cssi/SciSciGPT-SciSciNet huggingface dataset:
9‐Membered Carbocycle Formation: Development of Distinct Friedel–Crafts Cyclizations and Application to a Scalable Total Synthesis of (±)‐Caraphenol A

While forming any medium-sized ring requires an approach capable of overcoming significant entropic and enthalpic penalties,[1] the challenge in meeting that requirement is often more pronounced in systems composed only of carbon atoms, such as the 9-membered rings of caraphenol A (1)[2] and α-viniferin (2),[3] two oligomeric forms of the natural product resveratrol (3)[4,5] which are bioactive (including acetylcholinesterase inhibition, anti-inflammatory properties, and potential value as probes for elucidating key pathways in Alzheimer’s disease and drug resistance in tumors).[6] Indeed, without the more obvious and established array of productive cyclization strategies afforded by heteroatoms, only a handful of approaches have proven capable of accessing fully carbocyclic variants. For 9-membered rings, that includes Grob fragmentations (such as 4→5),[7] highly context specific C–C bond constructions such as the acetylide addition leading to enediyne 6,[8] and ring-closing olefin metathesis (not shown).[9] Given this landscape, as well as the unique and sp2-rich patterning of 1 and 2 (and 11 other related molecules)[10] that effectively precludes the application of these three established strategies, we sought to identify additional approaches capable of forging strained, 9-membered carbocycles. Herein, we show that a variety of Friedel–Crafts-type reactions promoted by either Au(III) or Br∅nsted acids are competent in this regard with functionally rich substrates. In addition to providing what we believe is the first example of a 9-exo-dig ring closure, late-stage application of one of the developed approaches has enabled the completion of an efficient and highly scalable total synthesis of caraphenol A (1).
Modulation rate adaptation in urban and vehicular environments: cross-layer implementation and experimental evaluation

Accurately selecting modulation rates for time-varying channel conditions is critical for avoiding performance degradations due to rate overselection when channel conditions degrade or underselection when channel conditions improve. In this paper, we design a custom cross-layer framework that enables: 1) implementation of multiple and previously unimplemented rate adaptation mechanisms; 2) experimental evaluation and comparison of rate adaptation protocols on controlled, repeatable channels as well as residential urban and downtown vehicular and nonmobile environments in which we accurately measure channel conditions with 100- s granularity; and 3) comparison of performance on a per-packet basis with the ideal modulation rate obtained via exhaustive experimental search. Our evaluation reveals that SNR-triggered protocols are susceptible to overselection from the ideal rate when the coherence time is low (a scenario that we show occurs in practice even in a nonmobile topology), and that “in situ” training can produce large gains to overcome this sensitivity. Another key finding is that a mechanism effective in differentiating between collision and fading losses for hidden terminals has severely imbalanced throughput sharing when competing links are even slightly heterogeneous. In general, we find trained SNR-based protocols outperform loss-based protocols in terms of the ability to track vehicular clients, accuracy within outdoor environments, and balanced sharing with heterogeneous links (even with physical layer capture).
Mature markets and revitalization strategies: An American fable

O nce upon a time, in a land called the United States of America, there existed a business system within which companies prospered. For many years, it seemed that these companies could do no wrong, Regardless of the type or variety of products made, everyone wanted to be first in line to buy one. Over the years, there was a continuous flow of new ideas from which innovations sprang forth. Companies in this system grew and prospered. Sales kept rising and profits continued to increase. All was well. One day, someone from a faraway place visited this land. He marveled at the successes being enjoyed by all these companies and wondered why they did so well. It was apparent to him that, with a little hard work, numerous improvements could be made. Further, he observed that while the products continued to be bought in large quantities, there seemed to be few efforts made by the companies to ask the people of this land what they really wanted. Far from being happy with their purchases, it seemed that most products were bought because few alternatives existed. Being the curious person he was, he asked managers of the producing companies why they did not make these small efforts to really please the populace. The reply was, "Why should we? Where else could they buy such wonderful items as those we produce?" The visitor realized then that should he go back home and produce a better product, he might be very successful in America. At the same time, a wizard visited this land. Although everyone thought the wizard possessed the ability to see into the future, the wizard himself knew better. He recognized that the success of his prophecies was not due to any mystical powers, but rather came from the persuasive manner in which he conveyed his message. People were so awed by his words that they began to take actions, which in essence caused his prophecies to become selffulfilling. The wizard was invited to speak before a meeting of managers representing most of the maAmerican businesses need to stop fulfilling their own prophecies of product and market decline and instead revitalize those products and markets.
An integer programming approach to the construction of trend-free experimental plans on split-plot designs

