The mossflora of Xishuangbanna, Southern Yunnan, China

This is the first contribution on the moss flora of Xishuangbanna, southern Yunnan Province, one of the main tropical areas in China. This rich moss flora shows a similarity to that of Southeast Asia and the Himalayas

Taking Positive Interest Rates Seriously

We present a dynamic term structure model in which interest rates of all maturities are bounded from below at zero. Positivity and continuity, combined with no arbitrage, result in only one functional form for the term structure with three sources of risk. One dynamic factor controls the level of the interest rate and follows a special two-parameter square-root process under the risk-neutral measure. The two parameters of the process determine the other two sources of risk and act as two static factors. This model has no other parameters to estimate and hence bears no other risks.Term structure, consistency, positivity, quadratic forms