cssi/SciSciGPT-SciSciNet huggingface dataset:
Utilizing moment invariants and Grobner bases to reason about shapes

Shapes such as triangles or rectangles can be defined in terms of geometric properties invariant under a group of transformations. Complex shapes can be described by logic formulas with simpler shapes as the atoms. A standard technique for computing invariant properties of simple shapes is the method of moment invariants, known since the early 1960s. We generalize this technique to shapes described by arbitrary monotone formulas (formulas in propositional logic without negation). Our technique produces a reduced Grobner basisfor approximate shape descriptions. We show how to use this representation to solve decision problems related to shapes. Examples include determining if a figure has a particular shape, if one description of a shape is more general than another, and whether a specific geometric property is really necessary for specifying a shape. Unlike geometry theorem proving, our approach does not require the shapes to be explicitly defined. Instead, logic formulas combined with measurements performed on actual shape instances are used to compute well-characterized least squares approximations to the shapes. Our results provide a proof that decision problems stated in terms of these approximations can be solved in a finite number of steps.
Fairness, search frictions, and offshoring

Abstract: Fairness considerations are introduced into the determination of wages in a two factor Pissarides-style model of search unemployment to study its implications for the unemployment rates of unskilled and skilled workers in both the closed economy case and when the economy can offshore some inputs. Both fairness concerns and offshoring of jobs done by unskilled workers create the overhiring effect for skilled workers. An increase in the concern for fairness in the closed economy increases the cost of hiring unskilled workers and increases the unemployment rates of both types of workers; however, wage inequality decreases. In the open economy case, an increase in the concern for fairness leads to greater offshoring which prevents skilled unemployment from increasing, but the unemployment of unskilled workers increases. A reduction in the cost of offshoring also increases offshoring and increases the unemployment of unskilled workers, but has a positive effect on skilled workers. Due to the presence of an overhiring effect in the hiring of skilled workers for both offshoring and non-offshoring firms, skilled workers experience higher wages and lower unemployment. The opposite movements in skilled and unskilled unemployment render the net effect ambiguous. Even though wage inequality increases, the impact on the wages of unskilled workers is ambiguous.
New methods for preparing N,N-dialkyltrifluoroacetamides

The customary preparative methods for N,N-dialkyltrifluoroacetamides involve the acylation of an amine by trifluoroacetic acid or its derivatives. In this report the synthesis of N,N-dialkyltrifluoroacetamides by reacting trifluoroacetic anhydride or acid with disubstituted formamides and acetamides is discussed. These reactions are interpreted with the aid of gas chromatographic analysis. Different reaction mechanisms are proposed for the reactions of formamides and acetamides with trifluoroacetic anhydride or acid. The use of the proposed reaction mechanisms for the synthesis of other fluorinated compounds is discussed.
Photoinduced Coupling of Acetylenes and Quinone in the Solid State as Preorganized Donor-Acceptor Pairs.

Crystalline electron donor−acceptor (EDA) complexes of various diarylacetylenes (DA) and dichlorobenzoquinone (DB) are isolated and structurally characterized by X-ray crystallography. Deliberate e...
ADOLESCENT DRUG USERS: THE JUSTICE SYSTEM IS MISSING AN IMPORTANT OPPORTUNITY

A significant number of youth and young adults who use drugs have fallen through the cracks of our juvenile and adult justice systems in terms of receiving any meaningful services. The situation is due to a number of factors, including the reliance on adolescent self reporting utilized by most of the research, the failure of justice and other systems to routinely assess youth for either current drug use or indicia of drug use (e.g., “resiliency” or “protective” factors), and confidentiality and other restrictions pertaining to access to juvenile justice system information. Yet, retrospective reviews of drug use patterns for adults in the criminal justice system make it clear that drug use is beginning for most of these offenders during adolescence or before. This article urges (1) juvenile courts to develop mechanisms for systematically screening youth who come into the system for drug use and/or propensities for drug use and (2) adult courts to embark on similar strategies and to develop adolescent tracks that would be geared to providing the services these youth (despite their chronological age) need and would otherwise not receive in the adult system.
Infrared and raman spectra, vibrational assignment, and conformational stability of methacryloyl bromide

Abstract The IR (3500 to 20 cm −1 ) and Raman (3200 to 10 cm −1 ) spectra have been recorded for gaseous and solid methacryloyl bromide, CH 2 C(CH 3 )C(O)Br. Additionally, the Raman spectra of the liquid has been recorded and qualitative depolarization values have been obtained. These data have been interpreted on the basis that the s- trans conformer (the two double bonds are oriented trans to one another) is the thermodynamically preferred rotamer in the gaseous and liquid phases and the only rotamer present in the spectra of the annealed solid. A second high energy conformer is present in the fluid phases at ambient temperature and spectral features are consistent with it being the gauche conformer but the possibility that it is the s- cis conformer cannot be completely eliminated. From a temperature study of the Raman spectrum of the liquid an enthalpy difference of 326±12 cm −1 (932±34 cal mol −1 ) has been determined. The methyl and asymmetric torsional modes for the s- trans conformer have been assigned at 166.6 and 48 cm −1 , respectively, from the IR spectrum of the vapor. The threefold barrier to internal rotation of the methyl group has been calculated to be 662±2 cm −1 (1.89 kcal mol −1 ). A complete vibrational assignment is proposed based on IR band contours, depolarization values and group frequencies. These results are compared to similar quantities in some related molecules.
Maternal transmission of acquired immune deficiency syndrome

