IL-15 augments TCR-induced CD4⁺ T cell expansion in vitro by inhibiting the suppressive function of CD25High CD4⁺ T cells

Due to its critical role in NK cell differentiation and CD8(+) T cell homeostasis, the importance of IL-15 is more firmly established for cytolytic effectors of the immune system than for CD4(+) T cells. The increased levels of IL-15 found in several CD4(+) T cell-driven (auto-) immune diseases prompted us to examine how IL-15 influences murine CD4(+) T cell responses to low dose TCR-stimulation in vitro. We show that IL-15 exerts growth factor activity on both CD4(+) and CD8+ T cells in a TCR-dependent and Cyclosporin A-sensitive manner. In CD4(+) T cells, IL-15 augmented initial IL-2-dependent expansion and once IL-15R alpha was upregulated, IL-15 sustained the TCR-induced expression of IL-2/15R beta, supporting proliferation independently of secreted IL-2. Moreover, IL-15 counteracts CD4(+) T cell suppression by a gradually expanding CD25(High)CD4(+) T cell subset that expresses Foxp3 and originates from CD4(+)CD25(+) Tregs. These in vitro data suggest that IL-15 may dramatically strengthen the T cell response to suboptimal TCR-triggering by overcoming an activation threshold set by Treg that might create a risk for autoimmune pathology

An Information Management Protocol to Control Routing and Clustering in Sensor Networks

In this paper, we develop and analyze a novel clustering protocol, Decentralized Energy Efficient cluster Propagation (DEEP), that attempts to manage the communication of data while minimizing energy consumption across the sensor networks. We also develop an Inter-Cluster Routing protocol (ICR) that is compatible with the proposed clustering technique. DEEP takes advantage of the multi-rate capabilities of 802.11a, b, g technologies by elevating the data rate to higher levels for shorter transmission ranges. This approach reduces the energy consumption by lowering the transmission time. Protocol DEEP starts with an initial cluster head and gradually forms clusters throughout the network by controlling the geographical dimensions of clusters and distribution of cluster heads in order to conserve energy and prolong network lifetime. Furthermore, due to the balanced load, protocol overhead caused by unnecessary frequent re-clustering is eradicated. Our simulation results demonstrate that DEEP distributes energy consumption approximately 8 times better than an existing clustering scheme, LEACH. In addition, DEEP substantially reduces total data communication and route setup energy consumption in the network compared to LEACH

Women in engineering: Promoting identity exploration and professional development

Engineering colleges are concerned about retention of women, especially women of color, in their programs. One possible solution is to promote undergraduate women\u27s engineering identity. This paper describes an evaluation of a one-day technical and professional development conference for undergraduate women in engineering and computer science, which focused on understanding and facilitating engineering identity. Data on the impact of the conference and engineering identity, were collected in pre- and post-conference surveys. The pre-conference survey assessed demographic information (e.g., first generation status, ethnicity), engineering student identity (i.e., commitment to engineering major; engineering competence, and engineering agency), social support, and reasons for attending. The post-conference survey assessed engineering student identity, ratings of self- and engineer creativity, professional identity, and evaluations of the conference. 193 participants returned pre-conference surveys and 103 returned post-conference surveys. Most were engineering (54%) and computer science (38%) majors; 46% were Asian, 28% LatinX; and 65% received financial aid. Correlations, MANOVA, regression, and content analyses were used to analyze the data. Participants reported the conference was highly valuable. Both pre- and post-conference surveys revealed positive associations between commitment, competence, and agency, suggesting that undergraduate women view their engineering identities as a coherent set. Results indicated that the strength of a participant\u27 professional identity is shaped by first-generation status and knowing an engineer. They also indicated that women undergraduates do not rate themselves as being as creative as a typical engineer, and there is a strong association between self-ratings of creativity and professional identity. Engineering identity is discussed in the context of participants\u27 reported goals for the conference and its benefits. Suggestions for promoting engineering identity are described

A technology pathway program in data technology and applications

With an exponential increase in user-generated data, there is a strong and increasing demand for employees possessing both technical skills and knowledge of human behavior. Supported by funds from the National Science Foundation Division of Undergraduate Education, we have begun to address this need by developing a technology pathway program in data technology and applications at a large, minority-serving public university. As part of this program, an interdisciplinary team of faculty created a new minor in Applied Computing for Behavioral and Social Sciences. A large number of diverse students are studying behavioral and social sciences, and the ability to model human behaviors and social interactions is a highly valuable skill set in our increasingly data-driven world. Applied Computing students complete a four-course sequence that focuses on data analytics and includes data structures and algorithms, data cleaning and management, SQL, and a culminating project. Our first full cohort of students completed the Applied Computing minor in Spring 2019. To assess the success of the minor, we conduct student surveys and interviews in each course. Here, we focus on survey data from the beginning and end of the first course, given that it served as a particularly important feedback loop to optimize the course and to inform the design and execution of subsequent courses. The data reflect a significant increase in confidence in programming abilities over time, as well as a shift in attitudes about programming that more closely matches those of experts. The data did not show a significant change in mindset over time, such that students maintained a growth mindset across the semester. Finally, with respect to goals, students placed a greater emphasis on data and tech at the end of the semester, highlighting specific career paths such as user experience and human factors. In the future, we plan to administer this same survey to social science students not involved in the minor to serve as a control group and to begin exploring the large dataset obtained from other courses in the minor. We believe that embedding computing education into the social sciences is a promising means of diversifying the technical workforce and filling the need for interdisciplinary computing professionals, as evidenced by high rates of female and underrepresented minority enrollment in our courses, as well as promising shifts in student confidence, attitudes, and career goals as a result of taking Applied Computing courses

Persistent termini of 2004- and 2005-like ruptures of the Sunda megathrust

To gain insight into the longevity of subduction zone segmentation, we use coral microatolls to examine an 1100-year record of large earthquakes across the boundary of the great 2004 and 2005 Sunda megathrust ruptures. Simeulue, a 100-km-long island off the west coast of northern Sumatra, Indonesia, straddles this boundary: northern Simeulue was uplifted in the 2004 earthquake, whereas southern Simeulue rose in 2005. Northern Simeulue corals reveal that predecessors of the 2004 earthquake occurred in the 10th century AD, in AD 1394 ± 2, and in AD 1450 ± 3. Corals from southern Simeulue indicate that none of the major uplifts inferred on northern Simeulue in the past 1100 years extended to southern Simeulue. The two largest uplifts recognized at a south-central Simeulue site—around AD 1422 and in 2005—involved little or no uplift of northern Simeulue. The distribution of uplift and strong shaking during a historical earthquake in 1861 suggests the 1861 rupture area was also restricted to south of central Simeulue, as in 2005. The strikingly different histories of the two adjacent patches demonstrate that this boundary has persisted as an impediment to rupture through at least seven earthquakes in the past 1100 years. This implies that the rupture lengths, and hence sizes, of at least some future great earthquakes and tsunamis can be forecast. These microatolls also provide insight into megathrust behavior between earthquakes, revealing sudden and substantial changes in interseismic strain accumulation rates

Learning Experiences of Social Science Students in an Interdisciplinary Computing Minor

The rapid growth of the digital economy and an associated increase in user-generated data has created a strong need for interdisciplinary computing professionals possessing both technical skills and knowledge of human behavior. To help meet this need and with funds from NSF IUSE, we developed an academic minor in Applied Computing for Behavioral and Social Sciences at San Jose State University. The minor involves a four-course sequence that includes programming fundamentals, data structures and algorithms, data cleaning and management, and a culminating project. At our institution and nationwide, social science students are more diverse than engineering students, with respect to gender, race, and ethnicity. By providing social science students with computing skills that complement their domain expertise, we aim to expand their career options and address the nation\u27s need for a diverse, technology-capable workforce. We administered an exit survey on student learning experiences to two cohorts of students completing the minor. Given that the minor is new and that the first cohorts were relatively small, the number of students completing the survey was modest (n = 15). Results indicate that students were motivated to minor in Applied Computing by a desire to improve their data analysis skills and better prepare themselves for the job market/graduate school, as well as a belief that programming is a necessary skill for the future. A large majority of students indicated that their peers, instructors, and homework assignments supported their learning very well, whereas they found topics covered and course projects to be less supportive, followed by pacing of course content. With respect to career plans, a majority of students agreed that the minor provided them with their desired skills and allowed them to learn about careers in applied computing, and a large majority indicated that they planned to pursue a career utilizing applied computing. They expressed interest in fields such as human factors, data analytics, project management, teaching, clinical psychology, and various types of research. Finally, common themes that arose when providing advice to future students included not being shy in seeking help, tips for managing the level of course difficulty, encouragement to regularly practice, suggestions for how to master course content, and advice for adopting a successful mindset. These results will be instrumental in helping to optimize students\u27 experiences in the minor, ranging from how we recruit new students to how we can better support their professional development. Given the largely positive experiences of our students and their plans to pursue careers involving applied computing, we believe that our approach of adding computing education alongside a social science degree demonstrates a promising model for meeting the increasing demand for diverse interdisciplinary computing workers in this digital age

