cssi/SciSciGPT-SciSciNet huggingface dataset:
Endogenous separation, wage rigidity and the dynamics of unemployment

Abstract Previous attempts to evaluate the Mortensen–Pissarides model rely on either endogenous separation or wage rigidity. In this paper I simulate a version of the Mortensen–Pissarides (MP) model with wage rigidity and endogenous separation. The model is then able to answer a key question in the literature: can wage rigidity and endogenous separation explain the joint dynamics of unemployment, vacancies and wages? I find that it can. The model generates sufficient volatility in unemployment, the separation rate and the finding rate, 75% of the observed volatility in vacancies, and 70% of the Beveridge curve (the negative correlation between unemployment and vacancies). More substantially, the model matches the volatility of the average wage and generates a response of new hires’ wages to productivity and unemployment consistent with key estimates in the literature. I then simulate the model while restricting the separation rate to be constant and show that the model predicts only 70% of the variance of unemployment. I conclude that finding rate fluctuations explain 70% of unemployment fluctuations halfway in between the most prominent estimates in the literature.
Structure and properties of simple molecular systems at very high density

Abstract The use of computer simulations in the study of molecular systems at very high density is reviewed. Applications to the thermodynamics of dense fluid nitrogen and phase transitions in solid oxygen are presented. The effects of changes in the atomic electronic structure on the equation of state of very dense helium are discussed.
A flexible concast-based grouping service

We present a scalable and flexible grouping service based on concast and best-effort single-source multicast. The service assigns participating end systems to specific groups based on application-supplied criteria. Example uses of such a service include peer-to-peer applications that want to group machines that are "near" each other, and reliable multicast services that need to assign receivers to repair groups. Our generic grouping framework relies on concast's many-to-one transport service to efficiently collect and apply the application-specific grouping criteria to the group members' information, and it relies on single-source multicast (i.e., one-to-many communication) to distribute the results to the nodes being grouped. The service can easily be customized to meet the grouping requirements of the application. We present simulation data showing the convergence properties of our grouping service and its effectiveness when applied to the problem of constructing overlay networks.
Ethyl pyruvate: a novel anti‐inflammatory agent

Ethyl pyruvate (EP) is a simple derivative of the endogenous metabolite, pyruvic acid. Treatment with EP has been shown to improve survival and/or ameliorate organ dysfunction in a wide variety of preclinical models of critical illnesses, such as severe sepsis, acute respiratory distress syndrome, acute pancreatitis and stroke. EP was originally regarded as simply a way to administer pyruvate anion, whilst avoiding some of the problems associated with the instability of pyruvate in aqueous solutions. Increasingly, however, it is becoming apparent that certain pyruvate esters, including EP, have pharmacological effects, such as suppression of inflammation, that are quite distinct from those exerted by pyruvate anion. EP has been tested in human volunteers and shown to be safe at clinically relevant doses. It remains to be determined whether EP can be used successfully to treat human diseases.
Naturalism, Formalism, and Supernaturalism: Moral Epistemology and Comparative Ethics

If the much discussed fragmentation of the West meansthat we can seldom hold constructive moral conversations with our near neighbors, why imagine that comparative ethics is feasible as a critical enterprise with a coherent method? How, more specifically, do we understand the relative merits of naturalism, formalism, and supernaturalism as ethical orientations? The author addresses these questions first by examining the meaning of the quoted terms, then by criticizing the inordinate optimism of most naturalisms and formalisms. The article ends by briefly elaborating and defending a supernaturalist conception of Christian love. As a fruit of the Spirit, agape leaves one neither heteronomous nor autonomous, but holy. Such holiness can move one to appreciate, judiciously, cultures different from one's own.
Reconstructing Nonlinear Stochastic Bias from Velocity Space Distortions

We propose a strategy to measure the dark matter power spectrum using minimal assumptions about the galaxy distribution and the galaxy-dark matter cross-correlations. We argue that on large scales the central limit theorem generically assures Gaussianity of each smoothed density field, but not coherence. Asymptotically, the only surviving parameters on a given scale are galaxy variance σ, bias b = Ω0.6/β, and the galaxy-dark matter cross-correlation coefficient r. These can all be determined by measuring the quadrupole and hexadecapole velocity distortions in the power spectrum. Measuring them simultaneously may restore consistency between all β-determinations independent of galaxy type. The leading deviations from Gaussianity are conveniently parameterized by an Edgeworth expansion. In the mildly nonlinear regime, two additional parameters describe the full picture: the skewness parameter s and nonlinear bias b2. They can both be determined from the measured skewness combined with second-order perturbation theory or from an N-body simulation. By measuring the redshift distortion of the skewness, one can measure the density parameter Ω with minimal assumptions about the galaxy formation process. This formalism also provides a convenient parameterization to quantify statistical galaxy formation properties.
Influence of compiler optimizations on system power

