cssi/SciSciGPT-SciSciNet huggingface dataset:
An overview of solution-based semiconductor nanowires: synthesis and optical studies

This Perspective describes recent progress in the synthesis and optical characterization of high quality solution-based semiconductor nanowires (NWs). The described solution-phase NW syntheses are analogous to conventional vapor–liquid–solid (VLS) growth schemes for 1D materials. However, a primary difference is that low melting catalyst particles are used to induce the asymmetric crystallization of wires at temperatures sustainable by solution chemistry (T < 400 °C). Reactions are conducted in the presence of mild coordinating solvents such as trioctylphosphine oxide, which modulate NW growth kinetics and passivate their surfaces. This approach borrows from concurrent advances in colloidal quantum dot (QD) syntheses. In particular, the appropriate choice of solvent, coordinating ligands, growth conditions and precursors all originate from existing preparations for high quality semiconductor QDs. Subsequent structural characterization of the nanowires reveals their high degree of crystallinity, low ensemble size distributions and intrawire uniformity. Variations of these syntheses yield branched CdSe, CdTe and PbSe NWs with characteristic tripod, v-shape, y-shape, t-shape and “higher order” morphologies. A “geminate” NW nucleation mechanism is used to explain this phenomenon. The proposed branching model is also predictive and can be tested by additional nanowire syntheses that we or others conduct. Corresponding optical properties of both straight and branched wires are described, including measurements of their frequency-dependent absorption cross sections. Preliminary ensemble experiments focus on transient differential absorption measurements to study relevant carrier relaxation pathways and timescales over which these processes occur. Additional studies reveal intrawire optical heterogeneity and fluorescence intermittency at the single NW level.
Testing two-field inflation

We derive accurate semianalytic formulas for the power spectra from two-field inflation assuming an arbitrary potential and arbitrary noncanonical kinetic terms, and we use them both to build phenomenological intuition and to constrain classes of two-field models using WMAP data. Using covariant formalism, we first develop a framework for understanding the background field kinematics and introduce a ``slow-turn'' approximation. Next, we find covariant expressions for the evolution of the adiabatic/curvature and entropy/isocurvature modes, and we discuss how the evolution of modes can be inferred mostly from the background kinematics and the geometry of the field manifold. From these expressions, we derive semianalytic formulas for the curvature, isocurvature, and cross spectra, and the standard spectral observables, all to second order in the slow-roll and slow-turn approximations. In tandem, we show how our covariant formalism provides useful intuition into how the general features of the inflationary Lagrangian translate into distinct features in the observable power spectra. In particular, we find that key features of the power spectra can be directly read off from the nature of the roll path, the curve the field vector rolls along with respect to the two-dimensional field manifold. For example, models whose roll path makes a sharp turn around 60 e-foldings before the end of inflation tend to be ruled out because they produce stronger departures from scale invariance than are allowed by the latest CMB observations. Finally, we apply our formalism to confront four classes of two-field models with WMAP data, including doubly quadratic and quartic potentials and nonstandard kinetic terms, showing how whether a model is ruled out or not depends not only on certain features of the inflationary Lagrangian, but also on the initial conditions. Ultimately, for a two-field model to be consistent with observations, we show that it must possess the right balance of certain kinematical and dynamical behaviors, which we reduce to a set of functions that represent the main characteristics of any two-field model of inflation.
Heatbath noise methods in lattice QCD

Abstract In a recent paper, de Forcrand has pointed out that matrix inversions using Gaussian noise need not be iterated to full convergence, but instead may be solved approximately and treated as a heatbath. Gaussian noise however is not optimal for minimizing variance. It shown here how his algorithm may be generalized to a mixture of Gaussian and Z(N) noise, resulting in a smaller effective variance for some operators.
Well Test Analysis for Enhanced Oil Recovery Projects

Recent studies on the transient flow of non-Newtonian fluid in porous media have proposed new well test analysis techniques for non-Newtonian injection wells. This work extends these new techniques to non-Newtonian injection well falloff testing. The practical use of this well test analysis method is demonstrated. The limitations of the techniques also are addressed. Examples of field data are used to demonstrate how this analysis can aid in well tests interpretation and provide data and insight for the design and operation of enhanced oil recovery projects.
On diffeomorphism invariance for lattice theories

Abstract We consider the role of the diffeomorphism constraint in the quantization of lattice formulations of diffeomorphism invariant theories of connections. It has been argued that in working with abstract lattices one automatically takes care of the diffeomorphism constraint in the quantum theory. We use two systems in order to show that imposing the diffeomorphism constraint is imperative to obtain a physically acceptable quantum theory. First, we consider 2 + 1 gravity where an exact lattice formulation is available. Next, general theories of connections for compact gauge groups are treated, where the quantum theories are known - for both the continuum and the lattice - and can be compared.
The Einstein soft X-ray survey of the Pleiades.

