The Application of Multivariate Statistical Methods for the Evaluation of Soil Profiles (8 pp)

Background, Aim and Scope   Contamination of soils does not only occur on their surface over large areas, but also in depth. Therefore a characterization of soil state after pollution demands a three-dimensional soil sampling, by what a large number of samples has to be analyzed. Analytical results could be evaluated by multivariate statistical methods, which have already been used for the evaluation of data sets containing results from soil sampling of two dimensions like areas or single profiles. In this case study, multivariate statistical methods were applied to investigate structure and interactions between features in a data set containing results of three-dimensional soil sampling. The investigated soil profiles were contaminated by emissions of a former cement and phosphate fertilizer plant. The aim of this study was to determine the remaining extent of contamination and to analyze whether pollutants are mobilized and vertically transported within the profiles. Materials and Methods: Three soil profiles were sampled in the surroundings of the plant. Grain size, organic and carbonatic bonded carbon, pH value, and the total contents of Ca, Cd, Co, Cu, F, Fe, K, Mn, Mg, Na, Ni, P, Pb, and Zn were determined. The resulting data set was evaluated by cluster analysis, linear discriminant analysis, and principal components analysis. The sequential extraction procedure according to Zeien and Brümmer was applied to analyze the binding properties of Ca, Cd, Cu, Na, Pb, and Zn from selected samples. Results: Cd was identified as contaminant of the top soils. The pH values of the bottom soils were determined to be in alkaline range, which is unnaturally high. Variables were clustered according to enrichment of variables in top soils. The samples were classified regarding their pollution state and their substrate by cluster analysis, which was confirmed by linear discriminant analysis. Geogenic and anthropogenic sources of variables as well as relationships between variables like the binding of heavy metals at organic matter were detected by using principal components analysis. The binding of heavy metals at organic matter in the top soils was confirmed by the results of the applied sequential extraction. A vertically altered distribution of Na binding was determined. Discussion: According to the current soil conditions, the uptake of heavy metals had probably occurred by the over ground part of plants during the deposition. The distribution of Na should likely result from the vertical transport of Na, which would also explain the high pH values of the bottom soils by ion exchange. Altogether, the main amount of deposited Ca, F, Na, P, and heavy metals is likely nearly insoluble bound in the top soils. Conclusions: Ten years after the end of production, the pollution of top soils in the surroundings of the former plant is still high. However, regarding the ecotoxicological relevance the now explored interactions between several soil features and elements strongly indicate that there is no short-term to medium-term risk of a mobilization of the deposited elements with the exception of Na. Recommendations and Perspectives: The results of this case study prove that multivariate statistical methods are powerful tools to explore interactions of variables and relationships in a data set derived from three dimensional soil sampling. The methods applied in this work can be highly recommended for evaluations of large data sets resulting from two- or three-dimensional samplings. Multivariate statistical methods enable the characterization of soils and their pollution state in a simple and economic way.     

Adherence, haemagglutination and cell surface characteristics of motile aeromonads virulent for fish

Abstract. Motile Aeromonas spp. virulent for fish were studied with regard to their adhesion profile. Electron microscopy demonstrated the presence of fimbriae (pili) on Aeromonas cells regardless of virulence potential. The results show no significant correlations between ability to haemagglutinate, yeast cell co-agglutination and virulence. All strains expressed mannose-sensitive haemagglutinin activity against guinea pig erythrocytes. Using four types of red blood cells no characteristic haemagglutinin pattern related to virulence could be discerned. Expression of surface haemagglutin(s) on Aeromonas hydrophila appears to be medium dependent; strains grown in liquid media demonstrated enhanced haemagglutination activity. Both virulent and avirulent strains had in vitro epithelial cell adhesive capabilities. Cell surface characteristics measured by agglutination in acriflavine and stability after boiling indicated that most virulent strains agglutinated in the presence of acriflavine, but not all sedimented after boiling. The ability of 10 selected strains of A hydrophila to grow in normal pooled catfish serum was determined. Only 17% of the virulence variations can be explained by their sensitivity to serum.     

Asynchronous growth of the canine radius and ulna: effects of retardation of longitudinal growth of the radius.

