Three Essays in Real Estate Economics

This dissertation consists of three separate essays which examine the impact of home characteristics and state and local policy on home transaction prices. Chapter 1 investigates the role that pedestrian infrastructure and the walkability of the area surrounding a home has in influencing home transaction prices. Through the use of computer vision procedures to gather new data from images, Chapter 2 explores how practical and aesthetic attributes of the exterior of a home are reflected in a home\u27s sale price. Chapter 3 estimates the impact that legalization of recreational marijuana and the subsequent establishment of marijuana dispensaries has had on home transaction prices in Denver, Colorado

Mirror, Mirror in the Chamber: Effects of Social Stimuli on Operant Behavior

The variables affecting social behavior are myriad, making the prediction and control of behavior occurring in social contexts relatively difficult. One can attempt to create a controlled social context in the laboratory by introducing a second organism into an operant chamber. To investigate effects of social stimuli on operant responding, key pecking responses of three pigeons were maintained on a variable-interval (VI) schedule of reinforcement in Experiment 1, and the key pecking responses of three additional pigeons were maintained on a three-component multiple schedule in Experiment 2. The components included a variable-ratio (VR) schedule, a fixed-interval (FI) schedule, and a differential reinforcement of low rate behavior (DRL) schedule. No social stimuli were present in the operant chamber during the baseline conditions of either experiment. During experimental conditions a mirror was introduced into the operant chamber to simulate the presence of another organism. The mirror covered one side wall of the chamber adjacent to the work panel containing the response key. Relative decreases in rates of responding were observed during each experiment when the pigeons had access to their reflections compared to when no mirror was present. Response rates returned to baseline levels when the mirror was removed in the subsequent conditions, suggesting that access to visual-social stimuli disrupted pigeon behavior controlled by different schedules of reinforcement

Comparing Common Procedures Used to Manipulate Reinforcer Magnitude

Reinforcer magnitude is one of several parameters of reinforcement. In the present study, it referred to the quantitative value of the reinforcer in terms of duration of access to a finite supply of grain pellets. Pigeons responded on concurrent-chain schedules earning one of several reinforcer durations depending on response allocation and experimental conditions. Experiment 1 consisted of relatively long reinforcer durations available for completing one chain compared to relatively short durations available on the other. Response allocation in the initial link determined the reinforcer duration, but responses in the terminal link produced no change in the upcoming reinforcer. This arrangement allowed for the comparison of response-correlated and experimenter-controlled changes in reinforcer magnitude in terms of the control by reinforcer magnitude they produced. Additional changes in reinforcer durations were programmed between experimental conditions to allow for comparisons of within-sessions and between-conditions changes in magnitude as well. Experiment 2 was procedurally similar to the first, but the total reinforcer duration was identical for each chan. Instead, reinforcer durations were segmented into bins on one chain and kept continuous on the other (e.g., two 4-s reinforcers separated by a brief blackout period compared to one, continuous 8-s reinforcer). Control by reinforcer magnitude was most apparent when changes were response correlated and within-sessions, but behavior change was also observed on the between-conditions scale. No magnitude effects were observed in changes in magnitude were experimenter controlled (i.e., not correlated to behavior). Further, the observed effects seemed to be mediated by eating efficiency. It is recommended that future research on reinforcer magnitude include thorough measurement of the consummatory chain to fully describe the role of eating efficiency in control by reinforcer magnitude

Heteronuclear ionizing collisions between laser-cooled metastable helium atoms

We have investigated cold ionizing heteronuclear collisions in dilute mixtures of metastable (2 3S1) 3He and 4He atoms, extending our previous work on the analogous homonuclear collisions [R. J. W. Stas et al., PRA 73, 032713 (2006)]. A simple theoretical model of such collisions enables us to calculate the heteronuclear ionization rate coefficient, for our quasi-unpolarized gas, in the absence of resonant light (T = 1.2 mK): K34(th) = 2.4*10^-10 cm^3/s. This calculation is supported by a measurement of K34 using magneto-optically trapped mixtures containing about 1*10^8 atoms of each species, K34(exp) = 2.5(8)*10^-10 cm^3/s. Theory and experiment show good agreement.Comment: 8 pages, 6 figure

Experimental evidence of a dynamic Jahn-Teller effect in C+60.

