, clinical sport professionals, researchers, and athletes better understand how to comprehensively monitor physiologic changes, as they design training cycles that elicit maximal improvements in performance while minimizing overtraining and injury risk.

Journal ArticleDOI
23 Nov 2017
TL;DR: In this article, the authors provide a review of the state-of-the-art advanced module packaging technologies for SiC devices with the focus on module layout, packaging material system, and module integration trend, and link these packaging advancements to their impacts on the SiC device performances.
Abstract: Silicon-Carbide (SiC) devices with superior performance over traditional silicon power devices have become the prime candidates for future high-performance power electronics energy conversion. Traditional device packaging becomes a limiting factor in fully realizing the benefits offered by SiC power devices, and thus, improved and advanced packaging structures are required to bridge the gap between SiC devices and their applications. This paper provides a review of the state-of-art advanced module packaging technologies for SiC devices with the focuses on module layout, packaging material system, and module integration trend, and links these packaging advancements to their impacts on the SiC device performances. Through this review, the paper discusses main challenges and potential solutions for SiC modules, which is critical for future SiC applications.

Journal ArticleDOI
TL;DR: In this article, a preliminary analysis of the effects of Facebook usage by undergraduate students at Lulea University of Technology in Sweden is presented. Andersen et al. proposed a research model to test the effect of social media usage on students' academic performance.
Abstract: Introduction: The paper provides a preliminary analysis of the effects of Facebook usage by undergraduate students at Lulea University of Technology in Sweden. The proposed research model tests the ...

Journal ArticleDOI
TL;DR: Phage-assisted continuous evolution selections are designed to rapidly produce highly active and selective orthogonal AARSs with high activity and amino acid specificity and the capability of PACE is established to efficiently evolve orthogsonal Aarss withHigh activity and Amino acid specificity.
Abstract: Directed evolution of orthogonal aminoacyl-tRNA synthetases (AARSs) enables site-specific installation of noncanonical amino acids (ncAAs) into proteins. Traditional evolution techniques typically produce AARSs with greatly reduced activity and selectivity compared to their wild-type counterparts. We designed phage-assisted continuous evolution (PACE) selections to rapidly produce highly active and selective orthogonal AARSs through hundreds of generations of evolution. PACE of a chimeric Methanosarcina spp. pyrrolysyl-tRNA synthetase (PylRS) improved its enzymatic efficiency (kcat/KMtRNA) 45-fold compared to the parent enzyme. Transplantation of the evolved mutations into other PylRS-derived synthetases improved yields of proteins containing noncanonical residues up to 9.7-fold. Simultaneous positive and negative selection PACE over 48 h greatly improved the selectivity of a promiscuous Methanocaldococcus jannaschii tyrosyl-tRNA synthetase variant for site-specific incorporation of p-iodo-L-phenylalanine. These findings offer new AARSs that increase the utility of orthogonal translation systems and establish the capability of PACE to efficiently evolve orthogonal AARSs with high activity and amino acid specificity.

Posted Content
TL;DR: In this paper, an energy harvesting sensor continuously monitors a system and sends time-stamped status updates to a destination, where the destination keeps track of the system status through the received updates.
Abstract: In this paper, we consider a scenario where an energy harvesting sensor continuously monitors a system and sends time-stamped status updates to a destination. The destination keeps track of the system status through the received updates. We use the metric Age of Information (AoI), the time that has elapsed since the last received update was generated, to measure the "freshness" of the status information available at the destination. We assume energy arrives randomly at the sensor according to a Poisson process, and each status update consumes one unit of energy. Our objective is to design optimal online status update policies to minimize the long-term average AoI, subject to the energy causality constraint at the sensor. We consider three scenarios, i.e., the battery size is infinite, finite, and one unit only, respectively. For the infinite battery scenario, we adopt a best-effort uniform status update policy and show that it minimizes the long-term average AoI. For the finite battery scenario, we adopt an energy-aware adaptive status update policy, and prove that it is asymptotically optimal when the battery size goes to infinity. For the last scenario where the battery size is one, we first show that within a broadly defined class of online policies, the optimal policy should have a renewal structure, i.e., the status update epochs form a renewal process, and the length of each renewal interval depends on the first energy arrival over that interval only. We then focus on a renewal interval, and prove that if the AoI in the system is below a threshold when the first energy arrives, the sensor should store the energy and hold status update until the AoI reaches the threshold, otherwise, it updates the status immediately. We analytically characterize the long-term average AoI under such a threshold-based policy, and explicitly identify the optimal threshold.

Journal ArticleDOI
TL;DR: In this article, a straightforward approach is proposed to induce the growth of detrimental dendritic Li so the cells are “shorted” frequently and consistently, based on this new protocol, various electrolytes are revisited and the SEI derived are compared and quantified, providing new insights for addressing the challenges in rechargeable Li metal battery technologies.