Optimizing for energy constraints is of critical importance due to the proliferation of battery-operated embedded devices. Thus, it is important to explore both hardware and software solutions for optimizing energy. The focus of high-level compiler optimizations has traditionally been on improving performance. In this paper, we present an experimental evaluation of several state-of-the-art high-level compiler optimizations on energy consumption, considering both the processor core (datapath) and memory system. This is in contrast to many of the previous works that have considered them in isolation.
Reactions of 2,2‐Dimethylaziridine‐Type Alkylating Agents in Biological Systems II: Comparative Pharmacokinetics in Dogs

Pharmacokinetic studies in dogs were performed with a series of three 2,2‐dimethylaziridine antineoplastic agents. These alkylating agents were relatively unstable in all aqueous media, with half‐lives of 9–15 min in whole canine blood. This finding indicates that the aziridine compounds are capable of undergoing destruction in all biological tissues. A pharmacokinetic analysis of the plasma concentration versus time data was performed using a two‐compartment open model, which includes drug elimination from both compartments. The three aziridine compounds showed similar pharmacokinetic behavior with respect to their loss from plasma, but they exhibited differences in their in vivo release of a potent alkylating intermediate (2,2‐dimethylaziridine) and a second product, which was a strong inhibitor of pseudocholinesterase.
Serial arithmetic techniques

It has recently been suggested that the association of serial-mode functional (arithmetic) units with multi-instruction counter, multiprocessing computing systems may result in highly efficient processing complexes. This follows from the fact of life that in going from parallel to serial realizations of various algorithms the hardware requirements fall much more rapidly than does the speed. Furthermore the speeds of the slower, serial, arithmetic units may be more closely matched to those of memory and to other parts of the system. Thus the need for extra control circuitry, for high-speed registers, queueing circuits and look-ahead control, for example, is reduced and the system's overall cost/performance ratio improved. For appropriate serial configurations then, performance may be improved relative to a parallel system when system costs are to be held constant. Reconfiguration of a fast parallel circuit, for example, can yield a number of slower serial devices which, when kept busy, will increase throughput of the system.
Magnetic properties of lithium ferrite microwave materials

Abstract This report presents a comprehensive review of the magnetic properties of lithium ferrite materials. The fundamental properties are considered first. These include crystal structure, magnetization, magnetocrystalline anisotropy, and magnetostriction. The extrinsic magnetic properties, which are related to microwave applications, are then examined. These include coercive force, remanence, and microwave loss. Finally, a systematic review of the effects of substituents, including titanium, zinc, manganese, cobalt, and bismuth, is presented.
There Is No Tame Triangulation of the Infinite Real Grassmannian

We show that there is no triangulation of the infinite real Grassmannian G(k,R∞) nicely situated with respect to the coordinate axes. In terms of matroid theory, this says there is no triangulation of G(k,R∞) subdividing the matroid stratification. This is proved by an argument in projective geometry, considering a specific sequence of configurations of points in the plane.
Competition of Longitudinal and Transverse Modes in a CW HF Chemical Laser

Abstract : Longitudinal and transverse mode competition in stable and unstable resonators of a single vJ-transition cw HF chemical laser were investigated. Single longitudinal mode operation in a long (greater than 2 meters) resonator was achieved, and asymmetric mode spectra were observed. These observations indicate that there is strong mode competition and a frequency-dependent loss mechanism caused by a limiting aperture and the effect of saturation of anomalous dispersion. From these observations, it is possible to measure the effect of saturation on anomalous dispersion in a high-power chemical laser.
Comets, Impacts, and Atmospheres

We are proposing a model for the delivery of volatiles to the inner planets by icy planetesimals (comets). Laboratory studies of the trapping of gases in ice forming at low temperatures simulate the formation of comet nuclei at various distances from the Sun in the solar nebula. The total gas content as well as the relative proportions of gases trapped in the ice are strong functions of temperature. As they trap N2 inefficiently, all planetesimals formed interior to Neptune are deficient in nitrogen, acquiring values of C/N resembling those found in the inner planet volatile inventories. A mixture of three basic types of comets appears capable of accounting for the observed volatile inventories on Venus, Earth, and Mars, with the caveat that impact erosion is necessary to explain the present condition of the martian atmosphere. The model includes the possibility of several epochs of clement conditions on early Mars. Some tests of these ideas are suggested, including measurements in Jupiter's atmosphere by the Galileo probe.
Generation of Th1 T cell responses directed to a HLA Class II restricted epitope from the Aspergillus f16 allergen