The results of a 0.1-4.5-keV X-ray survey of a 2 x 2-deg area centered on the Pleiades open cluster, performed using the imaging proportional counter and high-resolution imager of the Einstein Observatory on four days in 1980-1981, are presented in extensive tables, graphs, maps, histograms, and finding charts and characterized. A total of 61 sources are detected, and 44 of these are identified with cluster members of spectral types B-M. Findings discussed include Lx/Lbol of 10 the -7th for early-type stars; F-star mean Lx like that of F stars in the Hyades and in the field (denying time evolution of Lx); mean G-star Lx = 3.7 x 10 to the 29th erg/sec; G-star activity decay more gradual than 1/sq rt t, with sharp fall for t greater than 1 Gyr; and no evidence for X-ray-emissivity/rotational-velocity correlation in a homogeneous sample of K dwarfs or a sample of K and M stars with established V sin i data.
Mortgage Foreclosures and the Changing Mix of Crime in Micro-neighborhoods

Objectives:The main objectives of the study are to estimate the impact of mortgage foreclosures on the location of criminal activity within a blockface. Drawing on routine activity theory, disorder theory, and social disorganization theory, the study explores potential mechanisms that link foreclosures to crime.Methods:To estimate the relationship between foreclosures and localized crime, we use detailed foreclosure and crime data at the blockface level in Chicago and a difference-in-difference estimation strategy.Results:Overall, mortgage foreclosures increase crime on blockfaces. Foreclosures have a larger impact on crime that occurs inside residences than on crime in the street. The impact of foreclosures on crime location varies by crime type (violent, property, and public order crime).Conclusions:The evidence supports the three main theoretical mechanisms that link foreclosure activity to local crime. The investigation of the relationship by crime location suggests that foreclosures change the relati...
Strongly sufficient sets and the distribution of arithmetic sequences in the 3x+1 graph

Abstract The 3 x + 1 conjecture asserts that the T -orbit of every positive integer contains 1 , where T maps x ↦ x / 2 for x even and x ↦ ( 3 x + 1 ) / 2 for x odd. A set S of positive integers is sufficient if the orbit of each positive integer intersects the orbit of some member of S . Monks (2006) [8] showed that every infinite arithmetic sequence is sufficient. In this paper we further investigate the concept of sufficiency. We construct sufficient sets of arbitrarily low asymptotic density in the natural numbers. We determine the structure of the groups generated by the maps x ↦ x / 2 and x ↦ ( 3 x + 1 ) / 2 modulo b for b relatively prime to 6 , and study the action of these groups on the directed graph associated to the 3 x + 1 dynamical system. From this we obtain information about the distribution of arithmetic sequences and obtain surprising new results about certain arithmetic sequences. For example, we show that the forward T -orbit of every positive integer contains an element congruent to 2 mod 9 , and every non-trivial cycle and divergent orbit contains an element congruent to 20 mod 27 . We generalize these results to find many other sets that are strongly sufficient in this way. Finally, we show that the 3 x + 1 digraph exhibits a surprising and beautiful self-duality modulo 2 n for any n , and prove that it does not have this property for any other modulus. We then use deeper previous results to construct additional families of nontrivial strongly sufficient sets by showing that for any k n , one can “fold” the digraph modulo 2 n onto the digraph modulo 2 k in a natural way.
Una nueva especie de rana de cristal del género Hyalinobatrachium (Anura: Centrolenidae) del Delta del Río Orinoco, Venezuela

Se describe una nueva especie de Hyalinobatrachium del grupo fleischmanni, H. mondolfii, de las planicies inundables del delta del rio Orinoco, Venezuela. Hyalinobatrachium mondolfii se distingue del resto de las especies del grupo por la siguiente combinacion de caracteres: peritoneo parietal translucido, pericardio y peritoneos visceral y hepatico blancos, coloracion dorsal en vida verde claro con diminutos puntos amarillos y en preservativo crema uniforme con diminutos melanoforos oscuros (visibles solo bajo magnificacion, huesos blancos en vida, palmeadura de manos y pies extensa, cabeza redondeada en vista dorsal e inclinada en vista lateral, piel dorsal granular y un canto con frecuencia fundamental superior a los 5 000 Hz.
Design, synthesis, and photophysical characterization of novel pentacyclic red shifted azine dyes

