cssi/SciSciGPT-SciSciNet huggingface dataset:
Stability And Accuracy Of The Sweep Rate Measurements For LLNL Optical Streak Cameras

ABSTRACT Precise pulse shaping is vital for present and future high-power lasers that will attempt to achieve low-entropy laser- fusion implosions. Multichannel, streak-camera-based systems are used to make such measurements. Such systems must be accurately calibrated in order to correct for time-base and flat-field variations. We use an on-line calibration system in order to measure the sweep rate, and in our recent work we have evaluated the accuracy of this measurement technique. By analyzing a large number of calibrations, and the effect of noise on our measurement technique, we have concluded that the sweep rate for our streak camera systems is reproducible to at least ±1.2% and that our measurement technique contributes an additional ±0.5% uncertainty in the measurement1. INTRODUCTIONLaser fusion research is moving into an era when experiments using precise pulse shaping are important. Such pulse shaping is necessary in order to accelerate the shell of a fuel capsule to high velocity without generating shock waves so strong that the entropy of the fuel is unacceptably increased. In order to shape the laser pulse precisely, one must be able to measure it precisely. And in order to make such measurements throughout a large laser facility such as Nova, multichannel measurements using numerous streak cameras are important. There are more than 8 LLNL optical streak cameras5'6 in use throughout the Nova laser facility4 to measure laser pulse shapes. These cameras must be reliably and routinely able to make precise pulse-shape measurements several times a day or more.In the pursuit of making reliable, accurate pulse-shape measurements we have developed the ability to calibrate streak camera systems in order to correct the data for time-base nonlinearities and for flat-field variations in sensitivity1 '2 . In particular, we have developed a 3 GHz comb generator3 to provide a train of light pulses that can be used to calibrate the sweep. In our recent work8 , we have analyzed data from this system to determine the accuracy of the sweep rate measurements using the comb, and to evaluate the stability of the streak camera sweep rate. In the following, we describe the setup of the streak cameras and we summarize our analysis of the comb data.
The Public Utility Pyramids

AbstractIn the 1920s and 1930s, many public utilities in the United States were controlled by holding companies organized in pyramid form. This structure can add value to subsidiaries but can also facilitate extraction of wealth from the subsidiaries’ public shareholders. I examine the effects of the Public Utility Holding Company Act of 1935 (PUHCA), which outlawed pyramid structures. The value of both top holding companies and their subsidiaries fall (rise) around the time of key legislative events favorable (unfavorable) to the enactment of PUHCA, supporting the hypothesis that public shareholders benefited from the presence of a controlling shareholder.
Lagrangian fibrations on Hilbert schemes of points on K3 surfaces

Let $\mathrm{Hilb}^gS$ be the Hilbert scheme of $g$ points on a K3 surface $S$. Suppose that $\mathrm{Pic}S\cong\Z C$ where $C$ is a smooth curve with $C^2=2(g-1)n^2$. We prove that $\mathrm{Hilb}^gS$ is a Lagrangian fibration.
Domain wall junctions in supersymmetric field theories in D = 4

We study the possible BPS domain wall junction configurations for general polynomial superpotentials of = 1 supersymmetric Wess-Zumino models in D = 4. We scan the parameter space of the superpotential and find different possible BPS states for different values of the deformation parameters and present our results graphically. In this way we obtain a complete picture of the possible BPS domain wall junctions for the models we consider. We comment on the domain walls in F/M/IIA theories obtained from the Calabi-Yau fourfolds with isolated singularities and a background flux.
System instability of evaporative micro-channels

Abstract In parallel evaporative micro-channels, system instability may occur in terms of cyclical fluctuations at a long period. This is due to the co-existence of the liquid phase flow at high mass flux and the two-phase flow at a lower mass flux among different parallel channels under the same total pressure drop. For a system at constant flow rate pumping, with a pressure regulating tank and a constant heating pre-heater, alternations between these two states of boiling and non-boiling could happen with a period of minutes. This cyclical system instability has been modeled, where the liquid phase flow occurs at conditions of high inlet subcooling and low surface heat flux that the boiling inception is hard to initiate. The system instability criteria are established in terms of a system binary states parameter, S, and a non-dimensional surface heat flux. This model has been validated experimentally.
Model-based segmentation of nuclei

Abstract A new approach for the segmentation of nuclei observed with an epi-fluorescence microscope is presented. The proposed technique is model based and uses local feature activities in the form of step-edge segments, roof-edge segments, and concave corners to construct a set of initial hypotheses. These local feature activities are extracted using either local or global operators and corresponding hypotheses are expressed as hyperquadrics. A neighborhood function is defined over these features to initiate the grouping process. The search space is expressed as an assignment matrix with an appropriate cost function to ensure local and neighborhood consistency. Each possible configuration of nucleus defines a path and the path with least overall error is selected for final segmentation. The system is interactive to allow rapid localization of large numbers of nuclei. The operator then eliminates a small number of false alarms and errors in the segmentation process.
The use of a portable analog computer for process identification, calculation and control

