Reclaimed water (treated water discharged from wastewater treatment plants (WWTPs)) is increasingly used in drier regions for irrigation purposes. This effectively increases the water supply and reduces the amount of WWTP discharge into surface waters but it creates the potential for contaminants in the reclaimed water, such as pharmaceuticals and personal care products (PPCPs), to accumulate in exposed crops. The US Environmental Protection Agency (US EPA) considers PPCPs contaminants of emerging concern due to their near universal presence in the environment and their potential for endocrine disruption. Biochar is gaining attention as a soil amendment and could potentially be used to sequester contaminants in the soil thereby reducing the contaminant uptake in crops. The main objective of this study was to investigate the impact of wood biochar on the corn uptake of PPCPs originating from reclaimed water. Biochars derived from regional trees were chosen because they are rapidly expanding and represent a source of forest fire fuel (pinyon and juniper trees) or because they are frequently attacked by insects (lodgepole pine). The impact of biochar on contaminant uptake was tested by growing corn in non-amended soil and soil amended with biochar while being watered with reclaimed water supplemented with PPCPs (1 mg/L). Sand was also used for comparison since it is a less sorptive growth media. After a 28- day growing period, the corn leaves were dried, extracted, and analyzed for PPCPs.

Indiana University-Purdue University Indianapolis (IUPUI) / Insulin-stimulated glucose uptake into skeletal muscle cells requires translocation of the glucose transporter-4 (GLUT4) from the cell interior to the plasma membrane. Insulin-stimulated GLUT4 vesicle translocation is dysregulated in Type 2 diabetes (T2D). The Group I p21–activated kinase (PAK1) is a required element in insulin-stimulated GLUT4 vesicle translocation in mouse skeletal muscle in vivo, although its placement and function(s) in the canonical insulin signaling cascade in skeletal muscle cells, remain undetermined. Therefore, the objective of my project is to determine the molecular mechanism(s) underlying the requirement for PAK1 in the process of insulin-stimulated GLUT4 vesicle translocation and subsequent glucose uptake by skeletal muscle cells. Toward this, my studies demonstrate that the pharmacological inhibition of PAK1 activation blunts insulin-stimulated GLUT4 translocation and subsequent glucose uptake into L6-GLUT4myc skeletal myotubes. Inhibition of PAK1 activation also ablates insulin-stimulated F-actin cytoskeletal remodeling, a process known to be required for mobilizing GLUT4 vesicles to the plasma membrane. Consistent with this mechanism, PAK1 activation was also required for the activation of cofilin, another protein implicated in F-actin remodeling. Interestingly, my studies reveal a novel molecular mechanism involving PAK1 signaling to p41-ARC, a regulatory subunit of the cytoskeletal Arp2/3 complex, and its interactions with another cytoskeletal factor, N-WASP, to elicit the insulin-stimulated F-actin remodeling in skeletal muscle cells. Pharmacological inactivation of N-WASP fully abrogated insulin-stimulated GLUT4 vesicle translocation to the cell surface, coordinate with blunted F-actin remodeling. Furthermore, my studies revealed new insulin-induced interactions amongst N WASP, actin, p41-ARC and PAK1; inactivation of PAK1 signaling blocked these dynamic interactions. Taken together, the above studies demonstrate the significance of PAK1 and its downstream signaling to F-actin remodeling in insulin-stimulated GLUT4 vesicle translocation and glucose uptake, revealing new signaling elements that may prove to be promising targets for future therapeutic design.

Research is presented which encompasses a study of epoxies based on diglycidyl ether of bisphenol A (DGEBA) cured with 2-ethyl-4-methylimidazole (EMI-24) in the presence of the nonionic surfactant Triton X-100. Interest in this epoxy system is due partially to the potential application as a waterborne replacement for solvent cast epoxies in E-glass laminated printed circuit boards. This research has revealed that the viscoelastic behavior of the cured epoxy is altered when serving as the matrix in a glass composite. The additional constraining and coupling of the E-glass fibers to the segmental motion of the epoxy matrix results in an increased level of viscoelastic cooperativity. Current research has determined that the cooperativity of an epoxy/E-glass composite is also sensitive to the surface chemistry of the glass fibers. Model single-ply epoxy/E-glass laminates were constructed in which the glass was pretreated with either 3-aminopropyltriethoxysilane (APS) or 3-glycidoxypropyltrimethoxysilane (GPS) coupling agents. Dynamic mechanical analysis (DMA) was then used to create master curves of the storage modulus (E') in the frequency domain. The frequency range of the master curves and resulting cooperativity plots clearly varied depending on the surface treatment of the glass fibers. It was determined that the surfactant has surprisingly little effect in the observed trends in cooperativity of the composites. However, the changes in cooperativity due to the surface pretreatment of the glass were lessened by the aqueous phase of the waterborne resin. Moisture uptake experiments were also performed on epoxy samples that were filled with spherical glass beads as well as multi-ply laminated composites. No increases in the diffusion constant could be attributed to the surfactant. However, the surfactant did enhance the final equilibrium moisture uptake levels. These equilibrium moisture uptake levels were also sensitive to the surface pretreatment of the E-glass. / Ph. D.

