Three Essays in Urban Policy

The papers in this dissertation share a common theme of measuring policy effects in urban markets. Though focusing on different outcomes – access to rental housing, property values, and school enrollments – the desire to understand how policy influences the composition of an urban ecosystem provides the link. A particular emphasis is placed on housing, because housing is simultaneously and a basic requirement for humans to thrive and the primary source of most local finance in the U.S. When policy affects housing, be it directly or indirectly, it can have important and far-reaching consequences. Understanding the intended and unintended consequences of urban policy is thus central to this dissertation research and my future research agenda. Chapter 1 offers the first evidence of differential treatment occurring across the broad spectrum of racial and protected classes covered under the law. Employing a fully randomized correspondence audit design and a sample of more than 9,500 online housing advertisements, the study offers insight about which protected groups experience the most/least favorable treatment when searching for housing. This study employs a new signaling strategy in order to provide the first evidence of how landlord treatment of rental housing applicants varies across the spectrum of protected classes. The findings suggest rental-housing providers have preferences about tenants and make decisions based on signals communicated in inquiry emails from potential applicants. The findings also suggest differential treatment is generally consistent with theory of agent-based statistical discrimination. Chapter 2 presents an experiment designed to influence rental agent behavior to increase equal treatment in rental housing. The purpose is to test whether property owners and rental agents will change their behavior in response to being informed about their obligations under fair housing law. The project thus conducts a randomized experiment employs a correspondence housing audit methodology to measure the impact, representing the first time in which the audit methodology is employed to measure the effect of a randomized experiment. The results of the experiment consistently suggest the group of landlords who received information about fair housing law responded at a higher rate than did those who did not receive the treatment email. The primary contribution of this paper, then, is to demonstrate a unique opportunity to test policy interventions aimed at reducing discrimination in a real housing market and at a very low cost. My hope is that the method will be modified and expanded by fair housing agencies, advocates, and other institutions to test and implement policy interventions in hopes of reducing barriers to access in housing. Chapter 3 examines the impact of a place-based program on urban property values and school enrolments. A recent trend in place-based policy targets college attainment by offering tuition scholarships for qualified students in under-resourced public schools. In an era of rising college costs, these programs represent a potentially large financial benefit to those living within the attendance zones of qualifying schools. The benefit of such programs should be capitalized into local property values and school district enrolment, as programs are directly linked to attendance zones. This research thus examines the impact a large scholarship program, Say Yes to Education, has on school enrolments and property values in upstate New York. Examining district enrollment from 2000 through 2014, the analysis finds that after years of steady declines in enrollments, both Syracuse and Buffalo saw enrollment increases that coincide with the adoption of the Say Yes to Education program. These increases occurred at different points in time in each city. The housing values results provide some evidence that increases in housing prices accompanied the adoption of Say Yes in Syracuse, but not in Buffalo. These results are consistent with findings that enrolment growth in Buffalo may have been driven by students who would otherwise have attended private schools, while enrollment growth in Syracuse may have been driven by students who would otherwise have attended school in the surrounding suburbs. Combined with the enrolment effects, the analysis suggests that the ability of place-based scholarships to attract residents into a central city is likely to depend on both the specific provisions of the program and the context in which it is implemented

Mechanical properties of borothermally synthesized ZrB2

Mechanical properties of borothermally synthesized, highly pure ZrB2 were tested at room and elevated temperatures. Commercially available ZrB2 powder typically contains 1 to 4 wt % hafnium which has been shown to lower thermal properties of dense ZrB2 ceramics. Further, commercial grade ZrB2 contains other impurities (0.6 wt% O, 0.11 wt% N, 0.04 wt% Fe and others) which are also known to decrease its high-temperature mechanical strength. Purer grades of zirconia and boron powders, containing \u3c 75 ppm hafnium and \u3c0.5 wt% of other metal impurities, were reacted to produce ZrB2 for room and elevated temperature mechanical property studies. The zirconia and boron powders were reacted at 1000°C in a graphite vacuum furnace for two hours. The synthesized ZrB2 powder was then rinsed with methanol to remove boria from its surfaces, sieved with a #45 mesh, and hot pressed to near full density with 32 MPa applied pressure in a flowing argon atmosphere at 2100°C. The hot pressed billets were machined to ASTM standard test bars with the flexure surface polished to 1 um. Young’s modulus, Vickers Hardness, fracture toughness, and four-point bend strength were measured, and the results will be discussed

