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Wood products all require treatment to mitigate phytosanitary risk prior to exportation. The most common phytosanitary treatment applied to Pinus radiata logs is Methyl Bromide (MeBr). The Environmental Protection Agency (EPA) in 2010 stated that MeBr must not be release into the atmosphere past 2020. This poses a problem for New Zealand log exports. Radiation has been identified as a possible alternative phytosanitary treatment for export wood products. This study aimed to quantify the effective dose of radiation necessary to sterilise two forest pest species; Arhopalus ferus and Hylurgus ligniperda. These species are representative of two different types of forestry pests; bark beetles (H. ligniperda) and wood borers (A. ferus). All applicable life stages for both species were tested. Arhopalus ferus adults were the most susceptible life stage identified with an LD99 of 30.2Gy ± 13.5 Gy (95% confidence interval). Arhopalus ferus eggs were less susceptible with a LD99 of 750Gy ± 776Gy observed; however there is low confidence in this result due to a methodological issue in one treatment replicate. Hylurgus ligniperda eggs were observed to be less susceptible than A. ferus eggs with a LD99 of 289Gy ± 92Gy. Results for the other life stages were inconclusive due to poor control survival, however the information gained was used to develop improved methods for further experimentation, which is on-going and showing positive results so far. The results of this experiment have indicated that radiation can be an effective method of sterilising forestry pests. To date radiation has not been used as phytosanitary risk mitigation for wood exports; however it is widely used for risk mitigation in agricultural products. Currently there remains a large amount of unknown information regarding, the effectiveness for irradiation of logs, the effective dose require for sterilisation of the most tolerant forestry pest and public acceptability of irradiation as a phytosanitary treatment. These knowledge gaps and an economic assessment must be completed before irradiation can be used as a phytosanitary risk mitigation technique for forestry products.

Issues of Disinfection By-Product (DBP) formation in response to chlorination in drinking water treatment systems is a common issue encountered by WTP operators. Efforts to minimize DBP formation are complicated by the presence of zebra mussels, which may inhabit the raw water intake of WTPs. While chlorination at the intake to control zebra mussel populations is effective, the formation of DBPs is exacerbated. Methods for reducing DBPs are explored, including adjusting the location for chlorine additions in the treatment sequence. Multivariate models for Total Trihalomethane (TTHM) and Haloacetic Acid (HAA) subspecies are employed to show that in some instances pre-chlorination can be reduced to lower DBP formation, while post-chlorination can be increased. A Regression model (R2 of 0.75) predicts that DBP levels can be lowered by post-chlorination rather than pre-chlorinating raw water for portions of the year except during the combatable life stage to assist in zebra mussel control. A second multivariate regression model for TTHM (R2 = 0.91) which includes bromide, a variable which, due to lack of data, was previously unused, is described and demonstrates that DBP levels can be reduced by lowering pre-chlorination levels. Finally, a Bayesian network is developed using the Webweavr-IV Toolkit, utilizing causal relationships between raw water quality parameters in the form of conditional probabilities. The results show that the average cancer risk can be decreased by while still maintaining zebra mussel control and simultaneously decreasing the incremental cancer risk, which currently fluctuates between 1 in 50,000 to 100,000 in Ontario. / Canada Research Chair Program, Ontario Research Foundation

Spatial variability of soil properties complicates the understanding of water and solute transport at the field scale. This study evaluated the impact of land use, soil surface roughness, and rainfall characteristics on water transport and Br- leaching under field conditions by means of a new experimental design employing scale-dependent treatment distribution. On a transect with two land use systems, i.e., cropland and grassland, rainfall intensity and the time delay between Br- application and subsequent rainfall were arranged in a periodically repetitive pattern at two different scales. Both scales were distinct from the scale of surface roughness as described by elevation variance. Nests of tensiometers and suction probes were installed at 1-m intervals along the transect to monitor matric potentials and Br- concentrations at different depths, respectively. After rainfall simulation, soil samples were collected at every 0.5 m horizontal distance in 10 cm vertical increments down to 1 m depth for Br- analysis. Soil Br- concentration was more evenly distributed with soil depth and leached deeper in grassland than cropland, owing to vertically continuous macropores that supported preferential flow. Frequency-domain analysis and autoregressive state-space approach revealed that the dominant factors controlling Br- leaching varied with depth. In shallow layers, land use was the main driving force for Br- distribution. Beyond that, the spatial pattern of Br- was mostly affected by rainfall characteristics. Below 40 cm, the horizontal distribution of Br- was dominated by soil texture and to a smaller extent by rainfall intensity. Bromide concentrations obtained from soil solution samples that were collected through suction probes showed similar results with respect to the influence of rainfall intensity. The spatial variation scale of temporal matric potential change varied with both time and depth, corresponding to different boundary condition scales. Matric potential change in some cases, reflected the impact of soil properties other than the boundary conditions investigated, such as hydraulic conductivity, contributing to the scale-variant behavior of Br- leaching. These findings suggest the applicability of scale-dependent treatment distribution in designing field experiments and also hold important implications for agricultural management and hydrological modelling.

