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Online 1. 3 Leafs [2019]

  • 3 Leafs (Musician)
  • Stanford (Calif.), February 9, 2019
Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 2. Alexander Ness [2019]

Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 3. Alkimiya Transfer [2019]

Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 4. Analagous Duo [2019]

Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 5. Analysis, evaluation, and improvement of performance-based earthquake engineering damage and loss predictions [2019]

Description
Book — 1 online resource.
Summary
Performance-based earthquake engineering (PBEE) has in many ways revolutionized the thinking about seismic engineering design and acceptable performance of buildings in earthquakes. It is now making its way into commercial engineering design and risk analysis practice, as engineers aim to design better-performing buildings, and holders of mortgage or insurance instruments try to better understand the risk they face from damage to associated buildings. Some parts of the calculations (e.g. structural response) have been extensively assessed and validated. There are few similar studies, however, that focus on the damage and loss predictions. The purpose of this dissertation is to address this, by analyzing, evaluating, and improving the damage and loss predictions. The specific PBEE methodology examined in this dissertation is the FEMA P-58 Seismic Performance Assessment Procedure. FEMA P-58 damage and loss predictions are analyzed, to determine how they are impacted by other parts of the calculations. Firstly, variance-based sensitivity analyses are conducted to investigate the interaction of loss predictions with different inputs to the calculations. Of the six inputs considered in the analyses, it is found that predictions of building repair cost (as a fraction of replacement value) are most sensitive to shaking intensity and building age, while building re-occupancy time predictions are most sensitive to shaking intensity and building lateral system. Secondly, a methodology is developed to quantify the impact of available structural response data from seismic instrumentation on the quality of the damage and loss predictions. The density of instrumentation examined using the methodology ranges from the case in which all floors are instrumented to that in which no floors are instrumented and simplified procedures are used to produce structural response predictions. It is found that the quality of the predictions generally improves as the density of seismic instrumentation increases, but it is not crucial for the density to be very high to achieve reasonable accuracy in both damage and loss predictions (although this may depend on the arrangement of instrumentation within a building). Loss predictions are evaluated using data observed in previous seismic events, to understand the degree to which they reflect real-life consequences of earthquakes. A methodology is developed for evaluating the ability of FEMA P-58 component-level losses to predict damage observed for groups of buildings. It is found in applications of the methodology that FEMA P-58 non-structural component-level loss predictions provide more insight into damage than variations in ground shaking between buildings. Finally, this dissertation includes a number of recommendations for improving non-structural mechanical component fragility functions and associated loss predictions used in FEMA-58 calculations. The fitting technique currently used for the functions does not converge in some cases, and the methodology used to predict anchored mechanical component losses can lead to some unexpected results, such as non-smooth variation of repair costs with anchorage capacity. An alternative statistical technique is proposed for fitting the fragility functions that mitigates the non-convergence problems when fitting and makes predictions that better align with damage observed in past events. A more intuitive methodology for predicting anchored mechanical component losses is also suggested. The findings of this dissertation help to enhance understanding of, and improve, the damage and loss predictions used in the FEMA P-58 seismic performance assessment procedure. They ultimately enable various stakeholders, such as building owners, design professionals, lenders, and insurers, to make more informed decisions about seismic risk.
Also online at

Online 6. Antimatter and Thomas Dimuzio [2019]

Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 7. Applications of atomic layer deposition for next-generation nanoscale devices [2019]

Description
Book — 1 online resource.
Summary
Atomic Layer Deposition (ALD) is a thin film deposition technique that has gained prominence in recent years due to its ability to synthesize highly conformal and uniform films, with precise thickness control and for a wide range of materials. This work explores how the unique properties of ALD films can be leveraged through novel nanofabrication processes to enable higher performance devices. First, a comprehensive characterization of the etch rates of 9 oxide ALD films in 20 wet chemicals and vapor etchants is presented, as knowing the films' etch rates and their compatibility with commonly used processing chemicals is crucially important when integrating them into nanofabrication processes. Second, a new process is described that, by taking advantage of ALD films' excellent properties as etch stop layers for vapor releases, allows the simultaneous release of suspended structures of varying sizes and arbitrary shapes with high accuracy. This so-called "sandbox" process can be incorporated into the fabrication of many kinds of devices, and has been successfully employed for aluminum nitride piezoelectric resonators, resulting in a record high figure of merit. Finally, the development of thermal accelerometers featuring ultrathin suspended platinum thermistors with thicknesses down to 8 nm is presented. Using plasma-enhanced ALD of platinum for the first time in a thermal accelerometer enables a 100x reduction in beam cross-section compared to previous work. Plasma treatments and nucleation layer dependencies of ALD platinum are investigated to further enhance material properties. Novel fabrication processes allow large cavity sizes of up to 500 μm depth and 4000 μm length, resulting in unprecedentedly high aspect ratios exceeding 100,000:1, which confer many benefits such as increased heating efficiency and decreased thermal time constants.
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Online 8. Assessment of physical function from patterns in routine physical activity measured by wearable activity monitors [2019]

