UVMULTIFIT: A versatile tool for fitting astronomical radio interferometric data

The analysis of astronomical interferometric data is often performed on the images obtained after deconvolution of the interferometer's point spread function (PSF). This strategy can be understood (especially for cases of sparse arrays) as fitting models to models, since the deconvolved images are already non-unique model representations of the actual data (i.e., the visibilities). Indeed, the interferometric images may be affected by visibility gridding, weighting schemes (e.g., natural vs. uniform), and the particulars of the (non-linear) deconvolution algorithms. Fitting models to the direct interferometric observables (i.e., the visibilities) is preferable in the cases of simple (analytical) sky intensity distributions. In this paper, we present UVMULTIFIT, a versatile library for fitting visibility data, implemented in a Python-based framework. Our software is currently based on the CASA package, but can be easily adapted to other analysis packages, provided they have a Python API. We have tested the software with synthetic data, as well as with real observations. In some cases (e.g., sources with sizes smaller than the diffraction limit of the interferometer), the results from the fit to the visibilities (e.g., spectra of close by sources) are far superior to the output obtained from the mere analysis of the deconvolved images. UVMULTIFIT is a powerful improvement of existing tasks to extract the maximum amount of information from visibility data, especially in cases close to the sensitivity/resolution limits of interferometric observations.Comment: 10 pages, 4 figures. Accepted in A&A. Code available at http://nordic-alma.se/support/software-tool

Diagnostik von Parasiteninfektionen: Stellenwert der Serologie

Zusammenfassung: Die Attraktivität tropischer und subtropischer Feriendestinationen für europäische Touristen und der anhaltende Zustrom von Immigranten aus solchen Gebieten führen in der ärztlichen Praxis immer öfter zur Differenzialdiagnose einer Parasiteninfektion. Neben den klassischen mikroskopischen Untersuchungen für den Direktnachweis hat die Serologie ihren Stellenwert vor allem beim Nachweis von Gewebeparasiten, in der Präpatenz bis zur Nachweisbarkeit von Vermehrungsprodukten und als Suchtest bei einer Bluteosinophilie nach bekanntem Expositionsrisiko. Der vorliegende Beitrag zeigt mögliche Abklärungsstrategien unter besonderer Berücksichtigung des Stellenwerts der Serologie au

Orbital and Super-Orbital Periods of 1E 1740.7-2942 and GRS 1758-258

Five years of Rossi X-ray Timing Explorer (RXTE) observations of the Galactic black-hole candidates 1E 1740.7-2942 and GRS 1758-258 show a periodic modulation with amplitude 3-4% in each source at 12.73 +/- 0.05 dy and 18.45 +/- 0.10 dy, respectively. We interpret the modulations as orbital, suggesting that the objects have red-giant companions. Combining the RXTE data with earlier data (Zhang, Harmon & Liang 1997) from the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory, we find a long period or quasi-period of about 600 dy in 1E 1740.7-2942, and a suggestion of a similar 600-dy period in GRS 1758-258. These timescales are longer than any yet found for either precessing systems like Her X-1 and SS 433 or binaries like LMC X-3 and Cyg X-1 with more irregular long periods.Comment: 13 pages, 5 figures, accepted by The Astrophysical Journal Letter

Implementasi Aplikasi Monitoring Pengendalian Pintu Gerbang Rumah Menggunakan App Inventor Berbasis Android

Teknologi otomasi semakin hari semakin berkembang begitupula pemanfaatan aplikasi di android tidak lagi hanya sebatas untuk komunikasi chat, sosial media saja. Aplikasi android dapat dimanfaatkan sebagai kendali berbagai peralatan sehari-hari, sehingga dapat mempermudah kegiatan manusia.Pada penelitian ini penulis membuat aplikasi android dengan bantuan app inventor yang dikembangkan oleh Massachusetts Institute of Technology (MIT). Rancangan sistem meliputi hardware dan software. Hardware meliputi mikrokontroler sebagai pusat kendali hardware, driver motor untuk kendali pintu gerbang, modul bluethoot HC-06, rancangan software meliputi aplikasi android yang digunakan untuk membuka pintu gerbang.Hasil perancangan adalah sebuah aplikasi android yang dapat digunakan untuk membuka dan menutup pintu gerbang melalui HP android. Sistem ini memanfaatkan koneksi bluetooth yang terhubung dari android ke sistem mikrokontrole

Diagnostik bei Glomerulonephritis: Rationaler Abklärungsgang

Zusammenfassung: Glomerulonephritiden sind eine wichtige und häufige Ursache der fortgeschrittenen Niereninsuffizienz. Hinsichtlich Therapierbarkeit und Prognose sind eine frühzeitige Abklärung und Diagnosestellung von entscheidender Bedeutsamkeit. Die wichtigsten klinischen Zeichen der Glomerulonephritis per se sind arterielle Hypertonie, Ödeme, Proteinurie, Hämaturie und Niereninsuffizienz. Dazu kommen Symptome allfälliger Systemerkrankungen. Der Abklärungsgang umfasst Erhebung der Anamnese, klinische Untersuchung, Laboruntersuchungen im Blut und Urin, bildgebende Verfahren wie Sonographie und Magnetresonanzuntersuchung und in den meisten Fällen die perkutane Nierenbiopsie. Bei der Diagnostik ist es besonders wichtig, eine behandelbare Ursache - wie Medikamentennebenwirkung, Infekt, Tumor oder entzündliche Systemerkrankung - zu erkennen. Glomerulonephritiden können einerseits aufgrund ihrer klinischen Präsentation und andererseits basierend auf den histologischen Veränderungen genauer klassifiziert werde

Complete-Graph Tensor Network States: A New Fermionic Wave Function Ansatz for Molecules

We present a new class of tensor network states that are specifically designed to capture the electron correlation of a molecule of arbitrary structure. In this ansatz, the electronic wave function is represented by a Complete-Graph Tensor Network (CGTN) ansatz which implements an efficient reduction of the number of variational parameters by breaking down the complexity of the high-dimensional coefficient tensor of a full-configuration-interaction (FCI) wave function. We demonstrate that CGTN states approximate ground states of molecules accurately by comparison of the CGTN and FCI expansion coefficients. The CGTN parametrization is not biased towards any reference configuration in contrast to many standard quantum chemical methods. This feature allows one to obtain accurate relative energies between CGTN states which is central to molecular physics and chemistry. We discuss the implications for quantum chemistry and focus on the spin-state problem. Our CGTN approach is applied to the energy splitting of states of different spin for methylene and the strongly correlated ozone molecule at a transition state structure. The parameters of the tensor network ansatz are variationally optimized by means of a parallel-tempering Monte Carlo algorithm