cssi/SciSciGPT-SciSciNet huggingface dataset:
Active clustering: Robust and efficient hierarchical clustering using adaptively selected similarities

Hierarchical clustering based on pairwise similarities is a common tool used in a broad range of scientific applications. However, in many problems it may be expensive to obtain or compute similarities between the items to be clustered. This paper investigates the hierarchical clustering of N items based on a small subset of pairwise similarities, significantly less than the complete set of N (N − 1)/2 similarities. First, we show that if the intracluster similarities exceed intercluster similarities, then it is possible to correctly determine the hierarchical clustering from as few as 3N log N similarities. We demonstrate this order of magnitude savings in the number of pairwise similarities necessitates sequentially selecting which similarities to obtain in an adaptive fashion, rather than picking them at random. We then propose an active clustering method that is robust to a limited fraction of anomalous similarities, and show how even in the presence of these noisy similarity values we can resolve the hierarchical clustering using only O ( N log 2 N ) pairwise similarities.
Convenient synthesis of crown ethers containing a hydrazine moiety

Abstract A new class of crown ethers containing a hydrazine moiety was synthesized in only 2, 3, or 4 steps starting from 1,2-diacetylhydrazine or 1,2-diethylhydrazine. Hydrazino-crown ethers with 2 or 4 nitrogen atoms in the ring were obtained by reacting the hydrazine derivatives with 1,11-diiodo-(or dichloro)-3,6,9-trioxaundecane, 4-allyloxymethyl-1,8-diiodo-3,6-dioxaoctane, 3-chloro-2-chloromethyl-1-propene, 1,10-dibenzyl-1,10-diaza-3,7-dioxadecane or diglycolyl dichloride (followed by reduction). The diazahydrazino-19-crown-6 compound formed a complex with methylammonium chloride.
Influence of parent characteristics and disease outcome framing on HPV vaccine acceptability among rural, Southern women.

Objective A new prophylactic vaccine protects against infection with HPV types that cause many cervical cancers and genital warts. This study explored the impact of framing the vaccine’s benefits, with respect to the disease outcome being prevented, on women’s HPV vaccination intentions for themselves and for an adolescent daughter.
Semantic email: theory and applications

This paper investigates how the vision of the Semantic Web can be carried over to the realm of email. We introduce a general notion of semantic email, in which an email message consists of a structured query or update coupled with corresponding explanatory text. Semantic email opens the door to a wide range of automated, email-mediated applications with formally guaranteed properties. In particular, this paper introduces a broad class of semantic email processes. For example, consider the process of sending an email to a program committee, asking who will attend the PC dinner, automatically collecting the responses, and tallying them up. We define both logical and decision-theoretic models where an email process is modeled as a set of updates to a data set on which we specify goals via certain constraints or utilities. We then describe a set of inference problems that arise while trying to satisfy these goals and analyze their computational tractability. In particular, we show that for the logical model it is possible to automatically infer which email responses are acceptable w.r.t. a set of constraints in polynomial time, and for the decision-theoretic model it is possible to compute the optimal message-handling policy in polynomial time. In addition, we show how to automatically generate explanations for a process's actions, and identify cases where such explanations can be generated in polynomial time. Finally, we discuss our publicly available implementation of semantic email and outline research challenges in this realm.
Work and Home Location: Possible Role of Social Networks.

This research explores to what extent people’s work locations are similar to that of those who live around them. Using the Longitudinal Employer-Household Dynamics data set and the 2000 decennial census, we investigate the home and work locations of different census block residents in the Twin Cities (Minneapolis–St. Paul) metropolitan area. Our aim is to investigate if people who share a residence neighborhood also share work locations to a degree beyond what would be explained by distance and opportunities around them. Using quadratic assignment procedure we find a significantly higher joint home and work location choice among residents in eight areas selected for this investigation. Further, using data for the entire metropolitan area, we show what socio-demographic variables are associated with higher levels of home-work co-location. We hypothesize that a possible reason for the observed patterns is the role neighborhood level and work place social networks play in locating jobs and residences respectively.
Imports From China and Food Safety Issues

The U.S. Food and Drug Administration’s (FDA) increased attention to food imports from China is an indicator of safety concerns as imported food becomes more common in the United States. U.S. food imports from China more than tripled in value between 2001 and 2008. Addressing safety risks associated with these imports is difficult because of the vast array of products from China, China’s weak enforcement of food safety standards, its heavy use of agricultural chemicals, and its considerable environmental pollution. FDA import refusal data highlight food safety problems that appear to recur in trade and where FDA has focused its import alerts and monitoring efforts. FDA refusals of food shipments from China suggest recurring problems with “filth,” unsafe additives, labeling (typically introduced in food processing and handling), and veterinary drug residues in fish and shellfish (introduced at the farm). Chinese authorities try to control food export safety by certifying exporters and the farms that supply them. However, monitoring such a wide range of products for the different hazards that can arise at varying points in the supply chain is a difficult challenge for Chinese and U.S. officials.
Informed and Strategic Order Flow in the Bond Markets

