1983 research outputs found
Sort by
The Link between Buildings and Cognitive Performance
No full textIn North America, buildings account for an estimated 40% of total energy use and carbon emissions (Nägeli et al., 2018) and are where people spend over 90% of their time (Klepeis et al., 2001). A historical focus on energy efficiency has led to strategies that often degrade indoor environmental quality and in turn, occupant health (A. K. Persily & Emmerich, 2012). Recent attention has shifted towards designing and operating buildings for human health, but there are still questions around the benefits of building operation for human occupants and how to balance these considerations with building energy expenditure. Building heating, ventilation, and air conditioning systems are one pervasive building component that are key to this balance since these systems consume substantial amounts of energy to thermally condition and ventilate indoor spaces, which in turn, impacts occupant health in many ways. Much of the current building stock is operated to conditions set forth by standards that are not designed to promote human health. Accordingly, substantial amounts of energy are being consumed to condition and ventilate spaces to settings that do not necessarily support occupants and their activities. In response to this, we investigate indoor air quality, as influenced by building ventilation and occupancy, and indoor thermal conditions, as influenced by space conditioning, as two main indoor exposures that are influenced by these systems and also impact occupant health. We then assessed occupant cognitive performance and perceptions of the indoor environment with participant test and survey responses collected through our smartphone-based research application. We used this acute exposure and outcome data to model associations between indoor air and thermal conditions and metrics of cognitive function and thermal sensation. Collectively, the model estimates show that lower carbon dioxide concentrations, achieved through higher outdoor ventilation, are consistently and significantly associated with improved cognitive test scores. For thermal conditions, we observe that a normative range of roughly 22-26 ⁰C can support cognitive performance and thermal sensation in a variety of settings and that temperatures above and below this range show evidence of decreasing cognitive test scores. The relationship between indoor air moisture and cognitive performance is less clear from this work. There is preliminary evidence that common thermal modeling approaches, such as the use of temperature and relative humidity as separate thermal variables or the use of pervasively used thermal comfort models, might underestimate the potential importance of indoor moisture with respect to occupant outcomes. We explore enthalpy as a potentially useful combined temperature and moisture metric and observe preliminary evidence of consistent associations between higher values of indoor enthalpy, up to approximately 55 kJ/kg, and improved cognitive test scores. Additional research is needed to understand how these associations might vary in wider exposure ranges, across different built environment settings and populations, and the potential implications for building energy expenditure. Overall, these collective results suggest that focusing on increasing outdoor air ventilation and maintaining temperatures within a normative range of approximately 22-26 °C, can support occupants and their activities in working and learning environments
“Children Will Listen”: an exploration on Judaism, motherhood, and stereotype in Stephen Sondheim’s Into the Woods
No full textThis thesis explores the interplay between themes of motherhood, stereotype, and Judaism in one of Stephen Sondheim’s most famous and most often-performed musicals, Into the Woods. It endeavors to prove that the some of the characters in Into the Woods are coded as stereotypical Jewish Mothers, as seen on television, in movies, in books, and other forms of popular culture. This coding allows audience members to engage with a character that may feel familiar to them, but, like his use of popular fairy tales in Into the Woods, Sondheim's portrayal of a well-known stereotype complicates an audience’s typical understanding of what it means. Exploration into relevant historical background of the history of Judaism in musical theatre, Stephen Sondheim’s life and upbringing, and the Jewish Mother stereotype all provide an entry point into how these topics play together. Historical background and thorough analysis of some of the female characters in Into the Woods reveal the ways in which the Jewish Mother stereotype is evident throughout the musical and offer insight into the broader importance of subversion of these stereotypes
An antiferromagnetic diode effect in even-layered MnBi2Te4
No full textIn a PN junction, the separation between positive and negative charges leads to diode transport. In the past few years, the intrinsic diode transport in noncentrosymmetric polar conductors has attracted great interest, because it suggests novel nonlinear applications and provides a symmetry-sensitive probe of Fermi surface. Recently, such studies have been extended to noncentrosymmetric superconductors, realizing the superconducting diode effect. Here, we show that, even in a centrosymmetric crystal without directional charge separation, the spins of an antiferromagnet (AFM) can generate a spatial directionality, leading to an AFM diode effect. We observe large second-harmonic transport in a nonlinear electronic device enabled by the compensated AFM state of even-layered MnBiTe. We also report a novel electrical sum-frequency generation (SFG), which has been rarely explored in contrast to the well-known optical SFG in wide-gap insulators. We demonstrate that the AFM enables an in-plane field-effect transistor and harvesting of wireless electromagnetic energy. The electrical SFG establishes a powerful method to study nonlinear electronics built by quantum materials. The AFM diode effect paves the way for potential device concepts including AFM logic circuits, self-powered AFM spintronics and other applications that potentially bridge nonlinear electronics with AFM spintronics.Accepted Manuscrip
Citizens of Nowhere: Stateless and Refugee Literature in Latin America
