Dissertations / Theses on the topic 'Effect of chemicals on'
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Filby, Amy Louisa. "Molecular effect pathways of endocrine disrupting chemicals in fish." Thesis, University of Exeter, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439828.
Full textDelacruz, C. Ligia. "The effect of natural toxicants and other chemicals on the kidney." Thesis, University of Surrey, 1988. http://epubs.surrey.ac.uk/847359/.
Full textQuinn, Amie L., and University of Lethbridge Faculty of Arts and Science. "The impacts of agricultural chemicals and temperature on the physiological stress response in fish." Thesis, Lethbridge, Alta. : University of Lethbirdge, Faculty of Arts and Science, 2007, 2007. http://hdl.handle.net/10133/676.
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Li, Jing Adela, and 李晶. "Temperature-dependent toxic effects of selected chemicals on marine organisms." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/211051.
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Biological Sciences
Doctoral
Doctor of Philosophy
Casa, Maria V. "Accumulation of Emerging Chemicals in Southern Hemisphere Humpback Whales (Megaptera novaeangliae) and Species-specific Chemical Effect Assessment." Thesis, Griffith University, 2022. http://hdl.handle.net/10072/411890.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Coberly, Samantha W. "The effect of household chemicals on deciduous and permanent tooth class." Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/6807.
Full textThesis (M.A.)--Wichita State University, Fairmount College of Liberal Arts and Sciences, Dept. of Anthropology
Turan, Nahid. "The effect of plasticisers and related chemicals on sulphate supply enzymes." Thesis, University of Birmingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433746.
Full textHoward, Samuel Clarence. "The effect of three holding tank chemicals on anaerobic wastewater treatment." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45158.
Full textMaster of Science
Reed, Susan, of Western Sydney Hawkesbury University, and of Science Technology and Environment College. "Development of method to assess skin contact to chemicals." THESIS_CSTE_XXX_Reed_S.xml, 2001. http://handle.uws.edu.au:8081/1959.7/611.
Full textDoctor of Philosophy (PhD)
Montambault, François. "The use of Hoe-39866 as a potato-top desiccant /." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61703.
Full textWeyand, Eric Henry. "The metabolic fate of benzo [a] pyrene in vivo." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/77786.
Full textPh. D.
Tomic, Tjasa. "Functionalised cellulosic materials for hydrolysis free reactive dyeing and the fixation of effect chemicals." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498845.
Full textMeyer, Stephanie Kristen. "Effects of oestrogenic chemicals on the liver." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3654.
Full textOliveira, Rhaul. "Effects assessment of chemicals used in aquaculture." Doctoral thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/16297.
Full textAquaculture provides food and income for millions of families worldwide being an activity with a high growth rate and with a strong potential for further expansion. Both producers and consumers are interested in a sustainable model of aquaculture development covering social, economic and environmental aspects. Such model implies to cope with the environmental impacts generated by aquacultures. The main objective of this work was to evaluate the use of chemicals applied in aquaculture farms and their harmful effects to aquatic organisms. Since more than 80% of global production of aquatic organisms is concentrated in Southwest Asia, special attention was given to the aquaculture in this region, particularly Thailand. Three different types of aquaculture scenarios were studied: shrimp farms and tilapia farms in cages and in earth ponds. Surveys and monitoring campaigns were conducted in several farms and the fate, use and application patterns of chemicals were identified. In cage farms the results indicated overuse/misuse of antibiotics, in shrimp farms the major group of chemicals used were disinfectants whereas in earth pond farms 1,7α-methyltestosterone (MT) was the most used. The results from the monitoring campaigns showed that the excessive use of chemicals was correlated to contamination of the surrounding environment namely with the antibiotics oxytetracycline (OTC) and enrofloxacin (ENR) in the cage farms, and with MT in the earth pond farms. In the laboratory, ecotoxicity assays were performed with antibiotics, disinfectants and pesticides using organisms belonging to different trophic levels. The disinfectants benzalkonium chloride (BKC), chlorhexidine gluconate (ChD) and glutaraldehyde (GA) were tested. BKC and ChD demonstrated to be very toxic to primary and secondary consumers. Moreover, an approach based on the species sensitivity distributions (SSD) was used to estimate the hazardous concentrations for 5 and 50 % of the species after BKC and GA exposure highlighting the sensitivity of primary producers to BKC exposure (HC5 = 10.8 μg/l). In the case of GA, different trophic levels showed similar sensitivities and a general HC5 = 300 μg/l was obtained. Additionally, a probabilistic environmental risk assessment was performed indicating a PAF (potentially affected fraction) of species > 5% for adverse effects of BKC in effluents and surface water. Concerning pesticides, both trichlorfon (TCF) and ivermectin (IVM) were studied. TCF showed to be extremely toxic to daphnids (48h- LC50 = 0.29 μg/l) and affected the acetilcolinesterase activity in D. magna and D rerio. IVM showed to be acutely toxic to D. rerio life stages (96h-LC50 = 18.5 μg/l for juveniles) and affected their development and biomarkers. In chronic exposures, IVM led to changes in the behaviour and growth of D. rerio juveniles (21d-LOEC < 0.25 μg/l). The antibiotics amoxicillin and OTC were not acutely toxic to aquatic organisms but both induced oxidative stress related enzymes of adults and embryos of D. rerio. Globally, most of the tested chemicals showed to compromise at least a particular group of organisms or sub-lethal parameters, requiring further long term studies so that the environmental risk assessment of these compounds can be refined. Lethal and sub lethal effects obtained to non-target organisms suggest a potential biodiversity loss in the aquatic ecosystems which might, thus, compromise the services provided by the ecosystems in a near future. Since the aquaculture relies directly on these services (e.g. high water quality) to succeed, there is an urgent need of control/education measures both in the use of chemicals in aquaculture and monitoring/mitigation of adverse impacts in natural ecosystems.
