The Delicacy of Social Relationships: How Seemingly Small Choices In Formulating Talk Can Have Large Consequences For Relationships

This thesis demonstrates that relationships are constantly being reproduced in every moment of interaction. Talk is the way relationships are reproduced, thus both relationships and talk are dependent on one another. The following analysis discusses four distinct aspects of social action: (1) preference organization, (2) taboo talk, (3) laughter, and (4) repair

The influence of water quality on wetland-associated microbial communities

Within a wetland environment, bacteria in association with plant roots play a vital role in maintaining the health of freshwater ecosystems. In order to gain insight into the stability and processes occurring within natural and constructed wetland environments we need to develop a better understanding of the relationship between wetland plants, root-associated microbial communities and environmental factors. Human population growth and urbanization have resulted in greater contaminant loads (inorganic nutrients, fecal contamination etc.) entering our waterways. As such, we need a better understanding of how anthropogenic impacts influence the structure and function of the wetland-associated microbial communities that we rely on to maintain the integrity of our freshwater ecosystems. To meet this need we designed a series of experiments to investigate the hypothesis that wetland-associated microbial communities highly impacted by anthropogenic activities subjected to poor water quality inputs (high inorganic nutrient load) would differ from less impacted communities in terms of community structure, function, remedial capabilities and resilience. Furthermore, we hypothesized that plant species would play a role in how the associated microbial community would respond to these differences in water quality. To investigate these hypotheses we used a multi-faceted approach involving both in situ field-based studies (Grand River, ON) and ex situ lab-scale wetland mesocosm studies. We examined microbial communities in association with several different plant species (Phalaris arundinacea, Iris versicolor, Potamogeton natans and Veronica spicata) across field sampling locations (Grand River, ON). Lab-scale mesocosm studies involved sub-surface flow wetland mesocosms planted with either P. arundinacea or V. anagallis-aquatica receiving water from sites with contrasting water quality charactersitics. To ascertain the ability of the microbial communities associated with these mesocosm treatments to resist environmental perturbations, mesocosms were exposed to 5mg/L of inorganic phosphorus to simulate runoff from a rain event. We used PCR in combination with denaturing gradient gel electrophoresis (DGGE) to examine the structure of microbial communities in association with wetland plant roots and water-associated communities. Functional community characteristics were examined by obtaining community-level carbon source utilization patterns with BiologTM EcoPlates. We examined the influence of water quality and plant species on fecal contamination associated microbial pathogens by enumerating fecal coliforms as well as Salmonella spp., Escherichia coli and Enterococcus spp. specifically, from water and root-associated microbial communities using the membrane fecal coliform method and quantitative real-time PCR. The remediation potential of ex situ mesocosm-based microbial communities experiencing different water quality treatments in association with our study plant species were determined by quantifying inorganic nitrogen and phosphorus concentrations from mesocosm outflow water. From our field-based studies we found that the structure and function of microbial communities in association with wetland plant roots was affected by sampling location, however this effect was dependent on the plant species in question as well as the root-associated community type (rhizoplane or rhizosphere). Furthermore, plant species differed in their retention of microbial DNA from fecal contamination associated microorganisms. Our ex situ mesocosm-based wetland studies yielded comparable results. We found that the root-associated microbial communities from P. arundinacea and V. anagallis-aquatica were altered structurally and functionally by the different water quality treatments. However, functional characteristics of P. arundinacea-associated communities were affected by water quality treatment to a greater extent than those communities associated with V. anagallis-aquatica. Furthermore, the influence of water quality treatment on microbial community structure and function differed by community type. Rhizoplane-associated microbial communities exhibited the most dramatic structural and functional changes when challenged with varying water quality treatments. Exposure to short-term phosphorus loading as 5 mg/L of inorganic phosphorus resulted in changes to microbial community structure and function in both plant species-associated microbial communities, most notably within the rhizoplane. Structural and functional community diversity was reduced following the inorganic phosphorus treatment for rhizoplane-associated microbial communities. Both mesocosm-based wetland communities performed equally well at removing inorganic nutrient loads from the various water quality sources

The Role of Morphology in Diet and Flower Visitation by Five Species of Cuban Flower-Visiting Bats

