cssi/SciSciGPT-SciSciNet huggingface dataset:
On fundamental tradeoffs between delay bounds and computational complexity in packet scheduling algorithms

We clarify, extend, and solve a long-standing open problem concerning the computational complexity for packet scheduling algorithms to achieve tight end-to-end delay bounds. We first focus on the difference between the time a packet finishes service in a scheduling algorithm and its virtual finish time under a GPS (General Processor Sharing) scheduler, called GPS-relative delay. We prove that, under a slightly restrictive but reasonable computational model, the lower bound computational complexity of any scheduling algorithm that guarantees O(1) GPS-relative delay bound is /spl Omega/(logn). We also discover that, surprisingly, the complexity lower bound remains the same even if the delay bound is relaxed to O(n/sup a/) for 0<a<1. This implies that the delay-complexity tradeoff curve is flat in the "interval" [O(1),O(n)). We later conditionally extend both complexity results (for O(1) or O(n/sup a/) delay) to a much stronger computational model, the linear decision tree. Finally, we show that the same complexity lower bounds are conditionally applicable to guaranteeing tight end-to-end delay bounds, if the delay bounds are provided through the Latency Rate (LR) framework.
Aid Flows and “Dutch Disease” in a General Equilibrium Framework for Pakistan

Abstract The impact of development aid has been mainly studied through one-sector and or partial equilibrium models, such as the two-gap framework, “Dutch disease” models, and fiscal response models. These approaches tend to capture inadequately the general equilibrium effects of aid inflows, resulting from income and relative price responses, as well as from the effects on the financial constraints on investment by public and private sector agents in the economy. This article applies a multisectoral general equilibrium framework with a full specification of financial sector relations to Pakistan, overcoming the indicated shortcomings. The model tries to capture the Pakistan economy characterized by commodity and financial market imperfections and structural differences in savings and investment behavior of institutional agents. Model simulations suggest aid inflows tend to generate fairly strong Dutch disease effects in the case of Pakistan. However, more use of aid inflows to alleviate financing constraints on investment of household firms, which are mainly active in traded goods production, could mitigate the Dutch disease effects, whereas nominal exchange rate adjustment appears counterproductive. Comparative country analysis applying similar CGE models for Mexico, the Philippines, and Thailand indicates that the findings for Pakistan are not easily generalizable and depend strongly on the existing economic structure, investment and savings behavior of institutional agents, and the allocation additional capital inflows among public and private sector agents
Wind Tunnel Experiments Relating to Supersonic and Hypersonic Boundary-Layer Transition

Hot-wire anemometry is used to study the origin and growth of "natural" fluctuations in zero pressure-gradient boundary layers for several Mach numbers between 1.6 and 8.5. The importance to transition of certain physical mechanisms is examined through comparison of the fluctuation growth with the sound-forcing and stability theories of Mack. Flow fluctuations of substantial amplitude were observed within the laminar layer ahead of stations where instability amplification is expected to be important. These fluctuations were found to be cross-correlated with the sound field for the higher supersonic speeds, but not for the lower ones. The fluctuation growth rates in the unstable Reynolds number range ahead of the nonlinearity region were in reasonably close agreement with the theory for Mach 4.5; the agreement for Mach 2.2 and 8.5 was qualitative. The second mode of instability was predominant at Mach 8.5.
Discrete Choice with Social Interactions

This paper provides an analysis of aggregate behavioural outcomes when individual utility exhibits social interaction effects. We study generalized logistic models of individual choice which incorporate terms reflecting the desire of individuals to conform to the behaviour of others in an environment of noncooperative decisionmaking. Laws of large numbers are generated in such environments. Multiplicity of equilibria in these models, which are equivalent to the existence of multiple self-consistent means for average choice behaviour, will exist when the social interactions exceed a particular threshold. Local stability of these multiple equilibria is also studied. The properties of the noncooperative economy are contrasted with the properties of an economy in which a social planner determines the set of individual choices. Finally, a likelihood function based on the theoretical model is given and conditions for the econometric identifiability of the model are established.
Simultaneous Critical Values For T-Tests In Very High Dimensions

This article considers the problem of multiple hypothesis testing using t-tests. The observed data are assumed to be independently generated conditional on an underlying and unknown two-state hidden model. We propose an asymptotically valid data-driven procedure to find critical values for rejection regions controlling k-family wise error rate (k-FWER), false discovery rate (FDR) and the tail probability of false discovery proportion (FDTP) by using one-sample and two-sample t-statistics. We only require finite fourth moment plus some very general conditions on the mean and variance of the population by virtue of the moderate deviations properties of t-statistics. A new consistent estimator for the proportion of alternative hypotheses is developed. Simulation studies support our theoretical results and demonstrate that the power of a multiple testing procedure can be substantially improved by using critical values directly as opposed to the conventional p-value approach. Our method is applied in an analysis of the microarray data from a leukemia cancer study that involves testing a large number of hypotheses simultaneously.
Simple amine/Pd(OAc)(2)-catalyzed suzuki coupling reactions of aryl bromides under mild aerobic conditions.

