cssi/SciSciGPT-SciSciNet huggingface dataset:
Differential Regulation of Neutrophil CD18 Integrin Function by Di- and Tri-Valent Cations: Manganese vs. Gadolinium

Affinity regulation of integrin function plays an important role during both leukocyte–endothelial and leukocyte–leukocyte interactions. We compared the roles of Mn2+ (Manganese) and Gd3+ (Gadolinium) in regulating leukocyte CD18-integrin function. We observed that: (i) Both cations prolonged neutrophil homotypic aggregation following chemoattractant IL-8 stimulation, with Gd3+ being effective at doses two orders of magnitude (10 μM range) lower that Mn2+. (ii) While both Gd3+ and Mn2+ mediate homotypic cell aggregation via l-selectin and CD18 integrins, their effects on the integrin subunits, LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18), was different. Gd3+ altered both LFA-1 and Mac-1 function, while the dominant effect of Mn2+ was on Mac-1. This effect of Gd3+ on LFA-1 function was confirmed in cell-free studies that measured the binding of recombinant ICAM-1 to LFA-1 immobilized on beads. (iii) Both ions augmented the binding of 327C, an antibody that recognizes active CD18 on human neutrophils, both in the presence and absence of exogenous IL-8. The effects of Mn2+ was more pronounced since it caused 3–4-fold increase in mAb 327C binding to neutrophils compared to Gd3+ which increased antibody binding by only ∼80%. 327C binding was partially reduced by Ca2+. Further, 327C binding induced by Mn2+ did not correlate tightly with cell adhesion function. (iv) In studies that monitored intracellular Ca2+ ([Ca2+]i), the addition of Mn2+ but not Gd3+ to neutrophils altered [Ca2+]i levels. Overall, while both Gd3+ and Mn2+ stabilize high affinity CD18 mediated cell adhesion, Gd3+ affects integrin conformation while Mn2+ may also trigger other effects.
Time orientation and asset prices

We analyze a general-equilibrium asset pricing model where a small subset of the consumers/investors have a short-run ‘‘urge to save’’. That is, their attitude toward consumption in the long run is a standard one F they do place zero weight on consumption far enough out in the future F but their short-run effective rates of discount may be negative. Our model, which is an elaboration on the framework proposed by Faruk Gul and Wolfgang Pesendorfer, does not feature time inconsistencies. Thus, we view consumers as fully rational, but subject to specific ‘‘internal frictions’’ in the form of temptation and self-control problems. The model nests the Mehra–Prescott model and we use it as a way of interpreting the wealth and asset pricing data. Some aspects of these data, we argue, can possibly be better understood using our model than the standard one. r 2002 Published by Elsevier Science B.V.
DOMESTIC STATE VIOLENCE: REPRESSION FROM THE CROQUANTS TO THE COMMUNE

Putting down a revolt always risks seeing the legitimate use of force degenerate into an excessive and discredited repression, here called domestic state violence. Sergio Cotta's analytical model of the difference between force and violence helps to reveal the significance of various cycles of revolt and repression over three centuries of French history. Oscillations between measured coercive force and domestic state violence divide these three centuries into six stages: early absolutist (1594–1639), Louisquatorzian (1640–75), themistocratic (1675–1789), revolutionary (1792–5), late republican (1797–1802), and liberal authoritarian (1802–71). Continuities existed across all of these stages, such as the recourse to regular troops and summary justice; however, periods of rapid socio-political realignment caused the use of force to become domestic state violence. In order to overcome the alienation this produced, the state created new means of restricting its use of force while still protecting the new social order. The years 1797–1802 constituted the pivotal phase of this process because this was when so many methods of repression developed during the era between early absolutism and the Terror were revived, only now wrapped in the restraints of legal-rational authority. The resulting ‘liberal authoritarianism’ persisted until the 1880s without substantial changes other than growth in the sheer magnitude of repression.
Low-rank matrix completion using alternating minimization

Alternating minimization represents a widely applicable and empirically successful approach for finding low-rank matrices that best fit the given data. For example, for the problem of low-rank matrix completion, this method is believed to be one of the most accurate and efficient, and formed a major component of the winning entry in the Netflix Challenge [17].In the alternating minimization approach, the low-rank target matrix is written in a bi-linear form, i.e. X = UV†; the algorithm then alternates between finding the best U and the best V. Typically, each alternating step in isolation is convex and tractable. However the overall problem becomes non-convex and is prone to local minima. In fact, there has been almost no theoretical understanding of when this approach yields a good result.In this paper we present one of the first theoretical analyses of the performance of alternating minimization for matrix completion, and the related problem of matrix sensing. For both these problems, celebrated recent results have shown that they become well-posed and tractable once certain (now standard) conditions are imposed on the problem. We show that alternating minimization also succeeds under similar conditions. Moreover, compared to existing results, our paper shows that alternating minimization guarantees faster (in particular, geometric) convergence to the true matrix, while allowing a significantly simpler analysis.
Innovation capability and post-IPO performance