  • Agarwal, Vibhu, author.
  • [Stanford, California] : [Stanford University], 2019.
Description
Book — 1 online resource.
Summary
Limitations in physical functioning can lead to dire health and financial consequences. However, the progression of physical function impairment interacts with many different factors, such as organ function, activities and the environment. It is suspected that the complexity of physical function evaluation methods contributes to the low prevalence of function assessments in routine care. Earlier studies have shown that a bidirectional and monotonic relationship exists between physical activity and function. Wearable activity monitors (WAM) -- devices equipped with one or more accelerometers, offer an opportunity to infer physical function from the observed physical activity objectively and at scale. However, efforts to infer function from such activity measurements have been limited. In this dissertation I present methods to infer physical function from daily activity data. Using free-living activity data from the physical activity studies in the Osteoarthritis Initiative, I show that activity measurements obtained by a WAM are sensitive to changes in physical function, if we use an appropriate representation for daily activity. Further, I show that a representation of physical activity that quantifies a subject's engagement in different classes of activity patterns, improves the performance in a physical function classification task. I also demonstrate how such an activity representation may be constructed in an unsupervised manner, obviating the need for time consuming annotation of activity data. Finally, I motivate the case for a composite score of physical function and present two methods for deriving such a score from free-living activity. I also present evaluations of the computed score on predicting key events in the natural history of knee osteoarthritis. Inferring physical function from wearable activity monitors will enable remote monitoring of function, which in turn will facilitate better delivery of care to patients, at a lower cost.
Also online at

Online 9. Association of Primary Care Physician Supply With Population Mortality in the United States, 2005-2015 [2019]