We study the role played by private and public information in the process of price formation in the U.S. Treasury bond market. To guide our analysis, we develop a parsimonious model of speculative trading in the presence of two realistic market frictions—information heterogeneity and imperfect competition among informed traders—and a public signal. We test its equilibrium implications by analyzing the response of two-year, five-year, and ten-year U.S. bond yields to order flow and real-time U.S. macroeconomic news. We find strong evidence of informational effects in the U.S. Treasury bond market: unanticipated order flow has a significant and permanent impact on daily bond yield changes during both announcement and nonannouncement days. Our analysis further shows that, consistent with our stylized model, the contemporaneous correlation between order flow and yield changes is higher when the dispersion of beliefs among market participants is high and public announcements are noisy.
Sub-Finsler geometry in dimension three

Abstract We define the notion of sub-Finsler geometry as a natural generalization of sub-Riemannian geometry with applications to optimal control theory. We compute a complete set of local invariants, geodesic equations, and the Jacobi operator for the three-dimensional case and investigate homogeneous examples.
First-order stable model semantics and first-order loop formulas

Lin and Zhao's theorem on loop formulas states that in the propositional case the stable model semantics of a logic program can be completely characterized by propositional loop formulas, but this result does not fully carry over to the first-order case. We investigate the precise relationship between the first-order stable model semantics and first-order loop formulas, and study conditions under which the former can be represented by the latter. In order to facilitate the comparison, we extend the definition of a first-order loop formula which was limited to a nondisjunctive program, to a disjunctive program and to an arbitrary first-order theory. Based on the studied relationship we extend the syntax of a logic program with explicit quantifiers, which allows us to do reasoning involving non-Herbrand stable models using first-order reasoners. Such programs can be viewed as a special class of first-order theories under the stable model semantics, which yields more succinct loop formulas than the general language due to their restricted syntax.
Heat flow and the structure of Precambrian lithosphere

Abstract Studies of heat flow from Precambrian terrains have demonstrated three empirical relationships; a temporal relationship between heat flow and tectonic age, a spatial pattern between heat flow and the proximity of Archean cratons, and a temporal relationship between heat flow and the age of lithosphere stabilization. In the first relationship, heat flow is inversely related to tectonic age. The second pattern is characterized by low heat flow from Archean cratons and Proterozoic terrains adjacent to cratonic margins (pericratonic terrains), and higher heat flow from Proterozoic terrains that are more than a few hundred kilometers from a craton. In the third pattern, heat flow decreases as the age of stabilization of the lithosphere increases. A number of interpretations of Precambrian heat flow have been offered to explain one or more of these relationships. The simple cooling of a thermal boundary layer predicts essentially no change in heat flow in terrains older than ∼1.5 Ga, and therefore does not likely provide a comprehensive framework for the interpretation of Precambrian heat flow. By contrast, two other interpretations, (1) thicker lithosphere beneath Archean terrains than beneath Proterozoic terrains, and (2) greater heat production in Proterozoic crust than in Archean crust, when combined with the special structural configuration of sutures, can both contribute to the spatial and temporal heat flow distributions. Xenolith thermobarometry constraints on lithospheric temperatures, however, limit the contribution of age-dependent crustal heat production, and therefore at least part of the heat flow distributions derive from variations in lithosphere thickness.
Structural holes and managerial performance: Identifying the underlying mechanisms

Structural holes theory suggests a variety of possible explanations for the empirically observed relationship between structural holes and individual managerial performance. However, little has been done to disentangle one mechanism from another. This paper empirically tests a mediated moderation model that distinguishes between the five different theoretical mechanisms: autonomy, competition, information brokering, opportunity recognition and innovativeness. The findings suggest that of these five theoretical causal motors, innovativeness plays a key role in linking network structure and network content to performance.
Infectious diseases, public policy, and the marriage of economics and epidemiology

The assumption of rational choice helps in understanding how people respond to infectious diseases. People maximize their well- being by choosing levels of prevention and therapy subject to the constraints faced. Objectives and constraints are numerous, necessitating tradeoffs. For example, this approach predicts how people respond to changes in the risk of infection and to the availability of diagnostic tests. The combination of individual rationality with epidemiological models of infection dynamics predicts whether individual choices about infectious disease prevention and therapies produce the best possible social outcomes. If not, individuals choices generate rationales for government interventions to influence the levels of preventive and therapeutic activities. Optimal policy usually means accepting endemic infection, but at a level lowered by a coordinated package of interventions. Economics combined with epidemiology provides much qualitative guidance on the design of such packages, including immunization programs.
Empirical explorations of the logic theory machine: a case study in heuristic