The Aspergillus allergen Asp f16 has been shown to confer protective Th1 T cell-mediated immunity against infection with Aspergillus conidia in murine models. Here, we use overlapping (11-aa overlap with preceding peptide) pentadecapeptides spanning the entire 427-aa coding region of Asp f16 presented on autologous dendritic cells (DC) to evaluate the ability of this antigen to induce Th1 responses in humans. Proliferative responses were induced in five out of five donors, and one line with a high frequency of interferon (IFN)-gamma-producing CD4(+) T cells in response to the complete peptide pool was characterized. This line was cytotoxic to autologous pool-pulsed and Aspergillus culture extract-pulsed targets. Limitation of cytotoxicity to the CD4(+) T cell subset was demonstrated by co-expression of the degranulation marker CD107a in response to peptide pool-pulsed targets. Cytotoxic T lymphocytes (CTL) killed Aspergillus hyphae and CTL culture supernatant killed Aspergillus conidia. By screening 21 smaller pools and individual peptides shared by positive pools we identified a single candidate sequence of TWSIDGAVVRT that elicited responses equal to the complete pool. The defined epitope was presented by human leucocyte antigen (HLA)-DRB1-0301. These data identify the first known Aspergillus-specific T cell epitope and support the use of Asp f16 in clinical immunotherapy protocols to prime protective immune responses to prevent or treat Aspergillus infection in immunocompromised patients.
Selective Oxidation of Butane to Maleic Anhydride on a Vanadium-Phosphorus Oxide Catalyst: Promotional Effects of Zirconium

Abstract This study examines the role of zirconium as a promoter in the selective oxidation of n -butane to maleic anhydride on a vanadium-phosphorus oxide catalyst. Reaction studies show that low levels of zirconium (Zr/V = 0.03) decrease the temperature of maximum yield relative to the unpromoted catalyst. Higher levels of zirconium (Zr/V = 0.13) result in lower yields. 16 O 2 - 18 O 2 exchange measurements show no evidence for oxygen exchange between the gas phase and the bulk lattice at 400°C, in agreement with other studies. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements are combined with the reaction studies to indicate a probable structural role for zirconium as a promoter.
Acoustic waves in the upper mesosphere and lower thermosphere generated by deep tropical convection

[1] A time-dependent, nonlinear, fully compressible, axisymmetric, f-plane, numerical model is used to simulate the propagation of acoustic waves in the mesosphere and thermosphere by intense deep convection in the troposphere. The simulations show that major convective storms in the tropics launch acoustic waves into the mesosphere-thermosphere directly above the storm centers. The principal feature of the overhead acoustic wave field in the period interval of ∼3 to 5 min is a trapped oscillation below about 80 km altitude with a period of ∼5 min and a nearly vertically propagating wave with about a 3-min period above this height. Acoustic oscillations in the troposphere-mesosphere duct have a standing wave character directly over the storm; the oscillations that propagate off vertical mainly reflect off the top and bottom of the duct resulting in a horizontally propagating acoustic field within the duct. The acoustic oscillations that are mainly confined to the troposphere-mesosphere duct persist for about an hour after the storm has ended. The vertically propagating thermospheric acoustic oscillations are waves propagating upward from the thunderstorm source through the stratosphere-mesosphere. These predominantly 3-min waves are strongly driven for ∼30 min after the storm event and weaken with time thereafter. The vertically propagating thermospheric acoustic waves may be the source of the F-region 3-min oscillations. Intense acoustic disturbances directly above thunderstorms may be responsible for localized heating of the thermosphere.
Nickel boride reduction of aryl nitro compounds

Abstract Nickel boride smoothly reduces aryl nitro compounds to the corresponding anilines in the presence of iodo and ortho carboalkoxy groups in contrast to the problematic reductions by other methods.
Enhanced Lipid Diffusion and Mixing in Accelerated Molecular Dynamics

Since biological membranes often contain multiple lipid components, mixed bilayers offer a more realistic environment to study protein-lipid interactions than bilayers composed of a single lipid species. Unfortunately, the slow diffusion of lipid molecules renders the preparation of well-equilibrated mixtures a challenge for conventional molecular dynamics (cMD). Here, we demonstrate that a significant speedup in trans-gauche isomerization and lipid lateral diffusion can be achieved using the enhanced sampling method accelerated molecular dynamics (aMD). Comparison of aMD and cMD simulations of a mixed POPC:DMPC bilayer shows that the two methods produce similar lipid mixing behaviors, with aMD generating a 2-3-fold speedup compared to cMD. Our results represent the first application of aMD on lipid bilayers and provide a guideline for future aMD studies of membrane protein or lipid systems.View Large Image | View Hi-Res Image | Download PowerPoint Slide
CAN THERMAL NONEQUILIBRIUM EXPLAIN CORONAL LOOPS

Any successful model of coronal loops must explain a number of observed properties. For warm (approx. 1 MK) loops, these include: 1. excess density, 2. flat temperature profile, 3. super-hydrostatic scale height, 4. unstructured intensity profile, and 5. 1000-5000 s lifetime. We examine whether thermal nonequilibrium can reproduce the observations by performing hydrodynamic simulations based on steady coronal heating that decreases exponentially with height. We consider both monolithic and multi-stranded loops. The simulations successfully reproduce certain aspects of the observations, including the excess density, but each of them fails in at least one critical way. -Xonolithic models have far too much intensity structure, while multi-strand models are either too structured or too long-lived. Storms of nanoflares remain the only viable explanation for warm loops that has been proposed so far. Our results appear to rule out the widespread existence of heating that is both highly concentrated low in the corona and steady or quasi-steady (slowly varying or impulsive with a rapid cadence). Active regions would have a very different appearance if the dominant heating mechanism had these properties. Thermal nonequilibrium may nonetheless play an important role in prominences and catastrophic cooling e(veen.gts..,coronal rain) that occupy a small fraction of the coronal volume. However, apparent inconsistencies between the models and observations of cooling events have yet to be understood.
Contractibility of the space of rational maps