Description
Software/Multimedia
Summary
Importance Recent US health care reforms incentivize improved population health outcomes and primary care functions. It remains unclear how much improving primary care physician supply can improve population health, independent of other health care and socioeconomic factors. Objectives To identify primary care physician supply changes across US counties from 2005-2015 and associations between such changes and population mortality. Design, Setting, and Participants This epidemiological study evaluated US population data and individual-level claims data linked to mortality from 2005 to 2015 against changes in primary care and specialist physician supply from 2005 to 2015. Data from 3142 US counties, 7144 primary care service areas, and 306 hospital referral regions were used to investigate the association of primary care physician supply with changes in life expectancy and cause-specific mortality after adjustment for health care, demographic, socioeconomic, and behavioral covariates. Analysis was performed from March to July 2018. Main Outcomes and Measures Age-standardized life expectancy, cause-specific mortality, and restricted mean survival time. Results Primary care physician supply increased from 196 014 physicians in 2005 to 204 419 in 2015. Owing to disproportionate losses of primary care physicians in some counties and population increases, the mean (SD) density of primary care physicians relative to population size decreased from 46.6 per 100 000 population (95% CI, 0.0-114.6 per 100 000 population) to 41.4 per 100 000 population (95% CI, 0.0-108.6 per 100 000 population), with greater losses in rural areas. In adjusted mixed-effects regressions, every 10 additional primary care physicians per 100 000 population was associated with a 51.5-day increase in life expectancy (95% CI, 29.5-73.5 days; 0.2% increase), whereas an increase in 10 specialist physicians per 100 000 population corresponded to a 19.2-day increase (95% CI, 7.0-31.3 days). A total of 10 additional primary care physicians per 100 000 population was associated with reduced cardiovascular, cancer, and respiratory mortality by 0.9% to 1.4%. Analyses at different geographic levels, using instrumental variable regressions, or at the individual level found similar benefits associated with primary care supply. Conclusions and Relevance Greater primary care physician supply was associated with lower mortality, but per capita supply decreased between 2005 and 2015. Programs to explicitly direct more resources to primary care physician supply may be important for population health.
Importance Recent US health care reforms incentivize improved population health outcomes and primary care functions. It remains unclear how much improving primary care physician supply can improve population health, independent of other health care and socioeconomic factors. Objectives To identify primary care physician supply changes across US counties from 2005-2015 and associations between such changes and population mortality. Design, Setting, and Participants This epidemiological study evaluated US population data and individual-level claims data linked to mortality from 2005 to 2015 against changes in primary care and specialist physician supply from 2005 to 2015. Data from 3142 US counties, 7144 primary care service areas, and 306 hospital referral regions were used to investigate the association of primary care physician supply with changes in life expectancy and cause-specific mortality after adjustment for health care, demographic, socioeconomic, and behavioral covariates. Analysis was performed from March to July 2018. Main Outcomes and Measures Age-standardized life expectancy, cause-specific mortality, and restricted mean survival time. Results Primary care physician supply increased from 196 014 physicians in 2005 to 204 419 in 2015. Owing to disproportionate losses of primary care physicians in some counties and population increases, the mean (SD) density of primary care physicians relative to population size decreased from 46.6 per 100 000 population (95% CI, 0.0-114.6 per 100 000 population) to 41.4 per 100 000 population (95% CI, 0.0-108.6 per 100 000 population), with greater losses in rural areas. In adjusted mixed-effects regressions, every 10 additional primary care physicians per 100 000 population was associated with a 51.5-day increase in life expectancy (95% CI, 29.5-73.5 days; 0.2% increase), whereas an increase in 10 specialist physicians per 100 000 population corresponded to a 19.2-day increase (95% CI, 7.0-31.3 days). A total of 10 additional primary care physicians per 100 000 population was associated with reduced cardiovascular, cancer, and respiratory mortality by 0.9% to 1.4%. Analyses at different geographic levels, using instrumental variable regressions, or at the individual level found similar benefits associated with primary care supply. Conclusions and Relevance Greater primary care physician supply was associated with lower mortality, but per capita supply decreased between 2005 and 2015. Programs to explicitly direct more resources to primary care physician supply may be important for population health.
Collection
Stanford Project for Open Knowledge in Epidemiology (SPOKE)

Online 10. The asymmetric synthesis of acyclic tetrasubstituted stereocenters by palladium-catalyzed allylic alkylation [2019]

Description
Book — 1 online resource.
Summary
Herein are described strategies for the asymmetric synthesis of acyclic tetrasubstituted stereocenters using palladium-catalyzed allylic alkylation. In particular prochiral nucleophiles are exploited for the synthesis of acyclic alpha tertiary hydroxyketones, fully substituted nitroalkanes, and all-carbon quaternary stereocenters. The problem of O-alkylation in benzylic nitronate synthesis was overcome by the use of a decarboxylative asymmetric allylic alkylation of allyl alpha nitroesters. Extensive screening of reaction conditions revealed a unique ligand and solvent combination that proved crucial for achieving high chemo- and enantioselectivity in this challenging reaction. Substrates were readily synthesized via a combinatorial cross-Claisen / alpha arylation protocol, and the method was highlighted by chemoselective functional group interconversions of a highly elaborated substrate. Boronic acids were exploited as templates of ene-diolate systems to solve a longstanding problem of direct asymmetric C-alkylation of alpha hydroxyketones. This process was rendered chemo-, regio-, and enantioselective in allylation reactions, while point and axial chirality were efficiently set in allylic alkylations of racemic allene substrates via a dynamic kinetic asymmetric transformation. This method represents one of the first examples where point and axial chirality are effectively set in allylic alkylation. As a follow-up to this work, enol boranes were found to be effective pronucleophiles in palladium-catalyzed allylic alkylation reactions. A 1,4-hydroboration reaction was exploited for the thermal generation of regio-defined enol boranes, and a unique electron-deficient ligand was found to exhibit differential reactivity in the subsequent alkylation reaction. This chemistry was further extended to provide a room temperature alkylation of ester derived enol boranes, in particular, unactivated esters. A preparative application was demonstrated in the synthesis of acyclic all-carbon quaternary stereocenters, where the stereoselectivity was a function of the identities of a chiral auxiliary, a chiral ligand, and a designer leaving group. It is hoped that this chemistry may spur broader interest in metal-catalyzed reactions of enol boranes.
Also online at