As part of our continuing efforts to develop second generation photodynamic therapeutic agents [1], we synthesized three pentacyclic azine dyes that were designed with the aid of MNDO calculations to absorb visible light having wavelengths longer than 600 nm. Photophysical measurements for the azine dyes 1,4,8,11-tetraethyl-1,2,3,4,8,9,10,11,13-nonahydrodipyrazino[2,3-b:2′, 3′-i] phenazinium acetate, 13, 1,4,8,11-tetraethyl-2,3,4,8,9,10,11,12,13-octahydro-13-methyldipyrazino[2,3-b:2,3′-i]phenazinium iodide, 14, and l,4,8,11,13-pentaethyl-2,3,4,8,9,10,11,12,13-octahydrodipyrazino[2,3-b:2′,3′-i]phenazinium iodide, 15, are highlighted by a 35 nm red shift in their absorption spectra and a 5–7 fold increase in their singlet oxygen quantum yield relative to tricyclic model compounds 3,7-bis(diethylamino)phenazinium chloride, 20, and 3,7-bis(diethylamino)-5-ethyl-phenazinium iodide, 21, which were also synthesized for this study. Incorporation of rigid peripheral tetrahydropyrazino ring systems in the pentacyclic azines 13, 14, and 15 are responsible for the improved fluorescence and singlet oxygen quantum yields relative to the tricyclic azines 20 and 21.
Poverty and Program Participation among Immigrant Children.

Researchers have long known that poverty in childhood is linked with a range of negative adult socioeconomic outcomes, from lower educational achievement and behavioral problems to lower earnings in the labor market. But few researchers have explored whether exposure to a disadvantaged background affects immigrant children and native children differently. George Borjas uses Current Population Survey (CPS) data on two specific indicators of poverty-the poverty rate and the rate of participation in public assistance programs-to begin answering that question. He finds that immigrant children have significantly higher rates both of poverty and of program participation than do native children. Nearly half of immigrant children are being raised in households that receive some type of public assistance, compared with roughly one-third of native children. Although the shares of immigrant and native children living in poverty are lower, the rate for immigrant children is nonetheless about 15 percentage points higher than that for native children-about the same as the gap in public assistance. Poverty and program participation rates among different groups of immigrant children also vary widely, depending in part on place of birth (foreign- or U.S.-born), parents (immigrant or native), and national origin. According to the CPS data, these native-immigrant differences persist into young adulthood. In particular, the program participation and poverty status of immigrant children is strongly correlated with their program participation and poverty status when they become young adults. But it is not possible, says Borjas, to tell whether the link results from a set of permanent factors associated with specific individuals or groups that tends to lead to "good" or "bad" outcomes systematically over time or from exposure during childhood to adverse socioeconomic outcomes, such as poverty or welfare dependency. Future research must explore the causal impact of childhood poverty on immigrant adult outcomes and why it might differ between immigrant and native families. Developing successful policies to address problems caused by the intergenerational breeding of poverty and program participation in the immigrant population depends on understanding this causal mechanism.
A Probabilistic-Based Design Model for Achieving Flexibility in Design

In this paper we propose the use of a probabilistic-based design model as a basis for providing the flexibility in a design process that allows designs to be readily adapted to changing conditions. Our proposed approach can be used to develop a range of solutions that meet a ranged set of design requirements. Meanwhile, designers are allowed to specify the varying degree of desirability of a ranged set of design performance based on their preferences. The Design Preference Index (DPI) is introduced as a design metric to measure the goodness of flexible designs. Providing the foundation to our work are the probabilistic representations of design performance, the application of the robust design concept, and the utilization of the compromise Decision Support Problem (DSP) as a multiobjective decision model. A two-bar structural design is used as an example to demonstrate our approach. Our focus in this paper is on introducing the probabilistic-based design model and not on the results of the example problem, per se.
Transmission of liquidity shock to bank credit: Evidence from the deposit insurance reform in Japan

Abstract Finding the causal effects of liquidity shocks on credit supply is complicated by the endogenous relation between loan demand and liquidity position of banks. This paper attempts to overcome this problem by exploiting, as a natural experiment, the exogenous deposit outflow prompted by the removal of a blanket deposit guarantee on time deposits in Japan. We find that during the period of transition from a blanket guarantee to a partial guarantee, weak banks suffered from a large outflow of partially insured time deposits. More importantly, we find that those weak banks were not able to raise a sufficient amount of other types of deposits to make up for the loss of time deposits, which, consequently, forced them to cut back on loan supply. These results are consistent with the theory that the imperfect substitutability of insured deposits and uninsured deposits affects the tightness of banks’ financing constraints and ultimately the supply of bank loans.
Examining influential factors in providers’ chronic pain treatment decisions: a comparison of physicians and medical students

