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Sub-Basin Valuation of Agriculture: A Crop-Specific Assessment of Groundwater Footprints and Value in California
No full textAbstract: California's agricultural sector supports a global food chain. This industry is enabled by a vast network of surface water supplies and stressed groundwater resources, which enable year-round irrigation of water-intensive crops such as pistachios, almonds, and rice. Due to the 2007-2009 and 2012-2016 droughts, there has been renewed interest in statewide groundwater management, culminating in the 2014 Sustainable Groundwater Management Act (SGMA). However, the nexus of agricultural water consumption of specific crops and their spatially explicit economic value remains unexplored. Openly accessible data for these outcomes are not centrally stored, are spatially and temporally disparate, and have not yet been synthesized for a critical analysis of the groundwater footprint of agriculture in the state. We derive a unique dataset of the estimated economic value of groundwater and surface water used for irrigation, at the county, basin, and sub-basin scales. For the study period of 2007-2017, we synthesize remote sensing, spatial, and tabular data on crop identity, water footprints, and economic value. This synthesis allows us to study trends in crop water consumption, drought resilience responses, and value impacts. A case study of the Delta-Mendota sub-basin provides further insight into historical trends in agricultural groundwater consumption, crop portfolios, and crop switching practices during drought and recovery periods. This dataset can help various stakeholders weigh the economic and environmental costs and benefits of crop- and basin-level groundwater management decisions. It is also expected to improve the current methodology used to prioritize groundwater basins for conservation, and thus inform long-term goals set by basin-level Groundwater Sustainability Agencies under SGMA.Thesis (M.S.)--Tufts University, 2018.Submitted to the Dept. of Civil Engineering.Advisor: Elena Naumova.Committee: Sumeeta Srinivasan, and Magaly Koch.Keywords: Water resources management, Environmental engineering, and Agriculture engineering
The Effects of Landscape Structure and Climate Change on the Movement, Connectivity, and Population Viability of the Hawaiian gallinule (Gallinula galeata sandvicensis)
No full textAbstract: This dissertation examines the effects of anthropogenic landscape change on the population structure, functional connectivity, and extinction risk of the Hawaiian gallinule (Gallinula galeata sandvicensis), an endangered subspecies of waterbird endemic to Hawai`i. Through a combination of field work, population genetic analysis, geospatial analysis, simulation modeling, and meta-analysis of published and unpublished work, I elucidate the behavioral and ecological mechanisms by which landscape structure impacts Hawaiian gallinule populations persisting on the island of O`ahu, Hawai`i. Hawaiian gallinules exhibited severe population declines throughout the late 19th to mid-20th century, a period coinciding with substantial development and reclamation of wetland habitat throughout Hawai`i. Their population on O`ahu has been slowly increasing since the late 1970's, and remaining populations persist in a fragmented, urbanized landscape. I quantified the extent of wetland loss across the archipelago, and investigated the population genetic impacts of this landscape fragmentation, as well as the recent population bottleneck, on the population structure of O`ahu's gallinule population. O`ahu had the greatest extent of wetland loss (in excess of 65%), concentrated particularly in the coastal lowlands, and sampled gallinule subpopulations across O`ahu showed moderately high genetic differentiation (overall microsatellite FST = 0.098, mtDNA FST = 0.248) across small spatial scales (1-35km). Using these genetic data, I tested a variety of biologically-informed movement hypotheses for how gallinules navigate the island's landscape. Models that treated water features like rivers, streams, and drainage canals as corridors for gallinule movement greatly outperformed other potential movement models across different molecular markers, simulation methods, and statistical tests. I next combined my own field observations with previous work from government reports, Masters theses and Doctoral dissertations to generate the first comprehensive review and estimation of the vital rates of Hawaiian gallinules. Finally, I used an individually-based, spatially explicit population model to explore the climate and landscape change impacts on the viability of O`ahu's gallinule population. Sensitivity analysis highlighted the importance of juvenile and adult survival for overall population persistence, and the importance of dispersal in mediating source-sink dynamics on the island. I estimated that O`ahu's major gallinule habitats could lose >40% of their carrying capacity under sea level rise conditions predicted for the next century.Thesis (Ph.D.)--Tufts University, 2018.Submitted to the Dept. of Biology.Advisor: J. Michael Reed.Committee: Elizabeth Crone, Colin Orians, Erik Dopman, and Brian Olsen.Keywords: Conservation biology, Ecology, and Environmental management
