cssi/SciSciGPT-SciSciNet huggingface dataset:
Analysis of single nanoparticle detection by using 3-dimensionally confined optofluidic ring resonators

Viral particles are responsible for the majority of human fatal diseases, including Ebola fever, influenza, HIV, SARS, dengue fever, and so on. Those small infectious agents with radius ranging from 1 nm to 800 nm spread and transmit extremely rapidly, and leave very limited time for treatment if humans are infected [1]. The prevention and early diagnosis of those diseases require fast and trace amount detection of virus in liquid and in air. Among many approaches employed, the optical ring resonator based biosensor is one of the most sensitive devices, capable of detecting a single virion or nanoparticle in a real-time and label-free manner [2–3]. In a ring resonator, light circulates and forms whispering-gallery modes (WGMs). When a virion or nanoparticle binds onto the resonator surface, its interaction with the WGM leads to a spectral shift or mode splitting [2–3]. To date, by measuring the wavelength shift, a single influenza particle (50 nm in radius) in liquid has been detected experimentally with a solid microsphere [2]. Recently, by measuring the mode splitting, the detection and sizing of a single nanoparticle (30 nm in radius) in air have also been demonstrated with a microtoroid [3]. However, despite their excellent sensing performance, both structures lack of an efficient fluidic system to rapidly deliver samples to the sensing head (i.e., the ring resonator), which may significantly lengthen the detection time, in particular, when detecting a single nanoparticle.
5-Hydroxyl Hydantoins via One-Pot Microwave-Assisted Air Oxidation of Ugi Products

The novel and one-pot synthesis of 5-hydroxyl hydantoins from Ugi five-component condensation procedures is reported. The transformation was promoted via a microwave heating method and provided 5-hydroxyl hydantoins in workable yields, representing a direct approach to this synthetically challenging and biologically interesting pharmacophore.
PRE- AND POST-OPERATIVE OPIOID USE IN TJA: A CLEAR AND PRESENT DANGER

The United States is in the midst of an opioid epidemic, with the World Health Organization reporting that American9s consume 99% of the world9s supply of hydrocodone and 83% of the world9s oxycodone. Additionally, pre-operative opioid use has been associated with worse clinical outcomes and higher rates of complications following total knee arthroplasty (TKA). This is especially important in the TKA population given that approximately 15% of patients are either dissatisfied or very dissatisfied at least one year after their TKA procedure. Given the concerning rise in opioid use the American Academy of Orthopaedic Surgeons (AAOS) has recently released an information statement with practice recommendations for combating this excessive and inappropriate opiate use. However, little is known regarding peri-operative opioid use for TKA patients. Therefore, the purpose of this study was to: 1) identify rates of opioid use prior to primary TKA, 2) evaluate post-operative trends in opioid use throughout the year following TKA and 3) identify risk factors for prolonged opioid use following TKA. Overall, 31% of TKA patients are prescribed opioids within 3-months prior to TKA; this percentage has increased over 9% during the years included in this study. Pre-operative opioid use was most predictive of increased refills of opioids following TKA, however, other intrinsic patient characteristics were also predictive of prolonged opioid use. These characteristics remained predictive after controlling for opioid user status. The increasing rates of opioid prescribing prior to TKA are concerning, especially given literature concluding opioids have minimal effect on pain or function in patients with osteoarthritis and pre-operative opioid use is associated with poor outcomes and more complications following TKA. This data provides an important baseline for opioid use trends following TKA that can be used for future comparison and identifies risk factors for prolonged use that will be helpful to prescribers as the AAOS works to decreased opioid use, misuse and abuse within the United States.
GLENOHUMERAL VERSION ALIGNMENT: GETTING IT RIGHT THE FIRST TIME

Total shoulder arthroplasty has gone through several generations as instruments and implant designs have given surgeons both more options in the alignment of the components and more guidance in the best choices to make. However, while the measurement of alignment has become more sophisticated, the importance of particular aspects of alignment to actual patient comfort and function has been less completely characterised. Overstuffing of the joint and proud humeral heads have been most associated with clinical failure. The efforts to avoid this can be divided into two camps: The anatomic school, who believe an experienced surgeon can divine the correct anatomy that existed before the distortions of arthritis began, and that the surgeon should make free-hand cuts and alignments to restore the normal anatomy The cutting-guide school, who believe that average versions and positions avoid error and that soft-tissue balancing requires occasional deviations from “normal” anatomy.
The Curvilinear Relationship Between Attitude Certainty and Attitudinal Advocacy