A aquacultura fornece sustento para milhões de famílias, sendo uma actividade em crescimento e com um forte potencial de expansão em todo o mundo. Há um interesse por parte de produtores e consumidores em desenvolver modelos sustentáveis de aquacultura abrangendo aspectos sociais, económicos e ambientais. Tais modelos implicam lidar com os impactos ambientais gerados pela aquacultura. O principal objectivo deste trabalho foi estudar o uso de produtos químicos usados nas aquaculturas e avaliar os seus efeitos nocivos para organismos aquáticos. Uma vez que mais de 80% da produção mundial de organismos aquáticos está concentrada no sudoeste da Ásia, foi dada especial atenção à aquacultura nessa região, particularmente na Tailândia. Três diferentes cenários foram considerados: aquaculturas de camarão, aquaculturas de tilápias cultivadas em gaiolas e em tanques escavados no solo. Em cada tipo foram realizados inquéritos e campanhas de monitoramento em várias aquaculturas nas quais foram averiguados o uso, destino e forma de aplicação de químicos. Os resultados indicaram o uso excessivo/inapropriado de alguns compostos, nomeadamente de antibióticos (em aquaculturas em gaiolas), de desinfectantes (em aquaculturas de camarão) e de 1,7α-metiltestosterona (MT) (em aquacultura de tilápias em tanques escavados). Os resultados das campanhas de monitorização mostraram que o uso excessivo de produtos químicos resulta na contaminação do meio ambiente com antibióticos (oxitetraciclina (OTC) e enrofloxacina (ENR)) nas aquaculturas em gaiola, e com MT nas aquaculturas de tilápias em tanques escavados. No laboratório, foram realizados ensaios de ecotoxicidade com antibióticos, desinfectantes e pesticidas usando organismos modelo pertencentes a diferentes níveis tróficos. Foram testados os desinfectantes, cloreto de benzalcónio (BKC), gluconato de clorexidina, e glutaraldeído (GA) sendo que os dois primeiros demonstraram ser muito tóxico para consumidores primários e secundários. Para uma análise integrada foi utilizada uma abordagem baseada nas distribuições de sensibilidade das espécies (DSE) com a qual se estimaram as concentrações perigosas (CP) para 5% e 50% das espécies após e exposição ao BKC e GA. O grupo dos produtores primários foi o grupo mais sensível à exposição ao BKC com CP5% = 10,8 μg/l enquanto para GA não foram encontradas diferenças de sensibilidade entre os grupos tróficos e, assim sendo, um valor geral de CP5% = 300 μg/l foi obtido. Além disso, uma análise probabilística dos riscos ambientais indicou uma fracção de espécies potencialmente afectada (FAPE) pelo BKC > 5% em efluentes e águas superficiais. Os pesticidas estudados foram o trichlorfon (TCF) e a ivermectina (IVM). O TCF foi extremamente tóxico para dafnídeos (48h-LC50 = 0,29 μg/l) e afectou também a actividade de acetilcolinesterase em D. magna e D. rerio. A IVM foi tóxica para adultos, juvenis e embriões de D. rerio (96h- CL50 = 18,5 μg/l para os juvenis) afectando o seu desenvolvimento e actividade de biomarcadores. Em exposições crónicas, IVM causou alterações no comportamento e crescimento em D. rerio juvenis (21d-LOEC <0,25 μg/l). Os antibióticos amoxicilina e OTC apresentam baixa toxidade para os organismos aquáticos, mas ambos induziram enzimas relacionadas estresse oxidativo em adultos e embriões de D. rerio. Em geral, a maioria dos químicos testados apresentaram toxicidade para algum grupo de organismo da cadeia trófica ou tiveram efeito a nível de parâmetros sub-letais, sendo portanto recomendados estudos de exposição crónica para que se possa refinar a avaliação de risco ambiental destes compostos. Os efeitos letais e sub-letais observados nos organismos não-alvo sugerem que pode haver uma perda da biodiversidade nos ecossistemas aquáticos, e assim, comprometer os serviços prestados pelos ecossistemas num futuro próximo. Sendo o sucesso da aquacultura dependente directo destes serviços (por exemplo, água de alta qualidade), há uma necessidade urgente de medidas de controlo/educação, tanto no uso de produtos químicos na aquacultura e monitoramento/mitigação dos impactos negativos destes nos ecossistemas naturais.
Seggio, Joseph A. "Chronic Ethanol Modulated Photic and Non-photic Phase Responses in Syrian Hamster and C57BL/6J Inbred Mouse." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/SeggioJA2009.pdf.
Full textDwyer, Suzanne. "Effects of Neonatal Clomipramine Treatment on Photic and Non-Photic Circadian Phase Shifting in Rats." Fogler Library, University of Maine, 2000. http://www.library.umaine.edu/theses/pdf/DwyerSM2000.pdf.
Full textAmoako, Daniel Kwasi. "Cyclopiazonic acid changes the mode of excitation-contraction couplingin acetylcholine-stimulated bovine tracheal smooth muscle." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B3121387X.