Assessing Young Children's Computational Thinking Abilities
No full textAbstract: Computational thinking (CT) is a category of thought processes that allows framing and solving problems with computers, robots and other computational devices. The development of CT abilities through computational learning is increasingly vital to success in our technologically-oriented society. A major barrier to computational learning in schools is the current lack of validated instruments for assessing CT abilities in young children. We have developed a new CT assessment instrument called "TACTIC-KIBO" (Tufts Assessment of Computational Thinking In Children - KIBO version). This instrument uses the KIBO programmable robot to evaluate the CT abilities of kindergarten and early elementary school children in classroom or research settings. TACTIC-KIBO rates overall CT ability into four levels by evaluating performance in seven CT categories that are based upon Bers' Developmentally Appropriate Seven Powerful Ideas of Computational Thinking (Bers 2018). In a pilot study, fifteen 5-7-year olds with various levels of past exposure to the KIBO robot were assessed with this new instrument. The children were also videotaped as they engaged in structured interactive play sessions with the KIBO robot to allow their CT skills to be rated independently by researchers with expertise in assessing CT. Results show a high correlation (r=0.895, p <0.001) between the ratings made with TACTIC-KIBO and expert assessments. TACTIC-KIBO could be easily administered and scored for children with a wide range of CT abilities in an average of 16 minutes per child. Expert ratings of interactive play sessions took longer to perform and were subject to inter-rater variability. Detailed analysis of participants' responses reveals potential areas in which TACTIC-KIBO can be improved in the future. Results of this pilot study are encouraging and provide support for the further development of TACTIC-KIBO as a practical assessment tool for educators and researchers to use when measuring CT abilities in young children.Thesis (M.A.)--Tufts University, 2018.Submitted to the Dept. of Child Development.Advisor: Marina Bers.Committee: Martha Pott, and Brian Gravel.Keywords: Educational tests & measurements, Educational technology, and Early childhood education
Detangling PPI Networks to Uncover Functionally Meaningful Clusters.
No full textWe compare computational methods for decomposing a PPI network into non-overlapping modules. A method is preferred if it results in a large proportion of nodes being assigned to functionally meaningful modules, as measured by functional enrichment over terms from the Gene Ontology (GO). We compare the performance of three popular community detection algorithms that produce non-overlapping clusters with the same algorithms run after the network is pre-processed by removing and reweighting based on the diffusion state distance (DSD) between pairs of nodes in the network. We call this detangling the network. In some cases, we find that detangling the network based on the DSD distance reweighting provides more meaningful clusters. We look at extending to methods that produce overlapping clusters
MOTEL PAPA.
No full textI've become really invested in the idea of prepared spaces, both visible and invisible ones, as a way of talking about how outdated or flawed some of the standards we uphold are. We have motel rooms and gallery spaces that were designed in the 1950s and 1960s and have stayed that way since. We have archetypes of femininity and masculinity and sexuality from the same era that we still endorse culturally. We navigate a lot through systems of assumptions. I like to point to the love/hate relationships we can have with prepared spaces, and to present the feeling of a system not working for us, our work, our expression of ourselves, and our love, now.Keywords: queer, gender expression, sixties, vintage motel, painting, installation, music, portraiture, portraits, figure painting, chromatic, aberration, songs, identity, love, sexuality, outdated failing systems
Mi Dulce Columbia.