This paper is a case study in problem solving, representing part of a program of research on complex information-processing systems. We have specified a system for finding proofs of theorems in elementary symbolic logic, and by programming a computer to these specifications, have obtained empirical data on the problem-solving process in elementary logic. The program is called the Logic Theory Machine (LT); it was devised to learn how it is possible to solve difficult problems such as proving mathematical theorems, discovering scientific laws from data, playing chess, or understanding the meaning of English prose.
Information fusion with topological event spaces

We develop a novel information fusion scheme based on topological event space, viewed as a distributive lattice. We discuss the advantages of topological modeling and compare our approach to the existing Bayesian, Dempster-Shafer, and Dezert-Smarandache approaches. The proposed scheme is described in detail and illustrated with an example of fusion of three sensors in the presence of missing information.
{Mn14W48} aggregate: the perspective of isopolyanions as ligands

The assembly of a tetradeca-manganese magnetic cluster [Mn(14)W(48)O(192)H(20)](26-), containing two high spin Mn(7) cores and supported exclusively by isopolytungstate ligands, demonstrates the promising perspective of using "defect" isopolyanions as ligands/synthons to construct large aggregated structures and model the surface deposition of molecular magnets.
Preparation of 4'-substituted thymidines by substitution of the thymidine 5'-esters.

tert-Butyl thymidylate 3 was prepared from thymidine 1 in six steps and 67% overall yield. When the lithium trianion of 3 (prepared by treatment of 3 with excess LDA and then excess tert-butyllithum) is reacted with electrophiles, trapping occurs stereoselectively from either the α- or β-face depending on the electrophile (Scheme 1). Deuterioacetic acid in deuteriomethanol affords mainly the α-deuterated product (4a/4b = 2.4:1) while all other electrophiles, e.g., phenylselenenyl chloride, allyl bromide, and N-fluorobenzenesulfonimide (NFSI), give predominately (or completely) the products of attack from the β-face (5bcd/4bcd = 3.7:1 to 100:0). The structures of the products were determined by coupling constant analysis of both the initial compounds and the diols 6bcd prepared by ester reduction and by formation of the acetonides 7bc. The methyl ester of the 3‘-epimer of thymidylic acid 9 was also prepared from thymidine 1 in nine steps and 74% overall yield. When the lithium trianion of 9 (prepared by tr...
High-rate Plastic Deformation of Nanocrystalline Tantalum to Large Strains: Molecular Dynamics Simulation

Recent advances in the ability to generate extremes of pressure and temperature in dynamic experiments and to probe the response of materials has motivated the need for special materials optimized for those conditions as well as a need for a much deeper understanding of the behavior of materials subjected to high pressure and/or temperature. Of particular importance is the understanding of rate effects at the extremely high rates encountered in those experiments, especially with the next generation of laser drives such as at the National Ignition Facility. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum to investigate the processes associated with plastic deformation for strains up to 100%. We use initial atomic configurations that were produced through simulations of solidification in the work of Streitz et al [Phys. Rev. Lett. 96, (2006) 225701]. These 3D polycrystalline systems have typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. This analysis technique is robust and fast, and has been used to compute the orientations on the fly during our parallel MD simulations on supercomputers. We find both dislocation and twinning processes are important, and they interact in the weak strain hardening in these extremely fine-grained microstructures.
Synthesis, Structure, and Bonding Analysis of the Polar Intermetallic Phase Ca2Pt2Cd

The polar intermetallic phase Ca2Pt2Cd was discovered during explorations of the Ca-Pt-Cd system. The compound was synthesized by high temperature reactions, and its structure refined by single-crystal X-ray diffraction as orthorhombic, Immm, a = 4.4514(5), b = 5.8415(6), c = 8.5976(9) A, Z = 2. The structure formally contains infinite, planar networks of [Pt2Cd]4– along the ab plane, which can be described as tessellation of six and four-member rings of the anions, with cations stuffed between the anion layers. The infinite condensed platinum chains show a substantial long–short distortion of 0.52 A, an appreciable difference between Ca2Pt2Cd (26 valence electrons) and the isotypic but regular Ca2Cu2Ga (29 VE). The relatively large cation proportion diminishes the usual dominance of polar (Pt–Cd) and 5d–5d (Pt–Pt) contributions to the total Hamilton populations.
Cyclotomic FFTs With Reduced Additive Complexities Based on a Novel Common Subexpression Elimination Algorithm