Chronic pain treatment guidelines are unclear and conflicting, which contributes to inconsistent pain care. In order to improve pain care, it is important to understand the various factors that providers rely on to make treatment decisions. The purpose of this study was to examine factors that reportedly influence providers’ chronic pain treatment decisions. A secondary aim was to examine differences across participant training level. Eighty-five participants (35 medical students, 50 physicians) made treatment decisions for 16 computer-simulated patients with chronic pain. Participants then selected from provided lists the information they used and the information they would have used (had it been available) to make their chronic pain treatment decisions for the patient vignettes. Frequency analyses indicated that most participants reported using patients’ pain histories (97.6 %) and pain description (95.3 %) when making treatment decisions, and they would have used information about patients’ previous treatments (97.6 %) and average and current pain ratings (96.5 %) had this information been available. Compared to physicians, medical students endorsed more frequently that they would have used patients’ employment and/or disability status (p < 0.05). A greater proportion of medical students wanted information on patients’ use of illicit drugs and alcohol to make treatment decisions; while a greater proportion of physicians reported using personal experience to inform their decisions. This study found providers use patients’ information and their own experiences and intuition to make chronic pain treatment decisions. Also, participants of different training levels report using different patient and personal factors to guide their treatment decisions. These results highlight the complexity of chronic pain care and suggest a need for more chronic pain education aimed at medical students and practicing providers.
Charge frustration in complex fluids and in electronic systems

Abstract The idea of charge frustration is applied to describe the properties of such diverse physical systems as oil-water-surfactant mixtures and metal-ammonia solutions. The minimalist charge-frustrated model possesses one energy scale and two length scales. For oil-water-surfactant mixtures, these parameters have been determined starting from the microscopic properties of the physical systems under study. Thus, microscopic properties are successfully related to the observed mesoscopic structure.
Approximation Algorithms for Stochastic Inventory Control Models

We consider two classical stochastic inventory control models, the periodic-review stochastic inventory control problem and the stochastic lot-sizing problem. The goal is to coordinate a sequence of orders of a single commodity, aiming to supply stochastic demands over a discrete, finite horizon with minimum expected overall ordering, holding, and backlogging costs. In this paper, we address the important problem of finding computationally efficient and provably good inventory control policies for these models in the presence of correlated, nonstationary (time-dependent), and evolving stochastic demands. This problem arises in many domains and has many practical applications in supply chain management. Our approach is based on a new marginal cost accounting scheme for stochastic inventory control models combined with novel cost-balancing techniques. Specifically, in each period, we balance the expected cost of overordering (i.e., costs incurred by excess inventory) against the expected cost of underordering (i.e., costs incurred by not satisfying demand on time). This leads to what we believe to be the first computationally efficient policies with constant worst-case performance guarantees for a general class of important stochastic inventory control models. That is, there exists a constant C such that, for any instance of the problem, the expected cost of the policy is at most C times the expected cost of an optimal policy. In particular, we provide a worst-case guarantee of two for the periodic-review stochastic inventory control problem and a worst-case guarantee of three for the stochastic lot-sizing problem. Our results are valid for all of the currently known approaches in the literature to model correlation and nonstationarity of demands over time.
Low-frequency Fourier analysis of speech rhythm.

A method for studying speech rhythm is presented, using Fourier analysis of the amplitude envelope of bandpass-filtered speech. Rather than quantifying rhythm with time-domain measurements of interval durations, a frequency-domain representation is used—the rhythm spectrum. This paper describes the method in detail, and discusses approaches to characterizing rhythm with low-frequency spectral information.
Inflation targeting: Should it be modeled as an instrument rule or a targeting rule? ☆

Abstract The paper discusses how current inflation targeting should be modeled, and argues that it is better represented as a commitment to a targeting rule (a rule specifying operational objectives for monetary policy or a condition for the target variables), than as a commitment to a simple instrument rule (like a Taylor rule).
Causes and Consequences of Early-Life Health

We examine the consequences of child health for economic and health outcomes in adulthood, using height as a marker of childhood health. After reviewing previous evidence, we present a conceptual framework that highlights data limitations and methodological problems that complicate the study of this topic. We then present estimates of the associations between height and a range of outcomes—including schooling, employment, earnings, health, and cognitive ability—measured in five data sets from early to late adulthood. These results indicate that, on average, taller individuals attain higher levels of education. Height is also positively associated with better economic, health, and cognitive outcomes. These associations are only partially explained by the higher average educational attainment of taller individuals. We then use data from the National Longitudinal Survey of Youth 1979 Children and Young Adults survey to document the associations between health, cognitive development, and growth in childhood. Even among children with the same mother, taller siblings score better on cognitive tests and progress through school more quickly. Part of the differences found between siblings arises from differences in their birth weights and lengths attributable to mother’s behaviors while pregnant. Taken together, these results support the hypothesis that childhood health influences health and economic status throughout adulthood.
QBETS: queue bounds estimation from time series

Most space-sharing parallel computers presently operated by high-performance computing centers use batch-queuing systems to manage processor allocation. Because these machines are typically "space-shared," each job must wait in a queue until sufficient processor resources become available to service it. In production computing settings, the queuing delay (experienced by users as the time between when the job is submitted and when it begins execution) is highly variable. Users often find this variability a drag on productivity as it makes planning difficult and intellectual continuity hard to maintain. In this work, we introduce an on-line system for predicting batch-queue delay and show that it generates correct and accurate bounds for queuing delay for batch jobs from 11 machines over a 9-year period. Our system comprises 4 novel and interacting components: a predictor based on nonparametric inference; an automated change-point detector; machine-learned, model-based clustering of jobs having similar characteristics; and an automatic downtime detector to identify systemic failures that affect job queuing delay. We compare the correctness and accuracy of our system against various previously used prediction techniques and show that our new method outperforms them for all machines we have available for study.
Reactivity and Intersystem Crossing of Singlet Methylene in Solution