We define an algebro-geometric model for the space of rational maps from a smooth curve X to an algebraic group G, and show that this space is homologically contractible. As a consequence, we deduce that the moduli space \(\operatorname {Bun}_{G}\) of G-bundles on X is uniformized by the appropriate rational version of the affine Grassmannian, where the uniformizing map has contractible fibers.
VORTICITY AND ANTIVORTICITY IN SUBMICRON FERROMAGNETIC FILMS

The existence of stable or metastable vortex and antivortex states in submicron ferromagnetic films is reviewed. Using standard simulation methods, the dynamics of an antivortex in a permalloy asteroid geometry is explored. As in the case of the vortex in similarly sized permalloy disks and squares, there is a sub-GHz frequency gyrotropic mode of the core of the antivortices, and a rich spin wave spectrum in the multi-GHz range. The spin waves are generated in the simulations by using magnetic pulses similar to those available experimentally, which have been applied to circular and square particles of similar sizes in previous research.
Sustainability analysis for competitive intelligence: Success factors for the new economy

Most Competitive Intelligence professionals are uncomfortable with recommending strategic actions to senior management. We are comfortable with collecting the information and data, putting it together, and doing some level of analysis. We feel we are not trained to take it further. And yet it is critical. Without the ability to recommend actions based on the competitive environment our companies face, CI professionals will remain in the realm of the information provider. (Faye Brill, Ryder Systems)
The Brownian Vacancy Driven Walk

We investigate the lattice walk performed by a tagged member of an infinite "sea" of particles filling a d-dimensional lattice, in the presence of a Brownian vacancy.Particle-particle exchange is forbidden; the only interaction between them being hard core exclusion. The tagged particle, differing from the others only by its tag, moves only when it exchanges places with the hole. In this sense, it is a lattice walk "driven" by the Brownian vacancy. The probability distributions for its displacement and for the number of steps taken, after n-steps of the vacancy, are derived. Surprisingly, none of them is a Gaussian! It is shown that the only nontrivial dimension where the walk is recurrent is d=2.
Local Hydrodynamic Stability of Accretion Disks

We employ a variety of numerical simulations in the local shearing box system to investigate in greater depth the local hydrodynamic stability of Keplerian differential rotation. In particular, we explore the relationship of Keplerian shear to the nonlinear instabilities known to exist in simple Cartesian shear. The Coriolis force is the source of linear stabilization in differential rotation. We exploit the formal equivalence of constant angular momentum flows and simple Cartesian shear to examine the transition from stability to nonlinear instability. The manifestation of nonlinear instability in simple shear flows is known to be sensitive to initial perturbation and the amount of viscosity; marginally (linearly) stable differentially rotating flows exhibit this same sensitivity. Keplerian systems, however, are completely stable; stabilizing Coriolis forces easily overwhelm any destabilizing nonlinear effects. If anything, nonlinear effects speed the decay of applied turbulence by producing a rapid cascade of energy to high wavenumbers where dissipation occurs. We test our conclusions with grid-resolution experiments and by comparing the results of codes with very different diffusive properties. The detailed agreement of the decay of nonlinear disturbances found repeatedly in codes with very different diffusive behaviors strongly suggests that Keplerian stability is not a numerical artifact. The properties of hydrodynamic differential rotation are contrasted with magnetohydrodynamic differential rotation. A kinetic stress tensor couples to the outwardly increasing vorticity, which limits turbulence; a magnetic stress couples to the outwardly decreasing shear, which promotes turbulence. Thus magnetohydrodynamic turbulence is uniquely capable of acting as a turbulent angular momentum transport mechanism in disks.
Cost Effective Synthesis, Processing and Applications of Light-Weight Metallic Materials

(2006). Cost Effective Synthesis, Processing and Applications of Light-Weight Metallic Materials. Materials Technology: Vol. 21, No. 2, pp. 94-101.
Delayed Fragmentation of Acetonitrile upon Short-Pulse UV Irradiation: Possible Role of Long-Lived Superexcited Intermediates,

