Digital Commons Network^™

Transcranial Electrical Stimulation Accelerates Human Sleep Homeostasis, Davide Reato, Fernando Gasca, Abhishek Datta, Marom Bikson, Lisa Marshall, Lucas C. Parra

Publications and Research

The sleeping brain exhibits characteristic slow-wave activity which decays over the course of the night. This decay is thought to result from homeostatic synaptic downscaling. Transcranial electrical stimulation can entrain slow-wave oscillations (SWO) in the human electro-encephalogram (EEG). A computational model of the underlying mechanism predicts that firing rates are predominantly increased during stimulation. Assuming that synaptic homeostasis is driven by average firing rates, we expected an acceleration of synaptic downscaling during stimulation, which is compensated by a reduced drive after stimulation. We show that 25 minutes of transcranial electrical stimulation, as predicted, reduced the decay of SWO in the …

Allometric Scaling And Resource Limitations Model Of Tree Heights: Part 1. Model Optimization And Testing Over Continental Usa, Yuli Shi, Sungho Choi, Xiliang Ni, Sangram Ganguly, Gong Zhang, Hieu V. Duong, Michael A. Lefsky, Marc Simard, Sassan S. Saatchi, Shihyan Lee, Wenge Ni-Meister, Shilong Piao, Chunxiang Cao, Ramakrishna R. Nemani, Ranga B. Myneni

Publications and Research

A methodology to generate spatially continuous fields of tree heights with an optimized Allometric Scaling and Resource Limitations (ASRL) model is reported in this first of a multi-part series of articles. Model optimization is performed with the Geoscience Laser Altimeter System (GLAS) waveform data. This methodology is demonstrated by mapping tree heights over forested lands in the continental USA (CONUS) at 1 km spatial resolution. The study area is divided into 841 eco-climatic zones based on three forest types, annual total precipitation classes (30 mm intervals) and annual average temperature classes (2 °C intervals). Three model parameters (area of single …

Estimation Of Total Body Skeletal Muscle Mass In Chinese Adults: Prediction Model By Dual-Energy X-Ray Absorptiometry, Xinyu Zhao, Zimian Wang, Junyi Zhang, Jianming Hua, Wei He, Shankuan Zhu

Publications and Research

Background: There are few reports on total body skeletal muscle mass (SM) in Chinese. The objective of this study is to establish a prediction model of SM for Chinese adults.

Methodology: Appendicular lean soft tissue (ALST) was measured by dual energy X-ray absorptiometry (DXA) and SM by magnetic resonance image (MRI) in 66 Chinese adults (52 men and 14 women). Images of MRI were segmented into compartments including intermuscular adipose tissue (IMAT) and IMAT-free SM. Regression was used to fit the prediction model SM~czk|ALST. Age and gender were adjusted in the fitted model. The piece-wise linear function was performed to …

From Toxic Tours To Growing The Grassroots: Tensions In Critical Pedagogy And Community Development, Celina Su, Isabelle Jagninski

Publications and Research

Structural inequalities in American public education are inextricably tied to deep-seated patterns of racial and economic segregation. Children in poor neighborhoods are less likely to have the household resources, neighborhood institutions, or school amenities necessary for a good, challenging education. In response, a growing number of organizations have launched initiatives to simultaneously revitalize neighborhoods and improve public education, emphasizing youth participation as an essential component in their efforts. We draw upon ethnographic data from two such organizations to examine their practice of place-based critical pedagogy in community development. We focus on how they engage marginalized, “hard-to-reach” youth via (1) experiential …

Generalized Least-Squares Regressions Ii: Theory And Classification, Nataniel Greene

Publications and Research

In the first paper of this series, a variety of known and new symmetric and weighted least-squares regression methods were presented with efficient derivations. This paper continues and generalizes the previous work with a theory for deriving, analyzing, and classifying all symmetric and weighted least-squares regression methods.

Spaces Speak, Are You Listening?: Experiencing Aural Architecture, Gordon Alley-Young

Publications and Research

No abstract provided.

Winsor & Newton Original Handbooks: Asurface-Enhanced Raman Scattering (Sers) Andraman Spectral Database Of Dyes From Modernwatercolor Pigments, Federica Pozzi, John R. Lombardi, Marco Leona

Publications and Research

Background

Winsor & Newton Ltd. has been one of the main fine art products providers since its establishment in 1832, being responsible for the manufacture of a wide assortment of materials ranging from oils and pigments to brushes and papers. All the items produced over the years have been indexed in a comprehensive historical archive. Original Winsor & Newton handbooks are a powerful resource which can offer insight into the world of artists’ materials, and knowledge of artists’ choices through the identification of substances employed to obtain particular colors. Scientific analyses of various kinds have been carried out on Winsor …

16 Things Every Defense Attorney Should Know About Fair Cross-Section Challenges, Nina Chernoff, Joseph B. Kadane

Publications and Research

No abstract provided.