In this paper, we first propose a novel common subexpression elimination (CSE) algorithm for matrix-vector multiplications over characteristic-2 fields. As opposed to previously proposed CSE algorithms, which usually focus on complexity savings due to recurrences of subexpressions, our CSE algorithm achieves two types of complexity reductions, differential savings and recurrence savings, by taking advantage of the cancellation property of characteristic-2 fields. Using our CSE algorithm, we reduce the additive complexities of cyclotomic fast Fourier transforms (CFFTs). Using a weighted sum of the numbers of multiplications and additions as a metric, our CFFTs achieve smaller total complexities than previously proposed CFFTs and other FFTs, requiring both fewer multiplications and fewer additions in many cases.
Carbohydrate post-glycosylational modifications

Carbohydrate modification is a common phenomenon in nature. Many carbohydrate modifications such as some epimerization, O-acetylation, O-sulfation, O-methylation, N-deacetylation, and N-sulfation, take place after the formation of oligosaccharide or polysaccharide backbones. These modifications can be categorized as carbohydrate post-glycosylational modifications (PGMs). Carbohydrate PGMs further extend the complexity of the structures and the synthesis of carbohydrates and glycoconjugates. They also increase the capacity of the biological regulation that is achieved by finely tuning the structures of carbohydrates. Developing efficient methods to obtain structurally defined naturally occurring oligosaccharides, polysaccharides, and glycoconjugates with carbohydrate PGMs is essential for understanding the biological significance of carbohydrate PGMs. Combined with high-throughput screening methods, synthetic carbohydrates with PGMs are invaluable probes in structure–activity relationship studies. We illustrate here several classes of carbohydrates with PGMs and their applications. Recent progress in chemical, enzymatic, and chemoenzymatic syntheses of these carbohydrates and their derivatives are also presented.
The ETA-II induction linac as a high-average-power FEL driver☆

Abstract The Experimental Test Accelerator II (ETA-II) is the first induction linac designed specifically to FEL requirements. It is primarily intended to demonstrate induction accelerator technology for high-average-power, high-brightness electron beams, and will be used to drive a 140 and 250 GHz microwave FEL for plasma heating experiments in the Microwave Tokamak Experiment (MTX) at LLNL. Its features include high-vacuum design which allows the use of an intrinsically bright dispenser cathode, induction cells designed to minimize BBU growth rate, and careful attention to magnetic alignment to minimize radial sweep due to beam corkscrew. The use of magnetic switches allows high-average-power operation. At present ETA-II is being used to drive 140 GHz plasma heating experiments. These experiments require nominal beam parameters of 6 MeV energy, 2 kA current, 20 ns pulse width and a brightness of 1 × 108 A/(m rad)2 at the wiggler with a pulse repetition frequency (prf) of 0.5 Hz. Future 250 GHz experiments require beam parameters of 10 MeV energy, 3 kA current, 50 ns pulse width and a brightness of 1 × 108 A/(m rad)2 with a 5 kHz prf for 0.5 s. In this paper we discuss the present status of ETA-II parameters and the phased development program necessary to satisfy these future requirements.
Kinematical Conformal Cosmology: Fundamental Parameters from Astrophysical Observations

We continue the presentation of an alternative cosmology based on conformal gravity, following our kinematical approach to the subject introduced in a recent paper. In line with the assumptions of our model, which proposes a closed-form expression for the cosmic scale factor 𝑅 ( 𝑡 ) , we revise the Hubble and deceleration parameters and introduce modified cosmological distances, analyzing in particular the case of the luminosity distance. Our kinematical conformal cosmology is then able to explain the anomalous acceleration of the Pioneer spacecraft, as due to a local region of gravitational blueshift. From the reported data of the Pioneer anomaly, we also compute the current value of our first fundamental parameter, 𝛾 0 = 1 . 9 4 × 1 0 − 2 8 c m − 1 , in line with the original estimate by P. Mannheim of this quantity. Our second fundamental parameter, 𝛿 0 = 3 . 8 3 × 1 0 − 5 , interpreted as the current value of a cosmological time variable, is derived from a detailed fitting of type Ia supernovae “gold-silver” data, producing Hubble plots of the same quality of those obtained by standard cosmology, but without requiring any dark matter or dark energy contribution. If further experiments will confirm the presence of an anomalous frequency blueshift in the outer region of the solar system, as described by our model, kinematical conformal cosmology might become a viable alternative to standard cosmological theories.
Do Teenagers Respond to HIV Risk Information? Evidence from a Field Experiment in Kenya

