Carbon dioxide and climate: the importance of realistic geography in estimating the transient temperature response

Results obtained from a detailed air-sea-ice climate model for an instantaneous increase in the atmospheric carbon dioxide content are used to estimate the transient surface temperature response for several time-dependent carbon dioxide increase scenarios. The inclusion of realistic variations of land fraction and ocean mixing with latitude is found to limit the applicability of steady- state simulations as approximate guides to the actual time-dependent temperature response, particularly when the regional response is considered.     

Discovery of a new gravitational lens system

A new gravitational lens system, the triple radio source MG2016+112, has been discovered. Five emission lines at a redshift of 3.2733+/-0.0014 have been identified in the spectra of two stellar objects of magnitude 22.5 coincident with radio components 3.4 arc seconds apart. The lines are the narrowest ever observed in objects at such a large redshift. The redshift of a 23rd-magnitude extended optical object coincident with the third radio component has not been determined spectroscopically, but its known optical properties are consistent with those of a giant elliptical galaxy with a redshift of about 0.8.     

Triticonazole distribution in dressed corn caryopsis and seedlings

A corn seed dressing with the fungicide triticonazole at 760 nmol/seed prevents head smut disease. In resting seeds, the dressing treatment was followed by the penetration of 19% of the product, 9% inside the tegument and 7% inside the pedicel. In growing seedlings, the inner content increased in the storage organs (endosperm + scutellum) as well as in the growing organs. The partition lipophilic phase/water certainly explains the high apparent fungicide concentration progressively reached inside endosperm and scutellum. However, no important transfer of fungicide from these organs to the growing parts seems to occur. It appears therefore that the fungicide transfer from the coating to the roots mostly occurs through dissolution of the product in the surrounding soil water and through root absorption. The efficient fungicide concentration inside the meristem is likely to be obtained during the early stages of development.     

Comparing 1H‐NMR imaging and relaxation mapping of German white asparagus from five different cultivation sites

Nuclear magnetic resonance imaging (MRI) and complementary analytical techniques were used to address the question whether white asparagus (Asparagus officinalis L.) from different cultivation sites in Germany can be distinguished on the basis of NMR relaxation times. Five locations with contrasting soil properties and composition within the two asparagus‐cultivation regions Rhineland and Lower Franconia were selected for this project. For the first time, entire asparagus plants in their authentic soil environment excavated directly from the original harvest site were imaged by the NMR technique. However, they could not be employed for determination of relaxation times of spears in situ, because of artifacts arising from soil properties. Instead, market‐ready asparagus spears and freshly prepared spear saps from the five locations were used to acquire MRI data sets with different (slow and fast) imaging methods and to compute spatially resolved distributions (maps) of T₁, T₂, and T₂* relaxation times. Comparison of the data for pith, vascular tissue, and peel of the spears yielded only marginal, if any, differences in T₁, T₂, and T₂* between the specimens from the five locations, which were not sufficient for an unambiguous region‐related distinction. More pronounced differences in T₁, T₂, and T₂* were visible for the spear saps, allowing a clear distinction between individual specimens for each of the two cultivation regions. The results are discussed in terms of an application potential for correlated NMR relaxation times of tissue saps for future geographic authentication of agricultural produces.     

Acid precipitation and surface-water vulnerability on the western slope of the high colorado rockies

Precipitation and surface waters in a high-elevation watershed on the western slope of the Colorado Rockies were studied over a three-year period. The volume-weighted average pH for summer events was 4.61, for winter events was 5.11 and for the entire period was 4.91. Within the watershed, both low- and medium-alkalinity surface waters exist. Weekly alkalinity measurements ranged from 10 to 70 μeq L^?1 in the former and 100 to 900 μeq L^?1 in the latter.     

Heavy metal contamination of soils in a mining area in South Africa and its impact on some biotic systems

In soils, animals and plants from selected sites in the Rustenburg mining area, a part of the South African ore belt, the heavy metal burden was examined. These sites belong to different soil types and are characterized by different land-use (agriculture, grassland). The heavy metal contamination of the soil samples is relatively high and is dominated by chromium and nickel, metals, which are extracted in the mine near the sampling sites. These high heavy metal concentrations had no clear inhibitory influence on micro-organisms or the enzyme activity of soils. It appears that the high clay content of the soils may counteract the influence of heavy metals. On the other hand, tolerant microbial populations may have been established. In addition, the investigated culture plants there was no correlation between the heavy metal content of the soils and the concentrations in roots and shoots. The dangerous, potential contamination of organs in humans seems to be modest, with the exception of tobacco leaves. The heavy metal content of tissues in the examined animals reflect the environmental habitat in situ with no obvious influence on the health of the animals.     

Fermentation of cottonseed and other feedstuffs in cattle rumen fluid

Bovine rumen fluid was fermented anaerobically over 48 h with cottonseed, corn, alfalfa, or a mixture of these substrates in anaerobic mineral buffer. Samples taken at different incubation times were derivatized with n-butanol and subjected to gas chromatography and mass spectroscopy. No unusual fermentation end-products from the cottonseed substrate were detected. Cottonseed supported rumen fermentation at levels comparable to those of the other substrates. Major components were usually found in the decreasing order of acetate, propionate, butyrate, and valerate, although acetate and propionate concentrations decreased late in the alfalfa and mixed-feed fermentations, eventually allowing butyrate concentrations to exceed those of propionate. As expected, lactate was produced in high concentrations when corn was fermented. The minor components 2-methylpropionate, 2- and 3-methylbutyrate, phenylacetate, phenylpropionate, and caproate also accumulated, with their relative concentrations varying with the substrate. Succinate was produced in substantial amounts only when corn and alfalfa were fermented; it did not accumulate when cottonseed was the substrate. Samples containing cottonseed were derivatized and subjected to reversed-phase high-performance liquid chromatography, revealing that gossypol concentrations did not change during fermentation.     

Vorkommen und Haltung der ?stlichen Honigbiene (Apis cerana Fabr.) in Afghanistan

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