Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Der naturwissenschaftliche Sachunterricht in Lehrplänen, Unterrichtsmaterialien und Schulpraxis - Eine quantitative Analyse der Entwicklung in den letzten 25 Jahren

Strunk U, Lück G, Demuth R. Der naturwissenschaftliche Sachunterricht in Lehrplänen, Unterrichtsmaterialien und Schulpraxis - Eine quantitative Analyse der Entwicklung in den letzten 25 Jahren. Zeitschrift für Didaktik der Naturwissenschaften : ZfDN ; Biologie, Chemie, Physik. 1998;4(1):69-80

Taxation of E-Commerce: Persistent Problems and Recent Developments

E-commerce on the Internet will create new demands on taxation. In the field of income and business taxation there exists a large potential for profit-shifting into low-tax countries, especially concerning transfers of immaterial goods and transfer pricing. In the long run, this can lead to a severe revenue shortfall. Turnover taxation/VAT raise problems if foreign suppliers sell electronic products or services to final consumers online. VAT should be charged in the country where the consumption takes place, which is currently not the case. Otherwise, distortions of competition and unjust effects of taxation will become more comprehensive. This requires special technical solutions and closer international co-operation among taxation authorities. As a basic principle, e-commerce should not enjoy tax privileges. Rather, it should compete against the traditional economy on the basis of its specific advantages, which, on the other hand, should not be impeded by undue taxation procedures. Zusammenfassung Besteuerung des E-Commerce: Anhaltende Probleme und neuere Entwicklungen E-Commerce über das Internet bedeutet neue Herausforderungen für die Besteuerung. Im Bereich der Einkommens- und Unternehmensbesteuerung entsteht ein großes Potential zur Verlagerung von Einkünften in Niedrigsteuerländer, insbesondere durch Gestaltung von Verrechnungspreisen und durch Übertragung von immateriellen Wirtschaftsgütern. Längerfristig sind dadurch erhebliche Steuerausfälle zu befürchten. Bei der Umsatzsteuer (Mehrwertsteuer) entstehen Probleme, wenn ausländische Anbieter an inländische Endverbraucher elektronische Produkte oder Dienstleistungen online verkaufen. Die Mehrwertsteuer sollte in dem Land erhoben werden, wo der Verbrauch stattfindet, was gegenwärtig nicht der Fall ist, andernfalls drohen Wettbewerbsverfälschungen und ungerechte Steuerbelastungen. Dies erfordert besondere technische Lösungen sowie eine verstärkte internationale Kooperation der Finanzbehörden. Grundsätzlich sollte der e-commerce nicht steuerlich privilegiert werden, sondern sich aufgrund seiner spezifischen Wettbewerbsvorteile durchsetzen, andererseits sollte er aber auch nicht durch aufwendige steuertechnische Anforderungen behindert werden

Renal failure after high-dose methotrexate in a child homozygous for MTHFR C677T polymorphism

We report the case of an 11-year-old female treated for mediastinal T-cell lymphoma who presented renal failure following the second cycle of high-dose methotrexate (HDMTX). Because of life threatening plasma methotrexate (MTX) levels, carboxypeptidase G2 (CPDG2) was administered resulting in a dramatic decrease within 1 hr. The patient recovered from renal failure and no other side effects were observed. Homozygosity for the methylentetrahydrofolate reductase (MTHFR) C677T polymorphism diagnosed by molecular genetic analysis was the only explanation for this toxicity

Soluble TNF-Alpha-Receptors I Are Prognostic Markers in TIPS-Treated Patients with Cirrhosis and Portal Hypertension

BACKGROUND: TNFα levels are increased in liver cirrhosis even in the absence of infection, most likely owing to a continuous endotoxin influx into the portal blood. Soluble TNFα receptors (sTNFR type I and II) reflect release of the short-lived TNFα, because they are cleaved from the cells after binding of TNFα. The aims were to investigate the circulating levels of soluble TNFR-I and -II in cirrhotic patients receiving TIPS. METHODS: Forty-nine patients with liver cirrhosis and portal hypertension (12 viral, 37 alcoholic) received TIPS for prevention of re-bleeding (n = 14), therapy-refractory ascites (n = 20), or both (n = 15). Portal and hepatic venous blood was drawn in these patients during the TIPS procedure and during the control catheterization two weeks later. sTNFR-I and sTNFR-II were measured by ELISA, correlated to clinical and biochemical characteristics. RESULTS: Before TIPS insertion, sTNFR-II levels were lower in portal venous blood than in the hepatic venous blood, as well as in portal venous blood after TIPS insertion. No significant differences were measured in sTNFR-I levels. Hepatic venous levels of sTNFR-I above 4.5 ng/mL (p = 0.036) and sTNFR-II above 7 ng/mL (p = 0.05) after TIPS insertion were associated with decreased survival. A multivariate Cox-regression survival analysis identified the hepatic venous levels of sTNFR-I (p = 0.004) two weeks after TIPS, and Child score (p = 0.002) as independent predictors of mortality, while MELD-score was not. CONCLUSION: Hepatic venous levels of sTNFR-I after TIPS insertion may predict mortality in patients with severe portal hypertension