Sustainability An Issue That Crosses Many Areas, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Mather Explains The Known And Unknown Universe, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Generalized Least-Squares Regressions I: Efficient Derivations, Nataniel Greene

Publications and Research

Ordinary least-squares regression suffers from a fundamental lack of symmetry: the regression line of y given x and the regression line of x given y are not inverses of each other. Alternative symmetric regression methods have been developed to address this concern, notably: orthogonal regression and geometric mean regression. This paper presents in detail a variety of least squares regression methods which may not have been known or fully explicated. The derivation of each method is made efficient through the use of Ehrenberg's formula for the ordinary least-squares error and through the extraction of a weight function g(b) which characterizes …

Adoption Of Short Message Service: Gender Difference, Chulsung Kim, Dong-Gook Kim, Chongwoo Park

Publications and Research

While the adoption of mobile devices has recently received research attention, there has been little research focusing on a specific application or service running in mobile devices. In this study, we examine the adoption of short message service (SMS) with the technology acceptance model. The model has been assessed with the data collected from 225 SMS users. Results from the partial least squares analysis show that perceived ease of use of SMS positively affects perceived usefulness of SMS and intention to adopt SMS, and perceived usefulness of SMS also positively affects intention to adopt SMS. Comparing the two factors, perceived …

Cft Representation Of Interacting Bulk Gauge Fields In Ads, Daniel N. Kabat, Gilad Lifschytz

Publications and Research

We develop the representation of interacting bulk gauge fields and charged scalar matter in AdS in terms of non-local observables in the dual CFT. We work in holographic gauge in the bulk, A_z = 0. The correct statement of micro-causality in holographic gauge is somewhat subtle, so we first discuss it from the bulk point of view. We then show that in the 1/N expansion CFT correlators can be lifted to obtain bulk correlation functions which satisfy micro-causality. This requires adding an infinite tower of higher-dimension multi-trace operators to the CFT definition of a bulk observable. For conserved currents the …

‘What’S In The Niddk Cdr?’—Public Query Tools For The Niddk Central Data Repository, Huaqin Pan, Mary-Anne Ardini, Vesselina Bakalov, Michael Delatte, Paul Eggers, Laxminarayana Ganapathi, Craig R. Hollingsworth, Joshua Levy, Sheping Li, Joseph Pratt, Norma Pugh, Ying Qin, Rebekah Rasooly, Helen Ray, Jean E. Richardson, Amanda Flynn Riley, Susan M. Rogers, Sylvia Tan, Charles F. Turner, Stacie White, Philip C. Cooley

Publications and Research

The National Institute of Diabetes and Digestive Disease (NIDDK) Central Data Repository (CDR) is a web-enabled resource available to researchers and the general public. The CDR warehouses clinical data and study documentation from NIDDK funded research, including such landmark studies as The Diabetes Control and Complications Trial (DCCT, 1983–93) and the Epidemiology of Diabetes Interventions and Complications (EDIC, 1994–present) follow-up study which has been ongoing for more than 20 years. The CDR also houses data from over 7 million biospecimens representing 2 million subjects. To help users explore the vast amount of data stored in the NIDDK CDR, we developed …

On The Nonsymmetric Longer Queue Model: Joint Distribution, Asymptotic Properties, And Heavy Traffic Limits, Charles Knessl, Haishen Yao

Publications and Research

We consider two parallel queues, each with independent Poisson arrival rates, that are tended by a single server. The exponential server devotes all of its capacity to the longer of the queues. If both queues are of equal length, the server devotes of its capacity to the first queue and the remaining to the second. We obtain exact integral representations for the joint probability distribution of the number of customers in this two-node network. Then we evaluate this distribution in various asymptotic limits, such as large numbers of customers in either/both of the queues, light traffic where arrivals are infrequent, …

Stratigraphic Constraints On Groundwater Flow: Examples From York College, Cuny Campus In Queens, New York City, Nazrul I. Khandaker, Stanley Schleifer, Ezazul Haque, Coreyn Goddard, Shirley Jackson

