bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laccase‐Mediated Remazol Brilliant Blue R Decolorization in a Fixed‐Bed Bioreactor
Authors: Palmieri Gianna , Giardina Paola , Sannia Giovanni 
Published: October 2005

AbstractA crude laccase mixture preparation from Pleurotus ostreatus cultures supplemented with copper and ferulic acid was used to decolorize the anthraquinonic dye Remazol Brilliant Blue R (RBBR). Performance of this enzymatic system was tested, and a maximum of 70% decolorization was achievable under optimal conditions. The crude preparation was immobilized by entrapment in copper alginate beads attaining 65% yield of laccase activity. Stability of the immobilized laccases was remarkably increased in comparison with that of the free enzyme preparation. Efficiency of the immobilized system was evaluated during stepwise dye additions in batch operations. Under the best conditions, 70% RBBR decolorization was achieved even after 20 cycles, although decolorization time exponentially increased after the 10th cycle. Different fixed‐bed bioreactors were prepared and analyzed in continuous decolorization processes. The best performance was obtained by decreasing the amount of enzyme loaded and by improving laccase retention using chitosan‐coated alginate beads.
Production of Biodiesel by Lipase‐Catalyzed Transesterification of Vegetable Oils: A Kinetics Study
Authors: Al‐Zuhair Sulaiman 
Published: October 2005

AbstractKinetics of production of biodiesel by enzymatic methanolysis of vegetable oils using lipase has been investigated. A mathematical model taking into account the mechanism of the methanolysis reaction starting from the vegetable oil as substrate, rather than the free fatty acids, has been developed. The kinetic parameters were estimated by fitting the experimental data of the enzymatic reaction of sunflower oil by two types of lipases, namely, Rhizomucor miehei lipase (RM) immobilized on ion‐exchange resins and Thermomyces lanuginosa lipase (TL) immobilized on silica gel. There was a good agreement between the experimental results of the initial rate of reaction and those predicted by the proposed model equations, for both enzymes. From the proposed model equations, the regions where the effect of alcohol inhibition fades, at different substrate concentrations, were identified. The proposed model equation can be used to predict the rate of methanolysis of vegetable oils in a batch or a continuous reactor and to determine the optimal conditions for biodiesel production.
Functional food science and gastrointestinal physiology and function
Authors: Salminen S. , Bouley C. , Boutron M.-C. , Cummings J. H. , Franck A. , Gibson G. R. , Isolauri E. , Moreau M.-C. , Roberfroid M. , Rowland I. 
Published: October 2005

AbstractThe gut is an obvious target for the development of functional foods, acting as it does as the interface between diet and the metabolic events which sustain life. The key processes in digestive physiology which can be regulated by modifying diet are satiety, the rate and extent of macronutrient breakdown and absorption from the small bowel, sterol metabolism, the colonic microflora, fermentation, mucosal function and bowel habit, and the gut immune system. The intestinal microflora is the main focus of many current functional foods. Probiotics are foods which contain live bacteria which are beneficial to health whilst prebiotics, such as certain non-digestible oligosaccharides which selectively stimulate the growth of bifidobacteria in the colon, are already on the market. Their claimed benefits are to alleviate lactose maldigestion, increase resistance to invasion by pathogenic species of bacteria in the gut, stimulate the immune system and possibly protect against cancer. There are very few reports of well-designed human intervention studies with prebiotics as yet. Certain probiotic species have been shown to shorten the duration of rotavirus diarrhoea in children but much more work is needed on the mechanism of immunomodulation and of competitive exclusion and microflora modification. The develop-ment of functional foods for the gut is in its infancy and will be successful only if more fundamental research is done on digestive physiology, the gut microflora, immune system and mucosal function.
Functional food science and behaviour and psychological functions
Authors: Bellisle F. , Blundell J. E. , Dye L. , Fantino M. , Fern E. , Fletcher R. J. , Lambed J. , Roberfroid M. , Specter S. , Westenhöfer J. , Westerterp-Plantenga M. S. 
Published: October 2005