Full textYeung, Chiu Wai. "Neurotoxicological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on cultured neurons." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/529.
Full textLi, Yuhong, and n/a. "Effect of alcohol exposure in early gestation on brain development." University of Otago. Department of Anatomy & Structural Biology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070502.100319.
Full textWorsham, Jessica Nicole. "5-HT3 Receptor Ligands and Their Effect on Psychomotor Stimulants." VCU Scholars Compass, 2008. http://scholarscompass.vcu.edu/etd/1054.
Full textManzan, Martins Camilla. "EFFECT OF ENDOCRINE DISRUPTORS ON HUMAN ENDOMETRIAL STROMAL CELLS AND THEIR INTERACTION WITH TROPHOBLAST." Doctoral thesis, Università di Siena, 2022. http://hdl.handle.net/11365/1183943.
Full textReed, Susan. "Development of method to assess skin contact to chemicals." Thesis, View thesis View thesis, 2001. http://handle.uws.edu.au:8081/1959.7/611.
Full textChan, Sai Yen Victor, and 陳世欽. "Effect of homocysteine on nitric oxide production in cardiomyocytes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31970321.
Full textHolcroft, Joanna (Joanna Mary Steward). "Effect of Anolyte on broiler performance." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/18708.
Full textENGLISH ABSTRACT: A farm in Zimbabwe (Farm A) obtains its water for tbe poultry operations from tbe Makavusi River that is heavily contaminated with bacteria and performance results are thereby reduced. Anolyte is a Russian invention that claims to have bactericidal effects that could be beneficial to broilers. The aim of this research is to investigate the effect of Anolyte on production profits of broilers given water of poor quality by carrying out a number of trials. Trials that were conducted are basic in vitro tests on Anolyte within the laboratory, water analysis on water supply to the broiler section (both chemical and bacteriological), and a detailed trial within an experimental trial site comparing broiler performance results with different chemical water treatments and different dilutions of Anolyte. Broiler chicks from different hatcheries (Hatchery A and Hatchery B) were also compared. Performance results were based on growtb rate, mortality, feed conversion ratios (FCR), performance efficiency factors (PEF) and profit margin comparisons. Results showed that in tbe laboratory, Anolyte had an antibacterial activity. In the broiler performance trial on Hatchery B broilers, the live weights at forty two days of age in broilers given 15% Anolyte differed from other treatments (P<0.05) other than 10% Anolyte (P > 0.05). However, the FCR and mortalities did not differ (P > 0.05) between treatments. In the trial on Hatchery A broilers to 42 days of age, growth rates in broilers given 15% Anolyte differed from tbe control, Chematron and 20% Anolyte (P < 0.05). However, the FCR and mortalities did not differ between (P>0.05) treatments. In comparing chicks from different hatcheries, Hatchery B broilers differed (P < 0.05) from Hatchery A broilers in live weights at 42 days on 10% Anolyte, 15% Anolyte and on Chematron treatments. However, tbe cumulative mortalities and FCR did not differ (P > 0.05) between the Hatchery B and Hatchery A on any treatment. When comparing profitability, tbe treatment that had the greatest margin in comparison to tbe control (untreated drinking water) was 15% Anolyte for both tbe Hatchery B and Hatchery A trials.
AFRIKAANSE OPSOMMING: 'n Plaas in Zimbabwe, (Plaas A) verkry water, vir hul pluimvee bedryf vannuit die Makavusi rivier. Die rivier is swaar besmet met bakterië en as gevolg daarvan verhoed dit dat hulle hul volle opbrengs potential bereik. Anolyte is 'n Russiese uitvindsel wat aanspraak maak daarop dat dit bakteriëdodende effekte besit wat tot die bevordering van slaghoenders kan lei. Die doel van die navorsing is om Anolyte op proef te stel aangaande produksie profyt op slaghoenders waaraan swak kwaliteit water verskaf is. Verskeie toetse is uitgevoer n1. 'n basiese 'in vitro' toets in samewerking met die laboratorium, water ontleding op water wat aan die slaghoender seksies verskaf is (beide chemikalies and bakterieologies) asook 'n intensiewe proefnemeing waarin die verskeie obrengs resultate, van chemikaliese behandelde water en verskillende verdunnings van Anolyte, met mekaar vergely is, in 'n experimetele navorsings eenheid. Slaghoender kuikens van twee verskillende broeihuise (n1. Broeihuis A en Broeihuis B) is ook met mekaar vergelyk. Die resultate is gabasseer op groei tempo, sterftes, voer omsettings verhouding, opbrengs geskikthied faktore asook vergelykings op wins. Laboratorium navorsing het bevestig dat Anolyte wel antibakteriese aktiviteit getoon het. Terwyl in die proefneming op Broeihuis B slaghoenders, het die lewende gewig van hoenders, op 42 dae van ouderdom, waaraan 15% Anolyte verskaf is, verskil van ander behandelings (P<0.05) met die uitsondering van 10% Annolyte (P>0.05). Alhoewel die voer omsetting verhoudings en sterftes nie in die verskillende behandelings verskil het nie. In die proefnemeing op Broeihuis A slaghoenders tot 42 dae van ouderdom, het die ontwikkeling van slaghoenders, waaraan 15% Anolyte verskaf is, verskil van die kontiole, Chematron en 20% Anolyte. Die voer omsettings verhoudings en sterftes het egter geen verskil getoon tussen die verskeie behandelings nie. Resultate van die vergelyking tussen die kuikens uit die twee verskillende broeihuise, het getoon dat die Broeihuis A en Broeihuis B lewensgewigte, op 42 dae van ouderdom, wel met mekaar verskil het met 10% Anolyte, 15% Anolyte sowel as die Chematron behandelings. Daar was egter geen verskil, (P>O.05) tussen die twee tipes aangaande elke tipe se saamgestelde sterftes en die voer omsettings verhoudings, in welke behandeling nie. Die vergelykings op wins het getoon dat die behandeling met die grootste brulo marge, die was van 15% Anolyte in vergelyking met die kontiole (onbehandelde drinkwater) vir beide die Broeihuis A en die Broeihuis B proefnemings.