Online 11. Augmenting human driving via steering wheel skin stretch haptics [2019]

Description
Book — 1 online resource.
Summary
Cars are growing smarter as they incorporate improvements in sensing, computing and communication. They increasingly are able to monitor the environment, detect impending events, and make decisions, sometimes with higher speed and accuracy than is possible for the human driver. While this helps drivers in many ways, it also reduces situational awareness and driver ability to respond to emergencies, and it remains an open question how best to communicate this information. This thesis examines haptic skin stretch at the steering wheel as a way to improve communication from car to driver and augment driving ability. A steering wheel with an embedded skin stretch display was designed that is compact, lightweight, and allows holding at any position. Rotational motion of the front surface of the rim produces lateral deformation of the skin of the hands, stimulating slowly- and rapidly-adapting mechanoreceptors. The resulting haptic stimuli communicate magnitude, direction, and speed information. This thesis describes a series of experiments with this device characterizing the abilities of humans to perceive the feedback and react appropriately in various driving scenarios. In the first, human ability to perceive directional information in a driving vehicle in suburban traffic was assessed, with results generally consistent with those in stationary applications; however, a higher and especially faster rate of stretch application was preferred. In the second experiment, tests are conducted to determine whether drivers can correctly perceive and react to skin stretch navigation cues, which are compared to audio navigation cues during an auditory distraction task simulating a phone call. Results showed haptic feedback was at least as accurate as audio feedback and was less distracting. In the third experiment, human ability to utilize skin stretch for obstacle avoidance is examined: in particular, whether they could predict the size and location of obstacles. Subjects were found to perform correct maneuvers with high accuracy, modifying both maneuver direction and size based on the stimulus. Finally, an experiment in a different application, medical needle guidance, provided general insight in how best to provide steering information through skin deformation. Particular attention is given to the ability of skin stretch to alert the driver about impending events, inform about direction, and communicate the magnitude of an event. Results show that all three types of information can be conveyed, with attention to details of how skin stretch is imparted in terms of stimulus pattern, frequency, and magnitude.
Also online at

Online 12. Berlin Duo [2019]

  • Berlin Duo (Musician)
  • Stanford (Calif.), February 9, 2019
Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 13. Blood of Chinnamastika [2019]

Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 14. Bloop and Quack [2019]

Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 15. Blue Boys [2019]

  • Blue Boys (Musician)
  • Stanford (Calif.), March 13, 2019
Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 16. Board of Trustees annual retreat [2019]

IIIF Drag-n-drop
Description
Image — 1 photograph
Summary
These were taken on April 8, 2019 at Point Lobos State Natural Reserve. The board of trustees was at its annual retreat (held this year in Monterey). A group went on a hike at Point Lobos led by Mark Denny, Director, Hopkins Marine Station, and Steve Graham, Dean, School of Earth, Energy & Environmental Sciences (Stanford Earth). With a biologist and geologist as leaders, the hike was informational, beautiful and fun!
These were taken on April 8, 2019 at Point Lobos State Natural Reserve. The board of trustees was at its annual retreat (held this year in Monterey). A group went on a hike at Point Lobos led by Mark Denny, Director, Hopkins Marine Station, and Steve Graham, Dean, School of Earth, Energy & Environmental Sciences (Stanford Earth). With a biologist and geologist as leaders, the hike was informational, beautiful and fun!
Collection
Stanford University, Board of Trustees, meeting records, 1898-2016 (inclusive)

Online 17. Challenges in CT with photon counting detectors [2019]

