cssi/SciSciGPT-SciSciNet huggingface dataset:
Identifying high level features of texture perception

Abstract A fundamental issue in texture analysis is that of deciding what textural features are important in texture perception, and how they are used. Experiments on human preattentive vision have identified several low-level features (such as orientation of blobs and size of line segments), which are used in texture perception. However, the question of what higher level features of texture are used has not been adequately addressed. We designed an experiment to help identify the relevant higher order features of texture perceived by humans. We used 20 subjects, who were asked to perform an unsupervised classification of 30 pictures from Brodatz′s album on texture. Each subject was asked to group these pictures into as many classes as desired. Both hierarchical cluster analysis and nonparametric multidimensional scaling (MDS) were applied to the pooled similarity matrix generated from the subjects′ groupings. A surprising outcome is that the MDS solutions fit the data very well. The stress in the two-dimensional case is 0.10, and the stress in the three-dimensional case is 0.045. We rendered the original textures in these coordinate systems, and interpreted the (rotated) axes. It appears that the axes in the 2D case correspond to periodicity versus irregularity, and directionality versus nondirectionality. In the 3D case, the third dimension represents the structural complexity of the texture. Furthermore, the clusters identified by the hierarchical cluster analysis remain virtually intact in the MDS solution. The results of our experiment indicate that people use three high-level features for texture perception. Future studies are needed to determine the appropriateness of these high-level features for computational texture analysis and classification.
Measuring Edge Importance: A Quantitative Analysis of the Stochastic Shielding Approximation for Random Processes on Graphs

Mathematical models of cellular physiological mechanisms often involve random walks on graphs representing transitions within networks of functional states. Schmandt and Galan recently introduced a novel stochastic shielding approximation as a fast, accurate method for generating approximate sample paths from a finite state Markov process in which only a subset of states are observable. For example, in ion-channel models, such as the Hodgkin–Huxley or other conductance-based neural models, a nerve cell has a population of ion channels whose states comprise the nodes of a graph, only some of which allow a transmembrane current to pass. The stochastic shielding approximation consists of neglecting fluctuations in the dynamics associated with edges in the graph not directly affecting the observable states. We consider the problem of finding the optimal complexity reducing mapping from a stochastic process on a graph to an approximate process on a smaller sample space, as determined by the choice of a particular linear measurement functional on the graph. The partitioning of ion-channel states into conducting versus nonconducting states provides a case in point. In addition to establishing that Schmandt and Galan’s approximation is in fact optimal in a specific sense, we use recent results from random matrix theory to provide heuristic error estimates for the accuracy of the stochastic shielding approximation for an ensemble of random graphs. Moreover, we provide a novel quantitative measure of the contribution of individual transitions within the reaction graph to the accuracy of the approximate process.
The Complex Structure of the Cl 1604 Supercluster at z ~ 0.9

The Cl 1604 supercluster at z = 0.9 is one of a small handful of such structures discovered in the high-redshift universe and is the first target observed as part of the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. To date, Cl 1604 is the largest structure mapped at z ~ 1, with the most constituent clusters and the largest number of spectroscopically confirmed member galaxies. In this paper we present the results of a spectroscopic campaign to create a three-dimensional map of Cl 1604 and to understand the contamination by foreground and background large-scale structures. Combining new Deep Imaging Multi-Object Spectrograph observations with previous data yields high-quality redshifts for 1138 extragalactic objects in a ~0.08 deg^2 region, 413 of which are supercluster members. We examine the complex three-dimensional structure of Cl 1604, providing velocity dispersions for eight of the member clusters and groups. Our extensive spectroscopic data set is used to examine potential biases in cluster velocity dispersion measurements in the presence of overlapping structures and filaments. We also discuss other structures found along the line of sight, including a filament at z = 0.6 and two serendipitously discovered groups at z ~ 1.2.
Light-Element Abundances from z = 0 to z = 5

Plausible ratios of deuterium to hydrogen D/H as a function of metallicity, time, and redshift are investigated. Guided by the heavy-element abundance patterns observed locally in Galactic dwarf stars and at large redshift in quasi-stellar object (QSO) absorption-line systems, empirical evolution of the relative abundance ratios Li/D, B/D, N/D, O/D, and F/D for QSO absorption line systems are given for the possible evolutionary patterns in D/H. Limits imposed from the few observations of deuterium and hydrogen in QSO absorption-line systems (QSOALSs) at z ~ 3 are consistent with the expected amount of oxygen produced in stars for the amount of deuterium burned in stars. The atomic properties suggest that the O/D and N/D ratios will be free of substantial ionization, continuum placement, or optical depth errors. The unique advantages of using the O/D and N/D ratio, instead of the D/H ratio, in determining the primordial abundance and subsequent evolution of deuterium is as an important and recurring concept of this paper. Transitions of O I and N I that may be useful in determining precise O/D and N/D ratios in QSOALSs, along with some QSOALS spectra of systems that may be of use in subsequent follow-up searches, are given in the appendices. Definitive detection of lithium, boron, and fluorine in QSOALSs at an appropriate redshift may be able to assist in identifying their chief nucleosynthetic origin sites(s), although the practicality of making positive detections is much lower than for O/D and N/D. Positive detection of any fluorine at a sufficiently large redshift (z 1.5) would suggest strongly a positive detection of the neutrino process operating in massive stars. Observation of these light elements at several redshifts could also provide a useful diagnostic on the conditions of the early universe.
Scalar fields and three-point functions in D = 3 higher spin gravity

