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Strandberg, Per Erik. "Mathematical models of bacteria population growth in bioreactors: formulation, phase space pictures, optimisation and control." Thesis, Linköping University, Department of Mathematics, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2337.
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There are many types of bioreactors used for producing bacteria populations in commercial, medical and research applications.
This report presents a systematic discussion of some of the most important models corresponding to the well known reproduction kinetics such as the Michaelis-Menten kinetics, competitive substrate inhibition and competitive product inhibition. We propose a modification of a known model, analyze it in the same manner as known models and discuss the most popular types of bioreactors and ways of controlling them.
This work summarises much of the known results and may serve as an aid in attempts to design new models.
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Rorrer, Rebecca Kathleen. "Veterinary Therapeutic and Biologic Agents in Virginia Sheep Production." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34574.
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Biological and therapeutic agents are used in food animal production to maintain animal health and well being, prevent and treat disease, and to maintain or enhance production. Concerns about the use of pharmaceutical agents in food animal production have been raised, especially in relation to food quality and safety. This study addressed the scarcity of information concerning the quantity of pharmaceuticals being used and the reasons for their use in sheep production. Additional goals included determining the sources of information used by shepherds in making treatment decisions and evaluating the economic impact that pharmaceutical usage has on sheep production. Thirty-nine Virginia sheep producers participated in this study of four months duration from March through September. After completing an initial questionnaire to determine flock and management characteristics, participants were asked to record all treatments with biological and therapeutic agents that occurred within their sheep flocks. A total of 14,310 treatments were recorded for a median of 1.5 treatments per sheep per month. Parasite control and vaccination were the most frequent reasons for treatment (64.9% and 15.2%, respectively) with vitamin/mineral supplementation being the next most common (8.8%). Price information was collected for 13,912 treatment events. An estimated total of $7,523.78 was spent on pharmaceutical treatment over the course of the study. This amounts to a cost of $0.63 per sheep per month of observation. Results of this study will enhance the ability of producers to evaluate treatment decisions, allow comparisons to be made between operations and provide a base of information for future research.Master of Science
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Wachtel, Heather. "Polymorphisms and Biologic Effects of Acidic Mammalian Chitinase in Asthma." Yale University, 2009. http://ymtdl.med.yale.edu/theses/available/etd-03102009-162717/.
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In this study, we hypothesize that human acidic mammalian chitinase (AMCase) binds and is regulated by the epidermal growth factor receptor (EGFR), and that AMCase interacts with Galectin-3 (Gal-3) to mediate anti-apoptotic functions. We further hypothesize that asthma-associated polymorphisms of AMCase alter chitinase activity and modulate anti-apoptotic effects. We investigated the interactions between AMCase, Gal-3 and EGFR by establishing binding and co-expression in vitro; apoptotic effects were evaluated via Annexin V/Propidium Iodide staining. Molecular cloning was performed to generate single nucleotide polymorphisms (SNPs) of AMCase associated with asthma. Our data showed that co-expression of AMCase and EGFR induces chitinase activity; we found that AMCase and Gal-3 bind each other in vitro, and that they co-localize in the cytoplasm of cells. Co-transfection of AMCase and Gal-3 demonstrates greater anti-apoptotic effect than Gal-3 alone, while recombinant Gal-3 induces apoptosis, which is not blocked by incubation with recombinant AMCase. From these data, we conclude that AMCase is regulated by EGFR, and that AMCase and Gal-3 physically interact, however contrary to our hypothesis, the anti-apoptotic effects of AMCase are unlikely to be mediated by Gal-3. Further exploration of this pathway using SNP constructs generated in this study will shed light on the mechanism of AMCase in asthma.
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Robinson, Stephen D. "The Historical Production of Elemental Phosphorus in Pinellas County, Florida: An Environmental Assessment." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002075.
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Gustafsson, Pär. "Forest-stream linkages : Experimental studies of foraging and growth of brown trout (Salmo trutta L)." Licentiate thesis, Karlstad University, Faculty of Social and Life Sciences, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1649.
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Riparian vegetation along streams and rivers affects the aquatic community in numerous ways and often operates as a link for energy flux between forest and streams. The studies presented in this licentiate thesis focus on light and terrestrial invertebrates, two factors influenced by riparian zone structure, which potentially affect stream ecosystems and thus also brown trout (Salmo trutta). Paper I is a laboratory experiment where I study size dependent foraging behavior on surface-drifting terrestrial invertebrates and benthic invertebrates by brown trout. The results show a size-dependent difference in foraging ability with large trout being better able to use terrestrial surface prey than small trout. I argue that such ontogenetic foraging differences are due to both morphological constraints (eg. gape limitation) and size dependent behavioral differences related to predation risk. Paper II consists of a 5 month-long 2x2 factorial design field experiment where my objective was to examine the effects of terrestrial invertebrate input and solar radiation (PAR) on different trophic levels in a boreal headwater stream. More specifically, I followed the effects of increased light and decreased terrestrial invertebrate subsidies on periphyton, benthic macroinvertebrates and two size classes of the top fish predator, brown trout. The results showed that the reduction of terrestrial invertebrate input had size- and seasonal-dependent effects on trout, where large trout had lower growth rates than small trout, mainly in summer. Diet analyses of trout supported growth differences in that large trout in unmanipulated enclosures consumed relatively more terrestrial prey than large trout living in enclosures with reduced terrestrial inputs. A higher reliance on terrestrial prey subsidies by large trout compared to small may be explained by ontogenetic differences in foraging and habitat choice. Despite a 2.5-fold increase in PAR, light did not have an effect on chlorophyll a biomass, nor was there an effect on the density or composition of benthic macroinvertebrates. The lack of effects on primary production may be explained by very low nutrient levels in the stream.
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Takaba, Kiyoaki. "A combination of omental flap and growth factor therapy induces arteriogenesis and increases myocardial perfusion in chronic ischemic myocardium : evolving concept of biologic coronary artery bypass grafting." Kyoto University, 2007. http://hdl.handle.net/2433/135664.
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Davies, Oluwafemi. "Recombinant protein production in the chloroplast of microalgae : a systems biology approach." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/recombinant-protein-production-in-the-chloroplast-of-microalgae-a-systems-biology-approach(fe23d3a0-a882-48e0-8171-53cc05225db2).html.
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Several expression systems for recombinant protein production, essentially cells or whole organisms are currently in use today. Recently, research into recombinant protein production revealed a more attractive expression system based on the microalgae, C. reinhardtii, for significant savings in cost and production of correctly folded recombinant proteins. However, protein yield in the microalgae remain very low, non-predictable and whether this was due to limitations in the system was unclear. Using the expression of E. coli β-glucuronidase (gus) in C. reinhardtii chloroplast, the overall aim of the project was to address if the low recombinant gus yield in C. reinhardtii was due to limitations that affect growth and protein production, and if the fluxes for recombinant gus production were suboptimal (limiting). The finding was used to implement a strategy for a more predictable recombinant protein yield in C. reinhardtii. The research involved a range of experiments, analysis, and Flux Balance Analysis (FBA) modelling. The growth of C. reinhardtii cultures were characterized in autotrophic, heterotrophic and mixotrophic conditions to identify factors that limit growth and recombinant gus yields. These factors were availability of light, carbon and nitrogen substrates, pH changes, protein burden and energetic limitation (ATP). The highest biomass was obtained in autotrophic and mixotrophic cultures (>1 g/litre), the lowest biomass was in heterotrophic cultures (~0.4 g/litre). The recombinant gus yields on the basis of dry cell weight were: mixotrophic cultures (0.038%), autotrophic cultures (0.032%), heterotrophic cultures (0.026%). No detectable protein burden was observed for expression of recombinant gus in autotrophic and mixotrophic conditions, but protein burden was significant in heterotrophic condition (15 – 18% reduction in growth rate). A strategy that significantly increased growth and cell productivity (>3 fold) in heterotrophic condition was identified. FBA was used to identify suboptimal amino acid steady state fluxes (bottlenecks) that limited the gus yield. Using FBA modelling, model verifications and corrections, a strategy that significantly increased the yield of recombinant gus in each cell (~2 fold) was identified. Put together, the total increase represents a 6 fold increase in recombinant gus yield. Furthermore, this research presented a framework for identifying, analysing and understanding the effect of the uptake of individual amino acid towards recombinant protein yield.
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Boutros, Tarek. "Interferon-beta is a potent promoter of nerve growth factor production by astrocytes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0005/MQ37098.pdf.
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Pinna, Adriano. "Modelling growth dynamics and toxin production in Ostreopsis cf. ovata." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6763/.
