Digital soil mapping using artificial neural networks

In the context of a growing demand of high‐resolution spatial soil information for environmental planning and modeling, fast and accurate prediction methods are needed to provide high‐quality digital soil maps. Thus, this study focuses on the development of a methodology based on artificial neural networks (ANN) that is able to spatially predict soil units. Within a test area in Rhineland‐Palatinate (Germany), covering an area of about 600 km², a digital soil map was predicted. Based on feed‐forward ANN with the resilient backpropagation learning algorithm, the optimal network topology was determined with one hidden layer and 15 to 30 cells depending on the soil unit to be predicted. To describe the occurrence of a soil unit and to train the ANN, 69 different terrain attributes, 53 geologic‐petrographic units, and 3 types of land use were extracted from existing maps and databases. 80% of the predicted soil units (n = 33) showed training errors (mean square error) of the ANN below 0.1, 43% were even below 0.05. Validation returned a mean accuracy of over 92% for the trained network outputs. Altogether, the presented methodology based on ANN and an extended digital terrain‐analysis approach is time‐saving and cost effective and provides remarkable results.     

Impact of climate change on the temporal and regional occurrence of Cercospora leaf spot in Lower Saxony

Journal of Plant Diseases and Protection - The effect of climate change on the temporal and regional occurrence of Cercospora leaf spot (CLS) of sugar beet in Lower Saxony is analysed using the...     

Comparison of estimated breeding values, daughter yield deviations and de-regressed proofs within a whole genome scan for QTL

An important issue in quantitative trait loci (QTL) detection is the use of phenotypic measurement as a dependent variable. Daughter yield deviations (DYDs) as the unit of choice are not available for all traits of interest. The use of de-regressed proofs (DRPFs) of estimated breeding values (EBVs) is an alternative to using daughter yield deviations. The objective of this study was to examine possible differences between DYDs and DRPFs within the use of QTL detection. The pedigree used was part of the granddaughter design of the German QTL effort. Consisting marker maps for livestock species were derived from all available data of 16 German Holstein paternal half-sib families with a total of 872 sires. The number of progeny ranged from 19 to 127. A whole genome scan was performed using weighted and unweighted multimarker regression with DYDs, DRPFs and EBVs as dependent variables for the traits milk, fat and protein yields. Results were compared with respect to the number of QTL detected. A similar number of QTL was detected with DRPFs and DYDs. Also, when dependent variables were weighted according to the variance of the trait, a higher number of QTL was detected at the desired level of significance as compared to using unweighted variables.     

Competition modifies effects of enhanced ozone/carbon dioxide concentrations on carbohydrate and biomass accumulation in juvenile Norway spruce and European beech

Elevated concentrations of carbon dioxide ([CO2]) and ozone ([O3]) affect primary metabolism of trees in opposite ways. We studied their potential interactions on carbohydrate concentrations and contents. Two hypotheses currently under debate were tested. (1) Stimulation of primary metabolism by prolonged exposure to elevated [CO2] does not compensate for the adverse effects of O3 on carbohydrate accumulation and biomass partitioning to the root. (2) Growth in a mixed-species planting will repress plant responses to elevated [O3] and [CO2] relative to conditions in a monoculture. To this end, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) saplings grown under conditions of intra- and interspecific competition were pre-acclimated for 1 year to ambient or elevated [CO2]. In the following 2-year phytotron study, trees were exposed to factorial combinations of ambient and elevated [O3] and [CO2]. The total carbohydrate content (sugar and starch) of spruce was greater in plants exposed to elevated [CO2] than in plants exposed to ambient [CO2]. In beech, the opposite response was observed, especially when this species was grown in combination with spruce. Overall, the data did not support Hypothesis 1, because the adverse effects of O3 were counteracted by elevated [CO2]. Support for Hypothesis 2 was species-dependent. In beech saplings, reduction of carbohydrates by elevated [O3] and stimulation by elevated [CO2] were repressed by competitive interaction with spruce. In contrast, in spruce, stimulation of carbohydrates by elevated [CO2] was similar in mono- and mixed cultures. Thus Hypothesis 2 was supported for beech but not spruce. We conclude that, in juvenile beech and spruce, a 3-year exposure to elevated [CO2] counteracts the adverse effects of O3 on carbohydrate concentrations and contents. For beech, sensitivity to elevated [CO2] and [O3] was high in monoculture but was largely repressed by interspecific competition with spruce. In contrast, the response of spruce to perturbations of atmospheric chemistry was not significantly affected by either intra- or interspecific competition.     