This brief summarizes the teenagers respond to HIV risk information? Evidence from a field experiment in Kenya. The training occurred over four months from February 2003 to May 2003. The relative risk campaign was phased in from July 2004 to October 2004. Providing information on the relative risk of HIV infection by partner's age led to a 28 percent decrease in teen pregnancy, an objective proxy for the incidence of unprotected sex. Self-reported sexual behavior data suggests substitution away from older (riskier) partners and toward same-age partners. In contrast, the official abstinence-only HIV curriculum had no impact on teen pregnancy. These results suggest that teenagers are responsive to risk information, but their sexual behavior is more elastic on the intensive than on the extensive margin.
Resource sharing and coevolution in evolving cellular automata

Coevolution, between a population of candidate solutions and a population of test cases, has received increasing attention as a promising biologically inspired method for improving the performance of evolutionary computation techniques. However, the results of studies of coevolution have been mixed. One of the seemingly more impressive results to date was the improvement via coevolution demonstrated by Juille and Pollack (1998) on evolving cellular automata to perform a classification task. Their study, however, like most other studies on coevolution, did not investigate the mechanisms giving rise to the observed improvements. In this paper, we probe more deeply into the reasons for these observed improvements and present empirical evidence that, in contrast to what was claimed by Juille and Pollack, much of the improvement seen was due to their "resource sharing" technique rather than to coevolution. We also present empirical evidence that resource sharing works, at least in part, by preserving diversity in the population.
Powder Processing Science and Technology for Increased Reliability

Issues concerning powder consolidation methods compatible with the colloidal approach and issues associated with other powder processing steps, viz., densification and microstructural control, are presented with regard to research directions leading to more reliable ceramics.
Reaction of neopentane with hydrogen over Pd/SiO2

Recently the authors suggested that the reaction of neopentane with hydrogen would be a good probe for the activity characterization of supported Pd catalysts; in particular, the selectivity toward isomerization appears to be a good measure of the interaction of Pd with the support. For example, with Pd/SiO{sub 2} and Pd/TiO{sub 2} reduced at higher temperatures, there is a considerable growth in isomerization selectivity compared to lower temperature-reduced materials. However, it is important to distinguish between chemical and topographical effects in such modifications, and the authors have investigated both. Some earlier work with neopentane/H{sub 2} indicated that (111)-oriented Pd films are very selective toward isomerization ({approximately}70% at T {approximately} 275 C), but lose this selectivity after various pretreatments that lead to formation of a defect structure. However, Pd powders do not exhibit this selectivity even after high-temperature reduction. In view of this, and the results presented here, it seems clear that the prior work on Pd(111) was affected by extraneous surface effects, possibly the formation of Pd silicides after annealing in H{sub 2} at 500 C. Still, there appears to be a large effect of morphology of Pd on the neopentane reaction, but little is known about the effect ofmore » particle size, particularly with respect to supported catalysts. In the present study the authors use a well-characterized series of Pd/SiO{sub 2} to look further at this question in a situation where metal-support interactions should be absent.« less
Distinguishing division algebras by finite splitting fields

This paper is concerned with the problem of determining the number of division algebras which share the same collection of finite splitting fields. As a corollary we are able to determine when two central division algebras may be distinguished by their finite splitting fields over certain fields.
Rating in Microfinance: Cross-Country Evidence

This paper studies whether microfinance rating agencies are able to impose market discipline by rating Microfinance Institutions’ performance. Results indicate that not all rating agencies are equal as only one rater imposed market discipline by promoting better sustainability and offered credible rating reports that allowed MFIs to borrow more money.
Discovering Likely Invariants of Distributed Transaction Systems for Autonomic System Management

Large amount of monitoring data can be collected from distributed systems as the observables to analyze system behaviors. However, without reasonable models to characterize systems, we can hardly interpret such monitoring data effectively for system management. In this paper, a new concept named flow intensity is introduced to measure the intensity with which internal monitoring data reacts to the volume of user requests in distributed transaction systems. We propose a novel approach to automatically model and search relationships between the flow intensities measured at various points across the system. If the modeled relationships hold all the time, they are regarded as invariants of the underlying system. Experimental results from a real system demonstrate that such invariants widely exist in distributed transaction systems. Further we discuss how such invariants can be used to characterize complex systems and support autonomic system management.
Scale estimation for turbulent flows in porous media

The results of an experimental study to determine the smallest, dissipative scales of the turbulent flow in a randomly packed porous bed are presented and discussed. Particle Image Velocimetry was used to obtain time dependent two-dimensional velocity fields within the bed, which were then used to obtain turbulent statistical measures within the flow field. Results are presented for representative pores for a range of pore Reynolds numbers, Repore, from 839 to 3964, which include integral length and velocity scales and estimates of the Kolmogorov scales of length, velocity and time. The results show an asymptotic region at sufficiently high Repore, on the order of 2800, where scaling is normalized using the bed pore scales. It is also shown that the turbulent Reynolds number for this flow in the asymptotic limit is on the order of 0.07Repore, for the range of pores studied.
Open system protocols for aviation data link applications