Room-Temperature Mechanical Properties of a High-Entropy Diboride

The mechanical properties of a (Hf,Mo,Nb,Ta,W,Zr)B2 high-entropy ceramic were measured at room temperature. A two-step synthesis process was utilized to produce the (Hf,Mo,Nb,Ta,W,Zr)B2 ceramics. The process consisted of a boro/carbothermal reduction reaction followed by solid solution formation and densification through spark plasma sintering. Nominally, phase pure (Hf,Mo,Nb,Ta,W,Zr)B2 was sintered to near full density (8.98 g/cm3) at 2000°C. The mean grain size was 6 ± 2 µm with a maximum grain size of 17 µm. Flexural strength was 528 ± 53 MPa, Young\u27s modulus was 520 ± 12 GPa, fracture toughness was 3.9 ± 1.2 MPa·m1/2, and hardness (HV0.2) was 33.1 ± 1.1 GPa. A Griffith-type analysis determined the strength limiting flaw to be the largest grains in the microstructure. This is one of the first reports of a variety of mechanical properties of a six-component high-entropy diboride

Orientale and South Pole-Aitken basins on the Moon: Preliminary Galileo imaging results

During the Earth-Moon flyby the Galileo Solid State Imaging System obtained new information on the landscape and physical geology of the Moon. Multicolor Galileo images of the Moon reveal variations in color properties of the lunar surface. Using returned lunar samples as a key, the color differences can be interpreted in terms of variations in the mineral makeup of the lunar rocks and soil. The combined results of Apollo landings and multicolor images from Galileo allow extrapolation of surface composition to areas distant from the landing sites, including the far side invisible from Earth

Analysing the impact of living in a rural setting on the presentation and outcome of colorectal cancer : A prospective single centre observational study

Peer reviewedPostprin

Challenges in the Search for Perchlorate and Other Hydrated Minerals With 2.1-μm Absorptions on Mars

A previously unidentified artifact has been found in Compact Reconnaissance Imaging Spectrometer for Mars targeted I/F data. It exists in a small fraction (<0.05%) of pixels within 90% of images investigated and occurs in regions of high spectral/spatial variance. This artifact mimics real mineral absorptions in width and depth and occurs most often at 1.9 and 2.1 μm, thus interfering in the search for some mineral phases, including alunite, kieserite, serpentine, and perchlorate. A filtering step in the data processing pipeline, between radiance and I/F versions of the data, convolves narrow artifacts (“spikes”) with real atmospheric absorptions in these wavelength regions to create spurious absorption-like features. The majority of previous orbital detections of alunite, kieserite, and serpentine we investigated can be confirmed using radiance and raw data, but few to none of the perchlorate detections reported in published literature remain robust over the 1.0- to 2.65-μm wavelength range

Spectral and stratigraphic mapping of hydrated sulfate and phyllosilicate-bearing deposits in northern Sinus Meridiani, Mars

We present detailed stratigraphic and spectral analyses that focus on a region in northern Sinus Meridiani located between 1°N to 5°N latitude and 3°W to 1°E longitude. Several stratigraphically distinct units are defined and mapped using morphologic expression, spectral properties, and superposition relationships. Previously unreported exposures of hydrated sulfates and Fe/Mg smectites are identified using MRO CRISM and MEX OMEGA near‐infrared (1.0 to 2.5 µm) spectral reflectance observations. Layered deposits with monohydrated and polyhydrated sulfate spectral signatures that occur in association with a northeast‐southwest trending valley are reexamined using highresolution CRISM, HiRISE, and CTX images. Layers that are spectrally dominated by monohydrated and polyhydrated sulfates are intercalated. The observed compositional layering implies that multiple wetting events, brine recharge, or fluctuations in evaporation rate occurred. We infer that these hydrated sulfate‐bearing layers were unconformably deposited following the extensive erosion of preexisting layered sedimentary rocks and may postdate the formation of the sulfate‐ and hematite‐bearing unit analyzed by the MER Opportunity rover. Therefore, at least two episodes of deposition separated by an unconformity occurred. Fe/Mg phyllosilicates are detected in units that predate the sulfateand hematite‐bearing unit. The presence of Fe/Mg smectite in older units indicates that the relatively low pH formation conditions inferred for the younger sulfate‐ and hematitebearing unit are not representative of the aqueous geochemical environment that prevailed during the formation and alteration of earlier materials. Sedimentary deposits indicative of a complex aqueous history that evolved over time are preserved in Sinus Meridiani, Mars

