cssi/SciSciGPT-SciSciNet huggingface dataset:
Near-IR Properties of Quasar Host Galaxies

We have obtained deep, near-IR images of nearly 100 host galaxies of nearby quasars and Seyferts. We find the near-IR light to be a good tracer of luminous mass in these galaxies. For the most luminous quasars there is a correlation between the maximum allowed B-band nuclear luminosity and the host galaxy mass, a “luminosity/host-mass limit”. Comparing our images with images from HST, we find that the hosts of these very luminous quasars are likely early type galaxies, even for radio-quiet objects whose lower-luminosity counterparts traditionally live in spirals. We speculate that the luminosity/host-mass limit represents a physical limit on the size of black hole that can exist in a given galaxy spheroid mass. We discuss the promises of NICMOS for detecting the hosts of luminous quasars.
The Current State and Future Direction of IT Audit: Challenges and Opportunities

ABSTRACT: Embracing the spirit of the Pathways Commission's focus of enhancing the value of practitioner/educator exchanges, the inaugural Journal of Information Systems Conference (JISC) brought together 30 academic researchers and 15 practitioners to discuss the current state and the future direction of information technology (IT) audit research and practice. Panelists, comprised of practitioners from government, public accounting, and industry, provided insight into current IT audit issues. The first panel discussed the role of IT auditors in helping organizations meet compliance requirements and ensuring that information systems add value to the organization. The second panel addressed the future of IT audit in a world of advanced analytics and emerging technologies. Although the panels addressed separate topics, common themes emerged from the discussions. Issues facing the IT audit profession as a result of the increasing volume of data available, coupled with changing technology and increasing regul...
Mod 2 representations of elliptic curves

This note gives explicit equations for the elliptic curves (in characteristic not 2 or 3) with mod 2 representation isomorphic to that of a given one.
Bayesian Decision Models in Health Care

The paper discusses how probability of rare events, for example, breach of patients' privacy, can be assessed from clues in the environment using Bayesian probability models. The paper shows how likelihood ratios associated with various clues in the environment could be assessed from interviews with panels of experts. Keywords: Bayesian; probability assessment; group process; health care; likelihood ratio assessment
Quantum Geometry and Black Holes

In his Ph.D. thesis, Bekenstein suggested that, for a black hole in equilibrium, a multiple of its surface gravity should be identified with its temperature and a multiple of the area of its event horizon should be identified with its thermodynamic entropy [1]. In this reasoning, he had to use not only general relativity but also quantum mechanics. Indeed, without recourse to the Planck’s constant, ℏ, the identification is impossible because even the physical dimensions do not match. Around the same time, Bardeen, Carter and Hawking derived laws governing the mechanics of black holes within classical general relativity [2]. These laws have a remarkable similarity with the fundamental laws of thermodynamics. However, the derivation makes no reference to quantum mechanics at all and, within classical general relativity, a relation between the two seems quite implausible: since nothing can come out of black holes and since their interiors are completely inaccessible to outside observers, it would seem that, physically, they can only have zero temperature and infinite entropy. Therefore the similarity was at first thought to be purely mathematical. This viewpoint changed dramatically with Hawking’s discovery of black hole evaporation in the following year [3]. Using an external potential approximation, in which the gravitational field is treated classically but matter fields are treated quantum mechanically, Hawking argued that black holes are not black after all! They radiate as if they are black bodies with a temperature equal to 1/27π times the surface gravity. One can therefore regard the similarity between the laws of black hole mechanics and those of thermodynamics as reflecting physical reality and argue that the entropy of a black hole is given by 1/4-th its area. Thus, Bekenstein’s insights turned out to be essentially correct (although the precise proportionality factors he had suggested were modified).
Normal art galleries: Wall in - all in

We introduce the notion of a normal gallery, a gallery in which any configuration of guards that visually covers the walls necessarily covers the entire gallery. We show that any star gallery is normal and any gallery with at most two reflex corners is normal. A polynomial time algorithm is provided deciding if, for a given gallery and a finite set of positions within the gallery, there exists a configuration of guards in some of these positions that visually covers the walls, but not the entire gallery.
Wage Determination and Strike Activity in Nigeria

This paper presents a model designed to study wage determination and strike activity in an economic and institutional environment different from those analysed in the strike literature. This model embodies the hypotheses that wages and prices are jointly determined, and that incomes policies significantly contribute to the increase in the frequency of strikes in Nigeria. The model analysed in this paper departs from most previous studies by examining wage determination in Nigeria, where collective bargaining co-exists with wage commissions appointed by the government. We develop a simultaneous equations model which enables us to explain the Nigerian strike experience from 1950 through 1989, and to examine the influence of the government on wage determination, price movements, and strike frequency. Using aggregate data for Nigeria, the estimated results show that changes in the price level, union density, and the wage policies of the government have positive and statistically significant influence on the incidence of strikes. The tests of causal relationships show that a bi-directional causal relationship exists between wages and prices, while wages, prices, and union density Granger-cause strikes.
An M component with a concurrent dart leader traveling along different paths during a lightning flash

