Interspecies calibration of heavy-metal concentrations in nine mosses and lichens:-Applicability to deposition measurements

The study describes a method for including nine alternative moss and lichen species in heavy-metal air-pollution surveys based on concentrations in one of the species. Iron, Cu, Zn, Pb, Ni and Cd concentrations have been measured in Dicranum polysetum, Hylocomium splendens, Hypnum cupressiforme, Pleurozium schreberi, Pohlia nutans, Cladonia rangiferina, Hypogymnia physodes, Pseudevernia furfuracea and Usnea filipendula from 57 sites in coniferous woodland surrounding a brass foundry in Sweden. Concentrations vary decidedly between species. The mosses frequently show higher concentrations than the lichens. The use of different monitor species in a deposition survey without interspecies calibration is not advised. Calibration factors for concentrations in different species can be calculated from the mean concentrations in each species. With the help of the factors, concentrations in a species not found in a certain site can be estimated from concentrations measured in any of the other species sampled. The applicability of the reported calibration factors to surveys in other regions is discussed. Where these factors are not applicable, local calibration factors for indicator species of interest can be set up using the method presented.     

Mammal movements and foraging at remnant woodlands inside coniferous forest landscapes

Temporary or spatially restricted resources may affect population densities over more or less wide areas in the surrounding landscape or region. They may affect more than one trophic level by facilitation of predation. Areas of influence may differ between species. Such effects of mast-seeding in confined oak–hazel woodlands were examined for a guild of mainly seed-eating mammals and their predators. The mammals were tracked in snow in winter and the foraging of granivorous small mammals was assessed by experimental seed supplies in spring and autumn. Movements and foraging at various locations in and around the woodlands were distinguished from large-scale influences in the surrounding conifer forest landscape. Roe deer moved more abundantly inside the woodlands than in the conifer forest 50 m away and, less clearly, this was also the case for granivorous small mammals. Squirrels were particularly common at the edges while brown hares were somewhat less common at these edges. The edge effects appear therefore species-specific. Brown hares, squirrels, voles and granivorous small mammals were generally less common in the coniferous forest more than 500 m from the woodlands than in the coniferous forest 50 m from the woodlands. The most common generalist predator, the red fox, was as a mean equally common at all locations. However, it demonstrated a spatio-temporal variation in movements related to hare and, to a lesser extent, squirrel occurrence at open woodland sites. In order to sustain several mammalian species in conifer forest landscapes, not only granivorous ones, resource patches of oak and hazel should be retained, regenerated and, if possible, expanded. Such hot spots often need particular management.     

Affinity and rate constants for interactions of bovine folate-binding protein and folate derivatives determined by optical biosensor technology. Effect of stereoselectivity

The interactions between bovine folate-binding protein (FBP) and different folate derivatives in pure diastereoisomeric forms were studied at pH 7.4 by a surface plasmon resonance technology (Biacore). The results show that folic acid had the most rapid association rate (k(a) = 1.0 x 10(6) M(-)(1) s(-)(1)), whereas (6S)-5-HCO-5,6,7,8-tetrahydrofolic acid had the most rapid dissociation rate (k(d) = 3.2 x l0(-)(3) s(-)(1)). The equilibrium dissociation constant (K(D)), calculated from the quotient of k(d)/k(a), showed that the two forms of folates not occurring in nature, that is, folic acid and (6R)-5-CH(3)-5,6,7,8-tetrahydrofolic acid, had the highest affinities for FBP, 20 and 160 pmol/L, respectively. The results thus show that there were great differences in the interactions between folate-binding protein and the major forms of folate derivatives. The nutritional implications of these differences are discussed.     

Effect of Hybrid and Physical Properties of Individual Popcorn Kernels on Expansion Volume

The relationships between expansion volume and physical properties of three varieties of popcorn kernels were investigated on a single kernel basis. Physical properties studied were kernel size, kernel sphericity, and kernel density. Methods of measuring densities and popped volumes of individual popcorn kernels were developed. Popcorn kernels were separated into seven kernel sizes by screening with round‐hole sieves. Thirty kernels from each of three kernel sizes (4.76 < D < 5.16, 5.56 < D < 5.95, 6.35 < D < 6.75 mm) of three popcorn varieties were individually measured for sphericity, density, and popped volume. Density and sphericity measures of popcorn kernels showed little variability. Variety, kernel sphericity, and kernel density had minor effects on expansion volume. Kernel size had no effect. There were no strong linear relationships (R² = 0.28) among expansion volume and physical properties of the three varieties of popcorn kernels. The variety with the highest mean density and the highest mean sphericity showed a tendency of producing higher mean expansion volumes.     

