cssi/SciSciGPT-SciSciNet huggingface dataset:
Divided Loyalists or Conditional Cooperators? Creating Consensus About Cooperation in Multiple Simultaneous Social Dilemmas

The current social dilemma literature lacks theoretical consensus regarding how individuals behave when facing multiple simultaneous social dilemmas. The divided-loyalty hypothesis, from organizational theory, predicts that cooperation will decline as individuals experience multiple social dilemmas with different compared to the same group members. The conditional-cooperation hypothesis, from behavioral economics, predicts that cooperation will increase as individuals experience multiple social dilemmas with different compared to the same group members. We employ a laboratory experiment to create consensus between these literatures and find support for the conditional-cooperation hypothesis. The positive effect of interacting with different group members comes from participants having an opportunity to shift their cooperative behavior from the less cooperative to the more cooperative group.
Modified-source gravity and cosmological structure formation

One way to account for the acceleration of the universe is to modify general relativity, rather than introducing dark energy. Typically, such modifications introduce new degrees of freedom. It is interesting to consider models with no new degrees of freedom, but with a modified dependence on the conventional energy-momentum tensor; the Palatini formulation of f(R) theories is one example. Such theories offer an interesting testing ground for investigations of cosmological modified gravity. In this paper we study the evolution of structure in these 'modified-source gravity' (MSG) theories. In the linear regime, density perturbations exhibit scale dependent runaway growth at late times and, in particular, a mode of a given wavenumber goes nonlinear at a higher redshift than in the standard lambda-cold dark matter (?CDM) model. We discuss the implications of this behaviour and why there are reasons to expect that the growth will be cut off in the nonlinear regime. Assuming that this holds in a full nonlinear analysis, we briefly describe how upcoming measurements may probe the differences between the modified theory and the standard ?CDM model.
Group velocity delay spectroscopy technique for industrial monitoring of electron-beam-induced vapors

Spectroscopic techniques are ideal for characterization and process control of electron beam generated beam generated vapor plumes. Absorption based techniques work well for a wide variety of applications, but are difficult to apply to optically dense or opaque vapor plumes. We describe an approach for monitoring optically dense vapor plumes that is based on measuring the group velocity delay of a laser beam near an optical transition to determine the vapor density. This technique has a larger dynamic range than absorption environment. Aluminum as chosen because of its prevalence in high performance aircraft alloys. In these applications, composition control of the alloy constituents is critical to the deposition process. Data is presented demonstrating the superior dynamic range of the measurement. In addition, preliminary data demonstrating aluminum vapor rate control in an electron beam evaporator is presented. Alternative applications where this technique could be useful are discussed.
Spatial Decomposition of Segregation Indices: A Framework Toward Measuring Segregation at Multiple Levels

Segregation measures based upon data gathered at different geographical levels cannot provide consistent results because of the scale effect under the Modifiable Areal Unit Problem (MAUP) umbrella. This paper proposes a framework, which decomposes segregation attributable to different geographical levels, to conceptually link segregation values obtained from multiple geographical levels together such that differences in segregation values among levels are accounted for. Using two different indices, the dissimilarity index D and the diversity index H, this paper illustrates the decomposition methods specific to these indices. When these indices are decomposed, local measures of segregation pertaining to multiple geographical levels are computed. These local segregation measures indicate the levels of segregation contributed by the local units and the regional units to the entire study area.
Rebate rules in threshold public good provision

Abstract This paper considers how six alternative rebate rules affect voluntary contributions in a threshold public-good experiment. The rules differ by (1) whether an individual can receive a proportional rebate of excess contributions, a winner-takes-all of any excess contributions, or a full rebate of one's contribution in the event the public good is provided and excess contributions exist, and (2) whether the probability of receiving a rebate is proportional to an individual's contribution relative to total contributions or is a simple uniform probability distribution set by the number of contributors. The paper adds to the existing experimental economics literature on threshold public goods by investigating both aggregate and individual demand revelation under the winner-take-all and random full-rebate rules. Half of the rules (proportional rebate, winner-take-all with uniform probability among all group members , and random full-rebate with uniform probability) provide total contributions that nearly equal total benefits, while the rest (winner-take-all with proportional probability, winner-take-all with uniform probability among contributors only , and random full-rebate with proportional probability) exceed benefits by over 30%. Only the proportional rebate rule is found to achieve both aggregate and individual demand revelation. Our experimental results have implications for both fundraisers and valuation practitioners.
Dynamic multi-vehicle routing with multiple classes of demands