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The benthic dinoflagellate O. ovata represents a serious threat for human health and for the ecology of its blooming areas: thanks to its toxicity this microalga has been responsible for several cases of human intoxication and mass mortalities of benthic invertebrates. Although the large number of studies on this dinoflagellate, the mechanisms underpinning O. ovata growth and toxin production are still far to be fully understood. In this work we have enriched the dataset on this species by carrying out a new experiment on an Adriatic O. cf. ovata strain. Data from this experiment (named Beta) and from another comparable experiment previously conducted on the same strain (named Alpha), revealed some interesting aspects of this dinoflagellate: it is able to grow also in a condition of strong intracellular nutrient deficiency (C:P molar ratio > 400; C:N > 25), reaching extremely low values of chlorophyll-a to carbon ratio (0.0004). Was also found a significant inverse relationships (r > -0.7) between cellular toxin to carbon and cellular nutrient to carbon ratios of experiment Alpha. In the light of these result, we hypothesized that in O. cf. ovata nutrient-stress conditions (intended as intracellular nutrient deficiency) can cause: i) an increase in toxin production; ii) a strong decrease in chlorophyll-a synthesis; iii) a lowering of metabolism associated with the formation of a sort of resting stage. We then used a modelling approach to test and critically evaluate these hypotheses in a mechanistic way: newly developed formulation describing toxin production and fate, and ad hoc changes in the already existent formulations describing chlorophyll synthesis, rest respiration, and mortality, have been incorporated in a simplified version of the European Regional Seas Ecosystem Model (ERSEM), together with a new ad hoc parameterization. The adapted model was able to accurately reproduce many of the trends observed in the Alpha experiment, allowing us to support our hypotheses. Instead the simulations of the experiment Beta were not fully satisfying in quantitative terms. We explained this gap with the presumed different physiological behaviors between the algae of the two experiments, due to the different pre-experimental periods of acclimation: the model was not able to reproduce acclimation processes in its simulations of the experiment Beta. Thus we attempt to simulate the acclimation of the algae to nutrient-stress conditions by manual intervention on some parameters of nutrient-stress thresholds, but we received conflicting results. Further studies are required to shed light on this interesting aspect. In this work we also improve the range of applicability of a state of the art marine biogeochemical model (ERSEM) by implementing in it an ecological relevant process such as the production of toxic compounds.
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Çebi, Zehra [Verfasser], Michael [Gutachter] Melkonian, and Burkhard [Gutachter] Becker. "Efficient microscale screening of various Haematococcus pluvialis strains for growth and astaxanthin production / Zehra Çebi ; Gutachter: Michael Melkonian, Burkhard Becker." Köln : Universitäts- und Stadtbibliothek Köln, 2017. http://d-nb.info/1138027219/34.
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Wang, Hao-Ching. "Role of tobacco anionic peroxidase on plant growth and development and the effect on endogenous auxin production /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu148639447597754.
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Hufford, Kathy (Kathy E. ). "Comparison of the growth and monoclonal antibody production of suspended mammalian cells in three perfusion systems." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39921.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Biological Engineering Division, 2007.Includes bibliographical references (leaves 139-141).
The purpose of this thesis was to provide a broad survey of bioprocess options for typical drug production vehicles in the biotechnology industry. This goal was accomplished by comparing the growth and monoclonal antibody production by HPCHO Chinese hamster ovary cells and IB4 hybridoma cells in batch, fed-batch, and three perfusion systems: the stirred ceramic membrane reactor (SCMR), the alternating tangential flow (ATF) hollow fiber membrane system, and the external spin filter (ESF) system. The batch experiments for each cell line were used as base case scenarios for the comparisons of cell growth and monoclonal antibody production. The fed-batch experiments for each cell line did not vastly improve the cell growth and monoclonal antibody production over the batch cases. The SCMR perfusion system greatly improved the cell growth and monoclonal antibody production for each cell line. The maximum viable cell concentration of the IB4 hybridoma cells in the SCMR experiment was over seven times that found in the batch experiment and the monoclonal antibody production in the SCMR experiment was over ten times that found in the batch experiment.
(cont.) The ATF perfusion system greatly increased the cell growth for each cell line over the batch cases, but the shear forces created by the system adversely affected the viability of the cells and the monoclonal antibody production was less than that of the SCMR experiments. The ESF perfusion system damaged the HPCHO Chinese hamster ovary cells. For the production of the IB4 hybridoma cells, the ESF system, as well as a modified ESF system, did not vastly improve the cell growth and monoclonal antibody over the base case due to cell aggregation and filter fouling. The cell growth and productivity data, along with economic considerations, were evaluated for the purpose of recommending the best feeding strategy for each of the two cell lines studied. It was concluded that the most successful operation mode for the two cell lines studied was the SCMR perfusion system. More research is needed regarding the scale-up ramifications of the SCMR perfusion system as well as in the quantification of monoclonal antibodies, the optimization of fed-batch systems, and the use of alternative perfusion systems.
by Kathy Hufford.
M.Eng.
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Countway, Peter Dylan. "Carbon Production and Growth Physiology of Heterotrophic Bacteria in a Subtropical Coral Reef Ecosystem." W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539617745.
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Baitan, Daniela-Paraschiva [Verfasser], and Christian [Akademischer Betreuer] Betzel. "Analyzing Crystal Growth Phenomena and Mechanisms for the Production and Optimization of Protein Crystals for Serial Crystallography / Daniela-Paraschiva Baitan ; Betreuer: Christian Betzel." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2018. http://d-nb.info/1170872999/34.
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Iqbal, Qaiser. "Quantification of fungal biomass growth during citric acid production by «Aspergillus niger» on expanded clay solid substrate." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19292.
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The growth of fungi on sugar rich wastes can be an economical way of producing citric acid. Nevertheless, conditions for the optimum production of citric acid still need to be established. Using Aspergillus niger, the objective of the present study was to measure the effect on citric acid accumulation and fungal biomass, of sugar and nitrogen supplementation namely as glucose and ammonium, respectively. An inert solid substrate (Hydroton® or HSS) made of expanded clay and wetted with a nutrient solution was used to grow A. niger ATCC12846 and measure its fungal biomass with fermentation time. Citric acid accumulation and fungal biomass were measured during 168 h of fermentation with glucose concentrations ranging 0 to 475 g (kg HSS)-1 and ammonium ranging from 2 to 16 g (kg HSS)-1. Fungal biomass growth was monitored by measuring the change of total volatile solids (TVS) less residual glucose and citric acid, and; organic nitrogen accumulation. Glucose and ammonium had a significant effect (P < 0.10) on both fungal biomass and citric acid accumulation. For citric acid, the highest concentration of 52 g and yield of 14% were obtained with 475 and 250 g glucose (kg HSS)-1 and 8 g of N (kg HSS)-1. Nevertheless, only the glucose concentration of 475 g (kg HSS)-1 resulted in citric acid accumulation continuing after reaching a peak in fungal biomass. This high glucose concentration could have yielded more citric acid by using a pH of 5.5 during spore germination and of 2.0 during fungal biomass growth. Because the C:N ratio of the fungal biomass was observed to vary with nitrogen supplementation, it is not recommended to use organic N to quantify fungal biomass.La fermentation de champignons sur des résidus riches en sucre pourrait être une façon économique de produire de l'acide citrique, à condition de bien maîtriser les paramètres de fermentation. La présente étude avait comme objectif d'évaluer l'effet de la charge de sucre, soit en glucose, et d'azote, soit en ammonium, sur la biomasse du champignon Aspergillus niger ATCC12846 et sur sa production d'acide citrique. De l'argile expansée (Hydrotron® ou HSS) fut utilisée comme substrat solide pour le champignon A. niger ATCC 12846. Le substrat fut humecté d'une solution offrant différents taux de glucose, de 0 à 475 g (kg HSS)-1 et d'azote sous forme d'ammonium, de 2 à 16 g (kg HSS)-1. La biomasse fongique fut obtenue en mesurant la masse volatile totale moins la masse résiduelle de glucose et la masse d'acide citrique, et; l'augmentation de la masse d'azote organique. Le taux de glucose et d'ammonium a eu un effet significatif sur la biomasse fongique et la production d'acide citrique pendant les 168 h de fermentation. Une concentration en glucose de 475 et 250 g (kg HSS)-1 maximisaient la concentration de 52 g (kg HSS)-1 et le rendement de 14% en acide citrique, respectivement, avec 8g d'azote (kg HSS)-1. Par contre, seulement la concentration en glucose de 475 g (kg HSS)-1 permettait d'accumuler de l'acide citrique après avoir atteint le plus de biomasse. Un rendement supérieur exigerait un meilleur contrôle du pH à 5.5 pendant le développement des spores et à 2.0 pendant la fermentation. Puisque le ratio C:N de la biomasse fluctuait avec la concentration d'azote dans la solution, il n'est pas recommandé d'utiliser l'azote organique pour suivre l'évolution de la biomasse.
