Population Changes of North Dakota\u27s Rural Trade Centers, 1960-1970

Research in trade relationships and hinterland analysis has shown that rural trade centers do not exist in isolation, but exhibit an interdependence with other rural and urban places. The purpose of this study is to examine relationships among trade centers by measuring their potential for growth. The construct selected for growth analysis examines rural trade center population changes in relation to the size of rural trade centers, distance from urban centers, and the size of neighboring trade centers, both urban and rural. Trade centers having populations greater than 2,500 in 1970, were defined as urban. All trade centers considered were located within the politically defined boundaries of the State of North Dakota. Detailed examinations of rural trade center relationships were made with respect to urban centers, and regional urban centers. The Fargo-Moorhead urbanized area located in Cass County was used as a case study. Urban centers were differentiated by size—2,500 to 5,000 (Category I) and 5,000 and over (Category II). Regional center population size was 10,000 and over. Population change of rural trade centers was selected as a measurement indicator. A positive population change from 1960 to 1970 was assumed to be indicative of a potential for future population growth and a symbiotic relationship. A negative population change was assumed to be indicative of a lack of growth potential and a competitive relationship. The hypothesis selected for testing assumed rural trade centers to be at a disadvantage when located within 20 miles of urban centers. Underlying this assumption is the postulate that rural trade centers are integrated elements of a hierarchial system and function in association with urban centers. The methodology utilized tabular analysis to identify the relationships and correlation coefficients to measure the degree of association. Results of the tabular and statistical analyses were supplemented with field observations concerning the factors related to population change. The results indicated weak associations between population change and distance to urban centers. It was found that Category I urban centers compete with rural trade centers. Also, a stronger association exists between growth of rural centers and distance to Category II and regional urban centers. Symbiotic relationships are most strongly developed in Cass County, however, growth patterns cannot be fully explained by the relationship between rural trade centers and the City of Fargo. The correlation between rural trade center population change and distance to other rural trade centers was positive. Lack of statistical significance, however, prevented statistical verification of a competitive relationship. The correlation between size of rural trade center and population change was .18 and significant. In comparison to correlations between population change and distance to urban centers, this indicated that size of a rural trade center is a more important variable associated with growth in an area where relationships between urban and rural trade centers are weakly developed

Modulators of Cytoskeletal Reorganization in CA1 Hippocampal Neurons Show Increased Expression in Patients at Mid-Stage Alzheimer's Disease

During the progression of Alzheimer's disease (AD), hippocampal neurons undergo cytoskeletal reorganization, resulting in degenerative as well as regenerative changes. As neurofibrillary tangles form and dystrophic neurites appear, sprouting neuronal processes with growth cones emerge. Actin and tubulin are indispensable for normal neurite development and regenerative responses to injury and neurodegenerative stimuli. We have previously shown that actin capping protein beta2 subunit, Capzb2, binds tubulin and, in the presence of tau, affects microtubule polymerization necessary for neurite outgrowth and normal growth cone morphology. Accordingly, Capzb2 silencing in hippocampal neurons resulted in short, dystrophic neurites, seen in neurodegenerative diseases including AD. Here we demonstrate the statistically significant increase in the Capzb2 expression in the postmortem hippocampi in persons at mid-stage, Braak and Braak stage (BB) III-IV, non-familial AD in comparison to controls. The dynamics of Capzb2 expression in progressive AD stages cannot be attributed to reactive astrocytosis. Moreover, the increased expression of Capzb2 mRNA in CA1 pyramidal neurons in AD BB III-IV is accompanied by an increased mRNA expression of brain derived neurotrophic factor (BDNF) receptor tyrosine kinase B (TrkB), mediator of synaptic plasticity in hippocampal neurons. Thus, the up-regulation of Capzb2 and TrkB may reflect cytoskeletal reorganization and/or regenerative response occurring in hippocampal CA1 neurons at a specific stage of AD progression