Flavor SU(3) analysis of charmless B meson decays to two pseudoscalar mesons

Global fits to charmless B --> PP decays in the framework of flavor SU(3) symmetry are updated and improved without reference to the \sin2\beta measured from the charmonium decay modes. Fit results directly constrain the (\bar\rho,\bar\eta) vertex of the unitarity triangle, and are used to predict the branching ratios and CP asymmetries of all decay modes, including those of the B_s system. Different schemes of SU(3) breaking in decay amplitude sizes are analyzed. The major breaking effect between strangeness-conserving and strangeness-changing decays can be accounted for by including a ratio of decay constants in tree and color-suppressed amplitudes. The possibility of having a new physics contribution to K \pi decays is also examined from the data fitting point of view.Comment: 22 pages and 2 figures; some comments and references added; more references added, version to appear in journa

Flavor symmetry analysis of charmless B --> VP decays

Based upon flavor SU(3) symmetry, we perform global fits to charmless B decays into one pseudoscalar meson and one vector meson in the final states. We consider different symmetry breaking schemes and find that the one implied by na{\"i}ve factorization is slightly favored over the exact symmetry case. The $(\bar\rho,\bar\eta)$ vertex of the unitarity triangle (UT) constrained by our fits is consistent with other methods within errors. We have found large color-suppressed, electroweak penguin and singlet penguin amplitudes when the spectator quark ends up in the final-state vector meson. Nontrivial relative strong phases are also required to explain the data. The best-fit parameters are used to compute branching ratio and CP asymmetry observables in all of the decay modes, particularly those in the $B_s$ decays to be measured at the Tevatron and LHC experiments.Comment: 23 pages and 2 plots; updated with ICHEP'08 data and expanded in discussions and reference

The Powerful Role of Mothers in Adolescent Purpose Development

Adolescence is a critical time for the cultivation of life purpose, also known as a meaningful long-term aim focused on contribution to others. Youth with purpose, especially marginalized youth, report a number of positive outcomes. Relationships with caring adults appear to be particularly helpful in guiding young people on their path to purpose, but little work has focused specifically on the role of mothers. This qualitative study, approved by a Institutional Review Board, examines how twenty adolescents from marginalized communities describe their sense of purpose and its relationship to their caregivers. The sample size was determined based on saturation, a process in qualitative research when the researchers begin to observe redundancy in the data. Through content analysis, a major theme emerged: the role of mothers and their impact on purpose development on their children. Results showed that mothers helped their adolescents develop their sense of purpose through serving as a sense of inspiration, providing the adolescents with support, sparking a desire for the adolescents to make their mothers proud, and through the mothers and adolescents in engaging in conversations about one’s future

Flavor Changing Effects in Family Nonuniversal Z' Models

Flavor-changing and CP-violating interactions of Z' to fermions are generally present in models with extra U(1) gauge symmetry that are string-inspired or related to broken gauged family symmetry. We study the consequences of such couplings in fermion electric dipole moments, muon g-2, and K and B meson mixings. From experimental limits or measured values, we constrain the off-diagonal Z' couplings to fermions. Some of these constraints are comparable or stronger than the existing constraints obtained from other observables.Comment: 17 pages, 2 figure