Showing papers by "Boston College published in 2021"
18 Mar 2021
TL;DR: The authors describe how language used to communicate about autism within much of autism research can reflect and perpetuate ableist ideologies (i.e., beliefs and practices that discriminative of individuals with autism).
Abstract: In this commentary, we describe how language used to communicate about autism within much of autism research can reflect and perpetuate ableist ideologies (i.e., beliefs and practices that discrimi...
349 citations
TL;DR: In this paper, the authors present a detailed step-by-step guide on how to apply fuzzy-set Qualitative Comparative Analysis (fsQCA) in Information Systems and marketing.
313 citations
TL;DR: In this paper, the authors used high-resolution scanning tunnelling microscopy to discover an unconventional chiral charge order in a kagome material, KV3Sb5, with both a topological band structure and a superconducting ground state.
Abstract: Intertwining quantum order and non-trivial topology is at the frontier of condensed matter physics1–4. A charge-density-wave-like order with orbital currents has been proposed for achieving the quantum anomalous Hall effect5,6 in topological materials and for the hidden phase in cuprate high-temperature superconductors7,8. However, the experimental realization of such an order is challenging. Here we use high-resolution scanning tunnelling microscopy to discover an unconventional chiral charge order in a kagome material, KV3Sb5, with both a topological band structure and a superconducting ground state. Through both topography and spectroscopic imaging, we observe a robust 2 × 2 superlattice. Spectroscopically, an energy gap opens at the Fermi level, across which the 2 × 2 charge modulation exhibits an intensity reversal in real space, signalling charge ordering. At the impurity-pinning-free region, the strength of intrinsic charge modulations further exhibits chiral anisotropy with unusual magnetic field response. Theoretical analysis of our experiments suggests a tantalizing unconventional chiral charge density wave in the frustrated kagome lattice, which can not only lead to a large anomalous Hall effect with orbital magnetism, but also be a precursor of unconventional superconductivity. An unconventional chiral charge order is observed in a kagome superconductor by scanning tunnelling microscopy. This charge order has unusual magnetic tunability and intertwines with electronic topology.
275 citations
TL;DR: A review of the characterization methodologies used for enzyme/MOF-immobilized enzymes can be found in this article, where the authors discuss enzyme protection via encapsulation, pore infiltration and surface adsorption and summarizes strategies to form multicomponent composites.
Abstract: Because of their efficiency, selectivity, and environmental sustainability, there are significant opportunities for enzymes in chemical synthesis and biotechnology. However, as the three-dimensional active structure of enzymes is predominantly maintained by weaker noncovalent interactions, thermal, pH, and chemical stressors can modify or eliminate activity. Metal-organic frameworks (MOFs), which are extended porous network materials assembled by a bottom-up building block approach from metal-based nodes and organic linkers, can be used to afford protection to enzymes. The self-assembled structures of MOFs can be used to encase an enzyme in a process called encapsulation when the MOF is synthesized in the presence of the biomolecule. Alternatively, enzymes can be infiltrated into mesoporous MOF structures or surface bound via covalent or noncovalent processes. Integration of MOF materials and enzymes in this way affords protection and allows the enzyme to maintain activity in challenge conditions (e.g., denaturing agents, elevated temperature, non-native pH, and organic solvents). In addition to forming simple enzyme/MOF biocomposites, other materials can be introduced to the composites to improve recovery or facilitate advanced applications in sensing and fuel cell technology. This review canvasses enzyme protection via encapsulation, pore infiltration, and surface adsorption and summarizes strategies to form multicomponent composites. Also, given that enzyme/MOF biocomposites straddle materials chemistry and enzymology, this review provides an assessment of the characterization methodologies used for MOF-immobilized enzymes and identifies some key parameters to facilitate development of the field.
252 citations
TL;DR: In this paper, the authors reported the observation of bulk superconductivity in single crystals of the two-dimensional kagome metal (KV, Rb, Cs) with magnetic susceptibility, resistivity, and heat capacity measurements.
