Microbial indicators for sawdust and bark compost stability and humification processes

To what extent some microbial index ratios are suitable for use as early criteria for the level of compost stability during aerobic composting of coniferous sawdust and bark at mesophilic conditions was studied. Evolution of the specific respiration activity (CO₂-C/biomass C) and the ratios between some groups of microorganisms were followed as a function of composting time. The specific respiration activity was found to be an early and most reliable indicator of compost stability. The peroxidase and polyphenoloxidase enzyme activity during composting, as well as the composition of newly-formed humus substances were studied. The duration of composting increased the quality of newly-formed humus substances (C_h.a.:C_f.a ratio; Ca-complexed humic acid and resistance of organo-mineral complexes). The quality of humus substances could be used to assess compost stability. However, the results can be applied only under defined conditions.     

Evaluation of city refuse compost maturity: a review

Evaluation of the maturity of domestic refuse compost has been widely recognized as one of the most important problems concerning the composting process and the application of this product to the land. This has given rise, in recent years, to a great amount of information in the literature. Arranging and clarifying this information is the fundamental aim of the present paper. In the first place, the effects of insufficiently-matured compost on the soil-plant system are studied, and the criteria and methods proposed for the determination of compost maturity are described. The conditions or characteristics which the compost must meet to assure an acceptable degree of maturity are also established. Numerous studies make clear that the most notable effect of immature compost is the biological blockage of soil-available nitrogen which may give rise to serious N-deficiencies in crops with consequent depressive effects. The rapid decomposition of an immature compost may cause a decrease of the O₂-concentration and soil Eh and as a result, the creation of an anaerobic and strongly-reducing environment at the level of the root system. This causes an increase of the solubility of heavy metals in the soil and inhibition of plant seed germination by the production of phytotoxic substances, fundamentally ammonia, ethylene oxide and organic acids. The plant reacts to the inhibitory environment conditions by lowering its metabolic rate, reducing root respiration, decreasing nutrient absorption and slowing the gibberellin and cytokinin synthesis and transport. Many criteria or methods have been proposed to establish the degree of maturity and avoid these risks. They may be grouped into five types. Physical tests: temperature, odour and colour. Study of microbial activity parameters: measuring metabolic activity, biomass count and the study of the easily-biodegradable constituents. These include: respirometric studies, ATP and hydrolytic enzyme activity determinations, hydrolysable polysaccharide content, relation between total organic carbon and soluble glucides, and ratio of carbon in reducing sugars to total carbon. Study of humified organic matter: determining the richness in total humus and the degree of polymerization of humic compounds by means of paper chromatography and photocolorimetric methods. Chemical methods: C/N ratio in solid phase and in water extracts, pH, cation-exchange capacity and tests for ammonia, hydrogen sulphide, nitrates and nitrites. Biological methods: based on the determination of the germination index of seeds incubated in water extracts of the compost.     

Raman spectroscopy as a diagnostic tool for monitoring acute nephritis

Both acute nephritis and chronic nephritis account for substantial morbidity and mortality worldwide, partly due to the lack of reliable tools for detecting disease early and monitoring its progression non‐invasively. In this work, Raman spectroscopy coupled with multivariate analysis are employed for the first time to study the accelerated progression of nephritis in anti‐GBM mouse model. Preliminary results show up to 98% discriminant accuracy for the severe and midly diseased and the healthy among two strains of mice with different susceptibility to acute glomerulonephritis. This technique has the potential for non‐invasive or minimally‐invasive early diagnosis, prognosis, and monitoring of renal disease progression.

