The long-term ecological response to recurrent deforestation associated with shifting cultivation remains poorly investigated, especially in the dry tropics. We present a study of phosphorus (P) dynamics in the southern Yucatán, highlighting the possibility of abrupt shifts in biogeochemical cycling resulting from positive feedbacks between vegetation and its limiting resources. After three cul...

With the advent of sophisticated networking technologies and the related applications, more and more computers are getting hooked to the Internet. This is mainly for utilizing several services ranging from information sharing to electronic transactions. P2P networks which allow decentralized systems, have posed problems related to trust when transactions have to be carried out. Current literatu...

Through perceptual experiments, the fundamental frequency (F0) in mora unit was defined which well corresponded to the perceived pitch value. Several candidates, given as the combination of periods of observation and methods of F0 calculation, were tested. Based on the definition, a method was developed for the accurate recognition of Japanese lexical accents, and was applied to a system for te...

Submitted for the MAR06 Meeting of The American Physical Society Compact Dynamical Equations for Brain Activity JONG WON KIM, PETER A. ROBINSON, School of Physics, University of Sydney, Australia. Brain Dynamics Center, Westmead Hospital and University of Sydney, Australia — A continuum model of brain dynamics has recently been developed to reproduce and unify many features of electroencephalog...

Indian monsoon rainfall is vital for a large share of the world’s population. Both reliably projecting India’s future precipitation and unraveling abrupt cessations of monsoon rainfall found in paleorecords require improved understanding of its stability properties. While details of monsoon circulations and the associated rainfall are complex, full-season failure is dominated by large-scale pos...

During bouncing gaits (running, hopping, trotting), passive compliant structures (e.g. tendons, ligaments) store and release part of the stride energy. Here, active muscles must provide the required force to withstand the developing tendon strain and to compensate for the inevitable energy losses. This requires an appropriate control of muscle activation. In this study, for hopping, the potenti...

Of all recurring natural disasters, long-term drought is one of the most devastating and costly due to large spatial extent and often long duration. The mechanisms responsible for the maintenance of long-term droughts are not well understood, however many drought analyses allege the importance of land-atmosphere feedbacks and speculate that these feedbacks will amplify changes in the hydrologic...

To realistically simulate climate feedbacks from the land surface to the atmosphere, models must replicate the responses of plants to environmental changes. Several processes, operating at various scales, cause the responses of photosynthesis and plant respiration to temperature and CO2 to change over time of exposure to new or changing environmental conditions. Here, we review the latest empir...

Wildfire size, frequency, and severity are increasing in the Alaskan boreal forest in response to climate warming. One of the potential impacts of this changing fire regime is the alteration of successional trajectories, from black spruce to mixed stands dominated by aspen, a vegetation composition not experienced since the early Holocene. Such changes in vegetation composition may consequently...

Boreal forests store a large fraction of global terrestrial carbon and are susceptible to environmental change, particularly rising temperatures and increased fire frequency. These changes have the potential to drive positive feedbacks between climate warming and the boreal carbon cycle. Because few studies have examined the warming response of boreal ecosystems recovering from fire, we establi...