Acquired immune deficiency syndrome (AIDS) has been reported in previously healthy homosexual or bisexual males intravenous drug users heterosexual men with hemophilia and Haitians. The finding of heterosexual hemophiliacs with AIDS has raised the possibility of a transmittable blood-borne agent as a cause of this disease. The authors have found 3 female half-siblings who had clinical and laboratory evidence for AIDS. All 3 had evidence of abnormal in vitro cellular immunity; 2 had chronic active Epstein-Barr virus infection and lymphadenopathy; all 3 had chronic cutaneous Candida sp infection; and 2 had Pneumocystis carinii pneumonia. Their mother is a prostitute/drug addict with abnormal T-cell immunity including clinical and laboratory findings of mucocutaneous candidiasis. Histocompatibility typing is consistent with the history of different fathers for each child. Immunologic studies in 1 child evaluated prospectively from birth were abnormal by 2 months of age. These findings and the clinical histories indicate AIDS and strongly suggest vertical transmission of an agent(s) during the perinatal period. (authors)
Larvae from deep-sea methane seeps disperse in surface waters

Many species endemic to deep-sea methane seeps have broad geographical distributions, suggesting that they produce larvae with at least episodic long-distance dispersal. Cold-seep communities on both sides of the Atlantic share species or species complexes, yet larval dispersal across the Atlantic is expected to take prohibitively long at adult depths. Here, we provide direct evidence that the long-lived larvae of two cold-seep molluscs migrate hundreds of metres above the ocean floor, allowing them to take advantage of faster surface currents that may facilitate long-distance dispersal. We collected larvae of the ubiquitous seep mussel “Bathymodiolus” childressi and an associated gastropod, Bathynerita naticoidea , using remote-control plankton nets towed in the euphotic zone of the Gulf of Mexico. The timing of collections suggested that the larvae might disperse in the water column for more than a year, where they feed and grow to more than triple their original sizes. Ontogenetic vertical migration during a long larval life suggests teleplanic dispersal, a plausible explanation for the amphi-Atlantic distribution of “B.” mauritanicus and the broad western Atlantic distribution of B. naticoidea . These are the first empirical data to demonstrate a biological mechanism that might explain the genetic similarities between eastern and western Atlantic seep fauna.
Patience or Fairness? Analyzing Social Preferences in Repeated Games

This paper investigates how the introduction of social preferences affects players' equilibrium behavior in both the one-shot and the infinitely repeated version of the Prisoner's Dilemma game. We show that fairness concerns operate as a "substitute" for time discounting in the infinitely repeated game, as fairness helps sustain cooperation for lower discount factors. In addition, such cooperation can be supported under larger parameter values if players are informed about each others' social preferences than if they are uninformed. Finally, our results help to identify conditions under which cooperative behavior observed in recent experimental repeated games can be rationalized using time preferences alone (patience) or a combination of time and social preferences (fairness).
Selectivity in ring-opening metatheses

Abstract The development of new olefin metathesis catalysts has allowed for the introduction of unique synthetic transformations. In this regard, ring-opening metathesis (ROM) offers a novel means of constructing diene-containing systems. The factors behind the chemo-, regio- and stereoselectivities of ROM are examined. The mechanistic models suggested are supported by stoichiometric studies of the unique ruthenium alkylidenes formed during the ROM of various cyclobutene-containing substrates.
Yttrium polyoxometalates. Synthesis and characterization of a carbonate-encapsulated sandwich-type complex.

Reaction of A-α-PW9O349- with YCl3 in an aqueous Na2CO3 solution produces a dianion-encapsulated A-type sandwich polyoxometalate, (YOH2)3(CO3)(A-α-PW9O34)211-. The X-ray structure of this complex reveals that three Y(III) ions are sandwiched between two A-α-PW9O349- moieties and that a carbonate dianion is encapsulated in the same plane as the three Y(III) atoms. The oxygen atoms of the CO32- are sitting at the midpoints of the sides of the triangle formed by the three Y(III) ions. 31P and 13C NMR studies confirm that this complex is significantly more stable than the analogous A-type sandwich polyoxometalates containing divalent metals.
Determining Cosmic Microwave Background Anisotropies in the Presence of Foregrounds

Separating foregrounds from the signal is one of the major challenges in cosmic microwave back- ground (CMB) experiments. A simple way to estimate the CMB temperature in a given pixel is to -t for the amplitudes of the CMB and the various foreground components. The variance squared of this esti- mator is shown to be equal to (FDF)2 where is the variance in the absence of fore- p h2 ) p shape , p h grounds, is the variance due to the uncertainty in the shapes of the foreground components, and p shape FDF is the foreground degradation factor. This one number, the FDF, gives a good indication of the ability of a given experiment to disentangle the CMB from foreground sources. A variety of applications relating to the planning and analyzing of experiments is presented. This approach, viz., analyzing the variance, can be used to assess the usefulness of any estimator. Subject headings: cosmic microwave background E cosmology: observations E methods: statistical
Inferring domain-domain interactions from protein-protein interactions