Nongauza, Sinethemba Aubrey. "An investigation of the effect of co-solvents on the hydrothermal liquefaction of microalgae biomass." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/21667.
Full textWei, Juntong. "Mass spectrometry-based metabolomics to unveil the polybrominated diphenyl ether-47 induced alteration in breast carcinoma." HKBU Institutional Repository, 2019. https://repository.hkbu.edu.hk/etd_oa/661.
Full textLau, Wai Kit Jaeger. "Developmental expression of N-methyl-D-aspartate and gamma-aminobutyric acid receptors in the rat basal ganglia." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/535.
Full textLam, Wai Chi Rebecca. "Expression of metabotropic glutamate receptors in the rat striatum during postnatal development." HKBU Institutional Repository, 2003. http://repository.hkbu.edu.hk/etd_ra/528.
Full textKile, Joanna L. (Joanna Le). "The Reproductive Consequences of Carriers of Methylenebisacrylamide-Induced Balanced Reciprocal Translocations in Mus Musculus." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc500402/.
Full textGoats, Geoffrey Charles. "Assessment of the effects of toxic chemicals upon earthworms." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37706.
Full textMerritt, Rebecca L. "The effects of environmental chemicals on glioblastoma cell growth." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3475.
Full textTitle from document title page. Document formatted into pages; contains vii, 78 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 70-78).
Shubat, Pamela Jane. "Monocrotaline toxicity and pulmonary arteries." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184533.
Full textOmami, Elizabeth Nabwile, of Western Sydney Hawkesbury University, of Agriculture Horticulture and Social Ecology Faculty, and School of Horticulture. "Amaranthus retroflexus seed dormancy and germination responses to environmental factors and chemical stimulants." THESIS_FAHSE_HOR_Omami_E.xml, 1993. http://handle.uws.edu.au:8081/1959.7/66.
Full textMaster of Science (Hons)
Castillo-Ruiz, Priscila. "Plant activation of different chemicals by tobacco and brassica cell cultures, using the plant cellmicrobe coincubation assay." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39239.
Full textLough, Kerry Frances. "The Short and Long-term Effects of Herbicide Application in Maine Clearcuts on Ant Communities (Hymenoptera: Formicidae)." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/LoughKF2003.pdf.
Full textPoon, Ming-see Angela, and 潘明施. "Binding of 2[125I]iodomelatonin in the guinea pig spleen: evidence for a direct action of melatonin on themammalian immune system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31233855.
Full textAllison, Edwin. "Effects of seed adjuvants on germination and development of onions." Thesis, Cape Technikon, 2001. http://hdl.handle.net/20.500.11838/2000.
Full textOnion seeds (cultivar Caledon Globe), and soil into which the seedlings were planted, were treated with various adjuvants including fungicides, a seed disinfectant and a soil sterilant, as well as soil-applied growth stimulants to determine the effect of these on germination of seed, the growth of plants and the storage life of onions obtained. Three sets of germination trials were undertaken in petri dishes, and sets of seed was also sown in deep seed trays. A trial planting was made and the crop graded and stored. Seed was also sown in pots in soil obtained from a commercial undertaking where poor germination had been obtained. A portion of this soil was pasteurised and a portion inoculated with Fusarium spp. Growth of these seedlings was then followed by re-sowing in the same pots using seed of additional cultivars.
Miller, Lana L., and University of Lethbridge Faculty of Arts and Science. "The effects of selenium on the physiological stress response in fish." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2006, 2006. http://hdl.handle.net/10133/397.
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Mayles, Karen Marie 1957. "Chemical regulation of growth and fruit maturity of Vitis vinifera 'Flame Seedless' using hydrogen cyanamide." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276605.
Full textChidgey, Laura Louise. "An integrated approach to unravel the effect pathways of endocrine disrupting chemicals on the developing zebrafish, Danio rerio." Thesis, University of Exeter, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.496171.
Full textSandoval, Mojica Andres Felipe. "Antifeedant effect of commercial chemicals and plant extracts against Schistocerca americana (Orthoptera: Acrididae) and Diaprepes abbreviatus (Coleoptera: Curculionidae)." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024748.
Full textOliveira, Eva Lima de Castro. "Ecotoxicological bioassays to evaluate the effects of chemicals in soil." Master's thesis, Universidade de Aveiro, 2008. http://hdl.handle.net/10773/801.