Description
Book — 1 online resource.
Summary
With many attractive attributes including improved tissue characterization, reduced noise, and lower dose, photon counting detectors (PCDs) with multiple energy bins are being considered for clinical CT systems. A major problem with PCDs is the slow count rate, resulting in count rate loss and pulse pileup. Another challenge to PCDs with multiple energy bins is the large amount of projection data acquired that must be transferred in real time through slip rings to data storage subsystems, causing a bandwidth bottleneck problem. Our goal is to address these challenges with a dynamic bowtie filter, a pulse pileup modeling, and a compression algorithm for PCD projection data. A dynamic bowtie modulates flux distribution as a function of fan and view angles to reduce dose, scatter, and detector dynamic range. One approach, the piecewise-linear attenuator (Hsieh and Pelc, Med Phys 2013), consists of multiple wedges, each of which covers a different fan angle range and is moved in the axial direction to change the thickness seen in an axial slice. Our implementation of the filter with precision components and a control algorithm reduces the detected flux dynamic range to 42 for a chest and 25 for an abdomen, corresponding to a reduction factor of 5 and 11 from the object scans without the bowtie. The thickness profile of the piecewise-linear attenuator is proportional to wedge position and is sensitive to the precision of wedge control. Thus, we propose another dynamic bowtie design called a fluid-filled dynamic bowtie filter (FDBF), a two-dimensional array of small binary elements (filled or empty), that may be more reproducible due to digital control. On average, for simulated scans of chest, abdomen, and shoulder sections of an anthropomorphic phantom, the proposed FDBF reduces the maximum-count-rate required of a PCD to 1.2 Mcps/mm2, which is 55.8 and 3.3 times lower than the max-count-rate of the conventional bowtie and the piecewise-linear bowtie, respectively. For the pulse pileup effect, the performance of several analytical models are dependent on the assumptions used, including the assumed pulse shape which could differ from the actual one. From our sensitivity analysis of a pileup model by Taguchi et al. (Med Phys, 2010), the accuracy of some parameters such as the deadtime are more important than others, and they matter more with increasing count rate. For the bandwidth problem, we explored the use of data compression that could be performed prior to transmission through the slip ring. Utilizing the dependencies in the multi-energy data, our proposed compressor achieves an average compression ratio of 2.25:1 for lossless compression and 4.27:1 for lossy compression.
Also online at

Online 18. Characterization of patients who report use of opioids and/or cannabis in a tertiary referral pain management center [2019]