We compute boundary three-point functions involving two scalars and a gauge field of arbitrary spin in the AdS vacuum of Vasiliev’s higher spin gravity, for any deformation parameter λ. In the process, we develop tools for extracting scalar field equations in arbitrary higher spin backgrounds. We work in the context of hs[λ] ⊕ hs[λ] Chern-Simons theory coupled to scalar fields, and make efficient use of the associative lone-star product underlying the hs[λ] algebra. Our results for the correlators precisely match expectations from CFT; in particular they match those of any CFT with W ∞[λ] symmetry at large central charge, and with primary operators dual to the scalar fields. As this is expected to include the ‘t Hooft limit of the W N minimal model CFT, our results serve as further evidence of the conjectured AdS/CFT duality between these two theories.
An axiomatic approach to the non-linear theory of generalized functions and consistency of Laplace transforms

We offer an axiomatic definition of a differential algebra of generalized functions over an algebraically closed non-Archimedean field. This algebra is of Colombeau type in the sense that it contains a copy of the space of Schwartz distributions. We study the uniqueness of the objects we define and the consistency of our axioms. Next, we identify an inconsistency in the conventional Laplace transform theory. As an application, we offer a free of contradictions alternative in the framework of our algebra of generalized functions. The article is aimed at mathematicians, physicists and engineers who are interested in the non-linear theory of generalized functions, but who are not necessarily familiar with the original Colombeau theory. We assume, however, some basic familiarity with the Schwartz theory of distributions.
Macrocyclization by Nickel-Catalyzed, Ester-Promoted, Epoxide–Alkyne Reductive Coupling: Total Synthesis of (−)-Gloeosporone†

Ringing the changes: The total synthesis of the title compound centers around a novel strategy that employs a nickel(0)-phosphine complex and triethyl borane in an efficient closure of a 14-membered ring through C--C bond formation (see scheme; cod=cyclooctadiene). The synthesis was accomplished in 10 steps and in approximately 9 % overall yield.
The Pitfalls of International Integration: A Comment on the Bush Proposal and its Aftermath

In January 2003, the Bush Administration proposed a new system for taxing corporate dividends, under which domestic shareholders in U.S. corporations would not be taxed on dividends they received, provided the corporation distributed these dividends out of after-tax earnings (the “Bush Proposal”). The Bush Proposal was introduced in Congress on February 27, 2003. Ultimately, however, Congress balked at enacting full-fledged dividend exemption. Instead, in the Jobs and Growth Tax Relief Reconciliation Act of 2003 (“JGTRRA”) as enacted on May 28, 2003, a lower rate of 15% was adopted for dividends paid by domestic and certain foreign corporations,1 and the capital gains rate was likewise reduced to 15%. Significantly and in stark contrast to the original Bush proposal, under JGTRRA the lower rate for dividends and capital gains does not depend on any tax being paid at the corporate level. This comment will focus primarily on the international aspects of both the Bush Proposal and JGTRRA. I will not lay out the proposal or the law in any detail. Instead, I will ask whether either the Bush Proposal or JGTRRA make sense from an economic efficiency perspective when the international implications are taken into account. I will leave to others the question of whether either the Bush Proposal or JGTRRA are sensible ways to stimulate the economy (for discussion of the effect of the 2001 tax cuts see Shapiro and Slemrod, 2001, 2002). I will also omit any discussion of the distributive effects of either the Bush Proposal or JGTRRA, which have been extensively discussed elsewhere (e.g., Tax Policy Center, 2003; Burman, Gale and Orszag, 2003).
Night eating syndrome and binge eating disorder among persons seeking bariatric surgery: prevalence and related features

Abstract Objective To assess the prevalence of night eating syndrome (NES) and binge eating disorder (BED) and their related behavioral and psychological correlates in persons who sought bariatric surgery. Research Methods and Procedures A consecutive series of 215 persons with extreme obesity (82% women, 70% European American) completed the Weight and Lifestyle Inventory and a semistructured interview as part of a pre-surgery behavioral/psychological assessment. Diagnoses for NES and BED were based on graded diagnostic criteria. Results Percentages of participants who met diagnostic criteria for NES by interview were 1.9% for the strictest definition and 8.9% across all definitions of NES. After interview, full DSM-TR criteria for BED were met by 4.2%; an additional 1.4% reported binge eating at least once per week. Self-reported prevalence of NES and BED were higher. Those with NES or BED had significantly more symptoms of depression and a greater history of psychological complications than the remaining sample. Discussion The prevalence rates of NES and BED among this population of bariatric surgery candidates were lower than expected based on previous reports. Findings and hypotheses regarding lowered prevalence rates are discussed.
Choline PET for Monitoring Early Tumor Response to Photodynamic Therapy

