Effect of Temperature on Texture of Corn Tortilla With and Without Antistaling Agents

Tortilla stiffening should occur between ‐23 to 57°C, showing a maximum rate near the midpoint of this range (17°C). Starch recrystallization below the glass transition temperature (T_g = ‐23°C) in corn tortillas is minimal due to lack of molecular mobility. The objective of this study was to determine the effect of storage temperature (‐20 to 21°C) on the stiffening rate of corn tortillas with or without additives (carboxy‐methylcellulose [CMC] and maltogenic amylase). Tortilla pliability, stiffness, and energy dissipated obtained by stress relaxation, and amylopectin recrystallization determined by differential scanning calorimetry (DSC) showed a second‐order polynomial relationship with temperature. Tortillas became stiff faster during refrigerated storage (3–10°C). Adding 0.25% CMC and 1,650 AU of amylase maintained tortilla softness and flexibility, both at room temperature and under refrigeration for at least three weeks.     

Does Land Use Planning Slow the Conversion of Forest and FarmLands?

Land use planning often is implemented to control development on forests and farmland, but its impact on land use remains untested. Previous studies evaluating such programs have relied on anecdotal evidence rather than on data describing actual land use change. A model of land use is specified as a function of socioeconomic factors, land rent, and landowners' characteristics, to examine how well Oregon's land use planning program has protected forests and farmland from development. The empirical model describes the probability that forests and farmland in western Oregon and western Washington were developed to residential, commercial, or industrial uses, before and after Oregon's land use planning program took effect. Land use data are provided by the USDA Forest Service's Forest Inventory and Analysis program. Results suggest that Oregon's land use planning program has concentrated development within urban growth boundaries since its implementation, but its success at reducing the likelihood of development on resource lands located within forest use and exclusive farm use zones remains uncertain.     

Novel lysimeter techniques — a basis for the improved investigation of water,gas, and solute transport in soils

For many years lysimeters have been proven to be effective tools in assessing and predicting the effects of current land use and future land use changes in catchment areas on both water and solute balances. Although due to the diverse aspects of mass transport modelling, many different types of lysimeters exist, water and solute balances are by no means fully understood, especially in post‐mining areas. To tackle this problem, a new piece of equipment has been developed which enables the actual weight of a lysimeter to be precisely measured. The newly designed device, which has been used for one of the experiments described in this paper, permits the weighing of for example a 2 m³ lysimeter vessel with an accuracy down to 30 g. The second newly developed appliance presented here is the GAMS (Gas‐Migration‐Simulator). Basically comparable to a lysimeter, the difference is that the GAMS allows the detailed investigation of soil‐gas migration processes and their dependence on parameters like the diffusion coefficient and the gas permeability of the soil, alterations of the groundwater level and on various external influences such as changes of the actual meteorological conditions. These two newly developed techniques are described in this paper, and their respective suitability is demonstrated on the basis of data sets recorded during initial experiments.     

Nitrogen Fluxes of a Slope Mire in the German Harz Mountains

Nitrogen (N) fluxes of a slope mire in the German Harz Mountains were monitored to study the effect of increased N deposition on the N retention of the mire. In addition, the N content of mire pore water beneath different plant species was analyzed to assess N retention ability of plants. Atmospheric N deposition at the study site was 4.9?±?0.4 g N m^?2 year^?1 averaged for the study period of 2002 and 2003, with forest stand deposition being the largest share. Discharge was the main output pathway of N with a rate of 1.9?±?0.3 g N m^?2 year^?1. The mire showed a high N retention rate of 67%. Short-term N accumulation rate was 3.9 g N m^?2 year^?1. Differences in mire pore water N concentration under different vegetation cover indicate a lower N retention ability for ombrotrophic Sphagnum plants.     