Abstract In many experimental designs, the standard procedure involves randomization of the factor-level combination run order. There are cases, however, where it is known that a time or position trend that can seriously compromise the results of the experiment may be present. These trends include wear of tooling and equipment, learning curves, change in temperatures, and so on, and the trends may show up as linear, quadratic, or even higher order trends. All previously published work has dealt with various methods of constructing trend-resistant run order plans on full and fractional factorial designs. These previous efforts have not addressed any additional dimensions in the trends that emerge when using hierarchical designs such as split-plot plans. These designs are common in many manufacturing experiments where complete randomization is not possible or is too expensive to be practical. The objective of this work is to establish the foundations of a method for constructing linear and quadratic trend-resistant plans in two-level split-plot designs that addresses the two-dimensional trends that may occur. The methodology involves development of a hybrid approach using the foldover method in each of the dimensions of interest and embedding these in a nonlinear integer programming model in the search for a feasible solution. Feasibility of this approach is shown for the particular case of a split-plot design (2 5 whole-plot factors and 3 1 × 2 1 split-plot factors) performed on abrasive machining. In this case study, an experimental plan that is robust against all linear trends and most quadratic trends was achieved.
Improving Image Retrieval Effectiveness via Multiple Queries

Conventional approaches to image retrieval are based on the assumption that relevant images are physically near the query image in some feature space. This is the basis of the cluster hypothesis. However, semantically related images are often scattered across several visual clusters. Although traditional Content-based Image Retrieval (CBIR) technologies may utilize the information contained in multiple queries (gotten in one step or through a feedback process), this is often only a reformulation of the original query. As a result most of these strategies only get the images in some neighborhood of the original query as the retrieval result. This severely restricts the system performance. Relevance feedback techniques are generally used to mitigate this problem. In this paper, we present a novel approach to relevance feedback which can return semantically related images in different visual clusters by merging the result sets of multiple queries. We also provide experimental results to demonstrate the effectiveness of our approach.
Spanwise Variation in the Unsteady Stalling Flowfields of Two-Dimensional Airfoil Models

Recent investigations of two-dimensional airfoil stalling characteristics have revealed low-frequency and highly unsteady e owin somecases and large-scalethree-dimensionalstructuresin other cases.Thelatterwerereferred to as “ stall cells” and can form on two-dimensional cone gurations where the ends of the airfoil model are e ush with tunnelsidewallsorend plates.Thispaperpresentsresultsofdetailedinvestigationsofthestalling characteristicsof several airfoils that exhibited both low-frequency unsteadiness and large-scale three-dimensional structures. The airfoils were wind-tunnel tested in a two-dimensional cone guration. The primary measurements were spanwise wakevelocityand mini-tufte owvisualization. Theresultsshowedthatairfoilswithtrailing-edgeseparationsatand above maximum lift (static stall )exhibited stall-cell patterns. Conversely, airfoils that had leading-edge separation bubblesthatgrewinsizeastheangleofattackwasincreasedintostalldevelopedthelow-frequency,highlyunsteady e ow. This unsteadiness was found to be essentially two dimensional. Therefore, the development of either of these phenomenaappearstobedeterminedbythecharacteristicsoftheboundary-layerseparationleadinguptothestall.
Economic stress and cigarette smoking: Evidence from the United States ☆

Abstract This paper uses pooled data on U.S. states for the post-MSA period to estimate the demand for cigarettes, with the main contribution lying in considering the effects of economic stress/uncertainty. Different measures of economic stress – standard deviations and averages of unemployment and property prices – are considered. Greater economic stress is found to lower cigarette smoking across various specifications. Other findings largely support the literature on cigarette demand — price effects are negative, border price effects are positive and the effect of income is negative.
Ignition of aluminum powders by electro-static discharge

Abstract Metal powder heating and ignition by an electro-static discharge, ESD (or spark) was investigated. For different spark voltages, ESD discharge energies transferred to the powder samples and respective spark radii are evaluated experimentally. Al powder was chosen as a popular metal fuel additive for many energetic formulations, and as a metal, for which spark initiation typically results in ignition of individual particles rather than in an aerosol flame consuming bulk of the powder. Al powders with nominal particle sizes of 3–4.5 μm and 10–14 μm were used in experiments. The finer powder was found to be strongly agglomerated while almost no agglomeration was observed for the coarser powder. Emission streaks produced by an empty steel sample holder struck by the spark and by the spark-heated and ignited Al particles were detected and differentiated. Emission traces of burning particles were acquired by a photodiode to determine burn times for the particles ignited by sparks with different energies. From the burn times, particle diameters were estimated using correlations reported in the literature. Burn times for the ignited Al particles clearly correlated with the Joule heat energy for the coarser (nom. 10–14 μm) powder, while the correlation was tentative for the finer powder used in this work. The results are interpreted considering the particle size distributions and assuming that particles are Joule heated so that the heating is more efficient for finer particles, with greater surface to volume ratio. It is further suggested that strong agglomeration observed for the finer Al powder skewed the expected correlation between the Joule heating energy and the size of ignited particles. Current experiments suggest several additional practical conclusions. The mechanisms of powder ejection and ignition by the ESD are not directly related to each other. The commonly considered minimum ignition energy is not a useful powder characteristic and depends strongly on the optical diagnostics used. It is proposed that more useful and readily measured quantitative indicators of the powder ignition sensitivity are the burn time of the particles ignited by the spark and the distance the burning particles travel, which respectively quantify how long and how far reaching is the spark’s ignition stimulation. Both parameters should be quantified for a specific spark energy or energy range.
Recent measurements of coherent transition radiation

