Bacterial mobilization and transport through manure enriched soils: Experiment and modeling.

A precise evaluation of bacteria transport and mathematical investigations are useful for best management practices in agroecosystems. In this study, using laboratory experiments and modeling approaches, we assess the transport of bacteria released from three types of manure (cow, sheep, and poultry) to find the importance of the common manures in agricultural activities in soil and water pollution. Thirty six intact soil columns with different textures (sandy, loamy, and silty clay loam) were sampled. Fecal coliform leaching from layers of the manures on the soil surface was conducted under steady-state saturated flow conditions at 20 °C for up to four Pore Volumes (PVs). Separate leaching experiments were conducted to obtain the initial concentrations of bacteria released from the manures (Co). Influent (Co) and effluent (C) bacteria concentrations were measured by the plate-count method and the normalized concentrations (C/C0) were plotted versus PV representing the breakthrough curves (BTCs). Transport parameters were predicted using the attachment/detachment model (two-kinetic site) in HYDRUS-1D. Simulations fitted well the experimental data (R2 = 0.50-0.96). The attachment, detachment, and straining coefficients of bacteria were more influenced by the soils treated with cow manure compared to the sheep and poultry manures. Influent curves of fecal coliforms from the manures (leached without soil) illustrated that the poultry manure had the highest potential to pollute the effluent water from the soils in term of concentration, but the BTCs and simulated data related to the treated soils illustrated that the physical shape of cow manure was more important to both straining and detachment of bacteria back into the soil solution. Detachment trends of bacteria were observed through loam and silty clay loam soils treated with cow manure compared to the cow manure enriched sandy soil. We conclude that management strategies must specifically minimize the effect of fecal coliform concentrations before field application, especially for the combination of poultry and cow manures, which has higher solubility and tailing behavior, respectively. Interestingly, the addition of sheep manure with all three soils had the lowest mobilization of bacteria. We also suggest studying the chemistry of soil solution affected by manures to present all relevant information which affect bacterial movement through soils during leaching.

[Wood transformation in dead-standing trees in the forest-tundra of Central Siberia].

Changes in the composition of wood organic matter in dead-standing spruce and larch trees depending on the period after their death have been studied in the north of Central Siberia. The period after tree death has been estimated by means of cross-dating. The results show that changes in the composition of wood organic matter in 63% of cases are contingent on tree species. Wood decomposition in dead-standing trees is accompanied by an increase in the contents of alkali-soluble organic compounds. Lignin oxidation in larch begins approximately 80 years after tree death, whereas its transformation in spruce begins not earlier than after 100 years. In the forest-tundra of Central Siberia, the rate of wood organic matter transformation in dead-standing trees is one to two orders of magnitude lower than in fallen wood, which accounts for their role as a long-term store of carbon and mineral elements in these ecosystems.

Changes in the chemical composition of water-extractable organic matter during composting: distribution between stable and labile organic matter pools.

Aerobic decomposition and stabilization of organic matter during the composting of waste materials is primarily due to the biochemical transformation of water-soluble compounds in the liquid phase by the microbial biomass. For this reason water-soluble organic matter represents the most active fraction of compost, both biologically and chemically, and thus should directly reflect the biochemical alteration of organic matter. This work aims to elucidate the microbial-mediated processes responsible for the distribution of soluble organic matter between stable and labile pools with composting time. Accordingly, chemical analysis as well as UV absorption, and 1H and 13C-NMR spectroscopy of samples collected during the industrial composting of urban waste revealed microbial induced transformation of water-extractable organic matter over time. The chemical composition changed from labile, hydrophilic, plant-derived organic compounds in the beginning to predominately stable, hydrophobic moieties comprising lignin-derived phenols and microbially-derived carbohydrates at later stages of composting.

External surface structure of organoclays analyzed by transmission electron microscopy and X-ray photoelectron spectroscopy in combination with molecular dynamics simulations.

HYPOTHESIS: Interface properties of organoclay particles can be related directly to type of organic cation, and density and arrangement of organic coating at clay surfaces. EXPERIMENTS: This study provides detailed nanoscale insights on surface structure of hexadecyltrimethylammonium/hexadecylpyridinium-montmorillonite (HDTMA(+)/HDPy(+)-M) organoclays by combining several experimental methods (e.g. transmission electron microscopy, TEM, and X-ray photoelectron spectroscopy, XPS) with molecular simulations. FINDINGS: TEM showed a relation between the thickness of the organic coating and the amount of organic cation loading. Furthermore, coating thickness varied for the same sample indicating a heterogeneous surface of clay particles. The changes in elemental composition determined by XPS were correlated with the thickness of the organic coating. High resolution XPS showed changes in binding energies of CN bonds, which were attributed to varying local environment of head groups of organic cations. Classical molecular dynamics (MD) simulations showed a successive transformation of the organic cation coating of the montmorillonite surface from thin disordered monolayers at low up to disordered bilayer or quasi paraffin-type arrangements at high surfactant coverages. For organoclays with low cation loading no significant difference was observed between HDTMA(+) and HDPy(+). However, at high cation loading, surface packing density was higher for HDTMA(+) than for HDPy(+).

