cssi/SciSciGPT-SciSciNet huggingface dataset:
Universality in few-body systems

Low-energy universality in atomic few-body systems as a result of a large two-body scattering length has gained a lot of attention recently. Here, I discuss recent progress in describing the three-body recombination of cold atoms in terms of a finite set of universal scaling functions and review results for the recombination length of 133Cs atoms obtained with these functions. Furthermore, I will consider the inclusion of effective range corrections and the relevance for further calculations in atomic and nuclear physics.
Density Fluctuations in MHD Turbulence: Spectra, Intermittency and Topology

We perform three-dimensional (3D) compressible MHD simulations over many dynamical times for an extended range of sonic and Alfven Mach numbers and analyze the statistics of 3D density and 2D column density, which include probability distribution functions, spectra, skewness, kurtosis, She-Leveque exponents, and genus. In order to establish the relation between the statistics of the observables, i.e., column densities, and the underlying 3D statistics of density, we analyze the effects of cloud boundaries. We define the parameter space for 3D measures to be recovered from column densities. In addition, we show that for subsonic turbulence the spectra of density fluctuations are consistent with k-7/3 in the case of a strong magnetic field and k-5/3 in the case of a weak magnetic field. For supersonic turbulence we confirm the earlier findings of the shallow spectra of density and Kolmogorov spectra of the logarithm of density. We find that the intermittencies of the density and velocity are very different.
Analysis of gradient descent learning algorithms for multilayer feedforward neural networks

Certain dynamical properties of gradient-type learning algorithms as they apply to multilayer feedforward neural networks are investigated. These properties are more related to the multilayer structure of the net than to the particular threshold units at the nodes. The analysis explains the empirical observation that the weight sequence generated by backpropagation and related stochastic gradient algorithms exhibits a long-term dependence on the initial choice of weights, and also a continued growth and/or drift long after the outputs have converged. The analysis is carried out in two steps. First, a simplified deterministic algorithm is derived using a describing function-type approach. Next, an analysis of the simplified algorithm is performed by considering an associated ordinary differential equation (ODE). Some numerical examples are given to illustrate the analysis. The dynamical behavior of backpropagation and related algorithms for the training of multilayer nets is discussed. >
Liquids: The Holy Grail of Microfluidics Modeling

Interest in microelectromechanical systems (MEMS) has experienced explosive growth during the past few years. Such small devices typically have characteristic size ranging from 1 mm down to 1 micron, and may include sensors, actuators, motors, pumps, turbines, gears, ducts and valves. Microdevices often involve mass, momentum and energy transport.Modeling gas and liquid flows through MEMS may necessitate including slip, rarefaction, compressibility, intermolecular forces and other unconventional effects. The continuum-based Navier-Stokes equations with either the traditional no-slip or slip-flow boundary conditions work only for a limited range of Knudsen numbers above which alternative models must be sought. These include molecular dynamics simulations (MD), Boltzmann equation, Direct Simulation Monte Carlo (DSMC), and other deterministic/probabilistic molecular models. The kinetic theory of gases defines well the boundaries for which the no-slip Navier-Stokes equations can accurately model the flow of a dilute gas. The same cannot be said about dense-gas and liquid flows where intermolecular interactions play a dominant role. Neither type of fluid has a well-advanced molecular-based theory, as is the case for dilute gases. The concept of mean free path is not very useful for liquids and the conditions under which a liquid flow fails to be in quasi-equilibrium state are not well defined. Such complex fluids can only be treated via hybrid continuum-molecular approaches, which approaches are still far from satisfactory at the present time. The present talk will address such issues and outline a blueprint for future developments.
In-network leader selection for acyclic graphs

We study the problem of leader selection in leader-follower multi-agent systems that are subject to stochastic disturbances. This problem arises in applications such as vehicle formation control, distributed clock synchronization, and distributed localization in sensor networks. We pose a new leader selection problem called the in-network leader selection problem. Initially, an arbitrary node is selected to be a leader, and in all consequent steps the network must have exactly one leader. The agents must collaborate to find the leader that minimizes the variance of the deviation from the desired trajectory, and they must do so within the network using only communication between neighbors. To develop a solution for this problem, we first show a connection between the leader selection problem and a class of discrete facility location problems. We then leverage a previously proposed self-stabilizing facility location algorithm to develop a self-stabilizing in-network leader selection algorithm for acyclic graphs.
Ekman pumping in compact astrophysical bodies

We examine the dynamics of a rotating viscous fluid following an abrupt change in the angular velocity of the solid bounding surface. We include the effects of a density stratification and compressibility which are important in astrophysical objects such as neutron stars. We confirm and extend the conclusions of previous studies that stratification restricts the Ekman pumping process to a relatively thin layer near the boundary, leaving much of the interior fluid unaffected. We find that finite compressibility further inhibits Ekman pumping by decreasing the extent of the pumped layer and by increasing the time for spin-up. The results of this paper are important for interpreting the spin period discontinuities (‘glitches’) observed in rotating neutron stars.
Wnt signaling and the polarity of the primary body axis.