Protein-protein interactions are important events in cellular and biochemical processes within a cell. Several researchers have undertaken the task of analyzing protein-protein interactions covering all genes of an organism by using yeast two-hybrid assays. Protein-protein interactions involve physical interactions between protein domains. Therefore, understanding protein interactions at the domain level gives a global view of the protein interaction network, and possibly extends functions of proteins. In this study, we present a Maximum Likelihood approach to infer domain-domain interactions from the 5719 yeast protein-protein interactions obtained in the high throughput two-hybrid experiments by Uetz et al., 2000 and Ito et al., 2001. The accuracies of our predictions are measured at the protein level. Our study includes the following three results: (1) using the inferred domain-domain interactions, we predict interactions between proteins and achieve 39.0% specificity and 79.7% sensitivity; (2) our predicted protein-protein interactions have a significant overlap with the MIPS(http://mips.gfs.de) protein-protein interactions obtained by methods other than the two-hybrid systems; and (3) the mean correlation coefficient of the gene expression profiles for our predicted interacting pairs is significantly higher than that for random pairs as well as that of interacting pairs in Uetz's and Ito's experimental data. Our method has shown robustness in analyzing incomplete data sets and dealing with various experimental errors. We find several novel protein-protein interactions such as RPS0A interacting with APG17 and TAF40 interacting with SPT3, which are consistent with the functions of the proteins.
Application of Silicon Carbide Photodiode Flame Temperature Sensors in an Active Combustion Pattern Factor Control System

This paper describes the development and initial application studies for an active combustion pattern factor controller (APFC) for gas turbines. The system is based around the use of a novel silicon carbide optical ultraviolet dual diode flame temperature sensor (FTS) developed by General Electric Co. The APFC system determines combustion flame temperatures, validates the values, and integrates an assessment of signal and combustion hardware health to determine how to trim the fuel flow to individual fuel nozzles. Key aspects of the system include the following: determination of each flame's bulk temperature using the FTS, assessment of the reliability of the flame temperature data and physical combustion hardware health through analysis of the high-frequency output of the sensor, validation of the flame temperature signal using a data-driven approach, fusion of sensor "health indices" into the APFC to alter the trim control signal based on the health (or "believability") of each sensor and fuel nozzle/combustor, fault-tolerant peak/valley detection and control module that selects individual fuel valves to target for reducing pattern factor while simultaneously balancing the overall fuel flow. The authors demonstrated feasibility of the approach by performing simulations using a quasi-2D T700 turbine engine model. Tests were run on the simulated platform with no faults, simulated sensor faults, and on a system with underlying combustion hardware issues. The final APFC system would be applicable for aviation, naval, and land-based commercial gas turbines, and can be used in closed-loop control or adapted as an open-loop advisory/ diagnostic system.
Active control of unsteady combustion-induced oscillations

A loudspeaker-based active control system has been used to study a longitudinal combustion instability mode and its active control in a small scale premixed combustor. A simple gain/phase-shift type controller is shown to successfully suppress oscillations in the combustor at all equivalence ratios at low flow rates. It is found, however, that as the flow rate through the combustor is increased, the performance of the controller deteriorates rapidly, both in terms of allowable gain and phase margin and reduced effect on dominant instability such that beyond certain flow rates the controller is unable to suppress the oscillations for any values of gain and phaseshift. Nyquist stability diagram obtained from the frequency response data are used to understand the performance of the controller and help design an advanced controller with somewhat improved performance. The physical model developed by Lang et al. is adapted to help understand important features of the combustion instability and its active control. Without the controller the model is found to predict the frequency of the dominant instability mode and its variation with equivalence ratio fairly well. For off-stoichiometric operation the model predicts an increase in the number of potential instability modes as is also observed in the measured power spectra. With the controller "on," the model shows that the controller interacts significantly with the combustion and in one case examined here, it is shown that the controller stabilizes the second longitudinal mode for one value of gain but at just a slightly higher value renders the previously stable third mode unstable. This offers plausible physical explanation for the observed limited gain and phase margin and the limited effectiveness of the controller at the higher flow rates. The model also predicts the stability boundary to have a reduced phase margin as observed experimentally.
Rank 72 high minimum norm lattices

Abstract Given a polarization of an even unimodular lattice and integer k ⩾ 1 , we define a family of unimodular lattices L ( M , N , k ) . Of special interest are certain L ( M , N , 3 ) of rank 72. Their minimum norms lie in { 4 , 6 , 8 } . Norms 4 and 6 do occur. Consequently, 6 becomes the highest known minimum norm for rank 72 even unimodular lattices. We discuss how norm 8 might occur for such a L ( M , N , 3 ) . Our method constructs such L ( M , N , k ) in dimensions 96, 120 and 128 with minimum norms 8.
Face recognition using 3D facial shape and color map information: comparison and combination