Evidence is reported which demonstrates that singlet methylene, produced from the photolysis of diazomethane or diazirine, undergoes intersystem crossing to form triplet methylene in perfluorohexane solvent. The results of triplet sensitized photolysis and of direct photolysis experiments with dilute concentrations of substrate (cis- and trans-2-pentene and chloroform) appear to be essentially identical. Stern-Volmer analyses of the competition kinetics between acetonitrile and 2-pentenes or chloroform for singlet methylene are consistent with the near diffusion controlled reactivity of singlet methylene. With the assumption of diffusion-controlled reactions for singlet methylene, plots of the quantum yield for singlet vs. triplet reaction for methylene allow the first estimate (58 X lo8 s-l) of the rate of intersystem crossing of singlet methylene in the condensed phase. This value is considerably smaller than the value that is extrapolated to the solution phase from results in the gas phase. The possible reasons for this difference are discussed. Methylene (CH,), the parent of the carbene family, has at- tracted the attention of organic chemists,' theorists,, spectro- scopist~,~ and chemical physicist^.".^ Almost all of the quantitative information concerning this species is derived from gas-phase investigations,6 from which it has been concluded that CH2 is a ground state triplet (3CH2) and that a low-lying singlet state ('CH,) exists at about 9 kcal/mo17 above the ground state (Figure 1). Methylene possesses one carbon atom, two hydrogen atoms, and two nonbonding electrons. The two nonbonding electrons occupy the u and T orbitals with their spins parallel for the more linear VH, (6 = 136O), while they occupy the u orbital paired spins for the lowest energy singlet methylene (0 = 102O) (Figure 1). Both states have been observed spectroscopically in the gas phase,3 and from kinetic investigation^^.^ it has been concluded that 'CH2 is quenched by all additives, even inert gases, with high efficiency. Indeed, extrapolation of the gas-phase quenching data to the solution phase leads to the expectation that the lifetime of ICH2 will be of the order of picoseconds in the condensed phase. For example, 'CH, is quenched by He in the gas phase4 with a rate constant of ca. 4 X cm3 molecule-' s-', which translates into a bimolecular rate constant of ca. 2 X lo9 M-l s-I. For an organic solvent concentration of 5 M, the rate of quenching for a completely inert solvent (such as helium!) would be 1 X 1O'O s-I, implying a lifetime of the order of 50 ps or less for 'CH2 in solution. This expectation is based on the assumption that the rate of the 'CH2 deactivation is a linear function of pressure even at high pressure (or in the solution phase). Since quenching must involve either reaction or intersystem crossing to 3CH2, one is led
Elucidating the structure of the magnesium aluminum chloride complex electrolyte for magnesium-ion batteries

Non-aqueous Mg-ion batteries offer a promising way to overcome safety, costs, and energy density limitations of state-of-the-art Li-ion battery technology. We present a rigorous analysis of the magnesium aluminum chloride complex (MACC) in tetrahydrofuran (THF), one of the few electrolytes that can reversibly plate and strip Mg. We use ab initio calculations and classical molecular dynamics simulations to interrogate the MACC electrolyte composition with the goal of addressing two urgent questions that have puzzled battery researchers: (i) the functional species of the electrolyte, and (ii) the complex equilibria regulating the MACC speciation after prolonged electrochemical cycling, a process termed as conditioning, and after prolonged inactivity, a process called aging. A general computational strategy to untangle the complex structure of electrolytes, ionic liquids and other liquid media is presented. The analysis of formation energies and grand-potential phase diagrams of Mg–Al–Cl–THF suggests that the MACC electrolyte bears a simple chemical structure with few simple constituents, namely the electro-active species MgCl+ and AlCl4− in equilibrium with MgCl2 and AlCl3. Knowledge of the stable species of the MACC electrolyte allows us to determine the most important equilibria occurring during electrochemical cycling. We observe that Al deposition is always preferred to Mg deposition, explaining why freshly synthesized MACC cannot operate and needs to undergo preparatory conditioning. Similarly, we suggest that aluminum displacement and depletion from the solution upon electrolyte resting (along with continuous MgCl2 regeneration) represents one of the causes of electrolyte aging. Finally, we compute the NMR shifts from shielding tensors of selected molecules and ions providing fingerprints to guide future experimental investigations.
AGOA and Apparel: Who Captures the Tariff Rent in the Presence of Preferential Market Access?