In this paper we study a dynamic vehicle routing problem in which there are multiple vehicles and multiple classes of demands. Demands of each class arrive in the environment randomly over time and require a random amount of on-site service that is characteristic of the class. To service a demand, one of the vehicles must travel to the demand location and remain there for the required on-site service time. The quality of service provided to each class is given by the expected delay between the arrival of a demand in the class, and that demand's service completion. The goal is to design a routing policy for the service vehicles which minimizes a convex combination of the delays for each class. First, we provide a lower bound on the achievable values of the convex combination of delays. Then, we propose a novel routing policy and analyze its performance under heavy load conditions (i.e., when the fraction of time the service vehicles spend performing on-site service approaches one). The policy performs within a constant factor of the lower bound (and thus the optimal), where the constant depends only on the number of classes, and is independent of the number of vehicles, the arrival rates of demands, the on-site service times, and the convex combination coefficients.
The Design of Nonlinear Multivariable Control Systems From State Dependent Linear Models

A technique is presented for the design of a continuous nonlinear multivariable control algorithm from a set of simple, linear control models. The coefficients of the linear control models are dependent on the steady state operating point. The technique makes use of line integration and the method of least squares to bridge the gap between the sets of linear coefficients and the continuous nonlinear functions of the nonlinear algorithm. In general, the nonlinear control algorithm is nonunique. The method permits the extension of linear design procedures to the design of nonlinear control systems. It can be used to design a control system for a nonlinear process to maintain the dynamics of the entire system invariant with respect to changes in the operating point.
Ridership Accuracy and Transit Formula Grants

The accuracy of annual unlinked passenger trips reported to the National Transit Database (NTD) at the agency level is examined by using a two-step approach. The first step compares ridership reported to the American Public Transportation Association (APTA) with ridership reported to NTD. NTD ridership can be as high as 50% more than APTA rider-ship, and such significant positive deviation exists persistently over time across many agencies. The second step explores potential sources of these deviations by examining their components. Random errors, including both sampling errors and some of the nonsampling errors, do not help explain these one-sided deviations, nor do occasional annual adjustments, such as special-events ridership in the NTD ridership. Much of this deviation appears to be attributable to systematic nonsampling sources that result from undercounting in direct counts, from unintentional biases in procedures, or perhaps from intentional manipulation. Although mechanisms and incentives exist f...
Modal Analysis to Accommodate Slap in Linear Structures

The generalized momentum balance (GMB) methods, explored chiefly by Shabana and his co-workers, treat slap or collision in linear structures as sequences of impulses, thereby maintaining the linearity of the structures throughout. Further, such linear analysis is facilitated by modal representation of the structures. These methods are discussed here and extended. Simulations on a simple two-rod problem demonstrate how this modal impulse approximation affects the system both directly after each impulse as well as over the entire collision. Furthermore, these simulations illustrate how the GMB results differ from the exact solution and how mitigation of these artifacts is achieved. Another modal method discussed in this paper is the idea of imposing piecewise constant forces over short, yet finite, time intervals during contact. The derivation of this method is substantially different than that of the GMB method, yet the numerical results show similar behavior, adding credence to both models. Finally, a novel method combining these two approaches is introduced. The new method produces physically reasonable results that are numerically very close to the exact solution of the collision of two rods. This approach avoids most of the non physical, numerical artifacts of interpenetration or chatter present in the first two methods.
The Wealth of Cities: Agglomeration Economies and Spatial Equilibrium in the United States

*Empirical research on cities starts with a spatial equilibrium condition: workers and fi rms are assumed to be indifferent across space. This condition implies that research on cities is different from research on countries, and that work on places within countries needs to consider population, income, and housing prices simultaneously. Housing supply elasticity will determine whether urban success reveals itself in the form of more people or higher incomes. Urban economists generally accept the existence of agglomeration economies, which exist when productivity rises with density, but estimating the magnitude of those economies is diffi cult. Some manufacturing fi rms cluster to reduce the costs of moving goods, but this force no longer appears to be important in driving urban success. Instead, modern cities are far more dependent on the role that density can play in speeding the fl ow of ideas. Finally, urban economics has some insights to offer related topics such as growth theory, national income accounts, public economics, and housing prices. (JEL R11, R23, R31, R32)
Pilot Intervention to Enhance Sexual Rehabilitation for Couples After Treatment for Localized Prostate Carcinoma