AbstractThe impact of ingesting various foods on psychological and behavioural functions is a topic of both interest and concern to the general public. In this article, the scientific literature concerning demonstrated cause-and-effect relationships is reviewed, beginning with methodological considerations specific to the quantification of particular behaviours and psychological events. The essential function of food is to satisfy hunger and the need for essential nutrients. The contributions of macronutrients to appetite and satiety are described, as well as their impact on metabolism and energy balance. Functional properties of macronutrient substitutes (high intensity sweeteners, fat replacers) and flavour enhancers are examined in relation to their contribution to hunger, satiety, and energy balance. The effects of foods and individual nutrients on the performance of diverse psychomotor tasks are studied with consideration given to the various validated quantitative tools used to assess behaviour. The effects of food components on activation, sedation, and affective states such as dysphoria are also reviewed, with special attention given to brain function and neuroactive substances such as serotonin and the endorphins. The case of hyperactivity in children is given special emphasis with reference to the potential influence of sugar and food additives. Safety issues related to food constituents and additives are discussed. Finally, a set of criteria is proposed for the evaluation and elaboration of studies in the behavioural and psychological fields, along with suggestions for future research.
Modelling the human rhesus proteins: implications for structure and function
Authors: Conroy Matthew J. , Bullough Per A. , Merrick Mike , Avent Neil D. 
Published: October 2005

SummaryThe mammalian rhesus (Rh) proteins that carry the Rh blood group antigens of red blood cells are related to the ammonium channel (Amt) proteins found in both pro‐ and eukaryotes. However, despite their clinical importance the structure of the Rh antigens is presently unknown. We have constructed homology models of the human Rh proteins, RhD and RhAG using the structure of the Escherichia coli ammonia channel AmtB as a template, together with secondary structure predictions and the extensive available biochemical data for the Rh proteins. These models suggest that RhAG and the homologous non‐erythrocyte Rhesus glycoproteins, RhBG and RhCG, have a very similar channel architecture to AmtB. By comparison, RhD and RhCE have a different arrangement of residues, indicating that if they function as ammonia channels at all, they must do so by a different mechanism. The E. coli AmtB protein is a homotrimer and our models provoke a reassessment of the widely accepted tetrameric model of the organisation of the erythrocyte Rh complex. A critical analysis of previously published data, together with sequencing yield data, lead us to suggest that the erythrocyte Rh complex could indeed also be trimeric.
Interactive effects of elevated CO2, N deposition and climate change on extracellular enzyme activity and soil density fractionation in a California annual grassland
Authors: Henry Hugh A. L. , Juarez John D. , Field Christopher B. , Vitousek Peter M. 
Published: October 2005

AbstractElevated CO2, N deposition and climate change can alter ecosystem‐level nutrient cycling both directly and indirectly. We explored the interactive effects of these environmental changes on extracellular enzyme activity and organic matter fractionation in soils of a California annual grassland. The activities of hydrolases (polysaccharide‐degrading enzymes and phosphatase) increased significantly in response to nitrate addition, which coincided with an increase in soluble C concentrations under ambient CO2. Water addition and elevated CO2 had negative but nonadditive effects on the activities of these enzymes. In contrast, water addition resulted in an increase in the activities of lignin‐degrading enzymes (phenol oxidase and peroxidase), and a decrease in the free light fraction (FLF) of soil organic matter. Independent of treatment effects, lignin content in the FLF was negatively correlated with the quantity of FLF across all samples. Lignin concentrations were lower in the aggregate‐occluded light fraction (OLF) than the FLF, and there was no correlation between percent lignin and OLF quantity, which was consistent with the protection of soil organic matter in aggregates. Elevated CO2 decreased the quantity of OLF and increased the OLF lignin concentration, however, which is consistent with increased degradation resulting from increased turnover of soil aggregates. Overall, these results suggest that the effects of N addition on hydrolase activity are offset by the interactive effects of water addition and elevated CO2, whereas water and elevated CO2 may cause an increase in the breakdown of soil organic matter as a result of their effects on lignin‐degrading enzymes and soil aggregation, respectively.
Scenarios of freshwater fish extinctions from climate change and water withdrawal
Authors: Xenopoulos Marguerite A. , Lodge David M. , Alcamo Joseph , Märker Michael , Schulze Kerstin , Van Vuuren Detlef P. 
Published: October 2005

AbstractReductions in river discharge (water availability) like those from climate change or increased water withdrawal, reduce freshwater biodiversity. We combined two scenarios from the Intergovernmental Panel for Climate Change with a global hydrological model to build global scenarios of future losses in river discharge from climate change and increased water withdrawal. Applying these results to known relationships between fish species and discharge, we build scenarios of losses (at equilibrium) of riverine fish richness. In rivers with reduced discharge, up to 75% (quartile range 4–22%) of local fish biodiversity would be headed toward extinction by 2070 because of combined changes in climate and water consumption. Fish loss in the scenarios fell disproportionately on poor countries. Reductions in water consumption could prevent many of the extinctions in these scenarios.
Spatial analysis of growing season length control over net ecosystem exchange
Authors: Churkina Galina , Schimel David , Braswell Bobby H. , Xiao Xiangming 
Published: October 2005

AbstractUsing data from 28 flux measurement sites, we performed an analysis of the relationship between annual net ecosystem exchange (NEE) and the length of the carbon uptake period (CUP) (the number of days when the ecosystem is a net carbon sink). The observations suggest a linear correlation between the two quantities. The change in annual carbon exchange per day of the CUP differs significantly between deciduous and evergreen vegetation types. The sites containing vegetation with short‐lived foliage (less than 1 year) have higher carbon uptake and respiration rates than evergreen vegetation. The ratio between mean daily carbon exchange rates during carbon uptake and release periods is relatively invariant (2.73±1.08) across different vegetation types. This implies that a balance between carbon release and uptake periods exists despite different photosynthetic pathways, life forms, and leaf habits. The mean daily carbon sequestration rate for these ecosystems never exceeds the carbon emission rate by more than a factor of 3. Growing season lengths for the study sites were derived from the normalized difference vegetation index (NDVI) of advanced very‐high‐resolution radiometer and from the enhanced vegetation index (EVI) of VEGETATION SPOT‐4. NDVI and EVI were found to be closely related to the CUP, and consequently they also can be used to approximate annual carbon exchange of the ecosystems. This approach has potential for allowing extrapolation of NEE over large areas from remotely sensed data, given a certain amount of ancillary information. This method could complement the currently existing techniques for extrapolation, which rely upon modeling of the individual gross fluxes.
The conversion of the corn/soybean ecosystem to no‐till agriculture may result in a carbon sink
Authors: Bernacchi Carl J. , Hollinger Steven E. , Meyers Tilden 
Published: October 2005

AbstractMitigating or slowing an increase in atmospheric carbon dioxide concentration ([CO2]) has been the focus of international efforts, most apparent with the development of the Kyoto Protocol. Sequestration of carbon (C) in agricultural soils is being advocated as a method to assist in meeting the demands of an international C credit system. The conversion of conventionally tilled agricultural lands to no till is widely accepted as having a large‐scale sequestration potential. In this study, C flux measurements over a no‐till corn/soybean agricultural ecosystem over 6 years were coupled with estimates of C release associated with agricultural practices to assess the net biome productivity (NBP) of this no‐till ecosystem. Estimates of NBP were also calculated for the conventionally tilled corn/soybean ecosystem assuming net ecosystem exchange is C neutral. These measurements were scaled to the US as a whole to determine the sequestration potential of corn/soybean ecosystems, under current practices where 10% of agricultural land devoted to this ecosystem is no‐tilled and under a hypothetical scenario where 100% of the land is not tilled. The estimates of this analysis show that current corn/soybean agriculture in the US releases ∼7.2 Tg C annually, with no‐till sequestering ∼2.2 Tg and conventional‐till releasing ∼9.4 Tg. The complete conversion of land area to no till might result in 21.7 Tg C sequestered annually, representing a net C flux difference of ∼29 Tg C. These results demonstrate that large‐scale conversion to no‐till practices, at least for the corn/soybean ecosystem, could potentially offset ca. 2% of annual US carbon emissions.
Enhanced responsiveness to antigen contributes more to immunological memory in CD4 T cells than increases in the number of cells
Authors: Bates John T. , Pat Bucy R. 
Published: October 2005

SummaryAlthough immunological memory is characterized by both an increase in the frequency of antigen‐specific T cells and a qualitative change in the pattern of their subsequent response, it is not clear which of these components is more significant in the overall enhanced response to secondary stimulation. To address this question for the CD4+ T‐cell response, T‐cell receptor (TCR) Tg T cells were adoptively transferred to normal syngeneic mice that were immunized with the relevant peptide. After the initial expansion of TCR Tg T cells, the size of the subsequent memory population of T cells was approximately the same as the size of the starting population, independent of the number of TCR Tg cells initially transferred. This result was not caused by redistribution of memory cells into non‐lymphoid tissues, although the relative frequency of antigen‐specific T cells in these sites was increased after immunization. The fraction of the antigen specific TCR Tg cells that responded by production of either interleukin‐2 or interferon‐γin vitro was substantially higher after immunization. Thus, the increased frequency of functionally responsive T cells was primarily caused by a higher fraction of responding T cells, rather than a substantial increase in the absolute number of antigen specific CD4+ TCR Tg T cells.
Construction and characterization of a humanized anti‐human CD3 monoclonal antibody 12F6 with effective immunoregulation functions
Authors: Li Bohua , Wang Hao , Dai Jianxin , Ji Junjie , Qian Weizhu , Zhang Dapeng , Hou Sheng , Guo Yajun 
Published: October 2005

Summary12F6 is a murine anti‐human CD3 monoclonal antibody, which competes with OKT3 for binding to human T cells and possesses more effective T‐cell suppression and activation properties compared to OKT3. It thus exhibits the potential to be developed as an immunoregulation agent for manipulating T‐cell functions and preventing acute allograft rejection. In an attempt to minimize the immunogenicity of murine 12F6 (m12F6) for potential clinical application, a humanized version of 12F6, denoted as hu12F6, was successfully constructed by complementary determining region (CDR) grafting and shown to maintain both T‐cell activation and suppression activities similar to m12F6. Furthermore, in order to reduce the first dose reaction syndrome caused by T‐cell activation following the first administration of anti‐CD3 antibodies, two amino acid mutations were introduced into the Fc region of hu12F6, resulting in the Fc‐mutated 12F6 humanized antibody (hu12F6mu). This Fc‐mutated version displayed a similar antigen‐binding affinity and specificity compared with hu12F6 and m12F6 but with much weaker FcR binding activity. hu12F6mu was shown to be much less potent in the induction of T‐cell proliferation, cytokine release (tumour necrosis factor‐α, interferon‐γ and interleukin‐10) and early activation marker expression on the cell surface (CD69 and CD25) than parental 12F6 and OKT3 did. In contrast, hu12F6mu was effective in modulating T‐cell receptor/CD3 and inhibiting mixed lymphocyte reaction with a similarity as compared to m12F6 and OKT3. In conclusion, the resultant hu12F6mu was much less mitogenic to T cells but retained potent immunosuppression, suggesting it might be an alternative to OKT3 as an immunosuppressive drug with less immunogenicity and toxicity for clinical application.
Resistance to chlamydial lung infection is dependent on major histocompatibility complex as well as non‐major histocompatibility complex determinants
Authors: Qiu Hongyu , Wang Shuhe , Yang Jie , Fan Yijun , George Joyee Antony , Han Xiaobing , Jiao Lei , Yang Xi 
Published: October 2005

SummaryOur previous work has shown that C3H/HeN and C57BL/6 mice have differential susceptibility to Chlamydia trachomatis mouse pneumonitis (C. muridarum) lung infection. C3H/HeN (H‐2k) mice were found to be highly susceptible to C. muridarum infection with higher mortality and more severe morbidity compared to C57BL/6 (H‐2b) mice. To examine the role of major histocompatibility complex (MHC) genes on host resistance to chlamydial lung infection, we compared MHC congenic mice, B6.H2k [C57BL/6 background, C3H MHC (H‐2k)] and C3H.H2b [C3H/HeN background, C57BL/6 MHC (H‐2b)] and their corresponding wild type C57BL/6 mice and C3H/HeN mice, respectively, in susceptibility to C. muridarum infection. We found that B6.H2k, C3H.H2b and C3H/HeN mice are more susceptible to chlamydial lung infection compared to the wild type C57BL/6 mice by showing more serious body weight loss, higher in vivo chlamydial growth and more severe pathologic changes. Congenic B6.H2k mice showed significantly lower levels of IL‐12 and IFN‐γ production compared to C57BL/6 as well as C3H/HeN and C3H.H2b mice. One the other hand, although congenic C3H.H2b mice displayed similar cytokine response to C57BL/6 mice, they were highly susceptible to C. muridarum infection. Overall, the results suggest that protection against chlamydial lung infection is both MHC and non‐MHC gene dependent, and that the interaction between MHC and non‐MHC elements may contribute to host resistance to chlamydial infection.
Toll‐like receptor 3 agonist poly(I:C)‐induced antiviral response in human corneal epithelial cells
Authors: Kumar Ashok , Zhang Jing , Yu Fu‐Shin X. 
Published: October 2005