A new palladium catalyst (DAPCy) made from Pd(OAc)2 and commercially available, inexpensive dicyclohexylamine has been developed for the Suzuki coupling reaction of aryl bromides with boronic acids to give the coupling products in good to high yields. The air-stable catalyst was characterized and well-defined by X-ray crystallography. A catalytic system involving DAPCy in dioxane demonstrates a temperature-dependent reactivity toward aryl bromides with different electronic substituents, and selectively couples electron-deficient aryl bromides with boronic acids over electron-rich ones at room temperature. Another catalytic system employing DAPCy in EtOH provides a general and convenient method to prepare biaryls from aryl bromides and boronic acids with a broad range of functional groups at room temperature and under aerobic conditions.
Suggested research directions for a new frontier – active conceptual modeling

This paper discusses several research directions and challenges of a new frontier of research: active conceptual modeling. It suggests how the Entity-Relationship (ER) model may be extended to satisfy some of the needs of a new set of emerging user needs and applications.
Predictive Multiple Metrics in Proactive Mobile Ad Hoc Network Routing

In this paper we present a MANET proactive routing enhancement scheme by comprehensive evaluation of multiple dynamic routing metrics, including delay, energy cost, and link stability. We developed efficient routing metric prediction methods: predicting delay and energy using double exponential smoothing, and predicting link stability using a heuristic based on the normal-like distributions of the link lifetimes in typical MANET mobility scenarios. The routing metrics predictions are incorporated with regular routing information exchanges. On each node, routing table is constructed by a modified version of Dijkstra's algorithm, which evaluates the predicted metrics values compositively. We integrated such a multi-metric prediction/evaluation mechanism into OLSR and name it OLSR MC. We show by simulation that OLSR MC is more adaptive to the network dynamics and therefore is able to improve performance significantly on multiple routing objectives, including higher packet delivery ratio, shorter average end-to- end delay, and prolonged network energy lifetime.
Zero cycles on certain surfaces in arbitrary characteristic

Letk be a field of arbitrary characteristic. LetS be a singular surface defined overk with multiple rational curve singularities and suppose that the Chow group of zero cycles of its normalisation\(\tilde S\) is finite dimensional. We give numerical conditions under which the Chow group of zero cycles ofS is finite dimensional.
Tax policy and the missing middle: Optimal tax remittance with firm-level administrative costs☆

Abstract We analyze the optimal taxation of firms when the government faces fixed (per-firm) administrative costs of tax collection. The tax instruments at the government's disposal are a fixed (per-firm) fee and a linear tax on output. If all firms in an industry are taxed, we show that it is optimal to impose a positive fee to internalize administrative costs. The output taxes satisfy the inverse elasticity rule for taxed industries, but industries with sufficiently high administrative costs should be exempted from taxation. We also investigate the case where firms with outputs below a cutoff level can be exempted from taxation. It may be optimal to set the cutoff high enough to exempt a sizable number of firms, even though some firms reduce their outputs to the cutoff level, creating a “missing middle”: small and large firms – but not those of intermediate size – exist. Thus, this common phenomenon in developing countries may result from optimal policies. The paper also presents a modified inverse-elasticity rule when output cutoffs are used, and it extends the analysis to include optimal nonlinear taxes on output.
Combined Radiation and Conduction in Glass Foams

Understanding of heat transfer in glass foams and the development of theoretical tools for predicting heat transfer properties of glass foams is critical to improving the efficiency of glass manufacturing. In this paper, combined radiation and conduction heat transfer in a semitransparent glass foam layer is analyzed. The foam layer is thin and of the uniform thickness, bounded by hot combustion gases on top and glass melt on bottom, and exposed to isotropic radiation originating from hot refractories. Heat transfer is assumed to be one-dimensional perpendicular to the plane-parallel foam layer. A previously developed model is used to calculate effective extinction coefficients and scattering phase function of the foam layer using a void size distribution and assuming all voids to be spherical. These radiation properties are then used along with a Schuster-Schwarzchild two-flux approximation to solve the radiative transfer equation (RTE). A method for obtaining the effective thermal conductivity of the foam layer is also presented. The RTE and the energy conservation equations are simultaneously solved using a numerical iteration procedure. The effect of foam thickness and bubble size on the temperature distribution in the foam layer is studied.
Conversion of Aldoximes into Nitriles with Raney Nickel in Refluxing 2-Propanol

Abstract Aldoximes are readily dehydrated to nitriles with Raney nickel in refluxing 2-propanol.
Diurnal variation anomalies at Tucson

The seasonal changes in diurnal variation at Tucson, Arizona, are of unusual interest because of its location in the transition-belt where the type of diurnal variation changes markedly during the year. Monthly hodograms of the diurnal variation in Earth-current potential-gradient indicate that its changes are generally consistent with the recognized movement of the current systems in the ionosphere northward and southward with the sun. Two definite anomalies, less readily explained, are found to exist. The first is a marked increase in activity in January, which appears as a large increase in amplitude, and the second consists of a decrease and irregularity in the eastward component during March.
Entrapment of a dirhodium tetracarboxylate unit inside the aromatic bowl of a calix[4]arene: Unique catalysts for C–H amination