Do people advocate more on behalf of their own attitudes and opinions when they feel certain or uncertain? Although considerable past research suggests that people are more likely to advocate when they feel highly certain, there also is evidence for the opposite effect—that people sometimes advocate more when they experience a loss of certainty. The current research seeks to merge these insights. Specifically, we explore the possibility that the relationship between attitude certainty and attitudinal advocacy is curvilinear. Consistent with this hypothesis, we find evidence for a J-shaped curve: Advocacy intentions (and behavior) peak under high certainty, bottom out under moderate certainty, and show an uptick under low (relative to moderate) certainty. We document this relationship and investigate its potential mechanisms in three studies by examining advocacy intentions and the actual advocacy messages participants write when they feel high, moderate, or low certainty.
Congruence subgroups from representations of the three-strand braid group

Abstract Ng and Schauenburg proved that the kernel of a ( 2 + 1 ) -dimensional topological quantum field theory representation of SL ( 2 , Z ) is a congruence subgroup. Motivated by their result, we explore when the kernel of an irreducible representation of the braid group B 3 with finite image enjoys a congruence subgroup property. In particular, we show that in dimensions two and three, when the projective order of the image of the braid generator σ 1 is between 2 and 5 the kernel projects onto a congruence subgroup of PSL ( 2 , Z ) and compute its level. However, we prove that for three dimensional representations, the projective order is not enough to decide the congruence property. For each integer of the form 2 l ≥ 6 with l odd, we construct a pair of non-congruence subgroups associated with three-dimensional representations having finite image and σ 1 mapping to a matrix with projective order 2l. Our technique uses classification results of low dimensional braid group representations, and the Fricke–Wohlfahrt theorem in number theory.
Freight Service Provision for Disaster Relief: A Competitive Network Model with Computations

In this paper, we develop a competitive freight service provision network model for disaster relief. A humanitarian relief organization is interested in determining its most cost-effective deliveries of needed supplies in a crisis setting. Multiple freight service providers are engaged in competition to acquire the business of carrying the supplies in the amounts desired to the destinations. We describe the objective functions faced by the various decision-makers and their underlying constraints, and present the optimality conditions. We then define the freight service provision network equilibrium for disaster relief and formulate it as a variational inequality problem. We provide qualitative results for the equilibrium product shipment pattern in terms of existence and uniqueness. For completeness, we also construct a new cooperative system-optimization model and discuss the price of anarchy relating the two models, along with additional theoretical results. In addition, we propose algorithmic schemes that take advantage of the underlying network structure of the problem. We present a case study on the shipment of personal protective equipment supplies in the context of the Ebola humanitarian healthcare crisis in west Africa. The computational results in this paper yield insights on the equilibrium shipment and price patterns in the freight service provision sector for humanitarian operations in terms of enhanced or reduced competition, as well as increases in demand.
The transfer of bomb radiocarbon and anthropogenic lead to the deep North Atlantic Ocean observed from a deep sea coral

Abstract Deep-ocean, Δ C 14 , Pb concentrations, and Pb isotopes were reconstructed from a deep-sea coral Enallopsammia rostrata from 1410 m depth off of Bermuda. Our high-resolution time series is created from closely spaced radial cross sections, with samples taken from the center of concentric coral growth bands that we show to be the oldest portion of the section. Prebomb radiocarbon ages from the coral demonstrate that the vertical growth rate of the coral is linear, and the age of the coral is estimated to be 560–630 yr old based on the growth rate. Using this age model to reconstruct Δ C 14 in deep seawater, we first detect bomb radiocarbon at the coral growth site around 1980, and show that Δ C 14 increased from − 80 ± 1 ‰ (average 1930–1979) to a plateau at − 39 ± 3 ‰ (1999–2001). Pb/Ca of the coral ranges between 1.1–4.5 nmol/mol during the 16th and 17th centuries, and Pb isotope ratios (206Pb/207Pb = 1.21, 208Pb/207Pb = 2.495) in this period agree with pre-anthropogenic values found in the pelagic sediments of the North Atlantic Ocean basin. Coral Pb/Ca is slightly elevated to 6.2 ± 0.9 nmol / mol between the 1740s and the 1850s and then increases to 25.1 ± 0.2 nmol / mol in the 1990s. The increase in coral Pb/Ca is accompanied by a decrease in coral 206Pb/207Pb and 208Pb/207Pb, indicating that the increase was caused by the infiltration of anthropogenic Pb to the coral growth site. Comparing our data to the surface coral Δ C 14 and Pb records from Bermuda reveals a time scale of tracer transport from the surface ocean to the coral growth site. Some characteristic features, e.g., the bomb-derived Δ C 14 increase, appear in the deep ocean approximately 25 yr later than the surface, but the overall increase of Δ C 14 and Pb in the deep ocean is smaller and slower than the surface, showing the importance of mixing during the transport of these tracers.
Preliminary uranium enrichment analysis results using cadmium zinc telluride detectors

