Coma imaging of comet P/Brorsen-Metcalf at Calar Alto in late July to mid August 1989

Comet P/Brorsen-Metcalf was observed on 1989/07/28+30 and on 1989/08/04+12(+14) with the 3.5 m telescope and the 0.8 m Schmidt camera at Calar Alto/Spain. The images exhibit a narrow plasma tail pointing into anti-solar direction. On 1989/07/30 a triple tail was found which can be interpreted as tail ray event. The coma isophotes show prominent asymmetries with the nucleus located on the tailward side of the isophote foci and with a slightly higher brightness in the Northern Hemisphere of the coma. A strong curved jet feature was detected in the coma on 1989/07/30. The jet extended at least 30,000 km into the sunward coma hemisphere. The rotation period of about 1.3 days, estimated from the curvature of the coma jet, needs verification by other observations

Surface photometry of new nearby dwarf galaxies

We present CCD surface photometry of 16 nearby dwarf galaxies, many of which were only recently discovered. Our sample comprises both isolated galaxies and galaxies that are members of nearby galaxy groups. The observations were obtained in the Johnson B and V bands (and in some cases in Kron-Cousins I). We derive surface brightness profiles, total magnitudes, and integrated colors. For the 11 galaxies in our sample with distance estimates the absolute B magnitudes lie in the range of -10>Mb>-13. The central surface brightness ranges from 22.5 to 27.0 mag/sq.arcsec. Most of the dwarf galaxies show exponential light profiles with or without a central light depression. Integrated radial color gradients, where present, appear to indicate a more centrally concentrated younger population and a more extended older population.Comment: accepted by A&

Seismic Response to Injection Well Stimulation in a High-Temperature, High-Permeability Reservoir

Fluid injection into the Earth's crust can induce seismic events that cause damage to local infrastructure but also offer valuable insight into seismogenesis. The factors that influence the magnitude, location, and number of induced events remain poorly understood but include injection flow rate and pressure as well as reservoir temperature and permeability. The relationship between injection parameters and injection-induced seismicity in high-temperature, high-permeability reservoirs has not been extensively studied. Here we focus on the Ngatamariki geothermal field in the central Taupō Volcanic Zone, New Zealand, where three stimulation/injection tests have occurred since 2012. We present a catalog of seismicity from 2012 to 2015 created using a matched-filter detection technique. We analyze the stress state in the reservoir during the injection tests from first motion-derived focal mechanisms, yielding an average direction of maximum horizontal compressive stress (SHmax) consistent with the regional NE-SW trend. However, there is significant variation in the direction of maximum compressive stress (σ1), which may reflect geological differences between wells. We use the ratio of injection flow rate to overpressure, referred to as injectivity index, as a proxy for near-well permeability and compare changes in injectivity index to spatiotemporal characteristics of seismicity accompanying each test. Observed increases in injectivity index are generally poorly correlated with seismicity, suggesting that the locations of microearthquakes are not coincident with the zone of stimulation (i.e., increased permeability). Our findings augment a growing body of work suggesting that aseismic opening or slip, rather than seismic shear, is the active process driving well stimulation in many environments

The Munich Near-Infrared Cluster Survey (MUNICS) -- II. The K-Band Luminosity Function of Field Galaxies to z ~ 1.2

(Abriged) We present a measurement of the evolution of the rest-frame K-band luminosity function to z ~ 1.2 using a sample of more than 5000 K-selected galaxies drawn from the MUNICS dataset. Distances and absolute K-band magnitudes are derived using photometric redshifts from spectral energy distribution fits to BVRIJK photometry. These are calibrated using >500 spectroscopic redshifts. We obtain redshift estimates having a rms scatter of 0.055 and no mean bias. We use Monte-Carlo simulations to investigate the influence of the errors in distance associated with photometric redshifts on our ability to reconstruct the shape of the luminosity function. Finally, we construct the rest-frame K-band LF in four redshift bins spanning 0.4<z<1.2 and compare our results to the local luminosity function. We discuss and apply two different estimators to derive likely values for the evolution of the number density, Phi*, and characteristic luminosity, M*, with redshift. While the first estimator relies on the value of the luminosity function binned in magnitude and redshift, the second estimator uses the individually measured {M,z} pairs alone. In both cases we obtain a mild decrease in number density by \~ 25% to z=1 accompanied by brightening of the galaxy population by 0.5 to 0.7 mag. These results are fully consistent with an analogous analysis using only the spectroscopic MUNICS sample. The total K-band luminosity density is found to scale as dlog(rho_L)/dz = 0.24. We discuss possible sources of systematic errors and their influence on our parameter estimates.Comment: Accepted for publication in Ap

Analysis of linearized inverse problems in ultrasound transmission imaging

The purpose of this paper is to analyze the linearized inverse problem during the iterativesolution process of the ill-posed nonlinear inverse problem of image reconstruction for ultra-sound transmission imaging. We show that the conjugate gradient applied to normal equation(CGNE) method gives more reliable solutions for linearized systems than Tikhonov regular-ization methods. The linearized systems are more sensitive when treated by CGNE than byTikhonov regularization methods. The Tikhonov regularization is less effective at the be-ginning of the outer-loop iteration, where the nonlinearity is dominating while the conjugategradient for the linearized system stops earlier. Only when the linear approximation is goodenough to describe the whole system, Tikhonov regularization can fully play its role and giveslightly better reconstruction results as compared to CGNE in a very noisy case