We have studied fragment emission in the spectral range 200–900 nm, following short‐pulse UV excitation (25 ps, 266 nm, 0.2–10 mJ) of acetonitrile. The dominant components of emission are the CN B 2Σ+→X 2Σ+ violet system and the C2 d 3Πg→a 3Πu Swan system. Emissive CH and NH are also observed. Each of these diatomics is produced with a pressure‐dependent rate. An instrumental risetime of 0.6 ns enabled study of the rise and fall of violet and of Swan emission over the pressure range 0.27–10 Torr. The formation kinetics suggest that there are long‐lived intermediates to the violet and Swan emissive populations. These precursors are not observed in emission. They have zero‐pressure lifetimes of 20 to 30 ns; in collisions with the parent they are removed with large bimolecular rate constants (≳10−9 cm3 s−1). With the use of isotopically labeled acetonitrile, we have established that major fractions of CN B 2Σ+ and of C2 d 3Πg are formed intramolecularly. Further, two channels of intramolecular CN B 2Σ+ produ...
Minimizing storage in implementations of the overlap lattice Dirac operator

The overlap lattice-Dirac operator contains the sign function ∊(H). Recent practical implementations replace ∊(H) by a ratio of polynomials, H Pn(H2)/Qn(H2), and require storage of 2n+2 large vectors. Here I show that one can use only four large vectors at the cost of executing the core conjugate algorithm twice. The slow-down might be less than by a factor of 2, depending on the architecture of the computer one uses.
Management of massive head and neck neurofibromas in children

(Editorial Comment: Management of large debilitating and disfiguring plexiform neurofibroma represent a difficult challenge in clinical practice. The authors illustrate successful surgical management of these deforming lesions in three children.) The neurofibromatoses are genetic disorders primarily affecting cell growth of neural tissues that may lead to tumor growth at any location and at any time. Two distinct forms have been recognized, though variants of these may exist. Neurofibromatosis 1, originally referred to as Von Recklinghausen’s disease (VRD), was first described in 1882. It is a hereditary neural crest phakomatosis occurring in approximately 1 in 4,000 live births. An autosomal dominant disorder with variable penetrance (70%-80%), approximately 50% of cases are thought to occur by spontaneous mutation, giving it the highest rate of any dominantly inherited trait1 The gene for this disease has been localized to chromosome 1 7.2 Neurofibromas may occur anywhere in the head and neck including any of the deep neck spaces. Diagnostic criteria for an individual to be labeled as a Type-l neurofibromatosis are detailed in Table 1. Neurofibromatosis 2 (NF2) is a rarer autosoma1 dominant disorder occurring in about 1 in 50,000 individuals and characterized by eighth nerve and other intracranial and intraspinal
Digital processing of X-ray diffraction patterns from oriented fibers

Abstract Accurate measurement of intensity data from x-ray diffraction patterns of oriented fibers is one of the major difficulties in the determination of polymer structures. Accurate diffraction data are particularly important when discrimination between different, but similar, molecular models is required. Although digital processing of diffraction patterns has provided more accurate data than was obtainable by traditional measurements, many of the methods used have been partly subjective and restricted to well-resolved diffraction patterns. Background is a major source of error in intensity measurement. A general method of two-dimensional background removal has been developed. Objective methods of measuring the intensities of Bragg reflections from x-ray diffraction patterns of polycrystal-line fibers are described. A profile fitting method (which is an extension of the previously reported angular deconvolution procedure) for measuring diffraction data from noncrystalline oriented polymers is also pre...
Molecular Network Analysis of Endometriosis Reveals a Role for c-Jun–Regulated Macrophage Activation

Clinical management of endometriosis is limited by the complex relationship between symptom severity, heterogeneous surgical presentation, and variability in clinical outcomes. As a complement to visual classification schemes, molecular profiles of disease activity may improve risk stratification to better inform treatment decisions and identify new approaches to targeted treatment. We use a network analysis of information flow within and between inflammatory cells to discern consensus behaviors characterizing patient subpopulations. Unsupervised multivariate analysis of cytokine profiles quantified by multiplex immunoassays identified a subset of patients with a shared "consensus signature" of 13 elevated cytokines that was associated with common clinical features of endometriosis, but was not observed among patient subpopulations defined by morphologic presentation alone. Enrichment analysis of consensus markers reinforced the primacy of peritoneal macrophage infiltration and activation, which was demonstrably elevated in ex vivo cultures. Although familiar targets of the nuclear factor κB family emerged among overrepresented transcriptional binding sites for consensus markers, our analysis provides evidence for an unexpected contribution from c-Jun, c-Fos, and AP-1 effectors of mitogen-associated kinase signaling. Their crucial involvement in propagation of macrophage-driven inflammatory networks was confirmed via targeted inhibition of upstream kinases. Collectively, these analyses suggest a clinically relevant inflammatory network that may serve as an objective measure for guiding treatment decisions for endometriosis management, and in the future may provide a mechanistic endpoint for assessing efficacy of new agents aimed at curtailing inflammatory mechanisms that drive disease progression.
On the closure of the complex symmetric operators: Compact operators and weighted shifts