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Burberg, Christian [Verfasser], Elert Eric [Gutachter] von, and Michael [Gutachter] Bonkowski. "The effects of environmental conditions on growth and protease inhibitor production of the cyanobacterium Microcystis aeruginosa / Christian Burberg ; Gutachter: Eric von Elert, Michael Bonkowski." Köln : Universitäts- und Stadtbibliothek Köln, 2020. http://d-nb.info/1232404497/34.
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Sathish, Ashik. "Biodiesel Production from Mixed Culture Algae Via a Wet Lipid Extraction Procedure." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1372.
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With world crude oil reserves decreasing and energy prices continually increasing, interest in developing renewable alternatives to petroleum-based liquid fuels has increased. An alternative that has received consideration is the growth and harvest of microalgae for the production of biodiesel via extraction of the microalgal oil or lipids. However, costs related to the growth, harvesting and dewatering, and processing of algal biomass have limited commercial scale production of algal biodiesel. Coupling wastewater remediation to microalgal growth can lower costs associated with large scale growth of microalgae. Microalgae are capable of assimilating inorganic nitrogen and phosphorous from wastewater into the biomass. By harvesting the microalgal biomass these nutrients can be removed, thus remediating the wastewater. Standard methods of oil extraction require drying the harvested biomass, adding significant energetic cost to processing the algal biomass. Extracting algal lipids from wet microalgal biomass using traditional methods leads to drastic reductions in extraction efficiency, driving up processing costs. A wet lipid extraction procedure was developed that was capable of extracting 79% of the transesterifiable lipids from wet algal biomass (16% solids) without the use of organic solvents while using relatively mild conditions (90 °C and ambient pressures). Ultimately 77% of the extracted lipids were collected for biodiesel production. Furthermore, the procedure was capable of precipitating chlorophyll, allowing for the collection of algal lipids independently of chlorophyll. The capability of this procedure to extract lipids from wet algal biomass, to reduce chlorophyll contamination of the algal oil, and to generate feedstock material for the production of additional bio-products provides the basis for reducing scale-up costs associated with the production of algal biofuels and bioproducts.
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Akintunde, Olaitan G. "Production of an Antibiotic-like Activity by Streptomyces sp. COUK1 under Different Growth Conditions." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etd/2412.
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Streptomyces are known to produce a large variety of antibiotics and other bioactive compounds with remarkable industrial importance. Streptomyces sp. COUK1 was found as a contaminant on a plate in which Rhodococcus erythropolis was used as a test strain in a disk diffusion assay and produced a zone of inhibition against the cultured R. erythropolis. The identity of the contaminant was confirmed as Streptomyces through 16S rRNA sequencing. This Streptomyces produces a strong inhibitory compound in different growth media. A culture extract from inorganic salts starch agar was found to be very active; producing a large zone of inhibition against several Gram positive and Gram negative test strains. The active molecules in this extract have been detected via TLC and bioautography. The difference in the antibacterial activity and chromatographic properties of extracts recovered from different growth media suggests that this Streptomyces strain could produce more than one type of inhibitory compound.
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Bäcklund, Emma. "Impact of glucose uptake rate on recombinant protein production in Escherichia coli." Doctoral thesis, KTH, Bioprocessteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34019.
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Escherichia coli (E. coli) is an attractive host for production of recombinant proteins, since it generally provides a rapid and economical means to achieve high product quantities. In this thesis, the impact of the glucose uptake rate on the production of recombinant proteins was studied, aiming at improving and optimising production of recombinant proteins in E. coli. E. coli can be cultivated to high cell densities in bioreactors by applying the fed-batch technique, which offers a means to control the glucose uptake rate. One objective of this study was to find a method for control of the glucose uptake rate in small-scale cultivation, such as microtitre plates and shake flasks. Strains with mutations in the phosphotransferase system (PTS) where used for this purpose. The mutants had lower uptake rates of glucose, resulting in lower growth rates and lower accumulation of acetic acid in comparison to the wild type. By using the mutants in batch cultivations, the formation of acetic acid to levels detrimental to cell growth could be avoided, and ten times higher cell density was reached. Thus, the use of the mutant strains represent a novel, simple alternative to fed-batch cultures. The PTS mutants were applied for production of integral membrane proteins in order to investigate if the reduced glucose uptake rate of the mutants was beneficial for their production. The mutants were able to produce three out of five integral membrane proteins that were not possible to produce by the wild-type strain. The expression level of one selected membrane protein was increased when using the mutants and the expression level appeared to be a function of strain, glucose uptake rate and acetic acid accumulation. For production purposes, it is not uncommon that the recombinant proteins are secreted to the E. coli periplasm. However, one drawback with secretion is the undesired leakage of periplasmic products to the medium. The leakage of the product to the medium was studied as a function of the feed rate of glucose in fed-batch cultivations and they were found to correlate. It was also shown that the amount of outer membrane proteins was affected by the feed rate of glucose and by secretion of a recombinant product to the periplasm. The cell surface is another compartment where recombinant proteins can be expressed. Surface display of proteins is a potentially attractive production strategy since it offers a simple purification scheme and possibilities for on-cell protein characterisation, and may in some cases also be the only viable option. The AIDA-autotransporter was applied for surface display of the Z domain of staphylococcal protein A under control of the aidA promoter. Z was expressed in an active form and was accessible to the medium. Expression was favoured by growth in minimal medium and it seemed likely that expression was higher at higher feed rates of glucose during fed-batch cultivation. A repetitive batch process was developed, where relatively high cell densities were achieved whilst maintaining a high expression level of Z.QC 20110608
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de, Paula Reis Alline. "Conception biologique complexe : Planification et modèles d'affaires. Le cas du clonage équin. Conception et planification dans les biotechnologies innovantes : le clonage équin." Thesis, Paris, AgroParisTech, 2013. http://www.theses.fr/2013AGPT0076.
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Les sciences du vivant ont connu des développements technologiques importants dans les dernières décennies. Dans les années 90 et 2000 le monde a assisté à l'apparition de plusieurs technologies a priori prometteuses telles que le clonage de mammifères, la transgénèse animale et végétale ou encore les traitements thérapeutiques par des cellules souches. La littérature spécialisée dans le domaine est riche en publications sur les aspects technico-expérimentaux de ces technologies et, malgré la difficulté technique encore apparente dans les publications, les auteurs sont optimistes quant à la réalisation de ces technologies de façon commerciale. Ces avancées technologiques se sont accompagnées de l'émergence d'une nouvelle industrie du vivant. Les entreprises de ce nouvel environnement sont rapidement reconnaissables par leur besoin intensif de connaissance, leur haut niveau de spécialisation et des compétences hautement spécialisées. Mais, malgré ce caractère innovant, et le développement d'un nouveau marché à haute valeur ajoutée, les entreprises qui se lancent sur ces activités sont fréquemment affrontées à des difficultés économiques. Nous avons souhaité analyser cette nouvelle industrie du point de vue gestionnaire afin de comprendre les difficultés de gestion rencontrées par les acteurs. La littérature académique et empirique traite peu les questions managériales de ces technologies. Généralement, chaque technologie y est traitée de façon très individualisée de façon à ce que chaque technologie soit reconnue comme une entité particulière, presque unique. Ce contexte engendre l'impossibilité d'avoir une vision unifiée et générique de ces industries. Nous avons alors proposé de concevoir un modèle générique permettant de discuter les caractéristiques managériales génériques de cette industrie. Cet effort de conceptualisation est utile dans un premier temps pour comprendre les difficultés de gestion rencontrées par les entreprises dédiées aux technologies récentes du domaine du vivant. Par la suite, le concept peut être utile pour la proposition d'améliorations managériales. La Théorie C-K a été mobilisée pour faciliter l'organisation des informations disponibles et les structurer de façon à en faire des connaissances mobilisables pour la conception du modèle générique souhaité. La collecte des informations a été réalisée à l'aide d'une étude de cas, telle que décrite par Eisenhardt (1989). Comme il existe une grande variété de technologies dans cette industrie, nous avons décidé de développer le concept à partir du cas d'une technologie spécialement touchée par les difficultés entrepreneuriales : celle du clonage équin. [...] Suite et fin du résumé dans la thèseLife sciences noticed important technological developments during the last decades. Some promising examples, developed in the 90's and 2000's, were mammals cloning, animal and vegetal transgenesis and the therapeutic stem cells. The specialized literature of the life science domain is rich on technical-experimental publications and despite the technical difficulty still present, the authors are optimistic about their commercial issue. These technological advances induced the emergence of a new life science industry where the companies are knowledge intensive and highly specialised. Despite the innovative character and the development of a new market of high added value, the companies of this sector often face economic difficulties. We analysed this recent industry under the managerial point of view aiming to understand the difficulties presented to the managers. Little concern about these problems is available in the specialised literature. In general the technologies are treated individually as an almost unique entity. Under this context it is currently impossible to develop a general overview enabling to study general aspects of this industry. In this aim we proceeded to design a generical model that could allow discussing the managerial characteristics of the industry. This designing effort was necessary to understand the general difficulties met by the companies specialised in these recent technologies. Thereafter the concept can be used to propose managerial improvements. The C-K Theory was employed to structure and translate available information in order to make them available for the design of the model. The data was collected under a case study methodology, as described by Eisenhardt (1989). The existence of a rich panel of recent technologies in this domain justifies the need to develop the concept from a unique extreme case, especially affected by managerial difficulties: the case of the equine cloning. Last and final summary in the thesis
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Han, Shengcai [Verfasser], and Martin [Akademischer Betreuer] Parniske. "Systemic responses of barley to the growth promoting, endophytic bacterium Acidovorax radicis N35 and role of 3-hydroxy-C10-homoserine lactone production in root colonization and plant perception / Shengcai Han ; Betreuer: Martin Parniske." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1127527916/34.