Unique calix[4]arene-derived, tetracarboxylate dirhodium(II) inclusion complexes have been prepared and evaluated as catalysts for C–H amination.
On the Number and Size of Nations

This paper studies the equilibrium determination of the number of countries in different political regimes, and in different economic environments, with more or less economic integration. We focus on the trade-off between the benefits of large jurisdictions and the costs of heterogeneity of large and diverse populations. Our model implies that (i) democratization leads to secessions; (ii) in equilibrium one generally observes an inefficiently large number of countries; (iii) the equilibrium number of countries is increasing in the amount of economic integration.
Thallium NMR spectroscopy

Keywords: 203Tl 205Tl; Chemical shifts; Spin-spin coupling; Relaxation Line width; Solid state
A SHORT, EFFICIENT SYNTHESIS OF MONOFLUORO KETOMETHYLENE PEPTIDE ISOSTERE CORE UNITS

Abstract Monofluoro ketomethylene peptide isosteres can be prepared by prepared by a four step sequence from carboxylic acids in satisfactory overall yields (30–60%). Fluorine is introduced by electrophilic fluorination of a β-ketoester enolate with SelectFluor TM .
Transformational Leadership And Organizational Culture

Nine types of organizational cultures are defined in terms of the extent transformational and transactional leadership and their effects form accepted ways of behaving. The Organizational Description Questionnaire (ODQ) is used by members of the organizations to describe their cultures. The nine types of organizations include the high-contrast culture with both strong transformational and transactional qualities to the "garbage can" which lacks either kind of leadership of consequence. A majority of organizations are somewhere inbetween either loosely guided, coasting, or contractual.
Energetics of rare-earth-doped hafnia

The enthalpies of formation of rare-earth (RE)-doped Hf1−xRExO2−x/2 solid solutions (RE = Sm, Gd, Dy, Yb; x = 0.25 to 0.62) with respect to the oxide end members, monoclinic HfO2 and C-type REO1.5, were determined using oxide melt solution calorimetry. The enthalpies of formation fit a function quadratic in composition. The strongly negative interaction parameters in all solid solutions confirm a strong tendency for short-range order. Though strongly negative for all systems, the interaction parameters become less negative with increasing ionic potential (decreasing RE radius). Crystallization energetics were investigated for amorphous coprecipitation products with x = 0.4. The energy difference between the crystalline (fluorite and pyrochlore) and amorphous phases decreases with decreasing dopant radius. This suggests that systems doped with small RE ions have more similar local structures in the fluorite and amorphous phases. These observations may result in a smaller kinetic barrier to recrystallization and account for the greater radiation resistance of materials with smaller RE cations.
Bayesian Grammar Induction for Language Modeling

We describe a corpus-based induction algorithm for probabilistic context-free grammars. The algorithm employs a greedy heuristic search within a Bayesian framework, and a post-pass using the Inside-Outside algorithm. We compare the performance of our algorithm to n-gram models and the Inside-Outside algorithm in three language modeling tasks. In two of the tasks, the training data is generated by a probabilistic context-free grammar and in both tasks our algorithm outperforms the other techniques. The third task involves naturally-occurring data, and in this task our algorithm does not perform as well as n-gram models but vastly outperforms the Inside-Outside algorithm.
Catalytic generation of activated carboxylates from enals: a product-determining role for the base.

N-Heterocycle carbenes generated in situ from imidazolium or triazolium salts and bases react with enals, leading to the catalytic generation of homoenolates. The fate of these intermediates is determined by the catalytic base: strong bases such as tBuOK lead to carbon−carbon bond formation, while weaker bases allow protonation of the homoenolate and subsequent generation of activated carboxylates. This discovery, along with the design of a new triazolium precatalyst, enables the catalytic, atom-economical redox esterification of enals.
HIBERNATION AND THE PITUITARY BODY

A train of symptoms, coupled with retardation of tissue metabolism and with inactivity of the reproductive glands, not only accompanies states of experimentally induced hypophysial deficiency, but is equally characteristic of clinical states of hypopituitarism. The more notable of these symptoms are a tendency, in the chronic cases, toward an unusual deposition of fat, a lowering of body temperature, slowing of pulse and respiration, fall in blood pressure, and oftentimes a pronounced somnolence. These symptoms bear a marked resemblance to the physiological phenomena accompanying the state of hibernation which have heretofore been unsatisfactorily ascribed solely to extracorporeal factors; namely, a seasonal deprivation of food and low temperature. In a series of hibernating animals (woodchucks) it has been found that during the dormant period histological changes are apparent in many of the ductless glands. The most notable of these changes occur in the pituitary body, as previously observed by Gemelli. The gland not only diminishes in size, but the cells of the pars anterior in some animals at least completely lose their characteristic staining reactions to acid and basic dyes. At the end of the dormant period the gland swells, and as the cells enlarge they again acquire their differential affinity for acid, basic, and neutral stains, and at the same time karyokinetic figures may appear.
Holders of the Purse Strings: Governance and Performance of Public Retirement Systems*