Utilizing time-correlated high-speed video and electric field change data, a seven-stroke lightning flash is described in which the fifth return stroke (RS) occurs 0.80 ms after the fourth RS connects to a different ground location 3.3 km away. The fifth RS is 0.34 ms after an M component starts down the different channel. The fifth stroke involves a dart leader traveling concurrently, though slower than the M component, in a prior channel to ground. There was no indication of leader advance along this path earlier during the fourth RS. The fourth stroke involves a stepped leader that started from the end of an observed prior dart leader branch which did not previously propagate to ground. The concurrent M component and dart leader are preceded by an in-cloud event evidenced by a large-amplitude, fast electric field change pulse, at 6.1 km estimated altitude, inferred as the connection to the channel for the M component. The M component current apparently initiates the dart leader about 40 µs later. A visible channel length of 10,400 m allows for the 2-D propagation speed of the M component luminosity to be estimated in the range of 1.0 to 1.2 × 108 m s−1. The concurrent dart leader travels a visible length of 3445 m with 2-D speed of 1.7 × 107 m s−1, similar to other dart leaders in this flash. Luminosity evolution along the channel through the RS and M component is also described. Estimated optical risetimes of three separate M components are 80–200 µs at 520 m above ground.
Visualizing and Understanding Convolutional Networks

Large Convolutional Network models have recently demonstrated impressive classification performance on the ImageNet benchmark Krizhevsky et al. [18]. However there is no clear understanding of why they perform so well, or how they might be improved. In this paper we explore both issues. We introduce a novel visualization technique that gives insight into the function of intermediate feature layers and the operation of the classifier. Used in a diagnostic role, these visualizations allow us to find model architectures that outperform Krizhevsky et al on the ImageNet classification benchmark. We also perform an ablation study to discover the performance contribution from different model layers. We show our ImageNet model generalizes well to other datasets: when the softmax classifier is retrained, it convincingly beats the current state-of-the-art results on Caltech-101 and Caltech-256 datasets.
Mechanical Ventilation for Severe Asthma

Acute exacerbations of asthma can lead to respiratory failure requiring ventilatory assistance. Noninvasive ventilation may prevent the need for endotracheal intubation in selected patients. For patients who are intubated and undergo mechanical ventilation, a strategy that prioritizes avoidance of ventilator-related complications over correction of hypercapnia was first proposed 30 years ago and has become the preferred approach. Excessive pulmonary hyperinflation is a major cause of hypotension and barotrauma. An appreciation of the key determinants of hyperinflation is essential to rational ventilator management. Standard therapy for patients with asthma undergoing mechanical ventilation consists of inhaled bronchodilators, corticosteroids, and drugs used to facilitate controlled hypoventilation. Nonconventional interventions such as heliox, general anesthesia, bronchoscopy, and extracorporeal life support have also been advocated for patients with fulminant asthma but are rarely necessary. Immediate mortality for patients who are mechanically ventilated for acute severe asthma is very low and is often associated with out-of-hospital cardiorespiratory arrest before intubation. However, patients who have been intubated for severe asthma are at increased risk for death from subsequent exacerbations and must be managed accordingly in the outpatient setting.
Analysis of focused laser differential interferometry

A computational method for predicting the output of a focused laser differential interferometer (FLDI) given an arbitrary density field is presented. The method is verified against analytical predictions and experimental data. The FLDI simulation software is applied to the problem of measuring Mack-mode wave packets in a hypervelocity boundary layer on a 5° half-angle cone. The software is shown to complement experiments by providing the necessary information to allow quantitative density fluctuation magnitudes to be extracted from experimental measurements.
More growth or fewer collapses ? a new look at long run growth in Sub-Saharan Africa

Low and highly volatile growth define Africa's growth experience. But there is no evidence that growth volatility is associated to long term economic performance. This result may be misleading if it suggests that volatility is not important for economic and social progress. In this paper we use a variant of the method developed by Hausmann, Pritchett, and Rodrik (2005) to identify both growth acceleration and deceleration episodes in Africa between 1975 and 2005. The authors find that Africa has had numerous growth acceleration episodes in the last 30 years, but also nearly a comparable number of growth collapses, offsetting most of the benefits of growth. Had Africa avoided its growth collapses, it would have grown 1.7 percent a year instead of 0.7 percent, and its GDP per capita would have been more than 30 percent higher in 2005. The authors also find that growth accelerations and decelerations have an asymmetric impact on human development outcomes. Finally, our results suggest that it is easier to identify the likely institutional and policy origins of growth decelerations than of growth accelerations.
In Vivo Measurement of Blood‐Brain Barrier Permeability