Journal ArticleDOI
TL;DR: To determine if mitochondrial degeneration precedes cancer‐induced muscle wasting in tumour‐bearing mice, a large number of mice were sacrificed to study the role of mitochondria in cancer cachexia.
Abstract: Background Cancer cachexia is largely irreversible, at least via nutritional means, and responsible for 20–40% of cancer-related deaths. Therefore, preventive measures are of primary importance; however, little is known about muscle perturbations prior to onset of cachexia. Cancer cachexia is associated with mitochondrial degeneration; yet, it remains to be determined if mitochondrial degeneration precedes muscle wasting in cancer cachexia. Therefore, our purpose was to determine if mitochondrial degeneration precedes cancer-induced muscle wasting in tumour-bearing mice. Methods First, weight-stable (MinStable) and cachectic (MinCC) ApcMin/+ mice were compared with C57Bl6/J controls for mRNA contents of mitochondrial quality regulators in quadriceps muscle. Next, Lewis lung carcinoma (LLC) cells or PBS (control) were injected into the hind flank of C57Bl6/J mice at 8 week age, and tumour allowed to develop for 1, 2, 3, or 4 weeks to examine time course of cachectic development. Succinate dehydrogenase stain was used to measure oxidative phenotype in tibialis anterior muscle. Mitochondrial quality and function were assessed using the reporter MitoTimer by transfection to flexor digitorum brevis and mitochondrial function/ROS emission in permeabilized adult myofibres from plantaris. RT-qPCR and immunoblot measured the expression of mitochondrial quality control and antioxidant proteins. Data were analysed by one-way ANOVA with Student–Newman–Kuels post hoc test. Results MinStable mice displayed ~50% lower Pgc-1α, Pparα, and Mfn2 compared with C57Bl6/J controls, whereas MinCC exhibited 10-fold greater Bnip3 content compared with C57Bl6/J controls. In LLC, cachectic muscle loss was evident only at 4 weeks post-tumour implantation. Oxidative capacity and mitochondrial content decreased by ~40% 4 weeks post-tumour implantation. Mitochondrial function decreased by ~25% by 3 weeks after tumour implantation. Mitochondrial degeneration was evident by 2 week LLC compared with PBS control, indicated by MitoTimer red/green ratio and number of pure red puncta. Mitochondrial ROS production was elevated by ~50 to ~100% when compared with PBS at 1–3 weeks post-tumour implantation. Mitochondrial quality control was dysregulated throughout the progression of cancer cachexia in tumour-bearing mice. In contrast, antioxidant proteins were not altered in cachectic muscle wasting. Conclusions Functional mitochondrial degeneration is evident in LLC tumour-bearing mice prior to muscle atrophy. Contents of mitochondrial quality regulators across ApcMin/+ and LLC mice suggest impaired mitochondrial quality control as a commonality among pre-clinical models of cancer cachexia. Our data provide novel evidence for impaired mitochondrial health prior to cachectic muscle loss and provide a potential therapeutic target to prevent cancer cachexia.

Journal ArticleDOI
TL;DR: In this article, a survey aimed at summarizing the recent efforts in addressing electrocatalytic issues involved in hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) activities using 2D MoS2 materials.
Abstract: Two-dimensional (2D) layered molybdenum disulfide (MoS2) materials have attracted a wide range of attention due to their unique physical and chemical properties as well as their tunable electronic structures. Nowadays, hydrogen evolution reaction (HER) in water splitting is crucial to the cost-effective production of the pure hydrogen fuel, while oxygen reduction reaction (ORR) in fuel cells has been suffering from sluggish reaction kinetics even if a high loading of platinum is applied. In this context, it is of great urgency to develop new catalysts comparable to traditional noble metal catalysts in electrocatalytic activity but composed of earth-abundant elements. In the past decade, 2D layered MoS2-based materials have demonstrated great potential as non-noble metal catalysts for both HER and ORR to meet the two aforementioned requirements. To this end, we conduct this survey aimed at summarizing the recent efforts in addressing electrocatalytic issues involved in HER and ORR activities using 2D MoS2 materials. Starting from an introduction on the superiorities of MoS2-based electrocatalysts for HER and ORR in this review, we then discuss the critical obstacles faced by MoS2 nanosheets with respect to their catalytic activities. Subsequently, we summarize the recent strategies for improving the catalytic activity of MoS2-based materials and the updated advances. In the end, we suggest potential pathways for high-catalytic performance comparable to those of their noble-metal counterparts and give some perspectives on practical applications of MoS2-based materials in the future. The insightful views from this review are believed to be greatly beneficial for accomplishing a better understanding on 2D layered MoS2-based material catalysts in electrocatalytic activities.

