An ACL2 Mechanization of an Axiomatic Framework for Weak Memory

Proving the correctness of programs written for multiple processors is a challenging problem, due in no small part to the weaker memory guarantees afforded by most modern architectures. In particular, the existence of store buffers means that the programmer can no longer assume that writes to different locations become visible to all processors in the same order. However, all practical architectures do provide a collection of weaker guarantees about memory consistency across processors, which enable the programmer to write provably correct programs in spite of a lack of full sequential consistency. In this work, we present a mechanization in the ACL2 theorem prover of an axiomatic weak memory model (introduced by Alglave et al.). In the process, we provide a new proof of an established theorem involving these axioms.Comment: In Proceedings ACL2 2014, arXiv:1406.123

Polymorphic Types in ACL2

This paper describes a tool suite for the ACL2 programming language which incorporates certain ideas from the Hindley-Milner paradigm of functional programming (as exemplified in popular languages like ML and Haskell), including a "typed" style of programming with the ability to define polymorphic types. These ideas are introduced via macros into the language of ACL2, taking advantage of ACL2's guard-checking mechanism to perform type checking on both function definitions and theorems. Finally, we discuss how these macros were used to implement features of Specware, a software specification and implementation system.Comment: In Proceedings ACL2 2014, arXiv:1406.123

Why do Healthcare Organizations Choose to Violate Information Technology Privacy Regulations? Proposing the Selective Information Privacy Violations in Healthcare Organizations Model (SIPVHOM)

Privacy concerns about protected healthcare information (PHI) are rampant because of the ease of access to PHI from the advent of Healthcare IT (HIT) and its exploding use. Continual negative cases in the popular attest to the fact that current privacy regulations are failing to keep PHI sufficiently secure in the climate of increate HIT use. To address these issues, this paper proposes a theoretical model with testable hypotheses to explain and predict organizational IT privacy violations in the healthcare industry. Our model, the Selective Information Privacy Violations in Healthcare Organizations Model (SIPVHOM), explains how organizational structures and processes and characteristics of regulatory environments alter perceptions of risk and thereby the likelihood of rule violations. Finally, based on SIPVHOM, we offer recommendations for the structuring of regulatory environments and organizational structures to decrease abuse of PHI

Constitutivism

A brief explanation and overview of constitutivism

Philosophy of action

The philosophical study of human action begins with Plato and Aristotle. Their influence in late antiquity and the Middle Ages yielded sophisticated theories of action and motivation, notably in the works of Augustine and Aquinas.1 But the ideas that were dominant in 1945 have their roots in the early modern period, when advances in physics and mathematics reshaped philosophy

Characters of Combinatorial Hopf Algebras

This project is concerned with the use of Hopf algebras to study combinatorial questions about graphs and posets. We discuss Stanley\u27s connection between the chromatic polynomial of a graph G and the acyclic orientations of G. We then recast Stanley\u27s result using the language of Hopf algebras, and this correspondence is described in terms of inverting a character. Applying this Hopf algebraic machinery to posets, we explore a character-theoretic approach to studying the enumeration of order-preserving maps. We use this machinery to derive an algebraic proof of a reciprocity theorem relating strict to weak order-preserving maps. Moreover, we give a new proof of Stanley\u27s graph theory result. Finally, we create a new Hopf algebra of acyclically oriented graphs, and use it to summarize the connection between graphs and posets

Sociodemographic and clinical factors associated with receipt of biomarker testing in patients with metastatic colorectal cancer

Abstract Background Standard clinical practice and national guidelines dictate somatic testing of metastatic colorectal cancer (mCRC) tumors to guide appropriate therapy; however, previous studies suggest that not all patients are tested. The objective of this study was to investigate potential differences in testing for mCRC by demographic and clinical factors. Methods We performed a retrospective review of de‐identified patient data derived from electronic health records (EHRs) of 25,469 patients diagnosed with mCRC between the years 2013 and 2020. Our outcome was a receipt of the following tests: (a) biomarker testing (BRAF, KRAS, NRAS, MMR/MSI) and (b) next‐generation sequencing (NGS). We interrogated our data using the machine‐learning algorithm Classification and Regression Tree (CART), a unique approach to identifying combinations of, rather than individual demographic and clinical characteristics associated with receipt of testing. Results A total of 25,469 patients were identified with mCRC. Of these, 21,133 (83%) received either biomarker testing only (n = 12,485) or any testing (biomarker + NGS) (n = 8648). The proportion of patients who received any testing increased over calendar time for all age, race, and sex categories. Receipt of any testing was highest (90%) among younger and patients with better performance status, and there was no difference in receipt of any testing by race. The highest percentage of NGS testing was among those with better performance status, <70 years old, commercial or other governmental program payers, and low comorbidity burden; however, those who were Black or Hispanic had a lower prevalence of NGS testing than those who were White. Conclusions and Relevance Considerable variations exist in somatic biomarker testing across subgroups of the population. Identification of genomic alterations can aid in determining targeted treatment and improving clinical outcomes; therefore, equitable use of these testing strategies, particularly NGS, is necessary