In the design and development of controlled processes there are two areas of intense activity---the theoretical simulation of the total plant and empirical simulations involving the collection of reliable experimental data to assist in the construction of a special purpose model. The simulation of a newly proposed process, even from the best available theoretical basis, is usually only approximate. It requires use of large and expensive computer installations, either analog and/or digital, so that by direct programming of the design criteria, the optimum plant operating conditions may be determined. However, even if such a model were extremely reliable (pilot plant), the scaleup problems are quite complex. In some cases, it might be well-nigh impossible to maintain the exact relationships between certain intrinsic parameters, surface tension, heat transfer, etc.---and, of course, few theoretical models can anticipate all the significant process characteristics. As a result, many full scale plants are in need of partial redesign. The authors feel that techniques relying on plant data are indispensable for accomplishing this end.
Multiplicative updates in coordination games and the theory of evolution

In this paper we point out a new and unexpected connection between three fields: Evolution Theory, Game Theory, and Algorithms.In particular, we study the standard equations of population genetics for Evolution, in the presence of recombination (sex), focusing on the important special case of weak selection [1,2] in which all fitness values are assumed to be close to one another. Weak selection is the mathematical regime capturing the widely accepted Neutral Theory proposed by Kimura in the 1970s [3], hypothesizing that evolution proceeds for the most part not by substantial increases in fitness but by essentially random drift. We show that in this regime evolution through natural selection and sex is tantamount to a game played through the multiplicative weight updates game dynamics [4]. The players of the game are the genes (genetic loci), the strategies available to each player are the alleles of the gene, and the probabilities whereby a player plays a strategy is the strategy's frequency in the population. The utility to each player/gene of each strategy profile is the fitness of the corresponding genotype (organism). That is, the game is a coordination game between genes, in which the players' interests are perfectly aligned. Importantly, the utility maximized in this game, as well as the amount by which each allele is boosted, is precisely the allele's mixability, or average fitness, a quantity recently proposed in [5] as a novel concept that is crucial in understanding natural selection under sex, thus providing a rigorous demonstration of that insight.We also establish a result regarding the maintenance of genetic diversity (multiplicity of alleles per gene). We prove that the equilibria in two-person coordination games are likely to have large supports, and thus genetic diversity need not suffer much at equilibrium. Establishing large supports involves answering through a novel technique the following question: what is the probability that for a random square matrix $A$ (with entries drawn independently from smooth distributions that are symmetric around zero) both systems Ax=1 and ATy=1 have positive solutions? The proof is through a simple potential function argument. Both the question and the technique may be of broader interest.It has often seemed astonishing --- even to experienced students of Evolution, Darwin included --- that the crude mechanism of natural selection is responsible for producing the dazzling variety of Life around us. The present mathematical connection of Evolution with the multiplicative weight updates algorithm --- a technique that has surprised our field time and again with its fantastic effectiveness and versatility --- may carry some explanatory force in this regard.
Dynamical feedbacks and the persistence of the NAO

The persistence of the North Atlantic Oscillation (NAO) is studied using observations of the threedimensional vorticity budget in the Atlantic sector. Analysis of the relative vorticity tendency equation shows that convergence of eddy vorticity flux in the upper troposphere counteracts the effect of anomalous largescale divergence at the upper level. At low levels, the convergence associated with this large-scale vertical circulation cell maintains the relative vorticity anomaly against frictional drag. The eddy vorticity flux convergence thus acts to sustain the vorticity anomaly associated with the NAO against drag and increases the persistence of the NAO vorticity anomaly. The adiabatic cooling associated with the rising motion in the vorticity maximum sustains the thermal structure of the NAO anomaly, enhancing the baroclinicity, and thus eddy generation. This constitutes a positive eddy feedback that helps maintain the NAO. The positive eddy feedback occurs only in the midlatitude region and is strongest during the negative phase of the NAO when the Atlantic jet is displaced toward the equator, with a high pressure anomaly to the north and a low pressure anomaly to the south. The stronger feedback demonstrated during the negative phase is consistent with the greater persistence observed for this phase of the NAO. The positive feedback appears to be associated with anomalous northward eddy propagation away from the jet.
A dielectric flow solution with maximal supersymmetry

We obtain a solution to eleven-dimensional supergravity that consists of M2-branes embedded in a dielectric distribution of M5-branes. Contrary to normal expectations, this solution has maximal supersymmetry for a brane solution (i.e. sixteen supercharges). While the solution is constructed using gauged supergravity in four dimensions, the complete eleven-dimensional solution is given. In particular, we obtain the Killing spinors explicitly, and we find that they are characterised by a duality rotation of the standard Dirichlet projection matrix for M2-branes.
Influence of potential function asymmetries on the performance of nonlinear energy harvesters under white noise