How animals establish and pattern the primary body axis is one of the most fundamental problems in biology. Data from diverse deuterostomes (frog, fish, mouse, and amphioxus) and from planarians (protostomes) suggest that Wnt signaling through β-catenin controls posterior identity during body plan formation in most bilaterally symmetric animals. Wnt signaling also influences primary axis polarity of pre-bilaterian animals, indicating that an axial patterning role for Wnt signaling predates the evolution of bilaterally symmetric animals. The use of posterior Wnt signaling and anterior Wnt inhibition might be a unifying principle of body plan development in most animals.
Trading Equity for Efficiency in Environmental Protection? Environmental Justice Effects from the SO2 Allowance Trading Program*

Objective. Arthur Okun made plain the fundamental conflict between efficiency and equity that arises in the pursuit of policy goals (Okun, 1974). Although Okun was speaking about government tax and spending policy, the potential conflict between efficiency and equity is also manifest at the nexus of two of the most far-reaching changes in the environmental policy arena: the adoption of market-like tools for pollution control and the quest for environmental justice. The article assesses this potential tradeoff by determining whether the pursuit of efficiency through the Clean Air Act Amendment's (CAA) sulfur dioxide allowance trading program (ATP) inadvertently transfers pollution into poor and minority communities. Methods. I employ Probit, Tobit, and GLS models using data for all SO2 trading activity between January 1995 and March 2009 to estimate whether allowance trading concentrates SO2 emissions in poor communities and communities of color. When using these models, I control for sample selectivity and for possible bias stemming from the modifiable areal unit problem. Results. The ATP does not concentrate sulfur dioxide emissions in black or Hispanic communities. To the contrary, communities with high percentages of black and Hispanic residents experience fewer imports of sulfur dioxide. Allowance trading does transfer SO2 emissions into poorly educated communities. Conclusions. There is no inherent tradeoff between efficiency and equity when using market-based instruments for pollution control. Policymakers, however, might make an effort to design and implement future emissions trading programs in a manner that reduces the monitoring costs of tracking emissions trading. By reducing monitoring costs, policymakers may prevent the concentration of emissions in poorly educated communities while preserving the efficiency benefits of these instruments.
Integrated Genomic Profiling, Therapy Response, and Survival in Adult Acute Myelogenous Leukemia

Purpose: Recurrent gene mutations, chromosomal translocations, and acquired genomic copy number aberrations (aCNA) have been variously associated with acute myelogenous leukemia (AML) patient outcome. However, knowledge of the co-occurrence of such lesions and the relative influence of different types of genomic alterations on clinical outcomes in AML is still evolving. Experimental Design: We performed SNP 6.0 array-based genomic profiling of aCNA/copy neutral loss-of-heterozygosity (cnLOH) along with sequence analysis of 13 commonly mutated genes on purified leukemic blast DNA from 156 prospectively enrolled non-FAB-M3 AML patients across the clinical spectrum of de novo , secondary, and therapy-related AML. Results: TP53 and RUNX1 mutations are strongly associated with the presence of SNP-A–based aCNA/cnLOH, while FLT3 and NPM1 mutations are strongly associated with the absence of aCNA/cnLOH. The presence of mutations in RUNX1 , ASXL1 , and TP53 , elevated SNP-A–based genomic complexity, and specific recurrent aCNAs predicted failure to achieve a complete response to induction chemotherapy. The presence of ≥1 aCNA/cnLOH and higher thresholds predicted for poor long-term survival irrespective of TP53 status, and the presence of ≥1 aCNA/cnLOH added negative prognostic information to knowledge of mutations in TET2 , IDH1 , NPM1 , DNMT3A , and RUNX1 . Results of multivariate analyses support a dominant role for TP53 mutations and a role for elevated genomic complexity as predictors of short survival in AML. Conclusions: Integrated genomic profiling of a clinically relevant adult AML cohort identified genomic aberrations most associated with SNP-A–based genomic complexity, resistance to intensive induction therapies, and shortened overall survival. Identifying SNP-A–based lesions adds prognostic value to the status of several recurrently mutated genes. Clin Cancer Res; 1–12. ©2015 AACR.
Semantic middleware for e-Science knowledge spaces

The Tupelo semantic content management middleware implements Knowledge Spaces that enable scientists to integrate information into a comprehensive research record as they work with existing tools and domain-specific applications. Knowledge Spaces combine approaches that have demonstrated success in automating parts of this integration activity, including content management systems for domain-neutral management of data, workflow technologies for management of computation and analysis, and semantic web technologies for extensible, portable, citable management of descriptive information and other metadata. Tupelo's ‘Context’ facility and its associated semantic operations both allow existing data representations and tools to be plugged in, and also provide a semantic ‘glue’ of important associative relationships that span the research record, such as provenance, social networks, and annotation. Tupelo has enabled the recent work creating e-Science cyberenvironments to serve distributed, active scientific communities, allowing researchers to develop, coordinate and share datasets, documents, and computational models, while preserving process documentation and other contextual information needed to produce an integrated research record suitable for distribution and archiving. Copyright © 2011 John Wiley & Sons, Ltd.
Web banking in USA

