cssi/SciSciGPT-SciSciNet huggingface dataset:
A Facile Route to Vinyl- and Arylphosphonates by Vinyl and Aryl Radical Trapping with (MeO)3P

The generation of vinyl or aryl radicals under classical, thermal AIBN/n-Bu3SnH conditions at 80 °C in the presence of an excess of (MeO)3P gives rise to the corresponding vinyl- or arylphosphonates in good yields. This approach complements the photochemical reactions of the same systems previously used. Reactions with the individual stereoisomers of MeCHCHMeBr (thermal AIBN/n-Bu3SnH conditions) afford a radical-equilibrated 96/4 E/Z ratio of vinylphosphonates. Substitution of (TMS)3SiH for n-Bu3SnH yields an approximately 1/1 ratio of separable E and Z vinylphosphonate diastereomers.
Galaxy aggregates in the Coma cluster

ABSTRA C T We present evidence for a new morphologically defined form of small-scale substructure in the Coma cluster, which we call galaxy aggregates. Aggregates are dominated by a central galaxy, which is on average 5 mag brighter than the smaller aggregate members, nearly all of which lie to one side of the central galaxy. We have found three such galaxy aggregates: two dominated by the S0 galaxies RB 55 and RB 60, and one by the starbursting SBb NGC 4858. RB 55 and 60 are both equidistant between the two dominant D galaxies NGC 4874 and 4889, while NGC 4858 is located near the large E0 galaxy NGC 4860. All three central galaxies have redshifts consistent with Coma cluster membership. We describe the spatial structures of these unique objects, and suggest several possible mechanisms to explain their origin. These include: chance superpositions from background galaxies, interactions between other galaxies and with the cluster gravitational potential, and ram pressure. We conclude that the most probable scenario of creation is an interaction with the cluster through its gravitational potential.
A practical cross-layer mechanism for fairness in 802.11 networks

Many companies, organizations and communities are providing wireless hotspots that provide networking access using 802.11b wireless networks. Since wireless networks are more sensitive to variations in bandwidth and environmental interference than wired networks, most networks support a number of transmission rates that have different error and bandwidth properties. Access points can communicate with multiple clients running at different rates, but this leads to unfair bandwidth allocation. If an access point communicates with a mix of clients using both 1 Mb/s and 11 Mb/s transmission rates, the faster clients are effectively throttled to 1 Mb/s as well. This happens because the 802.11 MAC protocol approximate "station fairness", with each station given an equal chance to access the media. We provide a solution to provide "rate proportional fairness", where the 11 Mb/s stations receive more bandwidth than the 1 Mb/s stations. Unlike previous solutions to this problem, our mechanism is easy to implement, works with common operating systems and requires no change to the MAC protocol or the stations.
INDIGENT CARE AS QUID PRO QUO IN HOSPITAL REGULATION

Hospitals expend considerable resources each year to provide health care to the poor. Why do some hospitals voluntarily take on a disproportionate burden of this care? Our view is that the burdened hospitals are not simply altruistic. They are indirectly compensated for this expense with legal protections against competition under certificate-of-need (CON) regulation. We test this hypothesis in a recursive model, explaining which hospitals are likely to win CON approval. The results indicate that, controlling for the endogeneity of indigent care, regulators in Florida systematically awarded licenses to hospitals providing greater amounts of care to the poor.
Visualization Studies of a Shear Driven Three-Dimensional Recirculating Flow

A facility has been constructed to study shear-driven, recirculating flows. In this particular study, the circulation cell structure in the lid-driven cavity was studied as a function of the speed of the lid which provides the shearing force to a constant and uniform density fluid. The flow is three-dimensional and exhibits regions where Taylor-type instabilities and Taylor Goertler-like vortices are present. One main circulation cell and three secondary cells are present for the Reynolds number (based on cavity width and lid speed) range considered, viz., 1000-10000. The flows becomes turbulent at Reynolds numbers between 6000 to 8000. The transverse fluid motions (in the direction perpendicular to the lid motion) are significant. In spite of this, some key results from two-dimensional numerical simulations agree well with the results of the present cavity experiments.
Vibrational optical activity of oligopeptides

Vibrational optical activity (VOA) is a relatively newspectroscopic technique, which has two principal manifestations, ir vibrational CD and vibrational Raman optical activity. Progress in the study of oligopeptides using both of these forms of VOA is reviewed from the perspective of theoretical and instrumental techniques, spectral results, and structural interpretations. © 1994 John Wiley & Sons, Inc.
Alternate Pacing of Border-Collision Period-Doubling Bifurcations.