This unit describes various protocols for the in vivo quantitation of drug permeability across the rodent blood-brain barrier. Methods for the measurement of drug influx and efflux are described, and support protocols are provided for determining intravascular capillary volume and cerebral perfusion flow. An in situ perfusion technique is also provided for assessing whether transport of a test compound occurs by carrier-mediated or saturable transport.
Termite mounds harness diurnal temperature oscillations for ventilation

Many species of millimetric fungus-harvesting termites collectively build uninhabited, massive mound structures enclosing a network of broad tunnels that protrude from the ground meters above their subterranean nests. It is widely accepted that the purpose of these mounds is to give the colony a controlled microclimate in which to raise fungus and brood by managing heat, humidity, and respiratory gas exchange. Although different hypotheses such as steady and fluctuating external wind and internal metabolic heating have been proposed for ventilating the mound, the absence of direct in situ measurement of internal air flows has precluded a definitive mechanism for this critical physiological function. By measuring diurnal variations in flow through the surface conduits of the mounds of the species Odontotermes obesus, we show that a simple combination of geometry, heterogeneous thermal mass, and porosity allows the mounds to use diurnal ambient temperature oscillations for ventilation. In particular, the thin outer flutelike conduits heat up rapidly during the day relative to the deeper chimneys, pushing air up the flutes and down the chimney in a closed convection cell, with the converse situation at night. These cyclic flows in the mound flush out CO2 from the nest and ventilate the colony, in an unusual example of deriving useful work from thermal oscillations.
On planar Cremona maps of prime order

This paper contains a new proof of the classification of prime order elements of $\Bir(\P^2)$ up to conjugation. The first results on this topic can be traced back to classic works by Bertini and Kantor, among others. The innovation introduced by this paper consists of explicit geometric constructions of these Cremona transformations and the parameterization of their conjugacy classes. The methods employed here are inspired to [4], and rely on the reduction of the problem to classifying prime order automorphisms of rational surfaces. This classification is completed by combining equivariant Mori theory to the analysis of the action on anticanonical rings, which leads to characterize the cases that occur by explicit equations (see [28] for a different approach). Analogous constructions in higher dimensions are also discussed.
Some recent progress on the complexity of lattice problems

We survey some recent developments in the study of the complexity of lattice problems. After a discussion of some problems on lattices which can be algorithmically solved efficiently, our main focus is the recent progress on complexity results of intractability. We discuss Ajtai's worst-case/average-case connections, NP-hardness and non-NP-hardness, transference theorems between primal and dual lattices, and the Ajtai-Dwork cryptosystem.
Role of Sox9 in Growth Factor Regulation of Articular Chondrocytes

Chondrogenic polypeptide growth factors influence articular chondrocyte functions that are required for articular cartilage repair. Sox9 is a transcription factor that regulates chondrogenesis, but its role in the growth factor regulation of chondrocyte proliferation and matrix synthesis is poorly understood. We tested the hypotheses that selected chondrogenic growth factors regulate sox9 gene expression and protein production by adult articular chondrocytes and that sox9 modulates the actions of these growth factors. To test these hypotheses, we delivered insulin-like growth factor-I (IGF-I), fibroblast growth factor-2 (FGF-2), bone morphogenetic protein-2 (BMP-2) and/or bone morphogenetic protein-7 (BMP-7), or their respective transgenes to adult bovine articular chondrocytes, and measured changes in sox9 gene expression and protein production. We then knocked down sox9 gene expression with sox9 siRNA, and measured changes in the expression of the genes encoding aggrecan and types I and II collagen, and in the production of glycosaminoglycan, collagen and DNA. We found that FGF-2 or the combination of IGF-I, BMP-2, and BMP-7 increased sox9 gene expression and protein production and that sox9 knockdown modulated growth factor actions in a complex fashion that differed both with growth factors and with chondrocyte function. The data suggest that sox9 mediates the stimulation of matrix production by the combined growth factors and the stimulation of chondrocyte proliferation by FGF-2. The mitogenic effect of the combined growth factors and the catabolic effect of FGF-2 appear to involve sox9-independent mechanisms. Control of these molecular mechanisms may contribute to the treatment of cartilage damage.
Consumer Protection Laws and Regulations in Deposit and Loan Services : A Cross-Country Analysis with a New Data Set

Consumer protection and financial literacy can contribute to improved efficiency, transparency, competition, and access in retail financial markets by reducing information asymmetries and power imbalances between providers and users of financial services. Financial consumer protection has gained significance in policy debates, especially since the onset of the financial crisis in 2008. This paper presents the results of a survey on consumer protection regulations in 142 countries. The findings indicate that although consumer protection legislation is in place in the majority of countries, these do not necessarily address the issues specific to financial services. There is some evidence that enforcement powers and monitoring capacity are limited in many countries, obstructing the effective implementation of the existing regulations. Furthermore, independent third party dispute resolution mechanisms are not widespread. The paper also compiles comprehensive information on laws and regulations relevant for consumer protection and discusses a number of challenges related to empirical analyses of financial consumer protection to enable cross-country comparison.
Asymmetric [3+2] Annulation Approach to 3‐Pyrrolines: Concise Total Syntheses of (−)‐Supinidine, (−)‐Isoretronecanol, and (+)‐Elacomine

