Simulating Star Formation and Feedback in Galactic Disk Models

We use a high-resolution grid-based hydrodynamics method to simulate the multi-phase interstellar medium in a Milky Way-size quiescent disk galaxy. The models are global and three-dimensional, and include a treatment of star formation and feedback. We examine the formation of gravitational instabilities and show that a form of the Toomre instability criterion can successfully predict where star formation will occur. Two common prescriptions for star formation are investigated. The first is based on cosmological simulations and has a relatively low threshold for star formation, but also enforces a comparatively low efficiency. The second only permits star formation above a number density of 1000 cm^-3 but adopts a high efficiency. We show that both methods can reproduce the observed slope of the relationship between star formation and gas surface density (although at too high a rate for our adopted parameters). A run which includes feedback from type II supernovae is successful at driving gas out of the plane, most of which falls back onto the disk. This feedback also substantially reduces the star formation rate. Finally, we examine the density and pressure distribution of the ISM, and show that there is a rough pressure equilibrium in the disk, but with a wide range of pressures at a given location (and even wider for the case including feedbackComment: 14 pages, 12 figures, accepted to Astrophysical Journa

Re-Envisioning Professional Education

In the dynamic, hyper-connected, and unpredictable 21st century, workplace and career paradigms are rapidly changing. The professions are no exception. Technology has routinized and increased access to the expertise that traditionally set professionals apart from other workers, leading some to forecast professions’ demise. Even if, as we suspect, new forms of complexity and needs for expertise continue to outrun technology, professionals’ lives and careers will diverge dramatically from past norms. In the world we anticipate, the number of theories, diagnoses, and strategies among which each professional — alone or in teams — must make informed and workable judgments will increase exponentially, as will the rapidity with which their specialties become obsolete and have to be retooled or replaced. In this world, learning to learn will far outstrip the importance of applying the specialized knowledge with which professionals are initially programmed. If this prediction is correct, then university-based professional schools (hereinafter “professional schools”), which historically have done that initial programming, must change at the same pace as their graduates’ careers. Evidence that professional schools are not evolving quickly enough is widespread. Employers and policymakers criticize professional schools for not preparing graduates to succeed in the modern workplace or to solve increasingly acute public problems. And prospective students are voting with their feet, opting for less expensive and more relevant training from accelerators, boot camps, and massive open online courses (MOOCs) and in dynamic work environments themselves. In order to help the professions retool for the modern world, professional education must retool itself

Out of Class and Off Track: High School Suspension in New York City

Research suggests that suspensions are detrimental to students' socio-emotional and academic development and to the likelihood that they graduate from high school. This literature often describes the types of students who are suspended or the relationships between suspension and student outcomes, either through qualitative methods or quantitative methods that fail to adequately account for the differences between students who are and are not suspended. Using longitudinal administrative data from New York City, I build upon extant research by estimating the link between suspension and short-term academic outcomes within a student fixed effects framework. This approach eliminates unmeasured differences across students that are associated with both the likelihood of being suspended and important student outcomes. I then estimate the link between suspension and long-term academic outcomes using propensity score matching. I find that suspension is associated with increased absences and latenesses, and a decreased likelihood of passing courses the term in which the suspension occurred. Furthermore, suspension is associated with a lower likelihood of graduating within four, five, or six years, and a decreased likelihood of passing Regents exams

Concert recording 2016-11-09

[Tracks 1-3]. Sonata for piano and violin no. 1 in G major, op. 78 / Johannes Brahms -- [Track 4]. Selections from Dichterliebe, op. 48. Im wunderschönen Monat Mai [Track 5]. Aus meinen Tränen sprießen [Track 6]. Die Rose, die Lilie, die Taube, die Sonne [Track 7]. Ich will meine Seele tauchen [Track 8]. Im Rhein, im heiligen Strome [Track 9]. Ich grolle nicht [Track 10]. Das ist ein Flöten und Geigen [Track 11]. Am leuchtenden Sommermorgen [Track 12]. Ich hab\u27 im Traum geweinet [Track 13]. Aus alten Märchen winkt es / Robert Schumann -- [Track 14-16]. Sonata for clarinet and piano / Francis Poulenc

Curriculum-Based Professional Learning: The State of the Field

In recent years, open-source, high-quality instructional materials (HQIM) have presented exciting opportunities to enhance students' engagement and agency in their learning, expand access to grade-level content, and narrow the boundaries between home and school. However, research suggests that curricula, on their own, can only do so much to advance student learning; curriculum-based professional learning is an essential ingredient. Yet, to build the field of curriculum-based professional learning, a field of diverse, interdisciplinary actors from across the education sector must work together to collectively co-produce improved professional learning that strengthens educational experiences and outcomes for students. With support from the Carnegie Corporation of New York, Columbia University's Center for Public Research and Leadership (CPRL) researched the state of the field of curriculum-based professional learning, identifying its areas of strength and opportunities to grow, scale, and strengthen the effort. Building on an analysis of information provided by 146 people over the course of 122 interviews, as well as an extensive review of secondary sources, the research reveals that the field of curriculum-based professional learning is emerging. While its impact is not yet consistently felt across the education ecosystem, its infrastructure and field-level agenda are fairly well-developed. Its actors, knowledge base, and resources are still in more nascent stages and require focused attention for the field to reach its potential for impact

Family Moves and the Future of Public Education

State laws compel school-aged children to attend school while fully funding only public schools. Especially following the COVID-19 pandemic, this arrangement is under attack — from some for unconstitutionally coercing families to expose their children to non-neutral values to which they object and from others for ignoring the developmental needs of students, particularly students of color and in poverty whom public schools have long underserved. This Article argues that fully subsidized public education is constitutional as long as public schools fulfill their mission to model and commit people to liberal democratic values of tolerance and respect for all persons as equal choosers. To be sure, those values are not neutral. But as Brown v. Board famously concluded, their promotion in public schools is perhaps the nation’s and states’ single most compelling interest, because it is essential to the ability of people with diverse beliefs to live together harmoniously while preserving their vast freedoms in other respects. To keep public education from qualifying those freedoms any more than necessary, states give families a right to opt for private education, but at their own expense. This arrangement serves the compelling interest in public education, however, only if public schools — bolstered by compulsory education laws and their uniquely full public subsidization — attract enough families. For well over a century, public schools have attracted around 90% of all school children. Today, however, family moves away from public education are eroding its ability to attract children due principally to public education’s conflation of “public” with bureaucratically “uniform” education — precluding pedagogically, democratically, and equitably essential differentiation among students. The Article proposes ways public schools can better model liberal democratic values by engaging all families in the cooperative and differentiated direction of their children’s learning

A Bayesian approach to estimating causal vaccine effects on binary post-infection outcomes

To estimate causal effects of vaccine on post-infection outcomes, Hudgens and Halloran (2006) defined a post-infection causal vaccine efficacy estimand VEI based on the principal stratification framework. They also derived closed forms for the maximum likelihood estimators (MLEs) of the causal estimand under some assumptions. Extending their research, we propose a Bayesian approach to estimating the causal vaccine effects on binary post-infection outcomes. The identifiability of the causal vaccine effect VEI is discussed under different assumptions on selection bias. The performance of the proposed Bayesian method is compared with the maximum likelihood method through simulation studies and two case studies — a clinical trial of a rotavirus vaccine candidate and a field study of pertussis vaccination. For both case studies, the Bayesian approach provided similar inference as the frequentist analysis. However, simulation studies with small sample sizes suggest that the Bayesian approach provides smaller bias and shorter confidence interval length