Nitrogen partitioning and remobilization in relation to leaf senescence, grain yield and protein concentration in Indian wheat cultivars

© 2020 The Authors Nitrogen (N) fertilizer represents a significant cost for the grower and may also have environmental impacts through nitrate leaching and N2O (a greenhouse gas) emissions associated with denitrification. The objectives of this study were to quantify the genetic variability in N partitioning and N remobilization in Indian spring wheat cultivars and identify traits for improved grain yield and grain protein content for application in breeding N-efficient cultivars. Twenty-eight bread wheat cultivars and two durum wheat cultivars were tested in field experiments in two years in Maharashtra, India. Growth analysis was conducted at anthesis and harvest to assess above-ground dry matter (DM) and dry matter and N partitioning. Flag-leaf photosynthesis rate (Amax), flag-leaf senescence rate and canopy normalized difference vegetation index (NDVI) were also assessed. Significant N × genotype level interaction was observed for grain yield and N-use efficiency. There was a positive linear association between post-anthesis flag-leaf Amax and grain yield amongst the 30 genotypes under high N (HN) conditions. Flag-leaf Amax was positively associated with N uptake at anthesis (AGNA). Under both HN and low N (LN) conditions, higher N uptake at anthesis was associated with delayed onset of flag-leaf senescence and higher grain yield. Under N limitation, there was a genetic negative correlation between grain yield and grain protein concentration. Deviation from this negative relationship (grain protein deviation or GPD) was related to genotypic differences in post-anthesis N uptake. It is concluded that N uptake at anthesis was an important determinant of flag-leaf photosynthesis rate and grain yield under high N conditions; while post-anthesis N uptake was an important determinant of GPD of wheat grown under low to moderate N conditions in India

Internal Characteristics of Phobos and Deimos from Spectral Properties and Density: Relationship to Landforms and Comparison with Asteroids

Compositional interpretations of new spectral measurements of Phobos and Deimos from Mars Express/OMEGA and MRO/CRISM and density measurements from encounters by multiple spacecraft support refined estimates of the moons' porosity and internal structure. Phobos' estimated macroporosity of 12-20% is consistent with a fractured but coherent interior; Deimos' estimated macroporosity of 23-44% is more consistent with a loosely consolidated interior. These internal differences are reflected in differences in surface morphology: Phobos exhibits a globally coherent pattern of grooves, whereas Deimos has a surface dominated instead by fragmental debris. Comparison with other asteroids .110 km in diameter shows that this correspondence between landforms and inferred internal structure is part of a pervasive pattern: asteroids interpreted to have coherent interiors exhibit pervasive, organized ridge or groove systems, whereas loosely consolidated asteroids have landforms dominated by fragmental debris and/or retain craters >1.3 body radii in diameter suggesting a porous, compressible interior

Mineralogy of the MSL Curiosity landing site in Gale crater as observed by MRO/CRISM

Orbital data acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and High Resolution Imaging Science Experiment instruments on the Mars Reconnaissance Orbiter (MRO) provide a synoptic view of compositional stratigraphy on the floor of Gale crater surrounding the area where the Mars Science Laboratory (MSL) Curiosity landed. Fractured, light-toned material exhibits a 2.2 µm absorption consistent with enrichment in hydroxylated silica. This material may be distal sediment from the Peace Vallis fan, with cement and fracture fill containing the silica. This unit is overlain by more basaltic material, which has 1 µm and 2 µm absorptions due to pyroxene that are typical of Martian basaltic materials. Both materials are partially obscured by aeolian dust and basaltic sand. Dunes to the southeast exhibit differences in mafic mineral signatures, with barchan dunes enhanced in olivine relative to pyroxene-containing longitudinal dunes. This compositional difference may be related to aeolian grain sorting