BACKGROUND The majority of prostate carcinoma survivors experience enduring sexual difficulties and associated distress in the years after definitive treatment. A counseling intervention aimed at improving levels of sexual satisfaction and increasing successful utilization of medical treatment for erectile dysfunction (ED) was developed and pilot-tested for both the survivor of prostate carcinoma and his partner. METHODS All male participants were 3-month to 5-year survivors of localized prostate carcinoma who had been treated with radical prostatectomy or radiation therapy, and were married or in a committed relationship. Couples were randomized to attend four sessions of counseling together or to have the man attend alone. In both groups, partners completed behavioral homework. The sessions included education on prostate carcinoma and sexual function and options to treat ED as well as sexual communication and stimulation skills. Standardized questionnaires at baseline, posttreatment, and at 3-month and 6-month follow-up assessed sexual function, marital adjustment, psychologic distress, and utilization of treatments for ED. RESULTS Fifty-one of 84 couples randomized to treatment completed the intervention (61%). Attendance by the partner did not affect outcomes. Participants completing the intervention demonstrated improvment in male overall distress (P < 0.01), male global sexual function (P < 0.0001), and female global sexual function (P < 0.05) at 3-month follow-up, but regression toward baseline was noted at 6-month follow-up. However, utilization of ED treatments increased from 31% at the time of study entry to 49% at the 6-month follow-up (P = 0.003). CONCLUSIONS The results of this brief pilot counseling intervention demonstrated significant gains in sexual function and satisfaction and increased utilization of treatments for ED. However, modifications are needed in future randomized trials to reduce the rate of premature termination and to improve long-term maintenance of gains. Cancer 2005. © 2005 American Cancer Society.
The HI properties and environment of Lyman-$\alpha$ absorbers

We present results from two projects in which we have used the HI 21cm emission line as a tracer of gas-rich galaxy populations in the vicinity of Lyman-� absorbers. In the first case, we examine the HI environment of SBS 1543+593, the nearest damped Lyman-� absorber. We use a VLA map of the region around this LSB galaxy which itself shows an extended HI disk to identify 3 gas rich neighbors within 185 kpc. While it is not clear whether we should expect local damped Lyman-� systems to reside in such gas-rich regions, we would expect this kind of environment to be more prevalent at higher redshifts where less of the gas is in the dense inner regions of galaxies or has been consumed by star formation. This local galaxy is the only system in which we can study the gaseous environment in this kind of detail. In the second case, we examine the HI environment surrounding 16 Lyman-� forest absorbers along 4 QSO sightlines. We do not detect any gas-rich galaxies at the absorber positions indicating that, at least down to our sensitivity limits, these absorption lines do not seem to be associated with galaxy halos. For half of the Lyman-� absorption systems there is a galaxy within 500 kpc, but for the other half there is not. In two cases there is no galaxy within 2 Mpc of the Lyman-�absorption systems indicating that absorbers do, in some cases, reside in voids.
Matching Between Heterogeneous Workers and Firms

A model of the labor market under search frictions is developed, where participants are heterogeneous with respect to their productivity types and the individual decision of which type of agents to match with is endogenized. Wages are negotiated, so that all gains from trade are exploited. This has important implications for the equilibrium outcomes. In particular, two applications are studied. It is observed that countries with high (low) unemployment tend to exhibit low (high) wage dispersion. And there is evidence showing that individual and …rm characteristics have more explanatory power for the French than for the American data. The model is able to replicate these two observations, underscoring the relevance of ¸ ¸
Working to Change the World: An Examination of One Child’s Social Activism

There is wide recognition that children’s lives are directly affected by inequitable practices in relation to aspects of identity such as gender, ethnicity, class, and citizenship. Yet, despite this acknowledgement, few scholars have explored how children are challenging inequities. This examination of the actions and stories of one-nine-year-old female addresses that silence. Data analysis illustrates the ways in which she was enacting social activist tenets. Also illuminated are the hurdles inherent to adult recognition of children’s activism. These findings underline the problematic role that deficit framings of children play in our understanding of their perspectives and capabilities.
Efficient and complete centralized multi-robot path planning

Multi-robot path planning is abstracted as the problem of computing a set of non-colliding paths on a graph for multiple robots. A naive search of the composite search space, although complete, has exponential complexity and becomes computationally prohibitive for problems with just a few robots. This paper proposes an efficient and complete algorithm for solving a general class of multi-robot path planning problems, specifically those where there are at most n-2 robots in a connected graph of n vertices. This paper provides a full proof of completeness. The algorithm employs two primitives: “push”, where a robot moves toward its goal until no progress can be made, and “swap”, that allows two robots to swap positions without altering the position of any other robot. Additionally, this paper provides a smoothing procedure for improving solution quality. Simulated experiments compare the proposed approach with several other centralized and decoupled planners, and show that the proposed technique improves computation time and solution quality, while scaling to problems with 100s of robots, solving them in under 5 seconds.
Performance Enhancement of a Composite Tilt-Rotor Using Aeroelastic Tailoring

