Ecosystems are disturbed to extract synthetic crude oil from the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada. Successful reclamation of mined oil sands sites depends on maximizing water storage and minimizing the potential for erosion. Soil water repellency in the AOSR affects undisturbed sites and consequently reclamation materials. Extreme water repellency may lead to low infiltration rates and hinder reclamation. There is a lack of information about the naturally occurring and pre-existing levels of soil water repellency in the AOSR. Thus, questions arise about the degree of naturally occurring water repellency and the potential for severe water repellency in reclamation soils. Studies were conducted on nine sites in the AOSR in the summers of 2008 and 2009. A range of undisturbed and reclaimed sites, as well as mineral and organic reclamation materials were examined. Five undisturbed Jack Pine stands (classified as A ecosites), four reclaimed sites and reclamation materials including mineral soil, peat and leaf and lichen covering the forest floor (LFH) were studied. For a comparison of methods, one grasslands site in central Saskatchewan was included. Mini and standard tension infiltrometers were compared as a means of measuring soil water repellency index (RI). There was strong variability in RI values between the infiltrometer methods. The mean RI values from the mini infiltrometers were higher than from the standard infiltrometer (9.61 and 3.46, respectively). The variability within sites dominated the variability in RI for the two methods. Despite these obvious trends, RI values between infiltrometer sizes were statistically different for only two individual sites. Increasing the number of sampling points in the second field season did not reduce the variability. The simpler, less expensive mini infiltrometer is as effective as the standard infiltrometer in measuring soil water repellency. This will enable more efficient and extensive monitoring of soil water repellency in reclaimed and undisturbed sites in the AOSR. Soil water repellency of reclaimed and undisturbed sites was investigated in situ using RI, the water droplet penetration time (WDPT) test, and the molarity of ethanol droplet (MED) test. These measures showed similar trends. Variability in soil water repellency was high at both reclaimed and undisturbed sites. The average RI value for the surface of reclaimed sites was higher than that of the subsurface at reclaimed sites; however, there were no statistical differences between RI values of surface reclaimed and undisturbed sites (P =0.213) due to high spatial variability. The critical water content (CWC) of reclamation materials was determined by measuring the contact angle (CA) and WDPT. Generally, CA and WDPT were inversely related to water content, though variability was high and the relationship between water content was weak. The clearest relationship between water repellency and water content was present for the mineral soil samples. Reclaimed mineral soil was generally wettable above gravimetric water contents of 5-10 %, while the coarse textured tarball affected materials were only subcritically water repellent. There was no relationship between water repellency and water content for peat and LFH. The degree of water repellency was statistically higher for peat materials with increasing decomposition levels. The average WDPT was 44, 128 and 217 s for fibric, mesic, and humic peat, respectively. With careful management and monitoring, water repellency may not be a major limitation to reclamation success. The mini tension infiltrometer is an effective method for monitoring soil water repellency in the AOSR.

Ecosystems are disturbed to extract synthetic crude oil from the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada. Successful reclamation of mined oil sands sites depends on maximizing water storage and minimizing the potential for erosion. Soil water repellency in the AOSR affects undisturbed sites and consequently reclamation materials. Extreme water repellency may lead to low infiltration rates and hinder reclamation. There is a lack of information about the naturally occurring and pre-existing levels of soil water repellency in the AOSR. Thus, questions arise about the degree of naturally occurring water repellency and the potential for severe water repellency in reclamation soils. Studies were conducted on nine sites in the AOSR in the summers of 2008 and 2009. A range of undisturbed and reclaimed sites, as well as mineral and organic reclamation materials were examined. Five undisturbed Jack Pine stands (classified as A ecosites), four reclaimed sites and reclamation