     

Fourier-transform infrared spectroscopy: a pharmacotoxicologic tool for in vivo monitoring radical aggression

Among the physico-chemical methods that can be used to investigate induced peroxidation in living cells, Fourier transform infrared (FT-IR) spectroscopy appears to be a valuable technique as it is non-destructive and sensitive for monitoring changes in the vibrational spectra of samples. We examined microsomal fractions from rat liver and brain by FT-IR to study the effect of radical aggression induced in vivo by carbon tetrachloride (CCl4). The length of the acyl chains was increased as a consequence of peroxidation induced by the xenobiotic. Moreover, an enhanced level of cholesterol esters and an increase in phospholipids were observed in the liver and the brain, respectively. The conformational structure of the membrane proteins was changed in both the liver and the brain. In the polysaccharide region, we observed an important loss in glucidic structures, such as a decrease in liver glycogen and in some brain glycolipids. These alterations are probably due to the interactions between cells and CCl4 and the metabolic changes caused by CCl4. Thus, FT-IR spectroscopy appears to be an useful tool and an accurate means for rapidly investigating the in vivo biochemical alterations induced by CCl4 in microsomes, and for correlating them with biochemical and physiological data.     

Magnetic resonance spectroscopy: an in vivo tool for monitoring cerebral injury in SIV-infected macaques

The purpose of our study was to demonstrate the feasibility of using in vivo proton Magnetic Resonance Spectroscopy (MRS) to monitor the brain manifestations of SIV infection in the macaque model of AIDS. Previous spectroscopy work on macaque brain tissue and in vivo work in humans is reviewed to provide the motivation and context for this study. We collected 34 MRS data sets on 14 uninfected rhesus macaques. From this data, we demonstrate that we are capable of detecting changes similar to those observed in human MRS studies for most metabolites using less than 10 animals. The juvenile macaques utilized in this study demonstrate age-related changes in the levels of N-acetyl aspartate (NAA), a neuronal marker. The quantity and distribution of neurochemicals in the macaque are found to be slightly, but significantly, different than in the human.     

Comparison between UV spectroscopy and Nirs to assess humification process during sewage sludge and green wastes co-composting

The humification of organic matter during composting was studied by the quantification and monitoring of the evolution of humic substances (Humic Acid-HA and Fulvic Acid-FA) by UV spectra deconvolution (UVSD) and near-infrared reflectance spectroscopy (NIRS) methods. The final aim of this work was to compare UVSD to NIRS method, already applied on the same compost samples in previous studies. Finally, UVSD predictions were good for HA and HA/FA (r² of 0.828 and 0.531) but very bad for FA (r² of 0.092). In contrary, all NIRS correlations were accurate and significant with r² of 0.817, 0.806 and 0.864 for HA, FA and HA/FA ratio respectively. From these results, HA/FA ratio being a well-used index of compost maturity, UVSD and NIRS represent two invaluable tools for the monitoring of the composting process. However, we can note that NIRS predictions were more accurate than UVSD calibrations.     

Satellite imagery as a tool for monitoring species diversity: an assessment

1. A landscape of 5 × 5·5 km in the Karnataka region of the Western Ghats of India was mapped into seven landscape element types, using field identification of types as well as supervised and unsupervised classification of satellite imagery.
2. Plant communities distributed in these landscape element types were surveyed in the field using 246 quadrats of 10 × 10 m, in order to assess whether these types could be distinguished in terms of species composition. All angiosperms excluding grasses, which could not be identified accurately in the field, were recorded for this purpose.
3. Landscape element types identified in the field harboured significantly distinctive sets of species of flowering plants, and were also by and large distinctive in terms of their species richness.
4. Landscape element types could be identified accurately on the basis of supervised classification: the types thus demarcated harboured distinctive sets of flowering plants.
5. Landscape element types coupled to satellite imagery could then be used to organize a programme of monitoring biodiversity.
6. Unsupervised classification of satellite imagery did not permit classification of landscape element types with a high enough level of accuracy. In consequence, the demarcated landscape element types did not harbour significantly distinctive sets of species of flowering plants. Unsupervised classification is therefore not appropriate in a programme of monitoring biodiversity.     