Calculation of identity‐by‐descent probabilities of short chromosome segments

For some purposes, identity‐by‐descent (IBD) probabilities for entire chromosome segments are required. Making use of pedigree information, length of the segment and the assumption of no crossing‐over, a generalization of a previously published graph theory oriented algorithm accounting for nonzero IBD of common ancestors is given, which can be viewed as method of path coefficients for entire chromosome segments. Furthermore, rules for setting up a gametic version of a segmental IBD matrix are presented. Results from the generalized graph theory oriented method, the gametic segmental IBD matrix and the segmental IBD matrix for individuals are identical.     

Investigations on functional traits in Simmental: 1. Treatment costs for ten different diseases

SUMMARY: All health-related events and treatment costs (by veterinarian and non-veterinarian) were recorded through fortnightly interviews with the herdsmen of 104 Simmental dairy farms in Upper Bavaria from autumn 1987 to spring 1990. The data include 8381 calvings and the subsequent time period. For ten different disease-classes the sum of all treatment costs from calving up to either the subsequent calving or up to culling were computed. A multiplicative model with three covariates was fitted to these observations. The covariates are farm, parity and type of end of lactation (culling or subsequent calving). Farm effects are significant for almost all diseases. The average sum of treatment costs per calving with an associated disease was estimated as the average expected value for this sum, where averaging is over the farms. These costs range from 29 DM (claw disorders) up to 137 DM (dystocia). The average costs per calving (with or without disease) range from 1.59 DM (injuries of the udder) to 10.90 DM (fertility problems). Corresponding costs per cow and year are 1.74 DM and 12.24 DM. ZUSAMMENFASSUNG: Auf 104 Fleckviehbetrieben wurden insgesamt 8381 Kalbungen, alle auf diese Kalbungen folgenden Erkrankungen und die zugeh?rigen Behandlungskosten erhoben. Für zehn verschiedene Erkrankungsarten wurden jeweils alle Behandlungskosten innerhalb einer Zwischenkalbezit aufsummiert. An diese Beobachtungswerte wurde jeweils ein multiplikatives Modell mit den Einflu?faktoren Betrieb, Laktationsnumner und Art der Zwischenkalbezeit (beendet durch Kalbung bzw. durch Abgang) angep?t. Im Gegensatz zu den beiden anderen Faktoren erweist sich der Betrieb bei fast allen Erkrankungsarten als signifikant. Die durchschnittlichen Kosten innerhalb einer betroffenen Zwischenkalbezeit wurden als durchschnittlicher Erwartungswert über alle Betriebe berechnet. Diese Kosten liegen je nach Erkrankungsart in einem Bereich, der von ca. 29 DM (Klauenerkrankungen) bis zu ca. 137 DM (Schwergeburt) reicht. Umgerechnet auf eine beliebige Kalbung (mit oder ohne folgende Erkrankung) entstehen Kosten zwischen 1,59 DM (Euterverletzungen) und 10,90 DM (Fruchtbarkeitsprobleme). Je Kuh und Jahr betragen die entsprechenden Werte 1,74 DM und 12,24 DM.     