HE African Growth and Opportunity Act (AGOA) was signed by PresidentClinton in May 2000 and quickly became one of the most high-proﬁleSpecial and Differential Treatment (SDT) programmes implemented. AGOAintends to encourage ‘higher levels of trade and direct investment in support ofpositive economic and political developments’ throughout sub-Saharan Africa(US Congress, 2000). Thirty-six countries were designated to be eligible for theAGOA preferences for 2003.The main feature of AGOA, like other SDT programmes such as the UnitedStates version of the Generalised System of Preferences (GSP), is the duty-freeaccess granted to certain products. However, AGOA goes beyond the standardGSP provisions and includes a wide range of textiles and apparel in the list ofproducts to receive preferential market access. The trade data indicate that asmall group of apparel exporters have been the main beneﬁciaries of AGOApreferences so far and there has not been signiﬁcant change in the exports of anyother product from the eligible countries.In this paper, we analyse the impact of AGOA’s preferences on prices re-ceived by apparel exporters. In a perfectly competitive market (with homogeneousgoods), exporters who enjoy duty-free access should beneﬁt from a price increase
An Empirical Investigation of System Changes to Frame Links between Design Decisions and Ilities

Maintaining system performance in the presence of uncertainties in design and operating environments is both challenging and increasingly essential as system lifetimes grow longer. In response to perturbations brought on by these uncertainties, such as disturbances, context shifts, and shifting stakeholder needs, systems can continue to deliver value by being either robust or changeable. These lifecycle properties, sometimes called “ilities”, have been proposed as means to achieve system value sustainment in spite of changes in contexts or needs. Intentionally designing for these lifecycle properties is an active area of research, and no consensus has formed regarding how these and other “ilities” might trade off. This paper describes ongoing research that investigates empirical examples of system changes in order to characterize these changes and to develop a categorization scheme for framing and clarifying design approaches for proactively creating ilities in a system. Example categories from the data for system changes include: the perturbation trigger for the change, the type of agent executing the system change, and the valid lifecycle phase for execution. In providing a structured means to identify system change characteristics, this paper informs future research by framing possible relationships between ilities and design choices that enable them.
Pinterest Board Recommendation for Twitter Users

Pinboard on Pinterest is an emerging media to engage online social media users, on which users post online images for specific topics. Regardless of its significance, there is little previous work specifically to facilitate information discovery based on pinboards. This paper proposes a novel pinboard recommendation system for Twitter users. In order to associate contents from the two social media platforms, we propose to use MultiLabel classification to map Twitter user followees to pinboard topics and visual diversification to recommend pinboards given user interested topics. A preliminary experiment on a dataset with 2000 users validated our proposed system.
Isotope incorporation via organoboranes

Organoboranes can be used as precursors to a wide variety of functionally substituted, isotopically labeled compounds. Straightforward boron-based methods for incorporating short-lived and stable isotopes of carbon, nitrogen, oxygen, and the halogens have been developed over a period of 20 years. Application of these methods to biology, agriculture, and medicine has been slowed by the limited availability of boronated precursors containing functional groups appropriate to those fields. The situation has changed markedly with the advent of metal catalyzed boron-based reactions, which now produce a variety of important boronated materials readily available in the laboratory and from commercial sources. This is especially important in the medical and pharmaceutical communities where short-lived isotopes of carbon, nitrogen, and the halogens are demonstrating great value in positron and single photon emission tomographic procedures. Copyright © 2007 John Wiley & Sons, Ltd.
Random Projections for Support Vector Machines

Let X be a data matrix of rank , representing n points in d-dimensional space. The linear support vector machine constructs a hyperplane separator that maximizes the 1norm soft margin. We develop a new oblivious dimension reduction technique which is precomputed and can be applied to any input matrix X. We prove that, with high probability, the margin and minimum enclosing ball in the feature space are preserved to within -relative error, ensuring comparable generalization as in the original space. We present extensive experiments with real and synthetic data to support our theory.
Electromechanical wave propagation in large electric power systems

An electrical power network consisting of generators and transmission lines is treated as a continuum system. The application of the limit of zero generator spacing, with finite rotor inertia and transmission line impedance per unit length, yields a nonlinear partial differential equation in time and two spatial dimensions for the rotor phase angle. The equation is a nonlinear version of the standard second-order wave equation which exhibits an explicit expression for the finite wave phase velocity. The electromechanical wave propagation characteristics, equilibrium solutions, and linear stability are investigated and some potentially important results are presented. Numerical simulations of the usual discrete generator model, based upon the swing equation, are presented and demonstrate the electromechanical wave propagation as having interesting properties. Numerical solutions of the analogous continuum model are compared to the discrete model and are found to be in excellent agreement. A numerical estimate of the wave phase velocity for the U.S. power grid is consistent with observations of the transient wave phenomena during staged fault events. The continuum model enables an array of alternative analytic and simulation methods to be applied to the study of global power system characteristics, such as stability and transient dynamics.
Inequality is bad for the poor