This report presents a survey on North American banks Web sites carried out in October 1997. It was done in order to learn about Web banking models that are being adopted in the United States. We see American banks using the Web to reach opportunities in three different categories: to market information, to deliver banking products and services and to improve customer relationship. We split each one of these categories in three levels of interaction, to classify different kinds of applications that are found in each of the searched Web sites.
What's the Use? Welfare Estimates from Revealed Preference Models When Weak Complementarity Does Not Hold

Abstract In this paper we consider the theoretical and empirical ramifications of welfare measurement in revealed preference models when weak complementarity does not hold. In the context of a Kuhn–Tucker model of recreation demand we show that, while it is possible to estimate preferences that do not appear to exhibit weak complementarity, the calculation of welfare measurements from these models requires a cardinal interpretation of preferences that cannot be tested. Furthermore, we reiterate the under-appreciated fact that even traditional use value estimates require a cardinal restriction on preferences that, while often intuitive, also cannot be tested. We demonstrate empirically that the choice of restrictions can have significant ramifications, as use value estimates can vary based on the assumed preference structure.
Input to interaction to instruction: three key shifts in the history of child language research

In the early years of the Journal of Child Language, there was considerable disagreement about the role of language input or adult–child interaction in children's language acquisition. The view that quantity and quality of input to language-learning children is relevant to their language development has now become widely accepted as a principle guiding advice to parents and the design of early childhood education programs, even if it is not yet uncontested in the field of language development. The focus on variation in the language input to children acquires particular educational relevance when we consider variation in access to academic language – features of language particularly valued in school and related to success in reading and writing. Just as many children benefit from language environments that are intentionally designed to ensure adequate quantity and quality of input, even more probably need explicit instruction in the features of language that characterize its use for academic purposes
Enhancing performance of geographically distributed teams through targeted use of information and communication technologies

Increasingly, geographically dispersed teams are relying exclusively on sophisticated information and communication technologies (ICTs) to coordinate their knowledge. Current research argues that the reliance on the technology (versus face-to-face) for communication may inhibit geographically distributed team performance. In contrast, we argue that previous research associates negative performance effects with the level or degree of exclusive reliance on ICT without regard to the specific form or ways in which team members use ICT. We hypothesize that teams will be more successful when they use ICT to specifically facilitate the situational awareness needs created by their teams’ composition and task. We studied 54 geographically dispersed teams that all relied exclusively on ICT (with minimal to no face-to-face interactions) for coordination in order to control for the effect of the level of reliance on ICTs. Our multi-source/multi-method study demonstrates that the form of use can have a positive associ...
Pattern recognition in retrosynthetic analysis : Snapshots in total synthesis

In this Perspective, the value of small molecule natural products (SMNPs) in the discovery of active biological agents is discussed. The usefulness of the natural products-based method of potential pharma discovery is much augmented by the capacities of chemical synthesis. The great advances in synthetic methodology allow for major editing of the natural product in the hopes of optimizing potency and therapeutic index. As a consequence of the enormous increase in the power of multistep chemical synthesis, one can now approach structures of previously impractical complexity. In constructing a plan for a multistep synthesis, two complementary thought styles are often encountered. One is the traditional and extremely powerful concept of prioritized strategic bond disconnections. The other, which we term “pattern recognition,” involves the identification of moieties within the target, which are associated with reliable chemistry, and can serve to facilitate progress to the target. Recognition of such targets ...
Differential Activity of Diethylstilbestrol versus Estradiol As Neonatal Endocrine Disruptors in the Female Hamster (Mesocricetus auratus) Reproductive Tract

The synthetic estrogen diethylstilbestrol (DES) is a potent neonatal endocrine disruptor in the hamster. To test the specificity of this phenomenon, newborn animals were treated with 100 microgram of either DES or the natural estrogen, estradiol-17beta (E2). Of the two, neonatal DES exposure caused greater morphological disruption throughout the female reproductive tract in prepubertal animals and in adults that either retained their ovaries or were ovariectomized and then given the same levels of chronic E2 stimulation. In the uterus, a characteristic histopathological profile, including enhancement of both hyperplastic and apoptotic activity, was initiated prepubertally and exclusively in the endometrial epithelial cell compartment from the neonatally DES-treated animals and then was promoted by E2 stimulation during adulthood. Interestingly, apoptotic activity was not detected in an area of endometrial epithelium that progressed to the neoplastic state in a DES-exposed animal. Lastly, chronic estrogen induction of lactoferrin was also restricted to the DES-exposed endometrium. We conclude that 1) DES is more active than E2 as a perinatal endocrine disruptor in the hamster and 2) this experimental system should be generally useful as a means to screen compounds for such activity and then probe their mechanism of action.
Lead Galliate Glasses