Abstract: Here we report the observation of bulk superconductivity in single crystals of the two-dimensional kagome metal ${\mathrm{KV}}_{3}{\mathrm{Sb}}_{5}$. Magnetic susceptibility, resistivity, and heat capacity measurements reveal superconductivity below ${T}_{c}=0.93\phantom{\rule{0.28em}{0ex}}\mathrm{K}$, and density functional theory (DFT) calculations further characterize the normal state as a ${\mathbb{Z}}_{2}$ topological metal. Our results demonstrate that the recent observation of superconductivity within the related kagome metal ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ is likely a common feature across the $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ ($A$: K, Rb, Cs) family of compounds and establishes them as a rich arena for studying the interplay between bulk superconductivity, topological surface states, and likely electronic density wave order in an exfoliable kagome lattice.
242 citations
TL;DR: The authors found that literacy interventions help audiences to be “inoculated” against any fake news, which is not the case in many forms of media literacy interventions, such as education.
Abstract: Concerns over fake news have triggered a renewed interest in various forms of media literacy. Prevailing expectations posit that literacy interventions help audiences to be “inoculated” against any...
226 citations
23 Apr 2021
TL;DR: Internationalization as a concept and strategic agenda is a relatively new, broad, and varied phenomenon in tertiary education as mentioned in this paper, and during the past half-century, internationalization has evolved from a...
Abstract: Internationalization as a concept and strategic agenda is a relatively new, broad, and varied phenomenon in tertiary education. During the past half-century, internationalization has evolved from a...
202 citations
TL;DR: In this article, the authors investigated the electronic and structural properties of charge density wave (CDW) by first-principles calculations and revealed an inverse Star of David deformation as the $2\ifmmode\times\else\texttimes\fi{}2
Abstract: Kagome metals $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ ($A=\mathrm{K}$, Rb, and Cs) exhibit intriguing superconductivity below $0.9\ensuremath{\sim}2.5\text{ }\text{ }\mathrm{K}$, a charge density wave (CDW) transition around $80\ensuremath{\sim}100\text{ }\text{ }\mathrm{K}$, and ${\mathbb{Z}}_{2}$ topological surface states. The nature of the CDW phase and its relation to superconductivity remains elusive. In this work, we investigate the electronic and structural properties of CDW by first-principles calculations. We reveal an inverse Star of David deformation as the $2\ifmmode\times\else\texttimes\fi{}2\ifmmode\times\else\texttimes\fi{}2$ CDW ground state of the kagome lattice. The kagome lattice shows softening breathing-phonon modes, indicating the structural instability. However, electrons play an essential role in the CDW transition via Fermi surface nesting and van Hove singularity. The inverse Star of David structure agrees with recent experiments by scanning tunneling microscopy (STM). The CDW phase inherits the nontrivial ${\mathbb{Z}}_{2}$-type topological band structure. Further, we find that the electron-phonon coupling is too weak to account for the superconductivity ${T}_{c}$ in all three materials. It implies the existence of unconventional pairing of these kagome metals. Our results provide essential knowledge toward understanding the superconductivity and topology in kagome metals.
199 citations
TL;DR: In this paper, a temperature-dependent cascade of different symmetry-broken electronic states in a new kagome superconductor, CsV3Sb5, was discovered using spectroscopic imaging scanning tunnelling microscopy.