Discusses the advantages to the aviation data link community of employing "open system" design in the data link communications system architecture. The two candidate open system protocols, ATN and Internet, have been outlined and compared against a set of criteria for aviation data link applications. It is argued that the Internet protocols should be selected as the communications framework for aviation data link. A design for inter-operating the Internet protocols over the existing VDL-2 subnetwork has been proposed and outlined. It appears to provide all the benefits of the Internet open system approach while simultaneously supporting the ATN (if desired). Future work in this area clearly involves finishing the development and prototyping of the VDL-2/LP DLP design. Internet DLP designs for other aviation data link subnetworks need to be developed.
On the Mass-to-Light Ratio of Large-Scale Structure

We examine the dependence of the mass-to-light (M/L) ratio of large-scale structure on cosmological parameters, in models that are constrained to match observations of the projected galaxy correlation function wp(rp) and the galaxy luminosity function. For a sequence of cosmological models with a fixed, observationally motivated power spectrum shape and increasing normalization σ8, we find parameters of the galaxy halo occupation distribution (HOD) that reproduce wp(rp) measurements as a function of luminosity from the Sloan Digital Sky Survey (SDSS). From these HOD models we calculate the r-band conditional luminosity function Φ(L|Mh), and from this the mean M/L ratio as a function of halo mass Mh. We also use Φ(L|Mh) to populate halos of N-body simulations with galaxies and thereby compute M/L in a range of large-scale environments, including cluster infall regions. For all cosmological models, the M/L ratio in high-mass halos or high-density regions is approximately independent of halo mass or smoothing scale. However, the "plateau" value of M/L depends on σ8 in addition to the obvious proportionality with the matter density parameter Ωm, and it represents the universal value M/L = Ωmρcrit/ρlum only for models in which the galaxy correlation function is approximately unbiased, i.e., with σ8 ≈ σ8g. Our results for cluster mass halos follow the trend (M/L)cl = 577(Ωm/0.3)(σ8/0.9)1.7 h M☉/L☉. Combined with the mean M/L ratio for CNOC galaxy clusters, this relation implies (σ8/0.9)(Ωm/0.3)0.6 = 0.75 ± 0.06. M/L estimates for SDSS clusters and the virial regions of clusters in the CAIRNS survey imply a similar value of σ8Ω, while the CAIRNS estimates for cluster infall regions imply a lower value. These results are inconsistent with parameter values Ωm ≈ 0.3, σ8 ≈ 0.9 favored by recent joint analyses of cosmic microwave background measurements and other large-scale structure data, although they agree with values inferred from the van den Bosch et al. analysis of the 2dF Galaxy Redshift Survey. We discuss possible resolutions of this discrepancy, none of which seems entirely satisfactory. In appendices we present an improved formula for halo bias factors calibrated on our 3603 N-body simulations and an improved analytic technique for calculating the galaxy correlation function from a given cosmological model and HOD.
Characterization of Steady Blowing for Flow Control in a Hump Diffuser

A study has been performed to characterize the effects of steady boundary-layer injection on the separated flow of a hump diffuser. Results of parametrically varying discrete hole blowing characteristics have identified two separate regimes where the injection momentum coefficient and velocity ratio, respectively, are the primary scaling parameters for pressure recovery. Both discrete hole and slot injection have been investigated for varying degrees of adverse pressure gradient in the streamwise direction, indicating optimal discrete hole injection to be more efficient than slot injection in terms of necessary injection momentum coefficient to achieve maximum levels of increased pressure recovery. The effects of discrete injection parameters such as hole diameter, hole spacing, and streamwise injection (yaw) angle have been studied. Angled injection (45-deg yaw) has been shown to be most effective in removing separated flow and increasing the pressure recovery. The angled injection enhances shear layer mixing through large-scale corotating vortical motion induced by the yawed jet-main flow interaction. A computational fluid dynamics/data comparison study has been performed on the results of the discrete injection tests, capturing overall data trends and representing the net effect of streamwise and angled injection on pressure recovery in the hump diffuser.
A model of the perception of facial expressions of emotion by humans: research overview and perspectives

In cognitive science and neuroscience, there have been two leading models describing how humans perceive and classify facial expressions of emotion--the continuous and the categorical model. The continuous model defines each facial expression of emotion as a feature vector in a face space. This model explains, for example, how expressions of emotion can be seen at different intensities. In contrast, the categorical model consists of C classifiers, each tuned to a specific emotion category. This model explains, among other findings, why the images in a morphing sequence between a happy and a surprise face are perceived as either happy or surprise but not something in between. While the continuous model has a more difficult time justifying this latter finding, the categorical model is not as good when it comes to explaining how expressions are recognized at different intensities or modes. Most importantly, both models have problems explaining how one can recognize combinations of emotion categories such as happily surprised versus angrily surprised versus surprise. To resolve these issues, in the past several years, we have worked on a revised model that justifies the results reported in the cognitive science and neuroscience literature. This model consists of C distinct continuous spaces. Multiple (compound) emotion categories can be recognized by linearly combining these C face spaces. The dimensions of these spaces are shown to be mostly configural. According to this model, the major task for the classification of facial expressions of emotion is precise, detailed detection of facial landmarks rather than recognition. We provide an overview of the literature justifying the model, show how the resulting model can be employed to build algorithms for the recognition of facial expression of emotion, and propose research directions in machine learning and computer vision researchers to keep pushing the state of the art in these areas. We also discuss how the model can aid in studies of human perception, social interactions and disorders.
LINEAR POLARIZATION IN GAMMA-RAY BURSTS: THE CASE FOR AN ORDERED MAGNETIC FIELD

Linear polarization at the level of ~1%-3% has by now been measured in several gamma-ray burst afterglows. Whereas the degree of polarization, P, was found to vary in some sources, the position angle, θp, was roughly constant in all cases. Until now, the polarization has been commonly attributed to synchrotron radiation from a jet with a tangled magnetic field that is viewed somewhat off-axis. However, this model predicts either a peak in P or a 90° change in θp around the "jet break" time in the light curve, for which there has so far been no observational confirmation. We propose an alternative interpretation, wherein the polarization is attributed, at least in part, to a large-scale, ordered magnetic field in the ambient medium. The ordered component may dominate the polarization even if the total emissivity is dominated by a tangled field generated by postshock turbulence. In this picture, θp is roughly constant because of the uniformity of the field, whereas P varies as a result of changes in the ratio of the ordered-to-random mean-squared field amplitudes. We point out that variable afterglow light curves should be accompanied by a variable polarization. The radiation from the original ejecta, which includes the prompt γ-ray emission and the emission from the reverse shock (the "optical flash" and "radio flare"), could potentially exhibit a high degree of polarization (up to ~60%) induced by an ordered transverse magnetic field advected from the central source.
Protocolized and Target-based Sedation and Analgesia in the ICU

Important goals in the management of patients who are critically ill include prevention and relief of suffering and distress and the provision of safe and effective care that leads to optimal outcomes. Administration of sedatives and analgesics is a cornerstone for optimizing patient comfort and minimizing distress, particularly for patients on mechanical ventilation, yet it may lead to unintended consequences including adverse drug effects and delayed recovery from critical illness. 1–5 As with all aspects of medical management, thoughtful patient-focused care should be based on sound principles and evidence from relevant research. Although individual care for patients, led by experienced clinicians, is central to effective sedation and analgesia management, this aspect of care is particularly well-suited to a structured approach because of the ever-changing patient status that requires repeated evaluation and medication titration at the bedside and the multidisciplinary nature of the care. 6 Within the context of a comprehensive review of the many aspects of sedation and analgesia in patients who are critically ill in this issue of the Clinics, this article will focus on structured approaches to sedation management with emphasis on protocolized, target-based care. The use of protocolized care, with structured approaches that prioritize avoiding the accumulation of drugs and metabolites that could lead to a slower recovery, is supported by a rapidly expanding body of evidence. 1,7 Such strategies embrace the notion of administering the right drug(s) in the right dose to the right patient at the right time for the right reasons. Decision making by clinicians at the bedside—primarily nurses—regarding sedation and analgesia is complex,
Counting the World's Poor: Problems and Possible Solutions

As recent discussions have made clear, the apparent lack of poverty reduction in the face of historically high rates of economic growth—both in the world as a whole and in specific countries (most notably India)—provides fuel for the argument that economic growth does little to reduce poverty. How confident can we be that the data actually support these inferences? At the international level, the regular revision of purchasing power parity exchange rates plays havoc with the poverty estimates, changing them in ways that have little or nothing to do with the actual experience of the poor. At the domestic level, the problems in measuring poverty are important not only for the world count but also for tracking income poverty within individual countries. Yet, in many countries, there are large and growing discrepancies between the survey data—the source of poverty counts—and the national accounts—the source of the measure of economic growth. Thus economic growth, as measured, has at best a weak relationship with poverty, as measured. The World Bank prepares and publishes estimates of the number of poor people in the world. Although these numbers should be taken with a pinch of salt, they are arguably important. In an institution where the reduction of poverty is the paramount objective, some overall yardstick of progress (or the lack of it) is required. The numbers are frequently quoted by politicians and by leaders of international organizations, including the World Bank itself, who believe the numbers are effective for advocacy. Indeed, there is a long history of studies of poverty mobilizing support among the nonpoor for antipoverty policies. So it is important to know whether the world and national poverty counts are sound enough to support these uses. As recent discussions have made clear, the apparent lack of poverty reduction in the face of historically high rates of economic growth—both in the world as a whole and in specific countries (most notably India)—is providing fuel for the argument that economic growth does little to reduce poverty. How confident can we be that the data actually support these inferences? Are the changes in the poverty counts sufficiently well measured to support conclusions about growth and poverty reduction? Should
Linear-Algebraic List Decoding of Folded Reed-Solomon Codes

Folded Reed-Solomon codes are an explicit family of codes that achieve the optimal trade-off between rate and error-correction capability: specifically, for any " > 0, the author and Rudra (2006, 08) presented an nO(1=") time algorithm to list decode appropriate folded RS codes of rate R from a fraction 1--R--e" of errors. The algorithm is based on multivariate polynomial interpolation and root-finding over extension fields. It was noted by Vadhan that interpolating a linear polynomial suffices if one settles for a smaller decoding radius (but still enough for a statement of the above form). Here we give a simple linear-algebra based analysis of this variant that eliminates the need for the computationally expensive rootfinding step over extension fields (and indeed any mention of extension fields). The entire list decoding algorithm is linearalgebraic, solving one linear system for the interpolation step, and another linear system to find a small subspace of candidate solutions. Except for the step of pruning this subspace, the algorithm can be implemented to run in quadratic time. The theoretical drawback of folded RS codes are that both the decoding complexity and proven worst-case list-size bound are n (1="). By combining the above idea with a pseudorandom subset of all polynomials as messages, we get a Monte Carlo construction achieving a list size bound of O(1="2) which is quite close to the existential O(1=") bound (however, the decoding complexity remains n (1=")).Our work highlights that constructing an explicit subspaceevasive subset that has small intersection with low-dimensional subspaces -- an interesting problem in pseudorandomness in its own right -- could lead to explicit codes with better listdecoding guarantees.
A new approach to program testing

The current approach for testing a program is, in principle, quite primitive. Some small sample of the data that a program is expected to handle is presented to the program. If the program produces correct results for the sample, it is assumed to be correct. Much current work focuses on the question of how to choose this sample. We propose that a program can be more effectively tested by executing it "symbolically." Instead of supplying specific constants as input values to a program being tested, one supplies symbols. The normal computational definitions for the basic operations performed by a program can be expanded to accept symbolic inputs and produce symbolic formulae as output. If the flow of control in the program is completely independent of its input parameters, then all output values can be symbolically computed as formulae over the symbolic inputs and examined for correctness. When the control flow of the program is input dependent, a case analysis can be performed producing output formulae for each class of inputs determined by the control flow dependencies. Using these ideas, we have designed and implemented an interactive debugging/testing system called EFFIGY.
Global Supply Chains and Wage Inequality

A salient feature of globalization in recent decades is the emergence of “global supply chains” in which different countries specialize in different stages of a sequential production process. In Costinot, Vogel, and Wang (2011), CVW hereafter, we have developed a simple theory of trade with sequential production to shed light on how global supply chains affect the interdependence of nations. The goal of this paper is to develop a multifactor extension of CVW to explore how the emergence of global supply chains may affect wage inequality within countries. We start from the same basic environment as in Costinot and Vogel (2010), CV hereafter. As in CV, we consider a world economy with two countries, North and South, each populated by a continuum of workers with different skills. Both countries have access to the same technology for producing a unique final good, but North is skill abundant relative to South. Crucially, as in CVW, production of the final good requires a continuum of stages to be performed sequentially. At each stage, producing new intermediate goods requires workers and intermediate goods produced in the previous stage. The more skilled
A new multi-ramp driver model with RLC interconnect load

As the feature size is scaled down to 90nm and below, fundamental modelling changes, such as the nonlinearity and higher frequencies of signals, require driver-load models to take into account propagation delay and slew rates. The conventional single Ceff (one-ramp) with lumped RC model is no longer accurate. In this paper we propose a new multi-ramp model with general RLC interconnects as loads. This new model accurately predicts both the 50% delay and the overall output waveform shape with inductance effects.
Optimal transport and Perelman’s reduced volume

We show that a certain entropy-like function is convex, under an optimal transport problem that is adapted to Ricci flow. We use this to reprove the monotonicity of Perelman’s reduced volume.