The role of cyclic nucleotides in modulation of crayfish neuromuscular junctions by a neuropeptide /

DF2, a heptapeptide, is a member of the family of FMRFamide-like peptides and has been shown to increase the amount of transmitter released at neuromuscular junctions of the crayfish, Procambarus clarkit Recent evidence has shown that protein kinase C (PKC), calcium/calmodulin-dependent protein kinase II (CaMKII) and the cAMPdependent protein kinase (PKA) play a role in the neuromodulatory pathway of DF2. The involvement of these kinases led to the prediction that a G-protein-coupled receptor (GPCR) is activated by DF2 due to the role that each kinase plays in traditional GPCR pathways seen in other organisms and in other cells. G-proteins can also act on an enzyme that generates cyclic guanosine monophosphate (cGMP) which mediates its effects through a cGMP-dependent protein kinase (PKG). This thesis addresses the question of whether or not DF2's effects on synaptic transmission in crayfish are mediated by the cyclic nucleotides cAMP and cGMP. The effects of DF2 on synaptic transmission were examined using deep abdominal extensor muscles of the crayfish Procambarus clarkii. An identified motor neuron was stimulated, and excitatory post-synaptic potentials (EPSPs) were recorded in abdominal extensor muscle LI . A number of activators and inhibitors were used to determine whether or not cAMP, PKA, cGMP and PKG mediate the effect of this peptide. Chemicals that are known to activate PKA (Sp-cAMPS) and/or PKG (8-pCPTcGMP) mimic and potentiate DF2's effect by increasing EPSP amplitude. Inhibitors of either PKA (Rp-cAMPS) or PKG (Rp-8-pCPT-cGMPS) block a portion of the increase in EPSP amplitude induced by the peptide. When both kinase inhibitors are applied simultaneously, the entire effect of DF2 on EPSPs is blocked. The PKG inhibitor blocks the effects of a PKG activator but does not alter the effect of a PKA activator on EPSP amplitude. Thus, the PKG inhibitor appears to be relatively specific for PKG. A trend in the data suggests that the PKA inhibitor blocks a portion of the response elicited by the PKG activator. Thus, the PKA inhibitor may be less specific for PKA. Phosphodiesterase inhibitors, which are known to inhibit the breakdown of cAMP (IBMX) and/or cGMP (mdBAMQ), potentiate the effect of the peptide. These results support the hypothesis that cAMP and cGMP, acting through their respective protein kinase enzymes, mediate the ability of DFi to increase transmitter output.

Synechococcus sp. PCC 7002 CpcB lyase null mutations alter phycocyanin chromophore function and, consequently, affect the redistribution of excitation energy via the light state transition /

Phycobilisomes are the major light harvesting complexes for cyanobacteria and phycocyanin is the primary phycobiliprotein of the phycobilisome rod. The phycocyanobilin lyases responsible for chromophorylating the phycocyanin p subunit (CpcB) have been recently identified in the cyanobacterium Synechococcus sp. PCC 7002. Surprisingly, mutants missing the CpcB lyases were nevertheless capable of producing pigmented phycocyanin. 10K absorbance measurements revealed that the energy states of the p phycocyanin chromophores were only subtly shifted; however, 77K steady state fluorescence emission spectroscopy showed excitation energy transfer involving the targeted chromophores to be highly disrupted. Such evidence suggests that phycobilin orientation within the binding domain is specifically modified. We hypothesized that alternate, less specific lyases are able to act on the p binding sites. A phycocyanin linker-polypeptide deficient mutant was similarly characterized. The light state transition, a short term adaptation of the photosynthetic light harvesting apparatus resulting in the redistribution of excitation energy among the photo systems, was shown to be dominated by the reallocation of phycocyanin-absorbed excitation energy. Treatment with a high M phosphate buffer effectively prevented the redistribution of both chlorophyll a- and phycobilisome- absorbed excitation energy, suggesting that the two effects are not strictly independent. The mutant strains required a larger redistribution of excitation energy between light states, perhaps to compensate for their loss in phycobilisome antenna function.

