Cartilage on the Move: Cartilage Lineage Tracing During Tadpole Metamorphosis

The reorganization of cranial cartilages during tadpole metamorphosis is a set of complex processes. The fates of larval cartilage-forming cells (chondrocytes) and sources of adult chondrocytes are largely unknown. Individual larval cranial cartilages may either degenerate or remodel, while many adult cartilages appear to form de novo during metamorphosis. Determining the extent to which adult chondrocytes/cartilages are derived from larval chondrocytes during metamorphosis requires new techniques in chondrocyte lineage tracing. We have developed two transgenic systems to label cartilage cells throughout the body with fluorescent proteins. One system strongly labels early tadpole cartilages only. The other system inducibly labels forming cartilages at any developmental stage. We examined cartilages of the skull (viscero- and neurocranium), and identified larval cartilages that either resorb or remodel into adult cartilages. Our data show that the adult otic capsules, tecti anterius and posterius, hyale, and portions of Meckel\u27s cartilage are derived from larval chondrocytes. Our data also suggest that most adult cartilages form de novo, though we cannot rule out the potential for extreme larval chondrocyte proliferation or de- and re-differentiation, which could dilute our fluorescent protein signal. The transgenic lineage tracing strategies developed here are the first examples of inducible, skeleton-specific, lineage tracing in Xenopus

Warm HCN, C2H2, and CO in the disk of GV Tau

We present the first high-resolution, ground-based observations of HCN and C2H2 toward the T Tauri binary star system GV Tau. We detected strong absorption due to HCN nu_3 and weak C2H2 (nu_3 and nu_2 + (nu_4 + nu_5)^0_+) absorption toward the primary (GV Tau S) but not the infrared companion. We also report CO column densities and rotational temperatures, and present abundances relative to CO of HCN/CO ~0.6% and C2H2/CO ~1.2% and an upper limit for CH4/CO < 0.37% toward GV Tau S. Neither HCN nor C2H2 were detected toward the infrared companion and results suggest that abundances may differ between the two sources.Comment: 23 pages, 6 figures, accepted by Ap

An examination of health inequities among college students by sexual orientation identity and sex

Background. Lesbian, gay, and bisexual (LGB) college students may have an increased number of health inequities compared to their heterosexual counterparts. However, to date, no research has provided a comprehensive examination of health-related factors by sexual orientation identity and sex among a national sample of college students. Thus, the purpose of this study was to examine physical, sexual, interpersonal relations/safety, and mental health inequities by sexual orientation identity and sex among a national sample of college students. Design and methods. Participants (n=39,767) completed the National College Health Assessment II during the fall 2008/spring 2009 academic year. Hierarchical binary logistic regression analyses were used to examine health inequities by sexual orientation identity and sex. Results. LGB students compared to heterosexual students, experienced multiple health inequities including higher rates of being verbally threatened and lower rates of physical activity and condom use. Conclusions. An understanding of health inequities experienced by LGB college students is critical as during these years of transition, students engage in protective (e.g., physical activity) and risky (e.g., lack of condom use) health behaviours, establishing habits that could last a lifetime. Future research should be used to design and implement targeted public health strategies and policies to reduce health inequities and improve health-related quality of life among LGB college students

Survey of Ices toward Massive Young Stellar Objects: I. OCS, CO, OCN−^-, and CH3_3OH

An important tracer of the origin and evolution of cometary ices is the comparison with ices found in dense clouds and towards Young Stellar Objects (YSOs). We present a survey of ices in the 2-5 micron spectra of 23 massive YSOs, taken with the NASA InfraRed Telescope Facility SpeX spectrometer. The 4.90 micron absorption band of OCS ice is detected in 20 sight-lines, more than five times the previously known detections. The absorption profile shows little variation and is consistent with OCS being embedded in CH3OH-rich ices, or proton-irradiated H$_2$S or SO$_2$-containing ices. The OCS column densities correlate well with those of CH$_3$OH and OCN$^-$, but not with H$_2$O and apolar CO ice. This association of OCS with CH$_3$OH and OCN$^-$ firmly establishes their formation location deep inside dense clouds or protostellar envelopes. The median composition of this ice phase towards massive YSOs, as a percentage of H$_2$O, is CO:CH$_3$OH:OCN$^-$:OCS=24:20:1.53:0.15. CS, due to its low abundance, is likely not the main precursor to OCS. Sulfurization of CO is likely needed, although the source of this sulfur is not well constrained. Compared to massive YSOs, low mass YSOs and dense clouds have similar CO and CH$_3$OH ice abundances, but less OCN$^-$ and more apolar CO, while OCS awaits detection. Comets tend to be under-abundant in carbon-bearing species, but this does not appear to be the case for OCS, perhaps signalling OCS production in protoplanetary disks.Comment: 35 pages, 18 figures. Published ApJ 941, 32. Updated arXiv title and publication informatio

