Finding new friends or falling back on familiar faces: the peer affiliations of aggressive students during the transition to middle school

This study investigated the school-based peer affiliations of youth during the transition to middle school. One-hundred seventy one participants were followed over the first three semesters of middle school to examine students' affiliation patterns with previously familiar peers who attended the same elementary school. A series of univariate and repeated measures ANOVAs were used to detect changes in peer affiliations. Overall, students were more likely to affiliate with a greater proportion of previously familiar peers when they arrived at middle school, but there was a linear decline in the proportion of familiar peers within peer groups over time. Boys showed little change in affiliations with familiar peers, while girls showed a steady decline in the proportion of familiar peers within their peer groups. Students rated as physically aggressive by teachers and peers did not affiliate with a significantly different proportion of familiar peers than non-aggressive students at all time points. However, students rated as socially aggressive by peers, but not teachers, affiliated with a greater proportion of familiar peers than non-aggressive students during the first two semesters of middle school

WIP: Development of a Student-Centered Personalized Learning Framework to Advance Undergraduate Robotics Education

This paper presents a work-in-progress on a learn-ing system that will provide robotics students with a personalized learning environment. This addresses both the scarcity of skilled robotics instructors, particularly in community colleges and the expensive demand for training equipment. The study of robotics at the college level represents a wide range of interests, experiences, and aims. This project works to provide students the flexibility to adapt their learning to their own goals and prior experience. We are developing a system to enable robotics instruction through a web-based interface that is compatible with less expensive hardware. Therefore, the free distribution of teaching materials will empower educators. This project has the potential to increase the number of robotics courses offered at both two- and four-year schools and universities. The course materials are being designed with small units and a hierarchical dependency tree in mind; students will be able to customize their course of study based on the robotics skills they have already mastered. We present an evaluation of a five module mini-course in robotics. Students indicated that they had a positive experience with the online content. They also scored the experience highly on relatedness, mastery, and autonomy perspectives, demonstrating strong motivation potential for this approach.Comment: 5 pages, 2 figures, conferenc

The Role of Social Capital in Educational Aspirations of Rural Youth*: Educational Aspirations of Rural Youth

Drawing on a recent national survey of rural high school students, this study investigated the relationship between social capital and educational aspirations of rural youth. Results showed that various process features of family and school social capital were important to predict rural youth's educational aspirations beyond sociodemographic background. In particular, parents' and teachers' educational expectations for their child and student respectively were positively related to educational aspirations of rural youth. In addition, discussion with parents about college was positively related to educational aspirations of rural youth. On the other hand, there was little evidence to suggest that number of siblings and school proportions of students on free lunch and minority students are related to educational aspirations of rural youth, after controlling for the other variables. The authors highlight unique features of rural families, schools, and communities that may combine to explain the complexity of the role of social capital in shaping educational aspirations of rural youth

Educational Barriers of Rural Youth: Relation of Individual and Contextual Difference Variables

The purpose of this study was to examine the relation of several individual and contextual difference factors to the perceived educational barriers of rural youth. Data were from a broader national investigation of students’ postsecondary aspirations and preparation in rural high schools across the United States. The sample involved more than 7,000 rural youth in 73 high schools across 34 states. Results indicated that some individual (e.g., African American race/ethnicity) and contextual (e.g., parent education) difference factors were predictive while others were not. Extensions to, similarities, and variations with previous research are discussed. Implications, limitations, and suggestions for future research are also discussed

The Formation of the First Stars in the Universe

In this review, I survey our current understanding of how the very first stars in the universe formed, with a focus on three main areas of interest: the formation of the first protogalaxies and the cooling of gas within them, the nature and extent of fragmentation within the cool gas, and the physics -- in particular the interplay between protostellar accretion and protostellar feedback -- that serves to determine the final stellar mass. In each of these areas, I have attempted to show how our thinking has developed over recent years, aided in large part by the increasing ease with which we can now perform detailed numerical simulations of primordial star formation. I have also tried to indicate the areas where our understanding remains incomplete, and to identify some of the most important unsolved problems.Comment: 74 pages, 4 figures. Accepted for publication in Space Science Review