Abstract To improve the broadband transduction capabilities of vibratory energy harvesters (VEHs) under random and non-stationary excitations, many researchers have resorted to purposefully introducing nonlinearities into the restoring force of the harvester. While performing this task, it is often very challenging to maintain a perfectly symmetric restoring force which yields a VEH with an asymmetric potential energy function. This paper investigates the influence of potential function asymmetries on the performance of nonlinear VEHs under white noise inputs. To that end, a quadratic nonlinearity is introduced into the restoring force and its influence on the mean output power of the harvester for mono- and bi-stable quartic potentials is investigated. It is shown that, for VEHs with a mono-stable quartic potential function, the mean output power increases with the degree of potential function asymmetry. On the other hand, for energy harvesters with a bi-stable quartic potential function, asymmetries in the restoring force appear to worsen performance especially for low to moderate noise intensities. When the noise intensity becomes sufficiently large, the influence of the potential function׳s asymmetry on the mean power diminishes. Results also reveal that a VEH with a symmetric bi-stable quartic potential function produces higher mean power levels than the one with the most asymmetric mono-stable potential. As such, it is concluded that a VEH with a symmetric bi-stable potential is most desirable to improve performance under white noise.
Sales margin and margin capitalization rates: linking marketing activities to shareholder value

Using customer level data, prior marketing research has developed a micro or bottom up approach to link marketing activities with shareholder value. This study develops a macro or top down approach using longitudinal firm level data from publicly available financial statements. Test results show that the earnings component supported by sales has higher pricing multiples than other components of earnings in firm specific time-series data. We also test hypotheses of five marketing-related drivers of sales capitalization rate (the rate at which sales increases are converted into increased shareholder value). From the research effort, we develop three managerially useful tools. First, we suggest enterprises develop alpha or sales margin strategies and beta or margin capitalization strategies, and we show that one can map these strategies into a planning matrix. Second, using financial statements of publicly traded firms, we develop an alternative method of estimating customer equity. Third, we show how a company may use our macro approach and compare its performance with its industry competitors to develop insights into competitive dynamics.
Separate and Unequal in the Labor Market: Human Capital and the Jim Crow Wage Gap

Competing explanations for the long-standing gap between black and white earnings attribute different weight to wage discrimination and human capital differences. Using new data on local school quality, we find that human capital played a predominant role in determining 1940 wage and occupational status gaps in the South despite entrenched racial discrimination in civic life and the lack of federal employment protections. The resulting wage gap coincides with the higher end of the range of estimates from the post–Civil Rights era. We estimate that truly “separate but equal” schools would have reduced wage inequality by 29%–48%.
Those who were born poor: A qualitative study of Philippine poverty.

This qualitative study investigated the psychological experience of poverty among 2 groups of Filipinos who were interviewed about the effects of being raised poor, 12 who became rich, and 13 who remained poor. Using constructivist and critical theories as research paradigms and grounded theory as methodology, the results of the study illustrated perceived causes, coping mechanisms, and cultural factors. Surprisingly, both groups were very similar in their experiences of not having basic needs met, of negative emotions, and of generally attributing their poverty to familial circumstances. The ways of coping with poverty, such as receiving and giving assistance and imploring God for help, and the cultural features of perseverance (pagpupunyagi) and reliance on others (pakikipagkapwa) were similarly influential in both groups. Because the main difference between both groups is the occurrence of chance events that provided access to education and opportunities to emigrate for those who have become rich, the oppressive structures of a society that perpetuate poverty are discussed. In developing countries such as the Philippines, the psychological experience of poverty is characterized by the impossibility of upward mobility.
Optimal control of systems with hard control bounds

The numerical solution of the optimal control and trajectory of systems with hard control bounds is considered. A new algorithm, which extends the gradient method [1] to systems with hard control bounds is presented. The algorithm is based on the use of an adjustable control-variation weight (ACW) matrix to enforce the bounds. The application of the algorithm to the minimum-time control of a two-link robot arm is presented as an example.
Evolutionary Signatures in the Formation of Low-Mass Protostars

We present an evolutionary picture of a forming star. We assume a singular isothermal sphere as the initial state of the core that undergoes collapse, as described by Shu. We include the evolution of a first hydrostatic core at early times and allow a disk to grow, as predicted by Adams & Shu. We use a one-dimensional radiative transfer code to calculate the spectral energy distribution for the evolving protostar from the beginning of collapse to the point when all envelope material has accreted onto the star + disk system. Then, we calculate various observational signatures (Tbol, Lbol/Lsmm, and infrared colors) as a function of time. As defined by the bolometric temperature criterion, the Class 0 stage should be very short, while the Class I stage persists for much of the protostar's early life. We present physical distinctions among the classes of forming stars and calculate the observational signatures for these classes. Finally, we present models of infrared color-magnitude diagrams, as observed by the Spitzer Space Telescope, that should be strong discriminators in determining the stage of evolution for a protostar.
ALMA capabilities for observations of spectral line emission