No full textThis work analyzes a transmedial and transnational constellation of primarily literary texts (poetry, fiction, prose, and art) created predominantly by Latin American writers, artists, and intellectuals concerning the refugees fleeing World War II. Its main claim is that, through their works, a series of Latin American authors and artists (Gabriela Mistral, Lasar Segall, Victoria Ocampo, Pablo Neruda, and João Guimarães Rosa) articulated the cultural, historicopolitical, and ethical implications of the emergence and spread of statelessness in the world and participated in the articulation of a new set of cosmopolitan set of rights in the aftermath of World War II. More broadly, it analyzes how literature (and aesthetic form, broadly conceived), and particularly Latin American literature and art, documented and worked through the creation of a new historical subject in modernity —the stateless person— and intervened in the articulation of the human rights agenda promoted by the United Nations during the postwar era. Its approach is informed by archival research, in dialogue with theoretical conceptualizations of statelessness’ legal and political consequences and tackled through a comparative and transatlantic perspective that studies works by refugee writers who found asylum in Latin America during the war; specifically, Austrian Jewish writer Stefan Zweig. Additionally, it draws on contemporary experiences and crises of forced displacement by examining works such as art by Brazilian artist and poet Leila Danziger and fiction by Argentinian-Peruvian-Spanish writer Miguel Enesco
Understanding the Health Care Delivery System: Empirical Investigations of Insurer Site of Care Policies and Physician Competencies
No full textIn the United States, the path from having a medical condition to receiving medical care for that condition is a multistep process involving multiple stakeholders and professionals. In particular, for the vast majority of the age under-65 population in the United States, patients will need to interact with both a physician and a commercial health insurer. The role of the physician has always been central in determining the care that a patient will receive. What is less clear, however, is how variation in competency among physicians is related to the care that patients receive, and from whom patients receive it. Conversely, in the last few decades the role of health insurers has shifted from one of primarily being aggregators of risk and ex-post indemnifiers to having a more direct impact on medical care through utilization management policies.
In Chapter 1, I, along with collaborators Alton Lu, Yanchun Xu, and Russ Michael, investigate a particular type of utilization management policy among commercial health insurers. These policies set out to shift the site of care of administration of physician administered drugs from the hospital outpatient department (HOPD) to other, less expensive sites of care (Site of Care policies). We are able to extract the timing of these policies for specific drugs from insurers’ publicly-available medical policies, and then link exposure to these policies to individual insurance claims with a data set from Blue Health Intelligence. Using a staggered difference in difference design, we show that Site of Care policies lead to a shift of approximately 4.5 percentage points of physician administered drug claims, or 22% of HOPD physician administered drug claims, from the HOPD to other sites of care by two years after policy implementation. We also estimate that these policies lead to an approximately 7.0 % relative reduction in spending by two years after policy implementation, and that this point estimate may be best interpreted as a lower bound on (the point-estimate for) savings.
In Chapter 2, I, along with Sean Hogan, Eric Holmboe, J. Michael McWilliams, and Michael Chernew, investigate different ways of identifying low-performing internal medicine physicians using the Accreditation Council for Graduate Medical Education Internal Medicine Milestone Scores. We first show that identifying low-performing doctors is a useful first step in estimating the relationship between utilization and physician ability. We then show how differences in grading can affect the identification of low performers in the ACGME data. Finally, we use this intuition to construct a highly specific measure of low performance.
In Chapter 3, I, again with Sean Hogan, Eric Holmboe, J. Michael McWilliams, and Michael Chernew, examine the relationship between comparative advantage and fellowship choice in Orthopedic Surgery. By using the uniquely specific ACGME Milestones for Orthopedic Surgery, we show that comparative advantage in the final two years of residency consistently predicts sub-specialty choice, with suggestive evidence as early as the middle of the third year. We discuss multiple interpretations of this result, and the potential implications for policy makers
Genomic data in the All of Us Research Program
No full textComprehensively mapping the genetic basis of human disease across diverse individuals is a longstanding goal for the field of human genetics.1-4 The All of Us Research Program is a longitudinal cohort aiming to enroll a diverse group of at least one million individuals across the United States to accelerate biomedical research and improve human health.5,6 Here we describe the program’s genomics data release of 245,388 clinical grade genome sequences. This resource is unique in its diversity as 77% of participants are from communities historically underrepresented in biomedical research and 46% are individuals from underrepresented racial and ethnic minorities. All of Us identified >1 billion genetic variants, including >151 million previously unreported genetic variants, >1.8 million of which had coding consequences. Leveraging linkage between genomic data and the longitudinal electronic health record, we evaluated 3,724 genetic variants associated with 117 diseases and found high replication rates across both European and African ancestry participants. Summary level data are publicly available, and individual-level data can be accessed by researchers through the All of Us Researcher Workbench via a unique data passport model with a median time from initial researcher registration to data access of 29 hours. We anticipate that this diverse dataset will advance the promise of genomic medicine for all.Version of Recor
Threat processing via the septohippocampal system
No full textIn the face of danger, animals must quickly detect and process environmental stimuli to produce appropriate behavioral responses. Moreover, internal states both tune animal behavior and change in response to external stimuli. These behavioral states are dynamic and permit animals to efficiently transition between behaviors that are appropriate to any given situation. For example, when an animal is presented with an unexpected threat, the animal may quickly switch from an offline, quiescent state to an aroused, hypervigilant state – this transition is necessary for the survival of the animal. However, excessive hypervigilance can be maladaptive and is a common diagnostic marker of various human mental illnesses.