This paper studies how firms’ innovation capability is related to their stock performance and eventual survival for a sample of biotech IPO firms. We create product-related measures of firms’ innovation capability by tracking the changes in R&D expenses, products, patents, strategic alliances, and product development stages for our sample firms, as disclosed in their IPO prospectuses and third post-IPO 10-K filings. We find that innovation capability is critical to contemporaneous stock performance and eventual firm survival. Biotech IPO firms are more likely to succeed in the long run, if they are able to expand the scale of their research undertakings and make progress in these research activities.
Electoral Competition When Some Candidates Lie and Others Pander

In this paper we analyze a two-candidate electoral competition in which a candidate can either lie about his private policy preference in order to get elected, or pander to post-election external influences in choosing a policy to implement. Both the pre-election announcement and post-election implementation are a candidate’s strategic choices. We show that, in equilibrium, different types of candidates can cluster at different points around the median voter position, as long as the pandering type and the lying type coexist in the candidate pool. The pooling of all types of candidates at the median voter position is also an equilibrium. Thus, despite pressure towards the median (as all candidates want to win the election), both convergence and divergence in candidate announcements are normal outcomes of electoral competition.
Mutational Analysis of the Chlamydia muridarum Plasticity Zone

Pathogenically diverse Chlamydia spp. can have surprisingly similar genomes. Chlamydia trachomatis isolates that cause trachoma, sexually transmitted genital tract infections (chlamydia), and invasive lymphogranuloma venereum (LGV) and the murine strain Chlamydia muridarum share 99% of their gene content. A region of high genomic diversity between Chlamydia spp. termed the plasticity zone (PZ) may encode niche-specific virulence determinants that dictate pathogenic diversity. We hypothesized that PZ genes might mediate the greater virulence and gamma interferon (IFN-γ) resistance of C. muridarum compared to C. trachomatis in the murine genital tract. To test this hypothesis, we isolated and characterized a series of C. muridarum PZ nonsense mutants. Strains with nonsense mutations in chlamydial cytotoxins, guaBA-add, and a phospholipase D homolog developed normally in cell culture. Two of the cytotoxin mutants were less cytotoxic than the wild type, suggesting that the cytotoxins may be functional. However, none of the PZ nonsense mutants exhibited increased IFN-γ sensitivity in cell culture or were profoundly attenuated in a murine genital tract infection model. Our results suggest that C. muridarum PZ genes are transcribed—and some may produce functional proteins—but are dispensable for infection of the murine genital tract.
Intramolecular syn and anti hydrosilylation and silicon-assisted cross-coupling: highly regio- and stereoselective synthesis of trisubstituted allylic alcohols.

The geometrical isomers of 6-ethylidenedioxadisilacyclohexane were prepared by intramolecular hydrosilylation of an unsymmetrical disiloxane by the use of Pt (syn) and Ru (anti) catalysts. This new class organosilicon reagents underwent cross-coupling reactions with a range of aryl iodides to afford (E)- and (Z)-trisubstituted allylic alcohols in a highly stereospecific fashion.
Loop shaping control of a model-story building using smart materials

This research concerns active vibration control of a two-story model structural frame by using the method of loop shaping. Piezoceramic smart materials, in particular the PZT (Lead Zirconate Titanate) in the form of patches, are surface-bonded on the structure and function as actuators and sensors. Sensitivity charts are introduced to assist the control system design. A nonparametric system identification is performed to obtain the frequency response function of the model building. A loop-shaped controller is designed using sensitivity charts. The effectiveness of the designed controller is demonstrated by shaker table tests where data from four earthquakes is used for excitation of the structure. The experimental results clearly show that the loop shaping based controller reduces the vibrations experienced by the structure during seismic activities.
Performance bounds on image registration

Registration is a fundamental step in image processing systems where there is a need to match two or more images. Applications include motion detection, target recognition, video processing, and medical imaging. Although a vast number of publications have appeared on image registration, performance analysis is usually performed visually, and little attention has been given to statistical performance bounds. Such bounds can be useful in evaluating image registration techniques, determining parameter regions where accurate registration is possible, and choosing features to be used for the registration. In this paper, Crame/spl acute/r-Rao bounds on a wide variety of geometric deformation models, including translation, rotation, shearing, rigid, more general affine and nonlinear transformations, are derived. For some of the cases, closed-form expressions are given for the maximum-likelihood (ML) estimates, as well as their variances, as space permits. The bounds are also extended to unknown original objects. Numerical examples illustrating the analytical performance bounds are presented.
Footstep navigation for dynamic crowds