Glasses have been formed in the binary system PbO–Ga2O3 within the compositional range extending from 60 to 80 mol% PbO. These glasses exhibit infrared cutoff values near 7.75 μm. The glasses are orange-red as a result of a cutoff in visible transmission near 500 nm. The glass transformation temperature decreases with increasing PbO concentration, whereas the thermal-expansion coefficient and density increase with increasing PbO content. Glasses containing 70 to 75 mol% PbO are good glass formers, with little tendency to crystallize, and exhibit good weathering behavior on exposure to normal atmosphere.
Highly Enantioselective Pictet–Spengler Reactions with α-Ketoamide-Derived Ketimines: Access to an Unusual Class of Quaternary α-Amino Amides†

"Quat's" the story? N-Aryl amides are effective directing/activating groups for chlorosilane Lewis acids. This aspect has been exploited for the development of the first simple and general method for the highly enantioselective Pictet-Spengler reaction of ketimines derived from alpha-ketoamides leading to quaternary alpha-amino acid derivatives (see scheme).
Algebraic geometry of Gaussian Bayesian networks

Conditional independence models in the Gaussian case are algebraic varieties in the cone of positive definite covariance matrices. We study these varieties in the case of Bayesian networks, with a view towards generalizing the recursive factorization theorem to situations with hidden variables. In the case when the underlying graph is a tree, we show that the vanishing ideal of the model is generated by the conditional independence statements implied by graph. We also show that the ideal of any Bayesian network is homogeneous with respect to a multigrading induced by a collection of upstream random variables. This has a number of important consequences for hidden variable models. Finally, we relate the ideals of Bayesian networks to a number of classical constructions in algebraic geometry including toric degenerations of the Grassmannian, matrix Schubert varieties, and secant varieties.
Rare-event simulation and efficient discretization for the supremum of Gaussian random fields

In this paper we consider a classic problem concerning the high excursion probabilities of a Gaussian random field f living on a compact set T. We develop efficient computational methods for the tail probabilities P{supTf(t) > b}. For each positive e, we present Monte Carlo algorithms that run in constant time and compute the probabilities with relative error e for arbitrarily large b. The efficiency results are applicable to a large class of Holder continuous Gaussian random fields. Besides computations, the change of measure and its analysis techniques have several theoretical and practical indications in the asymptotic analysis of Gaussian random fields.
Bio-inspired pressure sensing for active yaw control of underwater vehicles

A towed underwater vehicle equipped with a bio-inspired artificial lateral line (ALL) was constructed and tested with the goal of active detection and correction of the vehicle's angle of attack. Preliminary experiments demonstrate that a low number of sensors are sufficient to enable the discrimination between different orientations, and that a basic proportional controller is capable of keeping the vehicle aligned with the direction of flow. We propose that a model based controller could be developed to improve system response. Toward this, we derive a vehicle model based on a first-order 3D Rankine Source Panel Method, which is shown to be competent in estimating the pressure field in the region of interest during motion at constant angles of attack, and during execution of dynamic maneuvers. To solve the inverse problem of estimating the vehicle orientation given specific pressure measurements, an Unscented Kalman Filter is developed around the model. It is shown to provide a close estimation of the vehicle state using experimentally collected pressure measurements. This demonstrates that an artificial lateral line is a promising technology for dynamically mediating the angle of a body relative to the oncoming flow.
Key Players and Their Role During Mitochondrial Iron–Sulfur Cluster Biosynthesis

Iron-sulfur clusters are multifaceted iron-containing cofactors coordinated and utilized by numerous proteins in nearly all biological systems. Fe-S-cluster-containing proteins help direct pathways essential for cell viability and participate in biological applications ranging from nucleotide biosynthesis and stability, protein translation, enzyme catalysis, and mitochondrial metabolism. Fe-S-containing proteins function by utilizing the unique electronic and chemical properties inherent in the Fe containing cofactor. Fe-S clusters are constructed of inorganic iron and sulfide arranged in a distinct caged structural makeup ranging from [Fe(2) -S(2) ], [Fe(3) -S(4) ], [Fe(4) -S(4) ], up to [Fe(8) -S(8) ] clusters. In eukaryotes, cluster activity is controlled in part at the assembly level and the major pathway for cluster production exists within the mitochondria. Recent insight into the pathway of mitochondrial cluster assembly has come from new in vivo and in vitro reports that provided direct insight into how all protein partners within the assembly pathway interact. However, we are only just beginning to understand the role of each protein within this complex pageant that is mitochondrial Fe-S cluster assembly. In this report we present results, using the yeast model for mitochondrial assembly, to describe the molecular details of how important proteins in the pathway coordinate for cluster assembly.
Lithium Batteries and Cathode Materials