Abstract: The kagome lattice of transition metal atoms provides an exciting platform to study electronic correlations in the presence of geometric frustration and nontrivial band topology1–18, which continues to bear surprises. Here, using spectroscopic imaging scanning tunnelling microscopy, we discover a temperature-dependent cascade of different symmetry-broken electronic states in a new kagome superconductor, CsV3Sb5. We reveal, at a temperature far above the superconducting transition temperature Tc ~ 2.5 K, a tri-directional charge order with a 2a0 period that breaks the translation symmetry of the lattice. As the system is cooled down towards Tc, we observe a prominent V-shaped spectral gap opening at the Fermi level and an additional breaking of the six-fold rotational symmetry, which persists through the superconducting transition. This rotational symmetry breaking is observed as the emergence of an additional 4a0 unidirectional charge order and strongly anisotropic scattering in differential conductance maps. The latter can be directly attributed to the orbital-selective renormalization of the vanadium kagome bands. Our experiments reveal a complex landscape of electronic states that can coexist on a kagome lattice, and highlight intriguing parallels to high-Tc superconductors and twisted bilayer graphene. A study reveals a temperature-dependent cascade of different symmetry-broken electronic states in the kagome superconductor CsV3Sb5, and highlights intriguing parallels between vanadium-based kagome metals and materials exhibiting similar electronic phases.
168 citations
TL;DR: In this article, the authors show that the topological charge density wave phase in the quasi-2D Kagome superconductor AV3Sb5 is a chiral flux phase.
Abstract: We argue that the topological charge density wave phase in the quasi-2D Kagome superconductor AV3Sb5 is a chiral flux phase. Considering the symmetry of the Kagome lattice, we show that the chiral flux phase has the lowest energy among those states which exhibit 2 × 2 charge orders observed experimentally. This state breaks the time-reversal symmetry and displays anomalous Hall effect. The explicit pattern of the density of state in real space is calculated. These results are supported by recent experiments and suggest that these materials are new platforms to investigate the interplay between topology, superconductivity and electron–electron correlations.
154 citations
TL;DR: In this article, tensile-strained Mxene/carbon nanotube (CNT) porous microspheres were developed as an electrocatalyst for the lithium polysulfide (LiPS) redox reaction.
Abstract: Tensile-strained Mxene/carbon nanotube (CNT) porous microspheres were developed as an electrocatalyst for the lithium polysulfide (LiPS) redox reaction. The internal stress on the surface results in lattice distortion with expanding Ti-Ti bonds, endowing the Mxene nanosheet with abundant active sites and regulating the d-band center of Ti atoms upshifted closer to the Fermi level, leading to strengthened LiPS adsorbability and accelerated catalytic conversion. The macroporous framework offers uniformed sulfur distribution, potent sulfur immobilization, and large surface area. The composite interwoven by CNT tentacle enhances conductivity and prevents the restacking of Mxene sheets. This combination of tensile strain effect and hierarchical architecture design results in smooth and favorable trapping-diffusion-conversion of LiPS on the interface. The Li-S battery exhibits an initial capacity of 1451 mAh g-1 at 0.2 C, rate capability up to 8 C, and prolonged cycle life.
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TL;DR: In this paper, the authors used spectroscopic-imaging scanning tunneling microscopy to reveal a pronounced intensity anisotropy between different 2a0 charge density wave (CDW) directions in KV3Sb5.
Abstract: Recently discovered kagome superconductors AV3Sb5 (A=K, Rb, Cs) provide a fresh opportunity to realize and study correlation-driven electronic phenomena on a kagome lattice. The observation of a 2a0 by 2a0 charge density wave (CDW) in the normal state of all members of AV3Sb5 kagome family has generated an enormous amount of interest, in an effort to uncover the nature of this CDW state, and identify any "hidden" broken symmetries. We use spectroscopic-imaging scanning tunneling microscopy to reveal a pronounced intensity anisotropy between different 2a0 CDW directions in KV3Sb5. In particular, by examining the strength of ordering wave vectors as a function of energy in Fourier transforms of differential conductance maps, we find that one of the CDW directions is distinctly different compared to the other two. This observation points towards an intrinsic rotation symmetry broken electronic ground state, where the symmetry is reduced from C6 to C2. Furthermore, in contrast to previous reports, we find that the CDW phase is insensitive to magnetic field direction, regardless of the presence or absence of atomic defects. Our experiments, combined with earlier observations of a stripe 4a0 charge ordering in CsV3Sb5, establish correlation-driven rotation symmetry breaking as a unifying feature of AV3Sb5 kagome superconductors.