Photodynamic therapy (PDT) is a relatively new therapy that has shown promise for treating various cancers in both preclinical and clinical studies. The present study evaluated the potential use of PET with radiolabeled choline to monitor early tumor response to PDT in animal models. Methods: Two human prostate cancer models (PC-3 and CWR22) were studied in athymic nude mice. A second-generation photosensitizer, phthalocyanine 4 (Pc 4), was delivered to each animal by a tail vein injection 48 h before laser illumination. Small-animal PET images with 11C-choline were acquired before PDT and at 1, 24, and 48 h after PDT. Time–activity curves of 11C-choline uptake were analyzed before and after PDT. The percentage of the injected dose per gram of tissue was quantified for both treated and control tumors at each time point. In addition, Pc 4-PDT was performed in cell cultures. Cell viability and 11C-choline uptake in PDT-treated and control cells were measured. Results: For treated tumors, normalized 11C-choline uptake decreased significantly 24 and 48 h after PDT, compared with the same tumors before PDT (P
Asymptotic freedom and confinement from type 0 string theory

We argue that there are generic solutions to the type 0 gravity equations of motion that are confining in the infrared and have log scaling in the ultraviolet. The background curvature generically diverges in the IR. Nevertheless, there exist solutions where higher order string corrections appear to be exponentially suppressed in the IR with respect to the leading type 0 gravity terms. For these solutions the tachyon flows to a fixed value. We show that the generic solutions lead to a long range linear quark potential, magnetic screening and a discrete glueball spectrum. We also estimate some WKB glueball mass ratios and compare them to ratios found using finite temperature models and lattice computations.
Dynamic Model Inversion Techniques for Breath-by-Breath Measurement of Carbon Dioxide from Low Bandwidth Sensors

Respiratory CO2 measurement (capnography) is an important diagnosis tool that lacks inexpensive and wearable sensors. This paper develops techniques to enable use of inexpensive but slow CO2 sensors for breath-by-breath tracking of CO2 concentration. This is achieved by mathematically modeling the dynamic response and using model-inversion techniques to predict input CO2 concentration from the slowly varying output. Experiments are designed to identify model-dynamics and extract relevant model-parameters for a solid-state room monitoring CO2 sensor. A second-order model that accounts for flow through the sensor's filter and casing is found to be accurate in describing the sensor's slow response. The corresponding model-inversion algorithm is however found to be susceptible to noise sources. Techniques to remove spurious noise, while retaining quality of estimate are developed. The resulting estimate is compared with a standard-of-care respiratory CO2 analyzer and shown to effectively track variation in breath-by-breath CO2 concentration. This methodology is potentially useful for measuring fast-varying inputs to any slow sensor.
Employee Stock Options

Abstract This paper examines the valuation of employee stock options (ESOs). Because ESOs are inalienable, the employee's optimal exercise policy differs from the policy a naive reading of the finance literature would suggest. The employee prefers to exercise options before maturity under certain conditions on risk aversion, investment opportunities, and wealth. Since the ESOs' cost to the employer depends on the employee's exercise policy, this finding has implications for changes to the accounting treatment of ESOs under this finding has implications for changes to the accounting treatment of ESOs under consideration by the Financial Accounting Standards Board. Numerical examples suggest the employer's cost is much less than the options' Black-Scholes value.
ASYMPTOTIC PROPERTIES OF SELF-NORMALIZED LINEAR PROCESSES WITH LONG MEMORY

In this paper we study the central limit theorem in its functional form for time series with long memory having independent innovations with infinite second moment. For the sake of applications we derive the self-normalized version of this theorem. The study is motivated by models arising in economical applications where often the linear processes have long memory, the innovations have long tails and coefficients are not summable.
Survey for Transiting Extrasolar Planets in Stellar Systems. IV. Variables in the Field of NGC 1245

The Survey for Transiting Extrasolar Planets in Stellar Systems (STEPSS) project is a search for planetary transits in open clusters. In this paper we analyze the STEPSS observations of the open cluster NGC 1245 to determine the variable-star content of the cluster. Out of 6787 stars observed with V < 22, of which ~870 are cluster members, we find 14 stars with clear intrinsic variability that are potential cluster members and 29 clear variables that are not cluster members. None of these variables have been previously identified. We present light curves, finder charts, and stellar/photometric data on these variable objects. Several of the interacting binaries have estimated distances consistent with the cluster distance determined from isochrone fits to the color-magnitude diagram. Four stars at the main-sequence turnoff of the cluster have light curves consistent with γ Doradus variability. If these γ Doradus candidates are confirmed, they represent the oldest and coolest members of this class of variable discovered to date.
DVS for On-Chip Bus Designs Based on Timing Error Correction