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Borkowski, Olivier. "Growth-rate-dependent protein production in bacteria." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05T004.
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Les théories actuelles suggèrent que l'efficacité de traduction (nombre de protéines produitespar ARN messager ; notion spécifique à chaque à gène) reste constante lorsque le taux decroissance varie. Néanmoins, une efficacité de traduction constante est incompatible avec lafaible corrélation observée, à l’échelle du génome, entre l’évolution en fonction du taux decroissance de la concentration des ARN messagers et des protéines pour lesquelles ils codent.Pour faire face à ce paradoxe, nous avons développé un modèle mathématique de la traductionbasé sur les connaissances actuelles de ce processus au niveau moléculaire. L’exploration despropriétés du modèle nous a amené à conduire des expériences de transcriptomique, de PCRquantitative et de Live Cell Array (LCA) dont l’analyse a montré que l'efficacité de traductiondiminue jusqu'à 4 fois entre faible et fort taux de croissance chez la bactérie modèle Bacillussubtilis. Notre modèle a révélé que la chute de l’efficacité de traduction repose sur une chutede la concentration des ribosomes libres. Pour étudier les conséquences de la chute desribosomes libres sur la production des protéines, nous avons rationnellement défini à partir dumodèle mathématique des constructions génétiques combinant des promoteurs, naturel ousynthétique, et différentes régions d'initiation de la traduction (TIRs) contrôlant l’expressiondu gène gfp. En utilisant ces constructions génétiques, nous avons montré que la productiondes protéines est non-linéaire en fonction de la concentration en ribosomes libres. Uneproduction non-linéaire entraine des efficacités de traduction différentielles des ARNmessagers en fonction de leurs TIRs. Ce mécanisme de régulation général des protéinesparticipe à la perte de corrélation entre la concentration des ARN messagers et des protéinescorrespondantes et nous a amené à revisiter la Physiologie Moléculaire BactérienneCurrent theories suggest that translation efficiency (i.e. number of proteins produced permRNA) remains invariant with increasing growth rate, which is inconsistent with the scanty correlation between mRNAs and cognate proteins abundances at the genome-scale level. We tackled this apparent paradox using a systems biology approach. We developed a knowledgebased, nonlinear mathematical model of translation. The in-depth analysis of the model led us to reassess experimentally, using high-throughput and genome-wide technologies, each measurable RNA entity at different growth rates. In contrast to the current knowledge, the total mRNA abundance was not constant but linearly increased with respect to the growth rate. A model-driven integration of genome-wide and molecular experimental datasets demonstrated that the drop in abundance of a constitutively expressed protein with increasing growth rate is not only due to the dilution but also to an unexpected up to 4-fold decrease of translation efficiency. Our model revealed that this drop relies on a drastic decrease in free (untranslating) ribosomes, a non-measurable entity. Using a set of 18 Bacillus subtilis strains combining 9 synthetic translation initiation regions (TIRs) and 2 constitutive promoters, we show that TIRs together with free ribosome abundance strongly contribute to a nonlinear modulation of single proteins as a function of the growth rate. The nonlinearity accounted for the loss of correlation between mRNAs and cognate proteins abundances. Altogether, our results evidenced a unique, hard-coded and global growth-rate-dependent regulation of single bacterial proteins without dedicated regulators
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Jaborek, Jerad R. "Use of Diverse Cattle Breeds to Understand Marbling Development and Growth for the Production of High-Quality Beef." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574348508186835.
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Beers, Emily N. "Investigating the Effects of Temperature on the Growth and Toxin Production of Saxitoxin, Anatoxin and Cylindropsermopsin-Producing Cyanobacteria." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1607677838514276.
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Backéus, Ingvar. "Aboveground production and growth dynamics of vascular bog plants in central Sweden." Uppsala : Stockholm : Svenska växtgeografiska sällskapet ; Almqvist & Wiksell International [distributor], 1985. http://catalog.hathitrust.org/api/volumes/oclc/12807002.html.
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De, Paula Reis Alline. "Conception biologique complexe : Planification et modèles d'affaires. Le cas du clonage équin." Phd thesis, AgroParisTech, 2013. http://pastel.archives-ouvertes.fr/pastel-01017382.
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Les sciences du vivant ont connu des développements technologiques importants dans les dernières décennies. Dans les années 90 et 2000 le monde a assisté à l'apparition de plusieurs technologies a priori prometteuses telles que le clonage de mammifères, la transgénèse animale et végétale ou encore les traitements thérapeutiques par des cellules souches. La littérature spécialisée dans le domaine est riche en publications sur les aspects technico-expérimentaux de ces technologies et, malgré la difficulté technique encore apparente dans les publications, les auteurs sont optimistes quant à la réalisation de ces technologies de façon commerciale. Ces avancées technologiques se sont accompagnées de l'émergence d'une nouvelle industrie du vivant. Les entreprises de ce nouvel environnement sont rapidement reconnaissables par leur besoin intensif de connaissance, leur haut niveau de spécialisation et des compétences hautement spécialisées. Mais, malgré ce caractère innovant, et le développement d'un nouveau marché à haute valeur ajoutée, les entreprises qui se lancent sur ces activités sont fréquemment affrontées à des difficultés économiques. Nous avons souhaité analyser cette nouvelle industrie du point de vue gestionnaire afin de comprendre les difficultés de gestion rencontrées par les acteurs. La littérature académique et empirique traite peu les questions managériales de ces technologies. Généralement, chaque technologie y est traitée de façon très individualisée de façon à ce que chaque technologie soit reconnue comme une entité particulière, presque unique. Ce contexte engendre l'impossibilité d'avoir une vision unifiée et générique de ces industries. Nous avons alors proposé de concevoir un modèle générique permettant de discuter les caractéristiques managériales génériques de cette industrie. Cet effort de conceptualisation est utile dans un premier temps pour comprendre les difficultés de gestion rencontrées par les entreprises dédiées aux technologies récentes du domaine du vivant. Par la suite, le concept peut être utile pour la proposition d'améliorations managériales. La Théorie C-K a été mobilisée pour faciliter l'organisation des informations disponibles et les structurer de façon à en faire des connaissances mobilisables pour la conception du modèle générique souhaité. La collecte des informations a été réalisée à l'aide d'une étude de cas, telle que décrite par Eisenhardt (1989). Comme il existe une grande variété de technologies dans cette industrie, nous avons décidé de développer le concept à partir du cas d'une technologie spécialement touchée par les difficultés entrepreneuriales : celle du clonage équin. [...] Suite et fin du résumé dans la thèse.
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Guha, Roy Aimee. "Microalgal growth and lipid production : trends, multiple regression models, and validation in a photobioreactor." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:282874c9-06d4-41bf-bdc9-fb4ff515f57c.
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Algae are a promising new source of oil for biodiesel. They are aquatic organisms that do not require cropland, and they can produce many useful side-products for bioenergy, aquaculture, and nutraceutical production. To be cost-effective, algae need high and reliable oil productivities; however, there is still a great deal to learn about the effects of culturing conditions on algae growth rates and lipid production. These culturing conditions include light intensity, gas flow, use of CO2, and culture volume. An extensive database of published research on algae growth rates and lipid contents under a wide variety of environmental conditions was prepared. By graphing data from 116 publications on 132 microalgae species, several key trends were identified relating to culturing parameters and algae biomass and lipid production. In addition, data from 131 publications on 128 microalgae species were graphed to look at presence of flagella, nutrient limitation, lipid productivity, and productivity tradeoffs. Moreover, cell size information was gathered for 146 species. The interactions between culture variables are complex, so it is difficult to quantify the degree to which each culture variable affects algae growth rates and lipid production. Therefore, several multivariate analyses were performed to generate a set of general and simple predictive models to assess specific growth rates, maximum lipid contents, and volumetric lipid productivities. These models were used to determine which culture parameters were significant predictors of algae growth rates and lipid production, and the contribution of each environmental parameter was quantified. In addition to models for algae in general, genera specific models were prepared for Chlorella, Isochrysis, Nannochloropsis, Phaeodactylum, and Tetraselmis. These models show high predictive capabilities, and they greatly extend the range of species-specific multiple regression models available. Furthermore, one Tetraselmis model was validated using Tetraselmis impellucida growth experiments in a large novel photobioreactor.
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Sevinc, Pelin. "Kinetic Analyses Of The Effects Of Temperature And Light Intensity On Growth, Hydrogenm Production And Organic Acid Utilization By Rhodobacter Capsulatus." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612195/index.pdf.
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Effects of temperature and light intensity on photofermentative hydrogen production by Rhodobacter capsulatus DSM1710 by use of acetic and lactic acids as substrates were studied. Experiments were conducted at 20, 30 and 38oC incubator temperatures under light intensities in the 1500 &ndash7000 lux range. pH of the medium and quantity of hydrogen forming together with quantity of biomass, and concentrations of acetic, lactic, formic, butyric and propionic acids in the medium were determined periodically. Growth took place and hydrogen was produced under all experimental conditions. Growth was found to increase with increase in temperature but to decrease with increase in light intensity. Total hydrogen produced increased with light intensity up to 6000 lux at 20oC, 5000 lux at 30oC and 3000 lux at 38oC and decreased beyond these values. Medium temperature of about 30oC was found to be optimum for cumulative hydrogen. pH was found to increase slightly and almost all of lactic acid and most of acetic acid was consumed while formic, butyric and propionic acids were first formed and then consumed in the experiments. Growth data fitted well to the logistic model and hydrogen production data fitted well to the Modified Gompertz Model. Lactic acid was found to be almost completely consumed by first order kinetics in early times. Consumption of acetic acid was found to follow zero order kinetics in the early times when lactic acid existed in the system but the order shifted to one later when most of lactic acid was consumed.
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Poola, Swetha Avula. "INFLUENCE OF DIET ON POPULATION GROWTH AND ALLERGEN PRODUCTION IN CULTURED HOUSE DUST MITES - DERMATOPHAGOIDES FARINAE AND DERMATOPHAGOIDES PTERONYSSINUS." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1247665992.
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Rojas, Mélida del Pilar Anzola. "Estratégias para a produção contínua de hidrogênio em reator anaeróbio de leito fixo." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-01102014-104046/.
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O reator anaeróbio de leito fixo tem demonstrado viabilidade para produzir hidrogênio a partir de águas residuárias. No entanto, a liberação do biogás não tem sido contínua devido à diminuição constante da carga orgânica volumétrica específica (COVe) causada pelo acúmulo de biomassa no leito ao longo do tempo. A redução da COVe junto com o envelhecimento da biomassa tem sugerido o estabelecimento de microorganismos consumidores dos constituintes do biogás (H2/CO2) responsáveis por cessar a produção de hidrogênio. Neste trabalho, cinco estratégias foram propostas visando a produção de hidrogênio por longo prazo operacional e com estabilidade, mediante a fixação da COVe, as quais incluíram a alteração da estruturação do leito, inverter o escoamento, realizar descartes periódicos de biomassa e variar a carga orgânica volumétrica aplicada (COV) por meio da variação do tempo de detenção hidráulica (TDH) e da concentração do substrato. Os resultados demonstraram que a manutenção da COVe em um valor adequado permite a produção contínua de hidrogênio. A ordenação do leito, utilizando polietileno de baixa densidade e espuma, e o escoamento descendente favoreceram a diminuição do acúmulo de biomassa e junto com os descartes de biomassa foi possível manter a COVe em um valor estável próximo de 5 g sacarose g-1 SSV d-1. A produção volumétrica de hidrogênio (PVH) foi contínua com valor médio de 0,6 L H2 L-1 d-1 e rendimento (YH2) próximo a 0,5 mol H2 mol-1 sc. Por outro lado, o escoamento ascendente e os descartes de biomassa em reator de leito empacotado e ordenado atingiram uma PVH média de 2,2 ± 0,2 e 3,13 ± 0,07 L H2 L-1 d-1 quando a COVe foi mantida em 2,6 e 4,4 g sacarose g-1 SSV d-1, respectivamente. Por último a variação da COV permitiu manter a COVe entre 3,8 e 6,2 g sacarose g-1 SSV d-1, atingindo um YH2 médio de 2 mol H2 mol-1 sc e um incremento da PHV de 2,4 a 8,9 L H2 L-1 d-1 durante 60 dias consecutivos. Ainda que com resultados satisfatórios referentes à manutenção por longo período operacional e estabilidade na produção de hidrogênio, a supersaturação deste gás no meio líquido, devido a limitações de transferência de massa, foi a principal causa de perdas de hidrogênio neste tipo de reator.Fixed-bed, anaerobic reactor has been shown to be feasible for hydrogen production from wastewater. However, biogas release has not been continuous due to the continuous specific organic load (SOL) decrease, which in turn is caused by biomass accumulation in the bed, through the time. SOL reduction and biomass ageing have indicated the establishment of the microorganisms that consumes the biogas constituents (H2/CO2) as the main cause for ceasing hydrogen production. In this work, five strategies were proposed aiming at obtaining longterm, stable hydrogen production by using SOL maintenance, modifications of the bed structure, flow inversion, periodic biomass discards and diverse organic load rates (OLR), as a function of the hydraulic retention time (HRT) and of the substrate concentration. Results demonstrated that by maintaining the SOL at proper values, continuous hydrogen production can be accomplished. On one hand, structuring the bed by using low-density polyethylene and foam, together with a down-flow and biomass discards were shown to diminish biomass accumulation, which led to keep a stable SOL value close to 5 g sucrose g-1 VSS d-1. Volumetric hydrogen production (VHP) was continuous with an average value of 0.6 L H2 L-1 d-1 and a yield (YH2) close to 0.5 mol H2 mol-1 sc. On the other hand, up-flow with biomass discharges, when implemented structured-bed and packed-bed reactors reached average VHP values of 2.2 ± 0.2 and 3.13 ± 0.07 L H2 L-1 d-1 as SOL was maintained between 2.6 and 4.4 g sucrose g-1 VSS d-1, respectively. Eventually, SOL was kept between 3.8 e 6.2 g sucrose g-1 VSS d-1 by varying the OLR, thus reaching an average YH2 value of 2 mol H2 mol-1 sc and a VHP increase from 2.4 to 8.9 L H2 L-1 d-1, along sixty consecutive days. As a consequence of mass-transfer limitations, oversaturation of hydrogen at the liquid medium was found as the main factor that causes hydrogen losses concerning fixed-bed reactors, even though the proposed strategies did indeed demonstrate long-term and stable hydrogen production.
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Diallo, Oumou. "Effect of Poultry Litter Biochar on Saccharomyces cerevisiae Growth and Ethanol Production from Steam-Exploded Poplar and Corn Stover." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/3901.
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The use of ethanol produced from lignocellulosic biomass for transportation fuel offers solutions in reducing environmental emission and the use of non-renewable fuels. However, lignocellulosic ethanol production is still hampered by economic and technical obstacles. For instance, the inhibitory effect of toxic compounds produced during biomass pretreatment was reported to inhibit the fermenting microorganisms, hence there was a decrease in ethanol yield and productivity. Thus, there is a need to improve the bioconversion of lignocellulosic biomass to ethanol in order to promote its commercialization. The research reported here investigated the use of poultry litter biochar to improve the ethanol production from steam-exploded poplar and corn stover. The effect of poultry litter biochar was first studied on Saccharomyces cerevisiae ATCC 204508/S288C growth, and second on the enzyme hydrolysis and fermentation of two steam-exploded biomasses: (poplar and corn stover). The third part of the study investigated optimal process parameters (biochar loading, biomass loading, and enzyme loading) on the reducing sugars production, and ethanol yield from steam-exploded corn stover. In this study, it has been shown that poultry litter biochar improved the S. cerevisiae growth and ethanol productivity; therefore poultry litter biochar could potentially be used to improve the ethanol production from steam-exploded lignocellulosic biomass.
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Hasna, Mahbuba Kaniz. "Corky root disease management in organic tomato production : composts, fungivorous nematodes and grower participation /." Uppsala : Dept. of Crop Production Ecology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/2007114.pdf.
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Meads, Michael Vearl. "Effects of Short Shoot Number and Presence of an Apical Meristem on Rhizome Elongation, New Short Shoot Production, and New Rhizome Meristem Production of Thalassia Testudinum Banks and Solander Ex König Planting Units in Tampa Bay." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4157.
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Thalassia testudinum Banks and Solander ex König is the dominant seagrass in the Gulf of Mexico, Caribbean and the West Coast of Florida, yet little rhizome elongation, new short shoot production, or new rhizome meristem production data has been collected via direct measurement. A study of the rhizome growth of T. testudinum was completed in December 2004 in southern Tampa Bay that determined growth after 26.5 months. Two PVC planting frames each containing four rhizomes with 2 short shoots, two rhizomes with 4 short shoots, and two rhizomes with 8 short shoots were planted next to existing T. testudinum beds at 5 sites (n = 10 planting frames). The rhizome apical meristem was removed from half of each set of short shoot units on each planting frame. Plants initially lacking a rhizome meristem produced more new long shoot meristems than those planted with an intact meristem, and larger planting units produced more new rhizome meristems than smaller ones, P = 0.001 and P < 0.001, respectively.
The total number of rhizome meristems per planting unit (new meristems + initial meristem) was greater in plantings initially lacking a long shoot meristem in the 2, 4 and 8 short shoot size classes. Only the two short shoot plants benefited from an intact rhizome meristem at planting time, elongating 66.4 cm versus 60.4 cm for plants initially lacking a rhizome meristem at 26.5 months. In the 4 and 8 short shoot classes, plants that
lacked a rhizome meristem at planting outpaced those with a meristem, producing 192.1 and 277.9 for 4 and 8 short shoot plants compared to 120.9 cm and 177.7 cm for plants with a meristem during the same time period. The greatest growth rate increases were due to lateral branching on planting units that lacked a rhizome meristem in the two largest size classes (4 and 8 short shoots); the differences between plants with an intact rhizome meristem and those without with the size classes pooled did not prove to be statistically different, P = 0.112. Differences among the size classes were significant, however, P < 0.001. Analysis of new short shoots was analogous to the results for rhizome elongation, with the presence of an initial rhizome factor proving insignificant, P = 0.401, and the initial number of short shoots factor proving significant, P < 0.001.
The rhizome growth, new short shoot production, and new rhizome meristem production data determined by direct measurements in this study appear to be the first planting unit measurements for this species under natural conditions.
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Yella, Lakshmi. "The Influence of Temperature on Population Growth and Allergen Production in Cultured House Dust Mites – Dermatophagoides pteronyssinus and Dermatophagoides farinae." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1260772254.
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Rouch, Matthew. ""Mining" for a Reference Condition in Southern West Virginia Streams." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3619.
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Quarterly samples were used to estimate assemblage-level (all species combined) fish production within three minimally-impacted, southern West Virginia streams. The total annual fish production estimate was highest in Slaunch Fork (37.52 kg∙ha-1∙y-1), a tributary of the Tug Fork River, and lowest in Cabin Creek (10.59 kg∙ha-1∙y-1), a Guyandotte River tributary. Creek Chub Semotilus atromaculatus, Mottled Sculpin Cottus bairdii and Blacknose Dace Rhinicthys atratulus were the most abundant species among sites, accounting for >90% of all sampled individuals. Reference condition criteria were also selected and metrics calculated for each of the three stream sites using a variety of established metrics. According to established criteria, all three of our sites scored high enough to be listed as “reference” sites. Third, a comprehensive GIS analysis was conducted in order to determine land use patterns and predict where similar assemblages would be present using various climatological and physical characteristics of our stream sites. These analyses revealed rapid expansion of surface mining activities putting many stream systems at risk.
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Kemski, Megan Marie. "Fish meal replacement with soybean meal in yellow perch (Perca flavescens) diets: responses of nutritional programming on growth, transcriptome and isoflavone accumulation." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534465279444556.
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Bithell, S. L. "An evaluation of Solanum nigrum and S. physalifolium biology and management strategies to reduce nightshade fruit contamination of process pea crops." Lincoln University, 2004. http://hdl.handle.net/10182/1160.
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The contamination of process pea (Pisum sativum L.) crops by the immature fruit of black nightshade (Solanum nigrum L.) and hairy nightshade (S. physalifolium Rusby var. nitidibaccatum (Bitter.) Edmonds) causes income losses to pea farmers in Canterbury, New Zealand. This thesis investigates the questions of whether seed dormancy, germination requirements, plant growth, reproductive phenology, or fruit growth of either nightshade species reveal specific management practices that could reduce the contamination of process peas by the fruit of these two weeds. The seed dormancy status of these weeds indicated that both species are capable of germinating to high levels (> 90%) throughout the pea sowing season when tested at an optimum germination temperature of 20/30 °C (16/8 h). However, light was required at this temperature regime to obtain maximum germination of S. nigrum. The levels of germination in the dark at 20/30 °C and at 5/20 °C, and in light at 5/20 °C, and day to 50 % germination analyses indicated that this species cycled from nondormancy to conditional dormancy throughout the period of investigation (July to December 2002). For S. physalifolium, light was not a germination requirement, and dormancy inhibited germination at 5/20 °C early in the pea sowing season (July and August). However, by October, 100% of the population was non-dormant at this test temperature. Two field trials showed that dark cultivation did not reduce the germination of either species. Growth trials with S. nigrum and S. physalifolium indicated that S. physalifolium, in a non-competitive environment, accumulated dry matter at a faster rate than S. nigrum. However, when the two species were grown with peas there was no difference in dry matter accumulation. Investigation of the flowering phenology and fruit growth of both species showed that S. physalifolium flowered (509 °Cd, base temperature (Tb) 6 °C) approximately 120 °Cd prior to S. nigrum (633 °Cd). The fruit growth rate of S. nigrum (0.62 mm/d) was significantly faster than the growth rate of S. physalifolium (0.36 mm/d). Because of the earlier flowering of S. physalifolium it was estimated that for seedlings of both species emerging on the same date that S. physalifolium could produce a fruit with a maximum diameter of 3 mm ~ 60 °Cd before S. nigrum. Overlaps in flowering between peas and nightshade were examined in four pea cultivars, of varying time to maturity, sown on six dates. Solanum physalifolium had the potential to contaminate more pea crops than S. nigrum. In particular, late sown peas were more prone to nightshade contamination, especially late sowings using mid to long duration pea cultivars (777-839 °Cd, Tb 4.5 °C). This comparison was supported by factory data, which indicated that contamination of crops sown in October and November was more common than in crops sown in August and September. Also, cultivars sown in the later two months had an ~ 100 °Cd greater maturity value than cultivars sown in August and September. Nightshade flowering and pea maturity comparisons indicated that the use of the thermal time values for the flowering of S. nigrum and S. physalifolium can be used to calculate the necessary weed free period required from pea sowing in order to prevent the flowering of these species. The earlier flowering of S. physalifolium indicates that this species is more likely to contaminate pea crops than is S. nigrum. Therefore, extra attention may be required where this species is present in process pea crops. The prevention of the flowering of both species, by the maintenance of the appropriate weed free period following pea sowing or crop emergence, was identified as potentially, the most useful means of reducing nightshade contamination in peas.
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Young, Ada. "IL-1β Amplification of Nitric Oxide Production and Its Inhibitory Effects on Glucose Induced Early Growth Response-1 Expression in INS-1 Cells." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1463.
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The pathophysiology of cytokines released by infiltrating white blood cells upon pancreatic beta cells is not fully understood. Early growth response gene-1 (Egr-1) expression is specifically and transiently up regulated in pancreatic beta cells in response to glucose. We hypothesized that interleukin-1 beta (IL-1▀) induction of nitric oxide alters glucose induced Egr-1 transcription levels. Egr-1 levels were assessed via western blot, nitric oxide was measured with a Griess Reagent kit and insulin levels via ELISA. Glucose induced both insulin and Egr-1 production in INS-1 cells. IL-1▀ dose dependently increased nitric oxide production over time and significantly attenuated glucose induced Egr-1 expression. Sodium nitroprusside dose dependently reduced glucose induced Egr-1 production. The data suggest a strong relationship between IL-1▀ induced nitric oxide production and the reduction of glucose stimulated Egr-1 production. The pathways altered by this cytokine could provide a better understanding of the pathophysiology leading to pancreatic beta cell death.
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Deblais, Loic. "Understanding of Salmonella-phytopathogen-environment-plant interactions and development of novel antimicrobial to reduce the Salmonella burden in fresh tomato production." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534437638478448.