TL;DR: In this paper, a federated vehicular network (FVN) is proposed to support distributed machine learning and federated learning in vehicular networks with centralized components and utilizes both DSRC and mmWave communication to achieve scalable and stable performance.
Abstract: The emerging advances in personal devices and privacy concerns have given the rise to the concept of Federated Learning. Federated Learning proves its effectiveness and privacy preservation through collaborative local training and updating a shared machine learning model while protecting the individual data-sets. This article investigates a new type of vehicular network concept, namely a Federated Vehicular Network (FVN), which can be viewed as a robust distributed vehicular network. Compared to traditional vehicular networks, an FVN has centralized components and utilizes both DSRC and mmWave communication to achieve more scalable and stable performance. As a result, FVN can be used to support data-/computation-intensive applications such as distributed machine learning and Federated Learning. The article first outlines the enabling technologies of FVN. Then, we briefly discuss the high-level architecture of FVN and explain why such an architecture is adequate for Federated Learning. In addition, we use auxiliary Blockchain-based systems to facilitate transactions and mitigate malicious behaviors. Next, we discuss in detail one key component of FVN, a federated vehicular cloud (FVC), that is used for sharing data and models in FVN. In particular, we focus on the routing inside FVCs and present our solutions and preliminary evaluation results. Finally, we point out open problems and future research directions of this disruptive technology.
TL;DR: In this paper, the authors carried out muon spin relaxation and rotation measurements on the newly discovered kagome metal KV3Sb5, and found a local field dominated by weak magnetic disorder which they associate with the nuclear moments present, and a modest temperature dependence which tracks the bulk magnetic susceptibility.
Abstract: We have carried out muon spin relaxation and rotation measurements on the newly discovered kagome metal KV3Sb5, and find a local field dominated by weak magnetic disorder which we associate with the nuclear moments present, and a modest temperature dependence which tracks the bulk magnetic susceptibility. We find no evidence for the existence of V4+local moments, suggesting that the physics underlying the recently reported giant unconventional anomalous Hall effect in this material warrants further studies.
TL;DR: The current state of self-care research is addressed and an agenda for future research based on the inaugural conference of the International Center for Self-Care Research is proposed, which will lead a collaborative program of research that addressesSelf-care knowledge gaps and improves outcomes.
TL;DR: In this article, the authors examined the spatiotemporal evolution of bike-sharing usage across the COVID-19 pandemic and compared it with other modes of transport, finding that the proportion of commuting trips is substantially lower during the pandemic.
Harvard University1, University of California, Los Angeles2, Indian Institute of Technology Kanpur3, Northeastern University4, Southern University of Science and Technology5, Nanyang Technological University6, Boston College7, Max Planck Society8, National Cheng Kung University9, Tata Institute of Fundamental Research10, National Institute for Materials Science11, Academia Sinica12, National Taiwan University13, Massachusetts Institute of Technology14
TL;DR: In this paper, an even-layered, two-dimensional topological antiferromagnetic axion insulator has been studied, where spatial degrees of freedom correspond to different layers.
