The optimal number of contracts in cross- or delta-hedges.

When hedging in futures markets, the hedge instruments typically fail to match the exposed asset or portfolio by expiration date and/or underlying asset. The theoretical variance-minimizing hedge is given by the slope coefficient of the conditional (forward-looking) regression of the spot-price that one is exposed to on the futures price used as a hedge. We explore the hedging performance of simple rules of thumb and of unconditional regressions on past data, focusing on the effect of the choice of observation frequency, sample period, percentage vs. dollar returns, and lead/lag effects. Our findings are the following : (a) the effects of varying the observation frequency, sample period, etc., are much larger than the effects of using GARCH instead of OLS. (b) Regardless of sample size and estimation technique, the exposure is best estimated using percentage returns rather than (dollar) first differences. © In the case of delta hedges, and also a cross-hedges among closely related currencies, regressions are systematically beaten by naïve rules of thumb. (d) This relatively poor performance of regression-based hedges is not just due to errors in data. (e) The optimal estimation technique depends on the situation. For cross-hedges involving two European currencies, high-frequency OLS estimates is flawed by EMS-induced leads and lags among exchange rate changes, and the best regressions are those using monthly data from longish sample periods. For delta-hedges the dominant source of estimation problems seems to be a time-varying relationship between the regression variables, and the best regressions use daily data from short sample periods.Optimal;

The information content in bond model residuals: an empirical study on the Belgian bond market.

We estimate daily Vasicek, CIR, and spline models on Belgian data and compare the trading profits that can be made on the basis of the model residuals. Abnormal returns are negatively related to lagged mispricing. Contrarian strategies - buying underpriced bonds, and especially selling overpriced bonds- yield significant abnormal returns even when the trade is delaved by up to five days after observing the mispricing. The sline model seems to overfit the data and is least able to detect mispricing. Large model residuals are more likely to be the result of model misspecification or -estimation than are small or medium-sized residuals.Model; Residuals; Studies;

Japan's Corporate returns on value and cost: a comprehensive look.

The paper documents that for 1974-95 the Japanese non-financials' return on cost, a measure of return on (direct) investment, is consistently higher than their return on value (an estimate of the expected return or cost of capital). Against conventional wisdom, when translated into USD terms, the Japanese cost of capital is actually higher than the U.S. counterpart. The paper further shows that as of the 90s the main-bank centered keirestu firms, with their internally disciplined corporate governance system, lost their traditional advantage of lower cost of capital, compared to the non-keiretsu firms. Examining corporate earnings, investment, and forms of financing reveals that, in recent years, keiretsu firms have become more liquidity constrained than non-keiretsu firms. Their investment drops dramatically, and while (also much reduced) retained cash earnings provide most of the financing, debt financing is replaced by more expensive new equity as the major source of outside financing. Non-keiretsu firms are suffering as well, but to a lesser degree, and are still able to finance their investment even with substantial short-term debts. The main-bank system seems starting to crumble following an over-investment episode in late-80s.Value;

Reexamining the relation between debt mix and growth in Japan.

We propose a U-shaped relation between the relative weight of bank loans in total corporate debt and the firm's market-to-book ratio-a proxy for expected growth-which reconciles most existing theories. Using data on Japanese firms for 1983-97, we do find that, in the lower range of growth spectrum, firms with better prospects take more bonds in their debt mix: when the firm's prospects improve, the benefits from private debt initially fall relative to its costs. In contrast, in the higher range of growth, firms with more growth potentials take more monitored debt, reflecting, amongst other factors, the higher information and contracting costs of public debt faced by extreme growers. We can explain the seemingly conflicting evidence that Anderson and Makhija (1999) and Hoshi, Kashyap and Scharfstein (1993) provide in this respect. We also find that keiretsu firms do not behave significantly different from non-keiretsu ones, suggesting that keiretsu firms are fairly independent in their financing decisions and that extra costs and benefits from bank loans are either small or in reasonable balance. Firms that faced restrictions in issuing bonds, pre-1990, continue to behave differently from other firms long after the restrictions were lifted.

