Global ETD Search

11	Coxibs and traditional NSAIDs : systematic overviews of the randomised evidence for the effects of traditional non-steroidal anti-inflammatory drugs and selective inhibitors of cyclo-oxygenase-2 on vascular and upper gastrointestinal outcomes Bhala, Neeraj January 2013 (has links) No description available.
12	The immunotoxic effects of aldicarb Dean, Timothy Neal 14 March 2009 (has links) In the current studies the effects of administration of 0.1 to 1000 ppb of aldicarb, a carbamate pesticide, on the immune system of C3H mice were investigated. It was observed that aldicarb caused significant immunomodulation of macrophage functions analyzed in a variety of different systems. Initially, it was found that aldicarb decreased the stimulatory functions of the macrophages as studied by decreased capacity to stimulate normal autoreactive TF cells in the SMLR. This decreased stimulatory activity of the macrophages was found not to be due decrease in the expression of class II MHC-antigens (la molecules) nor was it due to the generation of any suppressor macrophages acting to down-regulate the immune response. Further investigations revealed that the decreased stimulatory activity of the macrophages correlated with decreased IL-1 production/signal to the T cells by the macrophages. It was also evident that aldicarb did not affect the T cell functions directly. Thus, T cells from aldicarb-treated mice when studied in the SMLR and AlloMLR or when stimulated with ConA or anti-CD3 mAbs, in the presence of normal macrophages, demonstrated normal responses. In contrast, normal T cells exhibited decreased responsiveness in the presence of aldicarb-treated macrophages. The fact that aldicarb did not affect the T cell functions directly was also evident by the fact that aidicarb-treated T cells could respond normally to stimulation with PMA + Ca²⁺ ionophore, a response which is independent of accessory cells. The aldicarb-treated macrophages also exhibited decreased capacity to process and present the antigen, conalbumin, to the T helper cell clone D10.G4. When the mechanism of aldicarb induced defect was investigated, it was observed that aldicarb-treated macrophages produced decreased amounts of IL-1 which was also confirmed by complete reconstitution of the response following addition of exogenous IL-1. With this in mind, macrophage functions in a number of other systems were examined and demonstrated that aldicarb-treatment also suppressed the macrophage-mediated cytotoxicity of tumor cells, but failed to inhibit the NK cell-mediated cytotoxicity of tumor cells. Together, these studies suggest that aldicarb selectively affects the macrophage but not NK or T ceil functions directly. However, since macrophages play an important role as accessory cells in T cell-mediated responses, it is likely that aldicarb indirectly will also affect the T cell responses. / Master of Science LD5655.V855 1990.D426 Immune system -- Effect of chemicals on Immunotoxicology -- Research Mice -- Effect of pesticides on Pesticides -- Toxicology
13	Changes in integrated cardiovascular physiology during inotropic stimulation in the early postnatal period Penny, Daniel James January 2004 (has links) Abstract not available Cardiovascular system -- Physiology Cardiotonic agents Adrenergic beta agonists Dobutamine -- Physiological effect Dopamine -- Physiological effect Lambs -- Physiology
14	Estimation of the Impact of Single Airport and Multi-Airport System Delay on the National Airspace System using Multivariate Simultaneous Models Nayak, Nagesh 01 January 2012 (has links) Airline delays lead to a tremendous loss of time and resources and cost billions of dollars every year in the United States (U.S.). At certain times, individual airports become bottlenecks within the National Airspace System (NAS). To explore solutions for reducing the delay, it is essential to understand factors causing flight delay and its impact on airports in the NAS. Major causal factors of flight delay at airports include over-scheduling, en-route convective weather, reduced ceiling and visibility around airports, and upstream delay propagation. Delay at one airport can be passed on to other airports in the NAS, in another word, operational improvement at one airport will have network effect and benefit to other airports as well. Moreover delay at different airports in a region might agglomerate to cause delay at different regions in the NAS. Hence, to optimally allocate NAS resources, e.g. capital investment for airport capacity expansion, the impact of single airport delay to the NAS and vice versa need to be investigated and quantified. For air transportation planning and policy purposes, this study concentrates on providing answers from a macroscopic point of view without being distracted by volatile operational