Asymmetric B Cell Division in the Germinal Center Reaction

Antibody responses are one of the major defense mechanisms that mammals employ against microbial infections. As such, these responses have been targeted by most vaccine regimens used to prevent infections. However, in spite of the success of current vaccines, our understanding of how humoral immune responses develop is incomplete. A better understanding of the immunology behind humoral immunity will help in the future design of effective vaccine regimens. Much of the work done toward understanding humoral immunity has focused on the germinal center (GC) reaction. GC reactions are initiated after infections and vaccinations when B cells are activated through the B cell receptor (BCR) and interact with the other members of the responding immune system, including helper T cells. GC B cells proliferate while improving their BCR, and ultimately go on to differentiate into plasma cells that secrete protective antibodies and memory B cells that can respond to re-infection in the future. The extrinsic mechanisms by which GC B cells adopt these mutually exclusive fates have been extensively researched, but we considered that GC B cells may exercise cell-intrinsic control over their differentiation. Specifically, we hypothesized that GC B cells use asymmetric cell division to accomplish the multiple tasks set before them. Using confocal microscopy we examined dividing GC B cells and observed that two drivers of GC B cell differentiation, Bcl6 and the receptor for the cytokine IL-21 (IL-21R), are asymmetrically segregated during mitosis and unequally inherited by the resulting daughter B cells. This process is dependent on the evolutionarily conserved regulator of polarity, aPKC, and GC B cells are stimulated to divide asymmetrically by contacts made with helper T cells. By examining humoral immune responses in mice in which GC B cells do not divide asymmetrically, we have shown that asymmetric division is not required for B cell differentiation, while cell-cell contacts are absolutely critical to their differentiation. These data suggest that, in addition to signals from the environment of the GC reaction, diversity of GC B cell function may be supported by cell-cell interactions in the GC reaction

Building an Argument for the Use of Science Fiction in HCI Education

Science fiction literature, comics, cartoons and, in particular, audio-visual materials, such as science fiction movies and shows, can be a valuable addition in Human-computer interaction (HCI) Education. In this paper, we present an overview of research relative to future directions in HCI Education, distinct crossings of science fiction in HCI and Computer Science teaching and the Framework for 21st Century Learning. Next, we provide examples where science fiction can add to the future of HCI Education. In particular, we argue herein first that science fiction, as tangible and intangible cultural artifact, can serve as a trigger for creativity and innovation and thus, support us in exploring the design space. Second, science fiction, as a means to analyze yet-to-come HCI technologies, can assist us in developing an open-minded and reflective dialogue about technological futures, thus creating a singular base for critical thinking and problem solving. Provided that one is cognizant of its potential and limitations, we reason that science fiction can be a meaningful extension of selected aspects of HCI curricula and research.Comment: 6 pages, 1 table, IHSI 2019 accepted submissio

Identifying patterns of item missing survey data using latent groups: An observational study

Objectives: To examine whether respondents to a survey of health and physical activity and potential determinants could be grouped according to the questions they missed, known as ‘item missing’. Design: Observational study of longitudinal data. Setting: Residents of Brisbane, Australia. Participants: 6901 people aged 40–65 years in 2007. Materials and methods: We used a latent class model with a mixture of multinomial distributions and chose the number of classes using the Bayesian information criterion. We used logistic regression to examine if participants’ characteristics were associated with their modal latent class. We used logistic regression to examine whether the amount of item missing in a survey predicted wave missing in the following survey. Results: Four per cent of participants missed almost one-fifth of the questions, and this group missed more questions in the middle of the survey. Eighty-three per cent of participants completed almost every question, but had a relatively high missing probability for a question on sleep time, a question which had an inconsistent presentation compared with the rest of the survey. Participants who completed almost every question were generally younger and more educated. Participants who completed more questions were less likely to miss the next longitudinal wave. Conclusions: Examining patterns in item missing data has improved our understanding of how missing data were generated and has informed future survey design to help reduce missing data

Developing the Potential of Observation - Generating Ideas Using Video Data From a Nursery School: a Students as Academic Partners Project