ABSTRACT Public sector pension plans are managed in diverse ways, with governance policies distinguished according to their board composition and size, how the trustees structure their investment decisions, what restrictio ns are placed on their investments, and whether they have independent performance evaluations. We examine how these governance policies affect pension investment strategies, and how those strategies in turn affect the funds’ financial performance. Metho ds . Drawing on two national surveys of state and local public retirement systems in 1992 and 1993, we ask if pension governance policies affect whether they (1) invest tactically in response to changing conditions; (2) allocate assets between equities and fixed -income holdings; (3) contract for external asset management; and (4) invest outside the U.S. Results . Empirical analysis reveals that governance policies – especially independent performance evaluations – predict investment decisions in all four a reas. These investment strategies are found in turn to affect subsequent fund performance: preferential investing in equities and abroad increased annual returns on their assets by as much as one to two percentage points. Conclusions . The ways that publ ic pensions are governed have a direct bearing on how they invest their assets, and the investment strategies in turn directly affect the financial performance of their holdings. Michael Useem is a professor of management in the Wharton School of the Un iversity of Pennsylvania, and director of its Center for Leadership and Change Management. He received his Ph.D. degree from Harvard University. His current research interests include ownership, governance, leadership, and change among companies and inve stors. Olivia S. Mitchell is a professor of insurance and risk management at the Wharton School of the University of Pennsylvania and executive director of its Pension Research Council. She received her Ph.D. degree from the University of Wisconsin. He r current research interests include the economics of pensions and retirement policy.
Consideration of spin states in determining the structure and decomposition of the transition metal pentazoles FeClN5, Fe(N5)2, Fe(H2O)4ClN5, and Fe(NH3)4ClN5

Optimised geometries and energies have been calculated for the unidentate, bidentate, and ferrocene-like structures of Fe(II) pentazoles of the form MN5 and M′(N5)2, (M = FeCl, M′ = Fe) using the UB3LYP DFT method with basis sets up to 6-311+G(3df) in order to study the effect of an unfilled d shell on the stability of the singlet, triplet, and quintet states; the ground state is a quintet and the quintet has a lower barrier to decomposition than the singlet.
Marx and Engels: In Praise of Globalization

Marx's vision of history unfolding is one of societal transformation from a set of diverse nation states in a capitalist world to a unified economic society in a yet-to-be communist world. The catalyst that sets this unfolding into action is the globalization process. Its trigger mechanism is the innovating capitalist. Enticed into creating new labor-saving technologies by the prospect of reaping higher rates of profit, these capitalists confront unavoidable competition and technology imitation which undermine their advantage and leads ultimately to falling prices and falling rates of profit. Their only recourse is to venture abroad, to globalize, to invest and produce in the less technologically developed economies. This globalization of resource and product markets is a dual-edged sword: It creates and destroys. It destroys the economic and social fabrics of the less developed economies and creates in its wake a replica of the more technologically advanced. In the end, we are all one global economy, western in character. Marx sees this inevitable globalization process as progressive and praiseworthy.
Dioxygen Activation at Non-Heme Iron: Insights from Rapid Kinetic Studies

One of the common biochemical pathways of binding and activation of dioxygen involves non-heme iron centers. The enzyme cycles usually start with an iron(II) or diiron(II) state and traverse via several intermediates (detected or postulated) such as (di)iron(III)-superoxo, (di)iron(III)-(hydro)peroxo, iron(III)iron(IV)-oxo, and (di)iron(IV)-oxo species, some of which are responsible for substrate oxidation. In this Account, we present results of kinetic and mechanistic studies of dioxygen binding and activation reactions of model inorganic iron compounds. The number of iron centers, their coordination number, and the steric and electronic properties of the ligands were varied in several series of well-characterized complexes that provided reactive manifolds modeling the function of native non-heme iron enzymes. Time-resolved cryogenic stopped-flow spectrophotometry permitted the identification of kinetically competent intermediates in these systems. Inner-sphere mechanisms dominated the chemistry of dioxygen binding, intermediate transformations, and substrate oxidation as most of these processes were controlled by the rates of ligand substitution at the iron centers.
Are There Economies of Scale in Underwriting Fees? Evidence of Rising External Financing Costs