The majority of previous crowd 'steering algorithms model each character as an oriented particle that moves by choosing a force or velocity vector. In many cases, orientation is heuristically chosen to be the same as the particle's velocity. This approach has the two key disadvantages: Limited locomotion constraints: Vector commands do not account for constraints of real human movement. Trajectories may have discontinuous velocities, oscillations, awkward orientations, or may try to move a character unnaturally, and these side-effects make it harder to animate the character intelligently. or example, a character moving forward cannot easily step to the right when its left foot is in the air (swing phase). Limited navigation control: It is common to assume that an animation system will automatically know how to interpret a vector-based steering decision. However a vector does not have enough information to indicate appropriate subtle maneuvers, such as side-stepping versus reorienting the torso, stepping backwards versus turning around, stopping and starting, planting a foot to change momentum quickly, or carefully placing footsteps in exact locations. These details are critical to depicting a character's local steering intelligence, and thus it is appropriate for steering to have better control.
Antiaromaticity in monocyclic conjugated carbon rings.

1326 10. Summary 1327 11. Triplet States 1327 12. Origin of Aromaticity and Antiaromaticity 1328 13. References 1330
Are Your Wages Set in Beijing

The economic troubles of less-skilled workers in the United States. and OECD-Europe during a period of rising manufacturing imports from third world countries has created a debate about whether, in a global economy, wages or employment are determined by the global rather than domestic labor-market conditions. One side argues that trade is all that matters; another side, that trade does not matter at all. The author rejects these polar views; empirical analysis has found modest but real trade effects in displacement of less-skilled labor and declines in the price of goods produced by low-skilled workers.
Sol–Gel Route to Synthesis of Microporous Ceramic Membranes: Preparation and Characterization of Microporous TiO2 and ZrO2 Xerogels

This paper focuses on the preparation and characterization of pure TiO2 and ZrO2 xerogels. The preparation method is based on a sol–gel technique using metal tert-amyloxides as precursors to produce nano-sized metal oxide particles which are subsequently packed in a gelation process, eventually resulting in microporous xerogele. The unsupported TiO2 and ZrO2 xerogele produced in this manner have a mean pore diameter less than 2 nm and more than 50% microporosity. However, these gels, in their pure form, are thermally stable only to 350°C. Improved thermal stabilities of mixed metal oxide xerogels will be reported elsewhere.
Existence and stability of periodic orbits of periodic difference equations with delays

In this paper, we investigate the existence and stability of periodic orbits of the p-periodic difference equation with delays xn = f (n − 1,xn−k). We show that the periodic orbits of this equation depend on the periodic orbits of p autonomous equations when p divides k. When p is not a divisor of k, the periodic orbits depend on the periodic orbits of gcd(p,k) nonautonomous p gcd(p,k) periodic difference equations. We give formulas for calculating the number of different periodic orbits under certain conditions. In addition, when p and k are relatively prime integers, we introduce what we call the pk-Sharkovsky’s ordering of the positive integers, and extend Sharkovsky’s theorem to periodic difference equations with delays. Finally, we characterize global stability and show that the period of a globally asymptotically stable orbit must divide p.
The effects of cosmic rays and solar flares on the IRAC detectors: the first two years of in-flight operation

The Infrared Array Camera (IRAC) is a four-channel camera on the Spitzer Space Telescope, one of three focal plane science instruments. IRAC uses two pairs of 256×256 pixel InSb and Si:As IBC detectors to provide simultaneous imaging at 3.6, 4.5, 5.8, and 8 μm. IRAC experiences a flux of cosmic rays and solar protons that produce transient effects in science images from each of the arrays, with 4 – 6 pixels per second being affected during each integration. During extreme solar flares, IRAC experiences a much higher rate of transients which affects the science data quality. We present cosmic ray rates and observed detector characteristics for IRAC during the first two years of science operation, and rates observed in a period of elevated solar proton flux during an intense solar flare in January 2005. We show the changes to the IRAC detectors observed since launch, and assess their impacts to the science data quality.
Geological fluvial geomorphology

The history of American fluvial geomorphology over the past century is viewed as one of conflict and crises. From 1888 to 1938, a controversy arose between (1) a rational approach to understanding landscape genesis and history, with its roots in geology, and (2) a spatial-analytical approach to landscape classification and description, with its roots in geography. By the 1960s, geomorphology, led by fluvial studies, had changed its emphasis from historical studies to process studies, and the geology/geography dispute became irrelevant. Since the 1960s, a new conflict has arisen between (1) problem-oriented studies of landform genesis and (2) method-oriented studies. The latter emphasize useful predictions and a methodology that generates respect from other scientific and engineering disciplines. In extreme cases, approach 2 may bypass the understanding of phenomena in order to generate useful predictions of systems assumed to embody the behavior of those phenomena. In order to achieve its goal of intellectually satisfying understanding of phenomena, approach 1 may require the stimulus of the occasional outrageous hypothesis, thereby posing a seeming anathema to an existing scientific program. The identification and explanation of anomalies is critical to approach 1. Because of the inherent conflict in these approaches to fluvial geomorphology, there is a need to balance opposing tendencies.
International migration, remittances, and poverty in developing countries