Abstract An extended series of experiments has been used to investigate transition radiation in the X-ray spectral region. The X-rays were generated at the Lawrence Livermore National Laboratory electron-positron linear accelerator by 54 MeV electrons traversing multiple thin-foil targets. The measured angular and spectral distributions have shown excellent agreement with calculated predictions based on a simplified theoretical description of transition radiation. Recently, energy-resolved measurements of X-ray generation by targets consisting of multiple closely-spaced foils has clearly demonstrated the longitudinal coherence of transition radiation. This behavior might lead to a variety of applications such as tuneable narrow-band X-ray sources, measurement of X-ray dielectric constants, or particle beam diagnostics. These issues will be discussed and recent results will be presented.
Basins of Attraction, Long-Run Stochastic Stability, and the Speed of Step-by-Step Evolution

The paper examines the behaviour of ‘‘evolutionary’’ models with e-noise like those which have been used recently to discuss the evolution of social conventions. The paper is built around two main observations: that the ‘‘long run stochastic stability’’ of a convention is related to the speed with which evolution toward and away from the convention occurs, and that evolution is more rapid (and hence more powerful) when it may proceed via a series of small steps between intermediate steady states. The formal analysis uses two new measures, the radius and modified coradius, to characterize the long run stochastically stable set of an evolutionary model and to bound the speed with which evolutionary change occurs. Though not universally powerful, the result can be used to make many previous analyses more transparent and extends them by providing results on waiting times. A number of applications are also discussed. The selection of the risk dominant equilibrium in 2B2 games is generalized to the selection of 1 2-dominant equilibria in arbitrary games. Other applications involve two-dimensional local interaction and cycles as long run stochastically stable sets.
The age distribution of massive star clusters in the antennae galaxies

We determine the age distribution of star clusters in the Antennae galaxies (NGC 4038/9) for two mass-limited samples (M > 3 × 104 M☉ and M > 2 × 105 M☉). This is based on integrated broadband UBVI and narrowband Hα photometry from deep images taken with the Hubble Space Telescope. We find that the age distribution of the clusters declines steeply, approximately as dN/dτ ∝ τ-1. The median age of the clusters is ~107 yr, which we interpret as evidence for rapid disruption ("infant mortality"). It is very likely that most of the young clusters are not gravitationally bound and were disrupted near the times they formed by the energy and momentum input from young stars to the interstellar matter of the protoclusters. At least 20% and possibly all stars form in clusters and/or associations, including those that are unbound and short-lived.
Binary droplet collisions in a vacuum environment: an experimental investigation of the role of viscosity

An experimental investigation of viscous binary droplet collisions in a vacuum environment is conducted. The fundamental ramifications of conducting such experiments in a vacuum environment are twofold. The first, which is the motivating factor of this work, assures that the collision products are unimpeded by aerodynamic effects which tend to disrupt the collision process at a much earlier stage in the processes than if they were absent, and second, the phenomenon of encapsulation of the host medium between the colliding droplets is not present in this study; a fact that limits the scope of direct application of this study to a number of (but not all) applications. Droplets are generated from capillary stream breakup with the imposition of an amplitude-modulated disturbance which results in the generation of highly uniform pre-collision drops at separations far extending those which are possible from a standard (monochromatic) sinusoidal disturbance. Hence, the collision products are able to deform unimpeded by interactions with neighboring collision products. Measurements over a broad range of Weber number, We, indicate that the value of the critical Weber number, We c, is more than 100 times greater for the 30-cSt fluid than the corresponding value for similarly sized water drops in a standard ambient environment. Measurements of the oblate and prolate half-cycle oscillation periods resulting from the binary collision reveal a distinct behavior that is observed and documented here for the first time. Additionally, measurements of the radial extent of the deformed mass at the instant of maximum deformation have been conducted and allow quantification of the energy dissipation. These measurements show that the energy dissipation increases with increasing fluid viscosity, which contradicts the results published by others.
Hypervalent Iodine Oxidation of Hydrazine Hydrate in Dichloromethane. A New Method for Diimide Generation