An optimization technique is applied in an attempt to improve the performance of a tilt-rotor aircraft with composite blades that are enhanced by aeroelastic tailoring. The aeroelastic analysis is based on a published mixed variational formulation of the exact intrinsic equations of motion of beams, along with a finite-state dynamic inflow theory for the rotor. The composite rotor blade is modeled structurally as a composite box beam with nonstructural mass included. For optimization the design variables are blade twist, box dimensions and wall thicknesses, ply angles of the laminated walls, and nonstructural mass. The rotor is optimized using an objective function that is weighted equally between the figure of merit in hover and the axial efficiency in for ward flight. Constraints are considered on blade weight, autorotational inertia, geometry, and aeroelastic stability. The effects of all structural couplings on rotor performance are studied. Of all possible couplings, extension-twist coupling is found to be the most effective parameter to enhance performance. The effects of accounting for pretwist and thin- vs thick-walled theories in the blade cross-sectional analysis are discussed. Significant improvements in the objective function are shown to be possible even when optimizing only the extension-twist coupling of the rotor blade.
Reversal of chlordiazepoxide‐induced impairment in successive discrimination performance by RO 15‐1788

The effects of chiordiazepoxide (CDP) alone and in combination with Ro 15-1788 on the performance of a previously learned go-no go successive discrimination were studied in male Sprague-Dawley rats. CDP 10 mg/kg impaired discrimination performance in six sucessive sessions, with animals showing recovery in two post-drug sessions. The impairment in disrcimination performance was due to an increase in responding during no go (waiting) periods of the task. The benzodizepine (BDZ) receptor antagonist Ro 15-778 (5 and 10 mg/kg) reversed the impairment in discrimination performance in sessions 2-6 (but not 1) when co-administered with CDP. While the effectiveness of Ro 15-1788 was not dose-dependent, the reversal in discrimination impairment was due to a reduction in responding during no go periods of the task. These findings suggest that the impairment in discrimination performance produced by CDP is mediated by central BDZ receptor sites. When administered alone, Ro 15-1788 10 mg/kg (but not 5mg/kg) produced a mild BDZ-like impairment in discrimination performance and increase in a no go period responding. These findings suggest that Ro 15-1788 is not a neutral antagonist but has some intrinsic action of its own.
Automated Analysis and Synthesis of Block-Cipher Modes of Operation

Block ciphers such as AES are deterministic, keyed functions that operate on small, fixed-size blocks. Block-cipher modes of operation define a mechanism for probabilistic encryption of arbitrary length messages using any underlying block cipher. A mode of operation can be proven secure (say, against chosen-plaintext attacks) based on the assumption that the underlying block cipher is a pseudorandom function. Such proofs are complex and error-prone, however, and must be done from scratch whenever a new mode of operation is developed. We propose an automated approach for the security analysis of block-cipher modes of operation based on a "local" analysis of the steps carried out by the mode when handling a single message block. We model these steps as a directed, acyclic graph, with nodes corresponding to instructions and edges corresponding to intermediate values. We then introduce a set of labels and constraints on the edges, and prove a meta-theorem showing that any mode for which there exists a labeling of the edges satisfying these constraints is secure (against chosen-plaintext attacks). This allows us to reduce security of a given mode to a constraint-satisfaction problem, which in turn can be handled using an SMT solver. We couple our security-analysis tool with a routine that automatically generates viable modes, together, these allow us to synthesize hundreds of secure modes.
The Effect of Digital Sharing Technologies on Music Markets: A Survival Analysis of Albums on Ranking Charts

Recent technological and market forces have profoundly impacted the music industry. Emphasizing threats from peer-to-peer (P2P) technologies, the industry continues to seek sanctions against individuals who offer a significant number of songs for others to copy. Combining data on the performance of music albums on the Billboard charts with file sharing data from a popular network, we assess the impact of recent developments related to the music industry on survival of music albums on the charts and evaluate the specific impact of P2P sharing on an album's survival on the charts. In the post-P2P era, we find significantly reduced chart survival except for those albums that debut high on the charts. In addition, superstars and female artists continue to exhibit enhanced survival. Finally, we observe a narrowing of the advantage held by major labels. The second phase of our study isolates the impact of file sharing on album survival. We find that, although sharing does not hurt the survival of top-ranked albums, it does have a negative impact on low-ranked albums. These results point to increased risk from rapid information sharing for all but the “cream of the crop.”
Preferential Encapsulation and Stability of La3N Cluster in 80 Atom Cages: Experimental Synthesis and Computational Investigation of La3N@C79N