Pollinator and flower morphology are important factors in structuring the plant-pollinator relationship. A pollinator’s morphology may influence aspects of its diet. Flower-visiting bats are an important pollinator group but very little is known about what influences their interactions with food plants. I examined the role of morphology in the partitioning of food resources for five species of flower-visiting Cuban bats. I analyzed cranial traits and body size to examine differences among species and to determine the degree of morphological specialization for flower-feeding for each species. I also collected dietary data from guano and used acoustic monitoring to assess bat activity at flowers. I found evidence of partitioning of plant resources among the bat species, although evidence of limiting resources was not observed. Morphological similarity between species did not predict dietary overlap. However, species differing in their morphological specialization for flower-feeding consumed resources and visited food plants at different frequencies

The influence of water quality on wetland-associated microbial communities

Within a wetland environment, bacteria in association with plant roots play a vital role in maintaining the health of freshwater ecosystems. In order to gain insight into the stability and processes occurring within natural and constructed wetland environments we need to develop a better understanding of the relationship between wetland plants, root-associated microbial communities and environmental factors. Human population growth and urbanization have resulted in greater contaminant loads (inorganic nutrients, fecal contamination etc.) entering our waterways. As such, we need a better understanding of how anthropogenic impacts influence the structure and function of the wetland-associated microbial communities that we rely on to maintain the integrity of our freshwater ecosystems. To meet this need we designed a series of experiments to investigate the hypothesis that wetland-associated microbial communities highly impacted by anthropogenic activities subjected to poor water quality inputs (high inorganic nutrient load) would differ from less impacted communities in terms of community structure, function, remedial capabilities and resilience. Furthermore, we hypothesized that plant species would play a role in how the associated microbial community would respond to these differences in water quality. To investigate these hypotheses we used a multi-faceted approach involving both in situ field-based studies (Grand River, ON) and ex situ lab-scale wetland mesocosm studies. We examined microbial communities in association with several different plant species (Phalaris arundinacea, Iris versicolor, Potamogeton natans and Veronica spicata) across field sampling locations (Grand River, ON). Lab-scale mesocosm studies involved sub-surface flow wetland mesocosms planted with either P. arundinacea or V. anagallis-aquatica receiving water from sites with contrasting water quality charactersitics. To ascertain the ability of the microbial communities associated with these mesocosm treatments to resist environmental perturbations, mesocosms were exposed to 5mg/L of inorganic phosphorus to simulate runoff from a rain event. We used PCR in combination with denaturing gradient gel electrophoresis (DGGE) to examine the structure of microbial communities in association with wetland plant roots and water-associated communities. Functional community characteristics were examined by obtaining community-level carbon source utilization patterns with BiologTM EcoPlates. We examined the influence of water quality and plant species on fecal contamination associated microbial pathogens by enumerating fecal coliforms as well as Salmonella spp., Escherichia coli and Enterococcus spp. specifically, from water and root-associated microbial communities using the membrane fecal coliform method and quantitative real-time PCR. The remediation potential of ex situ mesocosm-based microbial communities experiencing different water quality treatments in association with our study plant species were determined by quantifying inorganic nitrogen and phosphorus concentrations from mesocosm outflow water. From our field-based studies we found that the structure and function of microbial communities in association with wetland plant roots was affected by sampling location, however this effect was dependent on the plant species in question as well as the root-associated community type (rhizoplane or rhizosphere). Furthermore, plant species differed in their retention of microbial DNA from fecal contamination associated microorganisms. Our ex situ mesocosm-based wetland studies yielded comparable results. We found that the root-associated microbial communities from P. arundinacea and V. anagallis-aquatica were altered structurally and functionally by the different water quality treatments. However, functional characteristics of P. arundinacea-associated communities were affected by water quality treatment to a greater extent than those communities associated with V. anagallis-aquatica. Furthermore, the influence of water quality treatment on microbial community structure and function differed by community type. Rhizoplane-associated microbial communities exhibited the most dramatic structural and functional changes when challenged with varying water quality treatments. Exposure to short-term phosphorus loading as 5 mg/L of inorganic phosphorus resulted in changes to microbial community structure and function in both plant species-associated microbial communities, most notably within the rhizoplane. Structural and functional community diversity was reduced following the inorganic phosphorus treatment for rhizoplane-associated microbial communities. Both mesocosm-based wetland communities performed equally well at removing inorganic nutrient loads from the various water quality sources

Transport of Nucleotide Derivatives into Endoplasmic Reticulum and Golgiapparatus Derived Vesicles: a Dissertation