Unlike classical bifurcations, border-collision bifurcations occur when, for example, a fixed point of a continuous, piecewise C1 map crosses a boundary in state space. Although classical bifurcations have been much studied, border-collision bifurcations are not well understood. This paper considers a particular class of border-collision bifurcations, i.e., border-collision period-doubling bifurcations. We apply a subharmonic perturbation to the bifurcation parameter, which is also known as alternate pacing, and we investigate the response under such pacing near the original bifurcation point. The resulting behavior is characterized quantitatively by a gain, which is the ratio of the response amplitude to the applied perturbation amplitude. The gain in a border-collision period-doubling bifurcation has a qualitatively different dependence on parameters from that of a classical period-doubling bifurcation. Perhaps surprisingly, the differences are more readily apparent if the gain is plotted versus the perturbation amplitude (with the bifurcation parameter fixed) than if plotted versus the bifurcation parameter (with the perturbation amplitude fixed). When this observation is exploited, the gain under alternate pacing provides a useful experimental tool to identify a border-collision period-doubling bifurcation.
New perspectives for information systems education

Systems analysis is the examination of a problem situation in order to define the requirements of a solution, often computerized, to that problem. The diversity of problems and the constraints of computing technology require that a problem be thoroughly analyzed in order to insure that the problem is clearly understood. Then, and only then it can be determined how computing technology can be applied to solve the identified problem. Therefore, systems analysis education teaches the discipline of clear and complete problem definition.Several recent developments offer new perspectives for systems analysis education. These developments provide a conceptual framework for understanding information system and data base characteristics. This framework supports an improved methodology for systems analysis and thereby contributes to higher quality systems analysis education.
THE MASSIVE STAR POPULATION IN M101. I. THE IDENTIFICATION AND SPATIAL DISTRIBUTION OF THE VISUALLY LUMINOUS STARS

An increasing number of non-terminal giant eruptions are being observed by modern supernova and transient surveys. But very little is known about the origin of these giant eruptions and their progenitors, many of which are presumably very massive, evolved stars. Motivated by the small number of progenitors positively associated with these giant eruptions, we have begun a survey of the evolved massive star populations in nearby galaxies. The nearby, nearly face-on, giant spiral M101 is an excellent laboratory for studying a large population of very massive stars. In this paper, we present BVI photometry obtained from archival HST/ACS Wide Field Camera images of M101. We have produced a catalog of luminous stars with photometric errors <10% for V < 24.5 and 50% completeness down to V ∼ 26.5 even in regions of high stellar crowding. Using color and luminosity criteria, we have identified candidate luminous OB-type stars and blue supergiants, yellow supergiants, and red supergiants for future observation. We examine their spatial distributions across the face of M101 and find that the ratio of blue to red supergiants decreases by two orders of magnitude over the radial extent of M101 corresponding to 0.5 dex in metallicity. We discuss the resolvedmore » stellar content in the giant star-forming complexes NGC 5458, 5453, 5461, 5451, 5462, and 5449 and discuss their color-magnitude diagrams in conjunction with the spatial distribution of the stars to determine their spatio-temporal formation histories.« less
Effects of Lubricant Rheology and Kinematic Conditions on Micro-Elastohydrodynamic Lubrication

Influence de la rheologie du lubrifiant et des conditions cinematiques sur la lubrification microelastohydrodynamique
Do flexural stresses explain the mantle fault zone beneath Kilauea volcano

SUMMARY Recent relocation and focal mechanism analyses of deep earthquakes beneath Kilauea volcano, Hawaii indicate that seismicity is concentrated on a horizontal fault zone at a depth of 30 km, with seaward slip of the upper block on a low-angle plane. We discuss whether the observed localization of the earthquakes can be explained primarily by stresses induced by flexure of the Pacific Plate beneath the Hawaiian load. We find that flexural stresses are consistent with the observed fault plane orientation, and the direction and rate of slip. The mechanisms of mantle earthquakes in other regions of Hawaii are also consistent with the flexural calculation. However, the model has four shortcomings: (1) the fault zone is displaced 15–20 km to the NW of the region of predicted maximum shear stress; (2) the maximum shear stress on preferred fault planes in the vicinity of the fault zone seems too low to overcome Coulomb friction (by about a factor of 2, assuming hydrostatic pore pressure); (3) the fault zone is much more localized laterally than is the region of large flexural stresses and stressing rates and (4) the fault zone is more localized vertically than might be inferred from the calculation as well. Simple and plausible extensions of the plate flexure model that account for spatial variations in the location of pore fluids, and/or the possible existence of a passive low shear stress magma transport system can overcome most of these shortcomings. Several magma pipes would be necessary to explain the observed earthquake locations, and simple thermal arguments indicate that such pipes could be conduits for porous flow if they are a few kilometres in radius.
Explaining Changes in Organizational Form The Case of Professional Baseball

In this article, we investigate changes over time in the organization of the relationship between Major League Baseball and minor league baseball teams. We develop a model in which a minor league t...
Coarse differentiation and quasi-isometries of a class of solvable Lie groups II