This study examines the behavior of spreads paid in firm underwritten seasoned common stock offerings and straight bond offerings. Estimates indicate that up to 85% of the spread is variable cost and that the marginal spread is rising. Further, offerings that are likely to require greater underwriting services encounter higher marginal spreads. These findings are consistent with there being a family of U-shaped spreads, with lower quality offerings priced on higher spreads, unlike the economies of scale view of spreads. They agree with the views that underwriters provide valuable services and that the marginal cost of external finance is rising. In this article we address an important discrepancy between the received wisdom about the underwriter spread and the view of the spread from theories of underwriting. The spread is the compensation paid to the underwriter for selling the firm’s security issue, as a percent of the capital raised. The received wisdom is that there are important economies of scale in the issuance of new securities, an idea that is buttressed by many studies and panel data which show that larger issues have lower spreads than smaller issues. 1 Theories of underwriter certification, monitoring, and marketing suggest there are rising costs for these services, and thus that we should also observe many issuers that finance in the region of scale diseconomies in the spread.
Design for testability: today and in the future

Summary form only given. The author reviews the current techniques with a particular emphasis on today's Scan Designs. This entails distinguishing the differences between scan techniques, since all scans are not created equal! From this point the Testability Standards are discussed; these include the Boundary Scan activities and the Analog activities. Fault models are taking on more robust attributes, since the Stuck-At-Fault is necessary but not sufficient in today's technologies. The Delay Fault models are discussed with a comparison between a model which increases exponentially with gate count (Path Delay Fault) and one which increases linearly with gate count (Gate Delay Fault). Clearly, self-test is taking on an ever more important role which impacts both manufacturing testing and field system testing. The popular self-testing design techniques are shown. The interaction of testing and synthesis is discussed with a view on delay. Finally, the role of testing is explored in the new design environments which includes Hardware and Software Codesign.
Strong lensing constraints on the velocity dispersion and density profile of elliptical galaxies

We use the statistics of strong gravitational lensing from the Cosmic Lens All-Sky Survey to impose constraints on the velocity dispersion and density profile of elliptical galaxies. This approach differs from much recent work, where the luminosity function, velocity dispersion and density profile have been typically assumed in order to constrain cosmological parameters. It is indeed remarkable that observational cosmology has reached the point where we can consider using cosmology to constrain astrophysics, rather than vice versa. We use two different observables to obtain our constraints: total optical depth and angular distributions of lensing events. In spite of the relatively poor statistics and the uncertain identification of lenses in the survey, we obtain interesting constraints on the velocity dispersion and density profiles of elliptical galaxies. For example, assuming the singular isothermal sphere density profile and marginalizing over other relevant parameters, we find 168 σ ∗ 200 km s −1 (68 per cent confidence level), and 158 σ ∗ 220 km s −1 (95 per cent confidence level). Furthermore, if we instead assume a generalized Navarro‐Frenk‐White density profile and marginalize over other parameters, the slope of the profile is constrained to be 1.50 β 2.00 (95 per cent confidence level). We also constrain the concentration parameter as a function of the density profile slope in these models. These results are essentially independent of the exact knowledge of cosmology. We briefly discuss the possible impact on these constraints of allowing the galaxy luminosity function to evolve with redshift, and also possible useful future directions for exploration.
The Infinite Hidden Markov Random Field Model

Hidden Markov random field (HMRF) models are widely used for image segmentation, as they appear naturally in problems where a spatially constrained clustering scheme is asked for. A major limitation of HMRF models concerns the automatic selection of the proper number of their states, i.e., the number of region clusters derived by the image segmentation procedure. Existing methods, including likelihood- or entropy-based criteria, and reversible Markov chain Monte Carlo methods, usually tend to yield noisy model size estimates while imposing heavy computational requirements. Recently, Dirichlet process (DP, infinite) mixture models have emerged in the cornerstone of nonparametric Bayesian statistics as promising candidates for clustering applications where the number of clusters is unknown a priori; infinite mixture models based on the original DP or spatially constrained variants of it have been applied in unsupervised image segmentation applications showing promising results. Under this motivation, to resolve the aforementioned issues of HMRF models, in this paper, we introduce a nonparametric Bayesian formulation for the HMRF model, the infinite HMRF model, formulated on the basis of a joint Dirichlet process mixture (DPM) and Markov random field (MRF) construction. We derive an efficient variational Bayesian inference algorithm for the proposed model, and we experimentally demonstrate its advantages over competing methodologies.
Statistical Distributions and $q$-Analogues of $k$-Fibonacci Numbers

We study q -analogues of k -Fibonacci numbers that arise from weighted tilings of an $n\times1$ board with tiles of length at most k . The weights on our tilings arise naturally out of distributions of permutations statistics and set partitions statistics. We use these q -analogues to produce q -analogues of identities involving k -Fibonacci numbers. This is a natural extension of results of the first author and Sagan on set partitions and the first author and Mathisen on permutations. In this paper we give general q -analogues of k -Fibonacci identities for arbitrary weights that depend only on lengths and locations of tiles. We then determine weights for specific permutation or set partition statistics and use these specific weights and the general identities to produce specific identities.
Two-dimensional array beam scanning via externally and mutually injection-locked coupled oscillators