The number of ribs and vertebrae in a Piétrain cross: variation, heritability and effects on performance traits

In a three‐generation experiment with five purebred Piétrain boars and one Landrace, one Large White and 12 Landrace × Large White crossbred sows as founder animals the number of ribs and presacral vertebrae was determined. These numbers were recorded for 111 F₁‐animals and for 2711 F₂‐animals. The number of ribs varied from 13 to 17 and the number of presacral vertebrae ranged from 26 to 30. Means of 15.5 for the number of ribs and 28.6 for the number of vertebrae with a standard deviation of 0.6 for both were calculated. Bayesian heritability estimates were 0.51 for the rib number and 0.62 for the vertebrae number. A phenotypic correlation of 0.76 and a genetic correlation of 0.97 indicated a close relationship of both traits. In additional analyses possible direct or linked effects of rib and vertebrae number on different growth and carcass traits were investigated. Significant effects were found for several traits related to growth, fatness, muscularity and meat quality. Genes for the presacral vertebrae number or linked quantitative trait loci (QTL) accounted for 11.5% of the phenotypic variation in carcass length and for 2.4% of the phenotypic variation in ham weight.     

The Chemically Synthesized Ageladine A-Derivative LysoGlow84 Stains Lysosomes in Viable Mammalian Brain Cells and Specific Structures in the Marine Flatworm Macrostomum lignano

Based on the chemical structure and the known chemical synthesis of the marine sponge alkaloid ageladine A, we synthesized the ageladine A-derivative 4-(naphthalene-2-yl)-1H-imidazo[4,5-c]pyridine trifluoroacetate (LysoGlow84). The two-step synthesis started with the Pictet-Spengler reaction of histamine and naphthalene-2-carbaldehyde to a tetrahydropyridine intermediate, which was dehydrogenated with activated manganese (IV) oxide to LysoGlow84. Structure and purity of the synthesized LysoGlow84 were confirmed by NMR spectroscopy and mass spectrometry. The fluorescence intensity emitted by LysoGlow84 depended strongly on the pH of the solvent with highest fluorescence intensity recorded at pH 4. The fluorescence maximum (at 315 nm excitation) was observed at 440 nm. Biocompatibility of LysoGlow84 was investigated using cultured rat brain astrocytes and the marine flatworm Macrostomum lignano. Exposure of the astrocytes for up to 6 h to micromolar concentrations of LysoGlow84 did not compromise cell viability, as demonstrated by several viability assays, but revealed a promising property of this compound for staining of cellular vesicles. Conventional fluorescence microscopy as well as confocal scanning microscopy of LysoGlow84-treated astrocytes revealed co-localization of LysoGlow84 fluorescence with that of LysoTracker^® Red DND-99. LysoGlow84 stained unclear structures in Macrostomum lignano, which were identified as lysosomes by co-staining with LysoTracker. Strong fluorescence staining by LysoGlow84 was further observed around the worms’ anterior gut and the female genital pore which were not counterstained by LysoTracker Red. Thus, LysoGlow84 is a new promising dye that stains lysosomes and other acidic compartments in cultured cells and in worms.     

Cytotoxic Effects of Tropodithietic Acid on Mammalian Clonal Cell Lines of Neuronal and Glial Origin

The marine metabolite tropodithietic acid (TDA), produced by several Roseobacter clade bacteria, is known for its broad antimicrobial activity. TDA is of interest not only as a probiotic in aquaculture, but also because it might be of use as an antibacterial agent in non-marine or non-aquatic environments, and thus the potentially cytotoxic influences on eukaryotic cells need to be evaluated. The present study was undertaken to investigate its effects on cells of the mammalian nervous system, i.e., neuronal N2a cells and OLN-93 cells as model systems for nerve cells and glia. The data show that in both cell lines TDA exerted morphological changes and cytotoxic effects at a concentration of 0.3–0.5 µg/mL (1.4–2.4 µM). Furthermore, TDA caused a breakdown of the mitochondrial membrane potential, the activation of extracellular signal-regulated kinases ERK1/2, and the induction of the small heat shock protein HSP32/HO-1, which is considered as a sensor of oxidative stress. The cytotoxic effects were accompanied by an increase in intracellular Ca²⁺-levels, the disturbance of the microtubule network, and the reorganization of the microfilament system. Hence, mammalian cells are a sensitive target for the action of TDA and react by the activation of a stress response resulting in cell death.