In mammals, newly synthesized proteins destined for secretion are translocated cotranslationally into the lumen of the Endoplasmic Reticulum (ER). Once inside, these nascent polypeptide chains are bound by a lumenal ER protein called BiP (Immunoglobulin Binding Protein) or Grp 78 (Glucose Regulated Protein 78). It is hypothesized that this binding is necessary to protect the nascent chains until they are properly folded or assembled with other subunits. When the proteins are folded and assembled, they are released from BiP by a process that is dependent on ATP hydrolysis. Since ATP is synthesized mainly in the mitochondria, we hypothesized that there must be an ATP transporter in the ER which would allow the protein mediated transport of ATP from the cytosol into the ER lumen. We studied the transport of ATP in vitro and found that ATP enters the lumen of the ER in a saturable manner with a Kmapp~3μM. ATP transport is dependent on time, protein, and vesicle integrity, it is also inhibited by the general anion transport inhibitor, 4,4\u27 diisothiocyano-2,2\u27-disulfonic acid stilbene (DIDS). We also found that the transport was inhibited by membrane impermeable protein modifying agents such as N-ethlymaleamide (NEM) and Pronase when added to intact ER vesicles. These results suggest that the transport is mediated by a protein with an active cytoplasmic face. Using monoclonal and polyclonal antibodies to BiP and Grp94 (another resident ER protein) and U.V. crosslinking, we demonstrated that after transport of ATPα32P into intact vesicles, radiolabeled BiP and Grp94 could be immunoprecipitated. We also found that labeling of lumenal proteins with ATP is dependent on the transport of ATP. Finally using ATP labeled with 35S, we concluded that BiP was able to bind intact ATP and we confirmed earlier work that BiP was thiophosphorylated while Grp94 is not. The second area of study involves processes that occur further along the secretory pathway in the Golgi apparatus. It was known from previous work that the nucleotide sugar substrates necessary for the synthesis of the linkage region, UDP-xylose (UDP-Xyl), UDP-galactose (UDP-Gal) and UDP-glucuronic acid (UDP-GlcA) were transported into the Golgi apparatus from the cytosol via protein mediated transporters. In order to eventually purify one of these transporter proteins, we wanted to reconstitute their activities. We were able to reconstitute the activities that exhibited kinetic parameters and inhibitor sensitivities very similar to those seen in intact Golgi vesicles. In the case of UDP-xylose it was necessary to prepare the liposomes using endogenous Golgi lipids in order to get transport activity similar to that seen in the intact Golgi vesicles. This suggested a specific lipid requirement for the UDP-xylose transporter. These transporters seem to be antiporters, whereby the nucleotide sugar enters the lumen of the Golgi coupled to the equimolar exit of the corresponding nucleoside monophosphate (Hirschberg, C.B. and Snider, M.D. 1987). We also showed that we could reproduce the hypothesized antiporter system in the reconstituted proteoliposomes by preloading the proteoliposomes with the putative antiporter molecule UMP. The rationale for developing the reconstituted system is eventually to use this system to purify one of these nucleotide sugar translocators. In the last set of studies, I have shown that this reconstituted system can be used to monitor the purification of the UDP-galactose translocator. Using column chromatography we were able to purify this membrane translocator protein 45,000 fold from a rat liver homogenate

Decision Support Model to Optimize Site Characterization Activities Taken in Compliance with the Comprehensive Environmental Response Compensation and Liability Act

One of the most frequently cited reasons for the slow and costly progress of Superfund cleanups is the remedial investigation and feasibility study process (RI/FS). After each phase of the RI/FS process there are several possible alternatives that may be chosen. This research developed decision support models to help decision makers choose between the feasible alternatives at five different decision points during site characterization activities. The models make recommendations on how to deal with any particular chemical based on the risk posed by that chemical. The models assume that the value of characterizing the site further is a reduction in the uncertainty associated with the chemical concentrations in the contaminated media and a reduction in the probability of errors occurring during and after remedy selection. The models developed in this research were verified and validated using data from a fully characterized hazardous waste site. The site evaluated was the POL Storage Area in operable unit two at Wright-Patterson AEB, Ohio

The Structure, Function, and Regulation of Insulin-like Growth factor II/Mannose 6-phosphate Receptor Forms: a Thesis

