Gravity models are widely used to explain patterns of trade. However, two stylized features of trade data, sample selection and heteroskedasticity, challenge the estimation of gravity models. We propose a Two-Step Method of Moments (TS-MM) estimator that deals with both issues. The Monte-Carlo experiments show that the TS-MM estimates are resistant to various combinations of sample selection an...

We present optical photometry of the low mass X-ray binary systems GX 349+2 (=X1702-363) and Ser X-1 (=X1837+049). Extensive V RI photometry of the faint optical counterpart (V = 18.4) to GX 349+2 reveals a period of 22.5 ± 0.1 h and halfamplitude 0.2 mag. This result confirms and extends our previously reported 22 h period (Wachter & Margon 1996). No color change is detected over the orbit, al...

The objective of the present study was to investigate whether pretreatment with single low loading dose of tongxinluo (TXL), a traditional Chinese medicine, 1 h before myocardial ischemia could attenuate no-reflow and ischemia-reperfusion injury by regulating endothelial nitric oxide synthase (eNOS) via the PKA pathway. In a 90-min ischemia and 3-h reperfusion model, minipigs were randomly assi...

Background: Mycobacterial infection is a problem throughout the world along with the increase of immunocompromised patients. For this reason, there have been many methods for faster and more accurate diagnosis. In this study, we evaluated several laboratory methods for mycobacterial infection. Methods: From January to December 2009, 635 specimens were cultured with mycobacteria growth indicator...

References http://rstb.royalsocietypublishing.org/content/363/1491/611.full.html#ref-list-1 This article cites 42 articles, 8 of which can be accessed free Rapid response http://rstb.royalsocietypublishing.org/letters/submit/royptb;363/1491/611 Respond to this article Email alerting service here right-hand corner of the article or click Receive free email alerts when new articles cite this arti...

References http://rstb.royalsocietypublishing.org/content/363/1491/467.full.html#ref-list-1 This article cites 7 articles, 2 of which can be accessed free Rapid response http://rstb.royalsocietypublishing.org/letters/submit/royptb;363/1491/467 Respond to this article Email alerting service here right-hand corner of the article or click Receive free email alerts when new articles cite this artic...

We examined the influence of individual serine phosphorylation sites in endothelial nitric-oxide synthase (eNOS) on basal and stimulated NO release, cooperative phosphorylation, and co-association with hsp90 and Akt. Mutation of the serine phosphorylation sites 116, 617, and 1179 to alanines affected the phospho-state of at least one other site, demonstrating cooperation between multiple phosph...

Inorganic nanoprobes with ultrasmall size have the advantage of kidney clearance, which was very meaningful for achieving clinical application. In this article, Mn2+-doped gold nanoclusters (Mn-AuNCs) were synthesized, by magnetic resonance imaging (MRI) and tumor-microenvironment-responsive chemodynamic therapy (CDT) photodynamic (PDT) achieved. The results showed that...