The septohippocampal system, composed of the septum and the hippocampus, has previously been implicated in regulating behavioral responses to external sensory stimuli and in modulating affective components of behavior. Yet little is understood on how the septohippocampal system integrates threat-related sensory information to guide appropriate defensive behaviors. In this work, we leverage a subpopulation of Lateral Septum (LS) neurons labeled by the type 2 corticotropin-releasing hormone receptor (LSCrhr2) as a genetic entry point into the septohippocampal system. Here, we demonstrate that 1) LSCrhr2 neurons bidirectionally modulate stimulus-evoked defensive behaviors, 2) LSCrhr2 neurons promote physiological changes in arousal and 3) LSCrhr2 neurons are polysynaptically connected with higher-order cortical brain regions. Additionally, we find evidence that upstream hippocampal projection neurons correlate with physiological arousal and partially respond to threat-related sensory stimuli. These data place the septohippocampal system as a node that controls stimulus-evoked defensive behaviors potentially through its indirect connectivity with the cortex.Medical SciencesMedical Science
Clinical impact of preemptive pharmacogenomic testing on antiplatelet therapy in a real-world setting
No full textCYP2C19 genotyping to guide antiplatelet therapy after patients develop acute coronary syndromes (ACS) or require percutaneous coronary interventions (PCIs) reduces the likelihood of major adverse cardiovascular events (MACE). Evidence about the impact of preemptive testing, where genotyping occurs while patients are healthy, is lacking. In patients initiating antiplatelet therapy for ACS or PCI, we compared medical records data from 67 patients who received CYP2C19 genotyping preemptively (results >7 days before need) against medical records data from 67 propensity score-matched patients who received early genotyping (results within 7 days of need). We also examined data from 141 patients who received late genotyping (results >7 days after need). We compared the impact of genotyping approaches on medication selections, specialty visits, MACE and bleeding events over one year. Patients with CYP2C19 loss-of-function alleles were less likely to be initiated on clopidogrel if they received preemptive rather than early or late genotyping (18.2%, 66.7%, and 73.2% respectively, p=0.001). No differences were observed by genotyping approach in the number of specialty visits or likelihood of MACE or bleeding events (all p>0.21). Preemptive genotyping had a strong impact on initial antiplatelet selection and a comparable impact on patient outcomes and healthcare utilization, compared to genotyping ordered after a need for antiplatelet therapy had been identified.Accepted Manuscrip
Using Models to Persuade
No full textWe present a framework where “model persuaders” influence receivers’ beliefs by proposing models that organize past data to make predictions. Receivers are assumed to find models more compelling when they better explain the data, fixing receivers’ prior beliefs. Model persuaders face a trade-off: better-fitting models induce less movement in receivers’ beliefs. Consequently, a receiver exposed to the true model can be most misled by persuasion when that model fits poorly, competition between persuaders tends to neutralize the data by pushing toward better-fitting models, and a persuader facing multiple receivers is more effective when he can send tailored, private messages.Author's Origina
Mechanical and Electrical Design for Shape-Morphing Soft Actuators
No full textThe need for soft, flexible devices capable of large deformations is evident in a variety of areas including soft robotics, haptics, and wearable devices. Although numerous approaches exist for creating these soft devices, considerable interest has surrounded dielectric elastomer actuators (DEAs). DEAs are electrically controlled actuators with quick, reversible deformation. DEAs are often referred to as “artificial muscles” because their energy density and achievable strains are comparable to mammalian muscles. This thesis focuses on advancing DEAs and DEA technology to improve their capabilities and explore further shape-morphing applications.
An optically reconfigurable electrode structure is proposed for use in DEAs and other similar soft actuators. As opposed to a traditional parallel plate capacitor electrode structure, two sets of non-overlapping conductive carbon nanotube stripes are connected to sheets of photoconductive zinc oxide in order to create light-responsive actuators. Precise, reconfigurable control over DEA actuation through UV illumination is demonstrated. A variation of this design is explored to create a dynamic surface for object manipulation via electroadhesion, in which UV illumination is used to activate electrode stripes off-centered from a cylinder to produce rotary motion and translation of the cylinder. An entirely soft pump system is fabricated using a shape-morphing DEA design and a soft Tesla valve structure. The system is used to pump air and water, with potential utility in a range of applications including wearable pneumatic and hydraulic actuators. Finally, an array of shape-morphing DEAs is used to create a bioinspired squid fin