Description
Book
Summary
Background. Chronic pain is a disease that affects more than 100 million Americans, bearing $635 billion on US economy annually. There are limited treatment options and even more limited evidence to guide their use. Opioids have long been a common treatment for patients with chronic pain, but these drugs are associated with significant morbidity and mortality. Some scientists advocated use of cannabis as an alternative for opioids; however, a growing number of patients are now using a combination of opioid and cannabis. There is a need to characterize the impact of the combination of opioids and cannabis which served as the motivation for this investigation. We first studied characteristics (measures about physical, psychological and social distress) of patients with chronic pain who report or deny use of opioids and/or cannabis. We then compared utilization of healthcare resources among these groups of patients. Methods. Stanford Pain Management Center has been using a learning healthcare system – Collaborative Health Outcomes Information Registry (CHOIR) – since 2012. CHOIR leverages NIH Patient Reported Outcomes Measure Information System (PROMIS) with legacy pain and treatment questions. We used the initial surveys of patients in this registry to compare patients in four groups: patient who report use of (1) neither opioid nor cannabis (reference group); (2) opioid only; (3) cannabis only; and (4) combination of opioid and cannabis. We used analysis of variance and chi-square to compare PROMIS measures and pain intensity between these groups. We then used logistic (emergency room visit and overnight hospital stay) and linear (number of physician visits) regression to compare healthcare utilization among these groups after adjustment for age, sex and variables found significantly different in previous analysis. Results. Patients who report use of opioid and/or cannabis experience higher levels of physical, psychological and social distress across multiple domains. Specifically, these patients experienced higher levels of pain intensity and pain catastrophizing; their pain interferes more with their life and causes more pain related behavior. These patients are more depressed, anxious and angry; they have poorer sleep and are not as satisfied with their social roles and activities. Moreover, they utilize higher level of healthcare resources. After adjustment for other variables, the patients who report use of opioid and cannabis have 1.29 (95% confidence interval of 1.04-1.60) times higher odds of visiting emergency room within 90 days leading to their visit at our clinic; they also have 1.6 (95% confidence interval of 1.26-2.04) times higher odds of staying overnight at the hospital within the same time period. These patients also report on average 1.51 (95% confidence interval of 0.68-2.43) more physician visits within the same period; this number is 0.93 (95% confidence interval of 0.47-1.39) for patients who report use of opioid only and 0.92 (95% confidence interval of 0.27-1.57) for patients who report use of cannabis only. Conclusion. Our findings suggest that use of opioid and/or cannabis is associated with worse outcome and higher healthcare utilization. As such, it will be important to characterize the trajectory of these patients in a prospective longitudinal study.
Background. Chronic pain is a disease that affects more than 100 million Americans, bearing $635 billion on US economy annually. There are limited treatment options and even more limited evidence to guide their use. Opioids have long been a common treatment for patients with chronic pain, but these drugs are associated with significant morbidity and mortality. Some scientists advocated use of cannabis as an alternative for opioids; however, a growing number of patients are now using a combination of opioid and cannabis. There is a need to characterize the impact of the combination of opioids and cannabis which served as the motivation for this investigation. We first studied characteristics (measures about physical, psychological and social distress) of patients with chronic pain who report or deny use of opioids and/or cannabis. We then compared utilization of healthcare resources among these groups of patients. Methods. Stanford Pain Management Center has been using a learning healthcare system – Collaborative Health Outcomes Information Registry (CHOIR) – since 2012. CHOIR leverages NIH Patient Reported Outcomes Measure Information System (PROMIS) with legacy pain and treatment questions. We used the initial surveys of patients in this registry to compare patients in four groups: patient who report use of (1) neither opioid nor cannabis (reference group); (2) opioid only; (3) cannabis only; and (4) combination of opioid and cannabis. We used analysis of variance and chi-square to compare PROMIS measures and pain intensity between these groups. We then used logistic (emergency room visit and overnight hospital stay) and linear (number of physician visits) regression to compare healthcare utilization among these groups after adjustment for age, sex and variables found significantly different in previous analysis. Results. Patients who report use of opioid and/or cannabis experience higher levels of physical, psychological and social distress across multiple domains. Specifically, these patients experienced higher levels of pain intensity and pain catastrophizing; their pain interferes more with their life and causes more pain related behavior. These patients are more depressed, anxious and angry; they have poorer sleep and are not as satisfied with their social roles and activities. Moreover, they utilize higher level of healthcare resources. After adjustment for other variables, the patients who report use of opioid and cannabis have 1.29 (95% confidence interval of 1.04-1.60) times higher odds of visiting emergency room within 90 days leading to their visit at our clinic; they also have 1.6 (95% confidence interval of 1.26-2.04) times higher odds of staying overnight at the hospital within the same time period. These patients also report on average 1.51 (95% confidence interval of 0.68-2.43) more physician visits within the same period; this number is 0.93 (95% confidence interval of 0.47-1.39) for patients who report use of opioid only and 0.92 (95% confidence interval of 0.27-1.57) for patients who report use of cannabis only. Conclusion. Our findings suggest that use of opioid and/or cannabis is associated with worse outcome and higher healthcare utilization. As such, it will be important to characterize the trajectory of these patients in a prospective longitudinal study.
Collection
Epidemiology & Clinical Research Masters Theses

Online 19. Clarke Robinson and Arjun Mendiratta [2019]

Description
Music recording — 1 audio file
Collection
Stanford University, KZSU, records, 1976-1977

Online 20. Classified : the effects of English learner status on high school and college opportunities [2019]

Description
Book — 1 online resource.
Summary
Every one in ten students in US public K-12 schools today is an English Learner (EL). Educators are becoming increasingly concerned over their low achievement and high school graduation rate. Qualitative research shows that EL underachievement can be attributed to limited access to a rigorous curriculum. This dissertation compares the level of access ELs and non-ELs have to secondary and postsecondary educational opportunities. The first study uses regression analysis to compare the high school course-taking and credit-earning patterns of non-ELs and ELs with various lengths of EL status. The second study identifies the causal relationship between summer credit recovery and newcomer ELs' academic outcomes using a difference-in-differences-in-differences design. The third study applies a regression discontinuity design to estimate the causal impact of EL classification on high school graduation and college attendance. I find that academic course-taking vary substantially not only between ELs and non-ELs but also within the EL population. Summer credit recovery significantly increases course access for recent immigrants. Initial EL classification has no significant effects on graduation and college enrollment, but reclassification just before school transition (5th and 8th grade) may impact graduation and, conditional on college attendance, college choice and enrollment intensity. This dissertation extends our understanding of ELs' academic access in high school, improving upon previous studies with detailed analyses on a much larger sample. The findings also inform policymakers of inequities in educational opportunities by EL status and provide evidence for the efficacy of targeted interventions.
Also online at