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Selected AbstractsDehydration tolerance and water vapour absorption in two species of soil-dwelling Collembola by accumulation of sugars and polyolsFUNCTIONAL ECOLOGY, Issue 5 2001M. Holmstrup Summary 1,Physiological and biochemical responses to desiccation were studied in two species of hygrophilic Collembola, Folsomia fimetaria L. and Protaphorura armata Tullberg. The temporal changes in water content, body fluid osmotic pressure, and accumulation of sugars and polyols during desiccation stress, equivalent to severe soil drought are reported. 2,Both species initially lost about 50% of their initial content of osmotically active water. Within 7 days F. fimetaria had re-established their preliminary water content by absorbing water vapour from the atmosphere. Protaphorura armata also significantly increased their water content over the following 10 days. 3,Both species were able to resume their hyperosmotic status relative to the desiccating environment they were placed in. The accumulation of myo-inositol and two other unidentified compounds (F. fimetaria) and trehalose (P. armata) made an important contribution to this phenomenon. 4,These results suggest that water vapour absorption by accumulation of sugars and polyols may be widespread in soil-dwelling Collembola. [source] Degradation of TCE with Iron: The Role of Competing Chromate and Nitrate ReductionGROUND WATER, Issue 3 2000Oliver Schlicker This study evaluates the potential of using granular iron metal for the abiotic removal of the organic ground water pollutant trichloroethene (TCE) in the presence of the common inorganic co-contaminants chromate and nitrate, respectively. Our long-term column experiments indicate a competitive process between TCE dechlorination and reductive transformation of chromate and nitrate, which is reflected in a significantly delayed onset of TCE dechlorination. Delay times and therefore the ranges of the nonreactive flowpaths increased with increasing experimental duration, resulting in a migration of the contaminants through the iron metal treatment zone. The present investigation also indicates that the calculated migration rates of TCE and the added cocontaminants chromate and nitrate are linearly related to the initial content of the cocontaminants. With an average pore water velocity of 0.6 m/d and a surface area concentration of 0.55 m2/mL in the column, the calculated migration rates varled between 0.10 cm/d and 5.86 cm/d. The particular similarity between the values of TCE migration and the migration of the strong oxidants chromate and nitrate and the long-term steady state of the TCE dechlorination in the absence of the chromate and nitrate indicates that these competitive transformations are the driving force for the gradual passivation of the granular iron due to the buildup of an electrically insulating Fe(III)-oxyhydroxide. Based on these passivation processes, general formulae were developed that allow a simplified approximation of breakthrough times for the contaminants TCE, chromate, and nitrate. [source] Intervention with polyphenol-rich fruit juices results in an elevation of glutathione S -transferase P1 (hGSTP1) protein expression in human leucocytes of healthy volunteersMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 12 2006Thomas Hofmann Abstract Polyphenols are probably antigenotoxic on account of their antioxidant activities and might alter phase I and II enzymes in a way that results in chemoprotection. We investigated the hypothesis that polyphenols enhance expression of glutathione S -transferases (GSTs), which increases carcinogen detoxification and thereby provides protection against oxidative stress. HGSTP1 protein expression and GST polymorphisms were determined in leucocytes obtained during an intervention study with healthy subjects consuming two fruit juices in an 8 wk trial (polyphenol-free run in phase, juice intervention phase, washout phase, second juice intervention phase, each treatment regime lasted for 2 wk). The study had originally shown that juice intervention significantly reduced oxidative DNA damage in leucocytes at week 8 (Bub, A., Watzl, B., Blockhaus, M., Briviba, K. et al., J. Nutr. Biochem. 2003, 14, 90,98). We reanalysed the levels of DNA damage based on GST genotypes. We also treated leucocytes in vitro with mixtures of polyphenols and determined cytotoxicity and expression of 96 genes related to drug metabolism. Key results with leucocytes of the intervention study were that the initial content of hGSTP1 protein was first suppressed at weeks 4 and 6. At week 8, however, hGSTP1 protein expression was significantly increased. HGSTP1 protein levels and DNA damage were inversely correlated (p = 0.005), but there was no difference for cells obtained from subjects with hGSTM1*1 and hGSTM1*0 genotypes, nor was there any difference between cells from subjects consuming the two different juices. The treatment of leucocytes with polyphenol mixtures in vitro did not result in modulated GST gene expression or total GST activity, but in an up-regulation of other biotransformation enzymes (e. g., members of the cytochrom P450 and the sulphotransferase family). In conclusion, in vitro treatment of leucocytes led to a modulated mRNA expression of selected genes, not directly related to oxidative defence