An asymmetric [3+2] annulation reaction to form 3-pyrroline products is reported. Upon treatment with lithium diisopropylamide, readily available ethyl 4-bromocrotonate is deprotonated and trapped with Ellman imines selectively at the α-position to yield enantiopure 3-pyrroline products. This new method is compatible with aryl, alkyl, and vinyl imines. The efficacy of the method is showcased by short asymmetric total syntheses of (-)-supinidine, (-)-isoretronecanol, and (+)-elacomine. This novel annulation approach also works for an aldehyde, thus providing access to a 2,5-dihydrofuran product in a single step from simple precursors. By modifying the structure of the carbanion nucleophile, an asymmetric vinylogous aza-Darzens reaction can be realized.
Convolutional-Code-Specific CRC Code Design

Cyclic redundancy check (CRC) codes check if a codeword is correctly received. This paper presents an algorithm to design CRC codes that are optimized for the code-specific error behavior of a specified feedforward convolutional code. The algorithm utilizes two distinct approaches to computing undetected error probability of a CRC code used with a specific convolutional code. The first approach enumerates the error patterns of the convolutional code and tests if each of them is detectable. The second approach reduces complexity significantly by exploiting the equivalence of the undetected error probability to the frame error rate of an equivalent catastrophic convolutional code. The error events of the equivalent convolutional code are exactly the undetectable errors for the original concatenation of CRC and convolutional codes. This simplifies the computation because error patterns do not need to be individually checked for detectability. As an example, we optimize CRC codes for a commonly used 64-state convolutional code for information length ${k}=1024,$ demonstrating significant reduction in undetected error probability compared to the existing CRC codes with the same degrees. For a fixed target undetected error probability, the optimized CRC codes typically require 2 fewer bits.
Crowd-Funded Journalism

Crowd-funded journalism is a novel business model in which journalists rely on micropayments from ordinary people to finance their reporting. Based on analyses of the database of Spot.us, a pioneering crowd-funded journalism website, we examine the impact of crowd-funded journalism on the news produced. We apply a uses and gratifications approach to study consumers' choices when they donate to crowd-funded journalism and find that consumers are more likely to donate to stories that provide them with practical guidance for daily living e.g., stories about public health or local city infrastructure, as opposed to stories from which they gain a general awareness of the world e.g., cultural diversity, or government and politics. We discuss the implications for the future of news.
Relationships between putative G-quadruplex-forming sequences, RecQ helicases, and transcription

Putative G-quadruplex-forming sequences (PQS) have long been implicated in regulation of transcription, though the actual mechanisms are not well understood. One proposed mechanism involves the activity of PQS-specific helicases belonging to the RecQ helicase family. However, patterns of PQS that correlate with transcriptional sensitivity to RecQ helicases are not well studied, and no adequate transcriptional model exists to account for PQS effects. To better understand PQS transcriptional effects, we analyze PQS motifs in genes differentially-transcribed in Bloom Syndrome (BS) and Werner Syndrome (WS), two disorders resulting in loss of PQS-interacting RecQ helicases. We also correlate PQS genome-wide with transcription in multiple human cells lines while controlling for epigenetic status. Finally, we perform neural network clustering of PQS motifs to assess whether certain motifs are over-represented in genes sensitive to RecQ helicase loss. By analyzing PQS motifs in promoters of genes differentially-transcribed in BS and WS, we demonstrate that abundance of promoter PQS is generally higher in down-regulated genes and lower in up-regulated genes, and show that these effects are position-dependent. To interpret these correlations we determined genome-wide PQS correlations with transcription while controlling for epigenetic status. Our results identify multiple discrete transcription start site-proximal positions where PQS are correlated with either increased or decreased transcription. Finally, we report neural network clustering analysis of PQS motifs demonstrating that genes differentially-expressed in BS and WS are significantly biased in PQS motif composition. Our findings unveil unappreciated detail in the relationship between PQS, RecQ helicases, and transcription. We show that promoter PQS are generally correlated with reduced gene expression, and that this effect is relieved by RecQ helicases. We also show that PQS at certain positions on the downstream sense strand are correlated with increased transcription. We therefore propose a new transcriptional model in which promoter PQS have at least two distinct types of transcriptional regulatory effects.
Limitations of Markov chain Monte Carlo algorithms for Bayesian inference of phylogeny

Markov chain Monte Carlo algorithms play a key role in the Bayesian approach to phylogenetic inference. In this paper, we present the first theoretical work analyzing the rate of convergence of several Markov chains widely used in phylogenetic inference. We analyze simple, realistic examples where these Markov chains fail to converge quickly. In particular, the data studied are generated from a pair of trees, under a standard evolutionary model. We prove that many of the popular Markov chains take exponentially long to reach their stationary distribution. Our construction is pertinent since it is well known that phylogenetic trees for genes may differ within a single organism. Our results shed a cautionary light on phylogenetic analysis using Bayesian inference and highlight future directions for potential theoretical work.
Positive Stereotyping: The Cultural Relativist in the Classroom.