Rapid and deep transport of solutes in soils can potentially pollute groundwater resources. Field estimates of solute leaching depth based on randomized sampling provide extremely variable field average estimates that confound the treatment effects of the leaching study with the high spatial variation of soil hydraulic properties. The purpose of this study was to investigate the spatial scale of variation of solute (Bromide) leaching depth, and apply this scale of variation to study the leaching depth of Bromide as a function of a sinusoidal application of transport causing factors, i.e., rainfall amount, intensity and application time delay. Solute leaching depth varied over different spatial scales. The deepest leaching was observed on plots where the Br center of mass ranged from 19-30 cm depth. Deep leaching occurred with large quantities of low intensity precipitations (5.5 to 6 cm/day) and short time delays (≤ 17 hours), respectively. The hydraulic gradient presented cyclic variation at 8 m wavelength across the 10-30cm depth compartment. Spectral analysis indicated that spatial variation of the leaching depth was mainly affected by precipitation amount and intensity and only a small portion of the leaching depth variation was caused by time delay. Cross-spectral analysis identified common cyclic variation between the Br leaching depth and precipitation amount, intensity and time delay over 32, 32 and 8 m wavelengths, respectively. Simulated Br concentration over depth and horizontal distance and soil water matric potential ψm were in good agreement with experimental observations, the latter revealing a satisfactory Br and water mass balance.

This thesis presents a method for a small, inexpensive mobile robot equipped with a single high resolution scintillation detector to quickly survey an area and convey information about local sources of gamma radiation to a remote human operator. This is achieved by surrounding the detector with a lead sheath that blocks all gamma rays except those incident along the detector???s axial direction. A horizontal scan is performed by rotating the detector and a directional profile of gamma radiation is constructed. In addition a visual panorama of the local area is assembled using a camera mounted on the detector. A plot of the detector signal versus angle is then overlaid on top of the visual panorama and visible peaks clearly indicate the direction of local gamma radiation sources. Moreover, measuring the energy spectrum of gamma rays in each direction produces a 2D count frequency histogram where distinct peaks indicate the energy and direction of local gamma ray sources allowing the identification of different radio-isotopes.

Source water quality plays a critical role in maintaining the quality and supply of drinking water, yet it can be negatively affected by human activities. In Pennsylvania, coal mining and treatment of conventional oil and gas drilling produced wastewaters have affected source water quality for over 100 years. The recent unconventional natural gas development in the Marcellus Shale formation produces significant volumes of wastewater containing bromide and has the potential to affect source water quality and downstream drinking water quality. Wastewater from coal-fired power plants also contains bromide that may be released into source water. Increasing source water bromide presents a challenge as even small amounts of bromide in source water can lead to carcinogenic disinfection by-products (DBPs) in chlorinated finished drinking water. However, bromide is not regulated in source water and is not removed by conventional drinking water treatment processes. The objective of this work is to evaluate the safe bromide concentration in source water to minimize the cancer risk of trihalomethanes - a group of DBPs - in treated drinking water. By evaluating three years of water sampling data from the Monongahela River in Southwestern Pennsylvania, the present analysis reached three conclusions. First, bromide monitoring for source water quality should be taken at drinking water intake points. Water sample types (river water samples vs drinking water intake samples) can lead to different water quality conclusions and thus affect regulatory compliance decision-making. Second, bromide monitoring at drinking water intake points can serve as a predictor for changes in heavily brominated trihalomethanes concentrations in finished water. Increasing bromide in source water can serve as an early warning sign of increasing formation of heavily brominated trihalomethanes and their associated cancer risks in drinking water. Finally, this work developed a statistical simulation model to evaluate the effect of source water bromide on trihalomethane formation and speciation and to analyze the changing cancer risks in water associated with these changing bromide concentrations in the Monongahela River. The statistical simulation method proposed in this work leads to the conclusion that the bromide concentration in source water must be very low to prevent the adverse health effects associated with brominated trihalomethanes in chlorinated drinking water. This method can be used by water utilities to determine the bromide concentration in their source water that might indicate a need for process changes or by regulatory agencies to evaluate source water bromide issues.