The Atacama Large Millimeter/submillimeter Array (ALMA) (The Enhanced Atacama Large Millimeter/submillimeter Array (known as ALMA) is an international astronomy facility. ALMA is a partnership between North America, Europe, and Japan/Taiwan, in cooperation with the Republic of Chile, and is funded in Europe by the European Southern Observatory (ESO) and Spain, in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC), and in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan. ALMA construction and operations are led on behalf of Japan/Taiwan by the National Astronomical Observatory of Japan (NAOJ), on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), and on behalf of Europe by ESO) combines large collecting area and location on a high dry site to provide it with unparalleled potential for sensitive millimeter/submillimeter spectral line observations. Its wide frequency coverage, superb receivers and flexible spectrometer will ensure that its potential is met. Since the 1999 meeting on ALMA Science (Wootten, ASP Conf. Ser. 235, 2001), the ALMA team has substantially enhanced its capability for line observations. ALMA’s sensitivity increased when Japan joined the project, bringing the 16 antennas of the Atacama Compcat Array (ACA), equivalent to eight additional 12 m telescopes. The first four receiver cartridges for the baseline ALMA (Japan’s entry has brought two additional bands to ALMA’s receiver retinue) have been accepted, with performance above the already-challenging specifications. ALMA’s flexibility has increased with the enhancement of the baseline correlator with additional channels and flexibility, and with the addition of a separate correlator for the ACA. As an example of the increased flexibility, ALMA is now capable of multi-spectral-region and multi-resolution modes. With the former, one might observe e.g. four separate transitions anywhere within a 2 GHz band with a high resolution bandwidth. With the latter, one might simultaneously observe with low spectral resolution over a wide bandwidth and with high spectral resolution over a narrow bandwidth; this mode could be useful for observations of pressure-broadened lines with narrow cores, for example. Several science examples illustrate ALMA’s potential for transforming millimeter and submillimeter astronomy.
Approximating Nearest Neighbor Distances

Several researchers proposed using non-Euclidean metrics on point sets in Euclidean space for clustering noisy data. Almost always, a distance function is desired that recognizes the closeness of the points in the same cluster, even if the Euclidean cluster diameter is large. Therefore, it is preferred to assign smaller costs to the paths that stay close to the input points.
Transmission Strategies in Multiple-Access Fading Channels With Statistical QoS Constraints

Effective capacity, which provides the maximum constant arrival rate that a given service process can support while satisfying statistical queueing constraints, is analyzed in a multiuser scenario. In particular, the effective capacity region of fading multiple-access channels in the presence of quality of service (QoS) constraints is studied. Perfect channel side information is assumed to be available at both the transmitters and the receiver. It is initially assumed that the transmitters send the information at a fixed power level and, hence, do not employ power control policies. Under this assumption, the performance achieved by superposition coding with successive decoding techniques is investigated. It is shown that varying the decoding order with respect to the channel states can significantly increase the achievable throughput region. In the two-user case, the optimal decoding strategy is determined for the scenario in which the users have the same QoS constraints. The performance of orthogonal transmission strategies is also analyzed. It is shown that for certain QoS constraints, time-division multiple access can achieve better performance than superposition coding if fixed successive decoding order is used at the receiver side. In the subsequent analysis, power control policies are incorporated into the transmission strategies. The optimal power allocation policies for any fixed decoding order over all channel states are identified. For a given variable decoding-order strategy, the conditions that the optimal power control policies must satisfy are determined, and an algorithm that can be used to compute these optimal policies is provided.
On Collisionless Electron-Ion Temperature Equilibration in the Fast Solar Wind

We explore a mechanism, entirely new to the fast solar wind, of electron heating by lower hybrid waves to explain the shift to higher charge states observed in various elements in the fast wind at 1 AU relative to the original coronal hole plasma. This process is a variation on that previously discussed for two-temperature accretion flows by Begelman & Chiueh. Lower hybrid waves are generated by gyrating minor ions (mainly α-particles) and become significant once strong ion cyclotron heating sets in beyond 1.5 R☉. In this way the model avoids conflict with SUMER electron temperature diagnostic measurements between 1 and 1.5 R☉. The principal requirement for such a process to work is the existence of density gradients in the fast solar wind, with scale length of similar order to the proton inertial length. Similar size structures have previously been inferred by other authors from radio scintillation observations and considerations of ion cyclotron wave generation by global resonant MHD waves.
The Origin of Chondrules and Chondrites

1. Historical introduction 2. Potential meteorite parent bodies 3. Chondrites and their main properties 4. Chondrules and their main properties 5. Theories for the origin of chondrules 6. Discussion of theories for the origin of chondrules 7. Making the chondrites: chondrule sorting and metal-silicate fractionation 8. So how far have we come and where do we go next?
A Negative Mass Theorem for Surfaces of Positive Genus