In this paper, we continue with the results in [12] and compute the group of quasiisometries for a subclass of split solvable unimodular Lie groups. Consequently, we show that any finitely generated group quasi-isometric to a member of the subclass has to be polycyclic and is virtually a lattice in an abelian-by-abelian solvable Lie group. We also give an example of a unimodular solvable Lie group that is not quasi-isometric to any finitely generated group, as well deduce some quasi-isometric rigidity results. 51F99; 22E40
A New and Accurate Modeling Technique for Glass Resistance in Multiphase Multielectrode Glass Furnaces

One of the design elements involved in sizing the electrical power equipment for glass furnaces is the determination of the glass resistances between the operating electrodes. All methods used for this purpose to date are approximate and are based on a simple model considering the resistance between only two electrodes at the time. This paper presents a technique to develop a resistance model for any general configuration of electrodes and supply voltages in glass furnaces. The technique is based on relating the glass conductivity as represented by Ohm's law to the electrostatic property as represented by Gauss's law. The resistance model is then derived in a matrix form using the bus admittance frame of reference. A digital computer program has been developed to implement the proposed technique and example results are presented.
A Distorted Nation: Perceptions of Racial/Ethnic Group Sizes and Attitudes Toward Immigrants and Other Minorities

Using a special module (MEUS) of the 2000 General Social Survey, we investigate Americans' perceptions of the racial and ethnic composition of the United States. We show that, because of innumeracy, it is critical to gauge perceptions through relative, rather than absolute, group sizes. Even so, it appears that, as of 2000, roughly half of Americans believed that whites had become a numerical minority; such perceptions were even more common among minority-group members than among whites. Majority-group respondents'perceptions of the relative sizes of minorities affect their attitudes towards immigrants, blacks and Hispanics, with those having the most distorted perceptions holding the most negative attitudes. Although perceptions of group sizes in the nation are linked to the perceived racial/ethnic composition of the communities where respondents reside, the effects ofthe former on attitudes are largely independent of the latter. Our findings highlight the frequently overlooked value of an old bromide against prejudice: education.
Opportunistic infection as a cause of transient viremia in chronically infected HIV patients under treatment with HAART.

When highly active antiretroviral therapy is administered for long periods of time to HIV-1 infected patients, most patients achieve viral loads that are “undetectable” by standard assay (i.e., HIV-1 RNA < 50 copies/ml). Yet despite exhibiting sustained viral loads below the level of detection, a number of these patients experience unexplained episodes of transient viremia or viral “blips”. We propose here that transient activation of the immune system by opportunistic infection may explain these episodes of viremia. Indeed, immune activation by opportunistic infection may spur HIV replication, replenish viral reservoirs and contribute to accelerated disease progression. In order to investigate the effects of intercurrent infection on chronically infected HIV patients under treatment with highly active antiretroviral therapy (HAART), we extend a simple dynamic model of the effects of vaccination on HIV infection [Jones, L.E., Perelson, A.S., 2002. Modeling the effects of vaccination on chronically infected HIV-positive patients. JAIDS 31, 369–377] to include growing pathogens. We then propose a more realistic model for immune cell expansion in the presence of pathogen, and include this in a set of competing models that allow low baseline viral loads in the presence of drug treatment. Programmed expansion of immune cells upon exposure to antigen is a feature not previously included in HIV models, and one that is especially important to consider when simulating an immune response to opportunistic infection. Using these models we show that viral blips with realistic duration and amplitude can be generated by intercurrent infections in HAART treated patients.
Pragmatic characteristics of patient-reported outcome measures are important for use in clinical practice

Abstract Objectives Measures for assessing patient-reported outcomes (PROs) that may have initially been developed for research are increasingly being recommended for use in clinical practice as well. Although psychometric rigor is essential, this article focuses on pragmatic characteristics of PROs that may enhance uptake into clinical practice. Study Design and Setting Three sources were drawn on in identifying pragmatic criteria for PROs: (1) selected literature review including recommendations by other expert groups; (2) key features of several model public domain PROs; and (3) the authors' experience in developing practical PROs. Results Eight characteristics of a practical PRO include: (1) actionability (i.e., scores guide diagnostic or therapeutic actions/decision making); (2) appropriateness for the relevant clinical setting; (3) universality (i.e., for screening, severity assessment, and monitoring across multiple conditions); (4) self-administration; (5) item features (number of items and bundling issues); (6) response options (option number and dimensions, uniform vs. varying options, time frame, intervals between options); (7) scoring (simplicity and interpretability); and (8) accessibility (nonproprietary, downloadable, available in different languages and for vulnerable groups, and incorporated into electronic health records). Conclusion Balancing psychometric and pragmatic factors in the development of PROs is important for accelerating the incorporation of PROs into clinical practice.
Ruthenium-catalyzed tandem olefin metathesis-oxidations.

