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Title
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ZIKA VIRUS-INDUCED PREGNANCY LOSS : LESSONS FROM THE MOUSE EMBRYO
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Creator
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Watts, Jennifer Leticia
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Date
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2021
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Collection
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Electronic Theses & Dissertations
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Description
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Adults contracting Zika virus (ZIKV) exhibit mild cold-like symptoms, whereas newborn babiesexhibit fetal defects ranging from mild growth retardation to miscarriage. Aside from transmission via mosquito, ZIKV is also sexually transmitted, which introduces the possibility that ZIKV infection could occur shortly after conception. However, the mechanisms underlying ZIKV-induced birth defects in early development are not understood. I hypothesize that sexually transmitted ZIKA virus infects...
Show moreAdults contracting Zika virus (ZIKV) exhibit mild cold-like symptoms, whereas newborn babiesexhibit fetal defects ranging from mild growth retardation to miscarriage. Aside from transmission via mosquito, ZIKV is also sexually transmitted, which introduces the possibility that ZIKV infection could occur shortly after conception. However, the mechanisms underlying ZIKV-induced birth defects in early development are not understood. I hypothesize that sexually transmitted ZIKA virus infects embryos around the time of conception, leading to the most severe congenital defects. Consistent with this hypothesis, I have discovered that candidate proviral factors are present in mouse embryo-derived stem cell lines and preimplantation development. However, embryo-derived stem cell lines exhibited low viral infection and replication. Nevertheless, Puerto Rican (ZIKVPR) and the Ugandan (ZIKVUG) strains of ZIKV caused two-cell embryos to undergo developmental arrest. Moreover, infected blastocyst exhibited reduced SOX2 expression, an epiblast cell marker, CDX2 a trophectoderm cell marker, and SOX17, a primitive endoderm marker. Therefore, my results suggest that preimplantation ZIKV infection causes embryonic demise or embryonic cell fate defects depending on the time of infection. My studies are significant to human health because they will further our knowledge of viral infection in early pregnancy and the outcomes.
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Title
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Ytterbium based alloys for space-based thermoelectric cooling applications
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Creator
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Lehr, Gloria Jeannine
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Date
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2014
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Collection
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Electronic Theses & Dissertations
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Description
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Solid-state thermoelectric devices are of great interest for researchers in many fields due to their potential to increase the efficiency of electrical power generation as well as provide localized heating or cooling in inconvenient environments. Improving the thermoelectric properties of the materials used in these devices is critical to improve their efficiencies and thus feasibility for niche applications. Unfortunately, several of the underlying materials properties are inversely...
Show moreSolid-state thermoelectric devices are of great interest for researchers in many fields due to their potential to increase the efficiency of electrical power generation as well as provide localized heating or cooling in inconvenient environments. Improving the thermoelectric properties of the materials used in these devices is critical to improve their efficiencies and thus feasibility for niche applications. Unfortunately, several of the underlying materials properties are inversely correlated making the thermoelectric figure of merit difficult to improve. In addition, the performance of traditional semiconducting materials is degraded as the operating temperature is decreased. Thus, a unique approach must be taken to achieve larger thermoelectric figures of merit at low temperatures. The research presented here investigates the use of intermediate valence Yb-based compounds for Peltier cooling in the cryogenic regime. These Yb-based intermediate valence compounds demonstrate large Seebeck coefficients at low temperatures, which is essential to a large figure of merit. The Seebeck coefficient is related to the fluctuating Yb valence, a relationship that is investigated in several compounds and utilized to maximize the thermoelectric figure of merit. Solid solutions are synthesized in order to reduce the lattice thermal conductivity as well as alter the size of the unit cell. Changes in the unit cell volume may contribute to a change in the average Yb valence, and thus be utilized to tune the magnitude and peak temperature of the Seebeck coefficient. By reducing the lattice thermal conductivity and optimizing the Seebeck coefficient, enhancements in the thermoelectric figure of merit can be achieved.
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Title
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Youth level of service/case management inventory : the predictive validity of post-court involvement assessment
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Creator
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Barnes, Ashlee R.
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Date
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2013
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Collection
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Electronic Theses & Dissertations
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Description
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Juvenile risk assessments are becoming increasingly popular in jurisdictions across North America. Court officials use risk assessment scales to predict future crime, identify youth needs, and inform case planning. If risk assessment tools are to be useful, they must demonstrate predictive validity overall as well as demonstrate predictive validity across gender and racial subgroups. Currently, the literature shows that juveniles are typically assessed when they enter court jurisdiction. This...
Show moreJuvenile risk assessments are becoming increasingly popular in jurisdictions across North America. Court officials use risk assessment scales to predict future crime, identify youth needs, and inform case planning. If risk assessment tools are to be useful, they must demonstrate predictive validity overall as well as demonstrate predictive validity across gender and racial subgroups. Currently, the literature shows that juveniles are typically assessed when they enter court jurisdiction. This initial risk assessment score is the only one used to predict recidivism. This study sought to determine the predictive accuracy of the composite risk score youth received following dismissal from court jurisdiction. The entry/initial and exit/dismissal composite scores were compared to identify their relative validity. Differential predictive validity across race/ethnicity and gender was also explored. Theoretical and policy implications and the impact of court supervision were then discussed.
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