Effect of matured compost as a bulking and inoculating agent on the microbial community and maturity of cattle manure compost

Cattle manure composts were consecutively manufactured. Compost that reached maturity first was used as a bulking and inoculating agent for subsequent compost production. The microbial community was measured through phospholipid fatty acid analysis. Changes in the content of fatty acid methyl esters derived from phospholipids were similar in all the composts. The diversity index for the fatty acid methyl ester content increased in the secondary-produced compost from the onset of composting. Microbial succession was accelerated using matured compost. The proportion of biomarker fatty acids for gram-positive bacteria also increased in the secondary-produced compost from the early stage of composting. Changes in germination index indicated the maturity stage of the compost. The proportion of biomarker fatty acids for gram-positive bacteria was positively correlated to the germination index, indicating that phospholipid fatty acid analysis is an indicator for evaluating the maturity of cattle manure composts.     

Gastrointestinal ischemia monitoring through impedance spectroscopy as a tool for the management of the critically ill

Impedance spectroscopy (IS) has been proposed as a tool for monitoring mucosal tissue ischemia and damage in the gut of critically ill patients resulting from shock and hypoperfusion. A specific device and system have been developed and tested for this specific application over the past 12 years by our research group. This paper reviews previously published studies as well as unpublished experimental results, and puts the whole in context and perspective to help understand this technology. Results presented include summaries of gastric reactance measurement understanding, in vivo measurements in animal models, clinical significance of the measurement, and future perspectives of clinical use of this technology. All of the experimental work done to date has been designed to determine the evolving device prototypes’ performance and limitations from an instrumentation point of view. Although there are still questions to be answered with regard to the IS measurement, we conclude that we have reached enough confidence in the measurement and the device’s performance and safety to begin clinically oriented research to learn how this technology may be useful in the diagnosis and management of different populations of the critically ill.     

Use of Raman spectroscopy as a tool for in situ monitoring of microwave-promoted reactions

The progress of microwave-promoted reactions can be monitored by interfacing a Raman spectrometer with a scientific microwave unit. The apparatus is assembled from commercially available components. It is used in this protocol to follow the base-catalyzed reaction of salicylaldehyde with ethylacetoacetate to yield 3-acetylcoumarin. It is possible to watch the reaction spectroscopically in real time, determine when it reaches completion and thus use it as a tool for rapid reaction optimization.     

The B-value: a tool for monitoring data

This paper considers the problem of monitoring slowly accruing data from a nonsequentially designed experiment. We describe the use of the B-value, which is a transformed Z-value, for the calculation of conditional power. In data monitoring, interim Z-values do not allow simple projections to the end of the study. Moreover, because of their popular association with P-values, Z-values are often misinterpreted. If observed trends are viewed as the realization of a Brownian motion process, the B-value and its decomposition allow simple extrapolations to the end of the study under a variety of hypotheses. Applications are presented to one- and two-sample Z-tests, the two-sample Wilcoxon rank sum test, and the log-rank test.     

Fluorescence spectroscopy as a tool for monitoring solubility and aggregation behavior of beta-lactoglobulin after heat treatment

Denaturation and aggregation of whey proteins are of interest to the food and pharmaceutical industry due to the importance of final structure in functionality, impact on food texture, and the chemical stability of the final product. In this study, we demonstrate the potential of fluorescence spectrometry combined with multivariate chemometric methods for quantifying solubility and aggregation behavior of beta-lactoglobulin (beta-LG); a major whey protein and a frequent food ingredient. Heat-induced aggregation of beta-LG was studied under different conditions including pH, temperature and heating durations. Results showed very good agreement between the fluorescence-based predictions and measurements obtained by HPLC and gravimetric analysis regardless of the conditions. Standard normal variate (SNV), a signal preprocessing and filtering tool, was found to enhance the predictive accuracy and robustness of the fluorescence-based model.     