In the previous paper Ralph Brodd and Martin Winter described the different kinds of batteries and fuel cells. In this paper I will describe lithium batteries in more detail, building an overall foundation for the papers that follow which describe specific components in some depth and usually with an emphasis on the materials behavior. The lithium battery industry is undergoing rapid expansion, now representing the largest segment of the portable battery industry and dominating the computer, cell phone, and camera power source industry. However, the present secondary batteries use expensive components, which are not in sufficient supply to allow the industry to grow at the same rate in the next decade. Moreover, the safety of the system is questionable for the large-scale batteries needed for hybrid electric vehicles (HEV). Another battery need is for a high-power system that can be used for power tools, where only the environmentally hazardous Ni/ Cd battery presently meets the requirements. A battery is a transducer that converts chemical energy into electrical energy and vice versa. It contains an anode, a cathode, and an electrolyte. The anode, in the case of a lithium battery, is the source of lithium ions. The cathode is the sink for the lithium ions and is chosen to optimize a number of parameters, discussed below. The electrolyte provides for the separation of ionic transport and electronic transport, and in a perfect battery the lithium ion transport number will be unity in the electrolyte. The cell potential is determined by the difference between the chemical potential of the lithium in the anode and cathode, ∆G ) -EF. As noted above, the lithium ions flow through the electrolyte whereas the electrons generated from the reaction, Li ) Li+ + e-, go through the external circuit to do work. Thus, the electrode system must allow for the flow of both lithium ions and electrons. That is, it must be both a good ionic conductor and an electronic conductor. As discussed below, many electrochemically active materials are not good electronic conductors, so it is necessary to add an electronically conductive material such as carbon * To whom correspondence should be addressed. Phone and fax: (607) 777-4623. E-mail: stanwhit@binghamton.edu. 4271 Chem. Rev. 2004, 104, 4271−4301
Synthesis of Anthracyclinone Precursor: 5,12‐Dihydroxy‐1,3,4‐trihydronaphthacene‐2,6,11‐quinone

Abstract Two practical and efficient approaches for preparing large quantities of 5,12‐dihydroxy‐1,3,4‐trihydronaphthacene‐2,6,11‐quinone 9 are described. Both synthetic approaches involve a simple route with a fewer number of steps and utilize readily available and inexpensive starting materials. Large‐scale production of this precursor may prove to be useful for further research involving the synthesis of antineoplastic anthracyclines and development of their analogs with increased activity and decreased toxicity.
Subsistence Entrepreneurs and Misallocation

Empirical evidence suggests that many individuals in developing countries operate businesses not due to some superior skill or idea, but because they lack the opportunity to become salaried employees. In a model with incomplete markets, occupational choice, and frictional job search, I argue that this is due to the interaction of low unemployment benets and nancial market underdevelopment. The resulting misallocation along the extensive margin between salaried positions and business ownership generates a larger left tail of rm size and a signicantly smaller quantitative impact of targeted lending to poor entrepreneurs. Model predictions are then tested with individual-level surveys of both Chilean and Mexican microenterprise owners. Evidence shows that misallocated owners have lower prot conditional on observable inputs and are more likely to have left their last salaried position involuntarily. Both are consistent with the model.
Encoding the structure of many-body localization with matrix product operators

Anderson insulators are noninteracting disordered systems which have localized single-particle eigenstates. The interacting analog of Anderson insulators are the many-body localized (MBL) phases. The spectrum of the many-body eigenstates of an Anderson insulator is efficiently represented as a set of product states over the single-particle modes. We show that product states over matrix product operators of small bond dimension is the corresponding efficient description of the spectrum of an MBL insulator. In this language all of the many-body eigenstates are encoded by matrix product states (i.e., density matrix renormalization group wave functions) consisting of only two sets of low bond dimension matrices per site: the ${G}_{i}$ matrices corresponding to the local ground state on site $i$ and the ${E}_{i}$ matrices corresponding to the local excited state. All ${2}^{n}$ eigenstates can be generated from all possible combinations of these sets of matrices.
Parameterization for Remeshing Over Dynamically Changing Domains

We present a method for incrementally maintaining a global, bijective mapping between an arbitrary triangular input mesh and a dynamically changing domain mesh by use of a meta-mesh. The domain mesh is derived from the input mesh through an arbitrary sequence of local mesh connectivity operations. The mapping can be maintained independent of the choice of metrics for driving the simplification process to derive the domain mesh. In addition, due to the dynamic nature of the mapping, user post-processing can be applied to adjust the final domains.
The Role of Organizations in Fostering Public Service Motivation