Abstract Diimide reduction of olefins, an alkyne and an azo compound using C5H5I(OAc)2/CH2Cl2 at room temperature is reported.
An Excursion into the Intriguing World of Polymeric Tl(I) and Ag(I) Cyanoximates

The reaction of hot (~95 °C) aqueous solutions of Tl2CO3 with solid HL (HL = NC-C(=N-OH)-R is a cyanoxime, and R is an electron-withdrawing group; 37 ligands are known up-to-date) leads to crystalline yellow/orange TlL. Similarly, the reaction between AgNO3 and ML (M = K+, Na+; L = anion of the monodeprotonated cyanoxime) this time at room temperature in mixed ethanol/aqueous solutions leads to sparingly soluble, colored AgL in high-yield. All synthesized monovalent Tl and Ag complexes were characterized using a variety of spectroscopic methods and X-ray analysis, which revealed the formation of primarily 2D coordination polymers of different complexity. In all cases cyanoxime mono-anions act as bridging ligands. Thallium(I) cyanoximates adopt in most cases a double-stranded motif that is originated from centrosymmetric (TlL)2 dimers in which two Tl2O2 rhombs are fused into infinite “ladder-type” structure. There are very short (3.65–3.85 A) intermetallic distances in (TlL)n, which are close to that (3.46 A) in metallic thallium. This opens the possibility for the electrochemical or chemical generation of mixed valence Tl(I)/Tl(III) polymers that may exhibit electrical conductivity. Synthesized silver(I) compounds demonstrate a very significant (for multiple years!) stability towards visible light. There are three areas of potential practical applications of these unusual complexes: (1) battery-less detectors of UV-radiation, (2) non electrical sensors for gases of industrial importance, (3) antimicrobial additives to light-curable acrylate polymeric glues, fillers and adhesives used during introduction of indwelling medical devices. Chemical, structural, technological and biological aspects of application of Tl(I) and Ag(I) cyanoximes-based coordination polymers are reviewed.
A Bivariate Timing Model of Customer Acquisition and Retention

Two widely recognized components, central to the calculation of customer value, are acquisition and retention propensities. However, while extant research has incorporated such components into different types of models, limited work has investigated the kinds of associations that may exist between them. In this research, we focus on the relationship between a prospective customer's time until acquisition of a particular service and the subsequent duration for which he retains it, and examine the implications of this relationship on the value of prospects and customers. To accomplish these tasks, we use a bivariate timing model to capture the relationship between acquisition and retention. Using a split-hazard model, we link the acquisition and retention processes in two distinct yet complementary ways. First, we use the Sarmonov family of bivariate distributions to allow for correlations in the observed acquisition and retention times within a customer; next, we allow for differences across customers using latent classes for the parameters that govern the two processes. We then demonstrate how the proposed methodology can be used to calculate the discounted expected value of a subscription based on the time of acquisition, and discuss possible applications of the modeling framework to problems such as customer targeting and resource allocation.
Trade and Empire

We employ a new database of over 21,000 bilateral trade observations from 1870–1913 to assess the contemporaneous effects of empire on trade. Our analysis shows that belonging to an empire roughly doubled trade relative to those countries that were not part of an empire. The use of a common language, the establishment of currency unions, the monetisation of recently acquired colonies, and the establishment of preferential trade agreements and customs unions help to account for the observed increase in trade associated with empire.
Exact Bianchi identity in Regge gravity

In the continuum the Bianchi identity implies a relationship between different components of the curvature tensor, thus ensuring the internal consistency of the gravitational field equations. In this paper the exact form for the Bianchi identity in Regge's discrete formulation of gravity is derived, by considering appropriate products of rotation matrices constructed around null-homotopic paths. The discrete Bianchi identity implies an algebraic relationship between deficit angles belonging to neighbouring hinges. As in the continuum, the derived identity is valid for arbitrarily curved manifolds without a restriction to the weak field small curvature limit, but is in general not linear in the curvatures.
Are Bilateral Remittances Countercyclical

By putting together a relatively large data set on bilateral remittances of emigrants, this paper is able to shed light on the important hypothesis of smoothing. The smoothing hypothesis is that remittances are countercyclical with respect to income in the worker’s country of origin (the recipient of the remittance), while procyclical with respect to income in the migrant’s host country (the sender of the remittance). The econometric results confirm the hypothesis. This affirmation of smoothing is important for two reasons. First, it suggests that remittances should be placed on the list of criteria for an optimum currency area. Second, it brings into doubt plans by governments in some developing countries to harness remittances for their own use, in that government spending in these countries generally fails the test of countercyclicality which remittances pass.
MLSE equalization and decoding for multipath-fading channels

The performance of a receiver using a combined MLSE (maximum likelihood sequence estimation) equalizer/decoder and D-diversity reception is analyzed for multipath Rayleigh fading channels. An upper bound on the (decoded) bit error probability is derived. Comparisons to simulation results show that this upper bound is quite tight when the system has a high signal-to-noise ratio or when diversity reception is used. The upper bound involves an infinite series that must be truncated at a point where the remainder can be safely assumed to be small. An algorithm based on a one-directional stack algorithm is proposed for this calculation because it makes efficient use of computer memory. >
DSP architectures, algorithms, and code-generation: fission or fusion?