systems. In vivo, however, we observed a delayed enhancement of hGSTP1, which could be associated with an initial repression of oxidative DNA damage in leucocytes from human subjects, consuming juices with high levels of polyphenols. [source] Effect of package light transmittance on the vitamin content of milk, part 3: Fortified UHT low-fat milkPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2009Alexander Saffert Abstract This work is the third and last part of a milk study evaluating the effect of package light transmittance on the vitamin content of milk, in this case on fortified UHT low-fat milk. The milk was stored under light with an intensity of 700,lux in polyethylene terephthalate (PET) bottles with varying light transmittance to monitor the changes in the vitamin A, B2 and D3 contents over a storage period of 12 weeks at 23°C. Milk packed in pigmented PET bottles with the lowest light transmittance, which was stored in the dark under the same experimental conditions, served as the ,control' sample. In clear PET bottles, a reduction of 93% of the initial content was observed for vitamin A and 66% for vitamin D3, while the vitamin B2 content was completely degraded. In all pigmented PET bottles, the vitamin retention was only slightly higher; the losses ranged between 70 and 90% for vitamin A, between 63 and 95% for vitamin B2, and between 35 and 65% for vitamin D3 depending on the pigmentation level. In the dark-stored ,control' sample, a 16% loss could be observed for vitamin A, while the level of vitamins B2 and D3 remained almost stable. Copyright © 2008 John Wiley & Sons, Ltd. [source] Shelf life of vegetable oils bottled in different scavenging polyethyleneterephthalate (PET) containersPACKAGING TECHNOLOGY AND SCIENCE, Issue 5 2008R. Sacchi Abstract The shelf life of extra virgin olive oil (EVOO) and sunflower oil (SO) bottled in containers with different levels of oxygen scavenger (OS) and stored at room temperature under diffuse lighting conditions for 6 months has been evaluated. Four packaging materials were tested: glass, polyethyleneterephthalate (PET), PET including 1% of OS (PET 1%) and PET including 5% of OS (PET 5%). Free acidity, peroxide value (PV), spectrophotometric indices (K232, K270, ,K), antioxidant (biophenols and tocopherols) content, pigment (chlorophylls and carotenoids) change and the amount of oxygen dissolved in the oil were monitored during storage. A significant influence of the packaging material on the quality decay was not found. The differences in the shelf life observed between oils bottled in PET and oils bottled in glass are attributable to a difference in the initial content of dissolved oxygen in the oils. The study showed the usefulness of monitoring changes in dissolved oxygen level, antioxidant (phenols and tocopherols) and pigment (chlorophyll and carotenoids) profiles during oil storage. The change of these compounds could in fact supply important information on the oxidation processes that occur in bottled oils and on the effectiveness of the material employed in oil packaging. Copyright © 2007 John Wiley & Sons, Ltd. [source] Effect of package light transmittance on the vitamin content of pasteurized whole milkPACKAGING TECHNOLOGY AND SCIENCE, Issue 4 2006Alexander Saffert Abstract Pasteurized whole milk (3% fat) was stored under fluorescent light at 8°C in clear 1 litre polyethylene terephthalate (PET) bottles and three variants of pigmented PET bottles with different light transmittance. Changes in the vitamin content were monitored over a period of 10 days. Milk packed in pigmented PET bottles with the lowest light transmittance, which was stored in the dark under the same experimental conditions, served as the ,control' sample. Data were obtained for vitamin A (retinol), vitamin B2 (riboflavin) and vitamin B12 (cobalamin) content. Standard plate counts were determined to ensure an acceptable microbiological status of the pasteurized milk during the sampling period. In clear PET bottles a reduction of 22% of the initial content was observed for vitamin A and 33% for vitamin B2, while the vitamin B12 content remained almost stable. In all pigmented PET bottles the vitamin retention was significantly higher; the losses were 0,6% for vitamin A and 11,20% for vitamin B2, depending on the pigmentation level, as compared to 6% for vitamin A and no significant loss for vitamin B2 in the ,control' sample. An impact of the package light transmittance on the vitamin B12 content could not be observed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Cost-efficiency of Subsampling Protocols to Evaluate Oribatid-Mite Communities in an Amazonian SavannaBIOTROPICA, Issue 6 2008Evanira M. R. Santos ABSTRACT Sampling oribatid mites in large areas using conventional methods is expensive, time-consuming, and this constrains their use in environmental monitoring programs. We used samples collected in 38 plots of 3.75 ha spread over 30,000 ha in an Amazonian savanna to evaluate the reduction in costs and person-hours in sampling and sorting and to elaborate cost-effective protocols. Ten samples per plot were collected and extracted using a Berlese-Tullgren apparatus. In the laboratory, samples were reduced to 50, 25, 12.5, and 6.25 percent of the initial content. Field-effort reduction was estimated by reducing the number of subsamples per plot. Dissimilarity