Soil acidification and element fluxes of a Fagus sylvatica forest as influenced by simulated nitrogen deposition

Water, Air, &; Soil Pollution - The influence of simulated 3- and 9-fold increases in the current N deposition on element fluxes and soil acidification was investigated in a beech forest in S...     

Impact of sedation method on the diagnosis of hip and elbow dysplasia in Swedish dogs

Our objective was to investigate the effect of sedation method on the screening result for hip and elbow dysplasia. The study was based on a questionnaire survey of routines for hip and elbow screening at Swedish veterinary clinics and results of hip and elbow status, for eight breeds (Bernese Mountain Dog, Boxer, German Shepherd Dog, Golden Retriever, Labrador Retriever, Newfoundland, Rottweiler, and Saint Bernard) recorded by the Swedish Kennel Club. In total 5877 and 5406 dogs examined for hip and elbow dysplasia, respectively, from January 2002 through March 2003 were included. We used logistic regression to examine whether the type of chemical restraint used for sedation affected the screening result for hip and elbow dysplasia. In addition to sedation method, the effects of veterinary clinic, sex, breed, and age at screening were studied.

The type of chemical restraint used for sedation affected the screening result for hip but not for elbow dysplasia. Acepromazine gave less than half the odds of hip dysplasia compared with medetomidine and butorphanol (the most common method), medetomidine alone or xylazine. Females had about 25% higher odds for developing hip dysplasia whereas males had almost 40% higher odds for developing elbow dysplasia. Saint Bernard, Newfoundland and German Shepherd Dog had the highest odds of developing hip dysplasia, whereas Rottweiler and Labrador Retriever had the lowest odds. Boxer had the lowest risk for elbow dysplasia, followed by Labrador Retriever. Saint Bernard and Rottweiler had the highest odds of elbow dysplasia. Increasing age increased the odds of both hip and elbow dysplasia, by about 2.5% per month.

Following the results in this study, recording of the type of chemical restraint used for sedation during hip screening has now become mandatory in Sweden. This makes it possible to account for the effect of sedation method in a model for prediction of breeding values for hip dysplasia.     

Swedish long‐term experiments

In 1996 there were 124 individual long‐term experiments in Sweden financed by the Swedish University of Agricultural Sciences to a cost of 648.000 Euro. Of these 39 were plant nutrition and soil fertility experiments distributed between the 54th to the 63rd latitude.

At three sites, south, central and north, N mineralization in cropping systems with ley and manure was investigated. Approximately 90 kg N per ha and year was removed by the crops at all three sites. Temperature, cropping history and ley proportions are factors that influenced the N mineralization. In rotations without ley and manure at the central and south sites the N uptake was around 30 kg per ha and year.

Soil C content decreased during 35 years in the south but changed insignificantly at the central and north sites, 31 and 28 years respectively. Only minor effects on soil C content were observed by increased biomass production due to N fertilization. The efficient C metabolism of the heterotrophic microflora emphasises the significance and importance of the simultaneous ongoing N mineralization for the N supply of crops and for the environment.     

Presence of the di-leucine motif in the cytoplasmic tail of the pig FcRn alpha chain

The sequence of the pig FcRn alpha chain was recently published. The lack of a conserved di-leucine motif in the cytoplasmic tail suggests a rare polymorphism in the described animal, alternatively, a sequencing error. We therefore cloned and sequenced the pig FcRn alpha chain. Our sequence, along with a previous NCBI GenBank submission and five pig derived EST clones clearly demonstrate the presence of di-leucine motif in the cytoplasmic tail of the pig FcRn. No polymorphism in the cytoplasmic tail-encoding region was found in 25 animals from six pig breeds based on single-stranded conformation polymorphism and sequencing analysis, suggesting that the previously described pig FcRn alpha chain may represent a sequencing error in the 3' portion of the gene.     