Abstract Lawrence Livermore National Laboratory (LLNL) and EG and G ORTEC have jointly developed a portable ambient-temperature detection system that can be used in a number of application scenarios. The detection system uses a planar cadmium zinc telluride (CZT) detector with custom-designed detector support electronics developed at LLNL and is based on the recently released MicroNOMAD multichannel analyzer (MCA) produced by ORTEC. Spectral analysis is performed using software developed at LLNL that was originally designed for use with high-purity germanium (HPGe) detector systems. In one application, the CZT detection system determines uranium enrichments ranging from less than 3% to over 75% to within accuracies of 20%. The analysis was performed using sample sizes of 200 g or larger and acquisition times of 30 min. We have demonstrated the capabilities of this system by analyzing the spectra gathered by the CZT detection system from uranium sources of several enrichments. These experiments demonstrate that current CZT detectors can, in some cases, approach performance criteria that were previously the exclusive domain of larger HPGe detector systems.
Magnetite nano-islands on silicon-carbide with graphene

X-ray magnetic circular dichroism (XMCD) measurements of iron nano-islands grown on graphene and covered with a Au film for passivation reveal that the oxidation through defects in the Au film spontaneously leads to the formation of magnetite nano-particles (i.e., Fe3O4). The Fe nano-islands (20 and 75 monolayers; MLs) are grown on epitaxial graphene formed by thermally annealing 6H-SiC(0001) and subsequently covered, in the growth chamber, with nominal 20 layers of Au. Our X-ray absorption spectroscopy and XMCD measurements at applied magnetic fields show that the thin film (20 ML) is totally converted to magnetite, whereas the thicker film (75 ML) exhibits properties of magnetite but also those of pure metallic iron. Temperature dependence of the XMCD signal (of both samples) shows a clear transition at TV≈120 K consistent with the Verwey transition of bulk magnetite. These results have implications on the synthesis of magnetite nano-crystals and also on their regular arrangements on functional substrat...
Thermodynamics of Helix-Coil Transitions of Polyalanine in Open Carbon Nanotubes.

Understanding structure formation in polypeptide chains and synthetic polymers encapsulated in pores is important in biology and nanotechnology. We present replica exchange molecular dynamics studies of the phase diagram for α-helix formation of capped polyalanine in nanotubes (NT) open to a water reservoir as a function of the NT diameter and hydrophobicity. A helix forms only in a narrow range of diameters, which surprisingly is comparable to the width of the ribosome tunnel. Increasing the hydrophobicity enhances helicity in the NT. Helix formation in polyalanine is driven by a small negative enthalpy and a positive entropy change at ≈300 K, in contrast to the large negative entropy change that destabilizes the helix and favors the coiled state in bulk water. There is an anticorrelation between water density inside the nanotube and structure formation. Confinement-induced helix formation depends on amino acid sequence. There is complete absence of helix in polyglutamine and polyserine confined to a ope...
Computing multidimensional persistence

The theory of multidimensional persistence captures the topology of a multifiltration - a multiparameter family of increasing spaces. Multifiltrations arise naturally in the topological analysis of scientific data. In this paper, we give a polynomial time algorithm for computing multidimensional persistence. We recast this computation as a problem within computational commutative algebra and utilize algorithms from this area to solve it. While the resulting problem is EXPSPACE-complete and the standard algorithms take doubly-exponential time, we exploit the structure inherent withing multifiltrations to yield practical algorithms. We implement all algorithms in the paper and provide statistical experiments to demonstrate their feasibility.
Adverse Selection and Auction Design for Internet Display Advertising

Abstract We model an online display advertising environment in which “performance” advertisers can measure the value of individual impressions, whereas “brand” advertisers cannot. If advertiser values for ad opportunities are positively correlated, second-price auctions for impressions can be inefficient and expose brand advertisers to adverse selection. Bayesian-optimal auctions have other drawbacks: they are complex, introduce incentives for false-name bidding, and do not resolve adverse selection. We introduce “modified second bid” auctions as the unique auctions that overcome these disadvantages. When advertiser match values are drawn independently from heavy-tailed distributions, a modified second bid auction captures at least 94.8 percent of the first-best expected value. In that setting and similar ones, the benefits of switching from an ordinary second-price auction to the modified second bid auction may be large, and the cost of defending against shill bidding and adverse selection may be low. (J...
Relations between executive function, behavioral regulation, and achievement: Moderation by family income.