Novel tool for characterization of noncrystalline regions in cellulose: a FTIR deuteration monitoring and generalized two-dimensional correlation spectroscopy

Our previous results indicated that noncrystalline regions in a regenerated cellulose film comprised at least three domains engaged in different manners of molecular assembly [Kondo et al. In Cellulose Derivatives; Heinze, T. J., Glasser, W. G., Eds.; ACS Symposium Series 688; American Chemical Society: Washington, DC, 1998; Chapter 12]. In this article, we attempt to characterize each of the three noncrystalline domains in the film. The method used was a FTIR monitoring of deuteration from hydroxyl (OH) groups to OD, leading to the two-dimensional (2D) correlation analysis. The time-scan spectra in the OH-OD exchanging reaction were transformed into two kinds of 2D correlation spectra, the synchronous and the asynchronous spectra. Of the two, some cross-peaks were found in the latter spectrum. This suggests that the asynchronous 2D correlation spectrum could differentiate the contribution of OH groups due to different frequencies of hydrogen bonds in each domain. Here we will show the validity of this 2D correlation method as a powerful tool to predict hydrogen-bonding networks of the noncrystalline domains in cellulose.     

Distribution models for the amphibian chytrid Batrachochytrium dendrobatidis in Costa Rica: proposing climatic refuges as a conservation tool

Aim We use novel data on the occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in Costa Rica to model its potential distribution in that country. Location Lowland and montane areas of Costa Rica. Methods We use published and new data on the presence of B. dendrobatidis on 647 amphibians (35 species). Screening was performed through histological techniques by which 156 sites were surveyed. Of these, 21 were found to have the amphibian chytrid. Maxent, a presence‐only distribution modelling technique, was used to create 100 predictions of B. dendrobatidis occurrence, of which the most accurate 10 (based on area under the receiver‐operating characteristic curve) were chosen to create a composite distribution model. This approach increased confidence in model predictions, distinguishing areas of high probability of occurrence and low variability across model runs (higher confidence) from those with high probability but high variability (lower confidence). Results Predicted distribution patterns were not uniform along Costa Rica's mountains, where most amphibian declines have occurred. The pathogen was predicted to occur with greater probability on the Caribbean slopes than on the Pacific slopes. While high temperature seems to constrain the distribution of the pathogen, areas that also have small amounts of rainfall during the driest period of the year were predicted to have low probability of B. dendrobatidis occurrence. Main conclusions The model predicts that the Santa Elena Peninsula and the Central Valley have low probabilities of B. dendrobatidis occurrence, suggesting that they could function as refuges for amphibians. In such refugial areas, one could expect B. dendrobatidis to be absent, or to be present in low abundance (rendering an epidemic outbreak of chytridiomycosis unlikely). Craugastor ranoides, which belongs to a group of frogs particularly sensitive to chytridiomycosis outbreaks, persists in the hot and seasonally dry Santa Elena Peninsula but disappeared in the nearby colder and more humid Guanacaste Volcanic Chain. This information suggests that climatic refuges, where environmental conditions prevent disease outbreaks, could be an important component in amphibian conservation.     

Stability and maturity of a green waste and biowaste compost assessed on the basis of a molecular study using spectroscopy,thermal analysis,thermodesorption and thermochemolysis

The organic matter (OM) of a green waste and bio waste compost was characterised over 8 months and the observed evolution was correlated with physico-chemical parameters (temperature, pH, carbon content, C/N ratio). Thermochemolysis and thermodesorption were used to monitor bacterial activity (stability) whereas diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) and thermodifferential analysis (TDA) permitted to determine the degree of OM humification (maturity). DRIFT spectroscopy and TDA provide two indicators of maturity since, with these two techniques, the signals associated with the biodegradable organic matter decrease relatively to the signals associated with refractory organic matter. This increase in R_TG and R_IR ratios between aromatic to aliphatic signals constitutes a proof for OM complexification. It correlates with humic acids/fulvic acids ratio known to be a maturity index.     