The First Stars

The first stars to form in the Universe -- the so-called Population III stars -- bring an end to the cosmological Dark Ages, and exert an important influence on the formation of subsequent generations of stars and on the assembly of the first galaxies. Developing an understanding of how and when the first Population III stars formed and what their properties were is an important goal of modern astrophysical research. In this review, I discuss our current understanding of the physical processes involved in the formation of Population III stars. I show how we can identify the mass scale of the first dark matter halos to host Population III star formation, and discuss how gas undergoes gravitational collapse within these halos, eventually reaching protostellar densities. I highlight some of the most important physical processes occurring during this collapse, and indicate the areas where our current understanding remains incomplete. Finally, I discuss in some detail the behaviour of the gas after the formation of the first Population III protostar. I discuss both the conventional picture, where the gas does not undergo further fragmentation and the final stellar mass is set by the interplay between protostellar accretion and protostellar feedback, and also the recently advanced picture in which the gas does fragment and where dynamical interactions between fragments have an important influence on the final distribution of stellar masses.Comment: 72 pages, 4 figures. Book chapter to appear in "The First Galaxies - Theoretical Predictions and Observational Clues", 2012 by Springer, eds. V. Bromm, B. Mobasher, T. Wiklin

Tracking down carbon inputs underground from an arid zone Australian calcrete.

Freshwater ecosystems play a key role in shaping the global carbon cycle and maintaining the ecological balance that sustains biodiversity worldwide. Surficial water bodies are often interconnected with groundwater, forming a physical continuum, and their interaction has been reported as a crucial driver for organic matter (OM) inputs in groundwater systems. However, despite the growing concerns related to increasing anthropogenic pressure and effects of global change to groundwater environments, our understanding of the dynamics regulating subterranean carbon flows is still sparse. We traced carbon composition and transformations in an arid zone calcrete aquifer using a novel multidisciplinary approach that combined isotopic analyses of dissolved organic carbon (DOC) and inorganic carbon (DIC) (δ13CDOC, δ13CDIC, 14CDOC and 14CDIC) with fluorescence spectroscopy (Chromophoric Dissolved OM (CDOM) characterisation) and metabarcoding analyses (taxonomic and functional genomics on bacterial 16S rRNA). To compare dynamics linked to potential aquifer recharge processes, water samples were collected from two boreholes under contrasting rainfall: low rainfall ((LR), dry season) and high rainfall ((HR), wet season). Our isotopic results indicate limited changes and dominance of modern terrestrial carbon in the upper part (northeast) of the bore field, but correlation between HR and increased old and 13C-enriched DOC in the lower area (southwest). CDOM results show a shift from terrestrially to microbially derived compounds after rainfall in the same lower field bore, which was also sampled for microbial genetics. Functional genomic results showed increased genes coding for degradative pathways-dominated by those related to aromatic compound metabolisms-during HR. Our results indicate that rainfall leads to different responses in different parts of the bore field, with an increase in old carbon sources and microbial processing in the lower part of the field. We hypothesise that this may be due to increasing salinity, either due to mobilisation of Cl- from the soil, or infiltration from the downstream salt lake during HR. This study is the first to use a multi-technique assessment using stable and radioactive isotopes together with functional genomics to probe the principal organic biogeochemical pathways regulating an arid zone calcrete system. Further investigations involving extensive sampling from diverse groundwater ecosystems will allow better understanding of the microbiological pathways sustaining the ecological functioning of subterranean biota

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Planning for the Future: An Investigation of Work-Bound Rural Youth

The purpose of this study was to explore the postsecondary educational and occupational expectations of work-bound rural youth. Three groups of work-bound youth were identified (work-bound, work-bound with future educational plans, and work-bound but unsure/undecided about postsecondary education), and each group was compared to college-bound rural youth using results from a recent national investigation of the educational and occupational aspirations of rural youth. Results indicated that the majority of rural youth in this study planned to continue their education after high school (56%), followed by 34% who planned to work and further their education. Results of logistic regression analysis indicated that family characteristics and students’ schooling experiences were the strongest predictors of work-bound status. Work-bound youth were more likely to report greater family economic hardship, lower parental expectations for completing college, and more negative schooling experiences than college-bound rural youth. Acknowledgements: This research was supported by a grant from the U.S. Department of Education’s Institute of Education Sciences (R305A04056) awarded to the NRCRES at the University of North Carolina-Chapel Hill. The views expressed in this article are those of the authors and do not necessarily reflect those of the granting agency