We report the synthesis and electronic stabilization of La3N@C79N. Unsuccessful efforts to encapsulate bulky La3N clusters in small C80 cages have been attributed to large ionic radii. The preferred species for La3N clusters in all-carbon cages is La3N@C96. A surprising finding is the synthesis of La3N@C79N, a new metallofullerene present in higher abundance than La3N@C96. This reduction in cage size from 96 to 80 atoms reflects the significance and role of electronic effects. To understand the geometric and electronic properties of this first metallic nitride azafullerene (M3N@C79N, M = La), density functional theory (DFT) investigations were performed on a number of isomers. Results indicate a preferred N-substitution at the 665 junction site on the cage in lieu of a 666 substitution. The relative stabilities of different isomers can be well reproduced by using the minimum distance between the metal atom and the nitrogen atom of the cage (RN′Mmin). Long RN′Mmin values indicate distant contacts between s...
GRace: a low-overhead mechanism for detecting data races in GPU programs

In recent years, GPUs have emerged as an extremely cost-effective means for achieving high performance. Many application developers, including those with no prior parallel programming experience, are now trying to scale their applications using GPUs. While languages like CUDA and OpenCL have eased GPU programming for non-graphical applications, they are still explicitly parallel languages. All parallel programmers, particularly the novices, need tools that can help ensuring the correctness of their programs. Like any multithreaded environment, data races on GPUs can severely affect the program reliability. Thus, tool support for detecting race conditions can significantly benefit GPU application developers. Existing approaches for detecting data races on CPUs or GPUs have one or more of the following limitations: 1) being illsuited for handling non-lock synchronization primitives on GPUs; 2) lacking of scalability due to the state explosion problem; 3) reporting many false positives because of simplified modeling; and/or 4) incurring prohibitive runtime and space overhead. In this paper, we propose GRace, a new mechanism for detecting races in GPU programs that combines static analysis with a carefully designed dynamic checker for logging and analyzing information at runtime. Our design utilizes GPUs memory hierarchy to log runtime data accesses efficiently. To improve the performance, GRace leverages static analysis to reduce the number of statements that need to be instrumented. Additionally, by exploiting the knowledge of thread scheduling and the execution model in the underlying GPUs, GRace can accurately detect data races with no false positives reported. Based on the above idea, we have built a prototype of GRace with two schemes, i.e., GRace-stmt and GRace-addr, for NVIDIA GPUs. Both schemes are integrated with the same static analysis. We have evaluated GRace-stmt and GRace-addr with three data race bugs in three GPU kernel functions and also have compared them with the existing approach, referred to as B-tool. Our experimental results show that both schemes of GRace are effective in detecting all evaluated cases with no false positives, whereas Btool reports many false positives for one evaluated case. On the one hand, GRace-addr incurs low runtime overhead, i.e., 22-116%, and low space overhead, i.e., 9-18MB, for the evaluated kernels. On the other hand, GRace-stmt offers more help in diagnosing data races with larger overhead.
Microporous porphyrin and metalloporphyrin materials

Abstract The diverse efforts to rationally construct microporous solids using porphyrins and metalloporphyrins as molecular building blocks are reviewed. Porphyrin-based molecular crystals, hydrogen-bonded networks, and metal ion coordination polymer networks are examined in detail. Recurring geometrical motifs observed in the structural frameworks of different porphyrinic solids are emphasized, and the influences of solvates and guest molecules are explored. Attempts to construct porphyrin–siloxane networks are also reviewed.
R-trees: a dynamic index structure for spatial searching

In order to handle spatial data efficiently, as required in computer aided design and geo-data applications, a database system needs an index mechanism that will help it retrieve data items quickly according to their spatial locations However, traditional indexing methods are not well suited to data objects of non-zero size located m multi-dimensional spaces In this paper we describe a dynamic index structure called an R-tree which meets this need, and give algorithms for searching and updating it. We present the results of a series of tests which indicate that the structure performs well, and conclude that it is useful for current database systems in spatial applications
Molecular Machines: How Motion and Other Functions of Living Organisms Can Result from Reversible Chemical Changes