The use of arrays of injection-locked voltage-controlled oscillators coupled to nearest neighbors has been proposed as a means of controlling the aperture phase of one and two-dimensional (2-D) phased-array antennas. It has been demonstrated both theoretically and experimentally that one may achieve linear distributions of phase across a linear array aperture by injection locking to an external oscillator the end oscillators of an array of a mutually injection-locked oscillators. These linear distributions cause steering of the radiated beam. It is demonstrated theoretically here that one may achieve beamsteering in a similar manner in two dimensions by injecting appropriately phased signals into the perimeter oscillators of a 2-D array. The analysis is based on a continuum representation of the phase previously developed in the context of beamsteering via tuning of the perimeter oscillators.
Automizers as extended reflection groups

Abstract Let G be a finite group having an abelian Sylow p-subgroup P. Broue, Malle and Michel have shown that if G is a simple Chevalley group, then the automizer of P is an irreducible complex reflection group (for p not too small and different from the defining characteristic). The aim in this note is to show that a suitable version of this property holds for general finite groups.
False-Positive Psychology: Undisclosed Flexibility in Data Collection and Analysis Allows Presenting Anything as Significant

In this article, we accomplish two things. First, we show that despite empirical psychologists' nominal endorsement of a low rate of false-positive findings (≤ .05), flexibility in data collection, analysis, and reporting dramatically increases actual false-positive rates. In many cases, a researcher is more likely to falsely find evidence that an effect exists than to correctly find evidence that it does not. We present computer simulations and a pair of actual experiments that demonstrate how unacceptably easy it is to accumulate (and report) statistically significant evidence for a false hypothesis. Second, we suggest a simple, low-cost, and straightforwardly effective disclosure-based solution to this problem. The solution involves six concrete requirements for authors and four guidelines for reviewers, all of which impose a minimal burden on the publication process.
Pseudouridine profiling reveals regulated mRNA pseudouridylation in yeast and human cells

The modification of uridine to pseudouridine is widespread in transfer and ribosomal RNAs but not observed so far in a coding RNA; here a new technique is used to detect this modification on a genome-wide scale, leading to the identification of pseudouridylation in messenger RNAs as well as almost 100 new sites in non-coding RNAs. The modification of uridine to pseudouridine is widespread in transfer and ribosomal RNAs. Until now it had not been identified in a coding RNA. Wendy Gilbert and colleagues have employed a next-generation sequencing technique called Pseudo-seq to measure the uridine-to-pseudouridine modification on a genome-wide scale. They not only identify almost 100 new sites in non-coding RNAs, but also discover pseudouridylation in mRNAs. These modifications are mostly due to the activity of the Pus pseudouridine synthase family members, and they can be responsive to environmental conditions, suggesting that inducible modification of RNA might be another way to regulate transcription. Post-transcriptional modification of RNA nucleosides occurs in all living organisms. Pseudouridine, the most abundant modified nucleoside in non-coding RNAs1, enhances the function of transfer RNA and ribosomal RNA by stabilizing the RNA structure2,3,4,5,6,7,8. Messenger RNAs were not known to contain pseudouridine, but artificial pseudouridylation dramatically affects mRNA function—it changes the genetic code by facilitating non-canonical base pairing in the ribosome decoding centre9,10. However, without evidence of naturally occurring mRNA pseudouridylation, its physiological relevance was unclear. Here we present a comprehensive analysis of pseudouridylation in Saccharomyces cerevisiae and human RNAs using Pseudo-seq, a genome-wide, single-nucleotide-resolution method for pseudouridine identification. Pseudo-seq accurately identifies known modification sites as well as many novel sites in non-coding RNAs, and reveals hundreds of pseudouridylated sites in mRNAs. Genetic analysis allowed us to assign most of the new modification sites to one of seven conserved pseudouridine synthases, Pus1–4, 6, 7 and 9. Notably, the majority of pseudouridines in mRNA are regulated in response to environmental signals, such as nutrient deprivation in yeast and serum starvation in human cells. These results suggest a mechanism for the rapid and regulated rewiring of the genetic code through inducible mRNA modifications. Our findings reveal unanticipated roles for pseudouridylation and provide a resource for identifying the targets of pseudouridine synthases implicated in human disease11,12,13.
A counterexample to the strong version of Freedman's conjecture

A long-standing conjecture due to Michael Freedman asserts that the 4-dimensional topological surgery conjecture fails for non-abelian free groups, or equivalently that a family of canonical examples of links (the generalized Borromean rings) are not A - B slice. A stronger version of the conjecture, that the Borromean rings are not even weakly A - B slice, where one drops the equivariant aspect of the problem, has been the main focus in the search for an obstruction to surgery. We show that the Borromean rings, and more generally all links with trivial linking numbers, are in fact weakly A - B slice. This result shows the lack of a non-abelian extension of Alexander duality in dimension 4, and of an analogue of Milnor�s theory of link homotopy for general decompositions of the 4-ball.
Sex Offender Registries: Fear without Function?