details. In the first part, we estimate the interaction between flight delay at one single airport and delay at the rest of the NAS (RNAS) using case study for LaGuardia (LGA) and Chicago O'Hare (ORD) airports. In the second part, this research applies multivariate simultaneous regression models to quantify airport delay spillover effects across 34 of the 35 Operational Evolution Plan (OEP) airports and the RNAS. Observing the interactions between these two models, they are regressed with an econometric technique; three stage least square (3SLS). Thus, the regression results help us to determine the delay interactions between different airports and the RNAS and compare these airports based on delay propagation characteristics. Another significant contribution of this research is that, the estimated coefficients can be used for determining the marginal effects of all the delay causal factors presented in the model. Also, regional airport system development has been a hot topic of research in the air transportation community in recent years. Many metropolitan regions are served with more than one airport making their operations synchronized and interdependent and are known as regional airport system. This paper studies nine different prospective regions with multi-airport systems in the U.S. and identifies various key factors affecting the delay in these regions. Econometrics models and three stage least square (3SLS) estimation method are used to explore interdependency of delay at the multi-airport system and the RNAS. Along with it, different factors affecting delay at the system and the RNAS is being identified from the research. The outcomes from this research will help aviation planners understand the spillover effects of delays from multi-airport systems and provide decision support for future NAS improvement. 3SLS Delay Propagation Econometrics Macroscopic Tool System Effect American Studies Arts and Humanities Civil Engineering Urban Studies and Planning
15	Expression of genes encoding bacteriocin ST4SA as well as stress proteins by Enterococcus mundtii ST4SA exposed to gastro-intestinal conditions, as recorded by real-time polymerase chain reaction (PCR) Granger, Monique 03 1900 (has links) Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The tolerance of Enterococcus mundtii ST4SA to stressful gastro-intestinal conditions in humans and animals is vital to its success as a probiotic. The need for new effective probiotics with stronger inhibitory (bacteriocin) activity has arisen due to the increasing number of antibiotic resistant pathogens. Enterococci are used in the fermentation of sausages and olives, cheese making and as probiotics. Their role as opportunistic pathogens in humans makes them a controversial probiotic (Moreno et al., 2005). Enterococci occur naturally in the gastro-intestinal tract which renders them intrinsic acid and bile resistance characteristics. E. mundtii ST4SA produces a 3950 Da broad-spectrum antibacterial peptide active against Gram-positive and Gram-negative bacteria, and viruses. The bacteria include Enterococcus faecalis, Streptococcus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae and Staphylococcus aureus. E. mundtii ST4SA inactivates the herpes simplex viruses HSV-1 (strain F) and HSV-2 (strain G), a measles virus (strain MV/BRAZIL/001/91, an attenuated strain of MV), and a polio virus (PV3, strain Sabin). This study focuses on the genetic stability of E. mundtii ST4SA genes when exposed to stress factors in the human and animal gastrointestinal tract. Based on results obtained by real-time PCR, the expression of genes encoding bacST4SA, RecA, GroES and 23S rRNA by E. mundtii ST4SA were not affected when the cells were exposed to acid, bile and pancreatic juice. This suggests that these genes of E. mundtii ST4SA will remain stable in the intestine. This could indicate that other genes of E. mundtii ST4SA could remain stable in the host. Further studies on the stability of genes encoding antibiotic resistance and virulence factors should be conducted to determine their stability and expression in the host in stress conditions. Concluded from this study, E. mundtii ST4SA is an excellent probiotic strain. / AFRIKAANSE OPSOMMING: Enterococcus mundtii ST4SA se weerstandsvermoë teen stresvolle gastrointestinale kondisies is essensieel vir die sukses van hierdie organisme as ‘n probiotikum. Die aanvraag vir nuwe, meer effektiewe probiotika met sterker inhibitoriese (bakteriosien) aktiwiteit is as gevolg van die toename in antibiotikum weerstandbiedende patogene. Enterococci word algemeen gebruik as probiotika, sowel as in die fermentasie van worse, olywe en kaas. Hulle rol as oppertunistiese patogene in mense veroorsaak kontroversie as gevolg van hul toenemende gebruik as probiotika. Enterococci is deel van die natuurlike mikroflora in die gastrointestinale weg van mense en diere. Dit verleen aan hierdie spesies ‘n natuurlike weerstandsvermoë teen maagsure, galsoute en pankreatiese afskeidings. E. mundtii ST4SA produseer ‘n 3950 Da wye spektrum anti-bakteriese peptied, aktief teen Gram positiewe en Gram negatiewe bakterieë sowel as virusse. Hierdie bakterieë sluit Enterococcus faecalis, Streptococcus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae en Staphylococcus aureus in. E. mundtii ST4SA inaktiveer die herpes simpleks virus HSV-1 en HSV-2, ‘n masels virus (MV/BRAZIL/001/91), en ‘n polio virus (PV3, stam Sabin). Hierdie studie fokus op die genetiese stabiliteit van E. mundtii ST4SA gene, wanneer hulle blootgestel word aan stress faktore in die mens en dier gastrointestinale weg. “Intydse” PKR data gebasseer op die uitdrukking van die bacST4SA, RecA, GroES en 23S rRNA gene in stresvolle kondisies dui aan dat E. mundtii ST4SA nie geaffekteer word wanneer die sel blootgestel word aan suur, gal en pankreatiese vloeistowwe nie. Hierdie resultate dui aan dat hierdie gene van E. mundtii ST4SA stabiel sal bly in die intestinale weg van die mens en dier. Dit kan aandui dat ander gene van E. mundtii ST4SA soos die wat kodeer vir virulensie faktore en antibiotikum se weerstandsvermoë stabiel mag bly in die gasheer. Verdere studies wat fokus op die stabiliteit van gene wat kodeer vir antibiotikum weerstandbiedendheid en virulensie faktore moet uitgevoer word om hulle stabiliteit en uitdrukking in die gasheer te bepaal. Bevindings van hierdie studie dui aan dat E. mundtii ST4SA goeie potensiaal het as ‘n probiotikum. Gene expression Bacteriocins Heat shock proteins Enterococcus -- Genetics Gastrointestinal system -- Microbiology Polymerase chain reaction Probiotics Lactic acid bacteria Theses -- Microbiology Dissertations -- Microbiology
16	Scaling methods of leakage correction in GRACE mass change estimates revisited for the complex hydro-climatic setting of the Indus Basin Tripathi, Vasaw, Groh, Andreas, Horwath, Martin, Ramsankaran, Raaj 18 April 2024 (has links) Total water storage change (TWSC) reflects the balance of all water fluxes in a hydrological system. The Gravity Recovery and Climate Experiment/Follow-On (GRACE/GRACE-FO) monthly gravity field models, distributed as spherical harmonic (SH) coefficients, are the only means of observing this state variable. The well-known correlated noise in these observations requires filtering, which scatters the actual mass changes from their true locations. This effect is known as leakage. This study explores the traditional basin and grid scaling approaches, and develops a novel frequency-dependent scaling for leakage correction of GRACE TWSC in a unique, basin-specific assessment for the Indus Basin. We harness the characteristics of significant heterogeneity in the Indus Basin due to climate and human-induced changes to study the physical nature of these scaling schemes. The most recent WaterGAP (Water Global Assessment and Prognosis) hydrology model (WGHM v2.2d) with its two variants, standard (without glacier mass changes) and Integrated (with glacier mass changes), is used to derive scaling factors. For the first time, we explicitly show the effect of inclusion or exclusion of glacier mass changes in the model on the gridded scaling factors. The inferences were validated in a detailed simulation environment designed using WGHM fields corrupted with GRACE-like errors using full monthly error covariance matrices. We find that frequency-dependent scaling outperforms both basin and grid scaling for the Indus Basin, where mass changes of different frequencies are localized. Grid scaling can resolve trends from glacier mass loss and groundwater loss but fails to recover the small seasonal signals in trunk Indus. Frequency-dependent scaling can provide a robust estimate of the seasonal cycle of TWSC for practical applications such as regional-scale water availability assessments. Apart from these novel developments and insights into the traditional scaling approach, our study encourages the regional scale users to conduct specific assessments for their basin of interest. info:eu-repo/classification/ddc/550 ddc:550
