Trace metals in Arctic fast ice

Thesis (M.S.) University of Alaska Fairbanks, 2017Trace metals in the marine environment are found in trace amounts, but are important tracers of oceanographic processes, and bioactive trace metals can impact ocean biogeochemistry through their nutrient or toxic influence of microbial populations. Sea ice is an intrinsic feature of the Arctic Ocean that likely plays a key role in the cycling of trace metals, given that this substrate can concentrate, alter, and transport these elements. Warming conditions in the Arctic have decreased sea ice cover over the past decades and the loss of sea ice threatens to drastically change the Arctic ecosystem, but the implications are not entirely understood. The scarcity of studies on Arctic sea ice entrained trace metals is due in part to the lack of commercially available sampling equipment capable of collecting sea ice without introducing contamination, and in part to the logistic and economic difficulties in accessing remote Arctic sea ice sites. Natural heterogeneity related to large sediment loads incorporated in uneven patches across Arctic fast ice poses a challenge when designing observational studies of trace metals in sea ice. The scope of this thesis is on the study of trace metals in Alaskan Beaufort Sea fast ice environment. The study includes snow, sea ice and seawater under the ice. Analysis of dissolved (Mn, Fe, Cu and Zn) and particulate (Al, Mn, Fe, Cu and Zn) phases was carried out from 50 ice cores collected with a trace metal clean ice corer developed at the University of Alaska Fairbanks. The results of this study indicated that the ice corer developed at UAF was able to collect uncontaminated samples. Highly variable and elevated concentrations of particulate (> 0.2 μm) trace elements were observed due to the notable variability in the amount of sediment incorporated within ice cores, but surprisingly dissolved (< 0.2 μm) metal concentrations were relatively low and consistent. The observed low dissolved metal concentrations, along with low bulk salinity and low percent leachable particulate trace metal fractions, suggest that desalination removed reactive metals from the ice matrix prior to sampling. Spatial variability of dissolved and particulate trace metals was statistically analyzed and indicated generally negligible variability on the meter scale, but significant variability on the kilometer scale, for both size classes. These results emphasize that future studies of trace metals in sea ice should include temporal and spatial considerations.Chapter 1: Introduction -- Chapter 2: Spatial variability of Al, Mn, Fe, Cu and Zn in Beaufort Sea fast ice -- Chapter 3: Conclusions

Bundles and Hotspots of Multiple Ecosystem Services for Optimized Land Management in Kentucky, United States

Ecosystem services are benefits that the natural environment provides to support human well-being. A thorough understanding and assessment of these services are critical to maintain ecosystem services flow through sustainable land management to optimize bundles of ecosystem services provision. Maximizing one particular ecosystem service may lead to reduction in another. Therefore, identifying ecosystem services tradeoffs and synergies is key in addressing this challenge. However, the identification of multiple ecosystem services tradeoffs and synergies is still limited. A previous study failed to effectively capture the spatial interaction among ecosystem services as it was limited by “space-to-time” substitution method used because of temporal data scarcity. The study was also limited by using land use types in creating ecosystem services, which could lead to some deviations. The broad objective of this study is therefore to examine the bundles and hotspots of multiple ecosystem services and their tradeoffs in Kentucky, U.S. The study combined geographic data and spatially-explicit models to identify multiple ecosystem services bundles and hotspots, and determined the spatial locations of ecosystem services hotspots. Results showed that the spatial interactions among ecosystem services were very high: of the 21 possible pairs of ecosystem services, 17 pairs were significantly correlated. The seven ecosystem services examined can be bundled into three groups, geographically clustered on the landscape. These results support the hypothesis that some groups of ecosystem services provision can present similar spatial patterns at a large mesoscale. Understanding the spatial interactions and bundles of the ecosystem services provides essential information for evidence-based sustainable land management

Spindle assembly checkpoint genes reveal distinct as well as overlapping expression that implicates MDF-2/Mad2 in postembryonic seam cell proliferation in Caenorhabditis elegans