On-chip buses are typically designed to meet performance constraints at worst-case conditions, including process corner, temperature, IR-drop, and neighboring net switching pattern. This can result in significant performance slack at more typical operating conditions. In this paper, we propose a dynamic voltage scaling (DVS) technique for buses, based on a double sampling latch which can detect and correct for delay errors without the need for retransmission. The proposed approach recovers the available slack at non-worst-case operating points through more aggressive voltage scaling and tracks changing conditions by monitoring the error recovery rate. Voltage margins needed in traditional designs to accommodate worst-case performance conditions are therefore eliminated, resulting in a significant improvement in energy efficiency. The approach was implemented for a 6mm memory read bus operating at 1.5GHz (0.13 µm technology node) and was simulated for a number of benchmark programs. Even at the worst-case process and environment conditions, energy gains of up to 17% are achieved, with error recovery rates under 2.3%. At more typical process and environment conditions, energy gains range from 35% to 45%, with a performance degradation under 2%. An analysis of optimum interconnect architectures for maximizing energy gains with this approach shows that the proposed approach performs well with technology scaling.
How to Study a Tone Language, with Exemplification from Oku (Grassfields Bantu, Cameroon).

On numerous occasions I have been asked, “How does one study a tone language?” Or: “How can I tell if my language is tonal?” Even seasoned field researchers, upon confronting their first tone system, have asked me: “How do I figure out the number of tones I have?” When it comes to tone, colleagues and students alike often forget everything they’ve learned about discovering the phonology of a language and assume that tone is somehow different, that it requires different techniques or expertise. Some of this may derive from an incomplete understanding of what it means to be a tone system. Prior knowledge of possible tonal inventories, tone rules, and tonegrammar interfaces would definitely be helpful to a field researcher who has to decipher a tone system. However, despite such recurrent encounters, general works on tone seem not to answer these questions—specifically, they rarely tell you how to start and how to discover. I sometimes respond to the last question, “How do I figure out the number of tones I have?”, by asking in return, “Well, how would you figure out the number of vowels you have?” Hopefully the answer would be something like: “I would get a word list, starting with nouns, listen carefully, transcribe as much detail as I can, and then organize the materials to see if I have been consistent.” (I will put off until §5 commentary concerning the use of speech software as an aid in linguistic discovery.) Although I don’t think the elicitation techniques that one applies in studying segmental vs. tonal phonology are really very different, what is needed is a general discussion and illustration of how tonologists go about their work from beginning to end. My goal here is to share my personal experience with tonal elicitation in hopes that it will be useful to field researchers and students who are lucky enough to face an unknown tone system. I will not claim that every tonologist adopts the same strategies as I do, some of which I learned directly or indirectly from my teacher, Wm. E. Welmers, but I believe that most Africanists do. Logically, there are three separate tasks that one must take up in studying a tone system from scratch. Since these are necessarily ordered, with each one feeding into the next, I will refer to the three tasks as stages: (i) In Stage I the goal is to determine the surface tonal contrasts. This is first done by considering words in isolation. (ii) In Stage II the goal is to discover any tonal alternations (“morphotonemics”) which may exist in the language. This can be done either by putting words together to make short phrases or by eliciting paradigms. (iii) Stage III comprises the tonal analysis itself, the interpretation of what has been discovered in Stages I and II. At this point one typically draws on theoretical constructs and formal devices, e.g. autosegmental notation, to help express one’s insights as to how the tone system works. UC Berkeley Phonology Lab Annual Report (2010)
Grocery Retailer Pricing Behavior for California Avocados with Implications for Industry Promotion Strategies

Rising concentration and consolidation of sales among large supermarket chains in the U.S. and other countries, due in part to a recent wave of mergers in food retailing, have made retailers' role in the food industry a topical issue. Using a unique micro dataset, this paper investigates retailer pricing issues for avocados, a key California specialty commodity, and analyzes the implications of retailer pricing behavior for the effectiveness of avocado industry advertising programs. The methodologies developed and the results achieved in this study should have broad applications across the produce sector, the food industry, and the grocery retail market. We find that retail prices for avocados are highly dispersed both spatially and temporarily. The analysis also illustrates the existence of a "regular" retail price for avocados. Downward deviations from the "regular" price dominated changes in retail prices, in particular, temporary price reductions accounted for 27 percent of retail price variations. The study examines the effects of fundamental cost and demand factors on determination of retail prices. We conclude that costs are not a primary factor in setting retail prices for avocados. Retailers' sales strategies, which reflect decreases in retail margins rather than decreases in costs, explained much of the observed temporary price reductions for avocados. Retail prices for avocados also exhibited countercyclical movements over seasonal demand cycles. The findings provide support for Lal and Matutes' (1994) hypothesis that retailers reduce prices or margins during a product's high-demand periods. We investigate how retailers respond to industry promotions and, in turn, how retailer response enhances or vitiates the effectiveness of industry promotions. The approach of "Difference-in-Difference" is employed to evaluate the effects of the California Avocado Commission's (CAC) promotion programs on retail pricing and sales. The analysis demonstrates that the radio campaign and outdoor advertisements were successful in raising avocado sales. There is no evidence that retailers charged higher prices during the CAC's promotions. Nonetheless, the CAC's promotion programs could be enhanced if retailers were better informed about the advertising campaigns. Other noteworthy results include the fact that retail margins increased significantly as shipment volumes increased, indicating the presence of retailer oligopsony power. Also notable was the rather strong evidence that retail prices were significantly lower as a function of the amount of avocados imported from Chile and Mexico, meaning that consumers have benefited from trade liberalization for avocados.
Numerical Studies on the Geomechanical Stability of Hydrate-Bearing Sediments

