Regional growth, structural change, and natural disaster

Hurricanes, earthquakes, floods, and other serious natural hazards have been attributed with causing changes in regional economic growth, income, employment, and wealth. Natural disasters are said to cause; (1) an acceleration of existing economic trends; (2) an expansion of employment and income, due to recovery operations (the so-called silver lining); and (3) an alteration in the structure of regional economic activity due to changes in "intra" and "inter" regional trading patterns, and technological change.^ Theoretical and stylized disaster simulations (Cochrane 1975; Haas, Cochrane, and Kates 1977; Petak et al. 1982; Ellson et al. 1983, 1984; Boisvert 1992; Brookshire and McKee 1992) point towards a wide scope of possible negative and long lasting impacts upon economic activity and structure. This work examines the consequences of Hurricane Andrew on Dade County's economy. Following the work of Ellson et al. (1984), Guimaraes et al. (1993), and West and Lenze (1993; 1994), a regional econometric forecasting model (DCEFM) using a framework of "with" and "without" the hurricane is constructed and utilized to assess Hurricane Andrew's impact on the structure and level of economic activity in Dade County, Florida.^ The results of the simulation exercises show that the direct economic impact associated with Hurricane Andrew on Dade County is of short duration, and of isolated sectoral impact, with impact generally limited to construction, TCP (transportation, communications, and public utilities), and agricultural sectors. Regional growth, and changes in income and employment reacted directly to, and within the range and direction set by national economic activity. The simulations also lead to the conclusion that areal extent, infrastructure, and sector specific damages or impacts, as opposed to monetary losses, are the primary determinants of a disaster's effects upon employment, income, growth, and economic structure. ^

Structural adjustment and labor in Jamaica and the Dominican Republic

Statement of the problem. It seeks to examine whether structural adjustment in Jamaica produced the desired developmental effects for labor--both organized and non-unionized--and if there is any significant difference in the Dominican Republic, which did not undergo that economic transformation. The research hypothesis is; "Structural Adjustment leads to Marginalization of labor."^ Methodology used. The methodology is mostly a straight cross-sectional analysis using data sets and publications from the UN, ILO, World Bank and IDB, as well as local statistical sources. The dissertation is primarily an historical to contemporary analysis of the Jamaican experience under structural adjustment, as it related to labor. To a greater extent it involves a straight cross-national comparison on the historical experiences of each country and a discussion of the relative similarities and differences between them, and the impact these features had on labor.^ Summary of findings. In the end, the question is asked as to whether internal factors are important in the relative success or failure of development strategies. From the data there is some indication that under structural adjustment there has been limited economic benefits for labor in Jamaica while labor standards have not improved. In the Dominican Republic the economic performance has been similar but the labor standards have improved significantly. This thus leads to the conclusion that structural adjustment may have been a factor in the resistance to labor's empowerment.^ Nevertheless, the study also shows that there may have been a causal role which local power relations had. The suggestion from the study is that in analyzing the phenomenon, attention must be paid to internal as well as external dynamics and variables. ^

Specificity, stability and comparative physiology of coral-Symbiodinium mutualisms: Evaluating the potential for acclimation and/or adaptation in reef corals

The relationship between reef corals and endosymbiotic dinoflagellates is fundamental to the existence of coral reefs. To evaluate the fidelity of coral-Symbiodinium mutualisms, corals maintained in aquaria for years were analyzed by denaturant gradient gel electrophoresis (DGGE). Comparing Symbiodinium populations of captive aquarium colonies with known associations in nature is a practical way of examining partner flexibility. The finding of "normal" symbiont populations in corals existing under highly variable conditions supports the premise that most coral colonies possess stable associations. High sensitivity real-time PCR (rtPCR) was used to evaluate background populations of the putatively stress-tolerant Symbiodinium D in reef corals of the Caribbean. Analyses of samples collected during periods of environmental stability indicate the ability of Symbiodinium D to associate with a wider diversity of host taxa than previously recognized. To gain a broader perspective with regard to the ecology of Symbiodinium D1a, rtPCR and DGGE were used to evaluate the symbiont populations of reef corals from Barbados before and after the 2005 mass coral bleaching. Background populations were observed in 56% of the host genera prior to observations of bleaching. These findings indicate that 'stress', not 'bleaching', caused the displacement of 'natural' symbiont population and the opportunistic proliferation of D1a in many host taxa. Of the 12 host taxa monitored before and after the bleaching event, there was a 40% increase in colonies hosting Symbiodinium D1a. Together, these studies elucidate the mechanism responsible for recent observations reporting the emergence of Symbiodinium D following thermal disturbances. These observations are now most easily explained as the disproportionate growth of existing in hospite symbiont populations, rather than novel symbiont acquisition subsequent to bleaching. To evaluate the comparative "fitness" of corals able to host multiple symbiont types, rates of calcification were measured in P. verrucosa hosting either Symbiodinium C1b-c or D1 at elevated temperature. Rates of calcification decreased significantly for both host-symbiont combinations, but differences attributable to symbiont composition were not detected. This research improves our knowledge of the symbiosis biology and ecology of reef corals and contributes information necessary to most accurately predict the response of these ecosystems to global climate changes.

Does core strength training influence kinetic efficiency, lower extremity stability, and 5000m performance in runners?