Let M be a closed surface. For a metric g on M, denote the Laplace-Beltrami operator by Δ = Δg. We define trace \({\Delta^{-1} = \int_M m(p)dA}\) , where dA is the area element for g and m(p) is the Robin constant at the point \({p \in M}\) , that is the value of the Green function G(p, q) at q = p after the logarithmic singularity has been subtracted off. Since trace Δ−1 can also be obtained by regularization of the spectral zeta function, it is a spectral invariant. Heuristically it represents the sum of squares of the wavelengths of the surface. We define the Δ-mass of (M, g) to equal \({({\rm trace} \Delta_g^{-1} - {\rm trace} \Delta_{S^{2},A}^{-1})/A}\) , where \({\Delta_{S^2,A}}\) is the Laplacian on the round sphere of area A. This is an analog for closed surfaces of the ADM mass from general relativity. We show that if M has positive genus, the minimum of the Δ-mass on each conformal class is negative and attained by a smooth metric. For this minimizing metric, there is a sharp logarithmic Hardy-Littlewood-Sobolev inequality and a Moser-Trudinger-Onofri type inequality.
Optimal computation of symmetric Boolean functions in tree networks

In this paper, we address the scenario where nodes with sensor data are connected in a tree network, and every node wants to compute a given symmetric Boolean function of the sensor data. We first consider the problem of computing a function of two nodes with integer measurements. We allow for block computation to enhance data fusion efficiency, and determine the minimum worst-case total number of bits to be exchanged to perform the desired computation. We establish lower bounds using fooling sets, and provide a novel scheme which attains the lower bounds, using information theoretic tools. For a class of functions called sum-threshold functions, this scheme is shown to be optimal.
Effect of solar radiation disturbance on a flexible beam in orbit

The uncontrolled dynamics of an orbiting flexible beam in the presence of solar radiation pressure forces is considered. The effect of solar radiation forces and moments on the rigid and flexible modes of a free-free flexible beam is evaluated. It is found that moments result only from the flexible symmetric modal deformations. For small pitch amplitudes, and at near geosynchronous altitudes the solar radiation moments due to the deformations of the beam are seen to be greater than those due to the gravity-gradient. Within the linear range, simulated steady state dynamic responses show that the induced pitch amplitudes can be more significant than the induced amplitudes of the modal shape functions.
Overground Physical Therapy Gait Training for Chronic Stroke Patients With Mobility Deficits

Background and Purpose— Overground gait training can be defined as a physical therapists’ observation and cueing of the patient’s walking pattern along with related exercises, but does not include high-technology aids such as functional electric stimulation or body weight support. This systematic review investigated the effects of overground physical therapy gait training on walking ability for chronic stroke patients with mobility deficits. Methods— A comprehensive literature search was performed as per the Cochrane group guidelines. Only randomized controlled trials that compared overground physical therapy gait training to a placebo intervention or no treatment for chronic stroke patients with mobility deficits were included. Results— Nine studies involving 499 participants matched the inclusion criteria and had moderate methodological quality. Results were mixed with no significant effect on the primary variable, gait function. Small effects for several performance variables were found: gait speed inc...
Concurrent Optimization of Mesh Refinement and Design Parameters in Multidisciplinary Design

accuracy in terms of discretization error. Further discussed are the challenges that a design-optimization setting poses to the estimation of discretization error and how the ‘optimum’ mesh-refinement assessment is, in fact, nested within the design-optimization problem. The paper puts forth two significant contributions for multidisciplinary design-optimization formulations: 1) investigation of the impact of the so-called design inputs to discretization error in multidisciplinary design optimization, and 2) development of a concurrent optimization framework for simultaneous mesh refinement and design parameter optimization for multidisciplinary systems. The proposed method is illustrated using a simplified aircraft wing-design problem. I. Introduction I
Interaction of neutrinos with a cosmological k-essence scalar

In this paper we study a novel means of coupling neutrinos to a Lorentz violating background k-essence field. We first look into the effect that k-essence has on the neutrino dispersion relation and derive a general formula for the neutrino velocity in the presence of a k-essence background. The influence of k-essence coupling on neutrino oscillations is then considered. It is found that if k-essence couples non-diagonally to the neutrino flavor eigenstates, then this leads to an oscillation length that goes like λ ∼ E −1, where E is the neutrino energy. This should be contrasted with the λ ∼ E dependence seen in mass-induced neutrino oscillations. While such a scenario is not favored experimentally, it places constraints on the possible interaction that a k-essence background can have with neutrinos by requiring it to be flavor diagonal. All nontrivial physical effects discussed here require the sound speed of k-essence fluctuations to be different from the speed of light, and hence are primarily a consequence of Lorentz violation.
Computing the aspect graph for line drawings of polyhedral objects