Few studies have examined the impact of international migration and remittances on poverty in a broad cross-section of developing countries. The authors try to fill this gap by constructing a new data set on poverty, international migration, and remittances for 74 low- and middle-income developing countries. Four key findings emerge: 1) International migration-defined as the share of a country's population living abroad-has a strong, statistical impact in reducing poverty. On average, a 10 percent increase in the share of international migrants in a country's population will lead to a 1.9 percent decline in the share of people living in poverty ($1.00 a person a day). 2) Distance to a major labor-receiving region-like the United States or OECD (Europe)-has an important effect on international migration. Developing countries that are located closest to the United States or OECD (Europe) are also those countries with the highest rates of migration. 3) An inverted U-shaped curve exists between the level of country per capita income and international migration. Developing countries with low or high per capita GDP produce smaller shares of international migrants than do middle-income developing countries. The authors find no evidence that developing countries with higher levels of poverty produce more migrants. Because of considerable travel costs associated with international migration, international migrants come from those income groups which are just above the poverty line in middle-income developing countries. 4) International remittances-defined as the share of remittances in country GDP-have a strong, statistical impact in reducing poverty. On average, a 10 percent increase in the share of international remittances in a country's GDP will lead to a 1.6 percent decline in the share of people living in poverty.
Isogenies of elliptic curves and the Morava stabilizer group

Let S2 be the p-primary second Morava stabilizer group, C a supersingular elliptic curve over Fp, O the ring of endomorphisms of C, and ‘ a topological generator of Z ◊ (respectively Z ◊ /{±1} if p = 2). We show that for p > 2 the group O [1/‘] ◊ of quasi-endomorphisms of degree a power of ‘ is dense in S2. For p = 2, we show that is dense in an index 2 subgroup of S2. AMS classification: Primary 11R52. Secondary 14H52, 55Q51.
The kurtosis of the cosmic shear field

We study the fourth-order moment of the cosmic shear field using the dark matter halo approach to describe the non-linear gravitational evolution of structure in the Universe. Since the third-order moment of the shear field vanishes because of symmetry, non-Gaussian signatures in its one-point statistics emerge at the fourth-order level. We argue that the shear kurtosis parameter S γ , 4 ≡ (γ 4 i ) c /(γ 2 i ) 3 may be more directly applicable to realistic data than the well-studied higher-order statistics of the convergence field, since obtaining the convergence requires a non-local reconstruction from the measured shear field. We compare our halo model predictions for the variance, skewness and kurtosis of lensing fields with ray-tracing simulations of cold dark matter models and find good agreement. The shear kurtosis calculation is made tractable by developing approximations for fast and accurate evaluations of the eight-dimensional integrals necessary to obtain the shear kurtosis. We show that on small angular scales, θ? 5 arcmin, more than half of the shear kurtosis arises from correlations within massive dark matter haloes with M? 10 1 4 M a . The shear kurtosis is sensitive to the matter density parameter of the Universe, li m o , and has relatively weak dependences on other parameters. Therefore, a detection of the shear kurtosis can be used to break degeneracies in determining li m o and the power spectrum amplitude a 8 so far provided from measurements of the two-point shear statistics. The approximations we develop for the third-and fourth-order moments allow for accurate halo model predictions for the three-dimensional mass distribution as well. We demonstrate their accuracy in the small-scale regime, below 2 Mpc, where analytical approaches used in the literature so far cease to be accurate.
High resolution spectroscopy with a femtosecond laser frequency comb

The output of a mode-locked femtosecond-laser is used for high resolution spectroscopy of Cs in an atomic beam. The laser is referenced directly to a stable RF signal from the NIST time-scale. By changing the laser's repetition rate, the Cs D/sub 1/ and D/sub 2/ transitions are detected with high resolution.
The Proton Form Factor Ratio Measurements at Jefferson Lab

The ratio of the proton form factors, G{sub Ep}/G{sub Mp}, has been measured from Q{sup 2} of 0.5 GeV{sup 2} to 8.5 GeV{sup 2}, at the Jefferson Laboratory, using the polarization transfer method. This ratio is extracted directly from the measured ratio of the transverse and longitudinal polarization components of the recoiling proton in elastic electron-proton scattering. The discovery that the proton form factor ratio measured in these experiments decreases approximately linearly with four-momentum transfer, Q{sup 2}, for values above ~1 GeV{sup 2}, is one of the most significant results to come out of JLab. These results have had a large impact on progress in hadronic physics; and have required a significant rethinking of nucleon structure. The increasingly common use of the double-polarization technique to measure the nucleon form factors, in the last 15 years, has resulted in a dramatic improvement of the quality of all four nucleon electromagnetic form factors, G{sub Ep}, G{sub Mp}, G{sub En} and G{sub Mn}. There is an approved experiment at JLab, GEP(V), to continue the ratio measurements to 12 GeV{sup 2}. A dedicated experimental setup, the Super Bigbite Spectrometer (SBS), will be built for this purpose. It will be equipped with a focal planemore » polarimeter to measure the polarization of the recoil protons. The scattered electrons will be detected in an electromagnetic calorimeter. In this presentation, I will review the status of the proton elastic electromagnetic form factors and discuss a number of theoretical approaches to describe nucleon form factors.« less
Nickel-Catalyzed Stereoselective Formation of α-2-Deoxy-2-Amino Glycosides