Certain model proteins dramatically fold and become more ordered on raising the temperature. When the temperature is raised to drive folding and assembly, these model proteins can lift weights and perform work; they can produce motion. The temperature of warm-blooded animals, however, is kept constant. Therefore, motion cannot result from a change in temperature. In this case, a free energy change, caused, for example, by an increase in the concentration of a chemical, can lower the temperature at which the protein folding and assembly transition occurs from above to below physiological temperature. Raising the concentration of a chemical isothermally has indeed been shown to result in motion and the efficient performance of work. These model proteins and the mechanism they reveal provide insight into the molecular basis for diverse biological functions; they are models for the molecular machines that comprise the living organism, and they provide a new class of materials for both medical and nonmedical applications.
Video and image bayesian demosaicing with a two color image prior

The demosaicing process converts single-CCD color representations of one color channel per pixel into full per-pixel RGB. We introduce a Bayesian technique for demosaicing Bayer color filter array patterns that is based on a statistically-obtained two color per-pixel image prior. By modeling all local color behavior as a linear combination of two fully specified RGB triples, we avoid color fringing artifacts while preserving sharp edges. Our grid-less, floating-point pixel location architecture can process both single images and multiple images from video within the same framework, with multiple images providing denser color samples and therefore better color reproduction with reduced aliasing. An initial clustering is performed to determine the underlying local two color model surrounding each pixel. Using a product of Gaussians statistical model, the underlying linear blending ratio of the two representative colors at each pixel is estimated, while simultaneously providing noise reduction. Finally, we show that by sampling the image model at a finer resolution than the source images during reconstruction, our continuous demosaicing technique can super-resolve in a single step.
A study of netlist structure and placement efficiency

In this paper, we examine the relationship between netlist structure and the efficiency of placers measured in terms of quality and stability of results. We analyze three types of placers: analytic, simulated-annealing based, and partition based. We have tested these placers on industrial and synthetic benchmarks. Based on our observations and analyzes of experimental results, we draw several useful conclusions: 1) Various placers favor netlists with different structural characteristics; 2) placement efficiency correlates with interconnection complexity of the circuits; 3) global nets increase the effort to eliminate overlaps of cells and degrade the efficiency of analytic placers; and 4) global nets can improve placement stability of partition-based placers.
Mid-IR Observations and a Revised Time Delay for the Gravitational Lens System Quasar HE 1104–1805

The mid-IR flux ratios FA/FB = 2.84 ± 0.06 of the two images of the gravitationally lensed quasar HE 1104-1805 show no wavelength dependence to within 3% across 3.6-8.0 μm, show no time dependence over 6 months, and agree with the broad emission-line flux ratios. This indicates that the mid-IR emission likely comes from scales large enough to be little affected by microlensing and that there is little differential extinction between the images. We measure a revised time delay between these two images of 152.2 (1 σ) days from R- and V-band data covering the years 1997-2006. This time delay indicates that the lens has an approximately flat rotation curve over scales of 1-2Re. We also observed uncorrelated variations of ~0.05 mag yr-1, which we attribute to microlensing of the optical emission from the accretion disk. The optical colors have also changed significantly in the sense that image A is now redder than image B, rather than bluer, as it was in 1993.
Improved separability of dipole sources by tripolar versus conventional disk electrodes: A modeling study using independent component analysis

Tripolar electrodes have been shown to have less mutual information and higher spatial resolution than disc electrodes. In this work, a four-layer anisotropic concentric spherical head computer model was programmed, then four configurations of time-varying dipole signals were used to generate the scalp surface signals that would be obtained with tripolar and disc electrodes. Finally, a fast fixed-point algorithm was used for signal independent component analysis (ICA). The results show that signals from tripolar electrodes generated better ICA separation results than from disc electrodes.
Hydrodynamic Processes in Massive Stars

The hydrodynamic processes operating within stellar interiors are far richer than represented by the best stellar evolution model available. Although it is now widely understood, through astrophysical simulation and relevant terrestrial experiment, that many of the basic assumptions which underlie our treatments of stellar evolution are flawed, we lack a suitable, comprehensive replacement. This is due to a deficiency in our fundamental understanding of the transport and mixing properties of a turbulent, reactive, magnetized plasma; a deficiency in knowledge which stems from the richness and variety of solutions which characterize the inherently non-linear set of governing equations. The exponential increase in availability of computing resources, however, is ushering in a new era of understanding complex hydrodynamic flows; and although this field is still in its formative stages, the sophistication already achieved is leading to a dramatic paradigm shift in how we model astrophysical fluid dynamics. We highlight here some recent results from a series of multi-dimensional stellar interior calculations which are part of a program designed to improve our one-dimensional treatment of massive star evolution and stellar evolution in general.
Specific-to-general learning for temporal events with application to learning event definitions from video