An algorithm for computing the aspect graph for polyhedral objects is described. The aspects graph is a representation of three-dimensional objects by a set of two-dimensional views. The set of viewpoints on the Gaussian sphere is partitioned into regions such that in each region the qualitative structure of the line drawing remains the same. At the boundaries between adjacent regions are the accidental viewpoints where the structure for the line drawing changes. It is shown that for polyhedral objects there are two fundamental visual events: (1) the projections of an edge and a vertex coincide; and (2) the projections of three nonadjacent edges intersect at a point. The geometry of the object is reflected in the locus of the accidental viewpoints. The algorithm computes the partition together with a representative view for each region of the partition. >
The matricellular protein CCN1 controls retinal angiogenesis by targeting VEGF, Src homology 2 domain phosphatase-1 and Notch signaling

Physiological angiogenesis depends on the highly coordinated actions of multiple angiogenic regulators. CCN1 is a secreted cysteine-rich and integrin-binding matricellular protein required for proper cardiovascular development. However, our understanding of the cellular origins and activities of this molecule is incomplete. Here, we show that CCN1 is predominantly expressed in angiogenic endothelial cells (ECs) at the leading front of actively growing vessels in the mouse retina. Endothelial deletion of CCN1 in mice using a Cre-Lox system is associated with EC hyperplasia, loss of pericyte coverage and formation of dense retinal vascular networks lacking the normal hierarchical arrangement of arterioles, capillaries and venules. CCN1 is a product of an immediate-early gene that is transcriptionally induced in ECs in response to stimulation by vascular endothelial growth factor (VEGF). We found that CCN1 activity is integrated with VEGF receptor 2 (VEGF-R2) activation and downstream signaling pathways required for tubular network formation. CCN1-integrin binding increased the expression of and association between Src homology 2 domain-containing protein tyrosine phosphatase-1 (SHP-1) and VEGF-R2, which leads to rapid dephosphorylation of VEGF-R2 tyrosine, thus preventing EC hyperproliferation. Predictably, CCN1 further brings receptors/signaling molecules into proximity that are otherwise spatially separated. Furthermore, CCN1 induces integrin-dependent Notch activation in cultured ECs, and its targeted gene inactivation in vivo alters Notch-dependent vascular specification and remodeling, suggesting that functional levels of Notch signaling requires CCN1 activity. These data highlight novel functions of CCN1 as a naturally optimized molecule, fine-controlling key processes in physiological angiogenesis and safeguarding against aberrant angiogenic responses.
Berry-phase theory of proper piezoelectric response

Abstract Recent theoretical advances have established that the electric polarization in an insulating crystal can be viewed as a multivalued quantity that is determined by certain Berry phases associated with the occupied Bloch bands. The application of this approach to the computation of piezoelectric coefficients is not entirely straightforward, since a naive determination of the (“improper”) piezoelectric coefficients from finite differences of the polarization at nearby strain states leads to a dependence upon the choice of “branch” of the polarization. The purpose of the present paper is to clarify that if one calculates instead the “proper” piezoelectric response, the branch dependence is eliminated. From this analysis, a simplified recipe for the direct finite-difference computation of the proper piezoelectric coefficients emerges naturally.
Age and Neuroinflammation: A Lifetime of Psychoneuroimmune Consequences

Aging can impair functional interaction that occurs between the brain and the immune system. Recent findings indicate that microglia and astrocytes, innate immune cells of the brain, become more reactive during normal aging. This age-associated increase in innate immune reactivity sets the stage for an exaggerated inflammatory cytokine response in the brain after activation of the peripheral innate immune system. This elevated neuroinflammatory response may lead to more severe long-lasting behavioral and cognitive deficits. This article discusses new evidence that aging creates a brain environment that is permissive to the occurrence of mental health complications following innate immune activation.
Three-wavelength interconversion laser

A new mode of operation has been discovered that permits a laser to operate simultaneously at three wavelengths; two have gain and the third occurs at the sum frequency. A Nd:YAG laser operated in this way generates output at 1319, 1064, and 589 nm. This laser has been mode locked and its dynamics studied.
The proposed patients' bill of rights: the case of the missing equal protection clause.

Following the footsteps of most other states, Massachusetts opened its Office of Patient Protection in January 2001. Established under what the media hailed as a “landmark” patients’ bill of rights, the Massachusetts legislature created a state agency empowered to review medical decisions made by health maintenance organizations (HMOs) that are challenged by patients. However, after opening its doors, the agency now faces an immediate and major problem—the lack of any patient complaints. On January 27, 2001, the Boston Globe reported the agency’s activity as follows: “[I]n their first three weeks, the medical crusaders in this little office have been more like those proverbial Maytag repairmen—twiddling their thumbs in boredom. The office, established under a landmark patients’ bill of rights as a referee between HMOs and clients, has yet to hear a single beef.” While the problem may be due to a lack of knowledge about the availability of the appeals process, the immediate result of this Massachusetts reform mirrors the longer-term experience of other states. Health policy researchers at Georgetown University analyzed the limited reliance of patients on the right to appeal HMO decisions and found that patients rarely exercise their newly found due process rights to appeal treatment denials. For example, in the first five years of Florida’s external review process (from 1993 to 1998), only 403 cases arose in a population of 4.4 million state residents enrolled in managed care plans. Despite the relatively small impact of this health care reform effort by various states, it appears that Congress will soon pass similar “landmark” federal legislation. In the past year, the presidential candidates and the U.S. Congress
Accelerating large-scale data exploration through data diffusion