Abstract Children's executive function (EF) and behavioral regulation skills are robust predictors of academic success. The current study examines differential associations between measures of EF, classroom behavioral regulation, and academic achievement by children's family income in a sample of 100 prekindergarten children. In correlational analyses, EF and classroom behavioral regulation were more strongly associated for children not in low-income families, although only one comparison between correlations reached statistical significance. In regression models controlling for age, gender, and maternal education, EF and classroom behavioral regulation were generally similarly related to achievement regardless of family income. However, inhibitory control was significantly less associated with mathematics and vocabulary for children in low-income families than for children not. These findings suggest similarities in associations between EF, behavioral regulation, and academic achievement regardless of family income, with evidence of only a few exceptions. Potential implications for early childhood interventions in low-income populations are considered.
Managing Resource Limitation of Best-Effort HTM

The first release of hardware transactional memory (HTM) as commodity processor posed the question of how to efficiently handle its best-effort nature. In this paper we present Part-HTM, a hybrid transactional memory protocol that solves the problem of transactions aborted due to the resource limitations (space/time) of current best-effort HTM. The basic idea of Part-HTM is to partition those transactions into multiple sub-transactions, which can likely be committed in hardware. Due to the eager nature of HTM, we designed a low-overhead software framework to preserve transaction’s correctness (with and without opacity) and isolation. Part-HTM is effective: our evaluation study confirms that its performance is the best in all tested cases, except for those where HTM cannot be outperformed. However, in such a workload, Part-HTM still performs better than all other software and hybrid competitors.
Social network integration and user content generation: evidence from natural experiments

This study examines how social network integration (i.e., integration of online platforms with other social media services, for example, with Facebook or Twitter) can affect the characteristics of user-generated content (volume and linguistic features) in the context of online reviews. Building on the social presence theory, we propose a number of hypotheses on how social network integration affects review volume and linguistic features of review text. We consider two natural experiments at leading online review platforms (Yelp.com and TripAdvisor.com), wherein each implemented a social network integration with Facebook. Constructing a unique panel dataset of online reviews for a matched set of restaurants across the two review sites, we estimate a difference-in-differences (DID) model to assess the impact of social network integration. We find that integration with Facebook increased the production of user-generated content and positive emotion in review text, while simultaneously decreasing cognitive language, negative emotion, and expressions of disagreement (negations) in review text. Our findings demonstrate that social network integration works as a double-edged sword. On the one hand, integration provides benefits in terms of increased review quantity. On the other hand, these benefits appear to come at the cost of reduced review quality, given past research which has found that positive, emotional reviews are perceived by users to be less helpful. We discuss the implications of these results as they relate to the creation of sustainable online social platforms for user content generation.
Quantum Dynamics and Spectroscopy of Ab Initio Liquid Water: The Interplay of Nuclear and Electronic Quantum Effects.

Understanding the reactivity and spectroscopy of aqueous solutions at the atomistic level is crucial for the elucidation and design of chemical processes. However, the simulation of these systems requires addressing the formidable challenges of treating the quantum nature of both the electrons and nuclei. Exploiting our recently developed methods that provide acceleration by up to 2 orders of magnitude, we combine path integral simulations with on-the-fly evaluation of the electronic structure at the hybrid density functional theory level to capture the interplay between nuclear quantum effects and the electronic surface. Here we show that this combination provides accurate structure and dynamics, including the full infrared and Raman spectra of liquid water. This allows us to demonstrate and explain the failings of lower-level density functionals for dynamics and vibrational spectroscopy when the nuclei are treated quantum mechanically. These insights thus provide a foundation for the reliable investigat...
Weak approximation for general degree two del Pezzo surfaces

We address weak approximation for certain del Pezzo surfaces defined over the function field of a curve. We study the rational connectivity of the smooth locus of degree two del Pezzo surfaces with two A1 singularities in order to prove weak approximation for degree two del Pezzo surfaces with square-free discriminant.
Toral algebraic sets and function theory on polydisks

A toral algebraic set A is an algebraic set in ℂnwhose intersection with Tnis sufficiently large to determine the holomorphic functions on A. We develop the theory of these sets, and give a number of applications to function theory in several variables and operator theoretic model theory. In particular, we show that the uniqueness set for an extremal Pick problem on the bidisk is a toral algebraic set, that rational inner functions have zero sets whose irreducible components are not toral, and that the model theory for a commuting pair of contractions with finite defect lives naturally on a toral algebraic set.
The Elaboration Likelihood Model: A Meta-Theory for Synthesizing Auditor Judgment and Decision-Making Research

SUMMARY Critics argue that audit research rarely impacts practice, in part due to challenges associated with synthesizing and interpreting research. We propose that using the Elaboration Likelihood...
The Economist as Plumber

Abstract As economists increasingly help governments design new policies and regulations, they take on an added responsibility to engage with the details of policy making and, in doing so, to adopt the mindset of a plumber. Plumbers try to predict as well as possible what may work in the real world, mindful that tinkering and adjusting will be necessary since our models gives us very little theoretical guidance on what (and how) details will matter. This essay argues that economists should seriously engage with plumbing, in the interest of both society and our discipline.
TURN TAP: Temporal Unit Regression Network for Temporal Action Proposals