Full textA utilização de compostos químicos e os consequentes efeitos em distintos compartimentos ambientais tem despertado muito interesse nos últimos anos.O aparecimento de Produtos de Higiene Pessoal no ambiente tem sido considerado como uma questão a ser colocada no domínio ambiental. A sua presença no ambiente ocorre devido á excessiva utilização por parte dosconsumidores e à sua incompleta remoção das estações de tratamento de águas residuais. Nessas estações os efluentes tratados e lamas sãonovamente reintroduzidos no ambiente e na maioria dos casosafectam os organismos residentes nas comunidades locais. Um outro tipo de compostos que também têm recebido atenção especial é os Hidrocarbonetos Policíclicos Aromáticos (HPAs), que desde a sua primeira aparição no solo, despertaramgrande curiosidade. Estes compostos são derivados da combustão incompletade compostos contendo carbono e hidrogénio e do processo diagénese. Com estetrabalho pretendemos avaliar a toxicidade do Triclosan num conjuntode organismos-teste terrestres, lumbricideos (Eisenia andrei), colêmbolos (Folsomia candida), enquitraideos (Enchytraeus albidus), incluindo dois tipos de plantas superiores (Triticum aestivum e Brassica rapa). Os parâmetros avaliados foram a germinação e crescimento das plantas e a sobrevivência/reprodução dos restantes organismos. Também foi realizado um ensaio de bioacumulação para avaliar o comportamento cinético de um HPA, o fenantreno em E. albidus. Para a determinação da concentração de fenantreno nos organismos bem como nos extractos de solo dois métodos foram usados: um por fluorescência e outro por cromatografia gasosa com espectometria demassa acoplado. Os resultados obtidos para a bateria de testes mostram uma relação dose-resposta para todas as espécies estudadas, Eisenia andrei é a que demonstra ser mais sensível, com um valor de CE50de aproximadamente 4mg/kg; a sensibilidade para cada espécie por ordem decrescente é a seguinteE. andrei> B. rapa> E. albidus > F. candida > T. aestivum. Verificou-se que os enquitraideos podem acumular e ser afectados por uma variedade decompostos orgânicos e inorgânicos, tais como os HPAs (fenantreno). Os parâmetros cinéticos estimados para o fenantreno foram 4.4 g solo/g organismo dia-1 para a taxa de assimilação (a) e 0,305 dia-1 para a taxa de eliminação (ke), o factor de bioacumulação calculado é de 14.3 para E. albidus.Todos os ensaios foram realizados com um solo padronizado Lufa 2.2. No âmbito geral, os testes ecotoxicológicos realizados, revelam a importânciade incluir diversas espécies, abrangendo diferentes níveis tróficos, devido á distinta sensibilidade dos organismos e modos de acção dos diferentes químicos. ABSTRACT: The usage of chemicalcompounds and their effects in the different environmental compartments have received a special attention in recent years. The occurrence of Personal Care Products (PCPs) in the environment hasbeen recognised as one of emerging issues in environmental chemistry. The widespread presence of PCPs in the environment is due to their extensive usefor direct use by the consumer and incomplete removal in wastewater treatment plants (WWTPs). WWTPs produce aqueous effluents for dischargeback into the environment, and sewage sludge and in a number of cases mayaffect the living organisms. Although Polycyclic Aromatic Compounds (PAHs) have received special attention since they were found in soils for the first time.PAHs are a class of several hundreds individual compounds containing at leasttwo condensed rings. They are produced by the incomplete combustion ofcompounds containing C and H, and diagenesis. With this study we assessed the toxicity of Triclosan in several standardized test organisms and parameters:seed emergence and growth of two terrestrial plants (Triticum aestivum and Brassica rapa); survival and reproduction of earthworms (Eisenia andrei), collembolans (Folsomia candida) andenchytraeids (Enchytraeus albidus). The results for the test battery shows a dose-response relationship for the all organisms tested and Eisenia andreiwas the most sensitive specie, with an EC50value of approximately 4mg/kg; with species chronic sensitivity decreasing from E. andrei > B. rapa > E. albidus > F. candida > T. aestivum. The overall results from the selected ecotoxicologicaltests, showed the importance of including species from different trophic levels due to the different species sensitivities and chemicals mode of action.Moreover, also the use of chronic endpoints is recommended.In the case of the PAH phenantrene (PHE), a study was performed in E. albidus, assessing the effects at the survival and reproduction, plus the bioaccumulation, to analysethe toxicokinetic behaviour of this chemical. Enchytraeus can accumulate and may be affected by PHE. Estimated kinetic parameters were 4.4g soil/g worm day-1 for the assimilation rate (a) and 0,305 day-1 for the elimination rate constant (ke), bioaccumulation factor was 14.3. In a general trend, the ecotoxicological tests performedshow the importance, of study different trophic levels, including different species, due to the different sensibility of the organisms and different chemicals modes of action. 6
Ribeiro, Fabianne de Araújo. "Combined effects of chemicals and ultraviolet radiation on Daphnia magna." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/871.
Full textO ambiente natural está frequentemente exposto a vários tipos de estresses, que podem ser de carácter químico, físico ou biológico, originados da actividade humana e dos processos de alteração climática. Os pesticidas são geralmente usados em práticas agrícolas para controlar doenças em vegetais e o aparecimento de pragas, e podem ser levados do solo para os sistemas aquáticos adjacentes aos locais de aplicação, onde representam um factor de stress para os organismos não-alvo. Além das exposições a químicos, o ambiente está sofrendo as consequências dos processos de alterações climáticas. Uma destas consequências é o aumento da radiação ultravioleta que chega à superfície terrestre devido à diminuição da concentração de ozono na estratosfera. O presente trabalho teve como objectivo principal elucidar alguns padrões e comportamentos biológicos relativamente a mudanças no ambiente. Para isto, com o intuito de prever as interacções entre stressores naturais e químicos, a radiação ultravioleta (RUV) e o fungicida carbendazim foram escolhidos como fontes de stressores natural e químico, respectivamente, e foram aplicados em combinação, como um exemplo das possíveis condições adversas que podem ser encontradas no ambiente. Os efeitos isolados da radiação ultravioleta em Daphnia magna foram avaliados através da utilização de uma lâmpada artificial de RUV, à qual os organismos foram expostos por um período máximo de 5 horas. Os experimentos de combinação entre RUV e carbendazim foram conduzidos com exposição constante ao químico, e uma única dose de radiação ultravioleta. Os parâmetros analisados foram sobrevivência, actividade alimentar, reservas energéticas e produção de juvenis de Daphnia magna. Para prever os efeitos das combinações, um dos modelos utilizados na análise de misturas de químicos e combinação de químicos com stressores naturais foi o utilizado. O modelo da Acção independente (AI) assume que ambos os componentes da combinação têm diferentes modos de acção, e actuam de forma independente sobre o organismo. Os efeitos são avaliados de acordo com as probabilidades de não-resposta do organismo a ambos os componentes da combinação. Há ainda outras formas de interacção entre os componentes da combinação que podem produzir um efeito mais severo (sinergismo) ou menos severo (antagonismo); os efeitos podem ser também dependentes do nível da dose aplicada ou do rácio entre os dois componentes da combinação Os resultados da exposição de Daphnia magna à radiação ultravioleta somente demonstraram um decréscimo na sobrevivência, na actividade alimentar e na produção de juvenis, com valores de dose-efeito muito próximos para todos os parâmetros, o que pode ser explicado pela diferença da sensibilidade deste organismo à radiação, de acordo com a idade em que são expostos. Os resultados das combinações entre carbendazim e RUV para o parâmetro sobrevivência foram bem ajustados ao modelo da acção independente, e não demonstraram nenhum desvio. Para a reprodução e a actividade alimentar, houve um desvio dependente do rácio entre os componentes, que demonstrou maior toxicidade para o carbendazim quando a radiação ultravioleta era o item dominante na combinação. Este estudo mostra a importância da avaliação de combinações entre químicos e stressores naturais. Neste caso, espera-se que o aumento na radiação aumente a sensibilidade dos organismos, como a Daphnia magna quando expostos a stressores químicos, como o fungicida carbendazim.
The natural environment and wildlife are often exposed to several chemicals, physical and biological stressors originated from human activities and climate changes. Pesticides are often used to control plant disease and pest in agricultural practices, and can runoff from the soil to adjacent aquatic systems, where it represents a stress factor for non-target organisms. In addition to chemical exposures, the natural environment is suffering from climate change processes. One of the consequences of that is the increasing amount of ultraviolet radiation reaching the earth’s surface due to depletion on stratospheric ozone. The present work aimed to elucidate some biological behaviors and patterns regarding changes in the environment. For that, to predict interactions between natural stressors and toxicants to Daphnia magna, the ultraviolet radiation (UVR) and the pesticide carbendazim were chosen as the source of natural and chemical stressors, respectively and were employed in combination with each other as an example of possible stress conditions that can be found worldwide in the environment. Single effects of ultraviolet radiation on Daphnia magna were assessed using an artificial UV source, by exposing the organisms to UV and visible light simultaneously, to a maximum period of 5 hours. Combined experiments of carbendazim and ultraviolet radiation were conducted with a constant chemical exposure and a single UVR dose. The parameters analyzed were survival, feeding activity, energy budget and offspring production of Daphnia magna. To predict effects of combined exposures, one of the reference models used for analysis of mixture toxicity and combination of chemical and natural stressor was applied. The Independent Action (IA) model assumes that both components of the combination have different modes of action, and act independently from each other; the effects of the combinations are based on the probabilities of nonresponse of the organism to both stressors. There are some deviations from the independent action model which can cause a more severe effect (synergism), or a less severe effect (antagonism); they might be also dose-level dependent or dose-ratio dependent. Results from single exposure of Daphnia magna to ultraviolet radiation showed a decrease in survival, feeding activity and offspring production, with similar dose-effect values, due to differences in the sensibility of the organism to UVR according to their age. Combined exposures of carbendazim and UVR for survival endpoint fitted to the IA model, showing no deviation patterns, while the response of reproduction and feeding activity were dose-ratio dependent, indicating a higher toxicity of carbendazim when ultraviolet radiation was the dominant item in the combination. This study shows the importance of evaluate the combined effects of chemicals and natural stressors. In this case, UVR increase is expected to enhance the sensitivity of organisms as D. magna when exposed to chemical stressors like the fungicide carbendazim.
Ferreira, Nuno Gonçalo de Carvalho. "The effects of chemicals in isopods: a multi-organizational evaluation." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14095.
Full textThe global aim of this thesis was to evaluate and assess the effects of a pesticide (dimethoate) and a metal (nickel), as model chemicals, within different organization levels, starting at the detoxification pathways (enzymatic biomarkers) and energy costs associated (energy content quantification, energy consumption and CEA) along with the physiological alterations at the individual and population level (mortality), leading to a metabolomic analysis (using liquid 1H-NMR) and finally a gene expression analysis (transcriptome and RT-qPCR analysis). To better understand potential variations in response to stressors, abiotic factors were also assessed in terrestrial isopods such as temperature, soil moisture and UV radiation. The evaluation performed using biochemical biomarkers and energy related parameters showed that increases in temperature might negatively affect the organisms by generating oxidative stress. It also showed that this species is acclimated to environments with low soil moisture, and that in high moisture scenarios there was a short gap between the optimal and adverse conditions that led to increased mortality. As for UV-R, doses nowadays present have shown to induce significant negative impact on these organisms. The long-term exposure to dimethoate showed that besides the neurotoxicity resulting from acetylcholinesterase inhibition, this stressor also caused oxidative stress. This effect was observed for both concentrations used (recommended field dose application and a below EC50 value) and that its combination with different temperatures (20ºC and 25ºC) showed different response patterns. It was also observed that dimethoate’s degradation rate in soils was higher in the presence of isopods. In a similar study performed with nickel, oxidative stress was also observed. But, in the case of this stressor exposure, organisms showed a strategy where the energetic costs necessary for detoxification (biomarkers) seemed to be compensated by positive alterations in the energy related parameters. In this work we presented for the first time a metabolomic profile of terrestrial isopods exposed to stressors (dimethoate and niquel), since until the moment only a previous study was performed on a metabolomic evaluation in nonexposed isopods. In the first part of the study we identify 24 new metabolites that had not been described previously. On the second part of the study a metabolomic profile variation of abstract non-exposed organism throughout the exposure was presented and finally the metabolomic profile of organisms exposed to dimethoate and nickel. The exposure to nickel suggested alteration in growth, moult, haemocyanin and glutathione synthesis, energy pathways and in osmoregulation. As for the exposure to dimethoate alterations in osmoregulation, energy pathways, moult and neurotransmission were also suggested. In this work it was also presented the first full body transcriptome of a terrestrial isopod from the species Porcellionides pruinosus, which will complement the scarce information available for this group of organisms. This transcriptome also served as base for a RNA-Seq and a RT-qPCR analysis. The results of the RNA-Seq analysis performed in organisms exposed to nickel showed that this stressor negatively impacted at the genetic and epigenetic levels, in the trafficking, storage and elimination of metals, generates oxidative stress, inducing neurotoxicity and also affecting reproduction. These results were confirmed through RT-qPCR. As for the impact of dimethoate on these organisms it was only accessed through RT-qPCR and showed oxidative stress, an impact in neurotransmission, in epigenetic markers, DNA repair and cell cycle impairment. This study allowed the design of an Adverse Outcome Pathway draft that can be used further on for legislative purposes.
Os efeitos negativos de contaminantes de origem antropogénica que aparecem no meio ambiente têm um impacto negativo muitas vezes em organismos considerados benéficos. Dentro deste grupo de organismos podemos incluir os isópodes terrestres, detritivorous, cuja função se baseia na fragmentação de matéria vegetal, que poderão posteriormente ser facilmente colonizados por bactérias e os seus nutrientes incorporados nos solos. Para avaliar os efeitos de contaminantes em isópodes terrestres, mais concretamente na espécie Porcellionides pruinosus, foram usados como modelos o metal níquel e o pesticida dimetoato, fazendo uma abordagem em diferentes níveis organizacionais. O trabalho iniciou-se pela avaliação do impacto a nível das vias de destoxificação (biomarcadores enzimáticos) e reservas energéticas (quantificação das reservas, consumo energético e alocação da energia celular), juntamente com alterações a nível dos indivíduos e da população (mortalidade), passando por uma análise de metabolómica (usando 1H-RMN de líquidos) e finalmente uma análise da expressão génica (transcriptoma e RT-qPCR). De forma a melhor entender as variações que podem ocorrer oriundas de variações de fatores abióticos, foi também realizado um estudo sob os efeitos da variação de temperatura, humidade do solo e radiação UV em isópodes terrestres. A avaliação feita a nível dos biomarcadores bioquímicos, quantificação das reservas e parâmetros energéticos demonstrou que o aumento da temperatura iria afectar negativamente os organismos devido ao stress oxidativo gerado. Tendo em conta que esta espécie está aclimatada a ambientes com solos com humidades baixas, a exposição a solos com humidades superiores mostrou a existência de um pequeno intervalo entre o que são consideradas condições óptimas e condições bastante adversas, sendo aí verifica uma elevada mortalidade. Os efeitos da radiação UV demonstraram que as doses que actualmente chegam à superfície do planeta constituem uma ameaça para os isópodes terrestres. A avaliação feita à toxicidade do dimetoato em biomarcadores bioquímicos, reservas e parâmetros energéticos, demonstrou que além da toxicidade já esperada (inibição da enzima acetilcolinesterase), este stressor induz igualmente stress oxidativo. Este efeito foi observado para ambas as concentrações usadas (dose recomendada de aplicação em campo e dose próxima do EC50) e que a sua combinação com diferentes temperaturas (20ºC