The utility of Grubbs' 2nd generation metathesis catalyst has been expanded by the development of two tandem olefin metathesis/oxidation protocols. These ruthenium-catalyzed processes provide cis-diols or α-hydroxy ketones from simple olefinic starting materials.
Microlensing Evidence That a Type 1 Quasar is Viewed Face-On

Using a microlensing analysis of 11 years of OGLE V-band photometry of the four image gravitational lens Q2237+0305, we measure the inclination i of the accretion disk to be cos i> 0.66 at 68% confidence. Very edge on (cos i< 0.39) solutions are ruled out at 95% confidence. We measure theV-band radius of the accretion disk, defined by the radius where the temperature matches the monitoring band photon emission, to be RV = 5.8 +3.8 −2.3 × 10 15 cm assuming a simple thin disk model and including the uncertainties in its inclination. The projected radiating area of the disk remains too large to be consistent with the observed flux for a T ∝ R −3/4 thin disk temperature profile. There is no strong correlation between the direction of motion (peculiar velocity) of the lens galaxy and the orientation of the disk.
Sleep and Anxiety Disorders

Sleep disturbances are commonly associated with anxiety disorders, particularly generalized anxiety disorder, panic disorder, and posttraumatic stress disorder. Core features of panic disorder and posttraumatic stress disorder occur in relation to sleep (sleep panic attacks, re-experiencing nightmares). These sleep episodes can usually be distinguished from primary sleep disorders on clinical grounds. Such conditions may coexist, however, and anxiety symptoms seem to benefit from treatment of sleep respiratory conditions. Established treatments for anxiety disorders and insomnia have many overlapping components; however, optimal sequencing and integration of the approaches is presently inadequately investigated.
Analysis of energy efficiency in fading channels under QoS constraints

Energy efficiency in fading channels in the presence of Quality of Service (QoS) constraints is studied. Effective capacity, which provides the maximum arrival rate that a wireless channel can sustain while satisfying statistical QoS constraints, is considered. Spectral efficiency-bit energy tradeoff is analyzed in the low-power and wideband regimes by employing the effective capacity formulation, rather than the Shannon capacity. Through this analysis, energy requirements under QoS constraints are identified. The analysis is conducted under two assumptions: perfect channel side information (CSI) available only at the receiver and perfect CSI available at both the receiver and transmitter. In particular, it is shown in the low-power regime that the minimum bit energy required under QoS constraints is the same as that attained when there are no such limitations. However, this performance is achieved as the transmitted power vanishes. Through the wideband slope analysis, the increased energy requirements at low but nonzero power levels in the presence of QoS constraints are determined. A similar analysis is also conducted in the wideband regime. The minimum bit energy and wideband slope expressions are obtained. In this regime, the required bit energy levels are found to be strictly greater than those achieved when Shannon capacity is considered. Overall, a characterization of the energy-bandwidth-delay tradeoff is provided.
A nonparametric analysis of income convergence across the US states

Abstract In this paper I apply the nonparametric methods proposed by Quah to data on US state relative income levels. In contrast to Quah’s results using cross-country data I find no evidence of polarization in the cross-state income distribution. The long-run density implied by the estimates is strongly unimodal. This finding is consistent with the results of previous analyses of convergence in state income levels using other methods.
Synthesis of 4-substituted homoallylic alcohols via a one-pot tandem Lewis-acid catalyzed crotylboration-[3,3]-sigmatropic rearrangement

Crotylboration of aldehydes with E- or Z-crotylboronates in the presence of catalytic amounts of indium triflate provides the corresponding 4-substituted homoallylic alcohols.
Chemical approaches to the investigation of cellular systems

Biochemistry in the context of a living cell or organism is complicated by many variables such as supramolecular organization, cytoplasmic viscosity, and substrate heterogeneity. While these variables are easily excluded or avoided in reconstituted systems, they must be dealt with in cellular environments. New developments have allowed researchers to begin probing the inner workings of the cell to gain new insight into cell function and metabolism. Advances in cellular imaging and in small molecule-controlled gene expression, signal transduction and cell surface modification are discussed in this review. These techniques have permitted the study of molecular components within the context of living cells.
Modeling Total Solar Irradiance Variations Using Automated Classification Software on Mount Wilson Data

We present the results using the AutoClass analysis application available at NASA/Ames Intelligent Systems Div. (2002) which is a Bayesian, finite mixture model classification system developed by Cheeseman and Stutz (1996). We apply this system to Mount Wilson Solar Observatory (MWO) intensity and magnetogram images and classify individual pixels on the solar surface to calculate daily indices that are then correlated with total solar irradiance (TSI) to yield a set of regression coefficients. This approach allows us to model the TSI with a correlation of better than 0.96 for the period 1996 to 2007. These regression coefficients applied to classified pixels on the observed solar surface allow the construction of images of the Sun as it would be seen by TSI measuring instruments like the Solar Bolometric Imager recently flown by Foukal et al. (Astrophys. J. 611, L57, 2004). As a consequence of the very high correlation we achieve in reproducing the TSI record, our approach holds out the possibility of creating an on-going, accurate, independent estimate of TSI variations from ground-based observations which could be used to compare, and identify the sources of disagreement among, TSI observations from the various satellite instruments and to fill in gaps in the satellite record. Further, our spatially-resolved images should assist in characterizing the particular solar surface regions associated with TSI variations. Also, since the particular set of MWO data on which this analysis is based is available on a daily basis back to at least 1985, and on an intermittent basis before then, it will be possible to estimate the TSI emission due to identified solar surface features at several solar minima to constrain the role surface magnetic effects have on long-term trends in solar energy output.
Active versus Passive Choice: Evidence from a Public Health Care Redesign:

Abstract This research examines how people choose among different public health insurance plans and assesses the factors that influence their choice. The authors explore two types of choice: active choice, in which consumers explicitly choose a plan, and passive/no choice, in which consumers take no action in choosing their plan. Using administrative and survey data for a sample of Medicaid recipients from a state that recently redesigned its Medicaid program, the authors identify what drives consumers' choices using constructs loosely framed by classic motivation, opportunity, and ability models. The results show that when consumers engage in active decision making, there are few barriers to selecting a wellness-based health plan with greater prescription coverage. In addition, the findings suggest that it is important for informed people, such as health care professionals, to be involved in plan choice. Unexpectedly, Medicaid recipients who rely on word-of-mouth communication tend to avoid active choice.
Inductance Compensation of Multiple Capacitors with Application to Common- and Differential-Mode Filters

Capacitor parasitic inductance often limits the high-frequency performance of Electromagnetic Interference (EMI) filters in both common- and differential-mode filtering domains. However, these limitations can be overcome through the use of specially-coupled magnetic windings that effectively nullify the capacitor parasitic inductance. This document explores the use of a single coupled magnetic winding to provide inductance compensation for multiple capacitors (e.g. both differential- and common-mode capacitors) simultaneously, reducing the number of coils previously required. The substantial advantages of this method are illustrated both in a proof-of-concept test circuit and in an improved version of an existing EMI filter. The coupling between multiple inductance compensation windings in a single filter enclosure is also investigated.
Reduction of Carbonyl Compounds with Chiral Oxazaborolidine Catalysts: A New Paradigm for Enantioselective Catalysis and a Powerful New Synthetic Method.

High enantioselectivity can be achieved when chiral oxazaborolidines are used as catalysts in the reduction of ketones by borane. In the transition state on the way to the complex chiral compounds, the two reactants are activated and held in close proximity by the catalyst, as shown below.
Time Lag Effect

The term time lag effect refers to the delay between the time of an intervention or exposure onset, such as the date on which a person begins smoking cigarettes, and the subsequent development of a health outcome, such as the diagnosis of lung cancer. Keywords: time lag effect; latent period
The Cost of Uncertainty about the Timing of Social Security Reform

Abstract We develop a model to study optimal decision making in the face of uncertainty about the timing and structure of a future event. The model is used to study optimal decision making and welfare when individuals face uncertainty about when and how Social Security will be reformed. For young individuals with many years to optimally hedge the risks that they face, the welfare cost of uncertainty about the timing and structure of reform is just a few basis points of total lifetime consumption. In contrast, the cost of reform uncertainty can be greater than 1% of total lifetime consumption for individuals close to retirement, even if they have saved optimally up to that point. Finally, the cost is significantly higher still for those who do not save optimally to hedge these risks.
A multifaceted analysis of HIV-1 protease multidrug resistance phenotypes

Great strides have been made in the effective treatment of HIV-1 with the development of second-generation protease inhibitors (PIs) that are effective against historically multi-PI-resistant HIV-1 variants. Nevertheless, mutation patterns that confer decreasing susceptibility to available PIs continue to arise within the population. Understanding the phenotypic and genotypic patterns responsible for multi-PI resistance is necessary for developing PIs that are active against clinically-relevant PI-resistant HIV-1 variants. In this work, we use globally optimal integer programming-based clustering techniques to elucidate multi-PI phenotypic resistance patterns using a data set of 398 HIV-1 protease sequences that have each been phenotyped for susceptibility toward the nine clinically-approved HIV-1 PIs. We validate the information content of the clusters by evaluating their ability to predict the level of decreased susceptibility to each of the available PIs using a cross validation procedure. We demonstrate the finding that as a result of phenotypic cross resistance, the considered clinical HIV-1 protease isolates are confined to ~6% or less of the clinically-relevant phenotypic space. Clustering and feature selection methods are used to find representative sequences and mutations for major resistance phenotypes to elucidate their genotypic signatures. We show that phenotypic similarity does not imply genotypic similarity, that different PI-resistance mutation patterns can give rise to HIV-1 isolates with similar phenotypic profiles. Rather than characterizing HIV-1 susceptibility toward each PI individually, our study offers a unique perspective on the phenomenon of PI class resistance by uncovering major multidrug-resistant phenotypic patterns and their often diverse genotypic determinants, providing a methodology that can be applied to understand clinically-relevant phenotypic patterns to aid in the design of novel inhibitors that target other rapidly evolving molecular targets as well.
A two‐fluid method for ambipolar diffusion