A natural product-like JAK2/STAT3 inhibitor induces apoptosis of malignant melanoma cells

The JAK2/STAT3 signaling pathway plays a critical role in tumorigenesis, and has been suggested as a potential molecular target for anti-melanoma therapeutics. However, few JAK2 inhibitors were being tested for melanoma therapy. In this study, eight amentoflavone analogues were evaluated for their activity against human malignant melanoma cells. The most potent analogue, compound 1, inhibited the phosphorylation of JAK2 and STAT3 in human melanoma cells, but had no discernible effect on total JAK2 and STAT3 levels. A cellular thermal shift assay was performed to identify that JAK2 is engaged by 1 in cell lysates. Moreover, compound 1 showed higher antiproliferative activity against human melanoma A375 cells compared to a panel of cancer and normal cell lines. Compound 1 also activated caspase-3 and cleaved PARP, which are markers of apoptosis, and suppressed the anti-apoptotic Bcl-2 level. Finally, compound 1 induced apoptosis in 80% of treated melanoma cells. To our knowledge, compound 1 is the first amentoflavone-based JAK2 inhibitor to be investigated for use as an anti-melanoma agent.published_or_final_versio

Gene and protein expression of glucose transporter 1 and glucose transporter 3 in human laryngeal cancer—the relationship with regulatory hypoxia-inducible factor-1α expression, tumor invasiveness, and patient prognosis

Increased glucose uptake mediated by glucose transporters and reliance on glycolysis are common features of malignant cells. Hypoxia-inducible factor-1α supports the adaptation of hypoxic cells by inducing genes related to glucose metabolism. The contribution of glucose transporter (GLUT) and hypoxia-inducible factor-1α (HIF-1α) activity to tumor behavior and their prognostic value in head and neck cancers remains unclear. The aim of this study was to examine the predictive value of GLUT1, GLUT3, and HIF-1α messenger RNA (mRNA)/protein expression as markers of tumor aggressiveness and prognosis in laryngeal cancer. The level of hypoxia/metabolic marker genes was determined in 106 squamous cell laryngeal cancer (SCC) and 73 noncancerous matched mucosa (NCM) controls using quantitative realtime PCR. The related protein levels were analyzed by Western blot. Positive expression of SLC2A1, SLC2A3, and HIF-1α genes was noted in 83.9, 82.1, and 71.7 % of SCC specimens and in 34.4, 59.4, and 62.5 % of laryngeal cancer samples. Higher levels of mRNA/protein for GLUT1 and HIF-1α were noted in SCC compared to NCM (p<0.05). SLC2A1 was found to have a positive relationship with grade, tumor front grading (TFG) score, and depth and mode of invasion (p<0.05). SLC2A3 was related to grade and invasion type (p<0.05). There were also relationships of HIF-1α with pTNM, TFG scale, invasion depth and mode, tumor recurrences, and overall survival (p<0.05). In addition, more advanced tumors were found to be more likely to demonstrate positive expression of these proteins. In conclusion, the hypoxia/metabolic markers studied could be used as molecular markers of tumor invasiveness in laryngeal cancer.This work was supported, in part, by the statutory fund of the Department of Cytobiochemistry, University of Łódź, Poland (506/811), and by grant fromtheNational Science Council, Poland (N403 043 32/2326)

Very Cold Gas and Dark Matter

We have recently proposed a new candidate for baryonic dark matter: very cold molecular gas, in near-isothermal equilibrium with the cosmic background radiation at 2.73 K. The cold gas, of quasi-primordial abundances, is condensed in a fractal structure, resembling the hierarchical structure of the detected interstellar medium. We present some perspectives of detecting this very cold gas, either directly or indirectly. The H$_2$ molecule has an "ultrafine" structure, due to the interaction between the rotation-induced magnetic moment and the nuclear spins. But the lines fall in the km domain, and are very weak. The best opportunity might be the UV absorption of H$_2$ in front of quasars. The unexpected cold dust component, revealed by the COBE/FIRAS submillimetric results, could also be due to this very cold H$_2$ gas, through collision-induced radiation, or solid H$_2$ grains or snowflakes. The $\gamma$-ray distribution, much more radially extended than the supernovae at the origin of cosmic rays acceleration, also points towards and extended gas distribution.Comment: 16 pages, Latex pages, crckapb macro, 3 postscript figures, uuencoded compressed tar file. To be published in the proceeedings of the "Dust-Morphology" conference, Johannesburg, 22-26 January, 1996, D. Block (ed.), (Kluwer Dordrecht

The Galactic Halo from Microlensing

The status of the microlensing search for galactic dark matter in the form of massive astronomical compact halo objects (machos) is reviewed. Unresolved issues are discussed, as well as possible ways to solve these

Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.

BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal