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High Production (high + production)
Terms modified by High Production Selected AbstractsHigh Production of D -Tagatose, a Potential Sugar Substitute, Using Immobilized L -Arabinose IsomeraseBIOTECHNOLOGY PROGRESS, Issue 1 2001Pil Kim An L -arabinose isomerase of Escherichia coli was immobilized using covalent binding to agarose to produce D -tagatose, a bulking sweetener that can be economically used as a sugar substitute. The immobilized L -arabinose isomerase stably produced an average of 7.5 g-tagatose/L·day for 7 days with a productivity exceeding that of the free enzyme (0.47 vs 0.30 mg/U·day). Using a scaled-up immobilized enzyme system, 99.9 g-tagatose/L was produced from galactose with 20% equilibrium in 48 h. The process was repeated two more times with production of 104.1 and 103.5 g-tagatose/L. D -Tagatose production using an immobilized L -arabinose isomerase has a high potential for commercial application. [source] Tectonic control of bioalteration in modern and ancient oceanic crust as evidenced by carbon isotopesISLAND ARC, Issue 1 2006Harald Furnes Abstract We review the carbon-isotope data for finely disseminated carbonates from bioaltered, glassy pillow rims of basaltic lava flows from in situ slow- and intermediate-spreading oceanic crust of the central Atlantic Ocean (CAO) and the Costa Rica Rift (CRR). The ,13C values of the bioaltered glassy samples from the CAO show a large range, between ,17 and +3, (Vienna Peedee belemnite standard), whereas those from the CRR define a much narrower range, between ,17, and ,7,. This variation can be interpreted as the product of different microbial metabolisms during microbial alteration of the glass. In the present study, the generally low ,13C values (less than ,7,) are attributed to carbonate precipitated from microbially produced CO2 during oxidation of organic matter. Positive ,13C values >0, likely result from lithotrophic utilization of CO2 by methanogenic Archaea that produce CH4 from H2 and CO2. High production of H2 at the slow-spreading CAO crust may be a consequence of fault-bounded, high-level serpentinized peridotites near or on the sea floor, in contrast to the CRR crust, which exhibits a layer-cake pseudostratigraphy with much less faulting and supposedly less H2 production. A comparison of the ,13C data from glassy pillow margins in two ophiolites interpreted to have formed at different spreading rates supports this interpretation. The Jurassic Mirdita ophiolite complex in Albania shows a structural architecture similar to that of the slow-spreading CAO crust, with a similar range in ,13C values of biogenic carbonates. The Late Ordvician Solund,Stavfjord ophiolite complex in western Norway exhibits structural and geochemical evidence for evolution at an intermediate-spreading mid-ocean ridge and displays ,13C signatures in biogenic carbonates similar to those of the CRR. Based on the results of this comparative study, it is tentatively concluded that the spreading rate-dependent tectonic evolution of oceanic lithosphere has a significant control on the evolution of microbial life and hence on the ,13C biosignatures preserved in disseminated biogenic carbonates in glassy, bioaltered lavas. [source] Optimization of C:N ratio and minimal initial carbon source for poly(3-hydroxybutyrate) production by Bacillus megateriumJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2009Débora Jung Luvizetto Faccin Abstract BACKGROUND: The aim of this research was the optimization of poly(3-hydroxybutyrate),P(3HB),production in submerged cultures of Bacillus megaterium in a mineral medium using sucrose as carbon source and nitrogen as the limiting substrate. Small-scale experiments were carried out in shake flasks at 30 °C and 160 rpm in order to evaluate the best initial sucrose concentration and carbon:nitrogen ratio to maximize biomass accumulation and biopolymer production. An objective function in terms of residual sucrose and P(3HB) production was proposed in order to optimize the amount of carbon source used and the production of P(3HB). RESULTS: High production of P(3HB) was obtained, with approximately 70% (CDW) accumulation in cells without nitrogen limitation and strongly correlated with the pH of the culture. Scaling-up the system to cultures in a bioreactor, with or without pH control, a reduction of P(3HB) accumulation (around 30% CDW) was observed when compared with shaker cultures, suggesting a possible role of oxygen limitation as a stress signaling for P(3HB) synthesis. CONCLUSIONS: Results of our experiments showed that Bacillus megaterium was able to produce P(3HB) at one of the highest production rates so far reported for this bacterium, making this microorganism very interesting for industrial applications. Comparisons of shaker and bench-scale bioreactor experiments show both the importance of pH and aeration strategies. It is likely that complex aeration strategies linked to cell metabolism will be necessary for further developments using this bacterium. Copyright © 2009 Society of Chemical Industry [source] Screening of urocanic acid isomers in human basal and squamous cell carcinoma tumors compared with tumor periphery and healthy skinEXPERIMENTAL DERMATOLOGY, Issue 10 2008Juan Manuel Decara Abstract:,Trans -urocanic acid is a major chromophore for ultraviolet (UV) radiation in human epidermis. The UV induces photoisomerization of trans -urocanic acid (tUCA) form to cis -urocanic acid (cUCA) and has been reported as an important mediator in the immunosuppression induced by UV. This immunomodulation has been recognized as an important factor related to skin cancer development. This is the first time that UCA isomers have been measured in epidermis of skin biopsies from patients with squamous cell carcinoma (SCC) and with basal cell carcinoma (BCC) and compared with the tumor periphery and biopsies of healthy photoexposed and non-photoexposed skin as controls. The UCA isomers were separated and quantified by high performance liquid chromatography. Analysis of UCA in healthy skin showed significant increase in total UCA content in non-photoexposed body sites compared with highly exposed skins. In contrast, the percentage of cUCA was higher in photoexposed body sites. Maximal levels of cUCA were found in cheek, forehead and forearm and lower levels in abdomen and thigh. No differences were found in total UCA concentration between the tumor samples and healthy photoexposed skin. However, differences were found in relation between isomers. Higher levels of cUCA were detected in SCC biopsies (44% of total UCA) compared with samples of BCC and that of healthy photoexposed skin (30%). These results suggest that the UV radiation exposure, a main factor in development of SCC can be mediated, apart from direct effect to cells (DNA damage), by immunosuppression pathways mediated by high production of cUCA. [source] Tyrosine nitration in the human leucocyte antigen-G-binding domain of the Ig-like transcript 2 proteinFEBS JOURNAL, Issue 15 2009Angel Díaz-Lagares Ig-like transcript 2 (ILT2) is a suppressive receptor that participates in the control of the autoimmune reactivity. This action is usually carried out in a proinflammatory microenvironment where there is a high production of free radicals and NO. However, little is known regarding whether these conditions modify the protein or affect its suppressive functions. The present study aimed to investigate the suppressive response of the ILT2 receptor under oxidative stress. To address this topic, we treated the ILT2-expressing natural killer cell line, NKL, with the NO donor N -(4-[1-(3-aminopropyl)-2-hydroxy-2-nitrosohydrazino]butyl)propane-1,3-diamine (DETA-NO). We observed that DETA-NO caused ILT2 protein nitration. MS analysis of the chimeric recombinant human ILT2-Fc protein after treatment with the peroxynitrite donor 3-(morpholinosydnonimine hydrochloride) (SIN-1) showed the nitration of Tyr35, Tyr76 and Tyr99, which are involved in human leucocyte antigen-G binding. This modification is selective because other Tyr residues were not modified by SIN-1. Recombinant human ILT2-Fc treated with SIN-1 bound a significantly higher quantity of human leucocyte antigen-G than untreated recombinant human ILT2-Fc. DETA-NO did not modify ILT2 mRNA expression or protein expression at the cell surface. Preincubation of NKL cells with DETA-NO decreased the cytotoxic lysis of K562-human leucocyte antigen-G1 cells compared to untreated NKL cells (P < 0.05) but increased cytotoxicity against K562-pcDNA cells (P < 0.05). Intracellular tyrosine phosphorylation produced after human leucocyte antigen-G binding was not affected by DETA-NO cell pretreatment. These results support the hypothesis that the ILT2,human leucocyte antigen-G interaction should have a central role in tolerance under oxidative stress conditions when other tolerogenic mechanisms are inhibited. Structured digital abstract ,,MINT-7144982: ILT2 (uniprotkb:Q8NHL6) binds (MI:0407) to HLA-G (uniprotkb:P17693) by affinity technologies (MI:0400) [source] Effects of sequential depositional basins on lake response to urban and agricultural pollution: a palaeoecological analysis of the Qu'Appelle Valley, Saskatchewan, CanadaFRESHWATER BIOLOGY, Issue 3 2000Aruna S. Dixit 1. Palaeolimnological analyses of fossil diatoms and pigments were conducted in four lakes of the Qu'Appelle Valley, Saskatchewan, Canada, to quantify the effect of upstream depositional basins on lake response to urban and agricultural human activities. Pasqua, Echo, Mission and Katepwa lakes exhibit similar modern limnological characteristics, lie sequentially downstream from urban point sources of growth-limiting nitrogen (N), yet drain similarly large areas of farmland (38,40 × 103 km2). 2. Analyses indicated that all lakes were naturally productive, contained eutrophic diatoms (i.e. Stephanodiscus niagarae, S. hantzchii, S. parvus and Aulacoseira granulata), and supported blooms of colonial (as myxoxanthophyll) and potentially toxic N-fixing cyanobacteria (aphanizophyll), even prior to the onset of European settlement (ca. 1890) and urban development (ca. 1930). 3. The onset of agricultural practices ca. 1890 had only modest effects on algal communities in the Qu'Appelle lakes, with subtle increases in eutrophic diatom species (Pasqua, Mission and Katepwa lakes) and 25,50% increases in pigment-inferred algal abundance (Echo, Mission and Katepwa lakes). 4. Despite naturally high production, total algal abundance (,-carotene) in upstream Pasqua Lake increased by more than 350% after intense urbanization beginning ca. 1930, while eutrophic diatoms became more common and cyanobacteria populations increased ten-fold. Principal components analysis (PCA) explained 64% of diatom variance, and identified three eras corresponding to baseline, pre-agricultural communities (1776,1890), an era of high production (ca. 1925,1960) and recent variable community composition following tertiary treatment of urban sewage (ca. 1977,1990). 5. Analyses of three downstream lakes demonstrated that urban impacts following 1930 remained evident in fossil profiles of ,-carotene and myxoxanthophyll, but that large blooms of N-fixing cyanobacteria were restricted to the past 25 years at downstream Mission and Katepwa lakes. Similarly, PCA showed that fossil diatom assemblages exhibited little directional variation until the 1970s. 6. Together, these analyses support the hypothesis that upstream lakes were effective at reducing the impacts of point-source urban nutrients on downstream lakes. In contrast, diffuse agricultural activities had only limited impacts on water quality and these were less well ameliorated by upstream basins. [source] Organic facies and geochemical aspects in Neogene neritic sediments of the Takafu syncline area of central Japan: Paleoenvironmental and sedimentological reconstructionsISLAND ARC, Issue 4 2006Ken Sawada Abstract Organic petrological observations of kerogen macerals and organic geochemical analyses of carbon isotopes of kerogen macerals and biomarkers were conducted on Neogene neritic sediments of the Takafu syncline area of central Japan. The Senmi, Sakainomiya and Lower Shigarami Formations in that area were deposited at the neritic provinces on the southern edge of the paleo-Japan Sea during the Late Miocene to Early Pliocene. Sedimentary organic matter in these formations was almost terrigenous in origin. Changes in kerogen maceral compositions reflect sedimentological and tectonic histories evaluated in previous studies from sedimentary facies and paleontology. It was found that carbon isotope ratios (,13C) of kerogen macerals increased from ,28, to ,25, from the Sakainomiya to the lower part of the Lower Shigarami Formations. The cause of that increase was presumably the expansion of C4 plants into southwest Japan. The timing was concordant with that of the expansion of C4 plant grasslands in East Asia. The oxicity (oxic to anoxic) conditions of sea bottoms evaluated from pristane/phytane ratios varied. Particularly, in the lower part of the Senmi Formation, layers in which no steroid biomarkers could be detected were found, and had presumably formed under oxic conditions when strong biodegradation had occurred. Concentrations of regular (C27,C29) steranes and dinosteranes were higher in the Sakainomiya and Lower Shigarami Formations. This indicates that dinoflagellates-dominant primary productions were higher at those stages. In addition, concentrations of diatomaceous biomarkers such as C26 norsterane increased from the Lower Shigarami Formation, thus adding diatoms to the major producers. Furthermore, similar associations between the increases of ,13C values of kerogen macerals and concentrations of diatomaceous biomarkers were observed in the Takafu syncline area. Thus, the expansion of C4 plants was possibly associated with the high production of diatom in the shallow-marine areas of the paleo-Japan Sea during the Neogene Period. [source] Long-term effect of full-mouth tooth extraction on the responsiveness of peripheral blood monocytesJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2003Schelte J. Fokkema Abstract Background: As some residual inflammation may remain after periodontal therapy, the present pilot study investigated the long-term effect of full-mouth tooth extraction therapy on the responsiveness of peripheral blood monocytes in a case with generalized terminal adult periodontitis. Methods: Before and 3, 9, 20 and 32 months after therapy, venous blood was collected. Total and differential white blood cell counts were determined and whole blood cell cultures (WBCC) were incubated with lipopolysaccharide (LPS) to stimulate the production of inflammatory mediators by monocytes. Results: After full-mouth tooth extraction, the numbers of total peripheral white blood cells and neutrophils decreased over time. The release of the chemokines interleukin (IL)-8 and macrophage chemoattractant protein (MCP)-1 in the cultures decreased twofold over time, whereas no changes were seen for the other studied cytokines, chemokines and prostaglandin E2. Conclusion: On the basis of previous studies and the present case, the high production of IL-8 and MCP-1 by monocytes in LPS-stimulated WBCC from periodontitis patients is most likely acquired, as their levels decrease over time when the periodontal infection is controlled. The possible connection between periodontitis and atherosclerosis through IL-8 and MCP-1 is discussed. Zusammenfassung Hintergrund: Da nach der parodontalen Therapie eine restliche Entzündung zurückbleiben kann, untersucht die vorliegende Studie den Langzeiteffekt einer vollständigen Zahnextraktion auf die Ansprechbarkeit der peripheren Blutmonozyten in einem Fall mit generalisierter unheilbarer Erwachsenen-Parodontitis. Methoden: Vor und 3, 9, 20 und 32 Monaten nach der Therapie wurde venöses Blut gesammelt. Der totale und differenzierte weiße Blutzellgehalt wurden bestimmt, und eine gesamte Blutzellkultur (WBCC) wurde mit Lipopolysaccharid inkubiert, um die Produktion von Entzündungsmediatoren durch Lymphozyten zu stimulieren. Ergebnisse: Nach der vollständigen Zahnextraktion verringerte sich die Zahl der totalen peripheren weißen Blutzellen und der Neutrophilen über die Zeit. Die Freisetzung des Chemokins Interleukin 8 (IL-8) und des Makrophagen chemoattraktanten Proteins (MCP) ,1 in den Kulturen verringerte sich zweifach über die Zeit, während für die anderen beobachteten Cytokine, Chemokine und Prostaglandin E2 keine Veränderungen festgestellt wurden. Schlussfolgerung: Auf der Basis vorheriger Studien und des vorliegenden Falls ist die hohe Produktion von IL-8 und MCP-1 durch Monozyten in LPS stimulierten WBCC von Parodontitis-Patienten sehr wahrscheinlich anzunehmen, da ihr Level über die Zeit abnimmt, wenn die parodontale Infektion kontrolliert ist. Die mögliche Verbindung zwischen Parodontitis und Arteriosklerose durch IL-8 und MCP-1 wird diskutiert. Résumé Contexte: Puisqu'après traitement parodontal, une inflammation résiduelle peut subsister, cette étude se propose de rechercher les effets à long terme de l'extraction complète des dents sur la réponse des monocytes périphériques dans un cas de parodontite de l'adulte terminale généralisée. Méthodes: Des prélèvements sanguins veineux ont été réalisés avant et 3, 9, 20 et 32 mois après traitement. Les comptages totaux et relatifs des cellules blanches sanguines furent déterminés et les cultures complètes de cellules sanguines (WBCC) furent incubées avec du lipopolysaccharide pour stimuler la production des médiateurs de l'inflammation par les monocytes. Résultats: Après l'extraction complète des dents, les nombres de cellules sanguines blanches totales périphériques et des neutrophiles diminuaient au cours du temps. Le relargage des chimiokines interleukine (IL)-8 et protéine chimio-attractante du macrophage (MCP)-1 dans les cultures diminuait deux fois au cours du temps, alors qu'aucun changement n'était observé pour les autres cytokines étudiées, chimiokines et prostaglandine E2. Conclusion: Sur la base d'études préalables, et les résultats issus de ce cas présent, la forte production d'IL-8 et de MCP-1 par les monocytes dans les WBCC stimulés par le LPS chez des patients atteints de parodontite semble être vraisemblablement acquise puisque leurs niveaux diminuent lorsque l'infection parodontale est contrôlée. La relation possible entre parodontite et l'athérosclérose par IL-8 et MCP-1 est discutée. [source] Plastic changes in seed dispersal along ecological succession: theoretical predictions from an evolutionary modelJOURNAL OF ECOLOGY, Issue 2 2005OPHÉLIE RONCE Summary 1We use a deterministic model to explore theoretically the ecological and evolutionary relevance of plastic changes in seed dispersal along ecological succession. Our model describes the effect of changing disturbance regime, age structure, density and interspecific competition as the habitat matures, enabling us to seek the evolutionarily stable reaction norm for seed dispersal rate as a function of time elapsed since population foundation. 2Our model predicts that, in the context of ecological succession, selection should generally favour plastic strategies allowing plants to increase their dispersal rate with population age, contrary to previous predictions of models that have assumed genetically fixed dispersal strategies. 3More complex patterns can evolve showing periods with high production of dispersing seeds separated by periods of intense local recruitment. These patterns are due to the interaction of individual senescence with change in ecological conditions within sites. 4Evolution of plastic dispersal strategies affects the patterns of density variation with time since foundation and accelerates successional replacement. An interesting parallel can be drawn between the evolution of age-specific dispersal rates in successional systems and the evolution of senescence in age-structured populations. 5Seed dispersal plasticity could be a potential mechanism for habitat selection in plants and have implications for range expansion in invasive species because recently founded populations at the advancing front may show different patterns to those in the established range. [source] Association of interleukin-1, polymorphism with recurrent aphthous stomatitis in Brazilian individualsORAL DISEASES, Issue 6 2006ALS Guimarães Background:, Recurrent aphthous stomatitis (RAS) is characterized by recurrent episodes of oral ulceration in an otherwise healthy individual. Some reports in the literature indicate that RAS may have immunological, psychological, genetic and microbiological bases. The purpose of the present study was to investigate the possible association between interleukin-1, (IL-1,) +3954 (C/T) genetic polymorphism and RAS in a sample of Brazilian patients. Subjects and methods:, Sixty-two consecutive subjects affected by minor and major forms of RAS and 62 healthy volunteers were genotyped at IL-1, (+3954). The chi-squared test was used for statistical analysis. Results:, A significant increase in the high production of IL-1, genotype CT was observed in the group with RAS (P = 0.01). After stratifying RAS patients according to the mean number of lesions per episode, a significant difference was only observed between patients with ,3 lesions in each episode and control. Conclusion:, There is an increased frequency of polymorphism associated with high IL-1, production in RAS patients. [source] The Influence of Knowledge Accumulation on Buyer-Supplier Codevelopment ProjectsTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 5 2003Melissa M. Appleyard This article investigates innovation across a supply chain and considers how knowledge accumulation as a consequence of buyer-supplier codevelopment projects can influence the projects' specifications. The setting is the semiconductor industry, and the players are chip producers who cooperate with their suppliers to modify their manufacturing equipment used to produce new semiconductor devices. Two detailed case studies were undertaken to determine the tradeoffs encountered by the buyer and supplier when setting the parameters that govern codevelopment projects. The findings from the case studies inform a conceptual framework that outlines the net payoffs to buyers when deciding whether to "make" or "buy" their production equipment. If buyers pursue the "make" option, they then have to decide the degree to which they sponsor modifications tailored to their production processes or modifications more generally applicable across the industry. More generally applicable modifications likely would prompt suppliers to invest relatively more in follow-on knowledge creation for upgrades and field support while leading to lower equipment costs due to economies of scale from larger production runs of the new equipment. The framework suggests that when making this sequence of decisions, an innovative buyer also weighs the importance of codevelopment for securing intellectual property rights, guaranteeing early access to new equipment enabling early product launch, and achieving high production yields quickly due to "previewing" the equipment. The conceptual framework leads to a multi-period model that focuses on the importance of knowledge accumulation for project parameterization. As captured by the model, buyers may prefer generally applicable modifications to customized ones, because generally applicable modifications may lead to greater knowledge accumulation at the supplier. This knowledge accumulation may be either "embodied" in equipment upgrades or "unembodied" in improved field support. In addition to shaping the nature of particular codevelopment projects, knowledge accumulation also may have profound implications for long-run industry structure. As seen in the semiconductor industry, knowledge accumulation at equipment suppliers has contributed to the rise of contract manufacturers, because these manufacturers can outfit their production facilities with equipment that embodies the accumulated knowledge. These findings suggest that for both short-run and long-run reasons, the dynamics of knowledge accumulation merit thorough attention when members of a supply chain cooperate during the course of new product development. [source] Synthesis of New Quinoline Derivatives as Inhibitors of Human Tumor Cells GrowthARCHIV DER PHARMAZIE, Issue 8 2010Aymn E. Rashad Abstract A series of new 8-[(2H -tetrazol-5-yl)methoxy]quinoline derivatives, their sugar hydrazones, and their N -glycoside derivatives were synthesized. Furthermore, the 1,2,4-triazole-3-one derivatives 3 and 4 were synthesized from the amidrazone derivative 2. Some of the newly prepared compounds demonstrated inhibitory effects on the growth of MCF-7 human breast cancer cells as compared with the activity of the commonly used anticancer drug, cisplatin. The results of antitumor evaluation revealed that compounds 2,5, 8b, and 12 inhibited the growth of cancer cells through their effect as free-radical regulators by increasing the activity of superoxide dismutase and depletion of intracellular levels of reduced glutathione, catalase and glutathione peroxidase activities, accompanied with a high production of hydrogen peroxide, nitric oxide, and other free radicals causing the killing of tumor cells. The results suggested that the prepared compounds possess significant anticancer activity comparable to cisplatin and the antitumor activity of these prepared compounds was accompanied with a reduction in the levels of protein and nucleic acids. [source] Macrophage migration inhibitory factor promoter polymorphisms and the clinical expression of sclerodermaARTHRITIS & RHEUMATISM, Issue 11 2006Sou-Pan Wu Objective To investigate the potential association between functional polymorphisms in the gene for the innate mediator, macrophage migration inhibitory factor (MIF), and the clinical expression of systemic sclerosis (SSc). Methods Genomic DNA samples and clinical data were collected from the Scleroderma Family Registry and DNA Repository at the University of Texas Health Science Center at Houston. A total of 740 subjects were studied; 203 of them had diffuse cutaneous SSc (dcSSc), 283 had limited cutaneous SSc (lcSSc), and the remaining 254 healthy subjects served as controls. Association analyses were performed on the whole data set and on patient and sex subsets. Significant relationships were determined between clinical variables and MIF polymorphisms for each disease subtype in the studied groups. Results The frequency of the ,173*C MIF allele, which was previously reported to be associated with high production of MIF, was lower in the lcSSc group (12.6%) than in the dcSSc (19.2%) or control (18.5%) groups (P = 0.010 and P = 0.011, respectively). Haplotype analysis for 2 closely linked polymorphisms in the MIF promoter showed that in white subjects with lcSSc or dcSSc, the lcSSc population had a significantly lower representation of the high-expression MIF haplotype defined by ,173*C and ,794 with 7 CATT repeats (C7) (P = 0.015, odds ratio 1.94 [95% confidence interval 1.14,3.32]). Fibroblasts encoding the C7 MIF haplotype were observed to produce more MIF upon in vitro stimulation than those with a non-C7 haplotype. Conclusion Functional promoter polymorphisms in the MIF gene affect the clinical presentation of SSc. The proinflammatory haplotype defined by C7 is underrepresented in patients with lcSSc. [source] Record of sea-level fall in tropical carbonatesBASIN RESEARCH, Issue 2 2009Wolfgang Schlager ABSTRACT Stratigraphic forward modeling and comparison with published case studies have been used to determine the controls and stability domains of two conceptual models concerning relative sea-level fall in carbonate sequence stratigraphy. In the standard model, deposition occurs principally during rise and stillstands of relative sea level; a continuous erosional unconformity develops during sea-level fall. The falling-stage systems tract model (FST) postulates significant deposition during sea-level fall. Sedimentological principles, numerical models and published case studies of tropical carbonate sequences indicate that presence or absence of FST is not simply a function of the rate of sea-level fall but depends on the balance of the rates of erosion, sea-level fall and carbonate production, whereby the FST is favoured by high production, slow erosion and slow sea-level fall. Case studies plotted in the parameter space spanned by these variables support the modeling results. The ranges of rates required for the FST in the modeling runs are common in the geologic record. Consequently, the FST can be expected to be more common in tropical carbonate rocks than published records, particularly seismic data, currently indicate. [source] Biometrical evidence for adaptations of the salivary glands to pollen feeding in Heliconius butterflies (Lepidoptera: Nymphalidae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2009STEFAN H. EBERHARD The Neotropical genus Heliconius (Nymphalidae) is unique among butterflies for its pollen-feeding behaviour. With the application of saliva, they extract amino acids from pollen grains on the outside of the proboscis. We predicted that the salivary glands of pollen-feeding Heliconiinae would show adaptations to this derived feeding behaviour. A biometrical analysis of the salivary glands revealed that pollen-feeding butterflies of the genus Heliconius have disproportionately longer and more voluminous salivary glands than nonpollen-feeding Nymphalidae. The first two components in the principal component analysis explained approximately 95% of the total variance. The size-dependent factor score coefficients of body length and salivary gland parameters were predominately represented on axis 1. They significantly discriminated pollen-feeding from nonpollen-feeding heliconiines on that axis. Factor score coefficients for the volume of the secretory region of the salivary glands separated heliconiines from the outgroup species. The detailed biometrical analysis of salivary glands features thus provides strong evidence that the secretory regions of the salivary glands are larger in pollen-feeding butterflies. We concluded that pollen feeding is associated with a high production of salivary fluid. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 604,612. [source] Kinetic characterization of vero cell metabolism in a serum-free batch culture processBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2010Emma Petiot Abstract A global kinetic study of the central metabolism of Vero cells cultivated in a serum-free medium is proposed in the present work. Central metabolism including glycolysis, glutaminolysis, and tricarboxylic acid cycle (TCA) was demonstrated to be saturated by high flow rates of consumption of the two major substrates, glucose, and glutamine. Saturation was reavealed by an accumulation of metabolic intermediates and amino acids, by a high production of lactate needed to balance the redox pathway, and by a low participation of the carbon flow to the TCA cycle supply. Different culture conditions were set up to reduce the central metabolism saturation and to better balance the metabolic flow rates between lactate production and energetic pathways. From these culture conditions, substitutions of glutamine by other carbon sources, which have lower transport rates such as asparagine, or pyruvate in order to shunt the glycolysis pathway, were successful to better balance the central metabolism. As a result, an increase of the cell growth with a concomitant decrease of cell death and a better distribution of the carbon flow between TCA cycle and lactate production occurred. We also demonstrated that glutamine was a major carbon source to supply the TCA cycle in Vero cells and that a reduction of lactate production did not necessary improve the efficiency of the Vero cell metabolism. Thus, to adapt the formulation of the medium to the Vero cell needs, it is important to provide carbon substrates inducing a regulated supply of carbon in the TCA cycle either through the glycolysis or through other pathways such as glutaminolysis. Finally, this study allowed to better understand the Vero cell behavior in serum-free medium which is a valuable help for the implementation of this cell line in serum-free industrial production processes. Biotechnol. Bioeng. 2010;107: 143,153. © 2010 Wiley Periodicals, Inc. [source] Inhibition of LPS-induced chemokine production in human lung endothelial cells by lipid conjugates anchored to the membraneBRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2002G Ch Beck In acute respiratory distress syndrome (ARDS) induced by endotoxins, a high production of inflammatory mediators by microvascular lung endothelial cells (LMVEC) can be observed. Activation of cells by endotoxins may result in elevated secretion of phospholipase A2 (sPLA2) which is thought to contribute to tissue damage. The present study was undertaken to investigate the role of sPLA2 in chemokine production in human lung microvascular endothelial cells (LMVEC) stimulated with the endotoxins lipopolysaccharide (LPS) and lipoteichoic acid (LTA). In particular, we investigated the effects of sPLA2 inhibitors, specifically, the extracellular PLA2 inhibitors (ExPLIs), composed of N-derivatized phosphatidyl-ethanolamine linked to polymeric carriers, and LY311727, a specific inhibitor of non-pancreatic sPLA2. ExPLIs markedly inhibited LPS and LTA induced production and mRNA expression of the neutrophile attracting chemokines IL-8, Gro-, and ENA-78, as well as of the adhesion molecules ICAM-1 and E-selectin. Concomitantly, ExPLIs inhibited the LPS-induced activation of NF-,B by LPS but not its activation by TNF-, or IL-1. Endotoxin mediated chemokine production in LMVEC seems not to involve PLA2 activity, since LPS stimulation was not associated with activation of intracellular or secreted PLA2. It therefore seems that the inhibitory effect of the ExPLIs was not due to their PLA2 inhibiting capacity. This was supported by the finding that the LPS-induced chemokine production was not affected by the selective sPLA2 inhibitor LY311727. It is proposed that the ExPLIs may be considered a prototype of potent suppressors of specific endotoxin-induced inflammatory responses, with potential implications for the therapy of subsequent severe inflammation. British Journal of Pharmacology (2002) 135, 1665,1674; doi:10.1038/sj.bjp.0704618 [source] | |||||||||||||||||||