Miracle-dz/UniFAR-FTUs huggingface dataset:
THE INFORMATION BOUND OF A DYNAMIC PANEL LOGIT MODEL WITH FIXED EFFECTS

In this paper, I calculate the semiparametric information bound in two dynamic panel data logit models with individual specific effects. In such a model without any other regressors, it is well known that the conditional maximum likelihood estimator yields a √n-consistent estimator. In the case where the model includes strictly exogenous continuous regressors, Honoré and Kyriazidou (2000, Econometrica 68, 839–874) suggest a consistent estimator whose rate of convergence is slower than √n. Information bounds calculated in this paper suggest that the conditional maximum likelihood estimator is not efficient for models without any other regressor and that √n-consistent estimation is infeasible in more general models.
Comparative analysis of closed and open-cervix canine pyometra*

Canine pyometra is the most common uterine disease in intact, sexually mature female dogs. The disease is broadly classified as open and closed type, based on the patency of cervix. The study was conducted to evaluate the changes in clinical, physiological and haemato-biochemical parameters in open and closed-cervix pyometra. Physiological parameters were not altered among pyometra-affected dogs. Vomiting, dehydration and dullness were more frequently noticed in open-cervix pyometra cases. Significantly higher total leucocyte count and band cell per cent and significantly lower total erythrocyte count was recorded among dogs with open-cervix pyometra than closed-cervix pyometra. The present finding is contradictory to most of the previous reports.
Magnetic fields, pressures, and thermally unstable gas in prominent H I shells

B(parallel) from the Zeeman effect has been measured for the 21 cm line in emission in a number of morphologically prominent H I shells. The H I structures are in fact filamentary instead of sheetlike. B(parallel) is typically about 6.4 micro-G. If estimates of n(H I) are correct, magnetic pressure dominates thermal gas pressure by a factor of about 67, and linewidths are somewhat smaller than the Alfven velocity. B(parallel) as derived from the Zeeman effect does not correlate with Faraday rotation. A similar lack of correlation is found when comparing optical and diffuse synchrotron polarization in the North Polar Spur. Thus, the magnetic field is oriented differently in different types of region, with little if any correlation. 35 references.
Multi-wavelength and polarimetric observations of Sagittarius A*

We summarize the results of some of the latest NIR/sub-millimeter/X-ray observing campaigns. Those include the latest simultaneous observations as well as the most recent results from VLT NACO observations of polarized NIR, flare emission of Sgr A*. We interpret the new NIR, polarimetry results using a model in which spots are on relativistic orbits around Sgr A*, which is associated with the massive 3.6 million solar mass black hole at the Galactic Center. In the NIR, the observations have been carried out using the NACO adaptive optics (AO) instrument at the European Southern Observatory's Very Large Telescope. In the X-ray and radio domains we used the ACIS-I instrument aboard the Chandra X-ray Observatory and the Submillimeter Array on Mauna Kea, Hawaii, as well as the Very Large Array in New Mexico, respectively.
Vanishing of the Edwards-Anderson order parameter in two- and three-dimensional Ising spin glasses

The nature of the freezing process in two- and three-dimensional Ising spin glasses with bonds Jij=+or-J has been investigated. Monte Carlo simulations indicate that the characteristic cusp in the susceptibility chi is a non-equilibrium phenomenon resulting from the finite observation times available for the computation of chi (or its experimental measurement). This picture of the freezing process, which is illustrated by explicit calculation for the one-dimensional Ising spin glass, implies chi =1/kBT for all temperatures, or that the Edwards-Anderson order parameter q vanishes. Investigation of the ground states of certain periodic models in two and three dimensions show that every spin belongs to a finite cluster which may be turned over with no cost of energy, so that q is rigorously zero for such models. It is argued that this result holds also for the fully random models.
On a solvable system of rational difference equations