Abstract We study the closure CSO ¯ of the set CSO of all complex symmetric operators on a separable, infinite-dimensional, complex Hilbert space. Among other things, we prove that every compact operator in CSO ¯ is complex symmetric. Using a construction of Kakutani as motivation, we also describe many properties of weighted shifts in CSO ¯ \ CSO . In particular, we show that weighted shifts which demonstrate a type of approximate self-similarity belong to CSO ¯ \ CSO . As a byproduct of our treatment of weighted shifts, we explain several ways in which our result on compact operators is optimal.
Use of CCDs in the Time Projection Chamber

The Time Projection Chamber produces 3-dimensional information about the multiple tracks of reaction products produced by e+ e-collisions at the center of the chamber. Two dimensions (r,o) result from processing signals from proportional wires and induction pads (a total of 17,000 signals) mounted at the end planes. The third (axial) dimension is obtained by measuring the drift time of ionization from the particle tracks to the end planes. To achieve this, all wire and pad signals (suitably shaped to about 500 ns width) are stored in Charge Coupled Devices (CCDs) which, at any moment, hold 45.5 ?s of signal history clocked in at a sampling rate of 10 MHz. About 40 ?s after a master trigger, the history is frozen by stopping the clocking action, and a slow clock mode (20 kHz) is initiated to read out the stored samples which are then digitized (9 bits) and processed by an on-line computer. A total of 17,000 channels × 455 samples (each digitized to 9 bit accuracy) is stored in the CCDs (i.e., about 70M bits) for each event. This paper describes the pulse shaping philosophy, the design of the CCD units, the drivers and the testing procedures.
Bottom-Fishing and Declining Prices in Sequential Auctions

Abstract We study standard sequential auctions, in which the seller chooses the order of sale, and right-to-choose auctions, in which the winner chooses her preferred item from the remaining items. Empirically, prices in sequential auctions tend to decline, and sellers often hold right-to-choose auctions. In our setting, the right-to-choose format guarantees declining prices and efficiency. In the standard auction, a buyer may submit a low bid for the first item ("bottom-fishing") despite its being her less-preferred item. An example shows that the standard auction has declining prices, is inefficient, and gives lower expected revenue than the right-to-choose. Journal of Economic Literature Classification Numbers: D44, D82.
Data-Efficient Quickest Change Detection in Minimax Settings

The classical problem of quickest change detection is studied with an additional constraint on the cost of observations used in the detection process. The change point is modeled as an unknown constant, and minimax formulations are proposed for the problem. The objective in these formulations is to find a stopping time and an ON-OFF observation control policy for the observation sequence, to minimize a version of the worst possible average delay, subject to constraints on the false alarm rate and the fraction of time observations are taken before change. An algorithm called DE-CuSum is proposed and is shown to be asymptotically optimal for the proposed formulations, as the false alarm rate goes to zero. Numerical results are used to show that the DE-CuSum algorithm has good tradeoff curves and performs significantly better than the approach of fractional sampling, in which the observations are skipped using the outcome of a sequence of coin tosses, independent of the observation process. This study is guided by the insights gained from an earlier study of a Bayesian version of this problem.
Farm programs and climate change

The view that the agricultural sector could largely offset any negative impacts of climate change by altering production practices assumes the government will not create disincentives for farmers to adapt. U.S. farm programs, however, often discourage such obvious adaptations as switching crops, investing in water conserving technologies, and entry or exit. We outline a simple portfolio model describing producer decision making: we then use this framework to assess how specific U.S. farm programs might affect adaption to climate change. Three future climate scenarios are considered and in each the present structure of U.S. farm programs discourages adaptation.
Chondrite chronology by initial 87Sr/86Sr in phosphates?

New data are presented on Rb-Sr isotope analyses of phosphates from nine ordinary chondrites, including accurate identification of initial Sr-87/Sr-86. The initial Sr-87/Sr-86 ratios found in this study were generally significantly higher than the more primitive initial Sr-87/Sr-86 ratios inferred for carbonaceous chondrite refractory inclusions, basaltic achondrites, or bulk ordinary chondrites. Such elevation of initial Sr-87/Sr-86 is generally considered to reflect isotopic redistribution during metamorphism. However, in this study, no evident correlation was found between the phosphate initial Sr-87/Sr-86 compositions and the metamorphic grade. Two possible alternative hypotheses for high initial Sr-87/Sr-86 ratios are considered.
Uncertainties on the measurements of the top mass at a future e + e - collider

The uncertainties due to limited knowledge of the multi-hadron final state on the measurements of the top mass at future linear colliders are discussed. This study is performed for $e^+e^-\to t\bar{t}$ annihilation events at the center-of-mass energy of s 1/2 =500 GeV using Monte Carlo models tuned to LEP experiments. The uncertainties are determined for the all-hadronic top-decay mode as well as for the lepton-plus-jets channel.
Classical Electrostatics in Biology and Chemistry