This paper examines the effect of the "cultural relativist" teacher on the performance of Indian students. Unlike the ethnocentric teacher who treats Indian students as deficient and inferior in intellectual, language, and social skills, the cultural relativist admires Indian culture and encourages Indian students to preserve their culture. Unfortunately, because of his or her patronizing attitude and insistence on a romanticized version of aboriginal life, the cultural relativist often is confronted with Indian students who are as silent and unresponsive as they are in the classes of the ethnocentric teacher. This paper analyzes the bases of this problem in teachers' misinterpretation of anthropological theory.
SYNTHESIS AND X-RAY CRYSTALLOGRAPHY OF CHIRAL TROPOCORONANDS

The synthesis of several chiral tropocoronands (6 and 7) has been accomplished. These compounds have been shown to complex with various metals. Tropocoronands that have been synthesized include H2(TC-3,cyhex) through H2(TC-6,cyhex) (6) and H2(TC-3,diphen) through H2(TC-6,diphen) (7). The route is short and the tropocoronands are easily purified by chromatography or recrystallization. Two other groups have been incorporated into tropocoronands, H2(TC-3,binap) (9) and H2(TC-6,pent) (10).
New Jacobi-type necessary and sufficient conditions for singular optimization problems

Jacobi-type conditions for singular optimization problems obtained by transformation to nonsingular form adaptable to linear quadratic optimal control theory
Global electric circuit implications of combined aircraft storm electric current measurements and satellite‐based diurnal lightning statistics

[1] We have combined analyses of high-altitude aircraft observations of electrified clouds with diurnal lightning statistics from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) that are carried aboard low-Earth-orbiting satellites to reproduce the diurnal variation in the global electric circuit. Using basic assumptions about the mean storm currents as a function of flash rate and location (i.e., land or ocean) and the global electric circuit, our estimate of the current in the global electric circuit matches the Carnegie curve diurnal variation to within 4% for all but two short periods of time, in which the difference was 11% in one time period (0430 UTC) and 6% in the second period (1830 UTC). This excellent agreement with the Carnegie curve was obtained without any tuning or adjustment of the satellite or aircraft data. We assume that (1) the mean values for current and flash rates in the aircraft storm overflight data set (1.7 A and 0.8 flashes min−1 for oceanic thunderstorms, 1.0 A and 2.2 flashes min−1 for land thunderstorms, 0.41 A for oceanic electrified shower clouds (i.e., electrified but no lightning detected), and 0.13 A for land electrified shower clouds) and (2) the diurnal variations in lightning rates over land and ocean found in the satellite data set are universally applicable. Mean contributions to the global electric circuit from land and ocean thunderstorms are 1.1 kA (land) and 0.7 kA (ocean). Contributions to the global electric circuit from electrified shower clouds are 0.22 kA for ocean storms and 0.04 kA for land storms. The mean total conduction current for the global electric circuit is 2.0 kA. The means that for the number of storms contributing to the global electric circuit, 1100 are land storms with lightning, 530 are ocean storms without lightning, 390 are ocean storms with lightning, and 330 are land storms without lightning. A closer fit to the Carnegie curve is possible if the contributions from electrified shower clouds are increased by a factor of 3 or 4.
Limited-Shift-Full-Rank Matrices With Applications in Asynchronous Cooperative Communications

Shift-full-rank (SFR) matrices are matrices that have full row rank no matter how their rows are shifted. SFR matrices have been used lately as generator matrices for a family of space-time trellis codes to achieve full diversity in asynchronous cooperative communications, where the numbers of columns of the SFR matrices correspond to the memory sizes of the trellis codes and an upper bound is assumed for all the possible delays during each packet (frame) transmission. In this paper, we study a variation of SFR matrices with relaxed conditions: limited-shift-full-rank (LT-SFR) matrices, i.e., the matrices that keep full row rank when the shifts of their rows are within some range called delay tolerance. As the generator matrices for the previously proposed space-time trellis codes, LT- SFR matrices can already guarantee asynchronous full diversity of the corresponding codes.
Two-layer thermal convection in miscible viscous fluids