The thermal and mechanical loading of oceanicHydrate-Bearing Sediments (HBS) can result in hydrate dissociation and asignificant pressure increase, with potentially adverse consequences onthe integrity and stability of the wellbore assembly, the HBS, and thebounding formations. The perception of HBS instability, coupled withinsufficient knowledge of their geomechanical behavior and the absence ofpredictive capabilities, have resulted in a strategy of avoidance of HBSwhen locating offshore production platforms, and can impede thedevelopment of hydrate deposits as gas resources.In this study weinvestigate in three cases of coupled hydraulic, thermodynamic andgeomechanical behavior of oceanic hydrate-bearing sediments. The firstinvolves hydrate heating as warm fluids from deeper conventionalreservoirs ascend to the ocean floor through uninsulated pipesintersecting the HBS. The second case describes system response duringgas production from a hydrate deposit, and the third involves mechanicalloading caused by the weight of structures placed on the ocean flooroverlying hydrate-bearing sediments.For the analysis of the geomechanicalstability of HBS, we developed and used a numerical model that integratesa commercial geomechanical code and a simulator describing the coupledprocesses of fluid flow, heat transport and thermodynamic behavior in theHBS. Our simulation results indicate that the stability of HBS in thevicinity of warm pipes may be significantly affected, especially if thesediments are unconsolidated andmore » more compressible. Gas production fromoceanic deposits may also affect the geomechanical stability of HBS underthe conditions that are deemed desirablefor production. Conversely, theincreased pressure caused by the weight of structures on the ocean floorincreases the stability of underlying hydrates.« less
A workshop approach: Instructional strategies for working within the constraints of field experiences in elementary science

Successful experiences teaching science early on can impact teachers’ continued teaching of science; therefore, field-based teaching experiences are critical to preservice teacher education in science. Such field experiences may be subject to constraints, however, such as limited time, which prevent preservice teachers from experiencing this early success. In this paper, the author describes an existing field-based teaching experience and her personal experiences implementing an innovative approach while working within limited time constraints. The workshop approach used in the field experience provided preservice teachers with the opportunity to readjust ineffective strategies and refine their teaching while developing techniques for working with students of different grade levels.
Housing Market Spillovers: Evidence from the End of Rent Control in Cambridge, Massachusetts

We measure the capitalization of housing market externalities into residential housing values by studying the unanticipated elimination of stringent rent controls in Cambridge, Massachusetts, in 1995. Pooling data on the universe of assessed values and transacted prices of Cambridge residential properties between 1988 and 2005, we find that rent decontrol generated substantial, robust price appreciation at decontrolled units and nearby never-controlled units, accounting for a quarter of the $7.8 billion in Cambridge residential property appreciation during this period. The majority of this contribution stems from induced appreciation of never-controlled properties. Residential investment explains only a small fraction of the total.
Optimization study of stacked micro-channel heat sinks for micro-electronic cooling

With smaller inlet flow velocity, a micro-channel stack requires less pumping power to remove a certain rate of heat than a single-layered micro-channel, because it provides a larger heat transfer area. A simple thermal resistance network model was developed to evaluate the overall thermal performance of a stacked micro-channel heat sink. Based on this simple model, in this study, a single objective minimization of overall thermal resistance is carried out using genetic algorithms. The aspect ratio, fin thickness and the ratio of channel width to fin thickness are the variables to be optimized, subject to constraints of maximum pressure drop (4 bar) and maximum volumetric flow rate (1000 ml/min). During the optimization, the overall dimensions, number of layers and pumping power (product of pressure drop and flow rate) are fixed. The study indicates that reduction in thermal resistance can be achieved by optimizing the channel configuration. The effects of number of layers in the stack, pumping power per unit area, and the channel length are also investigated.
The speed of a biased walk on a Galton–Watson tree without leaves is monotonic with respect to progeny distributions for high values of bias