It has been argued that inequality should be of little concern in poor countries on the grounds that (1) absolute poverty in terms of consumption (or income) is the overriding issue in poor countries, and (2) the only thing that really matters to reducing absolute income poverty is the rate of economic growth. The author takes (1) as given but questions (2). He argues that there are a number of ways in which the extent of inequality in a society, and how it evolves over time, influences the extent of poverty today and the prospects for rapid poverty reduction in the future.
Combined Psychotherapy and Pharmacotherapy for Mood and Anxiety Disorders in Adults: Review and Analysis

Studies suggest a complex relationship between cognitive-behavior therapy (CBT) and pharmacotherapy for the combined treatment of mood disorders and anxiety disorders. Combined treatment for depression may have beneficial effects when applied to patients with chronic depression and in cases to prevent relapse. In bipolar disorder there is evidence for a strong effect of psychosocial treatment on the course of the disorder. In the anxiety disorders, there are some benefits in the short term, but combined treatment may limit the maintenance of treatment gains offered by CBT alone. Combined treatment should not be considered the default treatment for mood and anxiety disorders, with the possible exception of bipolar disorder. Instead, decisions whether combined treatment is worth the added cost and effort should be made in relation to the disorder under treatment, the level of severity or chronicity, and the stage of treatment (e.g., acute vs. relapse prevention).
From Infall to Rotation around Young Stellar Objects: A Transitional Phase with a 2000 AU Radius Contracting Disk?

Evidence for a transitional stage in the formation of a low-mass star is reported, intermediate between the fully embedded and the T Tauri phases. Millimeter aperture synthesis observations in the HCO+ J = 1-0 and 3-2, HCN 1-0, 13CO 1-0, and C18O 1-0 transitions reveal distinctly different velocity fields around two embedded, low-mass young stellar objects. The 0.6 M☉ of material around TMC 1 (IRAS 04381+2517) closely follows inside-out collapse in the presence of a small amount of rotation (~3 km s-1 pc-1), while L1489 IRS (IRAS 04016+2610) is surrounded by a 2000 AU radius, flared disk containing 0.02 M☉. This disk shows Keplerian rotation around a ~0.65 M☉ star and infall at 1.3(r/100 AU)-0.5 km s-1, or, equivalently, sub-Keplerian motions around a central object between 0.65 and 1.4 M☉. Its density is characterized by a radial power law and an exponential vertical scale height. The different relative importance of infall and rotation around these two objects suggests that rotationally supported structures grow from collapsing envelopes over a few times 105 yr to sizes of a few thousand AU, and then decrease over a few times 104 yr to several hundred AU typical for T Tauri disks. In this scenario, L1489 IRS represents a transitional phase between embedded young stellar objects and T Tauri stars with disks. The expected duration of this phase of ~5% of the embedded stage is consistent with the current lack of other known objects like L1489 IRS. Alternative explanations cannot explain L1489 IRS's large disk, such as formation from a cloud core with an unusually large velocity gradient or a binary companion that prevents mass accretion onto small scales. It follows that the transfer and dissipation of angular momentum is key to understanding the formation of disks from infalling envelopes.
A HEDONIC MODEL OF RICE TRAITS: ECONOMIC VALUES FROM FARMERS IN WEST AFRICA

New crop varieties often have been promoted in developing countries based upon superior yield vis-a-vis locally available varieties. This research presents a hedonic model for upland rice by drawing upon the input characteristics and consumer good characteristics model literature. Model specification tests determine that a combination of production and consumption characteristics best explains the willingness to pay for new upland rice varieties. This non-separable household model specification determined that four traits explain the willingness to pay for new rice varieties: plant cycle length, plant height, grain elongation/swelling and tenderness. Yield was not a significant explanatory variable of the willingness to pay for seed. The implications of this model are two-fold. First, varietal development and promotion must include post-harvest characteristics in addition to production traits when determining which varieties to promote for official release. Secondly, nonyield production characteristics such as plant height and cycle length are significant factors in producers� assessments of the value of a new variety. Overall, this paper provides an alternative explanation for limited adoption of modern upland rice varieties in West Africa: varietal evaluation programs have focused too narrowly on yield evaluation and have not promoted varieties with superior non-yield characteristics than locally available varieties.
Cosmological Acceleration through Transition to Constant Scalar Curvature

As shown by Parker and Raval, quantum field theory in curved spacetime gives a possible mechanism for explaining the observed recent acceleration of the universe. This mechanism, which differs in its dynamics from quintessence models, causes the universe to make a transition to an accelerating expansion in which the scalar curvature, R, of spacetime remains constant. This transition occurs despite the fact that we set the renormalized cosmological constant to zero. We show that this model agrees very well with the current observed typeIa supernova (SNe-Ia) data. There are no free parameters in this fit, as the relevant observables are determined independently by means of the current cosmic microwave background radiation (CMBR) data. We also give the predicted curves for number count tests and for the ratio, w(z), of the dark energy pressure to its density, as well as for dw(z)/dz versus w(z). These curves differ significantly from those obtained from a cosmological constant, and will be tested by planned future observations.
The maintenance need for water in parenteral fluid therapy