Reducing Steep Time by Adding Lactic Acid During Countercurrent Steeping of Corn with Different Initial Moisture Contents

Reducing corn steep time by adding lactic acid instead of relying on in situ fermentation was studied. Corn at two initial moisture levels (15 and 20%) was steeped for 18 hr in a countercurrent steep system. The initial SO₂ target concentration in steepwater was 2,000 or 3,000 ppm, while the initial lactic acid concentration in steepwater was 0, 0.28, or 0.55%. Adding lactic acid under all steeping conditions decreased steepwater pH, accelerated SO₂ absorption, and increased the amount of solids released from corn. Adding lactic acid during steeping also increased the first grind slurry density and made germ skimming easier than when no lactic acid was added. Starch yields for the hybrid used in this study under all steep conditions were comparable to those from 24‐hr steeping, except when steeping corn with an initial moisture content of 15% in ≈2,000 ppm of SO₂ alone. For the 20% moisture corn, adding lactic acid to fresh steepwater significantly improved the starch yield at ≈2,000 ppm of SO₂ for 18‐hr steeping. At ≈3,000 ppm of SO₂, adding lactic acid did not increase the starch yield for the hybrid used. The protein content in starch was significantly lower when lactic acid was added. Pasting properties of starch were not affected by adding lactic acid. The hybrid used in this study had an initial moisture content of 20% and could be wet‐milled without affecting starch yield, starch protein content, and pasting properties.     

Biobeds for environmental protection from pesticide use--a review

Biobeds originated in Sweden in response to the need for simple and effective methods to minimize environmental contamination from pesticide use, especially when filling spraying equipment, a typical point source of contamination. The biobed system has attracted attention in several countries, where work is being conducted to adapt it to local conditions and applications. As a consequence, the biobed system has been more or less modified and sometimes renamed, for example, as biomassbed in Italy, biofilter in Belgium, and Phytobac and biobac in France. The effectiveness and simplicity of the biobed also make it suitable for use in developing countries, and different adaptations of the biobed concept now exist in, for instance, Peru, Guatemala, and Ecuador. When the modification of the biobed includes an intention to use it for retention and degradation of pesticides in sprayer washings, the construction has to be adapted to, for example, lined biobeds to ensure that no pesticide leaching will occur. Replacement of some of the original materials in the Swedish biomixture (straw, peat, and soil) can also change the performance of the system, for instance, the amount, activity, and composition of the microbial community that develops. This review presents the state of the art of biobeds and similar systems in Sweden and worldwide and identifies future research needs. Factors affecting the efficiency of biobeds in terms of degradation and retention of pesticides are discussed, with particular emphasis on the microbial processes involved.     

Compatibility of the ammonium lactate (AL) and sodium bicarbonate (Olsen) methods for determining available phosphorus in Swedish soils

Abstract

Plant-available P was first extracted in soils 114 years ago and a number of different analytical methods have since been developed, but for good reasons none of these methods has been adopted as a standard for all soils. With increasing cooperation within research, there is a need to harmonise the interpretation of analytical data for fertiliser recommendations, research, and environmental control. This paper evaluates the compatibility of the Swedish standard ammonium lactate (P_AL) method and the widely used Olson's sodium bicarbonate (P_Ols) method in 82 topsoil samples taken from Swedish long-term soil fertility field trials. The P_AL-values were usually larger than P_Ols, with a mean P_AL/P_Ols quotient of 2.30±1.04 (0.67–6.58). The P_AL and P_Ols means and ranges were 126±89 (5–360) and 55.1±33 (3.1–122.8) mg P kg^?1 dry soil, respectively. Stepwise multiple linear regression analysis was used to evaluate the relationship between P_AL and P_Ols and how this relationship was affected by clay content, pH, and soil organic carbon content (SOC). After statistical transformation, it emerged that the square root of clay content (17.4%±13.82, range 1–54.4) and pH (6.45±0.54, range 5.5–7.7) significantly affected the relationship at partial R ²-values of 2 and 12%, respectively, while ln(SOC) (2.54%±1.21, range 1–6.03) did not, apparently due the narrow range. The regressions of predicted vs. measured values explained 95 and 94% of the variation in P_AL and P_Ols, respectively. The mean deviation of predicted compared with measured values was 21.3 and 8.3 mg P kg^?1 dry soil for P_AL and P_Ols, respectively, corresponding to 20 or 19% of the measured values. We conclude that a data set consisting of P_AL-values can be converted into P_Ols-values and vice versa with reasonably high accuracy when accounting for clay content and pH.     

Economics of Germ Preseparation for Dry-Grind Ethanol Facilities

A detailed economic analysis of a 914 tonnes/day (36,000 bu/day) “Quick Germ” ethanol process was performed. The Quick Germ ethanol process is a combination of a dry-grind and a wet-milling ethanol process. The Quick Germ ethanol process increases the coproduct value in the dry-grind ethanol process by recovering germ before fermentation. Germ is recovered using the conventional wet-milling degermination process. Economic assessment of the Quick Germ process proved profitable. The savings achieved by recovering germ as a coproduct and by increasing the fermentor capacity due to removal of nonfermentables from the corn mash will reduce the manufacturing cost of ethanol by 2.69 ¢/L (10.19 ¢/gal or $0.265/bu) when compared to the conventional dry-grind ethanol process.