Performance of the Pseudomonas chlororaphis biocontrol agent MA 342 against cereal seed-borne diseases in field experiments

The bacterial biocontrol agent Pseudomonas chlororaphis, strain MA 342, was tested for activity against a number of cereal seed-borne diseases in a total of 105 field experiments carried out at different locations in Sweden during the years 1991-1996. Bacterial liquid culture was directly applied to pathogen-infested seeds of barley, oats, wheat and rye without additives. The seeds were then dried and sown in field together with fungicide-treated and untreated seeds used as controls. The bacterization controlled seed-borne diseases caused by Drechslera (Pyrenophora) graminea, D. teres, D. avenae, Ustilago avenae, U. hordei, and Tilletia caries, as effectively as guazatine + imazalil, and these effects were consistent over the years and over varying climatic zones. Diseases caused by pathogens like U. nuda, soil-borne T. caries and T. contraversa were not controlled and the bacterization gave less than full effect against diseases caused by Microdochium (Fusarium) nivale, and Bipolaris sorokiniana (Cochliobolus sativus). Bacterized seeds could be stored dry for at least two years without losing the disease suppressing effect of the bacterial treatment, when tested in the field.     

Near-Infrared Reflectance Correlated to 100-g Wet-Milling Analysis in Maize

An understanding of the genetic control of starch, protein, and oil concentrations in the corn (Zea mays L.) kernel is essential for improvement of grain quality. Because large numbers of progenies are needed for genetic studies, a rapid, accurate, analytical procedure is necessary. As part of a study to identify chromosomal regions associated with starch and protein, a rapid near-infrared reflectance (NIR) method and a more labor-intensive 100-g wet-milling procedure were compared for consistency in ranking families and identifying quantitative trait loci (QTL) using a set of 200 F₂S₁ families from the cross of the 70th generations of the Illinois High Protein (IHP) × Illinois Low Protein (ILP) corn strains. NIR starch and wet-milling starch values were highly correlated (r = 0.80), as were NIR protein and gluten measured by wet-milling (r = 0.72). Chromosomal regions associated with NIR starch and wet-milling starch were generally the same. Fiber concentration was significantly negatively correlated with starch and positively correlated with protein. Chromosome regions with significant associations with starch also had significant associations with fiber. The NIR method is satisfactory for measuring starch and protein in material with a wide range of variability in the early stages of a corn-breeding program.     

Single-Stage Short-Duration Tempering of Corn for Dry-Milling

Pilot-scale dry-milling runs were conducted to study the feasibility of using a short-duration single-stage tempering procedure for the tempering-degerminating system, instead of the 17.8–21.5 hr of conventional three-stage tempering procedures reported in the scientific literature. Using a Beall degerminator No. 0, pilot-scale dry-milling experiments were conducted at 10 tempering levels: 0, 5, 10, 15, 30, 45, 60, 120, 180, and 240 min. Variation in moisture content of through- and tail-stock fractions, degerminator throughput, ratio of tail- to through-stock, yields of different sized grits from tail- and through-stock fractions, and the recovery of germ and pericarp were used to compare tempering periods. A decrease in the milling action was observed for tempering durations >30 min. A tempering period of 15 min gave the highest grit recovery and a 30-min tempering period resulted in the highest germ and pericarp recovery. Based on these results, it was concluded that short tempering periods of 10–30 min as compared to 17.8–21.5 hr could be used for the tempering-degerminator system.     

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.     

Landscape ecology as a theoretical basis for nature conservation

Conservation of representative biotopes, single species populations or biodiversity usually embraces two or more biotopes, and is often affected by surrounding croplands. The conclusions from landscape ecological studies can, therefore, offer important contributions to conservation, especially at early levels of landscape change or habitat fragmentation. Indicator and keystone species are useful for monitoring and managing fragmented biotopes, respectively. Communities as well as single species are affected by the juxtaposition of successional and climax biotopes, which influence climatic equability, seasonality, productivity and dispersal. Low levels of fragmentation may result in ill-functioning communities, and greater fragmentation may result in species losses and ultimately in the loss of whole communities. Fragmented habitats retain species with high reproductive and dispersal rates and generalized habitat selection. New combinations of interacting species will lead to trivialization of earlier habitat-specific interactions. Validation of these concepts was made with data from a Swedish research program on fragmented biotopes in production landscapes. General reserve selection and methods of management for preserving climax communities, single specialized species and high biodiversity are suggested.