Continuing dramatic improvements in semiconductor manufacturing processes are enabling radical new signal-processing architectures at the chip level. The development of these new architectures must be coupled, a fusion, with clearly defined target applications, a thorough analysis of applicable signal processing algorithms, and significant advancements in code-generation technology. The TMS320C6x development program involved the codevelopment of the VelociTI architecture, a new code-generation environment, and a large set of representative benchmarks.
A picture is worth a thousand words: and it costs...

The present is a critical, frustrating, and exciting time in the history of computer graphics. A dozen significant trends are developing in the same field of view. Several much-needed trends are not developing. The technology is changing so rapidly that four generations of graphical systems are in operation at once. "Computer graphics" means different things to different people. This is therefore a difficult session to "introduce."
Non-Archimedean subjective probabilities in decision theory and games

Abstract To allow conditioning on counterfactual events, zero probabilities can be replaced by infinitesimal probabilities that range over a non-Archimedean ordered field. This paper considers a suitable minimal field that is a complete metric space. Axioms similar to those in Anscombe and Aumann [Anscombe, F.J., Aumann, R.J., 1963. A definition of subjective probability, Annals of Mathematical Statistics 34, 199–205.] and in Blume et al. [Blume, L., Brandenburger, A., Dekel, E., 1991. Lexicographic probabilities and choice under uncertainty, Econometrica 59, 61–79.] are used to characterize preferences which: (i) reveal unique non-Archimedean subjective probabilities within the field; and (ii) can be represented by the non-Archimedean subjective expected value of any real-valued von Neumann–Morgenstern utility function in a unique cardinal equivalence class, using the natural ordering of the field.
A convenient method for the synthesis of unsymmetrical 3,4-disubstituted pyrroles

Abstract A simplified procedure for the synthesis of 3,4-dibromo-1-[tris(1-methylethyl)silyl]-1H-pyrrole ( 2 ) is described together with its sequential halogen-metal exchange chemistry to afford 3,4-disubstituted pyrroles.
The development of fundulus heteroclitus embryos in solutions of metrazol

Speidel1 has attempted to ascertain the specific effect of metrazol on the nervous system by immersing frog tadpoles in aqueous solutions of it and by studying, by direct microscopic and cine-photomicrographic methods, the outgrowth of living nerve fibers in the tadpoles'tails. Using a 2% solution for approximately 20 minutes, Speidel found that the growing nerve endings degenerated during the period of immersion, but recovered and subsequently regenerated when the tadpoles were returned to pond-water.The present communication reports the results of studying the development of certain aspects of gross behavior in whole embryos (Fundulus heteroclitus) which were immersed in solutions of metrazol at different stages of development and which remained in them for varying periods of time. The investigation was undertaken with the possibility in mind that subjecting embryos to treatment at various stages of development might produce alterations of structure and function in the central nervous system which could...
The “CAPS” Prediction System and Stock Market Returns

We study approximately 5.0 million stock picks submitted by individual users to the "CAPS" website run by the Motley Fool company (www.caps.fool.com). These picks prove to be surprisingly informative about future stock prices. Shorting stocks with a disproportionate number of negative picks and buying stocks with a disproportionate number of positive picks yields a return of over 12% per annum over the sample period. Negative picks mostly drive these results; they strongly predict future stock price declines. Returns to positive picks are statistically indistinguishable from the market. A Fama–French decomposition suggests that stock-picking rather than style factors largely produced these results.
FAST-Net optical interconnection prototype demonstration

The first prototype of the free-space accelerator for switching terabit networks (FAST-Net) program is described. The optical interconnection module consists of an array of matched high-resolution, wide-angle (f/1.1) imaging lenses that effect a global point-to-point shuffle link pattern across a multichip smart pixel array. A mirror is used to fold the shuffled links back onto the array to facilitate single-plane multichip packaging and simplified opto-mechanical alignment. The test system incorporates several monolithically integrated two-dimensional arrays of vertical-cavity surface-emitting lasers (VCSELs) and photodetectors (PDs) in the multichip plane. In initial experiments the prototype showed good overall optical efficiency and sufficient channel separation for VCSEL/PD arrays with pitches as small as 100 m. These results suggest that high bisection bandwidth optical free-space interconnection fabrics are feasible for high-throughput switching and multiprocessor applications.
Spatial Indices of Segregation