Abstract: Whereas ferromagnets have been known and used for millennia, antiferromagnets were only discovered in the 1930s1. At large scale, because of the absence of global magnetization, antiferromagnets may seem to behave like any non-magnetic material. At the microscopic level, however, the opposite alignment of spins forms a rich internal structure. In topological antiferromagnets, this internal structure leads to the possibility that the property known as the Berry phase can acquire distinct spatial textures2,3. Here we study this possibility in an antiferromagnetic axion insulator-even-layered, two-dimensional MnBi2Te4-in which spatial degrees of freedom correspond to different layers. We observe a type of Hall effect-the layer Hall effect-in which electrons from the top and bottom layers spontaneously deflect in opposite directions. Specifically, under zero electric field, even-layered MnBi2Te4 shows no anomalous Hall effect. However, applying an electric field leads to the emergence of a large, layer-polarized anomalous Hall effect of about 0.5e2/h (where e is the electron charge and h is Planck's constant). This layer Hall effect uncovers an unusual layer-locked Berry curvature, which serves to characterize the axion insulator state. Moreover, we find that the layer-locked Berry curvature can be manipulated by the axion field formed from the dot product of the electric and magnetic field vectors. Our results offer new pathways to detect and manipulate the internal spatial structure of fully compensated topological antiferromagnets4-9. The layer-locked Berry curvature represents a first step towards spatial engineering of the Berry phase through effects such as layer-specific moire potential.
TL;DR: This article analyzed a dataset of 2390 completed ICOs, which raised a total of $12 billion in capital, nearly all since January 2017, and found evidence of significant ICO underpricing, with average returns of 179% from the ICO price to the first day's opening market price, over a holding period that averages just 16 days.
Cambridge Health Alliance1, Harvard University2, City University of New York3, University of Miami4, Boston University5, Columbia University6, University of Texas at San Antonio7, Boston College8, University of California, San Francisco9, McMaster University10, University of California, Los Angeles11, University of London12, Tufts University13, University of Toronto14, Brigham and Women's Hospital15, New York University16, Icahn School of Medicine at Mount Sinai17, Cornell University18, University of Pennsylvania19
TL;DR: The report by the Lancet Commission on Public Policy and Health in the Trump Era assesses the repercussions of Donald Trump's health-related policies and examines the failures and social schisms that enabled his election as discussed by the authors, concluding that "low and middle-income white people's anger over their deteriorating life prospects to mobilise racial animus and xenophobia and enlist their support for policies that benefit high-income people and corporations and threaten health".
TL;DR: It is shown that tokens are likely to dominate equity for ventures developing goods or services that involve low marginal production costs, those for which entrepreneurial effort is crucial, and/or those with relatively low payoff volatility.
Abstract: This paper develops a theory of financing of entrepreneurial ventures via crypto tokens, which is not limited to platform-based ventures. We compare token financing with traditional equity financin...
TL;DR: It follows that unpredictable environments impose metabolic costs, and in social environments these costs can be reduced by conforming to others' expectations, and a formal model of this sense of should is developed, beginning from a minimal set of biological premises.
TL;DR: This article explored nursing students' perspectives about the effects of the COVID-19 pandemic on their education and intention to join the nursing workforce and highlighted the need to develop emergency education preparedness plans that address student wellbeing and novel collaborative partnerships between schools and clinical partners.
TL;DR: In this paper, an emergent conformal field theory was proposed for entanglement dynamics, whose critical exponents are beyond any known theory, and which implies a measurement-induced Bell-like nonlocality, where distant qubits become entangled with an infinite speed.
Abstract: Local measurements in random quantum circuits lead to a new class of ``entanglement phase transitions''. Through extensive calculations at the critical point of ``stabilizer'' circuits --- organized by a mapping from the finite rectangular geometry to the semi-infinite plane --- the authors find here an emergent conformal field theory description of the entanglement dynamics, whose critical exponents are beyond any known theory. As we show, conformal symmetry implies a measurement-induced Bell-like nonlocality, where distant qubits become entangled with an infinite speed.
TL;DR: The authors formulate a dynamic no-arbitrage asset pricing model for equities and corporate bonds, featuring time variation in both risk aversion and economic uncertainty, and show that the joint dynamics among cash flow...
Abstract: We formulate a dynamic no-arbitrage asset pricing model for equities and corporate bonds, featuring time variation in both risk aversion and economic uncertainty. The joint dynamics among cash flow...
TL;DR: This model provides a structure for anticipating research needs in response to the changing nature of work, including the formation of research priorities, the need for expanded research methods and measures, and attention to diverse populations of enterprises and workers.