materials including mineral soil, peat and leaf and lichen covering the forest floor (LFH) were studied. For a comparison of methods, one grasslands site in central Saskatchewan was included. Mini and standard tension infiltrometers were compared as a means of measuring soil water repellency index (RI). There was strong variability in RI values between the infiltrometer methods. The mean RI values from the mini infiltrometers were higher than from the standard infiltrometer (9.61 and 3.46, respectively). The variability within sites dominated the variability in RI for the two methods. Despite these obvious trends, RI values between infiltrometer sizes were statistically different for only two individual sites. Increasing the number of sampling points in the second field season did not reduce the variability. The simpler, less expensive mini infiltrometer is as effective as the standard infiltrometer in measuring soil water repellency. This will enable more efficient and extensive monitoring of soil water repellency in reclaimed and undisturbed sites in the AOSR. Soil water repellency of reclaimed and undisturbed sites was investigated in situ using RI, the water droplet penetration time (WDPT) test, and the molarity of ethanol droplet (MED) test. These measures showed similar trends. Variability in soil water repellency was high at both reclaimed and undisturbed sites. The average RI value for the surface of reclaimed sites was higher than that of the subsurface at reclaimed sites; however, there were no statistical differences between RI values of surface reclaimed and undisturbed sites (P =0.213) due to high spatial variability. The critical water content (CWC) of reclamation materials was determined by measuring the contact angle (CA) and WDPT. Generally, CA and WDPT were inversely related to water content, though variability was high and the relationship between water content was weak. The clearest relationship between water repellency and water content was present for the mineral soil samples. Reclaimed mineral soil was generally wettable above gravimetric water contents of 5-10 %, while the coarse textured tarball affected materials were only subcritically water repellent. There was no relationship between water repellency and water content for peat and LFH. The degree of water repellency was statistically higher for peat materials with increasing decomposition levels. The average WDPT was 44, 128 and 217 s for fibric, mesic, and humic peat, respectively. With careful management and monitoring, water repellency may not be a major limitation to reclamation success. The mini tension infiltrometer is an effective method for monitoring soil water repellency in the AOSR.

The loss of managed honey bee colonies, resulting from their unintentional exposure to pesticides, is a topic of concern for the agricultural and apicultural industry. Current methods for reducing pesticide exposure to bees involve the application of pesticides before crop bloom or in the evening when foraging bees are less likely to be exposed to these applications. There is an urgent need for additional protection procedures to reduce the annual losses of managed bee colonies. Another method for protecting these pollinators is the use of chemical deterrents to reduce the interaction times of foraging bees with pesticide-treated crops. Historically, insect repellents (IRs) have been used to prevent the spread of deadly human diseases by arthropod vectors. However, it has been shown that bees can be repelled from pesticide-treated crops using DEET and bee pheromonal compounds. Here, I report the toxicological and deterrent effects of bee pheromonal compounds, as well as the deterrent effects of heterocyclic amines (HCAs) on bees. The results of this study indicate that the bee pheromonal compounds, at 8, 20, 60 and 100% concentrations, are toxic to bees and inhibit the feeding of bees within a confined space. Additionally, the pheromonal compounds and the HCAs are as efficacious as DEET in deterring bees from treated food sources. The HCA piperidine was observed to effectively deter bee foragers from a sugar feeder in a high-tunnel experiment as well as from melon flowers and knapweed in field experiments. Electroantennogram recordings were conducted to verify an olfactory response of the bees to the tested compounds. Pheromonal compounds were readily detected by bee antennae; whereas, the HCAs did not elicit significant responses in the bee antennae. These data suggest that bee pheromonal compounds, as well as HCAs, may serve as candidates for the further investigation as repellents to protect bees from unintentional pesticide exposures. / Ph. D.