After 2,000 rads of x-radiation to the right distal radial physis of eight 70-day-old dogs, the longitudinal growth of the right radius was retarded 42.1% when compared with the growth of the nonirradiated left radius. Asynchronous growth of the right radius and ulna resulted. The gross and radiographic changes that occurred over the subsequent 75 days were described. Subluxation of the humeroradial and humeroulnar joints occurred and was first observed 31 days after irradiation. By 75 days after irradiation, the radius was puller 7.8 mm distally by the radioulnar ligament. However, subluxation of the humeroradial joint was minimized by accelerated growth from the proximal radial physis and articular cartilage. Acceleration of growth also occurred at the distal radial articular cartilage. Growth from the distal ulnar physis and styloid process was retarded. It was thus apparent that after retardation of growth from the distal radial physis, considerable adjustment occurred in the relationship between the radius and the ulna and also in growth from their other physes, which reduced the deleterious effects of the growth retardation.     

Increased emergence of spring wheat after inoculation with Pseudomonas chlororaphis isolate 2E3 under field and laboratory conditions

Inoculation at the time of planting with Pseudomonas chlororaphis strain 2E3 increased the emergence of spring wheat by 8% and 6% at two different sites in northern Utah. Isolate 2E3 strongly inhibited the growth of the wheat pathogen Fusarium culmorum on artificial media. A second isolate of P. chlororaphis (strain O6) also inhibited fungal growth on artifical media but did not increase emergence of the spring wheat at the same field sites. Inoculation of winter wheat by 2E3 did not promote emergence when planted into field soil sterilized by fumigation with methyl bromide. Under laboratory conditions, emergence of spring wheat in sterilized soils from both sites was at least 90%. In the soils that were not sterilized, emergence was below 25% in soil from one site and below 50% in soil from the other. Treating seeds with 2E3 significantly improved emergence in a sterile soil-containing matrix that had been inoculated with the wheat pathogen Fusarium culmorum. Consequently, we propose that increases in wheat emergence can be attributed to the suppression by 2E3 of pathogenic organisms present in the native field soils. A strain of Rhizoctonia solani, shown to the pathogenic on winter wheat, was isolated from one of these soils.     

Seed Shattering of Cañahua (Chenopodium pallidicaule Aellen)

Cañahua (Chenopodium pallidicaule Aellen) is a semi‐domesticated relative of quinoa (Chenopodium quinoa Willd.) with high nutritious quality. It is tolerant to frost, drought, saline soils and pests. One seed yield limitation is seed loss during the maturity stages. Two greenhouse experiments in Denmark and field experiments in Bolivia were carried out to determine seed shattering in landraces and cultivars with different growth habits. 15–21 % of the seed shattering in the fields took place whilst the plants still were flowering and 25–35 % during physiological maturity. Seed shattering varied between locations on the Bolivian Altiplano. Cañahua types with the semi‐prostrate growth (‘lasta’) had the highest seed shattering rate in the greenhouse experiments. The Umacutama landrace had lower seed shattering (1 %) than the cultivar Kullaca (7.2 %) both of the ‘lasta’ type. Under field conditions, the cultivar Illimani with the erect growth (‘saihua’) had the highest seed shattering rate (6.4–33.7 %) at both locations and at four different sowing dates. The Umacutama had the lowest rate (0.5–1.5 %). There were no significant differences between plants of the ‘lasta’ and the ‘saihua’ types. The landrace had significantly less seed loss than the cultivars. However, in the greenhouse, the landrace yield was approximately 25 % lower than the yields of the cultivars. In general, cañahua cultivars had higher yield compared to landraces, but also a higher seed shattering rate. Landraces may be used in breeding programmes to develop high‐yielding cultivars with reduced seed shattering.     

Genetic analysis of vesicular stomatitis virus-New Jersey from the 1995 outbreak in the western United States

OBJECTIVE: To compare molecular associations between the vesicular stomatitis virus (VSV)-New Jersey isolates of the 1995 outbreak with those from previous outbreaks between 1982 and 1985 in the western United States. SAMPLE POPULATION: 23 virus isolates considered representative of the 1995 outbreak of vesicular stomatitis. PROCEDURE: Viral gene coding for surface-envelope protein G was evaluated by use of nucleotide sequencing and phylogenetic analysis. RESULTS: Changes in up to 0.77% of the nucleotide bases and 1.35% of the amino acids were detected among the 1995 viral isolates, whereas changes in up to 3.2 and 2.9% of the nucleotides and amino acids, respectively, were found, compared with the 1982 to 1985 viruses. Insertions or deletions were not found in the entire gene, which spanned 1,554 nucleotide bases. CONCLUSIONS AND CLINICAL RELEVANCE: Phylogenetic analysis indicated that the 1995 VSV-New Jersey belongs to a lineage distinct from that of the 1982 to 1985 viruses that caused previous outbreaks in the western United States. Furthermore, it also is distinct from strains from Central America and from the Georgian Hazelhurst strain.     