Journal ArticleDOI
TL;DR: In this article, a comprehensive review of molecular and atomic layer deposition (MLD) processes for organic and organic-inorganic materials is presented, covering precursors, surface chemistry, growth characteristics, film properties, and promising applications.
Abstract: It has been a strong desire for researchers to control material growth at the molecular and atomic levels. Molecular and atomic layer deposition (MLD and ALD) are two such techniques. In comparison to a huge amount of studies invested on ALD, the research on MLD is still relatively limited due to the difficulty in finding suitable coupling precursors, but the recently successful applications of MLD are very encouraging in many areas such as surface engineering, new energies, and catalysis. In order to further stimulate more research enthusiasm and educate beginners, we contribute this thorough survey on the progress of MLD. This review is a comprehensive account of MLD processes for organic and organic–inorganic materials, covering precursors, surface chemistry, growth characteristics, film properties, and promising applications. The work provides a complete summary of over 80 MLD processes for growing over 20 types of pure polymeric and metal-based hybrid polymeric materials. Given their similarities in mechanisms, we made a comparative description between ALD and MLD, and discussed the uncountable possibilities to combine both ALD and MLD for advanced materials with desirable properties. To feature and highlight the significance of MLD, this review specially gives some detailed discussions on MLD's applications in several important areas, including novel nanostructured materials, surface engineering, new energies (i.e., batteries, supercapacitors, solar cells, and water splitting), catalysis, and rewritable data storage. With this work, we expect to boost research interest and attempts at advanced materials using MLD as well as ALD.

Journal ArticleDOI
01 Mar 2017
TL;DR: A model that posits 2 determinants (i.e., social influence and facilitating conditions) of BE and 4 moderators of the relationship between BE and its determinants, and argues that the cognitions underlying the formation of BI and BE differ.
Abstract: Research on information technology IT adoption and use, one of the most mature streams of research in the information science and information systems literature, is primarily based on the intentionality framework. Behavioral intention BI to use an IT is considered the sole proximal determinant of IT adoption and use. Recently, researchers have discussed the limitations of BI and argued that behavioral expectation BE would be a better predictor of IT use. However, without a theoretical and empirical understanding of the determinants of BE, we remain limited in our comprehension of what factors promote greater IT use in organizations. Using the unified theory of acceptance and use of technology as the theoretical framework, we develop a model that posits 2 determinants i.e., social influence and facilitating conditions of BE and 4 moderators i.e., gender, age, experience, and voluntariness of use of the relationship between BE and its determinants. We argue that the cognitions underlying the formation of BI and BE differ. We found strong support for the proposed model in a longitudinal field study of 321 users of a new IT. We offer theoretical and practical IT implications of our findings.

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TL;DR: This review focuses on the use of two-photon excited fluorescence and NAD(P)H fluorescence lifetime techniques in cancer, neuroscience, tissue engineering, and other biomedical applications over the last 5 years.
Abstract: Significance: Optical imaging using the endogenous fluorescence of metabolic cofactors has enabled nondestructive examination of dynamic changes in cell and tissue function both in vitro and in vivo. Quantifying NAD(P)H and FAD fluorescence through an optical redox ratio and fluorescence lifetime imaging (FLIM) provides sensitivity to the relative balance between oxidative phosphorylation and glucose catabolism. Since its introduction decades ago, the use of NAD(P)H imaging has expanded to include applications involving almost every major tissue type and a variety of pathologies. Recent Advances: This review focuses on the use of two-photon excited fluorescence and NAD(P)H fluorescence lifetime techniques in cancer, neuroscience, tissue engineering, and other biomedical applications over the last 5 years. In a variety of cancer models, NAD(P)H fluorescence intensity and lifetime measurements demonstrate a sensitivity to the Warburg effect, suggesting potential for early detection or high-throughp...

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TL;DR: The authors identify and then investigate empirical support for three theoretically-grounded perspectives on diaspora institution emergence and importance: instrumentally rational states tapping resources of emigrants and their descendants; value-rational states embracing lost members of the nation-state; institutionally-converging states governing diasporas consistent with global norms.
Abstract: Why do states establish and empower diaspora engagement institutions? Origin-state institutions dedicated to emigrants and their descendants have been largely overlooked in mainstream political studies, perhaps because they fall in the grey area between domestic politics and international relations. Now, diaspora institutions are found in over half of all United Nations member states, yet we have little theory and broad-sample statistical evidence to guide our understanding about when they are more likely to emerge and increase in importance. In response, we identify and then investigate empirical support for three theoretically-grounded perspectives on diaspora institution emergence and importance: instrumentally rational states tapping resources of emigrants and their descendants; value-rational states embracing lost members of the nation-state; institutionally-converging states governing diasporas consistent with global norms. We document support for these alternative perspectives in regression and related analyses modelling diaspora institution emergence and importance in 144 states observed from 1990-2010. Tapping perspective estimations exhibit better overall model fit compared to estimations based on other perspectives. Estimations combining perspectives exhibit the best model fit. Individual terms exhibiting signs contrary to prediction suggest new directions for theoretical and empirical research from different perspectives. We advance international relations research by identifying, distinguishing and testing alternative perspectives explaining diaspora institution emergence and importance. We also advance international relations practice and policy with evidence-guided insight on near-term trends in institution emergence and importance.