Nous considerons des marches aleatoires biaisees sur deux arbres de Galton–Watson sans feuilles $\mathrm{GW}(P_{1})$ et $\mathrm{GW}(P_{2})$ ayant des lois de reproduction respectivement $P_{1}$ et $P_{2}$, deux lois supportees par les entiers positifs telles que $P_{1}$ domine stochastiquement $P_{2}$. Nous prouvons que la vitesse de la marche sur $\mathrm{GW}(P_{1})$ est superieure ou egale a celle sur $\mathrm{GW}(P_{2})$ si le biais est plus grand qu’un seuil dependant de $P_{1}$ et $P_{2}$. Ceci repond partiellement a une question posee par Ben Arous, Fribergh et Sidoravicius (Comm. Pure Appl. Math. 67 (2014) 519–530).
Small genus knots in lens spaces have small bridge number

In a lens space X of order r a knot K representing an element of the fundamental group 1X S Z=rZ of order s r contains a connected orientable surface S properly embedded in its exterior X N.K/ such that @S intersects the meridian of K minimally s times. Assume S has just one boundary component. Let g be the minimal genus of such surfaces for K , and assume s 4g 1 . Then with respect to the genus one Heegaard splitting of X , K has bridge number at most 1 .
Systematic vs. non-systematic algorithms for solving the MPE task

The paper explores the power of two systematic Branch and Bound search algorithms that exploit partition-based heuristics, BBBT (a new algorithm for which the heuristic information is constructed during search and allows dynamic variable/value ordering) and its predecessor BBMB (for which the heuristic information is pre-compiled) and compares them against a number of popular local search algorithms for the MPE problem as well as against the recently popular iterative belief propagation algorithms. We show empirically that the new Branch and Bound algorithm, BBBT demonstrates tremendous pruning of the search space far beyond its predecessor, BBMB which translates to impressive time saving for some classes of problems. Second, when viewed as approximation schemes, BBBT/BBMB together are highly competitive with the best known SLS algorithms and are superior, especially when the domain sizes increase beyond 2. The results also show that the class of belief propagation algorithms can outperform SLS, but they are quite inferior to BBMB/BBBT. As far as we know, BBBT/BBMB are currently among the best performing algorithms for solving the MPE task.
Comparison of adjoint-based and feature-based grid adaptation for functional outputs

Adjoint-based and feature-based grid adaptive strategies are compared for their robustness and effectiveness in improving the accuracy of functional outputs such as lift and drag coefficients. The output-based adjoint approach strives to improve the adjoint error estimates that relate the local residual errors to the global error in an output function via adjoint variables as weight functions. A conservative adaptive indicator that takes into account the residual errors in both the primal (flow) and dual (adjoint) solutions is implemented for the adjoint approach. The physics-based feature approach strives to identify and resolve significant features of the flow to improve functional accuracy. Adaptive indicators that represent expansions and compressions in the flow direction and gradients normal to the flow direction are implemented for the feature approach. The adaptive approaches are compared for functional outputs of three-dimensional arbitrary Mach number flow simulations on mixed-element unstructured meshes. Grid adaptation is performed with h-refinement and results are presented for inviscid, laminar and turbulent flows. Copyright © 2006 John Wiley & Sons, Ltd.
An integrated strategy for efficient vector construction and multi-gene expression in Plasmodium falciparum

The construction of plasmid vectors for transgene expression in the malaria parasite, Plasmodium falciparum, presents major technical hurdles. Traditional molecular cloning by restriction and ligation often yields deletions and re-arrangements when assembling low-complexity (A + T)-rich parasite DNA. Furthermore, the use of large 5′- and 3′- untranslated regions of DNA sequence (UTRs) to drive transgene transcription limits the number of expression cassettes that can be incorporated into plasmid vectors. To address these challenges, two high fidelity cloning strategies, namely yeast homologous recombination and the Gibson assembly method, were evaluated for constructing P. falciparum vectors. Additionally, some general rules for reliably using the viral 2A-like peptide to express multiple proteins from a single expression cassette while preserving their proper trafficking to various subcellular compartments were assessed. Yeast homologous recombination and Gibson assembly were found to be effective strategies for successfully constructing P. falciparum plasmid vectors. Using these cloning methods, a validated family of expression vectors that provide a flexible starting point for user-specific applications was created. These vectors are also compatible with traditional cloning by restriction and ligation, and contain useful combinations of commonly used features for enhancing plasmid segregation and site-specific integration in P. falciparum. Additionally, application of a 2A-like peptide for the synthesis of multiple proteins from a single expression cassette, and some rules for combinatorially directing proteins to discrete subcellular compartments were established. A set of freely available, sequence-verified and functionally validated parts that offer greater flexibility for constructing P. falciparum vectors having expanded expression capacity is provided.
Heterotic Strings with Torsion

In this paper we describe the heterotic dual of the type-IIB theory compactified to four dimensions on a toroidal orientifold in the presence of fluxes. The type-IIB background is most easily described in terms of an -theory compactification on a four-fold. The heterotic dual is obtained by performing a series of U-dualities. We argue that these dualities preserve supersymmetry and that the supergravity description is valid after performing them. The heterotic string is compactified on a manifold that is no longer Kahler and has torsion. These manifolds have to satisfy a number of constraints, for example, existence of an holomorphic three-form, size limits, torsional equations etc. We give an explicit form of the background and study the constraints associated to them.
Partial Privatization and Firm Performance

