delta(13)C values of the lichens Ramalina duriaei and Teloschistes villosus collected in their natural habitat were repeatedly measured during 2 years. Results show variations in the stable carbon isotope ratios ((13)C/(12)C). Such variations are correlated to the seasonal rainfall, i.e. low values of delta(13)C of the lichens during the winter and high values of delta(13)C during the dry summe...

Repeated exercise tests demonstrate refractoriness to the development of exercise-induced asthma (EIA). It is unclear whether it is the initial exercise per se or the resulting bronchoconstriction that causes the attenuated response to the second exercise challenge. This study was designed to determine whether the reported blocking of the refractory period by indomethacin requires a significant...

BACKGROUND AND AIMS Mimetic seeds simulate the appearance of fleshy fruits and arilled seeds without producing nutritive tissues as a reward for seed dispersers. In this strategy of seed dispersal, seeds may remain attached to the mother plant for long periods after maturity, increasing their availability to naïve seed dispersers. The hypothesis that seed coat impermeability in many tropical Fa...

Tanzania 2002 Summary The continued vicious cycle of population-poverty-and-environmental degradation has been acknowledged. The purpose of this paper, therefore, is to draw attention to the serious consequences of land degradation, a national and trans-national socioeconomic complex problem, and the need for rehabilitating degraded lands in the sub-humid lands of Sub-Saharan Africa (SSA). The ...

To investigate the effect of aging at 580 °C in wet air (humid aging) on the oxygen adsorption on the surface of SnO₂ particles, the electric properties and the sensor response to hydrogen in dry and humid atmospheres for SnO₂ resistive-type gas sensors were evaluated. The electric resistance in dry and wet atmospheres at 350 °C was strongly increased by humid aging. From the results of oxygen ...

Using observed daily temperatures in China, three independent types of heat waves (HWs), including daytime HWs, nighttime HWs, and compound HWs (with both extreme daily maxima and minima), were defined. Different types of HWs showed distinctive preferences in occurrence locations and timing. However, spatial patterns of accompanying relative humidity were generally independent of categorization...

Desiccation tolerance was quantified in four cyanolichens (Lobaria hallii, Lobaria retigera, Lobaria scrobiculata, Pseudocyphellaria anomala), one cephalolichen (Lobaria pulmonaria) and one chlorolichen (Platismatia glauca) from xeric and mesic, open and closed North American boreal forests. These sympatric epiphytes were exposed to 0%, 33%, 55% and 75% relative humidity with or without medium ...

Flood simulation and forecasting in various types of watersheds is a hot issue in hydrology. Conceptual hydrological models have been widely applied to flood forecasting for decades. With the development of economy, modern China faces with severe flood disasters in all types of watersheds include humid, semi-humid semi-arid and arid watersheds. However, conceptual model-based flood forecasting ...