The development of a new method for the stereoselective synthesis of α-2-deoxy-2-amino glycosides is described. This methodology relies on the nature of the cationic nickel catalyst, generated in situ from LnNiCl2 and AgOTf, to direct the anomeric stereoselectivity. The new glycosylation reaction is highly α-selective and proceeds under mild conditions with 5−10 mol % of the nickel catalyst loading at ambient temperature. This new method has been applied to both d-glucosamine and galactosamine trichloroacetimidate donors as well as an array of primary, secondary, and tertiary alcohol nucleophiles to provide the desired glycoconjugates in good yields with excellent α-selectivity. Mechanistic studies of the present reaction are underway and will be reported in due course.
InCl3-Catalyzed Domino Reaction of Aromatic Amines with Cyclic Enol Ethers in Water: A Highly Efficient Synthesis of New 1,2,3,4-Tetrahydroquinoline Derivatives

The tetrahydroquinoline moiety is a structural feature of many natural products. By using a domino reaction of aromatic amines and cyclic enol ethers or 2-hydroxy cyclic ether catalyzed by indium chloride in water, various tetrahydroquinoline derivatives were synthesized efficiently. Most cyclization products showed cis selectivity. The use of 2,3-dihydrofuran as the cyclic enol ether provided both higher reactivity and cis selectivity than the use of 3,4-dihydro-2H-pyran. The cis selectivity was tentatively rationalized due to chelation control in water.
Does the “Community Prosecution” Strategy Reduce Crime? A Test of Chicago's Experience

A new strategy of criminal prosecution, called “community prosecution,” emerged in the past two decades. The strategy breaks with the traditional approach to prosecution in which a prosecutor works in an office adjacent to a criminal court, processes a large volume of cases, and measures success with conviction rates and sentence lengths. In community prosecution, a prosecutor works directly in a neighborhood, develops relationships with local groups, aligns enforcement priorities with residents’ public safety concerns, and seeks solutions to prevent crime. This article presents the first estimates of community prosecution’s impact on crime. Over a fifteen-year period, Chicago’s top prosecutor twice applied the community prosecution strategy in some (but not all) neighborhoods, and this sequence of two “off/on” policy episodes permits plausible identification of the strategy’s impact. Differences-in-differences estimates show that community prosecution reduced certain categories of crime, such as aggravated assault, but had no effect on other categories, such as larceny. The diversity of practicesundertherubricofcommunityprosecutionmakesgeneralizationdifficult,butthe
Investing in a Global World

We examine active retail mutual funds and institutional products with a mandate to invest in global equity markets. We find little reliable evidence of alphas in the aggregate or on average. The right tail of the distribution contains some large alphas. Decomposing stock selection from country selection, we find some evidence of superior stock picking abilities in the extreme right tail. However, simulations suggest that they are produced just as likely by luck as by skill. Persistence tests show little evidence of continuation in superior performance.
Harmonic analysis associated with spatio-temporal transformations

The paper presents new developments in harmonic analysis associated with the motion transformations embedded in digital signals. In this context, harmonic analysis provides motion analysis with a complete theoretical construction of perfectly matching concepts and a related toolbox leading to fast algorithms. This theory can be built from only two assumptions: an associative structure for the local motion transformations expressed as a Lie group and a principle of optimality for the global evolution expressed as a variational extremal. Motion analysis means not only detection, estimation, interpolation, and tracking but also propagator's motion-compensated filtering, signal decomposition, and selective reconstruction. The optimality principle defines the trajectory and provides the appropriate equations of motion, the selective tracking equations, the selective constants of motion to be tracked, and all the symmetries to be imposed on the system. The harmonic analysis provides new special functions, orthogonal bases, partial differential equations (PDE), ordinary differential equations (ODE) and integral transforms. The tools to be developed rely on group representations, continuous and discrete wavelets, the estimation theory (prediction, smoothing and interpolation) and filtering theory (Kalman filters, motion-based convolutions, integral transforms). All the algorithms are supported by fast and parallelizable implementations based on the fast Fourier transform (FFT) and dynamic programming.
Pregnancy and Birth Control Counseling