Temporal Action Proposal (TAP) generation is an important problem, as fast and accurate extraction of semantically important (e.g. human actions) segments from untrimmed videos is an important step for large-scale video analysis. We propose a novel Temporal Unit Regression Network (TURN) model. There are two salient aspects of TURN: (1) TURN jointly predicts action proposals and refines the temporal boundaries by temporal coordinate regression: (2) Fast computation is enabled by unit feature reuse: a long untrimmed video is decomposed into video units, which are reused as basic building blocks of temporal proposals. TURN outperforms the previous state-of-the-art methods under average recall (AR) by a large margin on THUMOS-14 and ActivityNet datasets, and runs at over 880 frames per second (FPS) on a TITAN X GPU. We further apply TURN as a proposal generation stage for existing temporal action localization pipelines, it outperforms state-of-the-art performance on THUMOS-14 and ActivityNet.
Transitive inference in humans (Homo sapiens) and rhesus macaques (Macaca mulatta) after massed training of the last two list items.

Transitive inference (TI) is a classic learning paradigm for which the relative contributions of experienced rewards and representation-based inference have been debated vigorously, particularly regarding the notion that animals are capable of logic and reasoning. Rhesus macaque subjects and human participants performed a TI task in which, prior to learning a 7-item list (ABCDEFG), a block of trials presented exclusively the pair FG. Contrary to the expectation of associative models, the high prior rate of reward for F did not disrupt subsequent learning of the entire list. Monkeys (who each completed many sessions with novel stimuli) learned to anticipate that novel stimuli should be preferred over F. We interpret this as evidence of a task representation of TI that generalizes beyond learning about specific stimuli. Humans (who were task-naive) showed a transitory bias to F when it was paired with novel stimuli, but very rapidly unlearned that bias. Performance with respect to the remaining stimuli was consistent with past reports of TI in both species. These results are difficult to reconcile with any account that assigns the strength of association between individual stimuli and rewards. Instead, they support sophisticated cognitive processes in both species, albeit with some species differences. (PsycINFO Database Record
Numerical methods for the inverse problem of density functional theory

The inverse problem of Kohn–Sham density functional theory (DFT) is often solved in an effort to benchmark and design approximate exchange-correlation potentials. The forward and inverse problems of DFT rely on the same equations but the numerical methods for solving each problem are substantially different. We examine both problems in this tutorial with a special emphasis on the algorithms and error analysis needed for solving the inverse problem. Two inversion methods based on partial differential equation constrained optimization and constrained variational ideas are introduced. We compare and contrast several different inversion methods applied to one-dimensional finite and periodic model systems.
Analyzing evolving stories in news articles

There is an overwhelming number of news articles published every day around the globe. Following the evolution of a news story is a difficult task given that there is no such mechanism available to track back in time to discover and study the hidden relationships between relevant events in digital news feeds. The techniques developed so far to extract meaningful information from a massive corpus rely on similarity search, which results in a myopic loopback to the same topic without providing the needed insights to hypothesize the origin of a story that may be completely different than the news today. In this paper, we present an algorithm that mines historical news data to detect the origin of an event, segments the timeline into disjoint groups of coherent news articles, and outlines the most important documents in a timeline with a soft probability to provide a better understanding of the evolution of a story. Qualitative and quantitative evaluations of our framework demonstrate that our algorithm discovers statistically significant and meaningful stories in reasonable time. Additionally, a relevant case study on a set of news articles demonstrates that the generated output of the algorithm holds the promise to aid prediction of future entities (e.g., actors) in a story.
Reasoning About Safety-Critical Information Flow Between Pilot and Computer

This paper presents research results that develop a dynamic logic for reasoning about safety-critical information flow among humans and computers. The logic advances previous efforts to develop logics of agent knowledge, which make assumptions that are too strong for realistic human agents. We introduce Dynamic Agent Safety Logic (DASL), based on Dynamic Epistemic Logic (DEL), with extensions to account for safe actions, belief, and the logical relationships among knowledge, belief, and safe action. With this logic we can infer which safety-critical information a pilot is missing when executing an unsafe action. We apply the logic to the Air France 447 incident as a case study and provide a mechanization of the case study in the Coq proof assistant.
Step-polarization impedance spectroscopy of implant alloys in physiologic solutions