Climbers' perceptions toward sustainable bouldering at the Niagara Glen Nature Reserve

Currently, there are a variety of concerns about the future of bouldering, a form of rock climbing, a t the Niagara Glen Nature Reserve near Niagara Falls, Ontario due to environmental impacts at the site. The purpose of this study was to describe the perceptions ofbouldering participants toward sustainable bouldering practices at the Niagara Glen. The methodological framework for this study was based on action research, which attempts to solve specific problems through having people in a community study, discuss, and act on those problems. Five separate focus group interviews elicited data from nineteen men and seven women, while there were twenty one men and ten women observed through participant observations at the Niagara Glen. Analysis was conducted through coding processes where data were compared repeatedly and then organized into themes. From the open coding process, two main themes were identified and interpreted as 1) Barriers to Sustainable Bouldering at the Niagara Glen Nature Reserve, and 2) Environmental and Social Role and Responsibility ofBoulde r ing Participants at the Niagara Glen. The implications of the findings include a variety of recommendations for the bouldering community and the Niagara Parks Commission to consider for future collaborative planning. Some of these recommendations include more open communication between all stakeholders at the Glen, additional leadership from local climbing access coalitions and the Niagara Parks Commission, and greater implementation of minimum impact practices from the bouldering community. Additionally, these implications are discussed through a three-part framework based on a conceptual intersection of sense of place, community empowerment, and sustainable recreational use as a way to potentially unify the bouldering community's voice and vision toward sustainable practice.

A Needs Assessment: Language Instruction Stakeholders Engaging in Project Based Learning Outside the Classroom for Effective Strategic Problem Solving

Abstract A noted benefit of Project Based Learning (PBL) as a teaching strategy is how it engages the student and enhances learning outcomes as a result of working through challenges intended to depict dilemmas outside the classroom. PBL has seldom been applied outside the parameters of the classroom curriculum. The current needs assessment carried out in this research project examined current practices of language instruction and International Administrative Professionals of both the private and public Language Industry. Participants responded to survey questions on their current administrative practices, strategies, and program characteristics. The study investigated the usefulness of a handbook on the procedure of assisting administrative service teams in language instruction settings to an engaged approach to PBL for student service issues. The diverse opinions, beliefs, and ideas, along with institutional policy, can provide beneficial framework ideas for future tools.

Letter from the Secretary of War, transmitting documents containing the information required by the resolution of Mr. Wright, on the 22d inst. relative to the execution of the act fixing the military peace establishment. --

14th Congress, 1st session, 1815-1816. House. Document no. 33.

An Act to authorise the stock held by private parties in the Welland Canal to be purchased on behalf of the Province [Welland Canal Stock Bill], 1841

The bill is a proposal by the government to purchase Welland Canal stock held in private hands. The bill was read for the first time on Wednesday 4 August, 1841, and received second reading on 10th August, 1841. One hundred and fifty copies were printed of the bill. This example was addressed to Samuel Street at the Falls of Niagara, by William Hamilton Merritt, September 1841.

Letter from the Secretary of War, transmitting documents containing the information required by the resolution of Mr. Wright, on the 22d inst. relative to the execution of the act fixing the military peace establishment

14th Congress, 1st session, 1815-1816. House. Document no. 33. January 27, 1816. Read and referred to the Committee on Military Affairs.

Act for Laying a Duty on the Retailers of Spirits and Liquors

An act to charge duty to retailers of liquor and for licensing retailers of liquor. The document beings "At the Parliament begun and holden at Westminster, the Fourteenth Day of January, Anno Dom. 1734 in the Eighth Year of the Reign of our Sovereign Lord George the Second, by the Grace of God, of Great Britain, France, and Ireland, Kind, Defender of the Faith, And from thence continued by federal Prorogation to the Fifteenth Day of January, 1735. being the Second Session of this present Parliament."

The Canada Not For Profit Corporations Act: Perceived impact on the governance of federal sport organizations

This thesis examined the impact of the Canada Not-for-Profit Corporations Act (2009) on the governance of national sport organizations (NSO). The impact of the legislation was explored through the perceptions of NSO executive leaders and by analyzing the by-laws in effect before the legislation. The legislation was perceived to have the greatest impact on enhancing accountability, specifically affecting membership categories and director selection. The interview data showed that the legislation was necessary to enhance accountability in many NSOs. The Respondents also demonstrated that they understood the goals sought through the legislation. The data also showed that the boards of NSOs were already in alignment with the goals of the legislation. With respect to governance, the data indicated that NSOs rely almost exclusively on their regional sport associations as voting stakeholders. An emerging issue that came out of the results was the role of athletes in the governance of sport organizations.