The common bed bug has reemerged as a major pest in the United States. Pest management professionals need reliable up-to-date information on how to manage bed bug infestations. My study was intended to evaluate the efficacy of several insecticides currently labeled for bed bug control. In product efficacy tests, field strain bed bugs were found to be 99-450 times less susceptible than laboratory strain bed bugs to several pyrethroid products. The non-pyrethroid products tested, chlorfenapyr and a non-toxic desiccant dust, killed laboratory strain bed bugs, but were extremely slow acting taking greater than 9 days to kill 50%. None of the insecticides tested, including the pyrethroids, were repellent to laboratory or field strain bed bugs. A field test was conducted comparing 2 pesticide treatments regimens (traditional and novel) for bed bug control in low income apartments. Both the traditional and novel combinations caused significant reductions in bed bug populations. Both treatments reduced the number of bed bugs by the end of the test period, but neither treatment combination completely eliminated the bed bug infestations, even after an average of 1.3 gallons of product was applied in each apartment. Laboratory assays were conducted to determine the effect of hydroprene exposure on bed bug development. Although hydroprene did not appear to interfere with nymphal development, fifty percent of the bed bugs died during the final molt. The bed bugs which survived to adulthood showed no reduction in fecundity when compared to control groups. / Master of Science in Life Sciences

<p> The objective of this work was to investigate the potential of poly(vinyl pyrrolidone) (PVP) as a protein resistant biomaterial. Two types of PVP surface were studied: (1) plasma polymerized N-vinyl pyrrolidone monomer on polyethylene (PE), and (2) grafted PVP surfaces formed by reaction of the activated polymer with plasma polymerized allyl amine on PE. Surfaces were also prepared by grafting polyethylene oxide (PEO), a known protein repellent, to plasma polymerized allyl amine and for comparison to PVP. The surfaces were characterized chemically by water contact angle and X-ray photoelectron spectroscopy (XPS). Protein interactions were studied using radiolabeled fibrinogen in PBS buffer. </p> <p> Plasma polymerized N-vinyl pyrrolidone surfaces were prepared in a microwave plasma reactor. Reactions were carried out both at room temperature and at 50°C (increased vapour pressure) in an attempt to increase the extent of plasma polymer deposition. The resulting surfaces showed structures chemically different from conventional linear PVP. XPS analysis suggested the presence of a variety of functional groups, including amines, amides, hydroxyls, carbonyls and urethanes. Mechanisms for the reactions occurring could not be ascertained but it appeared that the monomer was extensively fragmented in the plasma. Although these surfaces were hydrophilic (contact angles of 20 to 30°), they did not resist fibrinogen adsorption: in fact they showed adsorption levels approximately 10% greater than unmodified polyethylene. </p> <p> Methods for direct grafting of polyvinyl pyrrolidone and polyethylene oxide to plasma polymerized allyl amine (PPAA) surfaces were designed on the assumption that the PPAA surfaces would be rich in amino groups for reaction with appropriate polymer chain ends. Although there was 8-12% of nitrogen on the surfaces, the C1 s high resolution showed that amide and urethane functionalities are also present in addition to amines. The hydroxyl end groups of preformed PEO and PVP chains were activated by reaction with either 1-[3- (dimethylamino) propyl], 3-ethylcarbodiimide and N-hydroxy succinimide (EDC/NHS), and N-N-disuccinimidyl carbonate (DSC). NMR spectra of the products of these reactions showed that for PEO, the yields were moderate, and for PVP, the yields were low. Surfaces grafted using polymers activated with EDC/NHS were more hydrophilic than surfaces grafted with DSC-activated polymers. XPS data did not provide clear evidence that significant polymer grafting had occurred in any of the systems. It was concluded that changes in the allyl amine plasma polymer in different environments following plasma polymerization may affect the efficiency of grafting subsequently. XPS data suggested that the allyl amine plasma surfaces undergo oxidation over time in air. Also the films may be partly removed from the polyethylene surface when placed in buffer as suggested by XPS and contact angle data. Various parameters were examined in an attempt to improve the allyl amine plasma polymerization process for greater stability of the film. Increasing the treatment time from 1 0 to 30 minutes gave surfaces that showed a slower change in contact angle when stored in air. </p> <p> Despite the lack of strong chemical evidence of extensive polymer grafting, all of the grafted surfaces were found to be significantly protein repellent, with reductions of 10 to 36 % compared to unmodified polyethylene. The PEO surfaces were more repellent than the PVP, although the differences were not significant. Surfaces grafted using polymers activated with EDC/NHS were more protein repellent than those grafted with DSC-activated polymers. Protein adsorption was not affected by PVP molecular weight in the range 2,500 to 10,000. Since there is considerable overlap of the molecular weight distributions (MWD) of these two polymers, it is speculated that the MWDs of the grafted polymers may be more similar than those of the polymers themselves, possibly due to "selection" of similar, presumably optimal molecular weights. </p> <p> Discussion of the possible reasons for the better protein resistance of PEO compared to PVP is given in terms of chain structure in relation to the steric exclusion and water barrier theories of protein repulsion. </p> / Thesis / Master of Applied Science (MASc)