A novel test method is presented whereby the polarization behavior and impedance characteristics of an electrochemical interface can be determined simultaneously from potential-step current transient responses. In this test, small incremental steps in potential are applied to an electrochemical interface and the current transient response is collected digitally. Then, the data are subjected to a numerical Laplace transform technique to obtain the frequency-dependent admittance (reciprocal impedance) of the interface. From this analysis, several interesting and relevant parameters, including the high- and low-frequency resistances, interfacial capacitance, and polarization behavior, can be obtained. The mathematical basis for this technique is presented and the methodology is applied to three implant alloys (titanium, Co-Cr-Mo, and platinum). Electrochemical tests were performed in 0.9% NaCl at room temperature. Starting at an initial negative potential, the samples were stepped in 50-mV increments every 10 or 100 s up to a maximum potential and then reversed back to the starting potential. The impedances were calculated and used to evaluate the behavior. From these tests, one can determine the potential dependence of the oxide film thickness as well as the changes in the underlying electrochemical state of the interfaces with potential. This technique is inexpensive and easily applied to any electrochemical system, and yields significantly more electrochemical information than either anodic polarization or electrochemical impedance spectroscopy alone. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 40, 233–243, 1998.
Robust time series estimation

In this paper we present some new results on the problem of robust estimation for stationary multiple time series processes. For these processes, we consider the prediction, smoothing and causal filtering problem in cases for which the minimum achievable mean square error is expressed in a closed form in terms of the spectral density matrix of the signal. We consider three convex classes of spectral uncertainties, and develop robust solutions for these cases.
The Role of Natural Climate Variability in Recent Tropical Expansion

AbstractObservations show the tropical belt has widened over the past few decades, a phenomenon associated with poleward migration of subtropical dry zones and large-scale atmospheric circulation. Coupled climate models also simulate tropical belt widening, but less so than observed. Reasons for this discrepancy, and the mechanisms driving the expansion remain uncertain. Here, the role of unforced, natural climate variability—particularly natural sea surface temperature (SST) variability—in recent tropical widening is shown. Compared to coupled ocean–atmosphere models, atmosphere-only simulations driven by observed SSTs consistently lead to larger rates of tropical widening, especially in the Northern Hemisphere (NH), highlighting the importance of recent SST evolution. Assuming the ensemble mean SSTs from historical simulations accurately represent the externally forced response, the observed SSTs can be decomposed into a forced and an unforced component. Targeted simulations with the Community Atmospher...
Life on Mars

Although the Viking results may indicate that Mars has no life today, the possibility exists that Mars may hold the best record of the events that led to the origin of life. There is direct geomorphological evidence that in the past Mars had large amounts of liquid water on its surface. Atmospheric models would suggest that this early period of hydrological activity was due to the presence of a thick atmosphere and the resulting warmer temperatures. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. If Mars did maintain a clement environment for longer than it took for life to originate on Earth, then the question of the origin of life on Mars follows naturally.
Crystalline Ordering and Large Fugacity Expansion for Hard-Core Lattice Particles

Using an extension of Pirogov–Sinai theory, we prove phase transitions, corresponding to sublattice orderings, for a general class of hard-core lattice particle systems with a finite number of perfect coverings. These include many cases for which such transitions have been proven. The proof also shows that for these systems the Gaunt–Fisher expansion of the pressure in powers of the inverse fugacity (aside from an explicit logarithmic term) has a nonzero radius of convergence.
Bayesian Inference in Spatial Sample Selection Models

In this study, we consider Bayesian methods for the estimation of a sample selection model with spatially correlated disturbance terms. We design a set of Markov chain Monte Carlo algorithms based on the method of data augmentation. The natural parameterization for the covariance structure of our model involves an unidentified parameter that complicates posterior analysis. The unidentified parameter – the variance of the disturbance term in the selection equation – is handled in different ways in these algorithms to achieve identification for other parameters. The Bayesian estimator based on these algorithms can account for the selection bias and the full covariance structure implied by the spatial correlation. We illustrate the implementation of these algorithms through a simulation study and an empirical application.
Unsupervised Sequence Classification using Sequential Output Statistics

We consider learning a sequence classifier without labeled data by using sequential output statistics. The problem is highly valuable since obtaining labels in training data is often costly, while the sequential output statistics (e.g., language models) could be obtained independently of input data and thus with low or no cost. To address the problem, we propose an unsupervised learning cost function and study its properties. We show that, compared to earlier works, it is less inclined to be stuck in trivial solutions and avoids the need for a strong generative model. Although it is harder to optimize in its functional form, a stochastic primal-dual gradient method is developed to effectively solve the problem. Experiment results on real-world datasets demonstrate that the new unsupervised learning method gives drastically lower errors than other baseline methods. Specifically, it reaches test errors about twice of those obtained by fully supervised learning.
The Asymptotically Self-Similar Regime for the Einstein Vacuum Equations

We develop a local theory for the construction of singular spacetimes in all spacetime dimensions which become asymptotically self-similar as the singularity is approached. The techniques developed also allow us to construct and classify exact self-similar solutions which correspond to the formal asymptotic expansions of Fefferman–Graham’s ambient metric.
Aging With a Physical Disability in Medicaid Managed Care