AbstractI use three separate data sets and designs to determine whether sex offender registries are effective. First, I use state-level panel data to determine whether sex offender registries and public access to them decrease the rate of rape and other sexual abuse. Second, I use a data set that contains information on the subsequent arrests of sex offenders released from prison in 1994 in 15 states to determine whether registries reduce the recidivism rate of offenders required to register compared with the recidivism of those who are not. Finally, I combine data on locations of crimes in Washington, D.C., with data on locations of registered sex offenders to determine whether knowing the locations of sex offenders in a region helps predict the locations of sexual abuse. The results from all three data sets do not support the hypothesis that sex offender registries are effective tools for increasing public safety.
DECOMPOSING PRODUCER PRICE RISK: A POLICY ANALYSIS TOOL WITH AN APPLICATION TO NORTHERN KENYAN LIVESTOCK MARKETS

Abstract This paper introduces a simple method of price risk decomposition that determines the extent to which producer price risk is attributable to volatile inter-market margins, intra-day variation, intra-week (day of week) variation, or terminal market price variability. We apply the method to livestock markets in northern Kenya, a setting of dramatic price volatility where price stabilization is a live policy issue. In this particular application, we find that large, variable inter-market basis is the most important factor in explaining producer price risk in animals typically traded between markets. Local market conditions explain most price risk in other markets, in which traded animals rarely exit the region. Variability in terminal market prices accounts for relatively little price risk faced by pastoralists in the dry lands of northern Kenya although this is the focus of most present policy prescriptions under discussion.
Radical addition of diethyl (2-phenylseleno)propanedioate to olefins

Abstract The diethyl malonyl radical can be generated via the photolysis of diethyl (2-phenylseleno)propanedioate. This radical, in turn adds to olefins, and the radical chain process is propagated by phenyl selenide transfer, leading to products arising from formal addition of diethyl (2-phenylseleno)propanedioate.
Proxy ecology - Cooperative proxies with artificial life

Proxy servers have been widely used by institutions to serve their clients behind firewalls. Recently many schemes have been proposed to organize proxy servers into cooperative proxy cache systems. However most of existing proxy cache schemes require manual configuration of the cooperative proxies based on the network architecture. In this paper, we propose a novel P2P proxy caching scheme using an individual-based model. We borrow the ideas from the ecological system as well as the economical system to manage the cooperative proxies through data and information exchange among individual proxies. Proxies automatically configure themselves into a Virtual Proxy Graph. Data caching and data replication among the proxy nodes create artificial life in the proxies. The aggregate effect of caching and replicating actions by individual peer proxies forms a proxy ecology which automatically distributes data to nearest clients and balances workload. Our simulation results show that the proposed proxy caching scheme tremendously improves system performance. In addition, the individual-based design model ensures simplicity and scalability of the cache system.
UNSTEADY CASCADE AERODYNAMICS IN THE TIME DOMAIN

A linearized unsteady incompressible aerodynamic model for airfoil cascades is developed that is not restricted to harmonic motion at a constant interblade phase angle. This is accomplished by starting with the unsteady aerodynamic coefe cients generated by LINSUB, a semianalyticunsteady cascadeaerodynamics codethat assumes linearity in both space and time. An inverse Fourier transform is then performed to predict the unsteady aerodynamic forces on the airfoils due to an impulsive acceleration. This result, termed the cascade indicial function, is then convolved with the arbitrary motion of the blades to obtain the unsteady aerodynamic forces on the airfoils in the time domain. The aerodynamic damping predicted by the time domain model is shown to compare well to LINSUB results when the interblade phase angle is constant. Results demonstrating the ability of the model to handle arbitrary airfoil motion are also presented. Nomenclature
Asymptotic self‐similarity and wavelet estimation for long‐range dependent fractional autoregressive integrated moving average time series with stable innovations

. Methods for parameter estimation in the presence of long-range dependence and heavy tails are scarce. Fractional autoregressive integrated moving average (FARIMA) time series for positive values of the fractional differencing exponent d can be used to model long-range dependence in the case of heavy-tailed distributions. In this paper, we focus on the estimation of the Hurst parameter H = d + 1/α for long-range dependent FARIMA time series with symmetric α-stable (1 < α < 2) innovations. We establish the consistency and the asymptotic normality of two types of wavelet estimators of the parameter H. We do so by exploiting the fact that the integrated series is asymptotically self-similar with parameter H. When the parameter α is known, we also obtain consistent and asymptotically normal estimators for the fractional differencing exponent d = H − 1/α. Our results hold for a larger class of causal linear processes with stable symmetric innovations. As the wavelet-based estimation method used here is semi-parametric, it allows for a more robust treatment of long-range dependent data than parametric methods.
Linear Stability Analysis of a Hot Plasma in a Solid Torus

This paper is a first step toward understanding the effect of toroidal geometry on the rigorous stability theory of plasmas. We consider a collisionless plasma inside a torus, modeled by the relativistic Vlasov–Maxwell system. The surface of the torus is perfectly conducting and it reflects the particles specularly. We provide sharp criteria for the stability of equilibria under the assumption that the particle distributions and the electromagnetic fields depend only on the cross-sectional variables of the torus.
Thiol–Ene Click Chemistry