We present a semi-implicit method for isothermal two-fluid ion–neutral ambipolar drift that is second-order accurate in space and time. The method has been implemented in the riemann code for astrophysical fluid dynamics. We present four test problems that show the method works and correctly tracks the propagation of magnetohydrodynamic (MHD) waves and the structure of two-fluid C-shocks. The accurate propagation of MHD waves in the two-fluid approximation is shown to be a stringent test of the algorithm. We demonstrate that highly accurate methods are required in order to properly capture the MHD wave behaviour in the presence of ion–neutral friction.
Comparing structurally different views of a VLSI design

In large VLSI design projects, it is desirable to compare alternate views that use different hierarchies. However, existing techniques either require essentially identical hierarchies (which is sometimes an unacceptable restriction) or must flatten to remove the differences (which may be very costly). A new technique, informed comparison, has neither of these shortcomings. First, hierarchy transformations are applied to reconcile the structures of the views: then a hierarchical base comparison finishes the task. The reconciliation is guided by a small amount of additional design information: the intended relationship between the hierarchies of the views. Some qualities of informed comparison depend on the reconciliation repertoire and the base comparison. Two examples are studied. >
Expectations-driven spatial fluctuations

I develop a dynamic spatial model with monopolistic competition, increasing returns and labor mobility. Even when shocks to preferences or technology are absent, rational expectations equilibria characterized by stationary random fluctuations in the spatial allocation of resources are shown to exist. Such fluctuations result from the interaction between forward-looking location decisions and the agglomeration/congestion economies implied by the assumptions on market structure and preferences. Welfare losses result from the unnecessary randomness of equilibrium allocations along such equilibria.
Vehicle autonomy and intelligent control: Where are we and what lies ahead?

While a concise and universally accepted definition of intelligent control is elusive, the objective of enhancing the autonomous capabilities of vehicles can be practically considered along various fronts. Over recent decades, increasingly capable autonomous vehicles have been designed, developed, and demonstrated. Control theory and its application have played critical roles in these advancements. This talk will consider recent advances in the autonomous capabilities of vehicles, the role of control theory in achieving those advances, and potential directions for further enhancements in vehicle autonomy and intelligence.
Effect of propranolol on sympathetically mediated leg vasoconstriction in humans

Sympatho-excitatory manoeuvres are used to study vascular responsiveness in humans, but it is unclear if circulating adrenaline attenuates peripheral vasoconstriction during these manoeuvres. We hypothesized that vasoconstrictor responses to three manoeuvres (neck pressure, unilateral thigh-cuff release and isometric handgrip) would be greater after the administration of the beta-adrenergic blocker propranolol. Seven men and six women underwent these manoeuvres while beat-by-beat arterial pressure (finger photoplethysmography), femoral mean blood velocity (Doppler ultrasound) and femoral artery diameter (edge-detection software) were measured. Femoral vascular conductance was calculated as flow/pressure. Propranolol had no effect on baseline femoral vascular conductance (P > 0.05). As a result of neck pressure, femoral vascular conductance was reduced 23.9 +/- 3.5% before vs. 33.2 +/- 3.2% after infusion of propranolol (P = 0.033). After thigh-cuff release, femoral vascular conductance declined 50.2 +/- 5.8% before vs. 57.4 +/- 9.6% after propranolol infusion (P = 0.496). During handgrip, femoral vascular conductance was reduced 47.2 +/- 9.6% before vs. 55.2 +/- 9.2% after propranolol administration (P = 0.447). After handgrip, women had a greater rise in conductance than men (women: 153 +/- 16.2%; men: 36.4 +/- 10.6%; P < 0.001), which was blunted by 54.8% by propranolol (P < 0.001 vs. control), but unaffected by propranolol in men (P = 0.355 vs. control). The finding that beta-adrenergic receptor-mediated vasodilatation minimally affects vascular responses to these sympatho-excitatory manoeuvres reinforces their utility in the investigation of sympathetic vascular regulation in humans. Interestingly, post-handgrip hyperaemia is greater in women than men and is, in part, beta-adrenergic receptor mediated.
An Enantioselective Synthesis of 2-Aryl Cycloalkanones by Sc-Catalyzed Carbon Insertion

Current methods for asymmetric α-arylation require blocking groups to prevent reaction at the α′-carbon, basic conditions that promote racemization, or multistep synthesis. This work records the first catalytic enantioselective examples of the diazoalkane-carbonyl homologation reaction. Medium ring 2-aryl ketones are prepared in one step in up to 98:2 er and 99% yield from the unsubstituted lower homologue by Sc-catalyzed aryldiazomethyl insertion with simple bis- and tris(oxazoline) ligands.
Contagion Effects of Dividend Reduction or Omission Announcements in the Electric Utility Industry

This study examines the contagion effects of dividend reduction or omission announcements in the electric utility industry. Using a series of ten electric utility dividend announcements covering the period 1979–1991, I analyze differences in contagion reactions across utilities. I find the strength of the contagion reaction is significantly related to utility size, average dividend yield, debt ratio, market-to-book ratio, cash flow, and Altman's Z-score. There is also evidence of a flight to quality, including a preference for utilities operating in more favorable regulatory environments.
Multi-functional foot use during running in the zebra-tailed lizard (Callisaurus draconoides).

