Distributed Computability in Byzantine Asynchronous Systems

In this work, we extend the topology-based approach for characterizing computability in asynchronous crash-failure distributed systems to asynchronous Byzantine systems. We give the first theorem with necessary and sufficient conditions to solve arbitrary tasks in asynchronous Byzantine systems where an adversary chooses faulty processes. In our adversarial formulation, outputs of non-faulty processes are constrained in terms of inputs of non-faulty processes only. For colorless tasks, an important subclass of distributed problems, the general result reduces to an elegant model that effectively captures the relation between the number of processes, the number of failures, as well as the topological structure of the task's simplicial complexes.Comment: Will appear at the Proceedings of the 46th Annual Symposium on the Theory of Computing, STOC 201

Networked Restless Bandits with Positive Externalities

Restless multi-armed bandits are often used to model budget-constrained resource allocation tasks where receipt of the resource is associated with an increased probability of a favorable state transition. Prior work assumes that individual arms only benefit if they receive the resource directly. However, many allocation tasks occur within communities and can be characterized by positive externalities that allow arms to derive partial benefit when their neighbor(s) receive the resource. We thus introduce networked restless bandits, a novel multi-armed bandit setting in which arms are both restless and embedded within a directed graph. We then present Greta, a graph-aware, Whittle index-based heuristic algorithm that can be used to efficiently construct a constrained reward-maximizing action vector at each timestep. Our empirical results demonstrate that Greta outperforms comparison policies across a range of hyperparameter values and graph topologies.Comment: Accepted to AAAI 202

Discovering Latent Gender Bias in Children\u27s STEM Literature

A mixed method, exploratory, sequential research design was conducted to investigate the presence of latent bias in early childhood STEM literature content, applying a non-biased, sociocultural, STEM identity, theoretical framework. A survey of children\u27s perceptions of gender and a content analysis found unintentional bias. Exploratory findings confirmed 102 children were gendering images. An examination of the relationship between the participants\u27 gender and how the participant gendered AND preferred the images indicated differences existed between boys and girls. Children preferred images perceived as matching their own, with statistical significance. Girls were found to prefer images less than boys AND they were more likely to gender the images. Children were more likely to give gender to the 50 images considered in the study, than to non-gender them. The gendering and preference was found to be statistically significantly higher for anthropomorphic and personified inanimate images. Additionally, a content analysis of eight award winning and popular selling STEM children\u27s books were conducted and were found to contain biased narratives and image content. A content analysis found significant differences relating to the frequency of character representation in the eight books. Analysis indicated a higher lexical representation of females to males, and image representation was more male than female. Further analysis of additional books and images is warranted from the findings of this exploratory study

Planning to Fairly Allocate: Probabilistic Fairness in the Restless Bandit Setting

Restless and collapsing bandits are commonly used to model constrained resource allocation in settings featuring arms with action-dependent transition probabilities, such as allocating health interventions among patients [Whittle, 1988; Mate et al., 2020]. However, state-of-the-art Whittle-index-based approaches to this planning problem either do not consider fairness among arms, or incentivize fairness without guaranteeing it [Mate et al., 2021]. Additionally, their optimality guarantees only apply when arms are indexable and threshold-optimal. We demonstrate that the incorporation of hard fairness constraints necessitates the coupling of arms, which undermines the tractability, and by extension, indexability of the problem. We then introduce ProbFair, a probabilistically fair stationary policy that maximizes total expected reward and satisfies the budget constraint, while ensuring a strictly positive lower bound on the probability of being pulled at each timestep. We evaluate our algorithm on a real-world application, where interventions support continuous positive airway pressure (CPAP) therapy adherence among obstructive sleep apnea (OSA) patients, as well as simulations on a broader class of synthetic transition matrices.Comment: 27 pages, 19 figure

New Mandates and Imperatives in the Revised ACA Code of Ethics

The first major revision of the ACA Code of Ethics in a decade occurred in late 2005, with the updated edition containing important new mandates and imperatives. This article provides interviews with members of the Ethics Revision Task Force that flesh out seminal changes in the revised ACA Code of Ethics in the areas of confidentiality, romantic and sexual interactions, dual relationships, end-of-life care for terminally ill clients, cultural sensitivity, diagnosis, interventions, practice termination, technology, and deceased clients

Ecological effects of nitrogen and sulfur air pollution in the US: what do we know?

Four decades after the passage of the US Clean Air Act, air-quality standards are set to protect ecosystems from damage caused by gas-phase nitrogen (N) and sulfur (S) compounds, but not from the deposition of these air pollutants to land and water. Here, we synthesize recent scientific literature on the ecological effects of N and S air pollution in the US. Deposition of N and S is the main driver of ecosystem acidification and contributes to nutrient enrichment in many natural systems. Although surface-water acidification has decreased in the US since 1990, it remains a problem in many regions. Perturbations to ecosystems caused by the nutrient effects of N deposition continue to emerge, although gas-phase concentrations are generally not high enough to cause phytotoxicity. In all, there is overwhelming evidence of a broad range of damaging effects to ecosystems in the US under current air-quality conditions

Counselor Education Doctoral Students\u27 Experiences with Multiple Roles and Relationships

Interpretive phenomenological analysis was used to explore 10 counselor education doctoral students\u27 lived experiences with multiple roles and relationships. Four superordinate themes were found: power differential, need for education, transformation, and learning from experiences. Findings revealed that multiple roles and relationships offer doctoral students positive and negative experiences, shaping their development as future counselor educators

Trissolcus japonicus (Ashmead) (Hymenoptera, Scelionidae) emerges in North America

Trissolcus japonicus (Ashmead) is an Asian egg parasitoid of the brown marmorated stink bug, Halyomorpha halys (Stål). It has been under study in U.S. quarantine facilities since 2007 to evaluate its efficacy as a candidate classical biological control agent and its host specificity with regard to the pentatomid fauna native to the United States. A survey of resident egg parasitoids conducted in 2014 with sentinel egg masses of H. halys revealed that T. japonicus was already present in the wild in Beltsville, MD. Seven parasitized egg masses were recovered, of which six yielded live T. japonicus adults. All of these were in a wooded habitat, whereas egg masses placed in nearby soybean fields and an abandoned apple orchard showed no T. japonicus parasitism. How T. japonicus came to that site is unknown and presumed accidental