No description available.

No description available.

We hypothesized that estradiol (E2) serves as a neurotrophomodulatory substance for basal forebrain cholinergic neurons thought to be involved in learning and memory. Learning/memory was assessed using the two-way active avoidance paradigm and the Morris water task. Female Sprague-Dawley rats were either ovariectomized (OVX) or OVX for 3 weeks, followed by s.c. implantation of a Silastic pellet containing 17-ß E2 (E2 pellet), resulting in a replacement of E2 to physiological levels. Ovary-intact (INTACT) animals served as our positive control. Active avoidance behavior and choline acetyltransferase (ChAT) activity in the frontal cortex and hippocampus were assessed at 5 and 28 weeks postovariectomy while performance on the Morris water task and high-affinity choline uptake (HACU) were measured only at the 5-week time point. At the 5-week time point, E2 replacement caused a significant elevation in the level of active avoidance performance relative to OVX animals. At the 28-week time point, OVX animals demonstrated a significantly lower number of avoidances relative to controls (61%) whereas E2-pellet animals not only demonstrated superior performance relative to OVX animals but also showed an accelerated rate of learning. Morris water task performance, on the other hand, was not significantly affected by estrogenic milieu despite a trend towards better performance in the E2-pellet group. Neurochemical analyses revealed that 5 weeks of ovariectomy was sufficient to reduce HACU in both the frontal cortex and hippocampus by 24 and 34%, respectively, while E2 replacement was successful in elevating HACU relative to OVX animals in both regions. ChAT activity was decreased in the hippocampus but not the frontal cortex of 5-week OVX animals. E2 replacement resulted in a reversal of this effect. At the 28-week time period, an unexpected decrease in ChAT activity was observed across all treatment groups. Interestingly, E2-pellet animals demonstrated the least severe decline in ChAT. This phenomenon was most evident in the frontal cortex where ChAT decreased by 61 and 56% in INTACT and OVX animals, respectively, whereas the decline in E2-pellet animals was only 16% over the same time period, suggesting a previously unreported cytoprotective effect of E2. Taken together, these findings demonstrate important effects of estrogens on cholinergic neurons and support the potential use of estrogen therapy in treatment of dementias in postmenopausal women.

The purpose of this study was to evaluate increased cardiac output (Q) on oxygen kinetics at exercise intensities above and below the lactate threshold (LT). We hypothesized the increase in Q using head-out water immersion (HOI) while treadmill running would reduce the rate constant of the fast component and reduce the amplitude of the slow component of oxygen kinetics compared with land treadmill running. Subjects (n=10) performed two 6 min exercise bouts at a 15% below and above the LT on a land and underwater treadmill following rest. A single exponential equation [VO2(t) = VO2(b) + A1•(1-e-t/TC1] was used to evaluate VO2. The slow component at the end of exercise was estimated by subtracting (VO2(b) + A1) from the plateau. The mean LT for HOI running 1.80 ± .09 L • min-1 was significantly lower (p < 0.05) than 2.15 ± 1.03 L • min-1 while running on the land. The Q during HOI exercise below and above the LT (16.5 ± 0.6 L • min-1, 18.0 ± 1.2 L • min-1) was significantly higher (p < 0.05) than the Q during exercise below and above the LT on land (11.5 ± 0.8 L • min-1, 13.0 ± 0.7 L • min-1). During HOI exercise below LT time to reach steady-state was delayed (8 ± 2 s). Exercise above LT showed similar phase one time constants for all exercise trials. The amplitude of the slow component was not influenced by HOI. As such, the increase in during HOI exercise did not hastening uptake kinetics.