Background: The spindle assembly checkpoint (SAC) delays anaphase onset by inhibiting the activity of theanaphase promoting complex/cyclosome (APC/C) until all of the kinetochores have properly attached to thespindle. The importance of SAC genes for genome stability is well established; however, the roles these genes play,during postembryonic development of a multicellular organism, remain largely unexplored.Results: We have used GFP fusions of 5’ upstream intergenic regulatory sequences to assay spatiotemporalexpression patterns of eight conserved genes implicated in the spindle assembly checkpoint function inCaenorhabditis elegans. We have shown that regulatory sequences for all of the SAC genes drive ubiquitous GFPexpression during early embryonic development. However, postembryonic spatial analysis revealed distinct, tissuespecificexpression of SAC genes with striking co-expression in seam cells, as well as in the gut. Additionally, weshow that the absence of MDF-2/Mad2 (one of the checkpoint genes) leads to aberrant number and alignment ofseam cell nuclei, defects mainly attributed to abnormal postembryonic cell proliferation. Furthermore, we showthat these defects are completely rescued by fzy-1(h1983)/CDC20, suggesting that regulation of the APC/CCDC20 bythe SAC component MDF-2 is important for proper postembryonic cell proliferation.Conclusion: Our results indicate that SAC genes display different tissue-specific expression patterns duringpostembryonic development in C. elegans with significant co-expression in hypodermal seam cells and gut cells,suggesting that these genes have distinct as well as overlapping roles in postembryonic development that may ormay not be related to their established roles in mitosis. Furthermore, we provide evidence, by monitoring seamcell lineage, that one of the checkpoint genes is required for proper postembryonic cell proliferation. Importantly,our research provides the first evidence that postembryonic cell division is more sensitive to SAC loss, in particularMDF-2 loss, than embryonic cell division

Potential Economic Impacts of Allocating More Land for Bioenergy Biomass Production in Virginia

The growing attention to renewable energy and rural development has created greater demand for production of biomass feedstock for bioenergy. However, forest growth rates and the amount of land in most existing forests may not be sufficient to sustainably supply the forest biomass required to support existing forest products industries and the expanding bioenergy industry. Additionally, concerns about agricultural land use competition have dampened expansion of biomass production on agricultural land base. One of the ways to meet the growing forest biomass feedstock demand for bioenergy production is by allocating currently marginal non-forested land for growing bioenergy feedstocks. In Virginia, about 80% of forestland is under nonindustrial private forest ownership. The land use allocation decisions of these private owners are critical for the supply of the forest biomass feedstock to support bioenergy production. We apply a computable general equilibrium model to assess the economy-wide impacts of forestland owners’ willingness to plant pine on non-forested land for woody bioenergy in Virginia. We consider three counterfactual scenarios of biomass feedstock supply increase as intermediate demand for bioenergy production based on forestland owners’ willingness to accept biomass bid prices to set aside more non-forested land for biomass production in Virginia under general equilibrium conditions. Overall, the results show an increase in social welfare and household utility but a marginal decline in GDP. However, increased demand of biomass from logging sector depressed the manufacturing sector (the wood manufacturing sub-sector particularly), which also relies on the logging sector for its intermediate inputs. Results from this study provide insights into the bioenergy land use competition debate, and pathways towards sustainable bioenergy feedstock supply

Intention to deliver in a healthcare facility and healthcare facility‐based delivery rates among women in Akwatia, Ghana

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135204/1/ijgo161.pd

The PRECISE (PREgnancy Care Integrating translational Science, Everywhere) database: open-access data collection in maternal and newborn health

In less-resourced settings, adverse pregnancy outcome rates are unacceptably high. To effect improvement, we need accurate epidemiological data about rates of death and morbidity, as well as social determinants of health and processes of care, and from each country (or region) to contextualise strategies. The PRECISE database is a unique core infrastructure of a generic, unified data collection platform. It is built on previous work in data harmonisation, outcome and data field standardisation, open-access software (District Health Information System 2 and the Baobab Laboratory Information Management System), and clinical research networks. The database contains globally-recommended indicators included in Health Management Information System recording and reporting forms. It comprises key outcomes (maternal and perinatal death), life-saving interventions (Human Immunodeficiency Virus testing, blood pressure measurement, iron therapy, uterotonic use after delivery, postpartum maternal assessment within 48 h of birth, and newborn resuscitation, immediate skin-to-skin contact, and immediate drying), and an additional 17 core administrative variables for the mother and babies. In addition, the database has a suite of additional modules for ‘deep phenotyping’ based on established tools. These include social determinants of health (including socioeconomic status, nutrition and the environment), maternal comorbidities, mental health, violence against women and health systems. The database has the potential to enable future high-quality epidemiological research integrated with clinical care and discovery bioscience