SummaryThe objective of this study was to examine the expression of Toll‐like receptor 3 (TLR3) by human corneal epithelial cells (HCECs) and to determine whether exposure to the TLR3 agonist polyinosinic‐polycytidylic acid [poly(I:C)]induces an antiviral response in these cells. Fluorescence‐activated cell sorter (FACS) analysis revealed TLR3 to be constitutively expressed and distributed intracellularly in HCECs. Stimulation of HCECs with the TLR3 agonist poly(I:C) induced the activation of nuclear factor (NF)‐κB and production of the proinflammatory cytokine interleukin (IL)‐6 and the chemokine IL‐8. Upon exposure to poly(I:C), HCECs initiated a potent antiviral response resulting in an increase of interferon (IFN)‐β mRNA expression (7‐fold). Poly(I:C) stimulation also up‐regulated mRNA expression of the antiviral chemokine IFN‐γ inducible protein 10 (IP10), myxovirus resistance gene A and 2′,5′‐oligoadenylate synthetase (5‐, 10‐ and 9‐fold, respectively), and secretion of IP10. These responses were also induced by exogenously added type 1 IFNs, but could not be blocked by pretreatment of the cells with anti‐TLR3 monoclonal antibody, suggesting that the receptor was not expressed on the cell surface. Furthermore, incubation of HCECs with an endosomal acidification inhibitor, chloroquine, markedly inhibited poly(I:C)‐mediated IFN‐β expression in HCECs. These results suggest that corneal epithelial cells are important sentinels of the corneal innate immune system against viral infection, and that stimulation of TLR3 can induce the expression of key proinflammatory cytokines and chemokines and antiviral genes that help in the defence of the cornea against viral infection.
Diagenetic signatures of stratal surfaces in the Upper Jurassic Fulmar Formation, Central North Sea, UKCS
Authors: BURNS FIONA E. , BURLEY STUART D. , GAWTHORPE ROB L. , POLLARD JOHN E. 
Published: October 2005

AbstractSedimentation rate and changes in relative sea level affect early diagenetic cementation along key stratal surfaces within the deeply buried Upper Jurassic Fulmar Formation, South Central Graben, UKCS. As a result of the bioturbated nature of the shallow marine strata, variations in ichnofabrics and cross‐cutting relationships between trace fossils are important in identifying and correlating stratal surfaces. Two transgressive and two regressive surfaces/sequence boundaries were studied, using petrographical, mineralogical and geochemical techniques. Cements, including early diagenetic pyrite framboids, grain‐rimming apatite, microcrystalline dolomite and ankerite, occur at, above and immediately below both transgressive and forced regressive surfaces/sequence boundaries. Breaks or subdued rates of sedimentation associated with both types of surfaces meant that the sediment package resided within early diagenetic zones for prolonged periods of time, enhancing diagenetic reactions at and below the surfaces. The distribution of ankerite, despite being a deep‐burial cement, was primarily controlled by concentrations of bioclasts that are particularly abundant at transgressive surfaces. The diagenetic character of the forced regressive surfaces/sequence boundaries is more complex than that of the transgressive surfaces, both in terms of mineralogy and paragenesis. This is attributed to the superimposition of diagenetic assemblages as a result of erosion, re‐sedimentation and sediment by‐passing. Although the diagenetic signature of the surfaces has been modified by dissolution/replacement reactions during deep burial, early diagenetic signatures can still be distinguished.