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Ritterbusch, Cristina Weiser. "Propagação in vitro de portaenxertos de pessegueiro Flordaguard e GxN-9." Universidade Federal de Pelotas, 2013. http://repositorio.ufpel.edu.br/handle/ri/1997.
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Previous issue date: 2013-03-28The fruitful lump such as peaches, has shown annual growth of both production and consumption in Brazil and Rio Grande do Sul (RS) the leading national producer. However compared to other Brazilian states productivity in RS is considered low and one of the factors is the lack of genetic quality and health of propagation material. This is due in part to the means of acquiring rootstocks, which are derived from discarded lumps by canning industries, among other factors causing imbalance between plants in the orchard. Thus vegetative propagation from the micropropagation constitutes an alternative multiplication of rootstocks, obtaining a large number of plants in a short period of time compared with the traditional method used. Thus developing protocols for vegetative propagation may contribute to the process of producing seedlings prunaceas in southern Brazil. Therefore, the aim of this study was to optimize the in vitro multiplication rootstocks' Flordaguard 'and' GxN-9 'and in vitro rooting and acclimatization of shoots from the rooting medium with the rootstock' GxN-9 '. To this end, the work was divided into two chapters, one on the in vitro multiplication of rootstock "Flordaguard 'and the second concerning the multiplication, rooting and acclimatization of the rootstock' GxN-9 '. In the first chapter means were tested MS (1/2N) and Himedia, type and orientation of the explant and the concentration of BA. In the second chapter aimed to evaluate the effect of the concentration of cytokinins (BA and KIN) and the source and amount of carbohydrate in the multiplication phase, the influence of IBA concentration on rooting and acclimatization of plants. To rootstock 'Flordaguard' MS medium (1/2N) was superior to Himedia both to number of shoots per explant for growth as these. The growth of the sprout was highest in semi-solid medium with a liquid medium in comparison with semi-solid medium without liquid medium. However the type and orientation of the explant did not influence the number and length of shoots formed. For BA concentration, 3 mg L-1 induces greater number of shoots (4.02) but the greatest growth (1.85) of shoots occurred until the concentration of 0.5 mg L-1 BA. In the multiplication of 'GxN-9' explants cultured in medium containing 0.4 mg L-1 BA have the highest number of shoots the largest growth was achieved at concentrations of 0.2 mg L-1 BA + 0.2 mg L-1 KIN (0.72). Now, as to the source and concentration of carbohydrate, 30 g L-1 sucrose is sufficient for the greatest number of shoots. As regards à rooting phase in vitro and acclimatization induction, shoots cultivated in culture medium with 1.2 mg L-1 IBA, they had 100% rooting, well as of plants survivors in the phase of acclimatization.
As frutíferas de caroço, como o pessegueiro, vem apresentando expansão anual tanto da produção quanto do consumo no Brasil, sendo o Rio Grande do Sul (RS) o principal produtor nacional. No entanto, comparando com outros Estados brasileiros, a produtividade no RS é considerada baixa, sendo que um dos fatores é a falta de qualidade genética e sanitária do material propagativo. Isso deve-se em parte a forma de obtenção dos portaenxertos, os quais são oriundos de caroços descartados pelas indústrias de conserva, gerando entre outros fatores desuniformidade entre plantas no pomar. Sendo assim a propagação vegetativa a partir da micropropagação constitui-se em uma alternativa de multiplicação dos portaenxertos, obtendo uma grande quantidade de plantas num período curto de tempo em comparação com o método tradicional utilizado. Assim, desenvolver protocolos de propagação vegetativa poderá contribuir no processo de produção de mudas de prunaceas na região Sul do Brasil. O objetivo do presente trabalho foi otimizar a propagação in vitro dos portaenxertos Flordaguard e GxN-9 . Para tal, o trabalho foi dividido em dois capítulos, um sobre a multiplicação in vitro do portaenxerto Flordaguard e o segundo referente a multiplicação, enraizamento in vitro e aclimatização do portaenxerto GxN-9 . No primeiro capítulo foram testados os meios MS (1/2N) e Himedia, o tipo e a orientação do explante, bem como a concentração de BAP (Benzilaminopurina). No segundo capítulo, objetivou-se avaliar o efeito da concentração das citocininas (BAP e CIN), a fonte e a concentração de carboidrato na fase de multiplicação, e a influência da concentração de AIB no enraizamento e na aclimatização das plantas. Para o portaenxerto Flordaguard , o meio MS (1/2N) foi superior ao Himedia tanto para o número de brotações por explante quanto para o crescimento destas. O crescimento das brotações foi maior em meio semi-sólido com meio líquido em comparação ao meio semi-sólido sem meio líquido. Entretanto, o tipo e a orientação do explante não influenciou o número e o comprimento das brotações formadas. Considerando a concentração de BAP, 3 mg L-1 induz maior número de brotações (4,02), porém o maior crescimento (1,85) das brotações ocorreu até a concentração de 0,5 mg L-1 de BAP. Na multiplicação de GxN-9 , explantes cultivados em meio contendo 0,4 mg L-1 de BAP apresentam o maior número de brotações (2,88), porém o maior crescimento foi obtido nas concentrações de 0,2 mg L-1 de BAP+ 0,2 mg L-1 de CIN (0,72). Já, com relação a fonte e a concentração de carboidrato, 30 g L-1 de sacarose é suficiente para a multiplicação deste portaenxerto. No que diz respeito à fase de enraizamento in vitro e de aclimatização, brotações cultivadas em meio de cultura com 1,2 mg L-1 de AIB, tiveram 100% enraizamento, bem como de plantas sobreviventes na fase de aclimatização.
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Silva, Roberta Mafra Freitas da. "Reguladores do metabolismo bacteriano em reservatórios tropicais." Universidade Federal de São Carlos, 2017. https://repositorio.ufscar.br/handle/ufscar/9041.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Reservoirs located in tropical regions are main carbon (C) sources to the atmosphere, and bacterial metabolism is a key process that regulates those emissions. However, studies on the environmental drivers of bacterial metabolism in tropical reservoirs are scarce. By measuring metabolic rates and the limnological parameters in four cascading reservoirs that form a trophic state gradient, we determined the environmental drivers of bacterial metabolism in a tropical region, and compared them with those found in the literature (mainly from temperate regions). Our multiple regression models selected variables related to the trophic state as the main drivers of bacterial production (BP) and bacterial growth efficiency (BGE). On the other hand, bacterial respiration (BR), and consequently bacterial carbon demand (BCD), were weakly and negatively correlated to dissolved organic carbon (DOC), contrasting with the literature data. BR was always high, especially in less productive reservoirs where planktonic communities were limited by phosphorus. Nutrient limitation, high temperatures and high incident light intensity increased the environmental hostility, and cells must invest more energy in maintenance mechanisms, which directs the metabolism towards BR. This was observed in the reservoirs studied, especially in the more oligotrophic environments (Nova Avanhandava and Três Irmãos) where BR was higher and ECB lower. Our results indicate that the regulatory mechanisms of bacterial metabolism may vary according to latitude.
Reservatórios de regiões tropicais são fontes de carbono (C) para a atmosfera e o metabolismo bacteriano é um processo fundamental na regulação dessas emissões. No entanto, estudos que elucidem os fatores ambientais que determinam o metabolismo bacteriano em reservatórios tropicais são ainda escassos. Neste estudo foram medidas taxas metabólicas e parâmetros limnológicos em quatro reservatórios em cascata que formam um gradiente de estado trófico, com o intuito de determinar os reguladores do metabolismo bacteriano em uma região tropical e compará-los com dados obtidos a partir da literatura disponível (principalmente de regiões temperadas). Nossos modelos de regressão múltipla selecionaram variáveis relacionadas ao estado trófico como os principais reguladores da produção bacteriana (PB) e da eficiência de crescimento bacteriano (ECB). Foi encontrada uma relação fraca e negativa entre a respiração bacteriana (RB) e o carbono orgânico dissolvido (COD), diferente dos dados da literatura. As taxas de RB foram sempre elevadas, especialmente em reservatórios menos produtivos, nos quais as comunidades planctônicas estavam limitadas por fósforo. A escassez de nutrientes, as elevadas temperaturas e a alta intensidade de luz incidente aumentam o grau de hostilidade, e as células devem investir mais energia em mecanismos de reparação, o que direciona o metabolismo para a RB. Isso foi observado nos reservatórios estudados, especialmente, nos ambientes mais oligotróficos (Nova Avanhandava e Três Irmãos) nos quais a RB foi mais elevada e a ECB mais baixa. Nossos resultados indicam que os mecanismos reguladores do metabolismo bacteriano podem variar de acordo com a latitude.