Reproducing FSL's fMRI data analysis via Nipype:Relevance, challenges, and solutions

The "replication crisis" in neuroscientific research has led to calls for improving reproducibility. In traditional neuroscience analyses, irreproducibility may occur as a result of issues across various stages of the methodological process. For example, different operating systems, different software packages, and even different versions of the same package can lead to variable results. Nipype, an open-source Python project, integrates different neuroimaging software packages uniformly to improve the reproducibility of neuroimaging analyses. Nipype has the advantage over traditional software packages (e.g., FSL, ANFI, SPM, etc.) by (1) providing comprehensive software development frameworks and usage information, (2) improving computational efficiency, (3) facilitating reproducibility through sufficient details, and (4) easing the steep learning curve. Despite the rich tutorials it has provided, the Nipype community lacks a standard three-level GLM tutorial for FSL. Using the classical Flanker task dataset, we first precisely reproduce a three-level GLM analysis with FSL via Nipype. Next, we point out some undocumented discrepancies between Nipype and FSL functions that led to substantial differences in results. Finally, we provide revised Nipype code in re-executable notebooks that assure result invariability between FSL and Nipype. Our analyses, notebooks, and operating software specifications (e.g., docker build files) are available on the Open Science Framework platform

Superheavy dark matter and ultrahigh energy cosmic rays

The phase of inflationary expansion in the early universe produces superheavy relics in a mass window between 10^{12} GeV and 10^{14} GeV. Decay or annihilation of these superheavy relics can explain the observed ultrahigh energy cosmic rays beyond the Greisen-Zatsepin-Kuzmin cutoff. We emphasize that the pattern of cosmic ray arrival directions with energies beyond 20 EeV will decide between the different proposals for the origin of ultrahigh energy cosmic rays.Comment: Based on an invited talk given by RD at Theory Canada 1, Vancouver, June 2-5, 200

The stellar content of 10 dwarf irregular galaxies

We examine the stellar content of 10 dwarf irregular galaxies of which broad-band CCD photometry was published in Hopp & Schulte-Ladbeck (1995). We also present Halpha images for several of these galaxies. The galaxies in the sample are located outside of the Local Group. Yet, they are still close enough to be resolved into single stars from the ground but only the brightest stars (or star clusters) are detected and there is severe crowding. The sample galaxies were selected to be isolated from massive neighbors; about half of them are (mostly peripheral) members of groups, the other half is located in the field. We discuss the vicinity of the sample galaxies to other dwarf galaxies. In order to interpret single-star photometry and draw conclusions about the stellar content or other distance-dependent quantities, it is crucial that accurate distances to the galaxies be known. The distances to the sample galaxies are not well known since all but one have not had a primary distance indicator measured. We make an attempt to constrain the distances by identifying the envelope of the brightest supergiants in B, B-R and R, B-R color-magnitude diagrams, but the results are not very accurate (we estimate the minimal error on the distance modulus is 1.36 mag). Nevertheless, the fact that the sample galaxies are resolved with direct ground-based imaging indicates that they are sufficiently nearby to represent good candidates for observations with instruments that provide high spatial resolution, e.g., adaptive optics systems on large ground-based telescopes, or the Hubble Space Telescope. ...Comment: 56 pages, 4 tables, 35 figures, The Astronomical Journal, accepte

Immunomodulation in the treatment and/or prevention of bronchial asthma

ABSTRACTThe immunologic hallmark of atopic allergy and asthma is an increased production of IgE and T helper (h) type 2 cell cytokines (interleukin (IL)-4, IL-5, IL-9 and IL-13) by Th cells reacting to common environmental allergens. All of us inhale allergens and healthy non-atopics produce allergen-specific IgG1, IgG4 and the Th1 cytokine interferon-α, as well as IL-12 from macrophages. We now have many modalities of immunomodulation to decrease the effect of IL-4 or IL-5 or production and level of IgE or agents to shift the immune response from a Th2 to a Th1 response, thereby decreasing the allergic inflammatory response in the airways. In the present review we focus on conventional immunotherapy, mycobacterial vaccines, DNA vaccines using cytosine guanosine, inhibitors of IL-4 and IL-5 and anti-IgE: Omalizumab

Properties of M31. II: A Cepheid disk sample derived from the first year of PS1 PAndromeda data

We present a sample of Cepheid variable stars towards M31 based on the first year of regular M31 observations of the PS1 survey in the r_P1 and i_P1 filters. We describe the selection procedure for Cepheid variable stars from the overall variable source sample and develop an automatic classification scheme using Fourier decomposition and the location of the instability strip. We find 1440 fundamental mode (classical \delta) Cep stars, 126 Cepheids in the first overtone mode, and 147 belonging to the Population II types. 296 Cepheids could not be assigned to one of these classes and 354 Cepheids were found in other surveys. These 2009 Cepheids constitute the largest Cepheid sample in M31 known so far and the full catalog is presented in this paper. We briefly describe the properties of our sample in its spatial distribution throughout the M31 galaxy, in its age properties, and we derive an apparent period-luminosity relation (PLR) in our two bands. The Population I Cepheids nicely follow the dust pattern of the M31 disk, whereas the 147 Type II Cepheids are distributed throughout the halo of M31. We outline the time evolution of the star formation in the major ring found previously and find an age gradient. A comparison of our PLR to previous results indicates a curvature term in the PLR