Publications and Research

Surficial geology of the York College campus is dominated by recent glacial deposits dating back to late Wisconsinan event. Several shallow excavation-type trenches reaching a depth of approximately 6 to 10 feet were dug in the wide greeneries adjacent to the parking lot to determine soil texture and collect in-situ permeability data. Based on these shallow pits, an apparent subsurface stratigraphy has been constructed. In general, the uppermost 8 to 18 inches is mostly clayey-and-silty sand and organic-rich top soil overlying stratified drift. The uppermost horizons are observed to also contain fill materials such as bricks, concretes, broken glasses, and …

Landau-Zener Dynamics Of A Nanoresonator Containing A Tunneling Spin, Michael F. O'Keeffe, Eugene M. Chudnovsky, Dmitry A. Garanin

Publications and Research

We study the Landau-Zener dynamics of a tunneling spin coupled to a torsional resonator. For strong spin-phonon coupling, when the oscillator frequency is large compared to the tunnel splitting, the system exhibits multiple Landau-Zener transitions. Entanglement of spin and mechanical angular momentum results in abrupt changes of oscillator dynamics which coincide in time with spin transitions. We show that a large number of spins on a single oscillator coupled only through the in-phase phonon field behaves as a single large spin, greatly enhancing the spin-phonon coupling. We compare purely quantum and semiclassical dynamics of the system and discuss their experimental …

Quantum Dynamics Of Vortices In Mesoscopic Magnetic Disks, Ricardo Zarzuela, Eugene M. Chudnovsky, J M. Hernandez, J Tajeda

Publications and Research

Model of quantum depinning of magnetic vortex cores from line defects in a disk geometry and under the application of an in-plane magnetic field has been developed within the framework of the Caldeira-Leggett theory. The corresponding instanton solutions are computed for several values of the magnetic field. Expressions for the crossover temperature Tc and for the depinning rate \Gamma(T) are obtained. Fitting of the theory parameters to experimental data is also presented.

Reversal Of Magnetization Of A Single-Domain Magnetic Particle By The Ac Field Of Time-Dependent Frequency, Liufei Cai, Dmitry A. Garanin, Eugene M. Chudnovsky

Publications and Research

We report numerical and analytical studies of the reversal of the magnetic moment of a single- domain magnetic particle by a circularly polarized ac field of time-dependent frequency. For the time-linear frequency sweep, the phase diagrams are computed that illustrate the dependence of the reversal on the frequency sweep rate v , the amplitude of the ac field h , the magnetic anisotropy field d , and the damping parameter . It is shown that the most efficient magnetization reversal requires a non-linear time dependence of the frequency, ! ( t ) , for which an exact analytical formula is …

Black Hole Formation At The Correspondence Point, Norihiro Izuka, Daniel N. Kabat, Roy Shubho, Debajyoti Sarkar

Publications and Research

We study the process of bound state formation in a D-brane collision. We consider two mechanisms for bound state formation. The first, operative at weak coupling in the worldvolume gauge theory, is pair creation of W-bosons. The second, operative at strong coupling, corresponds to formation of a large black hole in the dual supergravity. These two processes agree qualitatively at intermediate coupling, in accord with the correspondence principle of Horowitz and Polchinski. We show that the size of the bound state and timescale for formation of a bound state agree at the correspondence point. The timescale involves matching a parametric …

Mutual Information In Hawking Radiation, Norihiro Izuka, Daniel N. Kabat

Publications and Research

We compute the mutual information of two Hawking particles emitted consecutively by an evaporating black hole. Following Page, we find that the mutual information is of order exp(-S) where S is the entropy of the black hole. We speculate on implications for black hole unitarity, in particular on a possible failure of locality at large distances.

Diffractive Effects And General Boundary Conditions In Casimir Energy, Dimitra Karabali, V P. Nair

Publications and Research

The effect of edges and apertures on the Casimir energy of an arrangement of plates and boundaries can be calculated in terms of an effective nonlocal lower-dimensional field theory that lives on the boundary. This formalism has been developed in a number of previous papers and applied to specific examples with Dirichlet boundary conditions. Here we generalize the formalism to arbitrary boundary conditions. As a specific example, the geometry of a flat plate and a half-plate placed parallel to it is considered for a number of different boundary conditions and the area-dependent and edge dependent contributions to the Casimir energy …

Macintyre And The Emotivists, James E. Mahon

Publications and Research

This chapter both explains the origins of emotivism in C. K. Ogden and I. A. Richards, R. B. Braithwaite, Austin Duncan-Jones, A. J. Ayer and Charles Stevenson (along with the endorsement by Frank P. Ramsey, and the summary of C. D. Broad), and looks at Alasdair MacIntyre's criticisms of emotivism as the inevitable result of Moore's attack on naturalistic ethics and his ushering in the fact/value distinction, which was a historical product of the Enlightenment.