It is generally agreed that the maintenance requirements for water of individuals is determined by their caloric expenditure. By means of the following formulae, the caloric expenditure of hospitalized patients can be determined from weight alone. For weights ranging from 0 to 10 kg, the caloric expenditure is 100 cal/kg/day; from 10 to 20 kg the caloric expenditure is 1000 cal plus 50 cal/kg for each kilogram of body weight more than 10; over 20 kg the caloric expenditure is 1500 cal plus 20 cal/kg for each kilogram more than 20. Maintenance requirements for water depend upon insensible loss of water and renal loss. An allowance of 50 ml/100 cal/day will replace insensible loss of water, and 66.7 ml/100 cal/day will replace the average renal loss so that the total requirement is 116.7 ml/100 cal/day. As water of oxidation will supply approximately 16.7 ml/100 cal/day, the remaining 100 ml/100 cal/day must be supplied to meet the remaining water losses of patients on parenteral fluid therapy. Possible exceptions to this figure are discussed. Maintenance requirements of sodium, chloride and potassium are 3.0, 2.0 and 2.0 mEq/100 cal/day, respectively.
Has India’s Economic Growth Become More Pro-Poor in the Wake of Economic Reforms

The extent to which India's poor have benefited from the country's economic growth has long been debated. A new series of consumption-based poverty measures spanning 50 years, including a 15-year period after economic reforms began in earnest in the early 1990s, is used to examine that issue. Growth has tended to reduce poverty, including in the post reform period. There is no robust evidence of more or less poverty responsiveness to growth since the reforms began, although there are signs of rising inequality. The impact of growth is higher when using poverty measures that reflects distribution below the poverty line and when using growth rates calculated from household surveys rather than national accounts. The urban-rural pattern of growth matters for the pace of poverty reduction. However, in marked contrast to the period before the reforms, urban economic growth in the period after the reforms has brought significant gains to the rural poor as well as the urban poor.
Conic relaxations for transmission system planning

We apply lift-and-project type relaxations for polynomial optimization problems to AC transmission system planning, and obtain new second-order cone and semidefinite models. The models are compared to linear and nonlinear approaches on a six-bus test system.
Market Entry and Consumer Behavior: An Investigation of a Wal-Mart Supercenter

This paper provides an empirical study of entry by a Wal-Mart supercenter into a local market. Using a unique frequent-shopper database that records transactions for over 10,000 customers, we study the impact of Wal-Mart's entry on consumer purchase behavior. We develop a joint model of interpurchase time and basket size to study the impact of competitor entry on two key household decisions: store visits and in-store expenditures. The model also allows for consumer heterogeneity due to observed and unobserved factors. Results show that the incumbent supermarket lost 17% volume---amounting to a quarter million dollars in monthly revenue---following Wal-Mart's entry. Decomposing the lost sales into components attributed to store visits and in-store expenditures, we find that the majority of these losses were due to fewer store visits with a much smaller impact attributed to basket size. We also find that Wal-Mart lures some of the incumbent's best customers, and that retention of a small number of households can significantly reduce losses at the focal store. Finally, certain observed household characteristics such as distance to store, shopping behavior, and product purchase behavior are found to be useful in profiling the defectors to Wal-Mart. Implications and strategies for supermarket managers to compete with Wal-Mart are discussed.
Symbolic, neural, and Bayesian machine learning models for predicting carcinogenicity of chemical compounds.

Experimental programs have been underway for several years to determine the environmental effects of chemical compounds, mixtures, and the like. Among these programs is the National Toxicology Program (NTP) on rodent carcinogenicity. Because these experiments are costly and time-consuming, the rate at which test articles (i.e., chemicals) can be tested is limited. The ability to predict the outcome of the analysis at various points in the process would facilitate informed decisions about the allocation of testing resources. To assist human experts in organizing an empirical testing regime, and to try to shed light on mechanisms of toxicity, we constructed toxicity models using various machine learning and data mining methods, both existing and those of our own devising. These models took the form of decision trees, rule sets, neural networks, rules extracted from trained neural networks, and Bayesian classifiers. As a training set, we used recent results from rodent carcinogenicity bioassays conducted by the NTP on 226 test articles. We performed 10-way cross-validation on each of our models to approximate their expected error rates on unseen data. The data set consists of physical-chemical parameters of test articles, alerting chemical substructures, salmonella mutagenicity assay results, subchronic histopathology data, and information on route, strain, and sex/species for 744 individual experiments. These results contribute to the ongoing process of evaluating and interpreting the data collected from chemical toxicity studies.