Increasing concern about the pollution of environment by inorganic and organic chemicals arising from naturally occurring ecological events and industrial processes has created a need for the search of new techniques in the removal of these contaminants. One of the natural material that can be used in such processes is clay. Clay minerals have large surface areas and high cation exchange capacities which enables them to be modified by cationic surfactants. The material prepared, often called as &amp / #8216 / organoclay&amp / #8217 / , can be used to remove hydrophobic organic and anionic contaminants from polluted water. Among the anionic contaminants, oxyanions such as nitrate, chromate are detrimental to human life and environment even at &micro / g/L- mg/L levels. Application of organoclays for their removal from polluted water appears as one of the practical and rather cheap solution. In this study, a local clay from Ankara-Kalecik (Han&ccedil / ili Bentonite) was modified by hexadecyltrimethylammonium bromide (HDTMA-Br) to a level of twice of its cation exchange capacity. This process alters the negatively charged surface of the clay into a positively charged one, providing sites for the removal of anionic contaminants. In this study, the degree of HDTMA+ uptake by the clay within a period of eight hours is found to be 97% of the initial amount added. In desorption studies it was revealed that only about 1% of the sorbed HTDMA+ was leached in a seven days of water-organoclay interaction revealing a rather stable organoclay structure in aqeous media. Sorption experiments with nitrate, borate, and chromate solutions were performed in order to determine the anion sorption capacity of the organoclays prepared. It turns out that while untreated clay has insignificant capacity, the modified clay can remove considerable amount of nitrate and chromate ions from aqeous solutions. While the nitrate sorption was increased about eleven fold, change in chromate sorption was reached to a level of twenty fold compared to that of the untreated clay. Sorption data for nitrate and chromate are both well described by the Langmuir isotherms. No significant change was observed in case of borate-organoclay interaction. Desorption of nitrate and chromate ions from organoclay surface were also investigated. Sorption of these oxyanions were found to be almost irreversible in aqeous media. The results imply that a properly prepared organoclay can be used for the removal of oxyanions, such as nitrate and chromate from polluted water systems.