Data-intensive applications often require exploratory analysis of large datasets. If analysis is performed on distributed resources, data locality can be crucial to high throughput and performance. We propose a "data diffusion" approach that acquires compute and storage resources dynamically, replicates data in response to demand, and schedules computations close to data. As demand increases, more resources are acquired, thus allowing faster response to subsequent requests that refer to the same data; when demand drops, resources are released. This approach can provide the benefits of dedicated hardware without the associated high costs, depending on workload and resource characteristics. The approach is reminiscent of cooperative caching, web-caching, and peer-to-peer storage systems, but addresses different application demands. Other data-aware scheduling approaches assume dedicated resources, which can be expensive and/or inefficient if load varies significantly. To explore the feasibility of the data diffusion approach, we have extended the Falkon resource provisioning and task scheduling system to support data caching and data-aware scheduling. Performance results from both micro-benchmarks and a large scale astronomy application demonstrate that our approach improves performance relative to alternative approaches, as well as provides improved scalability as aggregated I/O bandwidth scales linearly with the number of data cache nodes.
Antitumor compounds from tunicates.

Of the six marine-derived compounds that have reached clinical trials as antitumor agents three-didemnin B, Aplidine, and ecteinascidin 743-are derived from tunicates. Di-demnin B (DB), a cyclic depsipeptide from the compound tunicate Trididemnum solidum, was the first marine-derived compound to enter Phases I and II clinical trials. The Phase II studies, sponsored by the U. S. National Cancer Institute, indicated complete or partial remissions with non-Hodgkins lymphoma, but cardiotoxicity caused didemnin B to be dropped from further study. The closely related dehydrodidemnin B (DDB, Aplidine) was isolated in 1988 from a second colonial tunicate, Aplidium albicans, and spectroscopic studies assigned a structural formula in which a pyruvyl group in DDB replaced the lactyl group in DB and syntheses of DDB have been achieved. Aplidine is more active than DB and lacks DB's cardiotoxicity. It was introduced by PharmaMar into Phase I clinical trials in January 1999. The second family of tunicate-derived antitumor agents are the ecteinascidins (ETs), from the mangrove tunicate Ecteinascidia turbinata. The antitumor extracts of E. turbinata were first described in 1969, but the small amount of ETs in E. turbinata prevented their isolation for over a decade. The structures of ETs have been assigned mainly by spectroscopy. Phase II clinical trials with ET 743 are underway. Future supplies of ET's should be available from aquaculture or synthesis.
Gated Decap: Gate Leakage Control of On-Chip Decoupling Capacitors in Scaled Technologies

To minimize the leakage power dissipation of present-day on-chip Decaps, we propose a gated decoupling capacitor (GDecap) technique that deactivates a Decap when it is not needed. The application of the proposed GDecap technique on an eight-way clock-gated clustered pipeline showed that on average, 41.7% Decap leakage power was reduced, with negligible (~ 0.037%) worst-case performance degradation, at the 70-nm technology node. GDecap design incurred an area overhead of around 5.36% when compared with a conventional Decap design.
Thermostructural concepts for hypervelocity vehicles

In the design of hypervelocity veh~cles (HVV). a key driving parameter is the structural mass fraction of the system. The mass fraction greatly influences the performance and payload capabilities of the vehicle. For example. a reduction of one pound of structural weight would effectively translate into an additional pound of payload, or alternatively, approximately ten fewer pounds of propellant. Through the optimization of thermostructural concepts. a significant increase in overall mission perfbrmance can be reallred. Such an optimiration requires not only good familiarity with the available material optlons and therrnostructural concepts. but also a thorough knowledge of the thermal. inertial, aerodynamic, and control loads on the vehicle as a consequence of hqpervelocity flight conditions. This optimiration process the establishment o l aeroheating and other critical loads, the consideration of material alternatives, and the formulation of thermostructural concep t wa the primary l'i~cus ol' t h ~ \ study. A suborbital vehicle (Figure I ) and the aswciated trajectory (Figure 2 ) a i described in Rckrence I were chosen as stud) baselines. These selections wcrc Idlowed b> a series of interrclated design and anal] tical tazks. during which a number of thcri~~ostructural trade \tudie\ \\el-c conducted. The primary results ol'the stud! include detailed w i g h t estlmates h r the candidate thernio~tructural concepts and the selecSUB-ORBITER SYNERGETIC PLANE CHANGE
Synthesis, Structure, and High Temperature Thermoelectric Properties of Yb11Sb9.3Ge0.5