In mammals a single receptor protein binds both insulin-like growth factor II (IGF-II) and mannose 6-phosphate (Man 6-P) containing ligands, most notably lysosomal enzymes. However, in chick embryo fibroblasts IGF-II binds predominantly to a type 1 IGF receptor, and no IGF-II/Man 6-P receptor has been identified in this species. In order to determine if chickens possess an IGF-II/Man 6-P receptor, an affinity resin (pentamannosyl 6-phosphate (PMP) Sepharose) was used to purify receptors from chicken membrane extracts by their ability to bind mannose 6-phosphate. Then 125I-IGF-II was used to evaluate their ability to bind IGF-II. These experiments demonstrate that nonmammalian Man 6-P receptors lack the ability to bind IGF-II, suggesting that the ability to bind IGF-II has been gained recently in evolution by the mammalian Man 6-P receptor. The second area of study involves the serum form of the IGF-II/Man 6-P receptor. This receptor had been detected in the serum of a number of mammalian species, yet its structure, function, regulation, and origin were unknown. Initial studies, done with Dr. R. G. MacDonald, showed that the serum receptor is truncated such that the C-terminal cytoplasmic domain of the cellular receptor is removed. These studies also demonstrate a regulation of serum receptor levels with age, similar to that seen for the cellular receptor, and that the serum form of the receptor existed in several forms which appeared intact under nonreducing conditions, but as multiple proteolytic products upon reduction. Finally, these studies demonstrated that both the cellular and serum IGF-II/Man 6-P receptors are capable of binding IGF-II and Man 6-P simultaneously. In studies on the serum form of the IGF-II/Man 6-P receptor that I have conducted independently, the regulation of the serum IGF-II/Man 6-P and transferrin receptors by insulin has been demonstrated. In these studies, insulin injected into rats subcutaneously resulted in a time and dose dependent increase in serum receptor levels. Finally, to investigate the relationship of the serum IGF- II/Man 6-P receptor to the cellular form of the receptor, pulse chase experiments were performed. These experiments demonstrate that the soluble (serum form released into the medium) receptor is a major degradation product of the cellular receptor. Furthermore, the lack of detectable amounts of the lower Mr soluble receptor intracellularly and the parallel relationship of cell surface and soluble receptor suggest that the proteolysis is occurring from the cell surface. Finally, a number of experiments suggest that the degradation rate depends upon the conformation state of the receptor: binding of IGF-II or Man 6-P makes the receptor more susceptible to proteolysis while the presence of lysosomal enzymes prevents receptor proteolysis. In summary, the serum form of the IGF-II receptor is a proteolytic product of the cellular form of the receptor. The rate of release depends upon the number of receptors at the cell surface and the binding state of the receptor. In circulation, the receptor retains the ability to bind both types of ligands, it thus may serve as an IGF binding protein and/or a lysosomal enzyme binding protein. These results suggest a model whereby the cellular receptor is proteolytically cleaved by a plasma membrane protease to produce a short membrane anchored fragment and the serum receptor. In vivo this pathway serves as the major degradative pathway of the IGF-II/Man 6-P receptor, with the serum form being cleared from circulation by further degradation and reuptake

Evidence for a posttranscriptional effect of retinoic acid on connexin43 gene expression via the 3′-untranslated region

AbstractAll-trans retinoic acid (10−7 M) induces cell–cell communication and the expression of the gap junction protein connexin43 in mouse F9 teratocarcinoma cells. Previous experiments revealed an increase of mRNA but no change in the transcription of connexin43, suggesting a posttranscriptional mechanism responsible for the regulation of connexin43 gene expression. In transient transfection experiments using an expression vector containing the 3′-untranslated region of the connexin43 gene downstream of the luciferase coding sequence driven by the connexin43 promoter we show here that retinoic acid enhances luciferase activity via the connexin43 3′-untranslated region due to altered stability of the mRNA. Thus, retinoic acid is able to influence connexin43 gene expression at the level of mRNA stability via elements located in the 3′-untranslated region

Getting Past the Gatekeepers: The Reception of Restorative Justice inthe Nova Scotian Criminal Justice System

This paper draws upon twelve years of multi-dimensional research and focuses on the reception of restorative justice in the criminal justice system in Nova Scotia. The paper traces the evolution of the restorative justice social movement, examining the launching and take-off phases, the impact on the police gatekeeping role, the receptivity and use of restorative justice by other criminal justice system professionals, its current level of institutionalization in the criminal justice system, and its future prospects