Second language (L2) learning has begun recognizing that intelligibility, comprehensibility, and accentedness influence how nonnative speakers of English are perceived by others. As such, pronunciation instruction is becoming more common in L2 curriculum around the world. Corrective Feedback (CF) is commonly given in the pronunciation classroom to draw attention to and correct learners’ errors. Research has tried to understand what forms of CF are most effective for language learning, how CF affects pronunciation, and what learners believe about CF. What is lesser known is if the frequency or rate of CF affects learner’s uptake and pronunciation error repair. Participants in this study were nonnative English speakers who were placed in the high frequency feedback group (HFFG) or the low frequency feedback group (LFFG). After an initial demographic and language beliefs survey, participants experienced a one-on-one pronunciation session with a pronunciation researcher. In the pronunciation session, participants received either high frequency feedback (100% of errors corrected) or low frequency feedback (50% of errors corrected defined as every other error corrected). An immediate follow up survey asked learners about their frequency preference for feedback and their emotional reactions to the feedback. After a nonparametric statistical analysis, results indicated that there were no statistically significant differences between the uptake rates of the HFFG and LFFG. Marginal significance was found in the repair rates between the HFFG and LFFG with the LFFG performing marginally better, but not to a statistically significant level. Frequency of CF may affect learners’ error repair rates. The immediate follow up survey indicated that most participants were inaccurate in their perception of the frequency of CF they received during the lesson. Only two participants changed their preference for frequency of CF after the lesson. These two wanted more feedback and no learner wanted less feedback. Finally, the same survey indicated that learners felt mostly positive emotions when receiving feedback, while only two experienced nervousness/anxiousness. Conclusions are that feedback frequency does not seem to affect learner uptake, but that frequency may affect pronunciation error repair.

Water-borne latex coatings represent a safer, more user-friendly, and environmentally responsible alternative to solvent-borne coatings, and are growing in popularity each year. However, these coatings often exhibit unfavorable performance when exposed to water for extended periods of time. This prolonged exposure often results in water uptake, which may give rise to other detrimental effects such as a decrease in modulus, blushing or water-whitening, reduced serviceable life, and softening of the film. In this study, various polymer composition latex design spaces are studied to develop an understanding of how water uptake can be modulated and minimized using common synthetic approaches. Factors including monomer selection, particle size, polymer molecular weight, crosslinking density, surfactant choice and particle stabilization, processing variables and Tg are considered. In addition, some formulation modifications including PVC, film thickness, and choice of coalescent package are explored to gain a more comprehensive understanding of final product performance. In quantifying the total water uptake of the films, gravimetric analysis tends to be the preferred method employed in the coatings industry. However, other analytical approaches can be used to better understand the effect that water has on the properties of the film. These methods may include differential scanning calorimetry, electrochemical impedance spectroscopy, immersion testing using dynamic mechanical analysis, and others. In the work, it has been shown that interparticle crosslinking, surfactant, and monomer selection can have an extreme influence on the water uptake of free films. Film samples exhibit a range of water uptake values from nearly 200% to less than 5% over a one-week soak in deionized water. It is thought that the surfactant may provide hydrophilic channels that allow water to v penetrate the film and form heterogeneous domains within the coating. These domains then grow and scatter light, leading to water-whitening and an increase in mass when compared to the dry film. Utilizing monomers with differing relative solubilities in water, such as methyl methacrylate and styrene, further allow control of this effect. Interparticle crosslinking via keto-hydrazide crosslinking, which is achieved during the film formation process, can also prevent the formation and growth of these large water domains, thus resulting in better performing films.

Iron is one of the most important micronutrients used by living organisms. Iron is frequently a limiting nutrient for plant growth, and plants are a major source of iron for human nutrition. The most prominent symptom of iron deficiency in plants is interveinal chlorosis, or yellowing between the veins, which appears first in the youngest leaves. Iron deficiency anemia (IDA) is the number one human nutritional deficiency worldwide. In order to solve the problem of iron deficiency, it is desirable to breed plants that have increased iron in those parts that are consumed by humans. To do this, we must first understand the molecular basis of Fe uptake, transport, and storage in plants. In soil, iron is quickly oxidized to Fe(III), and Fe(III) is relatively insoluble, thus difficult for plants to obtain. Our lab has been working on metal ion homeostasis mechanisms in plants and the ultimate goal of our research is to understand the mechanisms by which plants maintain the correct levels of iron, zinc and copper in each cell and tissue. The Yellow Stripe-like (YSL) family of proteins has been identified based on sequence similarity to maize Yellow stripe 1 (YS1). YS1 transports Fe(III) that is complexed by phytosiderophores (PS), strong Fe(III) chelators of the mugineic acid family of compounds. Non-grass species of plants neither make nor use PS, yet YSL family members are found in non-grass species including Arabidopsis thaliana. YSLs in non-grasses have been hypothesized to transport metals that are complexed by nicotianamine (NA), an iron chelator that is structurally similar to PS and which is found in all higher plants. In this dissertation, Arabidopsis YSL1 and YSL3 are demonstrated to be important in iron transport and also responsible for loading Fe, Cu, and Zn from leaves into seeds. Arabidopsis YSL4 and YSL6 are demonstrated to be involved in iron transport and metal mobilization into seeds. The transport function of Arabidopsis YSL1 and YSL2 are shown be partially overlapping to the function of Arabidopsis YSL3 in vegetative structures, but distinct in reproductive organs. Arabidopsis YSL3 and YSL6 are shown to have distinct functions in planta.