Privacy-Preserving Patient Similarity Learning in a Federated Environment: Development and Analysis

Background: There is an urgent need for the development of global analytic frameworks that can perform analyses in a privacy-preserving federated environment across multiple institutions without privacy leakage. A few studies on the topic of federated medical analysis have been conducted recently with the focus on several algorithms. However, none of them have solved similar patient matching, which is useful for applications such as cohort construction for cross-institution observational studies, disease surveillance, and clinical trials recruitment. Objective: The aim of this study was to present a privacy-preserving platform in a federated setting for patient similarity learning across institutions. Without sharing patient-level information, our model can find similar patients from one hospital to another. Methods: We proposed a federated patient hashing framework and developed a novel algorithm to learn context-specific hash codes to represent patients across institutions. The similarities between patients can be efficiently computed using the resulting hash codes of corresponding patients. To avoid security attack from reverse engineering on the model, we applied homomorphic encryption to patient similarity search in a federated setting. Results: We used sequential medical events extracted from the Multiparameter Intelligent Monitoring in Intensive Care-III database to evaluate the proposed algorithm in predicting the incidence of five diseases independently. Our algorithm achieved averaged area under the curves of 0.9154 and 0.8012 with balanced and imbalanced data, respectively, in ??-nearest neighbor with ??=3. We also confirmed privacy preservation in similarity search by using homomorphic encryption. Conclusions: The proposed algorithm can help search similar patients across institutions effectively to support federated data analysis in a privacy-preserving manner

The political import of deconstruction—Derrida’s limits?: a forum on Jacques Derrida’s specters of Marx after 25 Years, part I

Jacques Derrida delivered the basis of The Specters of Marx: The State of the Debt, the Work of Mourning, & the New International as a plenary address at the conference ‘Whither Marxism?’ hosted by the University of California, Riverside, in 1993. The longer book version was published in French the same year and appeared in English and Portuguese the following year. In the decade after the publication of Specters, Derrida’s analyses provoked a large critical literature and invited both consternation and celebration by figures such as Antonio Negri, Wendy Brown and Frederic Jameson. This forum seeks to stimulate new reflections on Derrida, deconstruction and Specters of Marx by considering how the futures past announced by the book have fared after an eventful quarter century. Maja Zehfuss, Antonio Vázquez-Arroyo and Dan Bulley and Bal Sokhi-Bulley offer sharp, occasionally exasperated, meditations on the political import of deconstruction and the limits of Derrida’s diagnoses in Specters of Marx but also identify possible paths forward for a global politics taking inspiration in Derrida’s work of the 1990s

Chronology of tectonic, geomorphic, and volcanic interactions and the tempo of fault slip near Little Lake, California

New geochronologic and geomorphic constraints on the Little Lake fault in the Eastern California shear zone reveal steady, modest rates of dextral slip during and since the midto- late Pleistocene. We focus on a suite of offset fl uvial landforms in the Pleistocene Owens River channel that formed in response to peri odic interaction with nearby basalt fl ows, thereby recording displacement over multiple time intervals. Overlap between 40Ar/39Ar ages for the youngest intracanyon basalt fl ow and 10Be surface exposure dating of downstream terrace surfaces suggests widespread channel incision during a prominent outburst fl ood through the Little Lake channel at ca. 64 ka. Older basalt fl ows fl anking the upper and lower canyon margins indicate localization of the Owens River in its current position between 212 ± 14 and 197 ± 11 ka. Coupled with terrestrial light detection and ranging (lidar) and digital topographic measurements of dextral offset, the revised Little Lake chronology indicates average dextral slip rates of at least ~0.6–0.7 mm/yr and <1.3 mm/yr over intervals ranging from ~104 to 105 yr. Despite previous geodetic observations of relatively rapid interseismic strain along the Little Lake fault, we fi nd no evidence for sustained temporal fl uctuations in slip rates over multiple earthquake cycles. Instead, our results indicate that accelerated fault loading may be transient over much shorter periods (~101 yr) and perhaps indicative of time-dependent seismic hazard associated with Eastern California shear zone faults

Performance of reinforced concrete structures subjected to fire following earthquake

Fire following earthquake (FFE) is a serious threat to structures that are partially damaged in a prior earthquake potentially leading to a quick collapse of the structure. The majority of standards and codes for the design of structures against earthquake, however, ignore the possibility of FFE and thus buildings designed with those codes fail swiftly when exposed to fire after earthquake. A sequential structural analysis based on FEMA 356 is performed here on the Immediate Occupancy (IO) and the Life Safety (LS) performance levels of two reinforced concrete frames. The frames are first subjected to an earthquake load with a Peak Ground Acceleration (PGA) of.30 g. This is followed by a fire analysis, using ISO 834 and natural fire curves. The time taken for the structures weakened by the earthquake to collapse under these fires is then found through a robust numerical analysis. As a benchmark, fire-only analyses are also performed for undamaged structures. The results show that earthquake-weakened structures are more vulnerable to fire than undamaged structures, to the extent that the fire resistance of the damaged structures can decline to about a third of the original undamaged structures. The results also show that the fire resistance of the frame exposed to the natural fire differs from that of the frame exposed to the ISO 834 fire. This is due to the inclusion of parameters such as dimensions of the compartment as well as thermal properties of the combustible materials and the size and position of opening in the natural fire model, which does not exist in the ISO 834. Whilst the investigation is conducted for a certain class of structures (regular buildings, reinforced concrete frames, 3 stories), the results confirm the need for the incorporation of FFE into the process of analysis and design, and provides some quantitative measures on the level of associated effects