Knowledge Flow Analysis for Security Protocols

Knowledge flow analysis offers a simple and flexible way to find flaws in security protocols. A protocol is described by a collection of rules constraining the propagation of knowledge amongst principals. Because this characterization corresponds closely to informal descriptions of protocols, it allows a succinct and natural formalization; because it abstracts away message ordering, and handles communications between principals and applications of cryptographic primitives uniformly, it is readily represented in a standard logic. A generic framework in the Alloy modelling language is presented, and instantiated for two standard protocols, and a new key management scheme.Comment: 20 page

Mitochondrial translocation of oxidized cofilin induces caspase-independent necrotic-like programmed cell death of T cells

Oxidative stress leads to T-cell hyporesponsiveness or death. The actin-binding protein cofilin is oxidized during oxidative stress, which provokes a stiff actin cytoskeleton and T-cell hyporesponsiveness. Here, we show that long-term oxidative stress leads to translocation of cofilin into the mitochondria and necrotic-like programmed cell death (PCD) in human T cells. Notably, cofilin mutants that functionally mimic oxidation by a single mutation at oxidation-sensitive cysteins (Cys-39 or Cys-80) predominately localize within the mitochondria. The expression of these mutants alone ultimately leads to necrotic-like PCD in T cells. Accordingly, cofilin knockdown partially protects T cells from the fatal effects of long-term oxidative stress. Thus, we introduce the oxidation and mitochondrial localization of cofilin as the checkpoint for necrotic-like PCD upon oxidative stress as it occurs, for example, in tumor environments

Laboratory in Software Engineering

Introduces concepts and techniques relevant to the production of large software systems. Students taught a programming method based on the recognition and description of useful abstractions. Topics: modularity; specification; data abstraction; object modeling; design patterns; and testing. Several programming projects of varying size undertaken by students working individually and in groups. Enrollment may be limited. 12 Engineering Design Points

Selenoproteins Mediate T Cell Immunity through an Antioxidant Mechanism*S⃞

Selenium is an essential dietary element with antioxidant roles in immune regulation, but there is little understanding of how this element acts at the molecular level in host defense and inflammatory disease. Selenium is incorporated into the amino acid selenocysteine (Sec), which in turn is inserted into selenoproteins in a manner dependent on Sec tRNA[Ser]Sec. To investigate the molecular mechanism that links selenium to T cell immunity, we generated mice with selenoprotein-less T cells by cell type-specific ablation of the Sec tRNA[Ser]Sec gene (trsp). Herein, we show that these mutant mice exhibit decreased pools of mature T cells and a defect in T cell-dependent antibody responses. We also demonstrate that selenoprotein deficiency leads to oxidant hyperproduction in T cells and thereby suppresses T cell proliferation in response to T cell receptor stimulation. These findings offer novel insights into immune function of selenium and physiological antioxidants

Q Chat Space: Assessing the Feasibility and Acceptability of an Internet-Based Support Program for LGBTQ Youth

There are few psychosocial support programs specifically designed to meet the unique developmental and health needs of LGBTQ youth. Even when available, many youth face significant barriers to accessing LGBTQ-specific services for fear of being “outed” to parents, peers, and community members. The current study assessed the utility, feasibility, and acceptability of a synchronous, adult-facilitated, chat-based Internet community support program for LGBTQ youth aged 13–19. Chat transcripts were analyzed to examine how LGBTQ youth used the chat-based platform to connect with peers and trusted adults. A separate user satisfaction survey was collected to assess the personal (e.g., sexual orientation, gender identity, age) and contextual (e.g., geography, family environment) characteristics of youth engaging in the platform, their preferred topics of discussion, and their satisfaction with the program focus and facilitators. Qualitative data analysis demonstrated the degree to which LGBTQ youth were comfortable disclosing difficult and challenging situations with family, friends, and in their community and in seeking support from peers and facilitators online. Youth also used the platform to explore facets of sexual and gender identity/expression and self-acceptance. Overall, users were very satisfied with the platform, and participants accurately reflect the program’s desired populations for engagement (e.g., LGBTQ youth of color, LGBTQ youth in the South). Together, findings support the feasibility and acceptability of synchronous, adult-facilitated, chat-based Internet programs to connect and support LGBTQ youth, which encourage future research and innovation in service delivery