38 research outputs found

    Active Camera Stabilization from High Altitude Balloons

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    Many applications of High Altitude Ballooning (HAB) require maintaining a bearing in a non-inertial frame of reference, for example keeping a camera continuously pointed at the sun from a HAB payload in motion. Maintaining a consistent bearing is especially difficult on a HAB flight because it is hard to accurately measure and compensate the relative motion of the payload. In addition, friction, conservation of angular momentum, and errors in relative bearing measurement complicate the solution. This project aims to solve these issues using a combination of accelerometer data, gyro data, and a stepper motor-driven platform. It was launched as part of the Far Horizons project at the Adler Planetarium, whose mission is bringing real space exploration down to Earth and into the hands of students, volunteers, and the public. The initial design was built for use in the 2017 Eclipse mission, but will be also be used in missions such as mapping light pollution from a HAB platform. The system expands capabilities of general HAB missions and can be open-sourced to provide the HAB community with a solution to a unique problem in High Altitude Ballooning

    A Formal Privacy Framework for Partially Private Data

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    Despite its many useful theoretical properties, differential privacy (DP) has one substantial blind spot: any release that non-trivially depends on confidential data without additional privacy-preserving randomization fails to satisfy DP. Such a restriction is rarely met in practice, as most data releases under DP are actually "partially private" data (PPD). This poses a significant barrier to accounting for privacy risk and utility under logistical constraints imposed on data curators, especially those working with official statistics. In this paper, we propose a privacy definition which accommodates PPD and prove it maintains similar properties to standard DP. We derive optimal transport-based mechanisms for releasing PPD that satisfy our definition and algorithms for valid statistical inference using PPD, demonstrating their improved performance over post-processing methods. Finally, we apply these methods to a case study on US Census and CDC PPD to investigate private COVID-19 infection rates. In doing so, we show how data curators can use our framework to overcome barriers to operationalizing formal privacy while providing more transparency and accountability to users.Comment: 31 pages, 7 figure

    Privately Answering Queries on Skewed Data via Per Record Differential Privacy

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    We consider the problem of the private release of statistics (like aggregate payrolls) where it is critical to preserve the contribution made by a small number of outlying large entities. We propose a privacy formalism, per-record zero concentrated differential privacy (PzCDP), where the privacy loss associated with each record is a public function of that record's value. Unlike other formalisms which provide different privacy losses to different records, PzCDP's privacy loss depends explicitly on the confidential data. We define our formalism, derive its properties, and propose mechanisms which satisfy PzCDP that are uniquely suited to publishing skewed or heavy-tailed statistics, where a small number of records contribute substantially to query answers. This targeted relaxation helps overcome the difficulties of applying standard DP to these data products.Comment: 14 pages, 5 figure

    Between Privacy and Utility: On Differential Privacy in Theory and Practice

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    Differential privacy (DP) aims to confer data processing systems with inherent privacy guarantees, offering strong protections for personal data. But DP’s approach to privacy carries with it certain assumptions about how mathematical abstractions will be translated into real-world systems, which—if left unexamined and unrealized in practice—could function to shield data collectors from liability and criticism, rather than substantively protect data subjects from privacy harms. This article investigates these assumptions and discusses their implications for using DP to govern data-driven systems. In Parts 1 and 2, we introduce DP as, on one hand, a mathematical framework and, on the other hand, a kind of real-world sociotechnical system, using a hypothetical case study to illustrate how the two can diverge. In Parts 3 and 4, we discuss the way DP frames privacy loss, data processing interventions, and data subject participation, arguing it could exacerbate existing problems in privacy regulation. In part 5, we conclude with a discussion of DP’s potential interactions with the endogeneity of privacy law, and we propose principles for best governing DP systems. In making such assumptions and their consequences explicit, we hope to help DP succeed at realizing its promise for better substantive privacy protections

    Low ι2β1 Integrin Function Enhances the Proliferation of Fibroblasts from Patients with Idiopathic Pulmonary Fibrosis by Activation of the β-Catenin Pathway