This study examines health services appraisal (HSA) and unmet health-care needs for adults (age 50 and over) with physical disabilities in Medicaid managed care (MMC) versus Medicaid fee for service (FFS). Surveys from 309 individuals in MMC and 349 in FFS 2 years after MMC implementation included demographics, MMC processes, HSA, and unmet health-care needs. Regression analyses with HSA and unmet health-care needs as outcomes included demographics and group status (MMC or FFS) for the entire sample, and demographics and MMC processes (continuity of care, experience with care coordinators and primary care physicians) as independent variables for only MMC enrollees. Group status was not associated with HSA or unmet needs. Among MMC enrollees, better health and more positive MMC processes related to higher HSA and lower unmet needs. It is important to consider the perspectives of people aging with disabilities in MMC to better serve their needs.
Should Emerging Markets Worry about U.S. Monetary Policy Announcements

This paper analyzes the spillover effects of U.S. monetary policy announcements on emerging market economies since end-2008, the period coinciding with the use of unconventional policy measures. Monetary policy surprises are measured by changes in two-year Treasury yields in short windows of time around the Federal Reserve Board’s policy announcements. The analysis finds that U.S. monetary policy surprises have a significant impact on emerging economies' exchange rates, equity prices, and bond yields. The impact is larger for surprise tightening of policy than for surprise easing. The impact is disproportionately larger for large surprises, implying that emerging markets are relatively insulated from anticipated policy announcements. The spillover effects of policy announcements of other advanced economies, such as the euro area, Japan, and United Kingdom, are found to be much weaker than those of the United States.
AN EXPERT SYSTEM ARCHITECTURE FOR COPING WITH COMPLEXITY IN COMPUTER-AIDED CONTROL ENGINEERING

Abstract We discuss an architecture for an expert system to assist a control engineer in coping with the complexity of computer-aided control engineering, with major emphasis placed on implementation. Issues to be treated include: rule base organization, knowledge to be contained in various rule bases, a mechanism to switch between rule bases as the problem solution proceeds, a protocol to coordinate the symbolic computations of the inference engine with the numeric computations of conventional analysis and design software, support of non-monotonic reasoning to permit retracting and revising steps in the design process, and conversion between numeric and symbolic data. We present our approach to these issues, and give examples of rules used to represent operational knowledge and to guide the solution of the problem.
Computer Aided Analysis Software for Discrete-event Dynamic System

Abstract A discrete-event system is a system whose behaviour can be discribed by a set of time-consuming activities, performed according to a prescribed ordering. The events concerned correspond to starting or ending time of some activities. This kind of system is not linear in the conventional arithmetic, but is, however, linear in max-algebra. A new kind of linear system, also called psuedo-linear discrete-event system, has been set up. Referring to usual linear system theory, a series of results for modelling and analysis of discrete-event dynamic system (DEDS) are developed, such as state equation, stability, characteristic equation, eigenvalue, periodicity, controllability, observability, etc. The Psuedo-linear Discrete-event System Analysis Package (PDSAP) is to implement the matrix calculations in max-algebra sense, model DEDS and analize performances of the system. Some fundamental contents of max-algebra and DEDS, functions and some algorithms of PDSAP are presented in this paper.
Nuclear Roundness Factor: A Quantitative Approach to Grading in Prostatic Carcinoma, Reliability of Needle Biopsy Tissue, and the Effect of Tumor Stage on Usefulness

Morphometric analysis and histologic grading were performed on case material from 26 patients. Relative nuclear roundness factor (RNRF) was calculated and correlated with clinical course in 14 patients undergoing prostatectomy for stage A or B prostatic carcinoma. The only patients with progression of disease were two with RNRF of 1.10. RNRF in cases without progression ranged from 0.98 to 1.07. Histologic grading by the methods of Gleason or the M.D. Anderson system failed to discriminate between the progressing and nonpro-gressing groups. However, when RNRF was measured in tumors initially diagnosed as stage C or D, four of eight were below 1.10, within the range of the nonprogressing low-stage cases. Thus, the usefulness of morphometry and RNRF may be limited to low-stage disease. It was additionally found that RNRF could not be reliably measured in needle biopsy specimens.
Characterization of the Preformed Antibodies Involved in the Xenograft Reaction

The dog-to-sheep renal xenograft model was utilized to isolate the antibodies that participate in xenograft hyperacute rejection. These sheep antibodies, which were isolated from the rejected dog kidney, agglutinated and killed only dog blood and kidney cells whereas the whole sheep serum reacted with both dog and rabbit cells. The purified antibody was also utilized to obtain in pure form the antigens involved in the hyperacute rejection. When this antigen was tested for its ability to bind the serum of various species, this particular antigen was highly specific for sheep serum and would not react with rabbit, horse, calf, or mouse sera.
A Combination of Active and Passive Video Steganalysis to Fight Sensitive Data Exfiltration through Online Video.