FAPESP: 14/14139-3
FAPESP: 11/50054-4
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Hodge, Brian Allen. "Occurrence, Diversity, and Impact of Viruses in Ohio." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1606307407425512.
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Gudex, B. W. "Sireline variation in neonatal lamb cold tolerance." Lincoln University, 2001. http://hdl.handle.net/10182/1055.
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The cost of lamb mortality caused by cold exposure has been estimated at approximately 40 million dollars per year. This value is probably conservative as it does not include the cost due to the reduction in productivity in hypothermic lambs that manage to survive or the cost of reduced selection potential incurred by fewer lambs surviving until selection. The objectives of this research was to investigate whether sire-line variation exists in neonatal lamb cold tolerance and whether polymorphism in the β₃ adrenergic receptor gene can be used as a genetic marker for lamb cold tolerance and lean muscle growth. The influence of the climate, birthweight, age of dam at lambing, gender and birth rank on neonatal lamb cold tolerance was also analysed. Neonatal lamb mortality due to cold exposure was analysed in four field trials that used neonatal lamb morality from cold exposure as a predictor of neonatal lamb cold tolerance. Sire-line variation in neonatal lamb morality was observed in all trials, though it appeared that this effect was largely mediated through sire-line variation in lamb birth weight. Variation in lamb birth weight between birth rank classed was also found to be responsible for the influence of birth rank on neonatal lamb mortality due to cold exposure. The age of dam at lambing and the lamb gender was not observed to influence neonatal lamb mortality due to cold exposure. The sires from the cold tolerance study and the progeny of the lean muscle growth study were genotyped for the β₃ adrenergic receptor locus. Other studies have found evidence that a major gene exists in the catecholamine stimulation of brown adipose thermogenesis and evidence that the β₃-AR gene is a likely candidate. However, this hypothesis and the hypothesis that polymorphism in the β₃-AR gene is also linked to lean muscle growth in lambs was not confirmed in this study. So while it appears that the results were confounded by experimental design, there is evidence that influence of polymorphism in the ovine β₃ AR gene on neonatal lamb mortality and/or lean muscle growth is not sufficient to be considered a major gene effect. The implications of this experiment on the sheep industry and sheep farmers in general are huge. While completely eliminating lamb deaths due to inadequate cold tolerance is impossible, this study shows that large gains in lamb survival could be possible through selective breeding.
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Mason, Susan Leigh. "Metabolism of triacylglycerol-rich lipoproteins in sheep." Lincoln University, 1991. http://hdl.handle.net/10182/1756.
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This thesis describes two approaches for studying of lipoprotein metabolism in sheep. The first approach involves the assay of lipoprotein lipase (LPL) activity to determine the role of lipoprotein-triacylglycerol fatty acids in fat deposition in sheep. This enzyme is the rate limiting enzyme in the hydrolysis of fatty acids from lipoprotein-triacylglycerol. The second approach was to characterize and quantify in vivo lipoprotein metabolism using iodinated very low density lipoprotein (¹²⁵I-VLDL) and low density lipoprotein (¹³¹I-LDL). Cross-bred lambs were divided into two treatment groups and either weaned early at 5 weeks of age or remained suckling. Lambs were slaughtered at 12 or 23 weeks at which time the body composition and adipose tissue LPL activity were determined. The differences in rearing led to differences in body composition. The suckled lambs were larger and fatter than weaned lambs. The increased fatness in the suckled lambs was associated with increased LPL activity (U/mg protein) in subcutaneous adipose tissue and was reflected in higher LPL activity in post-heparin plasma (PHP) taken 2 days prior to slaughter. The role of insulin in the regulation of LPL activity was investigated by either infusing a subset of the weaned and suckled lambs with insulin for 7 or 18 weeks or using the euglycemic clamp technique to study the effect of short insulin infusions. The long term infusion of insulin had no significant effect on PHP LPL or on adipose tissue LPL (U/g tissue). However, after infusing insulin for 6h at 6.3 mU.kg⁻·⁷⁵.h⁻¹ during the euglycemic clamps, a two fold increase in LPL activity in biopsied subcutaneous adipose tissue was observed. In the second approach, in vivo lipoprotein metabolism was investigated in 4 lambs using apolipoprotein B as a marker. Following the simultaneous injection of ¹²⁵I VLDL and ¹³¹I VLDL, the specific activities of apoB in VLDL, IDL and LDL fractions were determined. ApoB specific activity curves demonstrated that VLDL is metabolised to IDL and subsequently to LDL. The turnover of VLDL-B (3.45mg.d⁻¹.kg⁻¹) and LDL-B (4.8mg.d⁻¹.kg⁻¹) was calculated by fitting the VLDL-¹²⁵I-B and LDL-¹³¹I-B specific activity data to a mono-exponential equation. The metabolism of lipoproteins, inferred from the study of apoB, was shown to be similar in sheep to that reported in other animals although the amount of lipoprotein synthesised was low. A model to describe the kinetics of apoB metabolism in sheep was developed using SAAM. The proposed model features a three pool delipidation chain for VLDL, and subsystems containing two pools for IDL and LDL. IDL may be catabolised to LDL or cleared directly from the plasma. The developed model can now be used to compare the metabolism of lipoproteins in different physiological states and to design new experiments to study lipoprotein metabolism further.
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Foury, Claude. "Quelques aspects du developpement de l'artichaut (cynara scolymus l. ) issu de semences : analyse plus particuliere de la floraison en conditions naturelles." Paris 6, 1987. http://www.theses.fr/1987PA066169.
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Etude faite pour 3 categories de contraintes : application en selection, absence d'enceinte climatisee, encombrement de la plante. Approche principale par l'echelonnement des semis. Etude des exigences en froid. Effets des traitements au ga::(3). Definition de regles de culture a partir de plants de semis. Etablissement de processus experimentaux de culture sequentielle en conteneur
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Moncousin, Charles. "Évolution de l'AIA, des composés phénoliques, de l'activité spécifique des péroxydases et de la production d'éthylène, au cours de la rhizogénèse, sur des microboutures de vigne (V. Riparia Michx. X V. Rupestris Scheele)." Nancy 1, 1987. http://www.theses.fr/1987NAN10216.
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L'étude de la thizogénèse adventive d'un clone de vigne, cultivé in vitro est menée conjointement par histocytologie et par le suivi de l'évolution temporelle de divers marqueurs métaboliques. Les phénomènes sont étudiés sur des boutures monomodales pourvues ou non de feuilles et dans le segment de tige placé au-dessus ou en-dessous du noeud. . .
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BERTHALON, ETIENNE. "Regulation de la voie de biosynthese de l'ethylene dans les cellules de tabac en culture sous l'effet d'eliciteurs fongiques." Toulouse 3, 1986. http://www.theses.fr/1986TOU30236.
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Sous l'effet de glycopeptides extraits de parois du mycelium de (phytophtora parantica nicotianae) et appeles eliciteurs, les cellules de tabac en culture synthetisent de grandes quantites d'ethylene. L'etude de l'hormone aux differentes etapes de sa voie de biosynthese montre une stimulation rapide et transitoire de l'activite acc-synthase, vraisemblablement par synthese de novo de l'enzyme, entrainant l'augmentation du taux intracellulaire d'acc sans pour autant modifier celui du n-malonyl-acc. (. . . )
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Haddad, Georges. "Aspects physiologiques de la culture du peuplier en taillis à courte rotation ; Fertilisation des sols par boues résiduaires." Grenoble 1, 1988. http://www.theses.fr/1988GRE10104.
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Etude de la periode favorable au recepage, effets du recepagez sur la croissance et sur la productivite. Etudes en laboratoire sur la culture en presence de mercure en milieu hydroponique et sur les potentialites de retention du sol. Effets sur la croissance et sur la composition chimique de l'application de boues residuaires
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Louerguioui, Ali. "Techniques de multiplication par clonage "in vitro" du genre eucalyptus." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37615472r.
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Couderchet, Michel. "Essai de quantification de la réponse à l'application de différents stress à partir d'une étude sur la chronosensibilité au froid chez le soja (glycine max [L. ] Merr. )." Besançon, 1988. http://www.theses.fr/1988BESA2025.
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Des plants sont exposes a une temperature de -10**(o)c pendant 4 minutes, a differents moments du nyethemere. La resistance au froid est maximale en find e photophase. On etudie les variations des teneurs en eau, en potassium et en chlorophylle, cette derniere methode pouvant etre utilisee pour quantifier la reponse a d'autres stress (ablations, herbicides) de facon non destructive. L'effet de substances de croissance sur la senescence des cotyledons semble impliquer une relation source puits a l'origine du mecanisme sous-jacent