483 research outputs found

    Dynamics of gas formation during ensilage

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    The formation of a whole spectrum of gasses, which is undesirable occurs during ensiling process. The formation of gasses is undesirable, because it is often a sign of undesirable processes in silages, and causes concern about the impact on the global environment. Formation of CO2 is the most abundant. Besides CO2, the formation of toxic N oxides also occurs during ensiling. Since silage additive addition affects the fermentation pattern, the aim of the study was to monitor the formation of various gasses from silages treated with different silage additives. A grass ley (70% timothy) was harvested on August 24th 2013, nearby Helsingborg. Bacterial inoculant (E. faecium, L. plantarum, L. buchneri) at the rate of 250000 cfu/g FF, and silage additive Safesil at the rate of 3 L/ton FF were compared with untreated control. Gasses collected in bags were analysed for N2, H2, O2, CO, CH4 by gas chromatographaphy. CO2, NO, and NO2 were absorbed in water and analysed using ion chromatography. Standard analyses to determine silage quality were performed after ensiling period. Silages treated with bacterial inoculant had significantly higher pH, propionic acid, acetic acid, and ethanol contents but lower concentration of lactic acid than other silage treatments. Control and bacterially inoculated silages produced more gas than Safesil treated silages, mainly due to an increased proportion of CO2. The formation of NOx gases displayed no significant differences among other treatments

    Narratives of Change: Identity and Recognition Dynamics in the Process of Moving Away From a Life Dominated by Drug Use

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    The concepts of identity and recovery capital are recognized as being an embedded part of moving away from a life dominated by drug use. However, the link between these two concepts and the effect of broader social structures, and the normative assumptions underpinning the condition of recovery, is less explored. This article focuses on the social practices of everyday life in the foreground of identity formation, meaning that “who I am” is an inseparable part of “what I do.” A narrative approach was employed to analyze qualitative follow-up data extracted from 48 in-depth interviews with 17 males and females with drug-using experience that were conducted posttreatment on three separate occasions over a period of 2.5 years. Theories of identity formation were employed to analyze the interdependent dynamic between social structure, persona and social resources, and way of life and identity. The analyses identified four narratives related to how people present themselves through the process of changing practices. Following the work of Honneth, we argue that the positive identity formation revealed in these narratives is best understood as a struggle for recognition via the principle of achievement. However, the participants’ self-narratives reflected cultural stories—specified as formula stories—of “normality,” “addiction,” and the “addict,” which work into the concepts of self and confine options of storying experiences during the recovery process. This study demonstrate that the process of recovery is culturally embedded and constitutes a process of adaption to conventional social positions and roles. We suggest challenging dominant discourses related to “addiction as a disease” and “normality” in order to prevent stigma related to drug use and recovery. In so doing, it may contribute to broaden conditions for identity (trans)formation for people in recovery.publishedVersio

    Toxicological evaluation of complex mixtures by pattern recognition: Correlating chemical fingerprints to mutagenicity

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    We describe the use of pattern recognition and multivariate regression in the assessment of complex mixtures by correlating chemical fingerprints to the mutagenicity of the mixtures. Mixtures were 20 organic extracts of exhaust particles, each containing 102-170 individual compounds such as polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs, oxy-PAHs, and saturated hydrocarbons. Mixtures were characterized by full-scan GC-MS (gas chromatography-mass spectrometry). Data were resolved into peaks and spectra for individual compounds by an automated curve resolution procedure. Resolved chromatograms were integrated, resulting in a predictor matrix that was used as input to a principal component analysis to evaluate similarities between mixtures (i.e., classification). Furthermore, partial least-squares projections to latent structures were used to correlate the GC-MS data to mutagenicity, as measured in the Ames Salmonella assay (i.e., calibration). The best model (high r2 and Q2) identifies the variables that co-vary with the observed mutagenicity. These variables may subsequently be identified in more detail. Furthermore, the regression model can be used to predict mutagenicity from GC-MS chromatograms of other organic extracts. We emphasize that both chemical fingerprints as well as detailed data on composition can be used in pattern recognition.publishedVersio

