The Impacts of Negative Interest Rates on the Eurozone Economy

This thesis evaluates the effects of a monetary policy shock in the Eurozone. The investigation stems from the recent implementation of negative interest rates in select European countries and Japan. Impulse response functions are used to compare variable responses when not influenced by negative rates versus when significantly impacted by this monetary policy. The inconclusiveness in the comparison between these two models resulted in failing to reject the hypothesis that negative interest rates have yet to be successful in the Eurozone. However, any economy is a complicated environment that cannot be modelled precisely, as numerous other factors play a role in the movements of macroeconomic variables. Therefore, this research is simply one possible perspective regarding this monetary policy

Identification of TMIGD1, a novel cell adhesion molecule involved in human trophoblast cell migration

Transmembrane and immunoglobulin domain-containing 1 (TMIGD1) is a newly identified cell adhesion molecule that mediates cell-cell interactions and is mainly expressed in kidney and colon epithelial cells. In renal epithelial cells, TMIGD1 regulates cell proliferation and migration. Human tissue panels showed expression of TMIGD1 in placenta; however, the potential function of TMIGD1 in placenta is not known. We elected to study the expression and function of TMIGD1 during placentation. This is of interest because dysregulation of placental invasion is linked to obstetrical complications such as preeclampsia and intrauterine growth restriction (IUGR). We hypothesized that TMIGD1 is expressed in trophoblast cells and regulates cell migration during placental invasion. Placental tissues were subjected to immunofluorescence (IF) staining using anti-TMIGD1 antibody and TMIGD1 localization in trophoblast was visualized using a fluorescence microscope. Additionally, we overexpressed TMIGD1 in the immortalized trophoblast cell line, HTR8/SVneo, via a retroviral system. Transduction was verified using IF, Western blot, and qPCR to compare the modified and original cell lines. Migration of TMIGD1-overexpressing HTR8/SVneo cells was assessed using wound-healing and transwell migration assays. We observed TMIGD1 localization in the apical region of syncytiotrophoblasts. TMIGD1 mRNA expression in the transduced HTR8/SVneo cells was 3-fold greater than that in the control line, and 400-fold greater in first trimester whole placenta. TMIGD1-overexpressing HTR8/SVneo cells exhibited a 30±5% decrease in migration in the wound-healing assay, compared to the untransduced cells. Similarly, TMIGD1 overexpression in HTR8/SVneo suppressed migration by 36%, compared to control cells in transwell assays. Fluorescent staining showed that increased TMIGD1 expression modifies actin cytoskeleton by redistributing filaments to the peripheries. Additionally, cells overexpressing TMIGD1 exhibit a distinct morphology that lacks filopodia or other motility structures. Our study demonstrates for the first time that TMIGD1 is expressed in trophoblast cells and acts to inhibit cell migration. The evidence presented in this study supports the idea that TMIGD1 expression in trophoblast may play an important function in regulating placental invasion, and that perturbations in its activity may be associated with obstetrical complications such as preeclampsia and intrauterine growth restriction

Three-dimensional tissue scaffolds from interbonded poly(e-caprolactone) fibrous matrices with controlled porosity

In this article, we report on the preparation and cell culture performance of a novel fibrous matrix that has an interbonded fiber architecture, excellent pore interconnectivity, and controlled pore size and porosity. The fibrous matrices were prepared by combining melt-bonding of short synthetic fibers with a template leaching technique. The microcomputed tomography and scanning electron microscopy imaging verified that the fibers in the matrix were highly bonded, forming unique isotropic pore architectures. The average pore size and porosity of the fibrous matrices were controlled by the fiber/template ratio. The matrices having the average pore size of 120, 207, 813, and 994 mm, with the respective porosity of 73%, 88%, 96%, and 97%, were investigated. The applicability of the matrix as a three-dimensional (3D) tissue scaffold for cell culture was demonstrated with two cell lines, rat skin fibroblast and Chinese hamster ovary, and the influences of the matrix porosity and surface area on the cell culture performance were examined. Both cell lines grew successfully in the matrices, but they showed different preferences in pore size and porosity. Compared with two-dimensional tissue culture plates, the cell number on 3D fibrous matrices was increased by 97.27% for the Chinese hamster ovary cells and 49.46% for the fibroblasts after 21 days of culture. The fibroblasts in the matrices not only grew along the fiber surface but also bridged among the fibers, which was much different from those on two-dimensional scaffolds. Such an interbonded fibrous matrix may be useful for developing new fiber-based 3D tissue scaffolds for various cell culture applications

Metabolic Impacts of Using Nitrogen and Copper-Regulated Promoters to Regulate Gene Expression in Neurospora crassa.

The filamentous fungus Neurospora crassa is a long-studied eukaryotic microbial system amenable to heterologous expression of native and foreign proteins. However, relatively few highly tunable promoters have been developed for this species. In this study, we compare the tcu-1 and nit-6 promoters for controlled expression of a GFP reporter gene in N. crassa. Although the copper-regulated tcu-1 has been previously characterized, this is the first investigation exploring nitrogen-controlled nit-6 for expression of heterologous genes in N. crassa. We determined that fragments corresponding to 1.5-kb fragments upstream of the tcu-1 and nit-6 open reading frames are needed for optimal repression and expression of GFP mRNA and protein. nit-6 was repressed using concentrations of glutamine from 2 to 20 mM and induced in medium containing 0.5-20 mM nitrate as the nitrogen source. Highest levels of expression were achieved within 3 hr of induction for each promoter and GFP mRNA could not be detected within 1 hr after transfer to repressing conditions using the nit-6 promoter. We also performed metabolic profiling experiments using proton NMR to identify changes in metabolite levels under inducing and repressing conditions for each promoter. The results demonstrate that conditions used to regulate tcu-1 do not significantly change the primary metabolome and that the differences between inducing and repressing conditions for nit-6 can be accounted for by growth under nitrate or glutamine as a nitrogen source. Our findings demonstrate that nit-6 is a tunable promoter that joins tcu-1 as a choice for regulation of gene expression in N. crassa