Towards symmetric scheme for superdense coding between multiparties

Recently Liu, Long, Tong and Li [Phys. Rev. A 65, 022304 (2002)] have proposed a scheme for superdense coding between multiparties. This scheme seems to be highly asymmetric in the sense that only one sender effectively exploits entanglement. We show that this scheme can be modified in order to allow more senders to benefit of the entanglement enhanced information transmission.Comment: 6 page

Optical variability of the ultraluminous X-ray source NGC 1313 X-2

We analyzed the longest phase-connected photometric dataset available for NGC 1313 X-2, looking for the ~6 day modulation reported by Liu et al. (2009). The folded B band light curve shows a 6 days periodicity with a significance slightly larger than 3 sigma. The low statistical significance of this modulation, along with the lack of detection in the V band, make its identification uncertain.Comment: 4 pages, 2 figures. Accepted for publication in the Astronomische Nachrichten (Astronomical Notes), to appear in the proceedings of the conference "Ultra-Luminous X-ray sources and Middle Weight Black Holes" (Madrid, May 24-26, 2010

Breach procedure for axillary hyperhidrosis.

Dear Editor, We read with interest the communication on ‘A simple and practical method for axillary osmidrosis resection’ by Liu X, Mao T, Lei Z, Fan D appeared on JPRAS 2009.1 We found the description of the technique very useful with the support of intra-operative pictures. The use of artery clips to evert the skin flaps can be easily reproduced. However it is surprising that the Authors did not consider and mention in the References a paper by Mr N Breach appeared in the Annals of the Royal College of Surgeons of England in the late 70ies,2 when he was Senior Registrar at the Plastic Surgery Department of the Queen Victoria Hospital, East Grinstead, UK. Since then this latter procedure for surgical treatment of axillary hyperhidrosis has been widely adopted, [3], [4] and [5] especially in the Western world and in the UK where is known as the ‘Breach’ procedure. The main difference with the technique described in the paper by Liu X et al. consists in the number of incisions that has now been minimized

On the qq-log-convexity conjecture of Sun

In his study of Ramanujan-Sato type series for $1/\pi$, Sun introduced a sequence of polynomials $S_n(q)$ as given by $$S_n(q)=\sum\limits_{k=0}^n{n\choose k}{2k\choose k}{2(n-k)\choose n-k}q^k,$$ and he conjectured that the polynomials $S_n(q)$ are $q$-log-convex. By imitating a result of Liu and Wang on generating new $q$-log-convex sequences of polynomials from old ones, we obtain a sufficient condition for determining the $q$-log-convexity of self-reciprocal polynomials. Based on this criterion, we then give an affirmative answer to Sun's conjecture

Ownership structure and new product development in transnational corporations in China

This article is available open access through the publisher’s website at the link below. Copyright @ 2008 United Nations.This paper examines the relationship between the ownership structure and new product development (NPD) at the affiliates of transnational corporations in China. Seven research hypotheses are tested on a panel data set covering 10,000 manufacturing firms with foreign involvement for the period 1998-2001. The results from probit and tobit models show that contractual joint ventures, equity joint ventures and joint stock enterprises are better organizational forms than wholly owned enterprises for increasing both the probability and intensity of NPD. We also find that ventures with OECD participation are more likely to be involved in NPD than those with participation by “overseas” Chinese TNCs