matrices were generated using Bray,Curtis, Sørensen, and Chao,Sørensen indices. Correlations between each reduced-effort dissimilarity matrix and 100 or 50 percent sorting were used as an index of how much information was retained in reduced-effort sampling, and could still be used in multivariate analyses. The effects of most predictor variables on mite composition were detected in data based on every level of sample reduction. The intensive sampling was insufficient to reveal the full oribatid-mite fauna in the savanna; as more plots were sampled, more species were recorded. Our data indicate subsampling protocols for biodiversity assessment of oribatid mites in savanna that increase field and laboratory efficiency, and optimize both taxonomic and ecological aspects of the investigation. RESUMO A coleta de ácaros oribatídeos em grandes áreas usando métodos convencionais é dispendiosa e demorada, limitando o uso desses animais em programas de monitoramento ambiental. Foram coletados ácaros oribatídeos em 38 parcelas de 3.75 ha distribuídas sobre uma área de 30.000 ha em uma savana amazônica. Com o objetivo de elaborar protocolos simples e eficientes, foi avaliada a redução dos custos e do tempo para a coleta e a triagem desses animais. Em cada parcela foram coletadas 10 subamostras compostas, que foram extraídas com aparato de Berlese-Tullgren e reduzidas em porcentagens de 50, 25, 12.5 e 6.25 do conteúdo inicial. A diminuição do esforço do campo foi estimada pela redução do número de amostras por parcela. Análise de ordenação multidimensional foi usada para gerar matrizes de dissimilaridade. Correlações entre cada matriz de dissimilaridade do esforço reduzido e triagem de 100 ou 50 por cento foram usadas como um índice da informação mantida e que ainda poderia ser usada nas análises multivariadas. Houve o efeito da presença de arbustos sobre a composição de ácaros em dados baseados em cada nível de redução das amostras. A coleta intensiva não foi suficiente para observar a riqueza completa de espécies na savana; quanto mais parcelas eram coletadas, mais espécies foram registradas. Os dados indicam protocolos de subamostragem para inventários da biodiversidade de ácaros oribatídeos em savanas, que podem aumentar a eficiência no campo e no laboratório, além de aperfeiçoar o aspecto taxonômico e ecológico da investigação. [source] Synthesis of 1-amino-2-methylindoline by Raschig process: Parallel reactions, modeling, and optimizationINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 10 2002M. Elkhatib The reaction between chloramine and 2-methylindoline was studied at pH 12.89, T = 40°C, and for different initial concentrations of reactants. The interaction includes two concurrent bimolecular mechanisms leading to 1-amino-2-methylindoline and 2-methylindole. The rate laws were determined at the first moments of the reaction by using a differential method. By considering the totality of the reactions that occur in the medium, an appropriate mathematical model was developed. It permits to follow the evolution of the system over time and to calculate the final yields of reaction products. An optimization in terms of the initial contents of 2-methylindoline and chloramine was performed. It indicated that the maximum yield of 1-amino-2-methylindoline does not exceed 56%. The results show the limit of the Raschig process for the synthesis of indolic hydrazines in aqueous medium. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 575,584, 2002 [source] Growth characteristics of Bacillus subtilis (natto) in milkINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2010YUTAKA KITAMURA In this paper, Bacillus subtilis (natto) was incubated to develop a possible functional ingredient in ice cream. A lab-scale culture revealed that incubation in the sterilised milk without dilution and concentration at 37°C for 28 h could obtain ideal growth characteristics of Bacillus subtilis (natto), especially with continuous aeration. Following freezing operation of the cultured milk, survival content of Bacillus subtilis (natto) was at 49,92%, while nattokinase activity was conserved at 62,98% comparing with the initial contents, which indicating a potential for application of natto functional ingredient in frozen milk products. [source] Photocatalytic Deposition of Silver Nanoparticles onto Organic/Inorganic Composite NanofibersMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2006Sang Kyoo Lim Abstract Summary: In this work, silver nanoparticles were embedded in electrospun organic/inorganic composite nanofibers consisting of PAN and TiO2 through photocatalytic reduction of the silver ions in silver nitrate solutions under UV irradiation. The morphology and diameter of PAN/TiO2 composite nanofibers could be controlled by varying the initial contents of TiO2 in the spinning solution. From TEM images and UV-Vis spectra, it has been confirmed that monodisperse silver nanoparticles with a diameter of ,2 nm were deposited selectively upon the titania of the as prepared composite nanofibers. The amount of Ag nanoparticles embedded on composite nanofibers was greatly influenced by the amount of TiO2 in composite nanofibers, reflecting the role of titania as the inorganic stabilizer and photocatalyst. Morphology of silver nanoparticles embedded on PAN/TiO2 composite nanofibers. [source] | ||||||||||||||||