17	Utvecklingen av marknadsvärdet för svenska frekvenshållningsreserver 2024–2030 : En prognos för utvecklingen av marknadsvärdet för frekvenshållningsreserverna FCR-N, FCR-D upp och FCR-D ned på den svenska balansmarknaden mellan 2024 och 2030 / The Development of the Market Value of Swedish Frequency Containment Reserves 2024–2030 : A forecast for the development of the market value for the frequency containment reserves FCR-N, FCR-D up and FCR-D down in the Swedish balancing market between 2024 and 2030 Ludvig, Aldén, Gustav, Espefält, Gabriel, Gabro January 2024 (has links) I takt med en ökad andel variabel förnybar elproduktion i Sveriges energimix blir elnätets flexibilitet allt viktigare för att upprätthålla en stabil elförsörjning. Detta arbete undersöker framtida prognoser för priser och volymer på de svenska frekvenshållningsreserverna FCR-N, FCR-D upp och FCR-D ned fram till år 2030. Prognoser för sådan utveckling är viktiga för elmarknadens aktörer och deras beslut att investera i flexibilitetsresurser. SARIMAX-modeller utvecklades baserade på historisk data och antaganden om framtida utvecklingar, vilka i sin tur grundades på en intervju med en branschexpert samt aktuella kartläggningar och rapporter. Resultaten visar på en markant nedåtgående pristrend. För FCR-N prognostiseras priserna sjunka med 367 % från 2024 till 2030, från 29 euro/MW till 5 euro/MW. FCR-D upp förväntas följa en liknande trend med ett prisfall på 325 %, från 20 euro/MW år 2024 till 4 euro/MW år 2030. Den kraftigaste prisnedgången prognostiseras för FCR-D ned, där priserna beräknas rasa med över 1900 % under samma period - från 61 euro/MW år 2024 till endast 3 euro/MW år 2030. Vad gäller volymer visar prognoserna på en relativt stabil utveckling kring upphandlingsplanerna, med en viss ökning för FCR-D ned på 44 % från 2024 till 2030. Den pågående etableringen av batterilager förutses ha stor påverkan genom att öka konkurrensen och pressa priserna nedåt. De låga prisnivåerna 2030 kan dock göra det utmanande att motivera investeringar enbart baserat på intäkter från FCR-marknader. Vidare diskuteras modellernas begränsningar samt behovet av framtida forskning kring batteriteknik, råvaruaspekter och avancerade simuleringsmodeller för att bättre förstå marknadsdynamiken. / As the share of variable renewable electricity production increases in Sweden's energy mix, the flexibility of the power grid becomes increasingly important to maintain a stable electricity supply. This study aims to forecast prices and volumes of the Swedish frequency containment reserves FCR-N, FCR-D up, and FCR-D down until 2030. Forecasts of such developments are important for electricity market participants and their decisions to invest in flexibility resources. SARIMAX models were developed based on historical data and assumptions about future developments, which in turn were based on an interview with an industry expert as well as current reports. The results indicate a significant downward price trend. For FCR-N, prices are forecasted to decrease by 367% from 2024 to 2030, dropping from 29 euros/MW to 5 euros/MW. FCR-D up is expected to follow a similar trend with a 325% price drop, from 20 euros/MW in 2024 to 4 euros/MW in 2030. The sharpest price decline is forecasted for FCR-D down, where prices are estimated to plummet by over 1900% during the same period - from 61 euros/MW in 2024 to only 3 euros/MW in 2030. Regarding volumes, the forecasts show a relatively stable development around the procurement plans, with a certain increase for FCR-D down by 44% from 2024 to 2030. The ongoing establishment of battery storage is expected to have a major impact by increasing competition and putting downward pressure on prices. However, the low price levels in 2030 may make it challenging to justify investments based solely on revenues from FCR markets. Furthermore, the limitations of the models are discussed, as well as the need for future research on battery technology, raw material aspects, and advanced simulation models to better understand market dynamics. FCR frequency containment reserves FCR-N FCR-D up FCR-D down upregulation downregulation variable renewable energy VRE power grid power system flexibility electricity supply stable forecast electricity market SARIMAX time series modeling data price volume market value energy storage battery storage battery park batteries competition time series flexibility resource flexibility service risk system effect future scenarios scenario balancing market volume development investment decisions scenario analysis uncertainty management sensitivity analysis competitive situation commodity prices technology development policy impact capacity expansion profitability calculations risk management FCR frekvenshållningsreserver FCR-N FCR-D upp FCR-D ned uppreglering nedreglering variabel förnybar energiproduktion VRE elnät kraftsystem flexibilitet elförsörjning stabil prognos elmarknad SARIMAX tidsseriemodellering data pris volym marknadsvärde energilagring batterilager batteripark batterier konkurrens tidsserie flexibilitetsresurs flexibilitetstjänst risk systemeffekt framtidsscenarier scenario balansmarknad volymutveckling investeringsbeslut scenarioanalys osäkerhetshantering känslighetsanalys konkurrenssituation råvarupriser teknologiutveckling policypåverkan kapacitetsutbyggnad lönsamhetsberäkningar riskhantering Energy Systems Energisystem

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