Context: Core strength training (CST) has been popular in the fitness industry for a decade. Although strong core muscles are believed to enhance athletic performance, only few scientific studies have been conducted to identify the effectiveness of CST on improving athletic performance. Objective: Identify the effects of a 6-wk CST on running kinetics, lower extremity stability, and running performance in recreational and competitive runners. Design and Setting: A test-retest, randomized control design was used to assess the effect of CST and no CST on ground reaction force (GRF), lower extremity stability scores, and running performance. Participants: Twenty-eight healthy adults (age, 36.9+9.4yrs, height, 168.4+9.6cm, mass, 70.1+15.3kg) were recruited and randomly divided into two groups. Main outcome Measures: GRF was determined by calculating peak impact vertical GRF (vGRF), peak active vGRF, duration of the breaking or horizontal GRF (hGRF), and duration of the propulsive hGRF as measured while running across a force plate. Lower extremity stability in three directions (anterior, posterior, lateral) was assessed using the Star Excursion Balance Test (SEBT). Running performance was determined by 5000 meter run measured on selected outdoor tracks. Six 2 (time) X 2 (condition) mixed-design ANOVA were used to determine if CST influences on each dependent variable, p < .05. Results: No significant interactions were found for any kinetic variables and SEBT score, p>.05. But 5000m run time showed significant interaction, p < .05. SEBT scores improved in both groups, but more in the experimental group. Conclusion: CST did not significantly influence kinetic efficiency and lower extremity stability, but did influence running performance.

Pressure induced structural changes and gas diffusion pathways in monomeric fluorescent proteins

Fluorescent proteins (FPs) are extremely valuable biochemical markers which have found a wide range of applications in cellular and molecular biology research. The monomeric variants of red fluorescent proteins (RFPs), known as mFruits, have been especially valuable for in vivo applications in mammalian cell imaging. Fluorescent proteins consist of a chromophore caged in the beta-barrel protein scaffold. The photophysical properties of an FP is determined by its chromophore structure and its interactions with the protein barrel. Application of hydrostatic pressure on FPs results in the modification of the chromophore environment which allows a systematic study of the role of the protein-chromophore interactions on photophysical properties of FPs. Using Molecular Dynamics (MD) computer simulations, I investigated the pressure induced structural changes in the monomeric variants mCherry, mStrawberry, and Citrine. The results explain the molecular basis for experimentally observed pressure responses among FP variants. It is found that the barrel flexibility, hydrogen bonding interactions and chromophore planarity of the FPs can be correlated to their contrasting photophysical properties at vaious pressures. I also investigated the oxygen diffusion pathways in mOrange and mOrange2 which exhibit marked differences in oxygen sensitivities as well as photostability. Such computational identifications of structural changes and oxygen diffusion pathways are important in guiding mutagenesis efforts to design fluorescent proteins with improved photophysical properties.

Structural flexibility and oxygen diffusion pathways in monomeric fluorescent proteins

Fluorescent proteins are valuable tools as biochemical markers for studying cellular processes. Red fluorescent proteins (RFPs) are highly desirable for in vivo applications because they absorb and emit light in the red region of the spectrum where cellular autofluorescence is low. The naturally occurring fluorescent proteins with emission peaks in this region of the spectrum occur in dimeric or tetrameric forms. The development of mutant monomeric variants of RFPs has resulted in several novel FPs known as mFruits. Though oxygen is required for maturation of the chromophore, it is known that photobleaching of FPs is oxygen sensitive, and oxygen-free conditions result in improved photostabilities. Therefore, understanding oxygen diffusion pathways in FPs is important for both photostabilites and maturation of the chromophores. We used molecular dynamics calculations to investigate the protein barrel fluctuations in mCherry, which is one of the most useful monomeric mFruit variants, and its GFP homolog citrine. We employed implicit ligand sampling and locally enhanced sampling to determine oxygen pathways from the bulk solvent into the mCherry chromophore in the interior of the protein. The pathway contains several oxygen hosting pockets, which were identified by the amino acid residues that form the pocket. We calculated the free-energy of an oxygen molecule at points along the path. We also investigated an RFP variant known to be significantly less photostable than mCherry and find much easier oxygen access in this variant. We showed that oxygen pathways can be blocked or altered, and barrel fluctuations can be reduced by strategic amino acid substitutions. The results provide a better understanding of the mechanism of molecular oxygen access into the fully folded mCherry protein barrel and provide insight into the photobleaching process in these proteins.

Pressure Induced Structural Changes and Gas Diffusion Pathways in Monomeric Fluorescent Proteins

Fluorescent proteins (FPs) are extremely valuable biochemical markers which have found a wide range of applications in cellular and molecular biology research. The monomeric variants of red fluorescent proteins (RFPs), known as mFruits, have been especially valuable for in vivo applications in mammalian cell imaging. Fluorescent proteins consist of a chromophore caged in the beta-barrel protein scaffold. The photophysical properties of an FP is determined by its chromophore structure and its interactions with the protein barrel. Application of hydrostatic pressure on FPs results in the modification of the chromophore environment which allows a systematic study of the role of the protein-chromophore interactions on photophysical properties of FPs. Using Molecular Dynamics (MD) computer simulations, I investigated the pressure induced structural changes in the monomeric variants mCherry, mStrawberry, and Citrine. The results explain the molecular basis for experimentally observed pressure responses among FP variants. It is found that the barrel flexibility, hydrogen bonding interactions and chromophore planarity of the FPs can be correlated to their contrasting photophysical properties at vaious pressures. I also investigated the oxygen diffusion pathways in mOrange and mOrange2 which exhibit marked differences in oxygen sensitivities as well as photostability. Such computational identifications of structural changes and oxygen diffusion pathways are important in guiding mutagenesis efforts to design fluorescent proteins with improved photophysical properties.