We show that the following system of difference equationswhere , , , and sequences , , and are real, can be solved in closed form. For the case when the sequences , , and are constant and , we apply obtained formulas in the investigation of the asymptotic behaviour of well-defined solutions of the system. We also find domain of undefinable solutions of the system. Our results considerably extend and improve some recent results in the literature.
Accounting for Intrinsic Nonlinearity in Nonlinear Regression Parameter Inference Regions

Joint confidence and likelihood regions for the parameters in nonlinear regression models can be defined using the geometric concepts of sample space and solution locus. Using a quadratic approximation to the solution locus, instead of the usual linear approximation, it is shown that these inference regions correspond to ellipsoids on the tangent plane at the least squares point. Accurate approximate inference regions can be obtained by mapping these ellipsoids into the parameter space, and measures of the effect of intrinsic nonlinearity on inference can be based on the difference between the tangent plane ellipsoids and the sphere which would be obtained using a linear approximation.
A high‐quality reprocessed ground‐based GPS dataset for atmospheric process studies, radiosonde and model evaluation, and reanalysis of HyMeX Special Observing Period

In the framework of the Hydrological cycle in the Mediterranean Experiment (HyMeX) project, measurements from more than 1000 ground‐based Global Positioning System (GPS) receivers located in the northwestern Mediterranean area are reprocessed using a single piece of GPS software for the period from 1 September 2012 to 31 March 2013. A special screening procedure is developed for the removal of outliers in the GPS Zenith Total Delay (ZTD) data. ZTD data are converted to integrated water vapour (IWV) using surface pressure information from an AROME‐WMED operational analysis. The reprocessed ZTD and IWV data are used to assess the accuracy of the near‐real time E‐GVAP ZTD data assimilated in operational numerical weather prediction systems and to validate the IWV data from the AROME‐WMED operational analysis and AROME‐WMED reanalysis 1, and from radiosonde observations. The mean differences between E‐GVAP and reprocessed ZTD data are not negligible and lie in the range from −3 to +3 mm. The standard deviations of differences are between 4 and 8 mm. The comparisons of IWV from AROME‐WMED analyses and the reprocessed GPS data show high quality of the analyses where operational GPS data are assimilated and lower quality where no GPS data are assimilated. Small but significant biases are found in the radiosonde data during daytime (−0.5 to +1.4 kg m−2), but their origin is not determined so far. Thanks to the high spatial density of the reprocessed GPS stations, both the large‐scale and small‐scale variations in IWV can be documented. The case of HyMeX Intensive Observing Period 8 is presented as an example of a heavy precipitation event. This work suggests that improved quality of the humidity fields can be expected of the future AROME‐WMED reanalysis 2 as a result of the assimilation of the reprocessed GPS data.
Aharonov–Bohm effect in scattering by a chain of point‐like magnetic fields

According to the Aharonov–Bohm effect, magnetic potentials have a direct significance to the motion of particles in quantum mechanics. We study this quantum effect through the scattering by several point-like magnetic fields at large separation in two dimensions. We derive the asymptotic formula for scattering amplitudes as the distances between centers of fields go to infinity. The result heavily depends on the location of centers. A special emphasis is placed on the case of scattering by fields with centers on an even line. The obtained formula depends on fluxes of fields and on ratios of distances between adjacent centers. We figure the approximate values of differential cross sections to see how the pattern of interferences changes with flux parameters.
Parameter sampling capabilities of sequential and simultaneous data assimilation: II. Statistical analysis of numerical results