Detailed analysis of the highest occupied molecular orbital band shape in the photoelectron spectrum of gaseous C60 reveals a dynamic Jahn-Teller effect in the ground state of C+60. The direct observation of three tunneling states asserts a D3d geometry for the isolated cation, originating from a strong vibronic coupling. These results show that the ionic motion plays an important role in the electron-phonon interaction

Characterisation of a new VUV beamline at the Daresbury SRS using a dispersed fluorescence apparatus incorporating CCD detection

The design and performance of a new normal incidence monochromator at the Daresbury Synchrotron Radiation Source, optimised for experiments requiring high flux of vacuum-UV radiation, are described. The re-developed beamline 3.1, based on the Wadsworth design of monochromator, is the source of tunable vacuum-UV photons in the range 4 – 31 eV, providing over two orders of magnitude more flux than the vacuum-UV, Seya monochromator in its previous manifestation. The undispersed and dispersed fluorescence spectra resulting from photoexcitation of N$_2$, CO$_2$, CF$_4$ and C$_6$F$_6$ are presented. Emitting species observed were N$_2^+$ B$^2\Sigma_u^+$ - X$^2\Sigma_g^+$, CO$_2^+$ A$^2\Pi_u$ - X$^2\Pi_g$ and B$^2\Sigma_u^+$ - X$^2\Pi_g$, CF$_4$$^+$ C$^2$T$_2$ - X$^2$T$_1$ and C$^2$T$_2$ - A$^2$T$_2$, CF$_3$* $^2$A$^’_2$ - $^2$A$^”_2$, and C$_6$F$_6^+$ B$^2$A$_{2u}$ - X$^2$E$_{1g}$. A CCD multi-channel detector has significantly reduced the time period needed to record dispersed fluorescence spectra with a comparable signal-to-noise ratio

Pete and the Missing Scissors: a primary literature-focused case study that highlights the impact of SARS-CoV-2 on splicing

This case study was designed to help students explore the molecular mechanisms of the spliceosome and how SARS-CoV-2 impacts host cell spliceosomal function while interpreting figures from primary literature (A. K. Banjeree, et al., Cell 183:1325–1339, e1–e10, 2020, https://doi.org/10.1016/j.cell.2020.10.004). “Pete and the Missing Scissors” was designed and implemented in the spring of 2022 and fall of 2022 in two large-enrollment (150+) introductory molecular biology courses at a large, public research institution. The case study was formatted in alignment with the National Center for Case Study Teaching in Science (NCCSTS) framework, which has been shown to be an effective, student-centered approach to teaching complex biological concepts at the undergraduate level. The case study had four student learning objectives (SLOs) that aligned with Bloom’s Revised Taxonomy and required students to develop an understanding of the molecular mechanisms of splicing and analyze and interpret a figure from primary literature. Both formative and summative assessment questions are included in this activity, with each question mapping to one of the case study SLOs. Summative assessment questions were given in a pre-/post-manner, and a paired t-test was used to evaluate differences between students’ pre- and post-assessment scores. Assessment results demonstrated that students in both courses mastered each of the SLOs of this case study, given the significant increase in post-assessment scores compared to the pre-assessment. These findings indicate that the “Pete and the Missing Scissors” case study is an effective approach to develop students’ understanding of the spliceosome, as well as ability to interpret figures from primary literature

Cutaneous Botryomycosis in Two Pet Rabbits

A 5-year-old male neutered rabbit was presented for assessment of multiple abscesses, which had appeared suddenly over the ventrum, perineum and hindlimbs over the previous few days. Thirteen abscesses were surgically excised. Culture revealed Pseudomonas aeruginosa and histopathological examination confirmed a diagnosis of botryomycosis. However, despite follow up antimicrobial treatment and repeat surgeries, lesions continued to recur. The second case, a 3-year-old male neutered rabbit presented for routine vaccination. On physical examination, multiple small nodules were palpated over the right shoulder region. Surgical excision was performed and histopathology again yielded a diagnosis of botryomycosis. So far, no recurrence has been seen in this case. Botryomycosis is a rare chronic pyogranulomatous infection and naturally occurring disease has not been previously reported in pet rabbits. These cases highlight the challenges of treatment and the importance of prompt diagnosis