This dissertation represents a unique contribution to the Spanish literature of soil erosion. The author of this document has written and published "Procesos y control de la erosion", a textbook about the engineering of soil erosion processes and the design of the most up-to-date methods and products used for erosion control. The text has been presented in Appendix A.Besides the above, the author of this dissertation is an active committee member at the International Erosion Control Association (IECA), specifically the International Development and the SOIL Fund programs. IECA members are drawn from individuals and erosion control business of different sizes. However, there was a lack of knowledge within IECA members about the formation of post-fire water repellent layers. For instance, Appendix B is represented by an article written by the author of this document, published in Environmental Connection (Volume 2, Issue 3), on July of 2008. The article gives a general description of what post-fire water repellency is, how is it formed, what factors affect it, its consequences on soil erosion, and how to control soil erosion on an efficient way when such a layer has been formed as a consequence of fire.Finally, Appendix C is a research paper in process of submission to the International Journal of Wildland Fire, about the formation of post-fire water repellent layers on Chilean Monterrey pine plantations. Since water repellent layers following wildfires have never been documented on Chilean soils, the need for such a publication is urgent, because Chilean land managers have been ignorant of such phenomenon.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-12-19T13:20:09Z No. of bitstreams: 1 Felipe Fernando da Silva Siqueira.pdf: 863995 bytes, checksum: a843c343f3538b34cd66af25e993bcef (MD5) / Made available in DSpace on 2016-12-19T13:20:09Z (GMT). No. of bitstreams: 1 Felipe Fernando da Silva Siqueira.pdf: 863995 bytes, checksum: a843c343f3538b34cd66af25e993bcef (MD5) Previous issue date: 2013-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The green mite, Mononychellus tanajoa Bondar (Acari: Tetranychidae), is a pest of considerable economic importance for cassava in Brazil, with a wide distribution in South America and in some African countries, due to abiotic conditions (high temperature, relative humidity low), which favor their infestation. The acaricides have been used in its control due to the low technological level of culture that does not compensate for the use of these inputs, as well as the possible side effects caused to applicators, wildlife and the environment. For these reasons, efforts are being made in the search for natural compounds with insecticidal properties and/or miticides. Thus, the present work aimed evaluates the acaricidal activity and repellency of aqueous extracts isolated from plants of the Caatinga Serra Talhada, Pernambuco, to M. tanajoa. The aqueous extracts Croton blanchetianus, Myracrodruon urundeuva, Ziziphus joazeiro were investigated using the immersion technique of cassava leaf disks (3.5 cm diameter) in the tails of the products at the concentrations of 1, 5, 10, 15, 20 and 25%. One evaluated the effects of sublethal extracts using the instantaneous rate of increase (ri) of the population of M. tanajoa, mortality and repellency of adult females. The population growth of M. tanajoa in cassava leaf disks was affected by the aqueous extracts of C. blanchetianus, M. urundeuva and Z. joazeiro at all concentrations tested (1, 5, 10, 15, 20 and 25%), which showed population decline. Just control showed population growth in the ascendancy. Concentrations of 20 and 25% of the extracts showed higher mortality, the most promising for pest control. Furthermore, all concentrations of the extracts showed repellent effect. According to the literature, this is the first recorded use of the extracts of these plants for the control of M. tanajoa. / O ácaro verde, Mononychellus tanajoa Bondar (Acari: Tetranychidae), é praga de considerável importância econômica para a mandioca no Brasil, tendo uma ampla distribuição na América do Sul e em alguns países da África, devido às condições abióticas (temperatura elevada, umidade relativa baixa), que favorecerem a sua infestação. Os acaricidas não têm sido utilizados no seu controle, devido ao baixo nível tecnológico da cultura, que não compensa à utilização destes insumos, bem como, aos possíveis efeitos colaterais causados aos aplicadores, animais silvestres e ao meio ambiente. Por esses motivos, esforços estão sendo empreendidos na procura de compostos de origem natural com propriedades inseticidas e/ou acaricidas. Diante disso, o presente trabalho teve como objetivos avaliar a atividade acaricida e repelência de extratos aquosos isolados de plantas de caatinga de Serra Talhada, Pernambuco, à M. tanajoa. Os extratos aquosos de Croton blanchetianus, Myracrodruon urundeuva, Ziziphus joazeiro foram investigados utilizando-se a técnica de imersão de discos de folha de mandioca (3,5 cm de diâmetro) nas caldas dos produtos, nas concentrações de 1, 5, 10, 15, 20 e 25%. Foram avaliados os efeitos subletais dos extratos, através da taxa instantânea de crescimento (ri) da população de M. tanajoa, a mortalidade de fêmeas adultas e a repelência. O crescimento populacional de M. tanajoa em discos de folhas de mandioca foi afetado pelos extratos aquosos de C. blanchetianus, M. urundeuva e Z. joazeiro em todas as concentrações testadas (1, 5, 10, 15, 20 e 25%), que proporcionaram declínio populacional. Apenas a testemunha apresentou crescimento populacional em ascendência. As concentrações de 20 e 25% dos extratos proporcionaram maior mortalidade, sendo as mais promissoras para o controle da praga. Por outro lado, todas as concentrações dos extratos apresentaram efeito repelente. De acordo com a literatura consultada, este é o primeiro registro do uso dos extratos dessas plantas para o controle de M. tanajoa.