Segregation is commonly measured by means of an index of dissimilarity. A recent 'boundary modified' version of the index was formulated. It was based upon the concept that segregation is a separation created by spatial structure imposed upon the social space and thus interaction between racial groups is limited. The index takes into account one of the spatial etements—contiguity—but ignores the others. This paper argues that the length of the common boundary between two areal units and the shape of the areal units are important spatial components in determining segregation. Thus, a family of segregation indices is derived by incorporating these spatial components and can be applied to various spatial configurations. One of the indices possesses a distinctive property which is useful for comparing segregation levels in regions of various scales.
Energy Efficiency Economics and Policy

Energy efficiency and conservation are considered key means for reducing greenhouse gas emissions and achieving other energy policy goals, but associated market behavior and policy responses have engendered debates in the economic literature. We review economic concepts underlying consumer decision making in energy efficiency and conservation and examine related empirical literature. In particular, we provide an economic perspective on the range of market barriers, market failures, and behavioral failures that have been cited in the energy efficiency context. We assess the extent to which these conditions provide a motivation for policy intervention in energy-using product markets, including an examination of the evidence on policy effectiveness and cost. Although theory and empirical evidence suggests there is potential for welfare-enhancing energy efficiency policies, many open questions remain, particularly relating to the extent of some key market and behavioral failures.
Labeled Search Trees and Amortized Analysis: Improved Upper Bounds for NP-Hard Problems

A sequence of exact algorithms to solve the Vertex Cover and Maximum Independent Set problems have been proposed in the literature. All these algorithms appeal to a very conservative analysis that considers the size of the search tree, under a worst-case scenario, to derive an upper bound on the running time of the algorithm. In this paper we propose a different approach to analyze the size of the search tree. We use amortized analysis to show how simple algorithms, if analyzed properly, may perform much better than the upper bounds on their running time derived by considering only a worst-case scenario. This approach allows us to present a simple algorithm of running time O(1.194kk2 + n) for the parameterized Vertex Cover problem on degree-3 graphs, and a simple algorithm of running time O(1.1255n) for the Maximum Independent Set problem on degree-3 graphs. Both algorithms improve the previous best algorithms for the problems.
Online Support Services for Undergraduate Millennial Students

Education has changed as a result of technological advances. Distance learning, particularly online learning, has rapidly increased its presence in higher education. Millennials, a new generation of students who have grown up with the Internet, are college-age. They expect access to the Internet to manage their daily lives. However, as they enter college, many discover that support services that are requisite to a successful college experience, are available on-campus but not online. The goal was to determine what contemporary college-aged students expect as online student support services so that institutions will know what to provide. Data gathered through interviews with administrative support staff were used to modify a published survey and to guide construction of new questions. The modified instrument was validated by three experts and revised accordingly. All current students at Farmingdale State College were invited to respond to the web-based instrument that examined the current status of online support services. Following full-scale implementation, the data were analyzed. Results were used to create recommendations and considerations for the implementation of online support services at the college reviewed by the Vice President of Student Affairs and Enrollment Management. The final report is a comprehensive resource for college administrators who serve millennial undergraduates. It contains valuable information and guidance for the development and implementation of student support services in the 21 st century. A serendipitous finding was that many non-traditional, older
A subsidized Vickrey auction for cost sharing

We introduce a subsidized Vickrey auction for cost sharing problems. Although the average, marginal, and serial cost sharing mechanisms are budget-balanced, they are not allocatively efficient and they do not induce players to truthfully reveal their values as a dominant strategy. The conventional Vickrey auction, on the other hand, is allocatively efficient and does induce truthful bidding as a dominant strategy, but also generates an overpayment. This paper modifies the conventional Vickrey auction so that some of the overpayment is used to subsidize additional production without upsetting the players’ incentives to bid truthfully. Although this subsidized Vickrey auction is not allocatively efficient, it always Pareto dominates the conventional Vickrey auction and sometimes dominates other existing cost sharing mechanisms.
Elementary theory of heterojunctions

An LCAO theory of heterojunction band-edge discontinuities is formulated and tested for approximate self-consistency. It leads to a table of valence-band maxima for all tetrahedral semiconductors; discontinuities can be obtained from the table directly by subtraction. The discrepancies with the current scattered data do not appear significantly larger than the uncertainty in those data, a few tenths of electron volts. A pseudopotential theory of such discontinuities is also formulated, based upon self-consistent atomic pseudopotentials. This leads to valence-band maxima reasonably consistent with the LCAO theory, except for junctions between materials of significantly different bond length. It also suggests that the Frensley—Kroemer scheme does produce self-consistency for systems of matching lattice constant, but produces incorrect trends with mismatch in lattice constant. The goal in any case is taken to be a table of valence-band maxima. LCAO values seem a better standard than photoelectric thresholds, though a comparison of the two indicates them to be roughly consistent for treating junctions if both sides are homopolar or if both sides are polar.
Wealth Distribution and the Provision of Public Goods: Evidence from the United States