Following Sharpless' visionary characterization of several idealized reactions as click reactions, the materials science and synthetic chemistry communities have pursued numerous routes toward the identification and implementation of these click reactions. Herein, we review the radical-mediated thiol-ene reaction as one such click reaction. This reaction has all the desirable features of a click reaction, being highly efficient, simple to execute with no side products and proceeding rapidly to high yield. Further, the thiol-ene reaction is most frequently photoinitiated, particularly for photopolymerizations resulting in highly uniform polymer networks, promoting unique capabilities related to spatial and temporal control of the click reaction. The reaction mechanism and its implementation in various synthetic methodologies, biofunctionalization, surface and polymer modification, and polymerization are all reviewed.
Who supports global economic engagement? The sources of preferences in American foreign economic policy

In this article we bring together opposing international relations theories to better understand U.S. foreign policy, in particular foreign trade and aid. Using votes in the U.S. House of Representatives from 1979–2004, we explore different theoretical predictions about preferences for foreign economic policy. We assess the impact of domestic factors, namely political economy and ideological preferences, versus foreign policy pressures. Our three main results highlight the differential effect of these factors in the two issue areas. First, aid preferences are as affected by domestic political economy factors as are trade preferences. Second, trade preferences, but not economic aid ones, are shaped by the president's foreign policy concerns; for economic aid, domestic political economy factors matter more than foreign policy ones. Third, aid preferences are shaped more by ideological factors than are trade ones, but ideology plays a different substantive role in each. Different constituencies support aid and trade. This finding has implications for foreign policy substitutability, “the internationalist coalition” in U.S. foreign policy, “statist” theories of foreign policy, and the connection between public opinion and legislative voting.
China's Profits and Losses from Currency Intervention, 1994–2011

China’s currency policy has been criticized for its apparent pursuit of mercantile advantage by artificially stimulating exports, which potentially have adverse effects on other economies. While China’s currency policy may have positive output effects, there may be additional profits or losses. This paper computes the annual and cumulative accounting profits from currency intervention since 1994 when China began its currency intervention. It is shown that profits initially were positive but China since 2007 has lost a massive amount from the currency market. JEL-Code: F100.
Highly Magnetic Core–Shell Nanoparticles with a Unique Magnetization Mechanism

Magnetic nanoparticles (MNPs) with high magnetic moments and very small size are under active development, since such materials have growing uses in biotechnology and medicine.[1] Ferromagnetic metals, rather than their corresponding oxides, have been suggested as an ideal constituent for MNPs for their superior magnetization.[2] Unfortunately, monometallic MNPs typically require protective layers to prevent progressive oxidation. To date, however, most core/shell approaches have yielded suboptimal magnetization, as the shell was formed either by artificially oxidizing the core[3,4] or by coating it with non-magnetic materials.[5]
Stereocontrolled syntheses of C-linked deoxyribosides of 2-hydroxypyridine and 2-hydroxyquinoline

Abstract 2′-Deoxy-C-ribosides 45 were prepared in optically active form by a route expected to be generally us for the synthesis of the α- or β-anomers of 2′-deoxy-C-ribosides. Key steps are the addition of an organometallic reagent to aldehyde 7 , mesylation of the resulting alcohol, and stereospecific deprotection/cyclization to yield the 2′-deoxy-C-riboside ( 7+8 → 9/10;9 → 11 ).
A Novel Highly Stereoselective Synthesis of 2,3-Disubstituted 3H-Quinazoline-4-one Derivatives

An efficient three-step synthesis of chiral 3H-quinazoline-4-one derivatives from commercial materials is disclosed. The Mumm reaction of imidoyl chloride with α-amino acids followed by reductive cyclization affords enantiomerically pure (ee >93%) quinazoline-4-ones in good overall yield. A comparison with existing approaches indicates that this method is superior for hindered substrates.
Alkyne–Aldehyde Reductive C–C Coupling through Ruthenium-Catalyzed Transfer Hydrogenation: Direct Regio- and Stereoselective Carbonyl Vinylation to Form Trisubstituted Allylic Alcohols in the Absence of Premetallated Reagents

Nonsymmetric 1,2-disubstituted alkynes engage in reductive coupling to a variety of aldehydes under the conditions of ruthenium-catalyzed transfer hydrogenation by employing formic acid as the terminal reductant and delivering the products of carbonyl vinylation with good to excellent levels of regioselectivity and with complete control of olefin stereochemistry. As revealed in an assessment of the ruthenium counterion, iodide plays an essential role in directing the regioselectivity of C–C bond formation. Isotopic labeling studies corroborate reversible catalytic propargyl C–H oxidative addition in advance of the C–C coupling, and demonstrate that the C–C coupling products do not experience reversible dehydrogenation by way of enone intermediates. This transfer hydrogenation protocol enables carbonyl vinylation in the absence of stoichiometric metallic reagents.