We assess and compare parameter sampling capabilities of one sequential and one simultaneous Bayesian, ensemble-based, joint state-parameter (JS) estimation method. In the companion paper, part I (Fossum and Mannseth 2014 Inverse Problems 30 114002), analytical investigations lead us to propose three claims, essentially stating that the sequential method can be expected to outperform the simultaneous method for weakly nonlinear forward models. Here, we assess the reliability and robustness of these claims through statistical analysis of results from a range of numerical experiments. Samples generated by the two approximate JS methods are compared to samples from the posterior distribution generated by a Markov chain Monte Carlo method, using four approximate measures of distance between probability distributions. Forward-model nonlinearity is assessed from a stochastic nonlinearity measure allowing for sufficiently large model dimensions. Both toy models (with low computational complexity, and where the nonlinearity is fairly easy to control) and two-phase porous-media flow models (corresponding to down-scaled versions of problems to which the JS methods have been frequently applied recently) are considered in the numerical experiments. Results from the statistical analysis show strong support of all three claims stated in part I.
Uncommon Distribution of C20 and C21 Tricyclic Terpanes in Niger Delta Crude Oils

C20 and C21 tricyclic terpanes were investigated in crude oils from Niger Delta, Nigeria. From comparison of the mass chromatograms (m/z 191) of two crude oil samples (CEN-21 and WST-69) with related literatures on tricyclic terpanes which eluted from the gas chromatography (GC) within certain retention time, 12 peaks were selected. Peaks 1 - 5 were selected as C20 tricyclic terpane isomers (TR20a-e) and peaks 6 - 12 selected as C21 tricyclic terpanes (TR21a-g). This distribution is usually as crude oils show a single peak each and indicate the distribution of C20 and C21 tricyclic terpanes in the Niger Delta crude oils is uncommon. Total abundances showed the C20 and the C21 tricyclic terpanes were more in CEN-21 than WST-69 with ratios of 3.07 and 1.84, respectively, with TR20a, TR20b, TR20d and TR21d being the most abundant isomers in both oil samples. These abundances indicate CEN-21 was thermally more mature than WST-69 and that the C20 tricyclic terpanes were generated more than the C21 tricyclic terpanes with increasing thermal maturity of the crude oils. Significant similarities observed in the normalized composition profiles and 66 derived ratios suggest the Niger Delta crude oil samples were genetically related and were predominantly derived from terrigenous Tertiary deltaic petroleum systems. Some differences observed in the composition profile and derived ratios indicate minor input from a different source, depositional environment and/or maturity level and are suggestive as indicators for evaluation, correlation and/or discrimination of the Niger Delta crude oils.
Optimal control of probability density functions of stochastic processes

Abstract A Fokker‐Planck framework for the formulation of an optimal control strategy of stochastic processes is presented. Within this strategy, the control objectives are defined based on the probability density functions of the stochastic processes. The optimal control is obtained as the minimizer of the objective under the constraint given by the Fokker‐Planck model. Representative stochastic processes are considered with different control laws and with the purpose of attaining a final target configuration or tracking a desired trajectory. In this latter case, a receding‐horizon algorithm over a sequence of time windows is implemented.
Effect of Particle Viscosity on Propagation of Sound in Suspensions and Emulsions

The effect of particle viscosity, when it is at least one order of magnitude greater than that of the suspending medium, has been included in the formula, existing in the literature, for the velocity of sound in suspensions or emulsions. The corresponding coefficient of viscous absorption and cross section for scattering of sound energy have also been calculated. The hydrodynamic dispersion of the velocity of sound, due to the frequency‐dependent nature of the viscous interaction between the particles and the suspending medium, has been shown to exist in suspensions or emulsions.
Synthesizing Activities and Interactions in the Concept of a Mechanism*

Stuart Glennan, and the team of Peter Machamer, Lindley Darden, and Carl Craver have recently provided two accounts of the concept of a mechanism. The main difference between these two versions rests on how the behavior of the parts of the mechanism is conceptualized. Glennan considers mechanisms to be an interaction of parts, where the interaction between parts can be characterized by direct, invariant, change‐relating generalizations. Machamer, Darden, and Craver criticize traditional conceptualizations of mechanisms which are based solely on parts interacting and introduce a new concept—activity. This essay is an attempt at carving out a relationship between these two philosophical interpretations of a mechanism. I will claim that, rather than being in conflict, Glennan's concept of interaction and Machamer, Darden, and Craver's notion of activity actually complement one another, each emphasizing a missing element of the other.
Linewidth dependence of grain structure and stress in damascene Cu lines