A esclerose múltipla é a principal doença desmielinizante do sistema nervoso central (SNC). É considerada a principal causa de incapacidade neurológica em adultos jovens. O comprometimento cognitivo é muito comum nessa doença, envolvendo o aprendizado, a memória e a organização cortical do movimento, funções vitais que são reguladas pelo sistema colinérgico. O modelo de desmielinização tóxica induzida pelo brometo de etídio (BE) foi utilizado neste estudo, para avaliar a atividade da enzima acetilcolinesterase (AChE) no estriado (ST), hipocampo (HP), córtex cerebral (CC), hipotálamo (HY) e ponte (PN) associado ao tratamento com interferon beta (IFN-b), ciclosporina A (CsA), vitamina E (vit E) e ebselen (Ebs). Além disso, também foi investigado o efeito in vitro do BE na atividade da AChE, juntamente com os parâmetros cinéticos dessa enzima no ST, HP, CC e CB de ratos adultos. Os resultados demonstraram que o BE inibiu significativamente a atividade da AChE no ST, HP, CC e CB nas concentrações de 0,00625, 0,0125, 0,025, 0,05 e 0,1mM e a análise dos dados cinéticos mostraram uma inibição do tipo incompetitiva no ST, HP e CC, enquanto no CB a inibição foi do tipo mista. No estudo in vivo, foi observado uma inibição na atividade da AChE no CC, ST, HP, HY, PN e CB nos diferentes períodos avaliados pós-injeção do BE (3, 7, 15, 21 e 30 dias). Quando ratos desmielinizados com BE foram tratados com IFN-b e CsA, não houve alteração na atividade dessa enzima. Por outro lado, o tratamento com Vit E e Ebs foram capazes de aumentar a atividade da AChE no ST, CC e HP. Estudos imuno-histoquímicos demonstraram que nos ratos tratados com Vit E e Ebs as lesões induzidas pelo BE foram menores, sugerindo que estes compostos interferem no desenvolvimento de lesões desmielinizantes. Foi também avaliado o efeito per se do IFN-b, da CsA, da Vit E e do Ebs na atividade da AChE, os quais demonstraram um efeito inibitório sobre a atividade dessa enzima. Em plaquetas de ratos desmielinizados, foi observado uma diminuição na atividade da NTPDase e o tratamento com a Vit E e o Ebs modularam a hidrólise dos nucleotídeos de adenina. O presente trabalho demonstrou que o BE é um potente inibidor da atividade da AChE in vitro e os resultados in vivo demonstraram que a atividade dessa enzima está alterada após um evento de desmielinização tóxica no SNC. Os resultados deste estudo ajudaram a confirmar que drogas utilizadas no tratamento de pacientes com esclerose múltipla tais como o IFN-b e a CsA causam efeitos na atividade da AChE. A Vit E e o Ebs, além de demonstrarem uma interação com a neurotransmissão colinérgica, também modularam a hidrólise dos nucleotídeos de adenina em plaquetas de ratos, contribuindo no controle da coagulação plaquetária em processos desmielinizantes. Neste contexto, sugere-se que o IFN-b, a CsA, a vitamina E e o ebselen podem ser investigados em estudos futuros com a intenção de encontrar uma melhor terapia para beneficiar pacientes com patologias desmielinizantes. / Multiple sclerosis is the main demyelinating disease of the central nervous system (CNS). It is the most common cause of neurological disability among young adults. The cognitive impairment is very commum in this illness, involving learning, memory and cortical organization of the movement, vital functions regulated by the cholinergic system. The model of toxic demyelination induced by ethidium bromide (EB) was used to evaluate brain acetylcholinesterase (AChE) activity in the striatum (ST), hippocampus (HP), cerebral cortex (CC), cerebellum (CB), hypothalamus (HY) and pons (PN), associated with treatment with interferon beta (IFN-b), ciclosporine A (CsA), vitamin E (Vit E) and ebselen (Ebs). In addition, the per se effect of EB on AChE activity was studied in vitro together with the kinetic parameters of this enzyme in the ST, HP, CC and CB of adult rats. The results showed that EB in vitro significantly inhibited AChE activity in the ST, HP, CC and CB at concentrations of 0.00625, 0.0125, 0.025, 0.05 and 0.1mM. The kinetic analysis demonstrated an uncompetitive inhibition in the ST, HP and CC, whereas in the CB the inhibition type was mixed. In relation to the in vivo results, AChE activity was inhibited after demyelination by EB in the CC, ST, HP, HY, PN and CB at the post-injection points of time evaluated (3-7-15-21 and 30 days). When demyelinated rats were submitted to the treatment with IFN-b and CsA, the results demonstrated that these compounds did not alter AChE activity. However, Vit E and Ebs were able to increase AChE activity in the ST, CC and HP. In addition, immunohistochemistry studies demonstrated that in Vit E and Ebs treated rats, the lesions induced by EB were smaller suggesting that these compounds somehow interfered in the development of the lesions. The per se effect of IFN-b, CsA, Vit E and Ebs were also evaluated, demonstrating that these compounds have an inhibitory effect on AChE activity. Platelets of the demyelinated rats demonstrated a reduction in NTPDase activity and the treatments with Ebs and Vit E modulated adenine nucleotide hydrolysis. The present investigation demonstrated that EB is a strong inhibitor of AChE activity in vitro and the results in vivo showed that the activity of this enzyme is altered after an event of toxic demyelination in the CNS. The results this study help the confirm that drugs used in the treatment of the patients with multiple sclerosis such as IFN-b and CsA cause effects in the AChE activity. The Vit E and Ebs besides of interaction with the cholinergic neurotransmission also modulated adenine nucleotide hydrolysis in platelets of the rats, contributing to the control of the platelet coagulant status in the demyelinating process. In this context, we can suggest that IFN-b, CsA, Vit E and Ebs may be investigated in future studies with the intention of finding a better therapy for to improve patients with demyelinating pathologies.