Most privatization programs begin with a period of partial privatization in which only non-controlling shares of firms are sold on the stock market. Since management control is not transferred to private owners it is widely contended that partial privatization has little impact. This perspective ignores the role that the stock market can play in monitoring and rewarding managerial performance even when the government remains the controlling owner. Using data on Indian state-owned enterprises we find that partial privatization has a positive impact on profitability, productivity, and investment. WIDESPREAD PRIVATIZATION IN RECENT DECADES has generated a large empirical literature concerning the effect of ownership on firm performance. Most studies find that privatization has a positive impact on the profitability and efficiency of firms (see Megginson and Netter (2001) for a recent survey). 1 The firms in these studies have had a majority of their assets privatized and control rights have been transferred from the government to private owners. Surprisingly, little is known about the effect of partial privatization where the government remains the controlling owner. This paper seeks to address this gap in the literature by investigating whether the performance of state-owned enterprises in India is affected by the sale of non-controlling equity stakes on the stock market.
Fast maximum-likelihood decoding of the golden code

Because each golden code codeword conveys four information symbols from an M-ary QAM alphabet, the complexity of an exhaustive-search decoder is proportional to M4. In this paper we prove that the golden code is fast-decodable, meaning that maximum-likelihood decoding is possible with a worst-case complexity proportional to only M2.5. The golden code retains its fast-decodable property regardless of whether the channel varies with time. We also present an efficient implementation of a fast maximum-likelihood decoder that exhibits a low average complexity.
Linear life expectancy regression with censored data

SUMMARY In the statistical literature, life expectancy is usually characterised by the mean residual life function. Regression models are thus needed to study the association between the mean residual life functions and their covariates. In this paper, we consider a linear mean residual life model and develop inference procedures in the presence of potential censoring. The new model and inference procedures are applied to the Stanford heart transplant data. Semiparametric efficiency calculations and information bounds are also considered.
Computational studies of colicin insertion into membranes: The closed state

Colicins are water-soluble toxins that, upon interaction with membranes, undergo a conformational change, insert, and form pores in them. Pore formation activity is localized in a bundle of 10 α-helices named the pore-forming domain (PFD). There is evidence that colicins attach to the membrane via a hydrophobic hairpin embedded in the core of the PFD. Two main models have been suggested for the membrane-bound state: penknife and umbrella, differing in regard to the orientation of the hydrophobic hairpin with respect to the membrane. The arrangement of the amphipathic helices has been described as either a compact three-dimensional structure or a two-dimensional array of loosely interacting helices on the membrane surface. Using molecular dynamics simulations with an implicit membrane model, we studied the structure and stability of the conformations proposed above for four colicins. We find that colicins are initially driven towards the membrane by electrostatic interactions between basic residues and the negatively charged membrane surface. They do not have a unique binding orientation, but in the predominant orientations the central hydrophobic hairpin is parallel to the membrane. In the inserted state, the estimated free energy tends to be lower for the compact arrangements of the amphipathic helix, but the more expanded ones are in better agreement with experimental distance distributions. The difference in energy between penknife and umbrella conformations is small enough for equilibrium to exist between them. Elongation of the hydrophobic hairpin helices and membrane thinning were found unable to produce stabilization of the transmembrane configuration of the hydrophobic hairpin.
Cryoablation of ventricular tachycardia guided by return cycle mapping after entrainment

Abstract Background: Although the implantable cardioverter-defibrillator effectively prevents sudden cardiac death, patients are still prone to recurrence of ventricular tachyarrhythmias. Electrophysiologically guided surgery is the most effective modality in abolishing ventricular tachycardia, having a lower recurrence rate than pharmacologic therapy or catheter ablation. Return cycle mapping after entrainment has been shown to localize the central common pathway, which is the target region for ablation, without pacing at the pathway or recording the potentials from the pathway. Methods: To determine the accuracy and usefulness of return cycle mapping in surgery for ventricular tachycardia, we cryoablated 8 morphologies of ventricular tachycardia induced in postinfarction dogs with the guidance of return cycle mapping. The ventricular tachycardia was entrained from 3 to 5 different epicardial sites at a paced cycle length 10 to 20 ms shorter than the ventricular tachycardia cycle length and the epicardium was mapped with 61 unipolar electrodes during cessation of entrainment to construct return cycle maps. The return cycle was determined by subtracting the first activation time from the second activation time after the last stimulus in each electrode location, and the maps were then displayed on a computer. Results: The total analysis process was completed within 3 minutes by means of a computer with custom-made programs. The activation map during ventricular tachycardia did not localize the central common pathway in any morphology of ventricular tachycardia, because the pattern of activation was concentric and diastolic potentials were not recorded. Cryoablation of the region where the isotemporal lines of the return cycle equal to the ventricular tachycardia cycle length intersected resulted in termination of ventricular tachycardia in all morphologies. The intersection was 26 ± 9 mm from the earliest activation site. Epicardial mapping with 253 electrodes during cryothermia showed that the region localized by return cycle mapping was the central common pathway sandwiched between the lines of conduction block and that the cryolesion connected the lines of block, blocked the rotating wave front, and resulted in termination of the ventricular tachycardia. Conclusion: Return cycle mapping provides an accurate and rapid means of localizing the central common pathway without the need for recording potentials from the pathway or pacing at the pathway in ablation for ventricular tachycardia. (J Thorac Cardiovasc Surg 2001;121:249-58)
3D integration for energy efficient system design

