Molecular Gas Around Young Stellar Clusters

We have begun a survey of the molecular gas surrounding 31 young clusters in order to investigate the link between environment and the resulting cluster. We present here a preliminary comparison of two clusters in our sample: GGD12-15 and Mon R2. Since both clusters are located in the MonR2 molecular cloud at a distance of 830 pc, observational biases due to differing sensitivities and angular resolutions are avoided.Comment: 2 pages, 2 figures, uses newpasp.sty. To appear in "Hot Star Workshop III: The Earliest Phases of Massive Star Birth" (ed. P.A. Crowther

What is, and what might be, learned from images shared during Twitter conversations among professionals?

This thesis explores the pedagogical potential of images shared during intra-professional conversations held on the social media platform, Twitter. Twitter chats are loosely synchronous exchanges of tweets sharing a unique, identifying keyword or hashtag. They are increasingly being used among professionals to create professional networks in which practice-knowledge and opinion might be shared and where communal connections may be created. As such, they may serve as sites in which professional learning unfolds, both in relation to workplace practices and in relation to the development of new forms of professional practice around social media use. Because the exchanges and broadcasts on Twitter are, for the most part, public, and the conversations are ongoing, they also provide open, freely-accessible, and constantly renewing resources for use in pre-service learning contexts. The research focused on two example chats, one held among midwives and the other among teachers. Inspired by the increasing use of images in new forms of digital communication, the research used images tweeted during the chats as starting points from which to explore flows of knowledge and affect. Data were generated from observations of the two Twitter chats over extended periods, together with interviews with practising professionals, student professionals and their educators in which images were used as elicitation devices. The research combined an approach to reading and “being with” data inspired by ideas drawn from the work of Deleuze (1994; Williams 2013) and Deleuze and Guattari (1988; Massumi 1992), with approaches to reading images drawn from visual social semiotics (Kress and van Leeuwen 1996). The findings suggest that Twitter chats such as those studied here can provide rich opportunities for professional learning. Practice knowledge can flow from one participant to many others, and flows of affect can be used to remoralize individuals and communities. Both chats seemed to serve as sites in which professionals could experience a positivity and affirmation that was not always available in the workplace. However, the forces and intensities at play in these spaces influence both what is said and what is not said, creating new norms of online interaction that generally seemed to avoid negative comments or open disagreement. Educators saw potential to use images such as those shared in the chats in a variety of ways. For example, images could be used as prompts for examination and critique of practices. The educators I interviewed also suggested that the images could be used to help student professionals develop their sensitivity to the forces and intensities that produce particular practices. Group interviews with student professionals suggested that the former happened spontaneously when students encountered and discussed such images, but that the latter might need deliberate facilitation or prompting. The thesis concludes with some recommendations for: (i) educators considering using such images in pre-service professional learning; (ii) professional developers considering using Twitter chats; and (iii) policy-makers involved in drafting guidelines for professionals’ use of social media

The influence of the gut microbiota on asthma in school-aged children and adults

Asthma is a common respiratory disease with a highly heterogeneous pathophysiology. The human gut microbiota, comprising of all the microorganisms that inhabit the gastrointestinal tract, is linked to the development of asthma and can alter airway inflammation in animal models. The idea that the gut microbiota can have bidirectional cross-talk with the lung, such as gut dysbiosis affecting lung disease, is termed the gut-lung axis. While the gut microbiota of early life has been an area of particular interest for asthma pathogenesis research, the effect of its taxonomic and functional composition after asthma diagnosis is less clear. This dissertation employs both amplicon sequencing followed by gnotobiotic mouse models (Chapter 2) and whole metagenomic shotgun sequencing (Chapter 3) to characterize human fecal microbiomes from school-aged children and adults with asthma. Investigation of the gut-lung axis in asthma later in life requires clinical studies with well-defined asthma inclusion criteria and strategic gnotobiotic experiments guided by taxonomic profiling of properly handled human samples. In Chapter 2, amplicon sequencing was used to identify population shifts between allergic moderate-to-severe asthma and healthy cohorts. Taxonomic shifts associated with asthma were observed even when accounting for other microbiome-modifying covariates such as age and race. Additionally, statistical modeling and gnotobiotic mouse models were used to identify taxa that could affect lung inflammation in vivo. A Naïve Bayes Classifier fit to a mixture model that accounts for the sparsity inherent to compositional data was built to optimize selection of samples from the human cohorts that would best represent a asthma-associated microbial community differences. The selected stool samples were then used to inoculate, or “humanize”, germ-free mouse gastrointestinal tracts before administration of allergen sensitization and challenge. Immunophenotyping, IgA-Seq, gut permeability assays, and whole genome sequencing of human fecal bacterial isolates uncovered an enterotoxigenic Bacteroides fragilis that affected lung inflammation in the context of intact human fecal communities as well as on its own in a monocolonization experiment. A PCR screen for the B. fragilis toxin (bft) across all human participants revealed that bft was more prevalent in the stool of people with asthma compared to that of healthy individuals. These findings suggest that the gut microbiota affects lung inflammation even after the diagnosis of asthma. While discovery of disease-modifying taxa is invaluable, taxonomic profiling by amplicon sequencing skips the genetic material that encodes a wealth of functional information about gut microbes. In Chapter 3, whole metagenomic shotgun sequencing is utilized on the human fecal samples from Chapter 2 to describe the genetic content of the entire gut microbiota, also called the “metagenome”. Read-based annotation revealed a shift in genetic content attributable to asthma even when accounting for covariates such as age and race. Metabolic pathway annotation suggested that fatty acid metabolism pathways, particularly those that result in long-chain fatty acid synthesis, are differentially abundant in the asthma cohort. Antibiotic resistance is a growing concern among physicians who provide asthma care and patients with asthma tend to require more antibiotic prescriptions than usual, particularly macrolide antibiotics. Antibiotic usage was tallied for all participants in this study and a higher proportion of the asthma cohort was found to have taken antibiotics in the past year compared to the healthy cohort. Subsequent profiling of antibiotic resistance genes (ARGs) in the gut metagenomes revealed an increased richness of ARGs in the asthma cohort while the total abundance of ARGs was not increased. Additionally, macrolide resistance markers were differentially abundant in the asthma cohort. Interestingly, the B. fragilis toxin, found to be more prevalent in the same asthma cohort in Chapter 2, was more likely to co-occur in the samples with ermF in the asthma cohort compared to the healthy cohort. Co-occurrence analysis of all ARGs and all virulence factors revealed a unique set of VF-ARG pairs in the asthma cohort compared to the healthy, together suggesting that the asthma gut microbiota offers opportunities for virulence factors and ARGs to co-occur that do not co-occur in healthy gut microbiota. The ermF-bft pair is particularly concerning given that bft has the potential to affect airway inflammation and macrolide resistance is already becoming a clinical problem for patients with asthma. In summary, this work characterizes metagenomic shifts in the gut microbiota associated with asthma, identifies a gut pathobiont that can alter lung inflammation, and reveals accumulation of antibiotic resistance genes in populations suffering from asthma. These findings provide needed insights into the gut-lung axis of asthma beyond diagnosis, and will guide development of gut-directed therapy for a frustratingly common disease