Black Hole Formation In Fuzzy Sphere Collapse, Norihiro Izuka, Daniel N. Kabat, Roy Shubho, Debajyoti Sarkar

Publications and Research

We study the collapse of a fuzzy sphere, that is a spherical membrane built out of D0-branes, in the BFSS model. At weak coupling, as the sphere shrinks, open strings are produced. If the initial radius is large then open string production is not important and the sphere behaves classically. At intermediate initial radius the back-reaction from open string production is important but the fuzzy sphere retains its identity. At small initial radius the sphere collapses to form a black hole. The crossover between the later two regimes is smooth and occurs at the correspondence point of Horowitz and Polchinski.

On Three Dimensions As The Preferred Dimensionality Of Space Via The Brandenberger-Vafa Mechanism, Brian Greene, Daniel N. Kabat, Stefanos Marnerides

Publications and Research

In previous work it was shown that, in accord with the Brandenberger-Vafa mechanism, three is the maximum number of spatial dimensions that can grow large cosmologically from an initial thermal fluctuation. Here we complement that work by considering the possibility of successive fluctuations. Suppose an initial fluctuation causes at least one dimension to grow, and suppose successive fluctuations occur on timescales of order alpha'^{1/2}. If the string coupling is sufficiently large, we show that such fluctuations are likely to push a three-dimensional subspace to large volume where winding modes annihilate. In this setting three is the preferred number of large …

Excitation Modes Of Vortices In Submicron Magnetic Disks, Ricardo Zarzuela, Eugene M. Chudnovsky, Javier Tejada

Publications and Research

Classical and quantum theory of spin waves in the vortex state of a mesoscopic sub-micron magnetic disk has been developed with account of the finite mass density of the vortex. Oscillations of the vortex core resemble oscillations of a charged string in a potential well in the presence of the magnetic field. Conventional gyroscopic frequency appears as a gap in the spectrum of spin waves of the vortex. The mass of the vortex has been computed that agrees with experimental findings. Finite vortex mass generates a high-frequency branch of spin waves. Effects of the external magnetic field and dissipation have …

Turbulent Fronts Of Quantum Detonation In Molecular Magnets, Dmitry A. Garanin

Publications and Research

Dipolar-controlled quantum deflagration going over into quantum detonation in the elongated Mn_12 Ac molecular magnet in a strong transverse field has been considered within the full 3d model. It is shown that within the dipolar window around tunneling resonances the deflagration front is non-flat. With increasing bias, dipolar instability makes the front turbulent, while its speed reaches sonic values, that is a signature of detonation.

Superconductivity In An Inhomogeneous Bundle Of Metallic And Semiconducting Nanotubes, Ilya Grigorenko, Anvar Zakhidov

Publications and Research

Using Bogoliubov-de Gennes formalism for inhomogeneous systems, we have studied superconducting properties of a bundle of packed carbon nanotubes, making a triangular lattice in the bundle's transverse cross-section. The bundle consists of a mixture of metallic and doped semiconducting nanotubes, which have different critical transition temperatures. We investigate how a spatially averaged superconducting order parameter and the critical transition temperature depend on the fraction of the doped semiconducting carbon nanotubes in the bundle. Our simulations suggest that the superconductivity in the bundle will be suppressed when the fraction of the doped semiconducting carbon nanotubes will be less than 0.5, which …

Technology Innovations In Publishing: New Directions In Academic And Cultural Communication., Elisabeth Tappeiner, Kate Lyons

Publications and Research

Over time, publishing technologies have not only influenced how people read, but also how knowledge is evaluated and authority is established. Social and mobile technologies represent relatively recent developments that have transformed the trade publishing world, but the extent to which they have affected academic publishing remains an open question. This article examines the rapid and disruptive transformations in the trade and digital publishing world, discusses how these developments have already intersected with the work of academics and considers how these changes might continue to transform the dissemination of academic research in the future.

Positioning Library Data For The Semantic Web: Recent Developments In Resource Description, Kimmy Szeto

Publications and Research

Recent developments in resource description standards and technologies have aimed at moving cataloging practice to the web environment and making library data available for exchange and reuse on the Semantic Web. As the library community looks outward and forward, library standards and technologies are converging with Web practices in three areas: content description, data models, and data exchange. This article captures the essence of the core standards and technologies that underlie the daily work of practitioners of library service, including Resource Description and Access (RDA), Functional Requirements for Bibliographic Records (FRBR), the Linked Data environment, Resource Description Framework (RDF), and …