Trinity College, Dublin1, University of Auckland2, Boston College3, Brigham Young University4, Brunel University London5, Universidad Iberoamericana Ciudad de México6, University of California, San Francisco7, RMIT University8, Nipissing University9, Ulster University10, Maynooth University11, University of Eastern Finland12, George Mason University13
TL;DR: In this paper, a cross-sectional online survey with 20,398 respondents from 101 different countries was conducted to understand the global risk factors that are associated with social isolation and loneliness, irrespective of culture or country.
Abstract: The COVID-19 global pandemic and subsequent public health social measures have challenged our social and economic life, with increasing concerns around potentially rising levels of social isolation and loneliness. This paper is based on cross-sectional online survey data (available in 10 languages, from 2 June to 16 November 2020) with 20,398 respondents from 101 different countries. It aims to help increase our understanding of the global risk factors that are associated with social isolation and loneliness, irrespective of culture or country, to support evidence-based policy, services and public health interventions. We found the prevalence of severe loneliness was 21% during COVID-19 with 6% retrospectively reporting severe loneliness prior to the pandemic. A fifth were defined as isolated based on their usual connections, with 13% reporting a substantial increase in isolation during COVID-19. Personal finances and mental health were overarching and consistently cross-cutting predictors of loneliness and social isolation, both before and during the pandemic. With the likelihood of future waves of COVID-19 and related restrictions, it must be a public health priority to address the root causes of loneliness and social isolation and, in particular, address the needs of specific groups such as carers or those living alone.
TL;DR: In this paper, the Solid Electrolyte Interphase (SEI) layer formed in carbonate-based and ether-based electrolyte was designed to increase the energy density of Li metal batteries.
TL;DR: In this article, a review summarizes the recent progress of various DPP-based organic small molecules on phototheranostics during the last five years, as well as their molecular structure design and their performance.
TL;DR: In this paper, the Big Five Questionnaire, the Interpersonal Reactivity Index and the Connectedness to Nature Scale were administered to 230 Italian workers and the results indicated that the relationship between the personality traits of agreeableness and openness and connectedness to nature is mediated by empathy, in particular by perspective taking and empathic concern.
Abstract: Given the relationship between attitudes and behaviors (Frymier and Nadler 2007), perceptions toward the environment are of concern in shaping environmental behaviors. Accordingly, understanding how to improve people’s connection to nature may be a vital research area linked to sustainability efforts. To further this understanding, the present study examined the contribution of empathy in mediating the relationship between personality traits and connectedness to nature. The Big Five Questionnaire, the Interpersonal Reactivity Index and the Connectedness to Nature Scale were administered to 230 Italian workers. The results indicated that the relationship between the personality traits of agreeableness and openness and connectedness to nature is mediated by empathy, in particular by perspective taking and empathic concern. Given that empathy is amenable to training, compared to more stable personality traits, the results suggest that empathy may be a promising area for further research and intervention with the goal of increasing connectedness to nature and valuing of the environment among adults in the workplace.
TL;DR: This review synthesizes the latest advances in the psychology behind consumption of luxury objects and experiences and proposes that the psychology of luxury consumption is governed by a set of tensions between what luxury means to the self and the external forces that define luxury consumption.
Abstract: This review synthesizes the latest advances in the psychology behind consumption of luxury objects and experiences to which people typically feel strongly attached. We discuss novel drivers, forms, and consequences of luxury consumption from recent research. We propose that the psychology of luxury consumption is governed by a set of tensions between what luxury means to the self and the external forces that define luxury consumption. These tensions shape consumer behavior, from the level of desire for luxury products and services, to the types of signals viewed as luxury and acquired and displayed as such, and to post-consumption consequences of consuming luxury. We discuss how this tension-based framework offers future opportunities for the study of the drivers, forms, and consequences of luxury consumption.