Soil‐ecological evaluation of willows in a floodplain

Willows (Salix spp.) were supposed to be suitable candidates for the phytoremediation of polluted floodplain soils, but it is unknown how willow growth alters concentrations and mobility of pollutants under the conditions of ongoing periodically flooding. Therefore, effects of willow cropping on total concentrations and mobility of As and heavy metals and soil microbial properties were determined after three and four growing seasons under willows in comparison to native grassland in a flood channel of a River Elbe floodplain (Central Germany). After 4 y of willow coppice, the heavy metal concentrations (mg kg^–1) were increased not only in the grass control plots (final Cu 274, Pb 276, Zn 935) but also under the willows (final Cu 248, Pb 251, Zn 779) compared to the initial concentrations (initial Cu 170, Pb 156, Zn 579). This increase might likely be caused by the ongoing sedimentation by flood events. The smaller increase under willows compared to grass might be related to an initial net effect of phytoextraction. The concentrations of the mobile fractions of Cd, Cu, Ni, and Zn were significantly lower under willows than under grass. Higher β‐glucosidase activities under willows than under grass might indicate a starting net decomposition of organic matter. Therefore, the study of long‐term and large‐scale effects are recommend before an appropriate evaluation of willow short‐rotation coppice for phytoremediation of polluted floodplains will be established.     

Model studies of ferulate-coniferyl alcohol cross-product formation in primary maize walls: implications for lignification in grasses

Ferulate and diferulates mediate cell wall cross-linking in grasses, but little is known about their cross-coupling reactions with monolignols and their role in lignin formation in primary cell walls. Feruloylated primary walls of maize were artificially lignified and then saponified to release ferulate and diferulates and their cross-products with coniferyl alcohol for analysis by GC-FID, GC-MS, and NMR spectroscopy. Ferulate and 5-5-coupled diferulate had a greater propensity than 8-coupled diferulates to copolymerize with coniferyl alcohol, forming mostly 4-O-beta' and 8-beta' and some 8-O-4' and 8-5' cross-coupled structures. Some 8-beta' structures de-esterified from xylans, but these cross-links were subsequently replaced as 8-coupled diferulates formed stable cross-coupled structures with lignin. Based on the incorporation kinetics of ferulate and diferulates and the predicted growth of lignin, cross-products formed at the onset of lignification acted as nucleation sites for lignin polymerization.     

Use of reactive phosphate rocks as fertilizer on acid upland soils in Indonesia: accumulation of cadmium and zinc in soils and shoots of maize plants

A pot experiment was conducted to study the contribution of reactive phosphate rocks (RPRs) on the accumulation of Cd and Zn in 10 acid upland soils in Indonesia and shoots of Zea mays plants grown on these soils. Two types of RPR were used at a rate of 0.5 g (kg soil)^–1: RPRL containing 4 mg Cd kg^–1 and 224 mg Zn kg^–1, and RPRH containing 69 mg Cd kg^–1 and 745 mg Zn kg^–1. Zea mays was harvested at 6 weeks after planting. The application of RPRH significantly increased the concentrations of Cd in the shoots. The application of this RPR also increased the amount of Cd which could be extracted by 0.5 M NH₄‐acetate + 0.02 M EDTA pH 4.65 from the soils. More than 90% of the added Cd remained in the soil. As Zn is an essential element and the studied acid upland soils are Zn‐deficient, increased plant growth upon RPR application might be partly attributed to Zn present in the phosphate rock. However, more experiments are needed to confirm this hypothesis. The Cd and Zn concentrations and CEC of the soils were important soil factors influencing the concentrations of Cd and Zn in the shoots of maize plants grown on these soils.     

Mutations in CIC and FUBP1 contribute to human oligodendroglioma

Oligodendrogliomas are the second most common malignant brain tumor in adults and exhibit characteristic losses of chromosomes 1p and 19q. To identify the molecular genetic basis for this alteration, we performed exomic sequencing of seven tumors. Among other changes, we found that the CIC gene (homolog of the Drosophila gene capicua) on chromosome 19q was somatically mutated in six cases and that the FUBP1 gene [encoding far-upstream element (FUSE) binding protein] on chromosome 1p was somatically mutated in two tumors. Examination of 27 additional oligodendrogliomas revealed 12 and 3 more tumors with mutations of CIC and FUBP1, respectively, 58% of which were predicted to result in truncations of the encoded proteins. These results suggest a critical role for these genes in the biology and pathology of oligodendrocytes.