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    Idiopathic pulmonary fibrosis (IPF) is a progressive and incurable fibroproliferative disorder characterized by unrelenting proliferation of fibroblasts and their deposition of collagen within alveoli, resulting in permanently scarred, nonfunctional airspaces. Normally, polymerized collagen suppresses fibroblast proliferation and serves as a physiological restraint to limit fibroproliferation after tissue injury. The IPF fibroblast, however, is a pathologically altered cell that has acquired the capacity to elude the proliferation-suppressive effects of polymerized collagen. The mechanism for this phenomenon remains incompletely understood. Here, we demonstrate that expression of ι2β1 integrin, a major collagen receptor, is pathologically low in IPF fibroblasts interacting with polymerized collagen. Low integrin expression in IPF fibroblasts is associated with a failure to induce PP2A phosphatase activity, resulting in abnormally high levels of phosphorylated (inactive) GSK-3β and high levels of active β-catenin in the nucleus. Knockdown of β-catenin in IPF fibroblasts inhibits their ability to proliferate on collagen. Interdiction of ι2β1 integrin in control fibroblasts reproduces the IPF phenotype and leads to the inability of these cells to activate PP2A, resulting in high levels of phosphorylated GSK-3β and active β-catenin and in enhanced proliferation on collagen. Our findings indicate that the IPF fibroblast phenotype is characterized by low ι2β1 integrin expression, resulting in a failure of integrin to activate PP2A phosphatase, which permits inappropriate activation of the β-catenin pathway

    Impact of Experience Corps® Participation on Children’s Academic Achievement and School Behavior

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    This article reports on the impact of the Experience Corps® (EC) Baltimore program, an intergenerational, school-based program aimed at improving academic achievement and reducing disruptive school behavior in urban, elementary school students in Kindergarten through third grade (K-3). Teams of adult volunteers aged 60 and older were placed in public schools, serving 15 h or more per week, to perform meaningful and important roles to improve the educational outcomes of children and the health and well-being of volunteers. Findings indicate no significant impact of the EC program on standardized reading or mathematical achievement test scores among children in grades 1–3 exposed to the program. K-1st grade students in EC schools had fewer principal office referrals compared to K-1st grade students in matched control schools during their second year in the EC program; second graders in EC schools had fewer suspensions and expulsions than second graders in non-EC schools during their first year in the EC program. In general, both boys and girls appeared to benefit from the EC program in school behavior. The results suggest that a volunteer engagement program for older adults can be modestly effective for improving selective aspects of classroom behavior among elementary school students in under-resourced, urban schools, but there were no significant improvements in academic achievement. More work is needed to identify individual- and school-level factors that may help account for these results

    Structure–activity study of N-((trans)-4-(2-(7-cyano-3,4-dihydroisoquinolin-2(1H)-yl)ethyl)cyclohexyl)-1H-indole-2-carboxamide (SB269652), a bitopic ligand that acts as a negative allosteric modulator of the dopamine D2 receptor

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    We recently demonstrated that SB269652 (1) engages one protomer of a dopamine D2 receptor (D2R) dimer in a bitopic mode to allosterically inhibit the binding of dopamine at the other protomer. Herein, we investigate structural deter- minants for allostery, focusing on modifications to three moieties within 1. We find that orthosteric “head” groups with small 7-substituents were important to maintain the limited negative cooperativity of analogues of 1, and replacement of the tetrahydroisoquinoline head group with other D2R “privileged structures” generated orthosteric antagonists. Additionally, replacement of the cyclohexylene linker with polymethylene chains conferred linker length dependency in allosteric pharma- cology. We validated the importance of the indolic NH as a hydrogen bond donor moiety for maintaining allostery. Replacement of the indole ring with azaindole conferred a 30-fold increase in affinity while maintaining negative cooperativity. Combined, these results provide novel SAR insight for bitopic ligands that act as negative allosteric modulators of the D2R
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