We develop, analyze, and evaluate a novel, supervised, specific-to-general learner for a simple temporal logic and use the resulting algorithm to learn visual event definitions from video sequences. First, we introduce a simple, propositional, temporal, event-description language called AMA that is sufficiently expressive to represent many events yet sufficiently restrictive to support learning. We then give algorithms, along with lower and upper complexity bounds, for the subsumption and generalization problems for AMA formulas. We present a positive-examples-only specific-to-general learning method based on these algorithms. We also present a polynomial-time-computable "syntactic" subsumption test that implies semantic subsumption without being equivalent to it. A generalization algorithm based on syntactic subsumption can be used in place of semantic generalization to improve the asymptotic complexity of the resulting learning algorithm. Finally, we apply this algorithm to the task of learning relational event definitions from video and show that it yields definitions that are competitive with hand-coded ones.
A generalized unstructured artificial neural network architecture: a first study

We present an unstructured neural network based on the mathematics of holographic storage. This work was inspired when we discovered there are similarities between brain waves and the wave propagation and subsequent interference patterns seen in holograms. We then analyzed the mathematics to produce a general mathematical description of the holographic process. From this analysis we are able to show how the holographic process can be used as an associative memory network. Additionally, the process may also be used as a regular feedforward network. The most striking aspect of these networks is that, using the holographic process, the a priori knowledge of the system may be better utilized to tailor the neural network for a particular problem. This aspect, makes this neural network formation process particularly useful for control.
GLOBAL MARINE BIODIVERSITY TRENDS

■ Abstract Marine biodiversity encompasses all levels of complexity of life in the sea, from within species to across ecosystems. At all levels, marine biodiversity has naturally exhibited a general, slow trajectory of increase, punctuated by mass extinctions at the evolutionary scale and by disturbances at the ecological scale. In historical times, a synergy of human threats, including overfishing, global warming, biological
The ultrasonic localization of retrobulbar needles during retrobulbar block.

Purpose: The tips of retrobulbar needles were visualized during retrobulbar block using ultrasound. The purpose of this study is to see how often the needle tip was located 5 mm behind the hind surface of the globe. Methods: Twenty-five patients ranging in age from 22 to 84 years were studied after written informed consent was obtained. An ultrasonic photograph was taken before needle placement, with the needle in the proper position, and after local anesthetic had been injected. Results: In none of the 25 patients studied was the needle tip at the 5-mm mark behind the eye. Placement ranged from 0.2 to 3.3 mm behind the globe. In 14 to 25 placements, the needle shaft was seen actually to indent the globe. The optic nerve was seen to be at least 9 mm from the needle tip in 6 of 25 patients. Conclusion: This study demonstrates that retrobulbar needle tips are closer to the globe than thought previously. A false sense of security may occur when performing retrobulbar blocks using only anatomic landmarks.
Twin-photon confocal microscopy

A recently introduced two-channel confocal microscope with correlated detection promises up to 50% improvement in transverse spatial resolution [Simon, Sergienko, Optics Express 18, 9765 (2010)] via the use of photon correlations. Here we achieve similar results in a different manner, introducing a triple-confocal correlated microscope which exploits the correlations present in optical parametric amplifiers. It is based on tight focusing of pump radiation onto a thin sample positioned in front of a nonlinear crystal, followed by coincidence detection of signal and idler photons, each focused onto a pinhole. This approach offers further resolution enhancement in confocal microscopy.
Cost Economies and Market Power: The Case of the U.S. Meat Packing Industry

Increasing size of establishments and resulting concentration in U.S. industries may stem from various types of cost economies. In particular, scale economies arising from technological factors embodied in plant and equipment may be a driving force for such market structure changes. In this case, typical market power measures like Lerner indices can be misleading: if scale (cost) economies prevail, cost efficiencies rather than market deficiencies may actually underlie the observed patterns. In this study, I provide measures of scale economies and market power for the U.S. meat packing industry, whose increased consolidation and concentration have raised great concern in policy circles. The results suggest that this trend has been motivated by cost economies, but that little excess profitability exists, and on the margin the potential for taking further advantage of such economies has become minimal.
Understanding South Africa's economic puzzles*

