Planetary nebulae after common-envelope phases initiated by low-mass red giants

It is likely that at least some planetary nebulae are composed of matter which was ejected from a binary star system during common-envelope (CE) evolution. For these planetary nebulae the ionizing component is the hot and luminous remnant of a giant which had its envelope ejected by a companion in the process of spiralling-in to its current short-period orbit. A large fraction of CE phases which end with ejection of the envelope are thought to be initiated by low-mass red giants, giants with inert, degenerate helium cores. We discuss the possible end-of-CE structures of such stars and their subsequent evolution to investigate for which structures planetary nebulae are formed. We assume that a planetary nebula forms if the remnant reaches an effective temperature greater than 30 kK within 10^4 yr of ejecting its envelope. We assume that the composition profile is unchanged during the CE phase so that possible remnant structures are parametrized by the end-of-CE core mass, envelope mass and entropy profile. We find that planetary nebulae are expected in post-CE systems with core masses greater than about 0.3 solar masses if remnants end the CE phase in thermal equilibrium. We show that whether the remnant undergoes a pre-white dwarf plateau phase depends on the prescribed end-of-CE envelope mass. Thus, observing a young post-CE system would constrain the end-of CE envelope mass and post-CE evolution.Comment: Published in MNRAS. 12 pages, 12 figures. Minor changes to match published versio

Rethinking Leadership: The Changing Role of Principal Supervisors

In the fall of 2012, the Council of the Great City Schools launched a two-part study of the ways principal supervisors are selected, supported, and evaluated in major school districts across the country. The first part involved a survey administered to district staff serving as principal supervisors in the fall of 2012. The second part of the study involved site visits to the six districts participating in The Wallace Foundation's Principal Pipeline Initiative -- Charlotte-Mecklenburg Schools, Denver Public Schools, Gwinnett County Public Schools, Hillsborough County Public Schools, the New York City Department of Education, and Prince George's County Public Schools. This report provides a summary of findings from both the survey and site visits. Part I presents a description of the organizational structure and general features of the various principal supervisory systems, including the roles, selection, deployment, staffing, professional development, and evaluation of principal supervisors, as well as the preparation, selection, support, and evaluation of principals. Part II provides recommendations for building more effective principal supervisory systems. Based on the survey results and observations from the site visits, these recommendations identify those structures and practices that are most likely to result in stronger school leaders and higher student achievement

The Asymptotic Behaviour of the Residual Sum of Squares in Models with Multiple Break Points

Models with multiple discrete breaks in parameters are usually estimated via least squares. This paper, first, derives the asymptotic expectation of the residual sum of squares and shows that the number of estimated break points and the number of regression parameters affect the expectation differently. Second, we propose a statistic for testing the joint hypothesis that the breaks occur at specified points in the sample. Our analytical results cover models estimated by the ordinary, nonlinear, and two-stage least squares. An application to U.S. monetary policy rejects the assumption that breaks are associated with changes in the chair of the Fed

TCR Convergence in Individuals Treated With Immune Checkpoint Inhibition for Cancer.

Tumor antigen-driven selection may expand T cells having T cell receptors (TCRs) of shared antigen specificity but different amino acid or nucleotide sequence in a process known as TCR convergence. Substitution sequencing errors introduced by TCRβ (TCRB) repertoire sequencing may create artifacts resembling TCR convergence. Given the anticipated differences in substitution error rates across different next-generation sequencing platforms, the choice of platform could be consequential. To test this, we performed TCRB sequencing on the same peripheral blood mononuclear cells (PBMC) from individuals with cancer receiving anti-CTLA-4 or anti-PD-1 using an Illumina-based approach (Sequenta) and an Ion Torrent-based approach (Oncomine TCRB-LR). While both approaches found similar TCR diversity, clonality, and clonal overlap, we found that Illumina-based sequencing resulted in higher TCR convergence than with the Ion Torrent approach. To build upon this initial observation we conducted a systematic comparison of Illumina-based TCRB sequencing assays, including those employing molecular barcodes, with the Oncomine assay, revealing differences in the frequency of convergent events, purportedly artifactual rearrangements, and sensitivity of detection. Finally, we applied the Ion Torrent-based approach to evaluate clonality and convergence in a cohort of individuals receiving anti-CTLA-4 blockade for cancer. We found that clonality and convergence independently predicted response and could be combined to improve the accuracy of a logistic regression classifier. These results demonstrate the importance of the sequencing platform in assessing TCRB convergence

Participatory research meets validated outcome measures:tensions in the co-production of social care evaluation

Funding for care service research is increasingly subject to the satisfaction of two requirements: public involvement; and adoption of validated outcome tools. This study identifies competing paradigms within these requirements and reveals significant challenges faced by researchers who seek to satisfy them. The focus here is on a study co-produced between academic researchers and people with experience of adult social care services. It examines to what extent research studies can conduct high quality public involvement and genuine co-production of knowledge, whilst attempting to produce quantifiable outcome scores. Findings add to debate around how to incorporate diverse perspectives in research which may draw on incommensurate accounts of validity and reliability. Findings also highlight constructive attempts by academic and co-researchers to make the combination of approaches work in the field. These small scale acts of researcher agency indicate some scope to combine the two approaches in future research studies. However conclusions foreground the importance of broader awareness of how tensions and power imbalances related to this combination of approaches play out in social policy research practice

Training Counselors Using Virtual Reality

Virtual reality (VR) has the potential to expand experiential learning opportunities in counselor education. This article discusses how semi- and immersive VR can provide students a diverse range of experiences to increase both counseling skill and empathy development for clients with a myriad of identities, diagnoses, and presenting counseling issues. Suggestions and implications for counselor education are discussed

Co-research with older people:perspectives on impact

Although research in partnership with older people has been slower to develop than that with some other service user ‘groups’, there are a growing number of health and social care studies that have involved older people as co-researchers. We build on this existing evidence by addressing two key areas. First, despite the growth of participatory research with older people generally, some groups tend to be excluded. We focus particularly on a project in which older people with dementia and older people from a black and minority ethnic community were involved as co-researchers. They worked with academic researchers in all stages of the research process, exploring other older people’s experiences of transitions between care services. Second, recent literature suggests a lack of critical evaluation of involvement, arguing that researchers tend to emphasise the positives on the basis of retrospective narrative accounts of the process, rather than critically appraising the impact of involvement. This article offers a critical account of the impact of a participatory approach at different stages of a research project, evaluating this from the perspective of different stakeholders. In so doing, we engage with incisive critiques which claim that, far from empowering service users, much service user involvement activity contributes to their oppression. We conclude that participatory research with marginalised older people has the potential to achieve meaningful change at both individual and social levels. However, in view of its dangers and limitations, we argue the need for the impact of participatory research to be carefully evaluated from the perspectives of all parties in the process. </jats:p