The influence of a viscosity stratification on the interaction between thermal convection and a stable density discontinuity is studied, using laboratory experiments. Initially, two superposed isothermal layers of high-Prandtl-number miscible fluids are suddenly cooled from above and heated from below. By adjusting the concentrations of salt and cellulose, Rayleigh numbers between 300 and 3×107 were achieved for density contrasts between 0.45 % and 5 % and viscosity ratios between 1 and 6.4×104. Heat and mass transfer through the interface were monitored.Two-layer convection is observed but a steady state is never obtained since penetrative convection occurs. A new interfacial instability is reported, owing to the nonlinear interaction of the unstable thermal and stable chemical density gradients. As a result, the temperature condition at the interface is highly inhomogeneous, driving, on top of the classical small-scale thermal convection, a large-scale flow in each layer which produces cusps at the interface. Entrainment, driven by viscous coupling between the two layers, proceeds through those cusps. The pattern of entrainment is asymmetric: two-dimensional sheets are dragged into the more viscous layer, while three-dimensional conduits are produced in the less viscous layer. A simple entrainment model is proposed and scaling laws for the entrainment rate are derived; they explain the experimental data well.
Non-Fefferman-Graham asymptotics and holographic renormalization in new massive gravity

The asymptotic behavior of new massive gravity (NMG) is analyzed for all values of the mass parameter satisfying the Breitenlohner-Freedman bound. The traditional Fefferman-Graham expansion fails to capture the dynamics of NMG, and new terms in the asymptotic expansion are needed to include the massive graviton modes. New boundary conditions are discovered for a range of values −1 < 2m 2 l 2 < 1 at which non-Einstein modes decay more slowly than the Brown-Henneaux boundary conditions. The holographically renormalized stress tensor is computed for these modes, and the relevant counterterms are identified up to unphysical ambiguities.
CURRENT TOPICS IN ORGANIC MASS SPECTROMETRY

Abstract Although mass spectrometry is accepted as a key analytical tool for many molecular problems, the level of world-wide research activity in this field promises that these capabilities will continue to improve rapidly. Active research areas which will be discussed are liquid chromatography/mass spectrometry/computer systems applicable to complex mixtures of low volatility compounds, computer interpretation of unknown mass spectra, and collisional activation (CA) mass spectrometry. The latter can be viewed as a “double-resonance” technique, as a CA mass spectrum can be obtained of each peak in a normal mass spectrum. A variety of applications of CA/MS to ion and molecular structure determination and to the analysis of complex mixtures will be presented.
Zariski theorems and diagrams for braid groups

Empirical properties of generating systems for complex reflection groups and their braid groups have been observed by Orlik-Solomon and Broue-Malle-Rouquier, using Shephard-Todd classification. We give a general existence result for presentations of braid groups, which partially explains and generalizes the known empirical properties. Our approach is invariant-theoretic and does not use the classification. The two ingredients are Springer theory of regular elements and a Zariski-like theorem.
Non-perturbative Calculation of the Positronium Mass Spectrum in Basis Light-Front Quantization

We report on recent improvements to our non-perturbative calculation of the positronium spectrum. Our Hamiltonian is a two-body effective interaction which incorporates one-photon exchange terms, but neglects fermion self-energy effects. This effective Hamiltonian is diagonalized numerically in a harmonic oscillator basis at strong coupling (\({\alpha = 0.3}\)) to obtain the mass eigenvalues. We find that the mass spectrum compares favorably to the Bohr spectrum of non-relativistic quantum mechanics evaluated at this unphysical coupling.
A concise synthesis of (+)- and (−)-adociacetylene B

Abstract The synthesis of (−)-adociacetylene B was completed in six steps in a yield of 9.3%, while the (+)-enantiomer was synthesized in seven steps and 7.5%. An enzymatic resolution of racemic 1 using the lipase from Pseudomonas sp. was employed to obtain (+) and (−)- 1 . This synthesis of ( S , S )- 1 represents the first total synthesis of a naturally occurring acetylenic alcohol that has two chiral centers and four acetylene units.
Electron interaction and spin accumulation in spin polarized tunneling

We discuss the effect of electron interaction and spin accumulation on spin polarized tunneling. Charges of opposite magnitude are induced on opposite sides of the insulator. There is a splitting between the spin up and spin down bands which produces an additional contribution to the magnetoresistance. The ratio between the splitting and the current is an effective resistance, Rs. The difference between Rs on opposite sides of the junction is of the order of (much less than) the interfacial resistance when the magnetization of the ferromagnets are parallel (antiparallel) to each other. The signal to background ratio for the change in Rs between the parallel and the antiparallel configuration is much bigger than that for the resistance. This Rs (kΩ) is much larger in magnitude than that (≊10−5 Ω) observed in metallic trilayers and thus maybe of practical interest for applications.
Emerging internet‐enabled auction mechanisms in supply chain

Purpose – The purpose of this paper is to present the prevailing auction and bidding mechanisms in supply chain management. The paper aims to critically examine the implications of these auction mechanisms using the example of the transportation sector.Design/methodology/approach – A framework is presented to highlight the role of internet and information systems in the transportation sector. The paper discusses the complexities associated with embracing these internet‐enabled auction mechanisms and presents some research propositions.Findings – In its present state of affairs an electronic marketplace would become nothing but a virtual place where the competing firms would be indulged in price wars to maintain their presence. A prolonged spur of activities in this direction would lead to a stalemate where the winners are losers.Practical implications – In the long run it is important that the decisions associated with electronic auctions must be based on more than bargain‐basement price tags. The busines...
Asthma and Obesity in Adolescents: Is There an Association?