Clinical illustrations of pregnancy counseling are given with clearly demarcated areas that a counselor should or should not get into. The author outlines the vital points that need to be covered in counseling: (a) failure to use contraception, (b) failure of contraceptive methods, (c) sexual attitudes, (d) concrete plans, and (e) referrals. Some of the topics discussed are: the use of emergency methods, sterilization, the meanings of incest, homosexuality, masturbation, and prostitution. The selection and training of counselors and the screening procedures are pointed up, with “how to” procedures outlined.
Prospects of a Search for Neutral, Long-Lived Particles using Photon Timing at CDF

We present the prospects of searches for neutral, long-lived particles which decay to photons using their time of arrival measured with a newly installed EMTiming system at CDF. Using GMSB models we estimate the expected 95% confidence level exclusion regions as a function of the neutralino mass and lifetime. We find that a combination of single photon and diphoton analyses should allow the Tevatron in run II to easily extend the exclusion regions from ALEPH at LEP II, and cover parts of the theoretically favored GMSB parameter space.
Tracking vehicles in congested traffic

For the problem of tracking vehicles on freeways using machine vision, existing systems work well in free-flowing traffic. Traffic engineers, however, are more interested in monitoring freeways when there is congestion, and current systems break down for congested traffic due to the problem of partial occlusion. We are developing a feature-based tracking approach for the task of tracking vehicles under congestion. Instead of tracking entire vehicles, vehicle sub-features are tracked to make the system robust to partial occlusion. In order to group together sub-features that come from the same vehicle, the constraint of common motion is used. In this paper we describe the system and experiments of our tracker/grouper on several minutes of videotape.
Perturbation analysis via coupling

Perturbation analysis is an efficient method for performance analysis of discrete event dynamic systems. It yields gradient information from only one sample path observation. Over the last two decades, various perturbation analysis techniques have been developed to handle a large class of problems. Coupling is a method of generating multiple random samples. It has wide range of applications in applied probability. The paper is concerned with perturbation analysis via coupling. This approach offers a great versatility of the form of gradient estimators, which is potentially useful for variance reduction and for efficient implementation. Several known perturbation analysis techniques can be reviewed as special ways of coupling. The coupling method is further applied to gradient estimation of Markov chains. The method is used not only in deriving a gradient estimator but also in its implementation. It is proved that the estimator is strongly consistent. Finally, different coupling schemes are compared using an illustrative example.
Characterization of a MEMS BioChip for planar patch-clamp recording

Abstract We describe a planar MEMS silicon structure to record ion channel currents in biological cells. The conventional method of performing an electrophysiological experiment, `patch-clamping', employs a glass micropipette. The micropipette tip is a source of thermal noise because of its inherent, tapered, conical structure, giving rise to a large pipette resistance. This pipette resistance, when coupled with the biological cell capacitance, limits the available bandwidth of single ion channel recording. In this work, we propose a current transport model to characterize the series resistance and capacitance of a planar pipette fabricated on a silicon BioChip. Our model provides a deeper insight into how currents injected into a micropore are quantitatively partitioned into the individual ion transports, and goes beyond just describing the solute and solvent kinetics inside pores of microscale dimensions. The device topology and fabrication sequence of the planar patch-clamp setup are also discussed. The theoretical predictions by the model are in close agreement with the experimental results.
Fan Noise Reduction From a Supersonic Inlet During Simulated Aircraft Approach

A series of experiments was conducted to investigate the radiation of fan noise from a supersonic inlet during a simulated aircraft approach. A scaled-down model of an axisymmetric, mixed-compression, supersonic inlet (P-inlet) was used in conjunction with a 10.4 cm (4.1 in) diameter turbofan engine simulator as the noise source. The tests were conducted at an outdoor facility under static conditions. The main goal of the experiment was to reduce the forward radiating fan noise by modifying the auxiliary inlet doors. The modified doors are designed to reduce the inlet distortion to the fan face. In addition, the new door design also uses a converging flow passage in order to take advantage of the noise attenuation due to the choking effect at the auwiliary door. The simulator was tested at 60 percent design speed in an attempt to match the simulator noise source to that of a real aircraft engine on approach. Both aerodynamic and acoustic measurements were taken in the experiments. The results show that when compared to the original design, the modified auxiliary inlet doors reduced the circumferential inlet distortion to the fan face by a factor of two. The key result is that the blade passing frequency tone has been decreased by an average of 6 dB in the forward sector for the modified door design. Results from the closed auxiliary inlet door case are also presented to provide additional comparisons
A membrane-free lithium/polysulfide semi-liquid battery for large-scale energy storage