Made available in DSpace on 2014-06-11T19:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-04-19Bitstream added on 2014-06-13T20:26:03Z : No. of bitstreams: 1 fonseca_jcl_dr_araiq.pdf: 990419 bytes, checksum: e085f09b617e177af79386bb8d35d879 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Substâncias perigosas são freqüentemente utilizadas em laboratórios de ensino e pesquisa das Universidades. Até pouco tempo não existia preocupação com o destino destas substâncias após o uso. Tinha-se a falsa idéia de que como a Universidade utiliza poucas quantidades, de diferentes produtos, seu efeito ao ambiente era irrelevante. Felizmente atualmente este cenário é outro e as Universidades estão implementando programas de gerenciamento e em alguns poucos casos, de tratamento de resíduos. Diferentemente de agentes biológicos, substâncias químicas não possuem um procedimento de degradação que seja eficaz às diferentes classes e é necessário o desenvolvimento de diferentes métodos para diferentes produtos. Este trabalho adaptou métodos degradativos apresentados na literatura à três substâncias, escolhidas por sua toxicidade e pelo volume gerado anualmente das mesmas: brometo de etídeo (BE), formaldeído e fenol. A degradação do BE foi monitorada por fluorescência e pela concentração de Carbono Orgânico Total (COT), como BE é mutagênico seu produto de degradação foi submetido ao teste de mutação gênica com Salmonella thiphimurium (teste de Ames) utilizando as linhagens TA97a, TA98 e TA100, para avaliar se havia perdido esta característica. Observou-se que embora todos os tratamentos apresentassem a mesma resposta quanto a fluorescência, o ensaio mutagênico mostrou que apenas dois procedimentos poderiam ser realmente empregados. Os demais resíduos (fenol e formaldeído) tiveram seus produtos de degradação avaliados por COT e segundo as premissas da legislação estadual para efluentes em ambos os casos os resíduos apresentaram uma boa redução da carga orgânica. A toxicidade dos produtos formados foi avaliada por testes ecotoxicológicos (Daphna magna) e como todo formaldeído e fenol foram oxidados essa propriedade foi efetivamente eliminada. / Hazardous substances often have been used in university teaching and researching laboratories as well. Few years ago there was not the concern about the destiny of these substances after their application. There was the wrong concept as the university use a few quantities of different kind of products, the behavior of these products in the environment were insignificant. Fortunately, nowadays the context has changed and the universities have established management programs of waste treatment. Distinctly of biological agents, chemicals substances do not have a model is better (or pattern) of destruction efficient to so many categories or types. So it is necessary the development of different methods for different products. This present work adjusted degradative methods presented on the literature for three different substances, chosen by their toxicity and quantity yearly storage: ethidium bromide (EB); formaldehyde and phenol. The degradation of EB was observed by fluorescence and by total carbon organic concentration, as BE is mutagenic, its degradation product was submitted to mutagenicity test with Salmonella thiphimurium (Ames test) using TA97a, TA98 and TA100, for evaluate original characteristics. The obtained data shown that although all of treatments presented the same answer for the fluorescence, the mutagenic assay has shown that just two methods could be efficiently used. The another products (phenol and formaldehyde) have had yours degradatives products evaluated by TOC according the supposition from the state legislation for wastewater, in both cases the results data shown reduction organic The toxicity of products in this case were evaluated by ecotoxicological tests (Daphnia magna), as all formaldehyde and phenol have been oxidized the toxicity was banished. Even tough the results obtained shown that methods are simple and could be applied for own creators in situ, just follow the methods shown in these work.