No full textSara Pizarro has been commissioned to paint murals around Tufts University and has painted live in major venues such as the House of Blues. Her murals have been displayed on multiple continents and, until now, have been an expression of her passion for empowering women-- illustrating the female figure in both heroic and iconic fashion. Pizarro is graduating from the BFA program at the School of the Museum of Fine Arts at Tufts. Her subject matter has changed during the last year. She moves between multiple two-dimensional mediums -- from illustration to painting -- now focusing on a deep exploration of her own personal thoughts and experiences, including her perception of self
'I that do speak a word may call it again': Reimagining Text, Self, and Progress in Shakespeare.
No full textAn examination of processes of revision in Measure for Measure, The Winter's Tale, and the progression of the Shakespeare canon
Ambient Energy Matrix Isolation Spectroscopy: A Molecular Study of p-Toluenesulfonic Acid Solvation.
No full textClathrate hydrates are water cages that incase hydrophobic gases, such as methane and CO2. They form under extreme conditions (pressure ranging from 9 to several thousand atm, and at cryogenic temperature). They occur naturally in the permafrost and on the continental shelf of the seabed (700 m) where the pressure is about 70 atm. Clathrates are estimated to contain a substantial amount of energy. Extraction of this energy is dangerous and not environmentally favorable, since clathrate hydrates are not stable without its guest gas and at lower pressure environment. Careless extractions could release all the trapped hydrocarbon at once, thus accelerate global warming. Nonetheless, they have the potential to be a good system for cleaning greenhouse gases such as CO2 and as a gas storage and transfer media. To produce these gas hydrate cost-effectively, promoters, such as the hydrotrope pToluenesulfonic acid (pTSA), are used. The molecular mechanism of how promoters interact with water and the guest gas molecule is studied here using a method called Ambient Energy Matrix Isolation Spectroscopy, or AE-MIS. AE-MIS uses carbon tetrachloride (CCl4) matrix to simplify the water spectrum in the mid-IR region. The vibrational signatures of water in CCl4 – the symmetric stretch, asymmetric stretch, and rotation about the symmetry axis – are present because water exists as monomers in CCl4 with quenched rotation about the axes perpendicular to the symmetry axis. Monitoring and interpreting changes of these features when studying water interaction with other molecules can give a molecular insight to puzzling mechanisms of bigger systems. Herein, experimental spectra of small (pTSA)•(H2O)n clusters (n ≤ 10) and large clusters (n ≥ 20) are presented. Peak assignments and a proposed bimodal distribution model are aided by Density Functional Theory (DFT) calculations
Hemodynamic Brain Responses to Happy and Fearful Faces of 7-month-old Infants Linked to Behavioral Inhibition Outcomes at Age 3.
No full textUndergraduate senior thesis with high honors in the department of psychology for a degree in Cognitive and Brain Sciences
P2Y6R Involvement in Glymphatic Pathway Clearance of Amyloid: Molecular and Behavioral Implications for Alzheimer’s Disease.
No full textAlzheimer’s Disease (AD), which is characterized by a progressive impairment in episodic memory as well as other behavioral and cognitive functions, is the most common cause of dementia, affecting about 5.5million people in 2017. It is thought that AD is the result of the accumulation of neurotoxic amyloid protein in the brain resulting from impaired clearance and homeostatic mechanisms in the brain. Dong et al. (in preparation) have identified a prodrug, GC021109, that has been shown to reverse the pathological accumulation of amyloid in the brain and the corresponding decrease of amyloid in the cerebrospinal fluid that is characteristic of AD in both preclinical mouse trials and human phase 1 clinical trials. GC021109 is an activator of the P2Y6 receptor. The relationship between P2Y6 receptors and amyloid clearance is not yet known. The goal of the current project was to elucidate the connection between P2Y6R activity and the glymphatic pathway, a waste clearance pathway in the brain, to determine whether P2Y6R is modulating amyloid clearance via this pathway. Fluorescent tracers were injected into the brain or CSF of mice and the tracers' circulation throughout the glymphatic pathway was compared with and without GC021109 treatment to determine if treatment yielded increased glymphatic pathway circulation of the tracers. Behavioral assessments were also conducted on mouse models of AD to determine the effect GC021109 has on behavioral and cognitive symptoms of AD