In this paper, we investigate the use of 3D surface geometry for face recognition and compare it to one based on color map information. The 3D surface and color map data are from the CAESAR anthropometric database. We find that the recognition performance is not very different between 3D surface and color map information using a principal component analysis algorithm. We also discuss the different techniques for the combination of the 3D surface and color map information for multi-modal recognition by using different fusion approaches and show that there is significant improvement in results. The effectiveness of various techniques is compared and evaluated on a dataset with 200 subjects in two different positions.
High-Nuclearity Sulfide-Rich Molybdenum−Iron−Sulfur Clusters: Reevaluation and Extension

High-nuclearity Mo-Fe-S clusters are of interest as potential synthetic precursors to the MoFe7S9 cofactor cluster of nitrogenase. In this context, the synthesis and properties of previously reported but sparsely described trinuclear ((edt)2M2FeS6) 3- (M ) Mo (2 ), W( 3)) and hexanuclear ((edt)2Mo2Fe4S9) 4- (4, edt ) ethane-1,2-dithiolate; Zhang, Z.; et al. Kexue Tongbao 1987, 32, 1405) have been reexamined and extended. More accurate structures of 2-4 that confirm earlier findings have been determined. Detailed preparations (not previously available) are given for 2 and 3, whose structures exhibit the C2 arrangement {((edt)M(S)(I2-S)2)2Fe III } 3- with square pyramidal Mo(V) and tetrahedral Fe(III). Oxidation states follow from 57 Fe Mossbauer parameters and an S ) 3 /2 ground state from the EPR spectrum. The assembly system 2/3FeCl3/3Li2S/nNaSEt in methanol/acetonitrile (n ) 4) affords (R4N)4(4) (R ) Et, Bu; 70-80%). The structure of 4 contains the (Mo2Fe4(I2-S)6(I3-S)2(I4-S)) 0 core, with the same bridging pattern as the (Fe6S9) 2- core of (Fe6S9(SR)2) 4- (1), in overall C2v symmetry. Cluster 4 supports a reversible three- member electron transfer series 4-/3-/2- with E1/2 ) -0.76 and - 0.30 Vi n Me 2SO. Oxidation of (Et4N)4(4) in DMF with 1 equiv of tropylium ion gives ((edt)2Mo2Fe4S9) 3- (5) isolated as (Et4N)3(5)‚2DMF (75%). Alternatively, the assembly system (n ) 3) gives the oxidized cluster directly as (Bu4N)3(5) (53%). Treatment of 5 with 1 equiv of (Cp2Fe) 1+ in DMF did not result in one-electron oxidation but instead produced heptanuclear ((edt)2Mo2Fe5S11) 3- (6), isolated as the Bu4N + salt (38%). Cluster 6 features the previously unknown core Mo2Fe5(I2-S)7(I3-S)4 in molecular C2 symmetry. In 4-6, the (edt)MoS3 sites are distorted trigonal bipramidal and the FeS4 sites are distorted tetrahedral with all sulfide ligands bridging. Mossbauer spectroscopic data for 2 and 4-6 are reported; (mean) iron oxidation states increase in the order 4 < 5 1 < 6 2. Redox and spectroscopic data attributed earlier to clusters 2 and 4 are largely in disagreement with those determined in this work. The only iron and molybdenum-iron clusters with the same sulfide content as the iron-molybdenum cofactor of nitrogenase are (Fe6S9(SR)2) 4- and ((edt)2Mo2Fe4S9) 3-,4- .
Reanalysis of the EMC charm production data with extrinsic and intrinsic charm at NLO

Abstract A calculation of the next-to-leading order exclusive extrinsic charm quark differential distributions in deeply inelastic electroproduction has recently been completed. Using these results we compare the NLO extrinsic contributions to the charm structure function F 2 ( x , Q 2 , m 2 c ) with the corresponding NLO intrinsic contributions. The results of this analysis are compared with the EMC DIS charm quark data and evidence for an intrinsic charm component in the proton is found.
Studies on the hydrocarboxylation of N-acetylimines, enamines and allylamines.

Abstract Treatment of an amide with an aldehyde in the presence of CO2(CO)8/CO/H2 results in N -acyl- α -amino acids. The scope and limitations of this reaction are explored.
Relating quarkonium wave functions at the origin

Abstract Within the context of nonrelativistic potential models, we obtain several formulas (with varying degrees of rigor) relating the wave functions at the origin of the c c , b c and b b S-wave quarkonium systems. One of our main results is a model-independent relation which seems to hold to within 3% for any reasonable choice of interquark potential and any choice of radial quantum number — namely, |Ψ b c (0)| 2 ⋍ |Ψ c c (0)| 1.3 |Ψ b b (0)| 0.7 (the exponents are motivated in the text). One of the physical consequences of this result is the following relationship between heavy meson masses which we expect to hold at about the 10% level: M B c ∗ − M B c ⋍ (0.7) (M J ψ − M η c ) 0.65 (Mγ − M ηb ) 0.35 .
International aid and financial crises in donor countries

The global financial crisis has already led to sharp downturns in the developing world. In the past, international aid has been able to offset partially the effects of crises that began in the developing world, but because this crisis began in the wealthy countries, donors may be less willing or able to increase aid in this crisis. Not only have donor-country incomes fallen, but the cause of the drop -- the banking and financial-sector crisis -- may exacerbate the effect on aid flows because of its heavy fiscal costs. This paper estimates how donor-country banking crises have affected aid flows in the past, using panel data from 24 donor countries between 1977 and 2007. The analysis finds that banking crises in donor countries are associated with a substantial additional fall in aid flows, beyond any income-related effects, perhaps because of the high fiscal costs of crisis and the debt hangover in the post-crisis periods. In most specifications, aid flows from crisis-affected countries fall by an average of 20 to 25 percent (relative to the counterfactual) and bottom out only about a decade after the banking crisis hits. In addition, the results confirm that donor-country incomes are robustly related to per-capita aid flows, with an elasticity of about 3. Because all donor countries are being hit hard by the current global recession, and several have also suffered banking-sector crises, there are reasons to expect that aid could fall by a significant amount (again, relative to the counterfactual) in the coming years -- just when aid may be most clearly justified to help smooth exogenous shocks to developing countries.
DOMAIN NUMBER DISTRIBUTION IN THE NONEQUILIBRIUM ISING MODEL

We study domain distributions in the one-dimensional Ising model subject to zero-temperature Glauber and Kawasaki dynamics. The survival probability of a domain, S(t)∼t−ψ, and an unreacted domain, Q1(t)∼t−δ, are characterized by two independent nontrivial exponents. We develop an independent interval approximation that provides close estimates for many characteristics of the domain length and number distributions including the scaling exponents.
Mixed operators in compressed sensing

Applications of compressed sensing motivate the possibility of using different operators to encode and decode a signal of interest. Since it is clear that the operators cannot be too different, we can view the discrepancy between the two matrices as a perturbation. The stability of l 1 -minimization and greedy algorithms to recover the signal in the presence of additive noise is by now well-known. Recently however, work has been done to analyze these methods with noise in the measurement matrix, which generates a multiplicative noise term. This new framework of generalized perturbations (i.e., both additive and multiplicative noise) extends the prior work on stable signal recovery from incomplete and inaccurate measurements of Candes, Romberg and Tao using Basis Pursuit (BP), and of Needell and Tropp using Compressive Sampling Matching Pursuit (CoSaMP). We show, under reasonable assumptions, that the stability of the reconstructed signal by both BP and CoSaMP is limited by the noise level in the observation. Our analysis extends easily to arbitrary greedy methods.
Software design validation tool

DECA is a computer program which is used in conjunction with a top-down dominated design methodology. The program organizes, validates, and produces a document depicting the design of a software system. The use of DECA significantly enhances the quality of the software design. The quality of the design in turn significantly benefits the quality of the implemented software system.
Recognition, prediction, and planning for assisted teleoperation of freeform tasks

The approach of inferring user's intended task and optimizing low-level robot motions has promise for making robot teleoperation interfaces more intuitive and responsive. But most existing methods assume a finite set of candidate tasks, which limits a robot's functionality. This paper proposes the notion of freeform tasks that encode an infinite number of possible goals (e.g., desired target positions) within a finite set of types (e.g., reach, orient, pick up). It also presents two technical contributions to help make freeform UIs possible. First, an intent predictor estimates the user's desired task, and accepts freeform tasks that include both discrete types and continuous parameters. Second, a cooperative motion planner continuously updates the robot's trajectories to achieve the inferred tasks by repeatedly solving optimal control problems. The planner is designed to respond interactively to changes in the indicated task, avoid collisions in cluttered environments, handle time-varying objective functions, and achieve high-quality motions using a hybrid of numerical and sampling-based techniques. The system is applied to the problem of controlling a 6D robot manipulator using 2D mouse input in the context of two tasks: static target reaching and dynamic trajectory tracking. Simulations suggest that it enables the robot to reach intended targets faster and to track intended trajectories more closely than comparable techniques.
Nonintrusive methods for monitoring the operational readiness of solenoid-operated valves.

Abstract Solenoid-operated valves (SOVs) are being studied at Oak Ridge National Laboratory as part of the USNRC Nuclear Plant Aging Research (NPAR) Program. The primary of the study is to identify, evaluate, and recommend methods for inspection, surveillance, monitoring and maintenance of SOVs that can ensure their operational readiness — that is, their ability to perform required safety functions under all anticipated operating conditions. An earlier (Phase 1) study described SOV failure modes and causes and identified measurable parameters that might be used to monitor the various degradations that lead to functional failure. The present (Phase II) study focuses on devising and then demonstrating the effectiveness of techniques and/or equipment with which to measure the previously identified performance paramaters (or others) and thus detect and ascertain the trend of the progress of any degradation that may be occuring. Several nonintrusive techniques are presently under investigation. These include monitoring coil mean temperature during operation by means of DC coil resistance, monitoring valve position by means of coil AC impedance, verifying free SOV plunger movement by measuring current and volatage at their critical bistable (pickup/dropout) values, and detecting the presence of shorted turns or insulation breakdown within the solenoid coil using interrupted-current test methods. A technique slated for later investigation is monitoring coil hum or chatteringm, using acoustic sensors or electrical noise indications. Experimental results are presented demonstrating the technical feasibility and practicality of the diagnostic techniques being assessed in this continuing study.
Laser versus conventional ignition of flames