Damascene Cu interconnects show significant differences in both their microstructural and stress behavior as compared to those of Al interconnects patterned using the etching process. Thermal stresses build up during the successive thermal cycles due to the differences in the coefficients of thermal expansion of the component materials. Other than these thermal stresses, growth stresses originating from grain growth develop in damascene Cu interconnects as well. In this study, the linewidth dependence of the stress in damascene Cu was examined experimentally, as well as by numerical simulation. The stresses of damascene Cu with widths ranging from 0. 13to2μm were measured using x-ray diffraction, and the measured hydrostatic stress was found to increase with increasing linewidth, in contrast to the typical behavior of Al interconnects. Microstructure analysis using transmission electron microscopy revealed that the grain sizes increased with increasing line dimensions. The increase in stress in the interco.
Radio continuum emission from winds, chromospheres, and coronae of cool giants and supergiants

In this paper we present the results of a sensitive VLA radio continuum survey at 6 cm of 39 of the nearest, single cool giants and supergiants with spectral types in the range G0--M5. We discuss our findings in the context of the various mechanisms that might be producing radio emission in these cool stars. We have definitely detected four K and M giants ( Her, Boo, rho Per, and Gem) and probably detected a fifth ( US UMi) at flux levels of 0.1--1.0 mJy. We believe that in all five of these cases the radio emission is thermal emission from cool stellar winds. We have made additional 2 cm observations of several stars, including the four stars definitely detected at 6 cm. We have derived spectral indices for Boo, Her, and rho Per of 0.80, 0.84, and 0.95, respectively, that are close to the 0.6 value predicted by standard stellar wind models in the optically thick regime. An additional cool giant ( Tau) was detected only at 2 cm, implying a spectral index of > or =0.87. None of the coronal or hybrid-chromosphere giants observed were detected in this study, with the exception of Aur, a 0.2 mJy radiomore » source at 6 cm, which is in fact a widely separated, long-period (P/sub orb/approx.104/sup d/) RS CVn system containing two cool giant stars. In this case, we believe that the 6 cm radio emission is optically thin, thermal emission from the corona(e) of one or both of the components, since the radio-emission measure is consistent with that of the observed x-ray emission. « less
Atmospheric Response to Mesoscale Sea Surface Temperature Anomalies: Assessment of Mechanisms and Coupling Strength in a High-Resolution Coupled Model over the South Atlantic*

Many aspects of the coupling between the ocean and atmosphere at the mesoscale (on the order of 20–100 km) remain unknown. While recent observations from the Southern Ocean revealed that circular fronts associated with oceanic mesoscale eddies leave a distinct imprint on the overlying wind, cloud coverage, and rain, the mechanisms responsible for explaining these atmospheric changes are not well established. Here the atmospheric response above mesoscale ocean eddies is investigated utilizing a newly developed coupled atmosphere–ocean regional model [Consortium for Small-Scale Modeling–Regional Ocean Modelling System (COSMO-ROMS)] configured at a horizontal resolution of ~10 km for the South Atlantic and run for a 3-month period during austral winter of 2004. The model-simulated changes in surface wind, cloud fraction, and rain above the oceanic eddies are very consistent with the relationships inferred from satellite observations for the same region and time. From diagnosing the model’s momentum balance, it is shown that the atmospheric imprint of the oceanic eddies are driven by the modification of vertical mixing in the atmospheric boundary layer, rather than secondary flows driven by horizontal pressure gradients. This is largely due to the very limited ability of the atmosphere to adjust its temperature over the time scale it takes for an air parcel to pass over these mesoscale oceanic features. This results in locally enhanced vertical gradients between the ocean surface and the overlying air and thus a rapid change in turbulent mixing in the atmospheric boundary layer and an associated change in the vertical momentum flux.
Dekametric and hectometric observations of Jupiter from the RAE-1 satellite