In seeking to explain the antecedents of public service motivation, James Perry focuses on the formative role of sociohistorical context. Th is study tests Perry’s theory and examines the role that organizational factors play in shaping public service motivation, based on responses from a national survey of state government health and human service managers. Th e fi ndings support the role of sociohistorical context, showing that public service motivation is strongly and positively related to level of education and membership in professional organizations. Th e results also underscore the signifi cant infl uence of organizational institutions, indicating that red tape and length of organizational membership are negatively related to public service motivation, whereas hierarchical authority and reform eff orts have a positive relationship. Th erefore, public organizations have both an opportunity and a responsibility to create an environment that allows employees to feel they are contributing to the public good.
Successful Treatment of Severe Aortic Stenosis With Transcatheter Aortic Valve Implantation in a Centenarian Patient

Copyright©2014 Korean Geriatric Society This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/). Successful Treatment of Severe Aortic Stenosis With Transcatheter Aortic Valve Implantation in a Centenarian Patient Yong-Joon Lee, MD, Young-Ju Kim, MD, Jung-Hee Lee, Young-Guk Ko, MD, Sanghoon Shin, MD, Geuru Hong, MD, Sak Lee, MD, Byung-Chul Chang, MD, Jae-Kwang Shim, MD, Young-Ran Kwak, MD, Myeong-Ki Hong, MD Divisions of Cardiology, Thoracic and Cardiovascular Surgery, and Anesthesiology and Pain Medicine, Severance Cardiovascular Hospital, Yonsei University Health System, Seoul, Korea
VLF observation of long ionospheric recovery events

[1] We introduce a new class of Early/fast VLF events with recoveries of up to 20 min, much longer than typical Early/fast and Lightning-induced Electron Precipitation (LEP) events which recover to pre-event levels in ≲200 s. Three distinct types of long recovery events are observed, each exhibiting different characteristics, with the observed features of at least some of the event types consistent with the possibility of persistent ionization at altitudes below 60 km as put forth by Lehtinen and Inan (2007).
Vibrations of jammed disk packings with Hertzian interactions

Contact breaking and Hertzian interactions between grains can both give rise to nonlinear vibrational response of static granular packings. We perform molecular dynamics simulations at constant energy in 2D of frictionless bidisperse disks that interact via Hertzian spring potentials as a function of energy and measure directly the vibrational response from the Fourier transform of the velocity autocorrelation function. We compare the measured vibrational response of static packings near jamming onset to that obtained from the eigenvalues of the dynamical matrix to determine the temperature above which the harmonic approximation breaks down. We compare packings that interact via single-sided (purely repulsive) and double-sided Hertzian spring interactions to disentangle the effects of the shape of the potential from contact breaking. Our studies show that while Hertzian interactions lead to weak nonlinearities in the vibrational behavior (e.g. the generation of harmonics of the eigenfrequencies of the dynamical matrix), the vibrational response of static packings with Hertzian contact interactions is dominated near jamming by contact breaking as found for systems with repulsive linear spring interactions.
ALADIN: algorithms for Learning and Architecture DetermINation

This paper presents the development of learning algorithms which are capable of selecting and training the simplest feed-forward neural network for a given application. This is achieved by deactivating the redundant hidden units during the training of the network on the basis of a criterion relating to the effect of each hidden unit on the training process. The information inherent in the training set is subsequently distributed over the remaining active hidden units. In addition to the algorithms based on the quadratic error criterion frequently used for the training of neural networks, this paper also presents the development of fast algorithms based on a new generalized criterion which accelerates the training of neural networks. The proposed algorithms are experimentally evaluated and tested. >
Probabilistic evaluation of sequential plans from causal models with hidden variables

The paper concerns the probabilistic evaluation of plans in the presence of unmeasured variables, each plan consisting of several concurrent or sequential actions. We establish a graphical criterion for recognizing when the effects of a given plan can be predicted from passive observations on measured variables only. When the criterion is satisfied, a closed-form expression is provided for the probability that the plan will achieve a specified goal.
Lectures on superstring and M theory dualities

These lectures begin by reviewing the evidence for S duality of the toroidally compactified heterotic string in 4d that was obtained in the period 1992–94. Next they review recently discovered dualities that relate all five of the 10d superstring theories and a quantum extension of 11d supergravity called M theory. The study of p -branes of various dimensions (some of which are D -branes) plays a central role. The final sections survey supersymmetric string vacua in 6d and some of the dual constructions by which they can be obtained. Special emphasis is given to a class of N = 1 models that exhibit “heterotic-heterotic duality.”
Nonlinear Regressions with Integrated Time Series

An asymptotic theory is developed for nonlinear regression with integrated processes. The models allow for nonlinear effects from unit root time series and therefore deal with the case of parametric nonlinear cointegration. The theory covers integrable and asymptotically homogeneous functions. Sufficient conditions for weak consistency are given and a limit distribution theory is provided. The rates of convergence depend on the properties of the nonlinear regression function, and are shown to be as slow as n 1/4 for integrable functions, and to be generally polynomial in n 1/2 for homogeneous functions. For regressions with integrable functions, the limiting distribution theory is mixed normal with mixing variates that depend on the sojourn time of the limiting Brownian motion of the integrated process.
Behavior of lacunary series at the natural boundary