This Students as Academic Partners (SAP) project aimed to explore the potential of a creative approach to reflection. Developing approaches to reflective practice is directly relevant for a wide range of professional occupations including school teachers, early years practitioners, lecturers within HE and also trainees. Individual reflections were produced by project participants based on several very short video clips of children in a nursery school. The reflections include speculative observations, explanations and use of theoretical perspectives linked to broader themes. The analysis was extended through a collaborative reflection on the combined individual reflections. The focus on broader themes within this particular project seeks to contribute to an encompassing discourse related to early years practice

Creative Reflection in Action

This (Students as Academic Partners) project aimed to explore the potential of a creative approach to reflection. Developing approaches to reflective practice is directly relevant for teachers and those who are training to become teachers. Individual reflections were produced by project participants based on several very short video clips of children in a nursery school. These individual reflections were extended into a collaborative reflection highlighting common themes. This broader focus seeks to contribute to an encompassing discourse related to early years practice. The poster aims to show how critical reflection and speculation can develop an understanding of the child, their development and potential barriers to this development. Through observing stills from the video footage, viewers of the poster are challenged to speculate about the child’s body language, what they might be doing or whether the learning environment is suitable to develop and progress their knowledge and understanding further

Application of a stochastic weather generator to assess climate change impacts in a semi-arid climate: The Upper Indus Basin

Assessing local climate change impacts requires downscaling from Global Climate Model simulations. Here, a stochastic rainfall model (RainSim) combined with a rainfall conditioned weather generator (CRU WG) have been successfully applied in a semi-arid mountain climate, for part of the Upper Indus Basin (UIB), for point stations at a daily time-step to explore climate change impacts. Validation of the simulated time-series against observations (1961–1990) demonstrated the models’ skill in reproducing climatological means of core variables with monthly RMSE of <2.0 mm for precipitation and ⩽0.4 °C for mean temperature and daily temperature range. This level of performance is impressive given complexity of climate processes operating in this mountainous context at the boundary between monsoonal and mid-latitude (westerly) weather systems. Of equal importance the model captures well the observed interannual variability as quantified by the first and last decile of 30-year climatic periods. Differences between a control (1961–1990) and future (2071–2100) regional climate model (RCM) time-slice experiment were then used to provide change factors which could be applied within the rainfall and weather models to produce perturbed ‘future’ weather time-series. These project year-round increases in precipitation (maximum seasonal mean change:+27%, annual mean change: +18%) with increased intensity in the wettest months (February, March, April) and year-round increases in mean temperature (annual mean +4.8 °C). Climatic constraints on the productivity of natural resource-dependent systems were also assessed using relevant indices from the European Climate Assessment (ECA) and indicate potential future risk to water resources and local agriculture. However, the uniformity of projected temperature increases is in stark contrast to recent seasonally asymmetrical trends in observations, so an alternative scenario of extrapolated trends was also explored. We conclude that interannual variability in climate will continue to have the dominant impact on water resources management whichever trajectory is followed. This demonstrates the need for sophisticated downscaling methods which can evaluate changes in variability and sequencing of events to explore climate change impacts in this region

13C NMR study of the mode of interaction in solution of the B fragment of staphylococcal protein A and the Fc fragments of mouse immunoglobulin G

AbstractThe mode of interaction of the B domain (FB) of staphylococcal protein A and the Fc fragments of mouse immunoglobulin G (IgG) has been investigated by 13C NMR spectroscopy. Mouse IgG1, IgG2a, and IgG2b proteins have been selectively labeled with 13C at the carbonyl carbon of His, Met, Trp or Tyr residue and used to prepare the corresponding Fc fragments by limited proteolysis. Site-specific resonance assignments have been made for each of these Fc analogues. FB was reported to form two contacts (contact 1 and contact 2) with human Fc in the crystal [Biochemistry 20 (1981) 2361-2370]. Comparisons of the chemical shift data of the Fc fragments observed in the absence and presence of FB have led us to conclude that in solution contact 1 is responsible for the formation of the Fc-FB complexes

1978: Abilene Christian College Bible Lectures - Full Text

SPIRITUALITY Being the Abilene Christian University Annual Bible Lectures 1978 Published by Abilene Christian University Book Store ACU Station Abilene, Texas 7960