Analysis of RAE-1 satellite data has revealed the presence of radio bursts from Jupiter in the frequency range from 4700 kHz to 450 kHz. Variations in the activity with respect to the planet's system III longitude are presented at seven frequencies. A merge of ground-based and satellite-acquired data indicates that the long-sought-for peak in Jupiter's low-frequency flux spectrum occurs at about 8 MHz.
Celt reversals: a prototype of chiral dynamics

A physically transparent and mathematically streamlined derivation is presented for a third-order nonlinear dynamical system that describes the curious chiral reversals of a celt (rattleback). The system is integrable, and its solutions are periodic, showing an infinite succession of spin reversals. Inclusion of linear dissipation allows any given number of reversals, and a typical celt's observed behaviour is well captured by tuning the dissipation parameters.
Inverse Eigenvalue Problem for Constructing a Kind of Acyclic Matrices with Two Eigenpairs

We investigate an inverse eigenvalue problem for constructing a special kind of acyclic matrices. The problem involves the reconstruction of the matrices whose graph is an m-centipede. This is done by using the (2m − 1)st and (2m)th eigenpairs of their leading principal submatrices. To solve this problem, the recurrence relations between leading principal submatrices are used.
Ultraluminous infrared galaxies and the origin of quasars

An evolutionary connection between ultraluminous infrared galaxies and quasars is deduced from the observations of all 10 infrared galaxies with luminosities L(8-1000 μm) ≥ 10^(12) L⊙, taken from a flux-limited sample of infrared bright galaxies. Images of the infrared galaxies show that nearly all are strongly interacting merger systems with exceptionally luminous nuclei. Millimeter-wave CO observations show that these objects typically contain 0.5-2 x 10^(10) M⊙ of H_2. Optical spectra indicate a mixture of starburst and active galactic nucleus (AGN) energy sources, both of which are apparently fueled by the tremendous reservoir of molecular gas. It is proposed that these ultraluminous infrared galaxies represent the initial, dust-enshrouded stages of quasars. Once these nuclei shed their obscuring dust, allowing the AGN to visually dominate the decaying starburst, they become optically selected quasars. The origin of quasars through the merger of molecular gas-rich spiral galaxies can account for both the increased number of high-luminosity quasars at large redshift, when the universe was smaller and gas supplies less depleted, and the observed "redshift-cutoff" of quasars which represents the epoch after galaxy formation when the first collisions occur.
Origin of the excitation of the Galactic center

Near-infrared imaging and spectroscopy of the infrared cluster in the central parsec of the galaxy have been obtained. Very-high resolution images of IRS 16 allow an upper limit of 10 percent to be placed to the contribution to the energetics in this region by Sgr A-asterisk. However, the very blue colors of at least five components of IRS 16 suggest that they together could power the region. A deep image at 1.25 micron detects at least three of the sources bright at 10 micron, demonstrating that these objects contain self-luminous cores. Constraints on the temperatures of these cores are placed with infrared spectroscopy, and they appear to be too hot and bright in the near-infrared to be single stars. These cores may also contribute significantly to the overall luminosity of the central parsec. 48 references.
Two-satellite observations of substorm injections at geosynchronous orbit

Energetic particle and plasma measurements from three fairly closely spaced geosynchronous satellites are used to examine the simultaneous behavior of substorm particle injections at spatially separated locations. A total of 43 injection events are identified as dispersionless at two or more satellites. The observations confirm that the ion and electron injection regions are spatially offset in the azimuthal direction, as previously deduced statistically from single-satellite observations and revealed by test-particle trajectories in MHD simulations of geomagnetic tail reconnection. The two-spacecraft observations show further that the injection regions for both ions and electrons expand azimuthally in both the eastward and westward directions over a timescale of several minutes. The observed expansion rates are comparable to expansion rates derived from the test particle/MHD simulations, lending further support to the identification of such reconnection as the ultimate cause of substorm particle injections.