At What Cost?: A Study of the American Highway System and the Maine East-West Highway Proposal

Highway construction has been a staple of American development since the early twentieth century, drastically changing the American landscape. The United States is a nation characterized by, and dependent upon automobile transportation as constructed by this vast network of asphalt connectors, symbolizing a “high-modernist” ideology and state control. Despite our obvious needs for road and highway construction, we must tread lightly. As America’s continued quest for increased connectivity and infrastructure grows, there must also be a balanced and fair look at both the benefits and costs related to highway construction. Political, sociological, economic and environmental concerns must be considered, and this is demonstrated by this thesis through case studies, in particular the analysis of a proposed East-West Highway in Maine. Ultimately, discussion of any extensive new highway construction must begin with inclusive discussion. Before any sizable public works project is undertaken, our analysis and examination should always consider political, sociological, economic and environmental questions and issues. Communities must decide whether the benefits of highway construction outweigh the costs and whether those costs are risks worth taking

Molecular Mechanisms Underlying Synaptic Connectivity in C. elegans

Proper synaptic connectivity is critical for communication between cells and information processing in the brain. Neurons are highly interconnected, forming synapses with multiple partners, and these connections are often refined during the course of development. While decades of research have elucidated many molecular players that regulate these processes, understanding their specific roles can be difficult due to the large number of synapses and complex circuitry in the brain. In this thesis, I investigate mechanisms that establish neural circuits in the simple organism C. elegans, allowing us to address this important problem with single cell resolution in vivo. First, I investigate remodeling of excitatory synapses during development. I show that the immunoglobulin domain protein OIG-1 alters the timing of remodeling, demonstrating that OIG-1 stabilizes synapses in early development but is less critical for the formation of mature synapses. Second, I explore how presynaptic excitatory neurons instruct inhibitory synaptic connectivity. My work shows that disruption of cholinergic neurons alters the pattern of connectivity in partnering GABAergic neurons, and defines a time window during development in which cholinergic signaling appears critical. Lastly, I define novel postsynaptic specializations in GABAergic neurons that bear striking similarity to dendritic spines, and show that presynaptic nrx-1/neurexin is required for the development of spiny synapses. In contrast, cholinergic connectivity with their other postsynaptic partners, muscle cells, does not require nrx-1/neurexin. Thus, distinct molecular signals govern connectivity with these two cell types. Altogether, my findings identify fundamental principles governing synapse development in both the developing and mature nervous system

The role of Wolframin in the pathogenesis of Wolfram or Didmoad syndrome

The Wolfram Syndrome (WS) is an autosomal recessive neurodegenerative disorder characterised by insulin-dependent diabetes mellitus (IDDM) and bilateral progressive optic atrophy. Manifestations in neural and neuroendocrine tissues generally arise, but are not a requirement for diagnosis. A novel gene was identified in 1998 on chromosome 4p16.1 (WFS1 or Wolframin) that contains loss-of-function mutations in a majority of Wolfram patients. This gene encode for a putative hydrophobic transmembrane protein of 890aa and its predicted molecular weight is 100.29 kDa based on the amino acid sequence. This thesis was intended to study the localisation and function of this gene product in order to gain insight into its role in the pathogenesis of diabetes mellitus and neurodegeneration. In order to study the role of the Wolframin gene in diabetes, its mRNA expression was analysed during the development of diabetes in the Nonobese Diabetic (NOD) mouse model. This showed a decrease in Wolframin expression in the pancreas of NOD mice 9 days after induction for diabetes, indicating a possible involvement of Wolframin in the survival of β-cells. Fibroblast cells and blood samples from Wolfram patients were obtained and analysed for their mutations. One patient was compound heterozygotic for two separate mutations and one patient was homozygotic for a single insertion leading to an early stop codon. RT-PCR of these cells showed no significant difference in mRNA expression as compared to either fibroblasts from first-grade relatives or control cells. These cells were used in various functional assays. First of all, microarray analysis was used to identify genes that are affected when the Wolframin gene is non-functional. These results lead to the investigation of the role of Wolframin in senescence using markers of growth rate and radiation. No difference was found between fibroblasts from a Wolfram patient and her sibling, not supporting a role for Wolframin in senescence. Since the mouse homologue is 83% identical to the human variant on an amino acid level it is likely that there is also functional homology. Therefore, in order to study the pathomechanisms acting in human disease, a knock-out mouse construct was produced thus overcome the limitation to obtain human material. Two constructs were electroporated into embryonic stem cells and so far a total of 1080 colonies were screened, however, no positive clones were obtained. In order to investigate this gene on a protein level, antibodies were raised against the N- and C- terminus. The respective protein was found to be expressed in many tissues and cell lines with the highest expression in brain, pancreas, heart and insulinoma β-cell lines. Using sub-cellular fractionation techniques, the protein was found exclusively in microsomal fractions. Immunofluorescence on transfected cos-7 cells showed intracellular localisation to the endoplasmic reticulum. Incubating mouse pancreas slices with the Wolframin antibody showed exclusive staining in the β-cells and co-localisation to insulin. Immunofluorescence analysis also showed immunoreactivity to structures of the limbic system in the mouse brain. These results give the first clues towards a possible function in processing or trafficking of proteins involved in the survival of neuronal and endocrine cells

Highlights of Life on Matinicus Island

https://digitalmaine.com/books/1136/thumbnail.jp

Eric P. Kelly Correspondence

Entries include letters and a biographical newspaper clipping