[Coping with anger and the premenstrual syndrome]. / Argerbewältigung und prämenstruelles Syndrom.

OBJECTIVE: Investigations in recent years confirm the importance of "anger coping-behaviour" for women suffering from different diseases such as migraine, high blood pressure and coronary heart disease. The hypothesis for this investigation was that "anger-in" coping (anger-suppression) is a possible causal factor in the premenstrual syndrome. METHODS: Data analysis was undertaken on 38 patients (average age 32 years) fulfilling the inclusion criteria. The Menstrual Distress Questionnaire (MDQ) was used for measuring the intensity of premenstrual symptoms. As a result of a cluster analysis of MDQ scores, the 38 patients were divided into 3 subgroups (group 1: mild symptoms, n = 16; group 2: moderate symptoms, n = 10; groups 3: severe symptoms, n = 12). The 3 groups were compared by using different questionnaires regarding the variables anger, attitudes to menarche and menstrual bleeding, anxiety and depression. Additionally, sociodemographic data were obtained and a daily record taken for 2 days premenstrually and 5 day postmenstrually of subjective replies to a standardized protocol. RESULTS: Contrary to our expectations the results showed no significant differences for "anger coping" between the 3 subgroups. Increased daily stress (professional and familial double load) statistically significantly influenced the intensity of premenstrual symptoms. Additional significant factors were a general tendency towards somatization disorder, a negative attitude toward menarche and menstrual bleeding, as well as a tendency to depressive mood in patients with severe premenstrual symptoms. CONCLUSION: Emotional disorders (anger, anxiety) showed less influence on the premenstrual syndrome in the investigated women than daily stress and medical anamnesis.

Polycyclic aromatic hydrocarbons (PAH) in different forest humus types.

The behavior of 20 PAH in the organic layers of a L mull, an Of mull and a mor was assessed by a combined approach of a soil profile study, and the analysis of particle-size separates. Increasing PAH concentrations with depth in the mor profile (L, 866 µg kg(-3); Of, 2902 µg kg(-1); Oh, 10489 ug kg(-1)) were assigned to selective enrichment during organic matter decomposition. PAH were further highly enriched within the finer separates. For the L horizons, significant positive correlations were established between the enrichment of individual PAH (as observed from the decomposition gradient between the >2-mm fraction and the < 0.05-mm fraction), and the KOW for each compound. The slope of the regression line, m, described the degree of differentiation between low- and high-molecular PAH during litter decomposition. Since m was greatest in the most biologically active humus type (L mull, 0.33) and smallest in the most inactive (mor, 0.20), microbial breakdown was assumed as the dominating process for this differentiation. The results also indicated that decomposition processes had already taken place in the L horizons, leading to morphological and chemical changes of organic matter, and to an enrichment of high molecular PAH.

[Pharmacoeconomic evaluation of pravastatin in the secondary prevention of coronary heart disease in patients with average cholesterol levels. An analysis for Germany based on the CARE study]. / Pharmakoökonomische Bewertung von Pravastatin in der Sekundärprävention der koronaren Herzkrankheit bei Patienten mit durchschnittlichen Cholesterinwerten. Eine Analyse für Deutschland auf der Grundlage der CARE-Studie.

Those people who are to decide about health care systems are increasingly forced to identify unnecessary costs and achieve savings in health care. Especially for diseases with high prevalence like illnesses of the heart and the circulatory system preventive measures are very important. This economic analysis tries to clarify whether the secondary-preventive application of the HMG-CoA reductase-inhibitor pravastatin is, apart from the clinical benefit, economically justified in patients suffering from coronary heart disease with average cholesterol levels. In the case of this study, the underlying type of economic evaluation was an incremental cost-effectiveness analysis. The outcome was defined as costs per life-year saved. This retrospective study is based on the results of the CARE (Cholesterol And Recurrent Events) study which has been published elsewhere [21]. When calculating costs we took into account the perspective of 3rd party payers (public health insurance) in Germany. The calculation of cost-effectiveness was carried out for the whole study population in CARE as well as for all patients aged 60 or more years in the CARE study. This was done because the different groups vary by the numbers of avoided myocardial infarctions, strokes and loss of life years. Netcosts for pravastatin therapy, i.e. drug costs for pravastatin minus costs for avoided events, were about 9.54 Mio DM (referring to 1,000 patients treated for a period of 5 years). Net-costs for patients aged 60 or more years were 8.18 Mio DM. The effectiveness was defined as the number of life years saved and amounted to 216 years of life saved (YOLS) in the overall study group. For patients aged 60 or more years we found that 358 years were saved. The costs per life years saved (i.e. the net-costs of pravastatin therapy divided through the number of life years saved) turned out to be 44,000 DM per person in the study group. For patients over 60 the costs were 23,000 DM. Lipid-lowering with pravastatin in the secondary prevention of coronary heart disease in Germany is cost-effective. In those patients aged 60 or more yeas the use of pravastatin is even more cost-effective than in all patients included in the CARE study.