A major revival in the use of classical electrostatics as an approach to the study of charged and polar molecules in aqueous solution has been made possible through the development of fast numerical and computational methods to solve the Poisson-Boltzmann equation for solute molecules that have complex shapes and charge distributions. Graphical visualization of the calculated electrostatic potentials generated by proteins and nucleic acids has revealed insights into the role of electrostatic interactions in a wide range of biological phenomena. Classical electrostatics has also proved to be successful quantitative tool yielding accurate descriptions of electrical potentials, diffusion limited processes, pH-dependent properties of proteins, ionic strength-dependent phenomena, and the solvation free energies of organic molecules.
SPIKE DECOMPOSITION TECHNIQUE: MODELING AND PERFORMANCE TESTS

We develop an automated technique for fitting the spectral components of solar microwave spike bursts, which are characterized by narrowband spectral features. The algorithm is especially useful for periods when the spikes occur in densely packed clusters, where the algorithm is capable of decomposing overlapping spike structures into individual spectral components. To test the performance and applicability limits of this data reduction tool, we perform comprehensive modeling of spike clusters characterized by various typical bandwidths, spike densities, and amplitude distributions. We find that, for a wide range of favorable combinations of input parameters, the algorithm is able to recover the characteristic features of the modeled distributions within reasonable confidence intervals. Having model-tested the algorithm against spike overlap, broadband spectral background, noise contamination, and possible malfunction of some spectral channels, we apply the technique to a spike cluster recorded by the Chinese Purple Mountain Observatory (PMO) spectrometer, operating above 4.5 GHz. We study the variation of the spike distribution parameters, such as amplitude, bandwidth, and related derived physical parameters, as a function of time. The method can be further applied to observations from other instruments and to other types of fine structures.
Dynamics of cultural transmission in Native Americans of the high Great Plains.

Culture is a phenomenon shared by all humans. Attempts to understand how dynamic factors affect the origin and distribution of cultural elements are, therefore, of interest to all humanity. As case studies go, understanding the distribution of cultural elements in Native American communities during the historical period of the Great Plains would seem a most challenging one. Famously, there is a mixture of powerful internal and external factors, creating-for a relatively brief period in time-a seemingly distinctive set of shared elements from a linguistically diverse set of peoples. This is known across the world as the “Great Plains culture.” Here, quantitative analyses show how different processes operated on two sets of cultural traits among nine High Plains groups. Moccasin decorations exhibit a pattern consistent with geographically-mediated between-group interaction. However, group variations in the religious ceremony of the Sun Dance also reveal evidence of purifying cultural selection associated with historical biases, dividing down ancient linguistic lines. The latter shows that while the conglomeration of “Plains culture” may have been a product of merging new ideas with old, combined with cultural interchange between groups, the details of what was accepted, rejected or elaborated in each case reflected preexisting ideological biases. Although culture may sometimes be a “melting pot,” the analyses show that even in highly fluid situations, cultural mosaics may be indirectly shaped by historical factors that are not always obvious.
THE CANDIDATE INTERMEDIATE-MASS BLACK HOLE IN THE GLOBULAR CLUSTER M54

Ibata et al. reported evidence for density and kinematic cusps in the Galactic globular cluster M54, possibly due to the presence of a 9400 M ☉ black hole. Radiative signatures of accretion onto M54's candidate intermediate-mass black hole (IMBH) could bolster the case for its existence. Analysis of new Chandra and recent Hubble Space Telescope astrometry rules out the X-ray counterpart to the candidate IMBH suggested by Ibata et al. If an IMBH exists in M54, then it has an Eddington ratio of L(0.3-8 keV)/L(Edd) < 1.4 × 10–10, more similar to that of the candidate IMBH in M15 than that in G1. From new imaging with the NRAO Very Large Array, the luminosity of the candidate IMBH is L(8.5 GHz) < 3.6 × 1029 erg s–1 (3σ). Two background active galaxies discovered toward M54 could serve as probes of its intracluster medium.
Temperature and Pressure Measurement Techniques for an Advanced Turbine Test Facility

A high pressure, high-temperature turbine test facility constructed for use in turbine cooling research is described. Several recently developed temperature and pressure measuring techniques are used in this facility. The measurement techniques, their status, previous applications and some results are discussed. Noncontact surface temperature measurements are made by optical methods. Radiation pyrometry principles combined with photoelectric scanning are used for rotating components and infrared photography for stationary components. Contact (direct) temperature and pressure measurements on rotating components are expected to be handled with an 80 channel rotary data package which mounts on and rotates with the turbine shaft at speeds up to 17,500 rpm. The data channels are time-division multiplexed and converted to digital words in the data package. A rotary transformer couples power and digital data to and from the shaft.
Inference With Interference Between Units in an fMRI Experiment of Motor Inhibition