South Africa has undergone a remarkable transformation since its democratic transition in 1994, but economic growth and employment generation have been disappointing. Most worryingly, unemployment is currently among the highest in the world. While the proximate cause of high unemployment is that prevailing wages levels are too high, the deeper cause lies elsewhere, and is intimately connected to the inability of the South African to generate much growth momentum in the past decade. High unemployment and low growth are both ultimately the result of the shrinkage of the non-mineral tradable sector since the early-1990s. The weakness in particular of export-oriented manufacturing has deprived South Africa of growth opportunities as well as of job creation at the relatively low end of the skill distribution. Econometric analysis identifies the decline in the relative profitability of manufacturing in the 1990s as the most important contributor to the lack of vitality in that sector.
Preaching to the choir: Internet-mediated advocacy, issue public mobilization, and climate change

Despite the impact that Internet-mediated advocacy organizations have had on American politics over the last decade, we are still learning about how they work. This is even truer for Internet-mediated issue specialists that focus on a single issue, such as climate change. Based on interviews with key staff members of two climate change advocacy campaigns, this article examines how these organizations communicate and mobilize citizens around their issue and the underlying assumptions behind their strategies. Interviews revealed a focus on like-minded issue public mobilization and online-to-offline social movement building strategies. The paper also examines how these organizations can influence policy debates by mobilizing issue publics, shifting debates to more favorable public arenas, and reframing them in ways more favorable to their causes. Implications for the future of climate policy and Internet-mediated advocacy research are discussed.
Approaches to Orthogonally Fused Conducting Polymers For Molecular Electronics

Molecular electronics-based computing instruments possess tremendous technological potential. There is the hope of developing single molecules that could each function as a self-contained electronic device. Thus, one can envision computing systems with molecular-sized electronic elements and operational efficiencies far exceeding that of present systems.3 Recently, Aviram of the IBM Corporation has suggested that molecules which contain a pro-conducting (non-doped or non-oxidized system, hence insulating) polymer which is fixed at a 90° angle via a non-conjugated sigma bonded network to a conducting (doped or oxidized system) should exhibit properties which would make it suitable for interconnection into future molecular electronic devices.4 These devices may be useful for the memory, logic, and amplification computing systems. The molecule 1 (in doped form) is an example of this pro-conducting/sigma/conducting type of molecule.
Multisociety task force for critical care research: key issues and recommendations.

Background Research in critical care extends from the bench to the bedside, involving multiple departments, specialties, and funding organizations. Because of this diversity, it has been difficult for all stakeholders to collectively identify challenges and establish priorities. Objective To define a comprehensive agenda for critical care research using input from a broad range of stakeholders to serve as a blueprint for future initiatives. Methods The Critical Care Societies Collaborative (CCSC), consisting of the leadership of the American Association of Critical-Care Nurses (AACN), the American College of Chest Physicians (ACCP), the American Thoracic Society (ATS), and the Society of Critical Care Medicine (SCCM), joined the US Critical Illness and Injury Trials Group (USCIITG) in forming a task force to define a comprehensive critical care research agenda. This group of 25 identified experts was divided into subgroups to address basic, translational, clinical, implementation, and educational research. The subgroups met via conference calls, and the entire task force met in person for a 2-day session. The result was a detailed discussion of the research priorities that served as the basis for this report. Results The task force identified challenges, specific priority areas, and recommendations for process improvements to support critical care research. Additionally, four overarching themes emerged: 1) the traditional “silo-ed” approach to critical care research is counterproductive and should be modified; 2) an approach that more effectively links areas of research (ie, basic and translational research, or clinical research and implementation) should be embraced; 3) future approaches to human research should account for disease complexity and patient heterogeneity; and 4) an enhanced infrastructure for critical care research is essential for future success. Conclusions This document contains the themes/recommendations developed by a large, multiprofessional cross section of critical care scientists, clinicians, and educators. It provides a unique framework for future research in critical care medicine.
Abstract approach to finite Ramsey theory and a self-dual Ramsey theorem

Abstract We give an abstract approach to finite Ramsey theory and prove a general Ramsey-type theorem. We deduce from it a self-dual Ramsey theorem, which is a new result naturally generalizing both the classical Ramsey theorem and the dual Ramsey theorem of Graham and Rothschild. In fact, we recover the pure finite Ramsey theory from our general Ramsey-type result in the sense that the classical Ramsey theorem, the Hales–Jewett theorem (with Shelahʼs bounds), the Graham–Rothschild theorem, the versions of these results for partial rigid surjections due to Voigt, and the new self-dual Ramsey theorem are all obtained as iterative applications of the general result.