Video Steganalysis is the forensic study of dealing with steganography within a video after a video has been modified by a steganographer. Stego-videos have been used by hackers to exfiltrate data silently out of corporate networks through services such as YouTube and Vimeo. Legal consequences of exfiltration can lead to loss of data confidentiality from within a network and millions of dollars lost in damages. Within the massive frames of a video, passive steganalysis, or statistical detection of video modifications, can be timely, difficult, or costly, because a hacker may reduce the amount of information hidden within a video to fool the steganalyst, or she or he may hide the information in incomplete video regions. In the past, researchers have focused on passive steganalysis, but recently researchers have used an active approach to disarm the modifications done to the video, and this is computationally easier than the passive warden. We demonstrate a novel active steganalysis algorithm, and with it we devise a practical framework using both the active and existing passive approach to prevent and detect possible data exfiltration in video. We find our complete approach improves on existing steganalysis schemes for online video.
Staircase Codes for Secret Sharing With Optimal Communication and Read Overheads

We study the communication efficient secret sharing (CESS) problem. A classical threshold secret sharing scheme encodes a secret into $n$ shares given to $n$ parties, such that any set of at least $t$ , $t , parties can reconstruct the secret, and any set of at most $z$ , $z , colluding parties cannot obtain any information about the secret. A CESS scheme satisfies the previous properties of threshold secret sharing. Moreover, it allows to reconstruct the secret from any set of $d\geq t$ , parties by reading and communicating the minimum amount of information. In this paper, we introduce three explicit constructions of CESS codes called Staircase codes . The first construction achieves optimal communication and read costs for a given $d$ . The second construction achieves optimal costs universally for all possible values of $d$ between $t$ and $n$ . The third construction, which is the most general, achieves optimal costs universally for all values of $d$ in any given set $\Delta \subseteq \{t, {\dots },n\}$ . The introduced Staircase codes can store a secret of maximal size, i.e., equal to $t-z$ shares, and they are all designed over a small finite field $GF(q)$ , for any prime power $q> n$ . However, Staircase codes may require dividing the secret and the shares into many symbols. We also describe how Staircase codes can be used to construct threshold changeable secret sharing with minimum storage cost, i.e., minimum share size.
Armoring Against Coastal Climate Adaptation in the US: A Massachusetts Perspective

ABSTRACTMassachusetts, like many coastal states in the US, stands to be impacted from climate-induced sea level rise. As a result, climate-sensitive coastal policy instruments are critical for providing adequate adaptation options, including an option to allow coastal features to migrate inland. But the migration of coastal features is under threat due to extensive private armoring. This essay highlights specific regulatory instruments at the federal and state level dealing with hard armoring using Massachusetts as an example. It argues specific federal and state regulations legitimize and incentivize hard armoring over other coastal land use planning methods. The current level of armoring in Massachusetts is highlighted and implications under current federal and state policy frameworks are explained. Suggestions for coastal states planning for sea level rise are discussed, including the need for state planning to take the lead. Recommendations for changes at the federal level are also highlighted.
Flow Cytometric Analysis of R3327 Rat Prostate Adenocarcinoma Grown in Vivo and in Vitro

The Dunning R3327 transplantable prostate adenocarcinoma in the Copenhagen rat is an acceptable model for the human disease. The G-subline (a rapidly growing carcinoma) and the H-subline (a slow-growing, well-differentiated adenocarcinoma) represent the extremes of differentiation and growth rate of this tumor. Both sublines were found to have one population that was diploid and a second aneuploid population that was hyperdiploid in DNA content. The percentage of hyperdiploid cells was significantly higher in R3327-G tumors than in R3327-H tumors. The tumor cell population ratios were stable in vivo, but the in vitro culture conditions supported only cells with diploid DNA content following four to five subcultures. These predominantly diploid cultured cells, when injected into intact male rats, resulted in tumors that had both diploid and aneuploid cells.
Numerical simulation of polynomial-speed convergence phenomenon

We provide a hybrid method that captures the polynomial speed of convergence and polynomial speed of mixing for Markov processes. The hybrid method that we introduce is based on the coupling technique and renewal theory. We propose to replace some estimates in classical results about the ergodicity of Markov processes by numerical simulations when the corresponding analytical proof is difficult. After that, all remaining conclusions can be derived from rigorous analysis. Then we apply our results to seek numerical justification for the ergodicity of two 1D microscopic heat conduction models. The mixing rate of these two models are expected to be polynomial but very difficult to prove. In both examples, our numerical results match the expected polynomial mixing rate well.