Zintl phase compounds with large unit cells and complex anionic structures such as Yb11Sb10 hold potential for being good thermoelectric materials. Single crystals of Ge-doped Yb11Sb10 were synthesized using a molten Sn-flux technique. Single crystal X-ray diffraction data were obtained and resulted in a composition of Yb11Sb9.3Ge0.5 which was verified by microprobe. Yb11Sb9.3Ge0.5 is isostructural to Ho11Ge10, crystallizing in a body-centered, tetragonal unit cell, space group I4/mmm, with Z = 4. The unit cell parameters of Yb11Sb9.3Ge0.5 are a = 11.8813(4), c = 17.1276(13) A with a volume of 2417.8(2) A3. These parameters correlate well with the structural refinement of previously published Yb11Sb10. The structure consists of 16 isolated Sb3− anions, 8 dumbbells, 2 square planar rings and 44 Yb2+ cations. The Ge, doped in at 28 % occupancy, was found to be site specific, residing on the 2 square planar rings. Single crystal X-ray diffraction is most consistent with the site that makes up the square ring being less than fully occupied. The doped compound is additionally characterized by X-ray powder diffraction, differential scanning calorimetry and thermogravimetry. High temperature (300–1200 K) thermoelectric properties show that the doped compound has extremely low thermal conductivity (10–30 mW/cmK), lower than that of Yb11Sb10. Temperature dependent resistivity is consistent with a heavily doped semiconductor. Yb11Sb9.3Ge0.5 shows p-type behavior increasing from ∼22 μV/K at room temperature to ∼31 μV/K at 1140 K. The low value and the temperature dependence of the Seebeck coefficient suggest that bipolar conduction produces a compensated Seebeck coefficient and consequently a low zT.
Computing wiener-type indices for virtual combinatorial libraries generated from heteroatom-containing building blocks.

The expensive and time-consuming process of drug lead discovery is significantly accelerated by efficiently screening molecular libraries with a high structural diversity and selecting subsets of m...
ON SUPERFLUIDITY AND SUPPRESSED LIGHT SCATTERING IN BECs

We show that the suppression of light scattering off a Bose Einstein Condensate is equivalent to the Landau argument for superfluidity and thus is a consequence of the Principle of Superfluidity. The superfluid ground state of a BEC contains nonseparable, nontrivial correlations between the bosons that make up the system, i.e., it is entangled. The correlations in the ground state entangle the bosons into a coherent state for the lowest energy state. The entanglement is so extreme that the bosons that make up the system cannot be excited at long wavenumbers. Their existence at low energies is impossible. Only quantum sound can be excited, i.e. the excitations are Bogolyubov quasiparticles which do not resemble free bosons whatsoever at low energies. This means that the system is superfluid by the Landau argument and the superfluidity is ultimately the reason for suppressed scattering at low wavelengths.
A neural network based expert system model

The architecture of an expert system model using artificial neural networks is proposed. The proposed model effectively supports the necessary components of an expert system such as user interface facility knowledge base, inference engine, and explanation system. The expert system model (ESM) consists of several orders of simple neural networks, each realizing a simple task. These simple neural networks are organized vertically, thereby achieving a second level of parallelism. A novel way to handle both forward and backward chaining reasoning mechanisms is presented. A secondary network model monitors the reasoning patterns of the primary model. >
Are there global norms and universal standards of electoral integrity and malpractice? Comparing public and expert perceptions

When international observers criticize the quality of elections, do these expert evaluations reflect 'Western/American' values? Or are there universal global norms of electoral integrity and malpractice which are shared by ordinary people living in diverse cultures? To consider these issues, Part I of this paper unpacks the core concept of electoral integrity. Part II introduces a new battery of nine items carried for the first time in the 6 th wave of the World Values Survey (WVS) 2010-12. This battery is designed to gauge perceptions of common types of electoral integrity and malpractice. Part III describes the results of the survey. Part IV then compares mass perceptions in each country against five summary indices based on expert evaluations. The conclusion summarizes the main findings and considers their implications.
The Claisen condensation in biology

The mechanism for carbon-carbon bond formation used in the biosynthesis of natural products such as fatty acids and polyketides is a decarboxylating Claisen condensation. The enzymes that catalyze this reaction in various bacterial systems, collectively referred to as condensing enzymes, have been intensively studied in the past several decades, and members of the family have been crystallized. The condensing enzymes share a common 3-dimensional fold, first described for the biosynthetic thiolase I that catalyzes a non-decarboxylating Claisen condensation, although they share little similarity at the amino acid level. Their active sites, however, possess significant similarities. The initiation condensing enzymes use CoA primers and possess a catalytic triad of Cys, His, Asn; and the elongating condensing enzymes that exclusively use ACP thioesters have a triad of Cys, His, His. These active site differences affect the sensitivity of the respective enzymes to the antibiotics thiolactomycin and cerulenin. Different reaction mechanisms have been proposed for the condensing enzymes. This review covers the recent structural and mechanistic data to see if a unifying hypothesis for the reaction mechanism catalyzed by this important family of enzymes can be established.