This paper examines the role of inequality in the provision of public goods. County level data from the U.S. in 1890 provides comparable units of analysis operating with similar property tax systems, ensuring that we do not empirically confuse differences in tax systems with differences in public goods provision. Climatic data is used as an instrument for land inequality to provide identification of the effect of inequality. The results indicate that land inequality caused significantly lower overall property tax rates. This effect is driven almost exclusively by the effect of land inequality on taxes related directly to schooling. In contrast, non-school funding was not significantly affected by inequality. While informative about the effect of land inequality on public goods provision, an examination of the details of the tax system suggests that these results should not necessarily be taken as a rejection of median voter predictions.
Mode-medium instability and its correction with a Gaussian-reflectivity mirror.

A high power CO2 laser beam is known to deteriorate after a few microseconds due to a mode-medium instability (MMI) which results from an intensity dependent heating rate related to the vibrational-to-translational decay of the upper and lower CO2 lasing levels. An iterative numerical technique is developed to model the time evolution of the beam as it is affected by the MMI. The technique is used to study the MMI in an unstable CO2 resonator with a hard-edge output mirror for different parameters like the Fresnel number and the gas density. The results show that the mode of the hard edge unstable resonator deteriorates because of the diffraction ripples in the mode. A Gaussian-reflectivity mirror was used to correct the MMI. This mirror produces a smoother intensity profile which significantly reduces the effects of the MMI. Quantitative results on peak density variation and beam quality are presented.
Stand-replacing patches within a ‘mixed severity’ fire regime: quantitative characterization using recent fires in a long-established natural fire area

The complexity inherent in variable, or mixed-severity fire regimes makes quantitative characterization of important fire regime attributes (e.g., proportion of landscape burned at different severities, size and distribution of stand-replacing patches) difficult. As a result, there is ambiguity associated with the term ‘mixed-severity’. We address this ambiguity through spatial analysis of two recent wildland fires in upper elevation mixed-conifer forests that occurred in an area with over 30 years of relatively freely-burning natural fires. We take advantage of robust estimates of fire severity and detailed spatial datasets to investigate patterns and controls on stand-replacing patches within these fires. Stand-replacing patches made up 15% of the total burned area between the two fires, which consisted of many small patches ( 60 ha). Smaller stand-replacing patches were generally associated with shrub-dominated (Arctostaphylos spp. and Ceanothus spp.) and pine-dominated vegetation types, while larger stand-replacing patches tended to occur in more shade-tolerant, fir-dominated types. Additionally, in shrub-dominated types stand-replacing patches were often constrained to the underlying patch of vegetation, which for the shrub type were smaller across the two fire areas than vegetation patches for all other dominant vegetation types. For white and red fir forest types we found little evidence of vegetation patch constraint on the extent of stand-replacing patches. The patch dynamics we identified can be used to inform management strategies for landscapes in similar forest types.
Testing Vietnam's public safety net

An effective public safety net can be important in a poor transition economy such as Vietnam. Yet we know very little about the performance of existing public transfers as a safety net. Using panel data, the paper investigates whether Vietnam's main social welfare transfers promoted poor people out of poverty and whether they protected the non-poor from becoming poor. It also explores the role transfer programs played in the country's dramatic reduction of poverty in the 1990s. Counterfactual consumption levels without transfers allow for behavioral responses. The findings suggest that transfer programs helped few people escape poverty and protected even fewer from falling into poverty. The public safety net appears to have been largely irrelevant to the country's recent poverty reduction record.
Trackability with Imprecise Localization

Imagine a tracking agent \(P()\) who wants to follow a moving target \( Q({})\) in \(d\)-dimensional Euclidean space. The tracker has access to a noisy location sensor that reports an estimate \(\tilde{Q}(t)\) of the target’s true location \( Q({t})\) at time \(t\), where \(|| Q({t}) - \tilde{Q}(t)||\) represents the sensor’s localization error. We study the limits of tracking performance under this kind of sensing imprecision. In particular, (1) what is \(P()\)’s best strategy to follow \( Q({})\) if both \(P()\) and \( Q({})\) can move with equal speed, (2) at what rate does the distance \(|| Q({t}) - P(t) ||\) grow under worst-case localization noise, (3) if \(P()\) wants to keep \( Q({})\) within a prescribed distance \(L\), how much faster does it need to move, and (4) what is the effect of obstacles on the tracking performance, etc. Under a relative error model of noise, we are able to prove upper and lower bounds for the worst-case tracking performance, both with or without obstacles. We also provide simulation results on real and synthetic data to illustrate trackability under imprecise localization.
Leaky mode vertical cavity lasers using cavity resonance modification