An experimental unit is an opportunity to randomly apply or withhold a treatment. There is interference between units if the application of the treatment to one unit may also affect other units. In cognitive neuroscience, a common form of experiment presents a sequence of stimuli or requests for cognitive activity at random to each experimental subject and measures biological aspects of brain activity that follow these requests. Each subject is then many experimental units, and interference between units within an experimental subject is, likely, in part because the stimuli follow one another quickly and in part because human subjects learn or become experienced or primed or bored as the experiment proceeds. We use a recent functional magnetic resonance imaging (fMRI) experiment concerned with the inhibition of motor activity to illustrate and further develop recently proposed methodology for inference in the presence of interference. A simulation evaluates the power of competing procedures.
An alternative specification for intraday simultaneity in spot and futures markets

Abstract Recent research demonstrates the importance of modeling intraday dynamic price relationships using high-frequency transactions data as simultaneous equations models to account for simultaneity in futures and spot prices. Motivated by theoretical and econometric considerations, this paper presents an alternative specification that accounts for both simultaneity and prior deviations from any long-run pricing association between the two price series. A comparison of the specification to prior work indicates that for the specific data examined, prior specifications fail to account for a significant component in these market microstructure relationships. Further, prior models are not robust to the misspecification, and when it is considered, an alternative view of intraday simultaneity in stock index futures markets is provided.
Gloss Investigations Using Reflected Images of a Target Pattern

A target pattern of concentric rings varying from fine lines to broad bands has been placed in the open face of a desk lamp. This luminous target is useful in the study of the gloss characteristics of the more glossy surfaces. The lines and bands of various sizes in the target provide means for studying surfaces of a wide range of “distinctness-of-reflected-image” gloss. Records may be made of which lines and bands are visible by reflection from different surfaces. Such records serve as permanent gloss values for the different surfaces studied. The dark areas of the target immediately adjacent to the luminous areas provide ideal conditions for the identification of surface “bloom.” The best gloss differentiations are made when the lamp is used in a darkened room so that the luminous pattern is the only source of light illuminating the surfaces inspected. Photographic records of gloss and unusual gloss effects are discussed.
Exploring the role of citizen journalism in slum improvement: the case of ‘Voice of Kibera’

This paper explores the role of citizen journalism in the improvement of slums through the Voice of Kibera (VoK) case study. To meet the research objectives, both qualitative and quantitative methods are applied. The study used content analysis, a survey and interview techniques. It concluded that citizen journalism in the VoK uses a participatory, bottom-up approach, with the residents taking a lead role in the production and consumption of news, and that it plays its part in improving the lives of people in Kibera, contributing to governance and processes of democracy. The core development values of participation and empowerment are central to this study, which examines how these values are being impacted on by information technology interventions in the communications area. The research also concludes that citizen journalism may be sustainable if it is financed, promoted, resourced with professional journalists, equipped with new technologies and citizens continue to participate. Lack of cooperation from the audience, finance both for the running of the project, salary and technical problems were cited as the major challenges of citizen journalism.
A Determination of the Hubble Constant from Cepheid Distances and a Model of the Local Peculiar Velocity Field

We present a measurement of the Hubble constant based on Cepheid distances to 27 galaxies within 20 Mpc. We take the Cepheid data from published measurements by the Hubble Telescope Key Project on the Distance Scale (H0KP). We calibrate the Cepheid period-luminosity (PL) relation with data from over 700 Cepheids in the LMC obtained by the OGLE collaboration; we assume an LMC distance modulus of 18.50 mag (dLMC = 50.1 kpc). Using this PL calibration, we obtain new distances to the H0KP galaxies. We correct the redshifts of these galaxies for peculiar velocities using two distinct velocity field models: the phenomenological model of Tonry et al. and a model based on the IRAS density field and linear gravitational instability theory. We combine the Cepheid distances with the corrected redshifts for the 27 galaxies to derive H0, the Hubble constant. The results are H0 = 85 ± 5 km s-1 Mpc-1 (random error) at 95% confidence when the IRAS model is used, and 92 ± 5 km s-1 Mpc-1 when the phenomenological model is used. The IRAS model is a better fit to the data, and the Hubble constant it returns is more reliable. Systematic error stems mainly from LMC distance uncertainty, which is not directly addressed by this paper. Our value of H0 is significantly larger than that quoted by the H0KP, H0 = 71 ± 6 km s-1 Mpc-1. Cepheid recalibration explains ~30% of this difference, and velocity field analysis accounts for ~70%. We discuss in detail possible reasons for this discrepancy and future studies needed to resolve it.
Aerodynamics of a Jet in the Vortex Wake of a Wing

Results of a low-speed experimental investigation of jet behavior in the trailing vortex wake of a wing are presented. The effects of varying jet-to-freestream velocity ratio and vortex-wake strength on the downstream evolution of the flowfield are quantified via three-dimensional hot-wire anemometry surveys. Under conditions encountered in powered flight, especially flow states characteristics of takeoff, landing, and maneuvering of a vehicle, the jet is found to undergo severe distortion within a very short distance from the nozzle exit. The interaction of the jet and the wing vortices generates additional vortical structures. Spreading and decay of the jet are shown to be governed predominantly by the interaction of the vortices