Abstract We develop a local theory of lacunary Dirichlet series of the form ∑ k = 1 ∞ c k exp ( − z g ( k ) ) , Re ( z ) > 0 as z approaches the boundary i R , under the assumption g ′ → ∞ and further assumptions on c k . These series occur in many applications in Fourier analysis, infinite order differential operators, number theory and holomorphic dynamics among others. For relatively general series with c k = 1 , the case we primarily focus on, we obtain blow up rates in measure along the imaginary line and asymptotic information at z = 0 . When sufficient analyticity information on g exists, we obtain Borel summable expansions at points on the boundary, giving exact local description. Borel summability of the expansions provides property-preserving extensions beyond the barrier. The singular behavior has remarkable universality and self-similarity features. If g ( k ) = k b , c k = 1 , b = n or b = ( n + 1 ) / n , n ∈ N , behavior near the boundary is roughly of the standard form Re ( z ) − b ′ Q ( x ) where Q ( x ) = 1 / q if x = p / q ∈ Q and zero otherwise. The Botcher map at infinity of polynomial iterations of the form x n + 1 = λ P ( x n ) , | λ | λ 0 ( P ) , turns out to have uniformly convergent Fourier expansions in terms of simple lacunary series. For the quadratic map P ( x ) = x − x 2 , λ 0 = 1 , and the Julia set is the graph of this Fourier expansion in the main cardioid of the Mandelbrot set.
Defect-induced resonant tunneling of electromagnetic waves through a polariton gap

We consider tunneling of electromagnetic waves through a polariton band gap of a 1-D chain of atoms. We analytically demonstrate that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect.
SYNTHESIS OF 2-(TRIMETHYLSILYL)ETHYL α-d-MANNOPYRANOSIDES REVISITED

Glycosylation of 2-(trimethylsilyl)ethanol with various ethyl 1-thioglycosides, which were activated with N-iodosuccinimide and silver triflate, was studied. The starting thioglycosides, some prepared for the first time, were obtained conventionally from the corresponding α-1-acetates. When β-1-acetates were more readily available, these were converted to the α-anomers by anomerization, prior to the glycosylation. Using ethyl 1-thioglycosides as glycosyl donors, especially those bearing a pivaloyl or a nonparticipating group at O-2, the corresponding 2-(trimethylsilyl)ethyl α-d-mannopyranosides were obtained in excellent yields.
Health Effects of Arsenic and Chromium in Drinking Water: Recent Human Findings

Even at high concentrations, arsenic-contaminated water is translucent, tasteless, and odorless. Yet almost every day, studies report a continually increasing plethora of toxic effects that have manifested in exposed populations throughout the world. In this article we focus on recent findings, in particular those associated with major contributions since 2006. Early life exposure, both in utero and in childhood, has been receiving increased attention, and remarkable increases in consequent mortality in young adults have been reported. New studies address the dose-response relationship between drinking-water arsenic concentrations and skin lesions, and new findings have emerged concerning arsenic and cardiovascular disease. We also review the increasing epidemiological evidence that the first step of methylation of inorganic arsenic to monomethylated arsenic (MMA) is actually an activation step rather than the first step in detoxification, as once thought. Hexavalent chromium differs from arsenic in that it discolors water, turning the water yellow at high concentrations. A controversial issue is whether chromium causes cancer when ingested. A recent publication supports the original findings in China of increased cancer mortality in a population where well water turned yellow with chromium.
Cosmic Acceleration and a Natural Solution to the Cosmological Constant Problem

We trace the origin of the cosmological constant problem to the assumption that Newton's constant $G$ sets the scale for cosmology. And then we show that once this assumption is relaxed, the very same cosmic acceleration which has served to make the cosmological constant problem so very severe instead then serves to provide us with its potential resolution. We present an alternate cosmology, one based on conformal gravity, and show that once given only that the sign of the vacuum energy density $\Lambda$ is explicitly the negative one associated with spontaneous breakdown of the scale invariance of the conformal theory (this actually being the choice of sign for $\Lambda$ which precisely leads to cosmic acceleration in conformal gravity), then that alone, no matter how big $\Lambda$ might actually be in magnitude, is sufficient to not only make its measurable contribution to current era cosmology naturally be of order one today, but to even do so in a way which is completely compatible with the recent high $z$ supernovae cosmology data. Cosmology can thus live with either a fundamental $G$ or with the large (and even potentially negative) $\Lambda$ associated with elementary particle physics phase transitions but not with both. Also, we distinguish between the free energy and the internal energy, with it being the former which determines cosmological phase transitions and the latter which is the source of the gravitational field. Then we show that, even if we make the standard ad hoc assumption that $\Lambda$ actually is quenched in standard gravity, vacuum energy is nonetheless still found to dominate standard cosmology at the time of the phase transition which produced it. However, within conformal gravity no such difficulty is encountered.
The Role of the Independent: Ralph B. Lloyd and the Development of California's Coastal Oil Region, 1900-1940