With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, a new method to precisely determine saturated hydraulic conductivity from small intact soil cores collected in the field is demonstrated. This method removes bias due to measurement error using a multiple head linear regression approach. Finally, hundreds of fine spatial scale measurements of soil sorptivity, unsaturated hydraulic conductivity, saturated hydraulic conductivity, soil water content, and other soil descriptive measurements along radial line transects extending out from the trunk of juniper (Juniperus osteosperma) and pinyon pine (Pinus edulis) trees. Within the subcanopy of these trees, interactions among litter material, root distributions, and hydrophobic soil significantly influence ecohydrologic properties by limiting and redirecting infiltration below the soil surface. Consequently, hydrophobicity appears to be a mechanism that promotes survival of woody vegetation in arid environments, through decreasing evaporation rates from the soil surface. We further demonstrate how differences in unsaturated infiltration and soil water content between the subcanopy and intercanopy zones are not discrete. Unsaturated infiltration was significantly lower within the subcanopy than in the intercanopy, and increased by eight-fold across a gradient extending outward from near the edge of the canopy to approximately two times the canopy radius. This gradient was not strongly related to soil moisture. In the intercanopy, increasing structural development of biological soil crust cover beyond this gradient was positivity correlated with infiltration capacity. Consequently, these results indicate that the spatial location of the trees should be considered in the assessment and modeling of woody plant and biological soil crust influence on infiltration capacity in a pinyon-juniper ecosystem.

Betulin is a naturally abundant compound in the outer bark of birch and can be easily obtained by solvent extraction. Herein, solutions of betulin were used to treat cellulosic textile fibers and improve their water repellency. Cotton fabrics impregnated in a 7.5 g L-1 solution of betulin in ethanol showed the highest water contact angle of about 153° while the impregnation in a 3.75 g L-1 solution resulted in a close effect. A terephthaloyl chloride-betulin copolymer was synthesized and dissolved in tetrahydrofuran to afford a solution with a concentration of 3.75 g L-1. The cotton fabric impregnated in this solution showed a water contact angle of 150°. Changes in morphology of the cellulose fibers before and after the treatment were observed by scanning electron microscopy, and the water repellency was measured by a standard spray test. The marketing strategy of the potential product, which will be developed based on this technique, was discussed.

The Rodeo-Chediski Wildfire the largest in Arizona's history at the time of burning damaged and disrupted ecosystems resources and functioning in a largely mosaic pattern throughout the ponderosa pine (Pinus Ponderosa) forests exposed to the burn. Impacts of this wildfire on ecosystems resources and functioning were studied from shortly after the cessation of the wildfire in late summer of 2002 through the spring of 2007 on two previously instrumented watersheds located on sandstone derived soils within the burn. One watershed was burned by a high severity (stand-replacing fire), while the other watershed burned in a low severity (stand-modifying) fire. This dissertation focuses on the effects fire severity had on watersheds resources and functioning in terms of the tree overstories, herbaceous understories, large and small mammals, avifauna, hydrologic functioning, soil water repellency, hillslope soil movement, and fuel loadings. The results of these studies indicated the cumulative impacts incurred to ecosystem resources, hydrologic functioning, and flammable fuels were much greater on the watershed exposed to the high severity (stand-replacing) fire. It is anticipated that the overall ecological and hydrologic function on the watershed burned by a high severity will not approach pre-fire conditions for many years. The watershed burned at a low severity, however, was approaching pre-fire conditions nearly five years after fire and is expected to be recovered within the next few years.