The ability and safety of community-based health workers to safely initiate lifesaving therapies for pre-eclampsia in Ogun State, Nigeria: An analysis of 260 community treatments with MgSO4 and/or methyldopa

Objectives: To evaluate community-based health workers\u27 ability to identify cases of hypertension in pregnancy, safely deliver methyldopa and magnesium sulphate and make referrals when appropriate.Study design: This was part of Nigeria Community-Level Interventions for Pre-eclampsia (CLIP) cluster randomized controlled trial (NCT01911494). Community-based Health Workers (CHW) recruited pregnant women from five Local Government Areas (clusters) and used mobile health aid for clinical assessment of pre-eclampsia.Main outcome measures: The primary outcome was the number of adverse events that occurred after the administration of magnesium sulphate and/or methyldopa to pregnant women by CHWs.Findings: Of 8790 women receiving mobile health-guided care, community-based health workers in Nigeria provided 309 women with hypertension (4.2% of delivered women), and safely administered 142 doses of intramuscular magnesium sulphate. Community Heath Extension Workers (CHEWs) and nurses gave fifty-two and sixty-seven doses of intramuscular magnesium sulphate respectively, twenty-three doses were given by other health care workers (midwives, community health officers, health assistants). The high rate of administration by nurses can be explained by turf protection as well as their seniority within the health system. Also, CHEWs and nurses gave 124 doses of oral methyldopa and 126 urgent referrals were completed. There were no complications related to administration of treatment or referral.Interpretation: These findings demonstrate the ability of community-based health workers to safely administer methyldopa and intramuscular magnesium sulphate. The use of task-sharing, therefore, could drastically reduce the three delays (triage, transport and treatment) associated with high maternal mortality and morbidity in rural communities in low- and middle-income countries

Advancing glioblastoma imaging: Exploring the potential of organic fluorophore-based red emissive carbon dots

Over time, the interest in developing stable photosensitizers (PS) which both absorb and emit light in the red region (650 and 950 nm) has gained noticeable interest. Recently, carbon dots (CDs) have become the material of focus to act as a PS due to their high extinction coefficient, low cytotoxicity, and both high photo and thermal stability. In this work, a Federal and Drug Association (FDA) approved Near Infra-Red (NIR) organic fluorophore used for photo-imaging, indocyanine green (ICG), has been explored as a precursor to develop water-soluble red emissive CDs which possess red emission at 697 nm. Furthermore, our material was found to yield favorable red-imaging capabilities of glioblastoma stem-like cells (GSCs) meanwhile boasting low toxicity. Additionally with post modifications, our CDs have been found to have selectivity towards tumors over healthy tissue as well as crossing the blood-brain barrier (BBB) in zebrafish models

Investigation into Red Emission and Its Applications: Solvatochromic N-Doped Red Emissive Carbon Dots with Solvent Polarity Sensing and Solid-State Fluorescent Nanocomposite Thin Films

In this work, a NIR emitting dye, p-toluenesulfonate (IR-813) was explored as a model precursor to develop red emissive carbon dots (813-CD) with solvatochromic behavior with a red-shift observed with increasing solvent polarity. The 813-CDs produced had emission peaks at 610 and 698 nm, respectively, in water with blue shifts of emission as solvent polarity decreased. Subsequently, 813-CD was synthesized with increasing nitrogen content with polyethyleneimine (PEI) to elucidate the change in band gap energy. With increased nitrogen content, the CDs produced emissions as far as 776 nm. Additionally, a CD nanocomposite polyvinylpyrrolidone (PVP) film was synthesized to assess the phenomenon of solid-state fluorescence. Furthermore, the CDs were found to have electrochemical properties to be used as an additive doping agent for PVP film coatings