有机固体废弃物堆肥的物质变化及腐熟度评价

堆肥是资源化处理有机固体废弃物的有效途径之一．有机固体废弃物的种类繁多,物科的性质差异很大,另外,由于堆肥条件的不同,也会引起堆肥的物质变化有很大差异．堆肥的稳定度和腐熟度是衡量堆肥产品质量的尺度,其评价对于安全农用有着重要意义．稳定度则重于堆肥施用对周围环境的影响,而腐熟度则重于堆肥施用对植物生长的影响,它们受堆肥物料,堆肥条件等诸多因素的综合影响,其评价指标因而多种多样．堆肥稳定度主要从堆肥的温度、颜色、CO2是最为简便的稳定度评价指标,当其趋于环境温度时,表明堆肥达到稳定．堆肥腐熟度的评价指标很多,包括化学指标、生物活性指标以及植物毒性指标3类,其中种子发芽系数作为植物毒性指标被认为是最可靠的评价指标之一。     

Surface plasmon resonance spectroscopy: an emerging tool for the study of peptide-membrane interactions

The interactions between peptides and membranes mediate a wide variety of biological processes, and characterization of the molecular details of these interactions is central to our understanding of cellular events such as protein trafficking, cellular signaling and ion-channel formation. A wide variety of biophysical techniques have been combined with the use of model membrane systems to study peptide-membrane interactions, and have provided important information on the relationship between membrane-active peptide structure and their biological function. However, what has generally not been reported is a detailed analysis of the affinity of peptide for different membrane systems, which has largely been due to the difficulty in obtaining this information. To address this issue, surface plasmon resonance (SPR) spectroscopy has recently been applied to the study of biomembrane-based systems using both planar mono- or bilayers or liposomes. This article provides an overview of these recent applications that demonstrate the potential of SPR to enhance our molecular understanding of membrane-mediated peptide function.     

Diffuse reflectance spectroscopy as a monitoring tool for gastric mucosal devitalization treatments with argon plasma coagulation

Electrosurgery with argon plasma coagulation is a widespread technique used in various medical fields for applications which range from hemostasis to devitalization processes. Developing tools which provide feedback concerning tissue condition during these surgeries is fundamental for improving the safety and success of this treatment. We present here a method based on diffuse reflectance spectroscopy to monitor gastric mucosal devitalization treatments. The analysis of the diffusely reflected spectra of the tissue allows us to differentiate between ablation states by using linear discriminant analysis (LDA) as a classification algorithm. An ex vivo pilot study on several swine stomachs showed promising results, with 97.8% of correctly classified ablation states on a new unseen stomach, encouraging further tests with human tissue.     

Composting of animal manures and chemical criteria for compost maturity assessment. A review

New livestock production systems, based on intensification in large farms, produce huge amount of manures and slurries without enough agricultural land for their direct application as fertilisers. Composting is increasingly considered a good way for recycling the surplus of manure as a stabilised and sanitised end-product for agriculture, and much research work has been carried out in the last decade. However, high quality compost should be produced to overcome the cost of composting.     

FTIR and UV spectroscopy in real-time monitoring of S. cerevisiae cell culture

A combination of FTIR and UV spectroscopy is proposed as a novel technique for integrated real-time monitoring of metabolic activity and growth rates of cell cultures, required for systematic studies of cellular low-frequency (LF) electric and magnetic field (EMF) effects. As an example, we investigated simultaneous influence of periodic LF 3D EMFs on a culture of Saccharomyces cerevisiae (baker's yeast) cells. Amplitudes, frequencies and phases of the field components were the variable parameters. Electromagnetic fields were found to efficiently control the activity of the yeast cells, with the resulting CO₂ production rates, as monitored by FTIR spectroscopy, varying by at least one order of magnitude due to the field action. Additionally, population dynamics of the yeast cells was monitored by UV absorption of the yeast culture at λ_prob = 320 nm, and compared to the CO₂ production rates. The detected physiologically active frequencies are all below 1 kHz, namely, 800 Hz excitation was effective in reducing the metabolic rates and arresting cell proliferation, whereas 200 Hz excitation was active in accelerating both cell proliferation and overall metabolic rates. The proposed methods produce objective, reliable and quantitative real-time results within minutes and may be used in various tasks that could benefit from a rapid feedback they provide in the form of metabolic and growth rates. Amplitude and frequency dependences of the LF EMF effects from individual field components with different polarizations were recorded and qualitatively interpreted based on a simple model, describing ion diffusion through a membrane channel.