SUMMARY A diversity of animals that run on solid, level, flat, non-slip surfaces appear to bounce on their legs; elastic elements in the limbs can store and return energy during each step. The mechanics and energetics of running in natural terrain, particularly on surfaces that can yield and flow under stress, is less understood. The zebra-tailed lizard ( Callisaurus draconoides ), a small desert generalist with a large, elongate, tendinous hind foot, runs rapidly across a variety of natural substrates. We use high-speed video to obtain detailed three-dimensional running kinematics on solid and granular surfaces to reveal how leg, foot and substrate mechanics contribute to its high locomotor performance. Running at ~10 body lengths s −1 (~1 m s −1 ), the center of mass oscillates like a spring-mass system on both substrates, with only 15% reduction in stride length on the granular surface. On the solid surface, a strut-spring model of the hind limb reveals that the hind foot saves ~40% of the mechanical work needed per step, significant for the lizard9s small size. On the granular surface, a penetration force model and hypothesized subsurface foot rotation indicates that the hind foot paddles through fluidized granular medium, and that the energy lost per step during irreversible deformation of the substrate does not differ from the reduction in the mechanical energy of the center of mass. The upper hind leg muscles must perform three times as much mechanical work on the granular surface as on the solid surface to compensate for the greater energy lost within the foot and to the substrate.
Projection-based spatially adaptive reconstruction of block-transform compressed images

At the present time, block-transform coding is probably the most popular approach for image compression. For this approach, the compressed images are decoded using only the transmitted transform data. We formulate image decoding as an image recovery problem. According to this approach, the decoded image is reconstructed using not only the transmitted data but, in addition, the prior knowledge that images before compression do not display between-block discontinuities. A spatially adaptive image recovery algorithm is proposed based on the theory of projections onto convex sets. Apart from the data constraint set, this algorithm uses another new constraint set that enforces between-block smoothness. The novelty of this set is that it captures both the local statistical properties of the image and the human perceptual characteristics. A simplified spatially adaptive recovery algorithm is also proposed, and the analysis of its computational complexity is presented. Numerical experiments are shown that demonstrate that the proposed algorithms work better than both the JPEG deblocking recommendation and our previous projection-based image decoding approach. >
Does Internal Audit Function Quality Deter Management Misconduct

ABSTRACT: Standard-setters believe high-quality internal audit functions (IAFs) serve as a key resource to audit committees for monitoring senior management. However, regulators do not enforce IAF quality or require disclosures relating to IAF quality, which is in stark contrast to regulatory requirements placed on boards, audit committees, and external auditors. Using proprietary data, I find that a composite measure of IAF quality is negatively associated with the likelihood of management misconduct even after controlling for board, audit committee, and external auditor quality. This result is robust to a variety of other specifications, including controlling for internal control quality and separate estimation during the pre- and post-SOX time periods. A difference-in-differences analysis indicates that misconduct firms have low IAF quality and competence during misconduct years and improve IAF quality and competence in the post-misconduct years. These findings suggest that regulators, audit committees...
Capacity/Storage Tradeoff in High-Dimensional Identification Systems

The asymptotic tradeoff between the number of distinguishable objects and the necessary storage space (or equivalently, the search complexity) in an identification system is investigated. In the discussed scenario, high-dimensional (and noisy) feature vectors extracted from objects are first compressed and then enrolled in the database. When the user submits a random query object, the extracted noisy feature vector is compared against the compressed entries, one of which is output as the identified object. The first result this paper presents is a complete single-letter characterization of achievable storage and identification rates (measured in bits per feature dimension) subject to vanishing probability of identification error as the dimensionality of feature vectors becomes very large. This single-letter characterization is then extended for a multistage system whereby depending on the number of entries, the identification is performed by utilizing part or all of the recorded bits in the database. Finally, it is shown that a necessary and sufficient condition for a two-stage system to achieve single-stage capacities at each stage is Markovity of the optimal test channels.
Cationic, Two-Coordinate Gold π Complexes

Cationic, two-coordinate gold π complexes that contain a phosphine or N-heterocyclic supporting ligand have attracted considerable attention recently owing to the potential relevance of these species as intermediates in the gold-catalyzed functionalization of CC multiple bonds. Although neutral two-coordinate gold π complexes have been known for over 40 years, examples of the cationic two-coordinate gold(I) π complexes germane to catalysis remained undocumented prior to 2006. This situation has changed dramatically in recent years and well-defined examples of two-coordinate, cationic gold π complexes containing alkene, alkyne, diene, allene, and enol ether ligands have been documented. This Minireview highlights this recent work with a focus on the structure, bonding, and ligand exchange behavior of these complexes.
The Prognostic Value of Quantitative Bone Scan in Knee Osteochondritis Dissecans A Preliminary Experience

