This paper deals with many valued case of modus ponens. Cases with implicative and with clausal rules are studied. Many valued modus ponens via discrete connectives is studied with implicative rules as well as with clausal rules. Some properties of discrete modus ponens operator are given.
Water scarcity poses a major threat to food security and human health in Central America and is increasingly recognized as a pressing regional issues caused primarily by deforestation and population pressure. Tools that can reliably simulate the major components of the water balance with the limited data available and needed to drive management decision and protect water supplies in this region. Four adjacent forested headwater catchments in La Tigra National Park, Honduras, ranging in size from 70 to 635 ha were instrumented and discharge measured over a one year period. A semi-distributed water balance model was developed to characterize the bio-hydrology of the four catchments, one of which is primarily cloud forest cover. The water balance model simulated daily stream discharges well, with Nash Sutcliffe model efficiency (E) values ranging from 0.67 to 0.90. Analysis of calibrated model parameters showed that despite all watersheds having similar geologic substrata, the bio-hydrological response the cloud forest indicated less plantavailable water in the root zone and greater groundwater recharge than the non cloud forest cover catchments. This resulted in watershed discharge on a per area basis four times greater from the cloud forest than the other watersheds despite only relatively minor differences in annual rainfall. These results highlight the importance of biological factors (cloud forests in this case) for sustained provision of clean, potable water, and the need to protect the cloud forest areas from destruction, particularly in the populated areas of Central America.
Significant linear relationships between photosynthetic capacity and principal components loaded by phloem cell numbers and tracheary elements per minor vein as well as the latter two normalized for vein density (proxy for apoplastic phloem loading capacity involving membrane transporters) were revealed for all apoplastic loaders (summer annuals and winter annual Arabidopsis thaliana). In addition, significant linear relationships between photosynthetic capacity and a principal component loaded by tracheary element cross-sectional areas and volumes per unit of leaf area (water flux capacity proxy) was present for symplastic and apoplastic loaders. Lastly, a significant linear relationship between photosynthetic capacity and a principal component loaded by phloem cell cross-sectional areas and volumes per unit of leaf area (proxy for symplastic loading capacity involving cytosolic enzymes for companion cells) was revealed for summer annual symplastic loaders as well as for A. thaliana (in the case of sieve elements, a proxy for sugar export capacity from the leaves)., S. K. Polutchko, J. J. Stewart, B. Demmig-Adams, W. W. Adams., and Obsahuje bibliografické odkazy
Superoxide dismutase (SOD) activity and parameters of chlorophyll fluorescence, the ratio of maximal to variable fluorescence (Fv/Fm), maximal fluorescence (Fm), and minimal fluorescence (F0) were determined on Picea abies growing at different altitudes. The decreases of Fv/Fm and Fm, in comparison to samples from the lower stands (control), were found on trees from the highest stands. The decrease of fluorescence parameters was reversible, at least partly, after keeping branches for some days in the laboratory. Fv/Fm measured in spring when trees were partially covered with snow revealed greater degree of photoinactivation in branches collected from above the snow in comparison to those from below the snow. In samples collected from above snow also slower recovery from stress was observed. Two main SOD isoforms were determined in needles of P. abies, and classified as CuZnSODs. The activity of both SOD isoforms was increasing with the altitude, thus indicating the highest level of oxidative stress at the timberline zone. and Z. Miszalski ... [et al.].
Employing evapotranspiration models is a widely used method to estimate reference evapotranspiration (ETREF) based on weather data. Evaluating such models considering site-specific boundary conditions is recommended to interpret ETREF-calculations in a realistic and substantiated manner. Therefore, we evaluated the ASCE standardized ETREF-equations at a subhumid site in northeastern Austria. We calculated ETREF-values for hourly and daily time steps, whereof the former were processed to sum-of-hourly values. The obtained data were compared to each other and to ETvalues measured by a weighing lysimeter under reference conditions. The resulting datasets covered daily data of the years 2004 to 2011. Sum-of-hourly values correlated well (r2 = 0.978) with daily values, but an RMSE of 0.27 mm specified the differences between the calculation procedures. Comparing the calculations to lysimeter measurements revealed overestimation of small ETREF-values and underestimation of large values. The sum-of-hourly values outperformed the daily values, as r2 of the former was slightly larger and RMSE was slightly smaller. Hence, sum-of-hourly computations delivered the best estimation of ETREF for a single day. Seasonal effects were obvious, with computations and measurements being closest to each other in the summer months.