A critical review and comparison of the initiation of combustion processes by conventional electric spark or thermal means with laser sources is presented. A description of the fundamentals of ignition processes is used as the basis for interpretation of experimental and theoretical studies of laser ignition. It is shown that many features of laser ignition can be understood on the basis of simple thermal concepts, particularly when the effects of thermal or radical losses are considered. It is proposed that the main advantages of laser sources are likely to be in the timing and placement of ignition rather than the inherent energy requirements. Potential applications to combustion systems of practical importance, e.g., high-speed propulsion systems, are discussed and instructive laboratory-scale experiments are suggested.
Pore Pressure Estimation From Velocity Data: Accounting for Overpressure Mechanisms Besides Undercompaction

A new method for estimating pore pressure from formation sonic velocity data is presented. Unlike previous techniques, this method accounts for excess pressure generated by both undercompaction, and fluid expansion mechanisms such as aquathermal pressuring, hydrocarbon maturation, clay diagenesis, and charging from other zones. The method is an effective stress approach; the effective stress is computed from the velocity, and the result is subtracted from the overburden stress to obtain pore pressure. to include multiple sources of overpressure, a pair of velocity-vs.-effective-stress relations are introduced. One relation accounts for normal pressure and overpressure caused by undercompaction. The second is applied inside velocity reversal zones caused by fluid expansion mechanisms. Example applications of the method are presented from the U.S. gulf coast, the Gulf of Mexico, and the Central North Sea. some other pore pressure estimation approaches are also examined to demonstrate how these techniques have unknowingly accounted for overpressure mechanisms other than undercompaction. It is also explained how velocity-vs.-effective-stress data can be used to identify the general cause of overpressure in an area. For instance, the empirical correlation of Hottman and Johnson indicates that overpressure along the US gulf coast cannot be due only to undercompaction.
Regioselective Allylation of Ketones

Abstract In connection with our work concerning synthesis of insect pheromones,1 we became interested in reports by Lorette and Howard2 in which were described a method for preparing alpha-allyl ketones. These authors reported that diallyl ketals (4), available by exchange between a ketone (1), allyl alcohol and 2,2-dimethoxypropane, suffer acid-catalyzed elimination to yield intermediate allyl enol ethers (5/6) which undergo subsequent Claisen rearrangement to provide the alpha-allyl ketone products (2/3). The scheme on the following page summarizes the conversions involved.
Synthetic methodology for the preparation of N-hydroxysulfamides.

Abstract A convenient synthesis of a variety of substituted N -hydroxysulfamides from chlorosulfonyl isocyanate is reported. Alkyl groups can be introduced selectively on the N -Boc nitrogen of key intermediates 1a or 1b using the Mitsunobu reaction with alcohols. Subsequently the nitrogen carrying the silyloxy group can be alkylated under traditional conditions. Deprotection to the desired N -hydroxysulfamide can be achieved in high yields. Using this method, a number of structurally diverse N -hydroxysulfamides have been prepared. The usefulness of this methodology has further been demonstrated by the synthesis of more complex targets such as bis-hydroxysulfamide 5 , and cyclic hydroxysulfamides 7 and 8 .
Polyakov Loops, Z(N) Symmetry, and Sine-Law Scaling

We construct an effective action for Polyakov loops using the eigenvalues of the Polyakov loops as the fun- damental variables. We assume Z(N) symmetry in the confined phase, a finite difference in energy densities between the confined and deconfined phases as T → 0, and a smooth connection to perturbation theory for large T. The low-temperature phase consists of N − 1 independent fields fluctuating around an explicitly Z(N) symmetric background. In the low-temperature phase, the effective action yields non-zero string tensions for all representations with non-trivial N-ality. Mixing occurs naturally between representations of the same N-ality. Sine-law scaling emerges as a special case, associated with nearest-neighbor interactions between Polyakov loop eigenvalues.
Total Synthesis of Δ12‐Prostaglandin J3, a Highly Potent and Selective Antileukemic Agent

A catalytic asymmetric total synthesis of the potent and selective antileukemic Δ12-prostaglandin J3 (Δ12-PGJ3) is described. The convergent synthesis proceeded through intermediates 2 and 3, formed enantioselectively from readily available starting materials and coupled through an aldol reaction followed by dehydration to afford stereoselectively the cyclopentenone alkylidene structural motif of the molecule.
A directed relation graph method for mechanism reduction

Abstract A systematic approach for mechanism reduction was developed and demonstrated. The approach consists of the generation of skeletal mechanisms from detailed mechanism using directed relation graph with specified accuracy requirement, and the subsequent generation of reduced mechanisms from the skeletal mechanisms using computational singular perturbation based on the assumption of quasi-steady-state species. Both stages of generation are guided by the performance of PSR for high-temperature chemistry and auto-ignition delay for low- to moderately high-temperature chemistry. The demonstration was performed for a detailed ethylene oxidation mechanism consisting of 70 species and 463 elementary reactions, resulting in a specific skeletal mechanism consisting of 33 species and 205 elementary reactions, and a specific reduced mechanism consisting of 20 species and 16 global reactions. Calculations for laminar flame speeds and nonpremixed counterflow ignition using either the skeletal mechanism or the reduced mechanism show very close agreement with those obtained by using the detailed mechanism over wide parametric ranges of pressure, temperature, and equivalence ratio.
The Force Law of Classical Electrodynamics: Lorentz versus Einstein and Laub