Large-scale energy storage represents a key challenge for renewable energy and new systems with low cost, high energy density and long cycle life are desired. In this article, we develop a new lithium/polysulfide (Li/PS) semi-liquid battery for large-scale energy storage, with lithium polysulfide (Li2S8) in ether solvent as a catholyte and metallic lithium as an anode. Unlike previous work on Li/S batteries with discharge products such as solid state Li2S2 and Li2S, the catholyte is designed to cycle only in the range between sulfur and Li2S4. Consequently all detrimental effects due to the formation and volume expansion of solid Li2S2/Li2S are avoided. This novel strategy results in excellent cycle life and compatibility with flow battery design. The proof-of-concept Li/PS battery could reach a high energy density of 170 W h kg−1 and 190 W h L−1 for large scale storage at the solubility limit, while keeping the advantages of hybrid flow batteries. We demonstrated that, with a 5 M Li2S8 catholyte, energy densities of 97 W h kg−1 and 108 W h L−1 can be achieved. As the lithium surface is well passivated by LiNO3 additive in ether solvent, internal shuttle effect is largely eliminated and thus excellent performance over 2000 cycles is achieved with a constant capacity of 200 mA h g−1. This new system can operate without the expensive ion-selective membrane, and it is attractive for large-scale energy storage.
Testing the Limits of WestlawNext

Law students in Advanced Legal Research courses at two law schools completed a series of exercises designed to explore several discrete aspects of WestlawNext. Professor Peoples reports the results of this study concerning the impact of WestlawNext's pricing model, user interface, and search algorithm on research results. The article concludes with suggestions for improvement to WestlawNext and a call for librarians to become more involved in training students to use WestlawNext.
Finding approximate POMDP solutions through belief compression

Standard value function approaches to finding policies for Partially Observable Markov Decision Processes (POMDPs) are generally considered to be intractable for large models. The intractability of these algorithms is to a large extent a consequence of computing an exact, optimal policy over the entire belief space. However, in real-world POMDP problems, computing the optimal policy for the full belief space is often unnecessary for good control even for problems with complicated policy classes. The beliefs experienced by the controller often lie near a structured, low-dimensional subspace embedded in the high-dimensional belief space. Finding a good approximation to the optimal value function for only this subspace can be much easier than computing the full value function. We introduce a new method for solving large-scale POMDPs by reducing the dimensionality of the belief space. We use Exponential family Principal Components Analysis (Collins, Dasgupta, & Schapire, 2002) to represent sparse, high-dimensional belief spaces using small sets of learned features of the belief state. We then plan only in terms of the low-dimensional belief features. By planning in this low-dimensional space, we can find policies for POMDP models that are orders of magnitude larger than models that can be handled by conventional techniques. We demonstrate the use of this algorithm on a synthetic problem and on mobile robot navigation tasks.
Plus/minus grading and motivation: an empirical study of student choice and performance

This paper considers whether student motivation might be impacted by the replacement of a straight (A, B, C, D, F) grading system with a plus/minus system (A, A−, B+ … D−, F). The data that are examined are from several undergraduate economics classes at a mid‐sized midwestern university in the United States. The data includes student characteristics, student performance and students’ choices of either a plus/minus or a straight grading system. In this admittedly small‐scale study students, who chose plus/minus grading, were not significantly more motivated than students who opted for straight grading.
Pyran Annulation: Asymmetric Synthesis of 2,6-Disubstituted-4-methylene Tetrahydropyrans

A reaction process for the asymmetric construction of a variety of cis or trans disubstituted pyrans is described. This sequences allows for the asymmetric convergent union of two aldehydes with silyl-stannane reagent 1 in a two-step process: catalytic asymmetric allylation of the first aldehyde using 1 with a BITIP catalyst, followed by reaction of the alcohol so obtained with a second aldehyde and TMSOTf.
Schooling of girls and boys in a West African country: the effects of parental education, income, and household structure.

Abstract In this paper we investigate gender differences in the determinants of several schooling indicators—grade attainment, current enrollment, and withdrawal from school—in a poor urban environment in West Africa, using ordered and binary probit models incorporating household-level random effects. Increases in household income lead to greater investments in girls' schooling but have no significant impact on schooling of boys. Improvements in father's education raises the schooling of both sons and daughters (favoring the latter) but mother's education has significant impact only on daughters' schooling; these estimates are suggestive of differences in maternal and paternal preferences for schooling daughters relative to sons. Domestic responsibilities, represented for example by the number of very young siblings, impinge strongly on girls' education but not on boys'. Policies such as subsidized childcare that reduce the opportunity cost of girls' time in the home may therefore increase their ability to get an education. JEL 015, I21
Fast Algorithms for Aligning Sequences with Restricted Affine Gap Penalties