Singlemode operation of selectively oxidised monolithic vertical cavity laser diodes is demonstrated using optical antiguiding induced by cavity resonance modifications. A higher refractive index surrounding the laser cavity is accomplished by increasing the optical cavity length in this region to form leaky-mode lasers. The monolithic antiguiding lasers are fabricated using an etch and regrowth process of the top semiconductor distributed Bragg reflector mirror. The leaky-mode vertical cavity lasers exhibit single transverse mode operation up to injection currents greater than 13 times the threshold current.
Discovery of Malicious Attacks to Improve Mobile Collaborative Learning (MCL)

Mobile collaborative learning (MCL) is highly acknowledged and focusing paradigm in eductional institutions and several organizations across the world. It exhibits intellectual synergy of various combined minds to handle the problem and stimulate the social activity of mutual understanding. To improve and foster the baseline of MCL, several supporting architectures, frameworks including number of the mobile applications have been introduced. Limited research was reported that particularly focuses to enhance the security of those pardigms and provide secure MCL to users. The paper handles the issue of rogue DHCP server that affects and disrupts the network resources during the MCL. The rogue DHCP is unauthorized server that releases the incorrect IP address to users and sniffs the traffic illegally. The contribution specially provides the privacy to users and enhances the security aspects of mobile supported collaborative framework (MSCF). The paper introduces multi-frame signature-cum anomaly-based intrusion detection systems (MSAIDS) supported with novel algorithms through addition of new rules in IDS and mathematcal model. The major target of contribution is to detect the malicious attacks and blocks the illegal activities of rogue DHCP server. This innovative security mechanism reinforces the confidence of users, protects network from illicit intervention and restore the privacy of users. Finally, the paper validates the idea through simulation and compares the findings with other existing techniques. General Terms: Design , Development , Theory. Index Terms Client, DHCP server, rogue DHCP server, mobile learning environment, algorithms, signature-cum anomaly based Intrusion detection. Inclusion of IDS rules, sniffer, nikito, stick.
Metallation and mismetallation of iron and manganese proteins in vitro and in vivo: the class I ribonucleotide reductases as a case study

How cells ensure correct metallation of a given protein and whether a degree of promiscuity in metal binding has evolved are largely unanswered questions. In a classic case, iron- and manganese-dependent superoxide dismutases (SODs) catalyze the disproportionation of superoxide using highly similar protein scaffolds and nearly identical active sites. However, most of these enzymes are active with only one metal, although both metals can bind in vitro and in vivo. Iron(II) and manganese(II) bind weakly to most proteins and possess similar coordination preferences. Their distinct redox properties suggest that they are unlikely to be interchangeable in biological systems except when they function in Lewis acid catalytic roles, yet recent work suggests this is not always the case. This review summarizes the diversity of ways in which iron and manganese are substituted in similar or identical protein frameworks. As models, we discuss (1) enzymes, such as epimerases, thought to use FeII as a Lewis acid under normal growth conditions but which switch to MnII under oxidative stress; (2) extradiol dioxygenases, which have been found to use both FeII and MnII, the redox role of which in catalysis remains to be elucidated; (3) SODs, which use redox chemistry and are generally metal-specific; and (4) the class I ribonucleotide reductases (RNRs), which have evolved unique biosynthetic pathways to control metallation. The primary focus is the class Ib RNRs, which can catalyze formation of a stable radical on a tyrosine residue in their β2 subunits using either a di-iron or a recently characterized dimanganese cofactor. The physiological roles of enzymes that can switch between iron and manganese cofactors are discussed, as are insights obtained from the studies of many groups regarding iron and manganese homeostasis and the divergent and convergent strategies organisms use for control of protein metallation. We propose that, in many of the systems discussed, “discrimination” between metals is not performed by the protein itself, but it is instead determined by the environment in which the protein is expressed.
On Consensus Algorithms for Double-Integrator Dynamics

This note considers consensus algorithms for double-integrator dynamics. We propose and analyze consensus algorithms for double-integrator dynamics in four cases: 1) with a bounded control input, 2) without relative velocity measurements, 3) with a group reference velocity available to each team member, and 4) with a bounded control input when a group reference state is available to only a subset of the team. We show that consensus is reached asymptotically for the first two cases if the undirected interaction graph is connected. We further show that consensus is reached asymptotically for the third case if the directed interaction graph has a directed spanning tree and the gain for velocity matching with the group reference velocity is above a certain bound. We also show that consensus is reached asymptotically for the fourth case if and only if the group reference state flows directly or indirectly to all of the vehicles in the team.