We discuss the advantages of the force law proposed by Einstein and Laub in 1908 over the standard force law of Lorentz. The Einstein-Laub law is consistent with Maxwell’s equations, with the conservation laws, and with special relativity.
Factors influencing the intensity of magnetospheric substorms

A definition of the substorm is presented, and it is shown that the typical isolated substorm is produced by the superposition of effects of processes directly driven by the solar wind through dayside reconnection and those driven by unloading through nighttime reconnection. The single factor that determines whether a substorm will occur or not is the clock angle of the interplanetary magnetic field (IMF) around the earth-sun line. Only when this field points south of the GSM equatorial plane do the auroral electrojet indices depart from their quiet values. For a given clock angle, the level of activity increases with the IMF strength and solar wind velocity.
OCRS: an interactive object-based image clustering and retrieval system

In this paper, we propose an Interactive Object-based Image Clustering and Retrieval System (OCRS). The system incorporates two major modules: Preprocessing and Object-based Image Retrieval. In preprocessing, an unsupervised segmentation method called WavSeg is used to segment images into meaningful semantic regions (image objects). This is an area where a huge number of image regions are involved. Therefore, we propose a Genetic Algorithm based algorithm to cluster these images objects and thus reduce the search space for object-based image retrieval. In the learning and retrieval module, the Diverse Density algorithm is adopted to analyze the user's interest and generate the initial hypothesis which provides a prototype for future learning and retrieval. Relevance Feedback technique is incorporated to provide progressive guidance to the learning process. In interacting with user, we propose to use One-Class Support Vector Machine (SVM) to learn the user's interest and refine the returned result. Performance is evaluated on a large image database and the effectiveness of our retrieval algorithm is demonstrated through comparative studies.
Kinestatic Analysis of General Parallel Manipulators

Robotic mechanisms in general can be of either serial-chain, parallel-chain, or hybrid (a combination of both parallel and serial chains) geometry. While it can be asserted that kinematic theories and techniques are well established for fully serial-chain manipulators, the same assertion cannot be made when it is considered in the general context. In this article, we present a general procedure for systematic formulation and characterization of the instantaneous kinematics for a robotic mechanism with a general parallel-chain geometry. A kinestatic approach based on screw system theory is adopted in this treatment. The resulting equation is a compact Jacobian matrix of the system which includes attributes from not only the active joints but also the passive constraints. An example has been provided to demonstrate the methodology as well as its theoretical feasibility.
LUBM: A benchmark for OWL knowledge base systems

We describe our method for benchmarking Semantic Web knowledge base systems with respect to use in large OWL applications. We present the Lehigh University Benchmark (LUBM) as an example of how to design such benchmarks. The LUBM features an ontology for the university domain, synthetic OWL data scalable to an arbitrary size, 14 extensional queries representing a variety of properties, and several performance metrics. The LUBM can be used to evaluate systems with different reasoning capabilities and storage mechanisms. We demonstrate this with an evaluation of two memory-based systems and two systems with persistent storage.
Insights into the Electrochemical Reductive Cyclization of α,β-Unsaturated Carbonyl Derivatives

Abstract A series of acyclic and cyclic α,β-unsaturated esters bearing tethered mesylate leaving groups have been electrochemically reduced to give synthetically useful yields of monocyclic and bicyclic esters via attack of the β-carbon of the α,β-unsaturated ester on the carbon bearing the mesylated moiety.
On the Characterization of Expansion Maps for Self-Affine Tilings

We consider self-affine tilings in ℝn with expansion matrix φ and address the question which matrices φ can arise this way. In one dimension, λ is an expansion factor of a self-affine tiling if and only if |λ| is a Perron number, by a result of Lind. In two dimensions, when φ is a similarity, we can speak of a complex expansion factor, and there is an analogous necessary condition, due to Thurston: if a complex λ is an expansion factor of a self-similar tiling, then it is a complex Perron number. We establish a necessary condition for φ to be an expansion matrix for any n, assuming only that φ is diagonalizable over ℂ. We conjecture that this condition on φ is also sufficient for the existence of a self-affine tiling.
Padding Required: Assessing the Economic Impact of the Super Bowl

Civic boosters generally have estimated the Super Bowl to have an impact of $300 to $400 million on a host city’s economy. The National Football League has used the promise of an economic windfall to convince skeptical cities that investments in new stadiums for their teams in exchange for the right to host the event makes economic sense. Evidence from host cities from 1970-2001 indicates the Super Bowl contributes approximately one-quarter of what the boosters have promised and that the game could not have contributed by any reasonable standard of statistical significance, more than $300 million to host economies.
PROBLEMS OF INTERPRETATION IN THE CHEMICAL PATHOLOGY OF SCHIZOPHRENIA

Publisher Summary This chapter discusses problems related to interpretation in the chemical pathology of schizophrenia. Researchers believe that all of the changes noted in schizophrenic brains must be considered nonspecific or artifactual either on the basis of inadequate criteria for normative ranges of histological appearances, or as the result of age changes or other somatic influences of the many kinds prevalent in a chronic schizophrenic population, or to inadequate standardization of fixation and histological preparative procedures. The first and the most important problem is the nosology of mental disease, the assignments of subjects to class and subclass representing publicly verifiable and operationally or ostensivly definable ensembles. This is absolutely essential for establishment of meaningful correlations between psychopathology and biological phenomena. The second problem (already alluded to) is that of biological variability that, in the case of the nervous system, is a two-dimensional problem. Intraspecies ranges of normative data values, particularly for metabolic indices, are very great and especially so in an outbred species.
An NMR study of the mode of incorporation of ethene into propene in the Fischer-Tropsch reaction over cobalt

Incorporation of added ethene into the propene fraction formed by the Fischer-Tropsch reaction over cobalt supported on Al metal has been studied. Either the CO or the C{sub 2}H{sub 4} in the feed gas was labeled with {sup 13}C, and the products were studied by {sup 13}C NMR spectroscopy. All of the propene isotopomers which contain the {sup 13}C label could be identified. The formation of products which contain a single-labeled atom from the (doubly labeled) ethene feed was observed; this required that some of the ethene dissociate to C{sub 1} fragments. Among doubly labeled propenes, there was a strong preference for those isotopomers with the labels on adjacent carbon atoms. This could best be accounted for by a model which assumes that some ethene incorporation occurs as a C{sub 2} unit. The spectra gave no evidence that two C{sub 1} units, one from CO and one from ethene, recombine to give C{sub 2}H{sub 4} in the product mixture.
High-resolution heavy-ion-induced X-ray satellite emission study of implanted sulfur as a probe of co-implanted oxygen in an oxide substrate

Abstract Using high-resolution measurements, the relative fluorescence yields of the sulfur K α L n X-ray satellite lines produced by 24 MeV Si q + ion irradiation of a series of quartz glass targets co-implanted to equal doses and depths of sulfur and oxygen have been obtained and compared to the yields from targets implanted to the same depth with sulfur only. The data exhibit lower yields in the higher-order KL n satellite lines for the co-implanted oxygen targets but similar dose dependent curves. These results are consistent with oxygen increasing the valence electron density of the local sulfur environment. They also suggest that, with an appropriate choice of a probe ion, HIXSE may be capable of detecting impurity ions in matrices that normally mask the impurity, e.g., oxygen in oxide substrates.
Exactness and the Novikov conjecture

Abstract In this note we will study a connection between the conjecture that C ∗ r (Γ) is exact and the Novikov conjecture for Γ. The main result states that if the inclusion of the reduced C ∗ -algebra C r ∗ (Γ) of a discrete group Γ into the uniform Roe algebra of Γ, UC ∗ (Γ) , is a nuclear map then Γ is uniformly embeddable in a Hilbert space. By a result of Yu (Invent. Math. 139 (2000) 201) this implies that Γ satisfies the Novikov conjecture. Note that the hypothesis is a slight strengthening of the usual notion of exactness since a group Γ is exact if and only if the inclusion of C r ∗ (Γ) into B (l 2 (Γ)) is nuclear.
Large-scale equatorward transport of ozone in the subtropical lower stratosphere

[1] Anomalous vertical profiles of ozone were observed in the subtropical lower stratosphere (near south Florida) in July 2002 during the NASA-sponsored Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment measurement campaign. It is shown that there is an enhancement of ozone (initially >150%) above the tropopause extending up to ∼410 K potential temperature. This ozone increase is the result of recent transport of middle-and high-latitude lower stratospheric air into the subtropics. This meridional transport was a consequence of a geostrophic flow pattern established by a quasi-stationary anticyclone centered over the south central United States that persisted for much of July 2002. We show the spatial and temporal extent of meridional isentropic transport into the subtropics by examining the ozone vertical profiles in combination with the NOy:O3 correlations as well as isentropic back trajectory calculations. The anomalous ozone profiles are also reproduced in a global chemical transport model.
Rhodium-catalyzed regio- and enantioselective amination of racemic secondary allylic trichloroacetimidates with N-methyl anilines

We report the chiral diene ligated rhodium-catalyzed dynamic kinetic asymmetric transformation (DYKAT) of racemic secondary allylic trichloroacetimidates with a variety of N-methyl anilines, providing allylic N-methyl arylamines in high yields, regioselectivity, and enantiomeric excess. The rhodium-catalyzed DYKAT method addresses limitations previously associated with this particular class of aromatic nitrogen nucleophiles.
1,2-Bridged Quadricyclanes

The readily available benzodihydropentalene 6 and dimethyl acetylene-dicarboxylate react to give norbornadiene diester 8, with a three-carbon bridge from C1 to C2. Inrradiation of 8 gives the corresponding C1-C2 bridged quadricyclane diester 9, a new ring system. Diester 9 is quite stable, reverting to 8 with a t1/2 of 30 min at 170°C. The corresponding diacid 11, also prepared, reverts to its norbornadiene precursor at a considerably lower temperature, possibly as a consequence of acid catalysis.