resumo e 25ºC) dava origem a diferentes padrões de resposta. Também foi observado que a taxa de degradação do dimetoato era superior em solos com a presença de isópodes. Num estudo semelhante ao anterior, realizado com níquel, foi observada toxicidade induzida por stress oxidativo. No entanto os organismos expostos a este stressor apresentam uma estratégia em que os custos energéticos associados à destoxificação (biomarcadores bioquímicos) parecem ser compensados com alterações positivas a nível dos parâmetros energéticos. Neste trabalho é apresentado pela primeira vez o perfil metabolómico de isópodes terrestres expostos a dimetoato e níquel, sendo que até à data apenas um estudo tinha apresentado o perfil metabólico de isópodes em situação de homeostasia. Na primeira parte do estudo é apresentado o perfil metabólico que identifica 24 novos metabolitos que ainda não tinham sido descritos anteriormente. Numa segunda parte é apresentada uma variação do perfil de organismos não expostos ao longo do ensaio e finalmente são apresentadas as variações metabólicas em organismos expostos a dimetoato e a níquel. Os resultados mostraram que ambos os stressores causaram alterações que eram dependentes da concentração e do tempo. Quando expostos a níquel os organismos evidenciam alterações ao nível do crescimento, muda e síntese de hemocianina e glutationas, alterações ao nível das vias energéticas e na osmorregulação. Em relação aos efeitos da exposição a dimetoato, foram observadas alterações a nível da osmorregulação, das vias energéticas e na muda, mas também ao nível da neurotransmissão. Neste trabalho é apresentado pela primeira vez um transcriptoma completo de um isópode terrestre, da espécie Porcellionides pruinosus. Este transcriptoma veio complementar a atual, mas parca, informação disponível sobre este grupo de organismos. Tendo como base o transcriptoma, foi posteriormente realizada uma análise de RNA-Seq e de RT-qPCR. A análise de RNA-Seq foi realizada apenas em organismos expostos a níquel e mostrou que este stressor tem um impacto ao nível genético e epigenético, no transporte, acumulação e eliminação de metais, gera stress oxidativo, neurotoxicidade e afecta também a reprodução. Estes resultados foram confirmados pela análise feita através de RT-qPCR. Em relação aos efeitos de dimetoato nestes organismos a nível genómico, a sua avaliação foi apenas realizada através de RT-qPCR. Foi observado que este stressor gera stress oxidativo, neurotoxicidade, tem um impacto em marcadores epigenéticos, na reparação de ADN e provoca alterações a nível da divisão celular. Este estudo permitiu a realização de uma “Adverse Outcome Pathway” (AOP) que poderá ser usada mais tarde para fins legislativos.
Dann, Andrea B. "The effects of triclosan, 2,4-D, and their by-products on the adrenocortical cells of rainbow trout." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, c2011, 2011. http://hdl.handle.net/10133/3154.
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Davison, Elizabeth L. 1947, and Elizabeth L. 1947 Davison. "Caesalpinia pulcherrima, Calliandra californica, and Justicia specigera: Chemical and environmental regulation of their growth and development." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277127.
Full textBull, Kimberly. "Effects of a commercial pentabrominated diphenyl ether mixture on cholinergic parameters in captive mink." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99325.
Full textHenrico, Daleen (Elsie Magdaleen). "Vergelyking tussen die kodlingmot (Cydia pomonella) se fenologiese ontwikkeling in 'n chemies behandelde-, onbehandelde- en organiese boord in die Wes-Kaap." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50223.
Full textENGLISH ABSTRACT: Codling moth, Cydia pomonella (L.), infested fluit were collected in a sprayed, unsprayed and an organic orchard. The time of emergence was monitored to see if there was selection for a delayed emergence caused by different treatments. Moths from fruit collected in the sprayed and unsprayed orchards in Desember 2001, had a peak emergence during January 2002 and a smaller peak during February 2002. Moths from fruit collected during February 2002 from an organic orchard, had a peak emergence during February 2002 and an extended emergence from diapause until January 2003. Moths from fluit collected during March 2002 had a peak emergence during November 2002 with an extended emergence in the sprayed orchards until January 2003. Delayed emergence from diapause was observed. Not all the moths from diapause emerged during the first flight, but overlapped with the second flight in December and January.
AFRIKAANSE OPSOMMING: Kodlingmot, Cydia pomonella (L.), geïnfesteerde vrugte is in 'n onbespuite, chemies behandelde en 'n organiese boord versamel. Die tyd van motuitkoms is gemonitor om te bepaal of verskillende behandelings dalk seleksie in die motpopulasie kan veroorsaak ten op sigte van 'n vertraagde motuitkoms. Motte uit vrugte wat in die gespuite boorde in Desember 2001 versamel is, het 'n piek uitkoms in Januarie en 'n kleiner een in Februarie 2002 gehad. Motte uit die ongespuite boord se vrugte, het ook 'n piek uitkoms in Januarie 2002 getoon. Motte uit vrugte wat in Februarie 2002 in 'n organiese boord versamel is, het 'n piek uitkoms in Februarie 2002 gehad, met 'n verlengde uitkoms vanuit diapause vanaf Oktober 2002 tot Januarie 2003. Motte uit vrugte wat in Maart 2002 versamel is, het 'n piek uitkoms in November 2002 gehad. Daar was ook 'n verlengde motuitkoms vanaf diapause by die chemies behandelde boorde tot Januarie 2003. 'n Vertraagde motuitkoms vanaf diapause is waargeneem. Die motte vanuit diapause maak nie almal deel uit van die eerste vlug nie, maar oorvleuelook met motte van die tweede vlug wat gedurende Desember en Januarie in die veld voorkom.
Jung, Mun-Yhung. "Effects of carotenoids and tocopherols on the chlorophyll sensitized photooxidation of soybean oil." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1382551295.
Full textAlm, Therese. "Characterization of retention chemicals and their effect on the paper forming process on machine PM4, Billerud Korsnäs Gävle Mill." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-93424.
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