To determine if obesity is more prevalent in adolescents with asthma compared with nonasthmatic adolescents and to determine if obesity is associated with more severe asthma, we studied 265 adolescent asthmatics 12-21 years of age and 482 nonasthmatic adolescents. The prevalence of obesity in the asthmatic group was 20% compared to 17% in the control group. The prevalence of being at risk of overweight was similar for asthmatics (16%) and controls (15%). The prevalence of obesity in moderate to severe asthmatics (21%) was not different from prevalence of obesity in mild asthmatics (19%) or controls (17%). In this study of primarily African-American urban adolescents, obesity was not associated with asthma or more severe asthma.
Reciprocal relativity of noninertial frames: quantum mechanics

Noninertial transformations on time–position–momentum–energy space {t, q, p, e} with invariant Born–Green metric and the symplectic metric −de ∧ dt + dp ∧ dq are studied. This group of transformations contains the Lorentz group as the inertial special case and, in the limit of small forces and velocities, reduces to the expected Hamilton transformations leaving invariant the symplectic metric and the nonrelativistic line element ds2 = −dt2. The transformations bound relative velocities by c and relative forces by b. Spacetime is no longer an invariant subspace but is relative to noninertial observer frames. In the limit of b → ∞, spacetime is invariant. Born was lead to the metric by a concept of reciprocity between position and momentum degrees of freedom and for this reason we call this reciprocal relativity. For large b, such effects will almost certainly only manifest in a quantum regime. Wigner showed that special relativistic quantum mechanics follows from the projective representations of the inhomogeneous Lorentz group. Projective representations of a Lie group are equivalent to the unitary representations of its central extension. The same method of projective representations for the inhomogeneous group is used to define the quantum theory in the noninertial case. The central extension of the inhomogeneous group is the cover of the quaplectic group . is the Weyl–Heisenberg group. The group, and the associated Heisenberg commutation relations central to quantum mechanics, results directly from requiring projective representations. A set of second-order wave equations result from the representations of the Casimir operators.
Fast shared-memory algorithms for computing the minimum spanning forest of sparse graphs

Minimum spanning tree (MST) is one of the most studied combinatorial problems with practical applications in VLSI layout, wireless communication, and distributed networks, recent problems in biology and medicine such as cancer detection, medical imaging, and proteomics, and national security and bioterrorism such as detecting the spread of toxins through populations in the case of biological/chemical warfare. Most of the previous attempts for improving the speed of MST using parallel computing are too complicated to implement or perform well only on special graphs with regular structure. In this paper we design and implement four parallel MST algorithms (three variations of Borůvka plus our new approach) for arbitrary sparse graphs that for the first time give speedup when compared with the best sequential algorithm. In fact, our algorithms also solve the minimum spanning forest problem. We provide an experimental study of our algorithms on symmetric multiprocessors such as IBMs pSeries and Sun's Enterprise servers. Our new implementation achieves good speedups over a wide range of input graphs with regular and irregular structures, including the graphs used by previous parallel MST studies. For example, on an arbitrary random graph with 1M vertices and 20M edges, our new approach achieves a speedup of 5 using 8 processors. The source code for these algorithms is freely available from our web site.
Protocol for inexperienced Coasean bargainers confronting delay costs

Abstract Delay costs can affect the efficiency of the private resolution of environmental conflict between citizens who have minimal experience with Coasean-style bargaining. Using a laboratory experiment, this note examines whether two bargaining protocols — extensive form offers/counteroffers and cheap talk — can act as a substitute for bargaining experience. Our results suggest cheap talk was effective, but the extensive form protocol was not. Cheap talk reduced efficiency losses in two of three protocol designs by nearly 100 percentage points, an increase comparable to the gains achieved with experience.
K-medians, facility location, and the Chernoff-Wald bound