Technology scaling will continue, doubling transistor integration capacity every two years, providing billions of transistors to enable novel systems. 3D integration technology will open the doors even further, changing the landscape, allowing heterogeneous integration of diverse technologies, with abundance of energy efficient interconnects to realize affordable complex systems that will continue to deliver higher performance. This paper presents how to exploit this new technology for energy efficient system designs.
Negative Campaign Advertising: Demobilizer or Mobilizer?

Author(s): Wattenberg, Martin P.; Brians, Craig Leonard | Abstract: With political campaigns becoming increasingly adversarial, scholars have recently given some much-needed attention to the impact of negative advertising on turnout.In a widely recognized Review article and subsequent book, Ansolabehere and his colleagues (1994, 1995) contend that attack advertising drives potential voters away from the polls. We dispute the generalizability of these claims outside of the experimental setting. Using NES survey data as well aggregate sources, we subject this previous research to rigorous real-world testing. The survey data directly contradict Ansolabehere et al.'s findings, yielding evidence of a turnout advantage for those recollecting negative presidential campaign advertising. In attempting to replicate Ansolabehere et al’s earlier aggregate results we uncover quite significant discrepancies and inconsistencies in their dataset. This analysis leads to the conclusion that their aggregate study is hopelessly flawed. We must conclude that attack advertising’s demobilization dangers are greatly exaggerated by Ansolabehere et al., while they completely miss negative political advertising’s turnout benefits -- at least in voters’ own context.
Smoothing splines with varying smoothing parameter

This paper considers the development of spatially adaptive smoothing splines for the estimation of a regression function with nonhomogeneous smoothness across the domain. Two challenging issues arising in this context are the evaluation of the equivalent kernel and the determination of a local penalty. The penalty is a function of the design points in order to accommodate local behaviour of the regression function. We show that the spatially adaptive smoothing spline estimator is approximately a kernel estimator, and that the equivalent kernel is spatially dependent. The equivalent kernels for traditional smoothing splines are a special case of this general solution. With the aid of the Green's function for a two-point boundary value problem, explicit forms of the asymptotic mean and variance are obtained for any interior point. Thus, the optimal roughness penalty function is obtained by approximately minimizing the asymptotic integrated mean squared error. Simulation results and an application illustrate the performance of the proposed estimator. Copyright 2013, Oxford University Press.
Two problems on independent sets in graphs

Let i t ( G ) denote the number of independent sets of size t in a graph G . Levit and Mandrescu have conjectured that for all bipartite G the sequence ( i t ( G ) ) t ? 0 (the independent set sequence of G ) is unimodal. We provide evidence for this conjecture by showing that this is true for almost all equibipartite graphs. Specifically, we consider the random equibipartite graph G ( n , n , p ) , and show that for any fixed p ? ( 0 , 1 ] its independent set sequence is almost surely unimodal, and moreover almost surely log-concave except perhaps for a vanishingly small initial segment of the sequence. We obtain similar results for p = ? ? ( n - 1 / 2 ) .We also consider the problem of estimating i ( G ) = ? t ? 0 i t ( G ) for G in various families. We give a sharp upper bound on the number of independent sets in an n -vertex graph with minimum degree ? , for all fixed ? and sufficiently large n . Specifically, we show that the maximum is achieved uniquely by K ? , n - ? , the complete bipartite graph with ? vertices in one partition class and n - ? in the other.We also present a weighted generalization: for all fixed x 0 and ? 0 , as long as n = n ( x , ? ) is large enough, if G is a graph on n vertices with minimum degree ? then ? t ? 0 i t ( G ) x t ? ? t ? 0 i t ( K ? , n - ? ) x t with equality if and only if G = K ? , n - ? . Highlights? The stable set sequence of the random equibipartite graph is almost surely unimodal. ? Apart from perhaps a short initial segment, it is almost surely log-concave. ? The n vertex graph with minimum degree d with the most stable sets is K ( d , n - d ) .
Asymmetric catalysis with "planar-chiral" heterocycles*

Planar-chiral heterocycles serve as effective enantioselective nucleophilic catalysts and as useful ligands for asymmetric metal-catalyzed processes.