    The effect of nitrate content in forage on quality of silage fermentation

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    Nitrate content in fresh herbage is one of the factors affecting fermentation in silage. Hein (1970) observed that ensiling of forages with low nitrate content often results in silages with high butyric acid contents. Butyric acid is an undesirable product of clostridia in silages indicating low silage nutritional quality (Pahlow et al., 2003). The effect of nitrate on butyric acid formation is derived from its degradation products. Nitrate undergoes reduction to nitrite which can be further converted to nitric oxide which is considered to be toxic for clostridia (Spoelstra, 1983). Therefore, crops high in nitrate decreases clostridial activity and, hence, butyric acid formation. The effect of nitrate content in fresh crops on butyric acid formation was summarized by Weissbach (1996). The summary shows high occurrence (78%) of butyric acid in silages made from crops low (1 g NO3 per kg DM was only 26%. Since it is common to use silage additives to improve or secure a proper ensiling process, it is interesting to study how different nitrate contents in fresh crops influence efficiency of silage additives. The objective of the study was, therefore, to study the effect of nitrite containing silage additives on silage quality with crops differing in nitrate content

    Evaluation of Electrosorption Process for Phosphate and Nitrate Removal from Wastewater

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    The present work is dedicated to the preparation and characterization of carbon-based electrodes for the removal of phosphates and nitrate ions from wastewater by CDI method. Carbons obtained from the pyrolysis were used to prepare electrodes and these electrodes were characterized using a number of experimental techniques. Based on the experimental results, the electrodes showed a strong affinity towards the nitrates than phosphates. This was evident from the kinetic constants and significantly higher capacity of electrosorption. At 1mM solutions, representative of a typical wastewater, nitrate exhibited about 3.5 times higher concentration than phosphates on a molar basis. The electrodes were reasonably stable under low concentrations of nitrates. At higher concentrations, the electrodes were not completely regenerable when the desorption step was carried out at 0V. These results are covered in this manuscript.publishedVersio

    CSF circulation and dispersion yield rapid clearance from intracranial compartments

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    In this paper, we used a computational model to estimate the clearance of a tracer driven by the circulation of cerebrospinal fluid (CSF) produced in the choroid plexus (CP) located within the lateral ventricles. CSF was assumed to exit the subarachnoid space (SAS) via different outflow routes such as the parasagittal dura, cribriform plate, and/or meningeal lymphatics. We also modelled a reverse case where fluid was produced within the spinal canal and absorbed in the choroid plexus in line with observations on certain iNPH patients. No directional interstitial fluid flow was assumed within the brain parenchyma. Tracers were injected into the foramen magnum. The models demonstrate that convection in the subarachnoid space yields rapid clearance from both the SAS and the brain interstitial fluid and can speed up intracranial clearance from years, as would be the case for purely diffusive transport, to days.publishedVersio

    WIND-PVPA: Water/Ion NMR Detected PVPA to assess lipid barrier integrity in vitro through quantification of passive water- and ion transport

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    Water/Ion NMR Detected – Phospholipid Vesicle Permeability Assay (WIND-PVPA), is presented as a novel, straightforward and automatable method to assess lipid barrier integrity in vitro. The apparent permeability constants of water- and ions across the PVPA barriers are determined in a one-pot experiment under the influence of membrane-active guest molecules. NMR spectroscopy is used to quantify the water directly (D2O) and the ions indirectly (complexed with EDTA) as a function of time. WIND-PVPA is demonstrated using four anti-microbial peptides, to show that membrane active molecules can be differentiated by their disruptive influence on the PVPA system. The results obtained are compared with explicit molecular dynamics simulations of lipid bilayers, AMPs, water and salt, where the motions of all individual water molecules relative to the lipid bilayer are monitored over the course of the simulations, allowing the calculation of theoretical apparent permeability constants of the corresponding single bilayer systems. Proof-of-principle is presented that WIND-PVPA can be used to evaluate the lipid barrier destabilizing effect of active guest molecules by measuring changes in passive water- and ion permeabilities upon exposure. The method is highly flexible in terms of barrier composition, choice of probes and membrane active compounds
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