We reviewed the records of 12 patients ages 9 to 16 years with knee osteochondritis dissecans. All patients had clinical histories and examinations, four radiographic views of the knee, and technetium-99m diphosphonate quantitative bone scans. Scan results (symmetric, increased, or decreased activity), clinical course, healing time, and final outcome were correlated to determine the prognostic value of the scan. We divided the patients into those with open physes (distal femoral and proximal tibial) and those with closed physes. Four of the six patients with open physes had increased activity on the bone scan. All four of these knees healed with nonsurgical treatment. The other two patients had decreased activity on bone scan, and both required surgical treatment after nonsurgical treatment failed. Of the six patients with closed physes, all had increased activity on the bone scan, but only two patients had healing of the osteochondral lesion without surgery. Quantitative bone scanning had a 100% predictive value for the prognosis in osteochondritis dissecans patients with open physes, but for those with closed physes the predictive value was less. Because the natural history in the adolescent group is less predictable, it is in this group that the quantitative scan would be most helpful. In this small group of patients, quantitative bone scanning had limited prognostic value.
Is your phylogeny informative? Measuring the power of comparative methods

Phylogenetic comparative methods may fail to produce meaningful results when either the underlying model is inappropriate or the data contain insufficient information to inform the inference. The ability to measure the statistical power of these methods has become crucial to ensure that data quantity keeps pace with growing model complexity. Through simulations, we show that commonly applied model choice methods based on information criteria can have remarkably high error rates; this can be a problem because methods to estimate the uncertainty or power are not widely known or applied. Furthermore, the power of comparative methods can depend significantly on the structure of the data. We describe a Monte Carlo-based method which addresses both of these challenges, and show how this approach both quantifies and substantially reduces errors relative to information criteria. The method also produces meaningful confidence intervals for model parameters. We illustrate how the power to distinguish different models, such as varying levels of selection, varies both with number of taxa and structure of the phylogeny. We provide an open-source implementation in the pmc ("Phylogenetic Monte Carlo") package for the R programming language. We hope such power analysis becomes a routine part of model comparison in comparative methods.
Vernon Smith's Insomnia and the Dawn of Economics as Experimental Science

This discussion of Vernon Smith's body of work in experimental economics was written for the Scandinavian Journal of Economics in commemoration of Vernon's Nobel Prize. It will appear in Spring 2003.
Polynomial Bridgeland stability conditions and the large volume limit

We introduce the notion of a polynomial stability condition, generalizing Bridgeland stability conditions on triangulated categories. We construct and study a family of polynomial stability conditions for any normal projective variety. This family includes both Simpson-stability and large volume limits of Bridgeland stability conditions. We show that the PT/DT‐correspondence relating stable pairs to Donaldson‐Thomas invariants (conjectured by Pandharipande and Thomas) can be understood as a wallcrossing in our family of polynomial stability conditions. Similarly, we show that the relation between stable pairs and invariants of one-dimensional torsion sheaves (proven recently by the same authors) is a wall-crossing formula. 14F05, 18E30; 14J32, 14D20, 14N35
REGULATION OF THE HYDROGEN ION CONCENTRATION AND ITS RELATION TO METABOLISM AND RESPIRATION IN THE STARFISH

The normal reaction of the cœlomic fluid in Patiria miniata and Asterias ochraceus is pH 7.6, and of the caeca, 6.7, compared with sea water at 8.3, all without salt error correction. A medium at pH 6.7–7.0 is optimum for the caeca for ciliary survival and digestion of protein, and is maintained by carbon dioxide production. The optimum pH found for carbon dioxide production is a true one for the effect of hydrogen ion concentration on the tissue. It does not represent an elimination gradient for carbon dioxide. Because the normal excised caeca maintain a definite hydrogen ion concentration and change their internal environment toward that as an optimum during life, there exists a regulatory process which is an important vital function.
Formalization of UML Composition in OCL

With the increasing use of design models during the development process, developers now face a daunting task to maintain consistency between the design models and their implementation. Consistency maintenance is particularly challenging when a design model language introduces constructs that have no direct counterpart in programming languages. For example, the UML composition, an important relationship in software development, reflects some important principles in software engineering such as encapsulation. Unfortunately, affected by the ownership model, existing approaches supporting UML composition require the non-accessibility property. However, the composition in the UML specification does not support the ownership model. So, in this paper we present a UML composition formalization using the Object Constraint Language (OCL) that strictly adheres to the UML specification.
Metaphoric optical computing of fluid dynamics

Nonlinear optical propagation is recast in a comprehensive hydrodynamical formulation. The split-step method is proposed to combine optical devices as a configurable system that computes fluid dynamics, tremendously faster than even the fluid itself.