Examination of the relationship between the estrogen receptor gene and reproductive traits in swine

The relationship between estrogen receptor (ESR) genotype and reproductive traits in a population of Yorkshire, Large White, and crossbred animals was studied. Reproductive tract and litter data were analyzed for associations with ESR genotype, parity, and breed. Forty-six Yorkshire, 31 Large White, and 70 crossbred females from the above population were mated to Hampshire boars and slaughtered at 75 d of gestation. Data collected included ovulation rate, uterine horn length, number of fetuses, fetal weight, uterine weight, number of mummies, fetal sex, fetal placement, fetal survival, and fetal space. Data were analyzed using a model that included the fixed effects of ESR genotype, breed, parity, and all significant two-way interactions. Litter data representing 212 litter records were analyzed in a model that included the fixed effects of ESR genotype of dam, parity, farrowing month, dam breed, sire breed, and all significant two-way interactions. The ESR genotype was significantly associated with the total litter weight of piglets born and total litter weight of piglets born alive. Dams with the AA genotype had significantly (P = 0.04) heavier litters at birth (14.44 +/- 0.36 kg) than dams with the BB genotype (13.43 +/- 0.47 kg). Ovulation rate was significantly (P < 0.05) different between animals of parity 1 (17.22 +/- 0.41) and parity > or = 3 (19.92 +/- 0.85). Significant breed effects were observed for fetal weight, with purebred Large White animals having a greater fetal weight per horn (3,909 +/- 114 g) than purebred Yorkshire animals (3,553 +/- 92 g). Notable, but nonsignificant, trends with respect to ESR genotype were also observed for number of piglets alive at weaning and total litter weight at weaning. The ESR gene is positively associated with several previously uninvestigated reproductive traits.     

Metabolism and residue depletion of albendazole and its metabolites in rainbow trout, tilapia and Atlantic salmon after oral administration

Metabolic and residue depletion profiles of albendazole (ABZ) and its major metabolites in three fish species, rainbow trout, tilapia and Atlantic salmon are reported. Based on these profiles, similarities (or dissimilarities) between species will determine the potential to group fish species. ABZ at 10 mg/kg body weight was incorporated into fish food formulated in a gelatin base or in gel capsule and fed as a single dose to six fish from each species. Rainbow trout were held three each in a partitioned 600-L tank. Tilapia and Atlantic salmon were housed in separate 20-L tanks. Samples of muscle with adhering skin were collected at 8, 12, 18, 24, 48, 72, and 96 h postdose from trout kept at 12 degrees C, at 4, 8, 12, 24, 48, 72, 96, 120, and 144 h postdose from tilapia kept at 25 degrees C and at 8, 14, 24, 48, 72, and 96 h postdose from Atlantic salmon kept at 15 degrees C. The samples were homogenized in dry ice and subjected to extraction and cleanup procedures. The final extracts were analyzed for parent drug ABZ and its major metabolites, albendazole sulfoxide (ABZ-SO), albendazole sulfone (ABZ-SO2) and albendazole aminosulfone using high-performance liquid chromatography with fluorescence detection. ABZ was depleted by 24 h in trout and tilapia and by 48 h in salmon; ABZ-SO, a pharmacologically active metabolite, was depleted by 48 h in tilapia, by 72 h in rainbow trout and was present until 96 h in salmon; and low levels of ABZ-SO2 and albendazole aminosulfone, both inactive metabolites, were detectable at least till 96 h in all three fish species.     

Rheological properties and characterization of polymerized whey protein isolates.

Whey protein polymers were formed by heating whey protein isolate solutions at 80 degrees C. Flow behaviors of whey protein polymers produced from different protein concentrations and heating times were comparable to various flow behaviors of hydrocolloids. Polymer formation was found to be a two-phase process. The initial protein concentration was a significant factor that determines the size and/or shape of the primary polymer in the first phase as shown by intrinsic viscosity. Heating time was a factor in determining the aggregation in the second phase as shown by apparent viscosity. Intrinsic viscosity of whey protein polymers was as high as 141.7 +/- 7.30 mL/g, compared to 5.04 +/- 0.20 mL/g for native whey proteins. The intrinsic viscosity and gel electrophoresis data suggested that disulfide bonds played an important role in whey polymer formation.