The paper gives approximation algorithms for the k-medians and facility-location problems (both NP-hard). For k-medians, the algorithm returns a solution using at most ln(n+n/epsilon)k medians and having cost at most (1+epsilon) times the cost of the best solution that uses at most k medians. Here epsilon > 0 is an input to the algorithm. In comparison, the best previous algorithm (Jyh-Han Lin and Jeff Vitter, 1992) had a (1+1/epsilon)ln(n) term instead of the ln(n+n/epsilon) term in the performance guarantee. For facility location, the algorithm returns a solution of cost at most d+ln(n) k, provided there exists a solution of cost d+k where d is the assignment cost and k is the facility cost. In comparison, the best previous algorithm (Dorit Hochbaum, 1982) returned a solution of cost at most ln(n)(d+k). For both problems, the algorithms currently provide the best performance guarantee known for the general (non-metric) problems. The paper also introduces a new probabilistic bound (called "Chernoff-Wald bound") for bounding the expectation of the maximum of a collection of sums of random variables, when each sum contains a random number of terms. The bound is used to analyze the randomized rounding scheme that underlies the algorithms.
Photosensing Arrays with Improved Spatial Resolution

The spatial resolution obtainable in a photosensing array used for optical imaging may be limited by the diffusion of photogenerated carriers within a uniformly doped semiconductor even if other components of the optical system are optimized and scattered light is reduced. A technique has been developed to improve the spatial resolution for critical applications by incorporating subsurface electric fields that accelerate the photogenerated carriers toward or away from the surface so that the carriers are prevented from diffusing to distant photosensing elements. The subsurface fields are obtained by incorporating suitable dopant concentration gradients into the structure. In one structure fabricated the subsurface field was formed by using a heavily doped buried layer and a lightly doped epitaxial film over a lightly doped substrate, all of the same conductivity type. This structure is compatible with the incorporation of other semiconductor devices in the same monolithic substrate. The technique has been applied to an array of photodiodes in a silicon integrated circuit, but the principle is directly applicable to other types of photosensing arrays, such as charge-coupled devices (CCD's), and other semiconductor materials.
Ext^1-quivers for the Witt algebra W(1,1)

Let g be the finite-dimensional Witt algebra W(1,1) over an algebraically closed field of characteristic p>3. It is well known that all simple W(1,1)-modules are finite-dimensional. Each simple module admits a character χ∈g∗. Given χ∈g∗ one can form the (finite-dimensional) reduced enveloping algebra u(g,χ). The simple modules for u(g,χ) are precisely those simple W(1,1)-modules admitting the character χ. In this paper the authors compute Ext1 between pairs of simple modules for u(g,χ).
Wave interactions in swept-wing flows

The leading-edge region of swept wings is dominated by the crossflow instability, resulting in vortices that all rotate in the same sense. The effect of these vortices on the behavior of other disturbances is examined and an interaction between these and disturbances of half the dominating crossflow wavelength is predicted. According to theory, the interaction is of crossflow-crossflow type. The effect explains the anomalies found in the experimental observations of Saric and Yeates (1985). Visually Saric and Yeates observe vortices at the wavelength predicted by linear theory; however, in their hot-wire measurements they find that the second harmonic dominates disturbance growth, with eventually three times the amplitude of the primary wave. In this case, the usual transition-prediction methods would fail, clearly indicating the importance of studying interactions of this sort.
Experiments on the development of the ear of Amblystoma punctatum

A series of experiments was performed during the years 1922-1925 on embryos of Amblystoma punctatum. Two main lines of investigation were carried out, namely, experiments to determine the limits of the regenerative capacity of the tissue surrounding the normal ear region, and experiments regarding the nature of the developing ear itself.The first group involved extirpation of ectoderm in the ear region of embryos at different stages of development. The size of the pieces removed was 0.2 mm., 0.3 mm., 0.4 mm., 0.5 mm., and 0.6 mm., respectively. It was found that complete regeneration generally followed when the operation was performed on stages earlier than that in which invagination of the ectoderm had occurred. Regeneration was completely checked only by the removal of a piece of ectoderm 0.6 mm. in diameter, after a distinct auditory plate had formed.A definite loss in the regenerative capacity of the surrounding ectoderm was evident, following invagination of the ear. The regenerated labyrinths were g...
Symplectic rigidity for Anosov hypersurfaces

We show, using standard results in length spectrum rigidity and symplectic homology, that if the unit tangent bundles of two compact surfaces of negative curvature are exact symplectomorphic, then the underlying surfaces are isometric, and hence the disk bundles are symplectomorphic smoothly up to the boundaries. Motivated by the work of Eliashberg and Hofer on unseen symplectic boundaries, we try to extend the above result to other classes of domains in (co)tangent bundles of surfaces. The domains we can treat consist of those bounded by deformations of negatively curved unit cotangent bundles through boundaries with Anosov characteristic (Reeb) flows. We show that if two such are exact symplectomorphic, then the two domains are symplectomorphic by a diffeomorphism smooth up to the boundary. Furthermore, if two such surfaces have the same marked length spectrum then they are connected by a 1-parameter family of domains bounded by hypersurfaces with smoothly time preserving conjugate Reeb flows by a smooth family of Hamiltonian diffeomorphisms. A few counterexamples to easy generalizations are given.