Factors Associated with Sexual Intercourse Among African-Born Adolescents in Southern California

Based on the theory of planned behavior the research aims were to: (a) ascertain how attitude, subjective norm, and perceived control predict intentions to engage in sexual intercourse among Black, African-born adolescents in Southern California; and (b) determine how behavioral beliefs, normative beliefs, and control beliefs predict attitude, subjective norm and perceived control. A questionnaire was developed based on focus group findings. One hundred and thirty-five adolescents aged 15 to 19 years completed the questionnaire. The strongest predictor of intention was attitude, then subjective norm. Enjoying sex, “wanting to be a parent” and to “keep sexual partners” predicted attitude. Educative, informative, cultural and faith based programs, if initiated may help African adolescents in Southern California

A protocol for a systematic review of randomised evaluations of strategies to improve recruitment of rural participants to randomised controlled trials

Peer reviewedPublisher PD

Factors Related to Youth Living with HIV Delaying Access to Care: The Role of Positive and Negative Social Network Influences on Health Seeking Behaviors

To explore factors related to youths’ delay in seeking care after an HIV diagnosis. Multivariate analyses were performed on 347 participants who were selected from a sample of 351 adolescents participating in a 1994-1996 survey among youth in four U.S. metropolitan cities. Key findings were that participants with prosocial peer behaviors took longer (34 days) to seek care than youth with poorer social engagement and excessive fibbing delayed seeking care (23 days). Potentially important findings suggest being female, older, having close peer networks, conduct problems, and certain housing settings may delay seeking care. Multivariate regression analyses indicate that later entry into medical care was observed among those with close social networks and behavioral characteristics related to delinquency

Barrier to autointegration factor blocks premature cell fusion and maintains adult muscle integrity in C. elegans

Barrier to autointegration factor (BAF) binds double-stranded DNA, selected histones, transcription regulators, lamins, and LAP2–emerin–MAN1 (LEM) domain proteins. During early Caenorhabditis elegans embryogenesis, BAF-1 is required to organize chromatin, capture segregated chromosomes within the nascent nuclear envelope, and assemble lamin and LEM domain proteins in reforming nuclei. In this study, we used C. elegans with a homozygous deletion of the baf-1 gene, which survives embryogenesis and larval stages, to report that BAF-1 regulates maturation and survival of the germline, cell migration, vulva formation, and the timing of seam cell fusion. In the seam cells, BAF-1 represses the expression of the EFF-1 fusogen protein, but fusion still occurs in C. elegans lacking both baf-1 and eff-1. This suggests the existence of an eff-1–independent mechanism for cell fusion. BAF-1 is also required to maintain the integrity of specific body wall muscles in adult animals, directly implicating BAF in the mechanism of human muscular dystrophies (laminopathies) caused by mutations in the BAF-binding proteins emerin and lamin A

Implementation of the Joint Duty Program at CIA: Analysis and Recommendations

This report assesses the strengths and weaknesses of the Joint Duty (JD) program as it is currently implemented at the CIA. Over the course of approximately six weeks, the Bush School 2012 Capstone interviewed - in-person and by phone - 160 CIA employees who completed a JD assignment. In assessing the qualitative and quantitative responses reported by personnel, we conclude that employees find value in the program, are well-integrated within their host agency, and achieve the program's mission of increasing employees' knowledge of other Intelligence Community agencies. Weaknesses hindering the program include: a disproportionately high number of employees choosing assignments at the Office of Director of National Intelligence (ODNI) and the National Reconnaissance Agency (NRO); insufficient manager guidance in selecting career-relevant assignments; failure to comply with regulations tasking agencies to maintain contact with their JD employees; employees experiencing significant difficulty returning to the CIA upon completion of their assignment; and inconsistent views regarding whether the program aids promotion potential.The Center for the Study of Intelligenc