Independents, or nonintegrated companies, played a significant role in finding and producing crude oil in California, just as they had in Texas. They were able to do so because the resources of majors, or integrated firms, were not decisive in the search for oil. As both majors and independents increased in number, the factors of risk and uncertainty persuaded independents and majors to cooperate with each other. The case of Ralph B. Lloyd demonstrates the argument. Lloyd was a forceful individual who used his preeminent leasing position to shape the development of the Ventura Avenue field—the largest in the coastal region—through symbiotic relations with Shell and Associated. Lloyd's role is not captured in the data that scholars often use to demonstrate the dominance of m ajors in the California oil industry.
Synthesis of chiral hydroxyl phospholanes from D-mannitol and their use in asymmetric catalytic reactions.

Chiral hydroxyl monophosphane 3 [(2S,3S,4S,5S)-3,4-dihydroxy-2,5-dimethyl-1-phenylphospholane] and bisphospholanes 5a [1,2-bis[(2S,3S,4S,5S)-3,4-dihydroxy-2,5-dimethylphospholanyl]benzene] and 5b [1,2-bis[(2S,3S,4S,5S)-2,5-diethyl-3,4-dihydroxyphospholanyl]benzene] were synthesized from readily available d-mannitol in high yields. Strategies for protection and deprotection of OH-groups in the presence of phosphines have been explored. Rate acceleration in the Baylis−Hillman reaction was observed when a hydroxyl phosphine was used as the catalyst. Rhodium complexes with chiral bisphospholanes are highly enantioselective catalysts for the asymmetric hydrogenation of various kinds of functionalized olefins such as dehydroamino acid derivatives, itaconic acid derivatives, and enamides. An interesting feature of the hydroxyl phospholane system is that hydrogenation of some substrates can be carried out in water with >99% ee and 100% conversion (e.g., itaconic acid).
On a rate control protocol for networked estimation

We study the problem of congestion control in a communication network that is supporting remote estimation of multiple processes. A stochastic rate control protocol is developed using the network utility maximization (NUM) framework. This decentralized protocol avoids congestion by regulating the transmission probabilities of the sources. The presence of estimation costs poses new challenges; however, for low congestion levels, the form of rate controller resembles that of the standard TCP rate controller. Stability of the protocol is analyzed in the presence of fixed network delays.
The link-prediction problem for social networks

Given a snapshot of a social network, can we infer which new interactions among its members are likely to occur in the near future? We formalize this question as the link-prediction problem, and we develop approaches to link prediction based on measures for analyzing the “proximity” of nodes in a network. Experiments on large coauthorship networks suggest that information about future interactions can be extracted from network topology alone, and that fairly subtle measures for detecting node proximity can outperform more direct measures. © 2007 Wiley Periodicals, Inc.
The Relationship of Worry About Hypoglycemia With Diabetes-specific and Typical Youth Behavior Among Emerging Adults With Type 1 Diabetes

PurposeLittle is known about the relationship of worry about hypoglycemia with diabetes-specific and typical youth behaviors among emerging adults with type 1 diabetes. This study’s purpose was to ...
Anomalies, branes, and currents

Abstract When a D-brane wraps around a cycle of a curved manifold, the twisting of its normal bundle can induce chiral asymmetry in its world-volume theory. We obtain the general form of the resulting anomalies for D-branes and their intersections. They are not cancelled among themselves, and the standard inflow mechanism does not apply at first sight because of their apparent lack of factorizability and the apparent vanishing of the corresponding inflow. We show, however, that after taking into consideration the effects of the non-trivial topology of the normal bundles, the anomalies can be transformed into factorized forms and precisely cancelled by finite inflow from the Chern-Simons actions for the D-branes as long as the latter are well defined. We then consider examples in type 11 compactifications where the twisting of the normal bundles occurs and calculate the changes in the induced Ramond-Ramond charges on the D-branes.
Modeling pedestal experiments with amplitude instead of contrast.

Abstract To provide a comprehensive quantitative model of contrast discrimination, we measured contrast discrimination functions at four mean luminances, four spatial frequencies, three phase relations between tests and pedestal gratings, and two temporal frequencies for the test grating. The results confirm previous findings that the shape of the contrast discrimination function varies with three of these variables but is independent of luminance when each discrimination threshold is divided by the detection threshold for the test grating presented alone. The data in this 5-dimensional space can be described quantitatively if expressed in amplitudes instead of contrasts. The resulting model of visual amplitude sensitivity has seven parameters that are specific to a particular observer and are tied to identifiable visual properties. The “pedestal effect” and tests with the pedestal and test gratings out-of-phase can be explained by subthreshold summation but not stimulus uncertainty.