Affine gap penalties are generally considered appropriate for aligning DNA and protein sequences. (“Affine” means that a gap of length k is penalized α + kβ, i.e., it costs α to open up a gap plus β for each symbol in the gap.) For certain applications, such as aligning a cDNA sequence with a genomic DNA sequence, it might be adequate to use the restricted affine gap penalties which penalize long gaps with a constant penalty. As it turns out, several techniques developed for solving the approximate string matching problem can be utilized to yield efficient algorithms for computing the optimal alignment with restricted affine gap penalties. In particular, efficient algorithms can be derived based on the suffix automaton with failure transitions and on the diagonalwise monotonicity of the cost tables. To speedup the computation, the q-gram paradigm can be used to locate the interval in the longer sequence that should be aligned with the shorter sequence. We have implemented the above methods in C on Sun workstations running SunOS Unix. Preliminary experiments show that these approaches are very promising for aligning a cDNA sequence with a genomic DNA sequence.
Severe Mood Dysregulation, Irritability, and the Diagnostic Boundaries of Bipolar Disorder in Youths

In recent years, increasing numbers of children have been diagnosed with bipolar disorder. In some cases, children with unstable mood clearly meet current diagnostic criteria for bipolar disorder, and in others, the diagnosis is unclear. Severe mood dysregulation is a syndrome defined to capture the symptomatology of children whose diagnostic status with respect to bipolar disorder is uncertain, that is, those who have severe, nonepisodic irritability and the hyperarousal symptoms characteristic of mania but who lack the well-demarcated periods of elevated or irritable mood characteristic of bipolar disorder. Levels of impairment are comparable between youths with bipolar disorder and those with severe mood dysregulation. An emerging literature compares children with severe mood dysregulation and those with bipolar disorder in longitudinal course, family history, and pathophysiology. Longitudinal data in both clinical and community samples indicate that nonepisodic irritability in youths is common and is ...
HIGH-VELOCITY CLOUDS IN THE NEARBY SPIRAL GALAXY M 83

We present deep H I 21 cm and optical observations of the face-on spiral galaxy M 83 obtained as part of a project to search for high-velocity clouds (HVCs) in nearby galaxies. Anomalous-velocity neutral gas is detected toward M 83, with 5.6 ? 107 M ? of H I contained in a disk rotating 40-50 km s?1 more slowly in projection than the bulk of the gas. We interpret this as a vertically extended thick disk of neutral material, containing 5.5% of the total H I within the central 8 kpc. Using an automated source detection algorithm to search for small-scale H I emission features, we find eight distinct, anomalous-velocity H I clouds with masses ranging from 7 ? 105 to 1.5 ? 107 M ? and velocities differing by up to 200 km s?1 compared to the H I disk. Large on-disk structures are coincident with the optical spiral arms, while unresolved off-disk clouds contain no diffuse optical emission down to a limit of 27 r' mag per square arcsec. The diversity of the thick H I disk and larger clouds suggests the influence of multiple formation mechanisms, with a galactic fountain responsible for the slowly rotating disk and on-disk discrete clouds, and tidal effects responsible for off-disk cloud production. The mass and kinetic energy of the H I clouds are consistent with the mass exchange rate predicted by the galactic fountain model. If the HVC population in M 83 is similar to that in our own Galaxy, then the Galactic HVCs must be distributed within a radius of less than 25 kpc.
Optical and X-ray observations of the neutron star soft X-ray transient XTE J1709–267

In this paper we report on the discovery of the optical counterpart to the neutron star soft X-ray transient (SXT) XTE J1709-267 at an R-band magnitude of R = 20.5 ± 0.1 and 22.24 ± 0.03, in outburst and quiescence, respectively. We further report the detection of type I X-ray bursts in RXTE data obtained during an outburst of the source in 2002. These bursts show a precursor before the onset of the main burst event, reminiscent of photospheric radius expansion bursts. Sifting through the archival RXTE data for the burster 4U 1636-53, we found a nearly identical burst with precursor in 4U 1636-53. A comparison of this burst to true photospheric radius expansion bursts in 4U 1636-53 leads us to conclude that these bursts-with-precursor do not reach the Eddington limit. Nevertheless, from the burst properties we can derive that the distance to XTE J1709-267 is consistent with the distance of the Globular Cluster NGC 6293. We further report on the analysis of a 22.7 ks observation of XTE J1709-267 obtained with the Chandra satellite when the source was in quiescence. We found that the source has a soft quiescent spectrum which can be fit well by an absorbed black body or neutron star atmosphere model. A power law contributes less than ∼20 per cent to the 0.5-10 keV unabsorbed flux of (1.0 ± 0.3) × 10 -13 erg cm -2 s -1 . This flux is only slightly lower than the flux measured right after the outburst in 2002. This is in contrast to the recent findings for MXB 1659-29, where the quiescent source flux decreased gradually by a factor of ∼7-9 over a period of 18 months. Finally, we compared the fractional power-law contribution to the unabsorbed 0.5-10 keV luminosity for neutron star SXTs in quiescence for which the distance is well-known. We find that the power-law contribution is low only when the source quiescent luminosity is close to ∼1-2 x 10 33 erg s -1 . Both at higher and lower values the power-law contribution to the 0.5-10 keV luminosity increases. We discuss how models for the quiescent X-ray emission can explain these trends.