Central rotations of Milky Way Globular Clusters

Most Milky Way globular clusters (GCs) exhibit measurable flattening, even if on a very low level. Both cluster rotation and tidal fields are thought to cause this flattening. Nevertheless, rotation has only been confirmed in a handful of GCs, based mostly on individual radial velocities at large radii. We are conducting a survey of the central kinematics of Galactic GCs using the new Integral Field Unit instrument VIRUS-W. We detect rotation in all 11 GCs that we have observed so far, rendering it likely that a large majority of the Milky Way GCs rotate. We use published catalogs of the ACS survey of GCs to derive central ellipticities and position angles. We show that in all cases where the central ellipticity permits an accurate measurement of the position angle, those angles are in excellent agreement with the kinematic position angles that we derive from the VIRUS-W velocity fields. We find an unexpected tight correlation between central rotation and outer ellipticity, indicating that rotation drives flattening for the objects in our sample. We also find a tight correlation between central rotation and published values for the central velocity dispersion, most likely due to rotation impacting the old dispersion measurements.Comment: 6 pages, 3 figures; accepted for publication in ApJ Letter

Mt. Wendelstein imaging of comet 41P/Tuttle-Giacobini-Kresak during the 2017 perihelion arc

Comet 41P/Tuttle-Giacobini-Kresak (41P), a Jupiter family comet with three discoveries over about 100 years, is in a short-periodic orbit around the Sun with the perihelion close to the Earth distance. The 2017 apparition of 41P offered a long-lasting visibility of the comet at a close distance to Earth. The four month-long imaging campaign with the 2 m telescope at the Mount Wendelstein Observatory was aimed at characterizing dust activity and nucleus properties of the comet. Using a new analysis method of the inner coma flux, we derived a small mean equivalent radius of about 600 m for the nucleus with an unusual body axes ratio that is higher than two. The nucleus rotation axis was determined from the geometric appearance of coma structures, which were enhanced in the images. A long-lasting coma fan was produced by an extended region at high latitudes on the slowly rotating nucleus, whereas isolated jets originated from narrow, low latitude active regions on the nucleus. The dust activity of 41P, despite being difficult to quantify exactly because of an unknown phase function correction for the comet, indicates a steep radial profile that falls off with an increasing distance from the Sun. Colors and flux profiles provide evidence for dust fragmentation in the inner coma of the comet. A singular outburst event created various dust structures in the coma. The outburst came from an extended region on the nucleus and was due to either a landslide on the nucleus or a sudden material release from a subsurface pocket of volatile ice.Comment: Published on 29 May 2020 in A&A, 25 pages, 12 figures, 9 table

Seminar-Beiträge Cache-Optimierung

Dieser Bericht enthält die Ausarbeitungen von Vorträgen aus einem Seminar gleichen Namens, das am 29. Januar 1998 am Institut für Programmstrukturen und Datenorganisation unter Leitung von Holger Hopp, Daniela Genius und Michael Philippsen stattfand. Die Ausarbeitungen geben einen Überblick über Techniken und Modelle, um die Zwischenspeicher (Caches), die in praktisch allen heutigen Rechnern eingesetzt werden, effektiv einzusetzen. Dabei stehen insbesondere solche Techniken im Vordergrund, die von Übersetzern ausgeführt werden können wie diverse Schleifentransformationen, Speicherabbildungen, Vorzeitiges Laden von Daten. Außerdem werden Konsistenzmodelle für Parallelrechner untersucht

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

Factors associated with the decision to obtain an HIV test among Chinese/Chinese American community college women in Northern California

HIV testing and counseling is the cornerstone of a comprehensive approach to HIV prevention and education. This article examines reasons for and barriers to obtaining an HIV test among 230 Chinese/Chinese American college students. Using Health Belief Model constructs, a cross-sectional study was administered at four California community college campuses. The self-report survey results indicated that 30% of respondents have obtained HIV testing. The most common reasons for testing were “just to find out” (73%), “having had unprotected sexual intercourse” (63%), and “having had sex with a new partner” (57%). Among those who were never tested, low levels of perceived susceptibility (66%) and lack of knowledge on testing sites (36%) were the most common barriers. Multiple unconditional logistic regression analyses revealed age, ethnic identity, lack of condom use during last intercourse, lower perceived barriers, and higher self-efficacy as significant predictors of HIV testing history. Emphasizing these factors in HIV education campaigns will likely increase testing rates within this population

Recombinant human preproinsulin expression, purification and reaction with insulin autoantibodies in sera from patients with insulin-dependent diabetes mellitus

A novel prokaryotic expression vector pGEX-6T was designed for high-level expression of recombinant fusion protein with a histidine-hexapeptide and glutathione-S-transferase at its N-terminus and the recombinant human preproinsulin at its C-terminus. Efficiency of expression was investigated in the Escherichia coli strain CAG456. The synthesized protein was sequestered in an insoluble form in inclusion bodies and was purified to homogeneity by one-step affinity chromatography based on the specific complex formation of the histidine-hexapeptide and a chelating matrix which was charged with Ni2+ ions. The antigenic nature of the purified recombinant preproinsulin fusion protein was evaluated by ELISA screening for insulin autoantibodies in selected sera from patients with recent-onset type 1 (insulin-dependent) diabetes mellitus classified by the existence of additional autoantibodies reactive against glutamic acid decarboxylase. 14% of the tested sera (n=43) conttained insulin autoantibodies which strongly recognized the recombinant human preproinsulin. Comparable measurements with both recombinant human preproinsulin and mature insulin suggested that the observed autoantigenicity of preproinsulin was mediated by the C-peptide or/and signal peptide

Fast reflectivity imaging in 3D using SAFT

The computational burden for 3D Synthetic Aperture Focusing Technique (SAFT) is large as for each voxel the delay for each acquired A-scan has to be calculated, e.g. O(N5) for N3 voxels and N2 A-scans. For 3D reconstruction of objects which are large in terms of the wavelength, e.g. ≥ (100 )³, the computation of one volume takes several days on a current multicore PC. If the 3D distribution of speed of sound is applied to correct the delays for objects with varying speed of sound the computation time increases further. This overview paper presents the implementations for 3D SAFT developed by the KIT group and discusses their computational performance