THE ROLE OF THE NMDA RECEPTOR AND REVERSE SODIUM CALCIUM EXCHANGER IN CALCIUM DYSREGULATION IN GLUTAMATE-EXPOSED NEURONS

Indiana University-Purdue University Indianapolis (IUPUI)Introduction: During glutamate excitotoxicity, overstimulation of glutamate receptors leads to sustained elevation in cytosolic Ca2+ ([Ca2+]c), or delayed Ca2+ dysregulation (DCD), which is causally linked to cell death. There are two major hypothetical mechanisms for DCD: the continuous activation of N-methyl-D-aspartate-subtype of the ionotropic glutamate receptors (NMDAR) and the reversal of the plasmalemmal Na+/Ca2+ exchanger. However, the contribution of each of these mechanisms in DCD is not completely established. Major results: Neurons exposed to excitotoxic glutamate produced DCD, an increase in cytosolic Na+ ([Na+]c), and plasma membrane depolarization. MK801 and memantine, noncompetitive NMDAR inhibitors, added after glutamate, completely prevented DCD; however AP-5, a competitive NMDAR inhibitor, failed to do so. The NMDAR inhibitors had no effect on lowering elevated [Na+]c or on restoring plasma membrane potential, which are conditions suggesting NCXrev could be involved. In experiments inducing NCXrev, MK801 and memantine completely inhibited Ca2+ dysregulation after glutamate while AP-5 did not. Inhibition of NCXrev, either with KB-R7943 or by preventing the increase in [Na+]c, failed to avert DCD. However, NCXrev inhibition combined with NMDAR blocked by AP-5 completely prevented DCD. Overall, these data suggested that both NMDAR and NCXrev are essential for glutamate-induced DCD, and inhibition of only one mechanism is insufficient to prevent collapse of calcium homeostasis. Based on the data above, we investigated a NMDA receptor antagonist currently in clinical trials for reducing the effects of glutamate excitotoxicity, ifenprodil. Ifenprodil is an activity-dependent, NMDAR inhibitor selective for the NR2B subunit. We found that ifenprodil not only inhibited the NR2B-specific NMDAR, but also inhibited NCXrev. If ifenprodil is combined with PEAQX, a NMDAR inhibitor selective for the NR2A subunit, low concentrations of both inhibitors completely prevent DCD. Conclusion: The inhibition of a single Ca2+ influx mechanism is insufficient in preventing DCD, which requires simultaneous inhibition of both the NMDAR and NCXrev. These findings are critical for the correct interpretation of the experimental results obtained with these inhibitors and for better understanding of their neuroprotective actions

‘It’s where I belong’: what does it mean to age in place from the perspective of people aged 80 and above? A longitudinal qualitative study (wave one)

\ua9 The Author(s) 2024.Background: Most people want to remain at home as they age. Ageing in place – remaining at home and connected to the community – is a national and international policy priority; however, to better understand how policy might be implemented, a more nuanced understanding is required about older adults’ lived experiences of ageing in place, especially the experiences of those aged 80 and above. Objective: To describe and explore the social processes which enable ageing in place from the perspective of community-dwelling older people (80+). Methods: Forty-six respondents (80–100+ years) participated in the first wave of a longitudinal qualitative study set in North East England. Semi-structured interviews were conducted in participants’ homes between June 2022 and January 2023. Interviews were analysed using reflexive thematic analysis. Results: Participants positioned their homes as a place of freedom and as the antithesis of a ‘care home’. Remaining in place was important for all participants; a key priority for them was to remain physically active to enable this. However, many participants faced significant hurdles to remaining in place. These were primarily related to health and mobility issues. Some participants were able to overcome such barriers by drawing on financial resources and available social networks. Conclusion: The home is central to understanding older peoples’ (80+) experiences of ageing. In a socio-political context which promotes ageing in place, the social factors shaping experiences of ageing in place must be considered. This involves attending to the challenges of later life, particularly health and especially mobility and physical function. Currently, those with resources (social and economic) are better equipped to respond to such challenges, thus potentially exacerbating widening inequalities in ageing. By foregrounding the perspectives of those ageing in place alongside social factors shaping their experiences, our study has important implications for policy and health and social care. We show that a more equitable allocation of resources is vital to fulfil the ageing in place policy agenda. Furthermore, we highlight a need to recognise commitments to ageing in place displayed by people aged 80 and above, especially when remaining in place becomes difficult to achieve

Erratum: Warm HCN, C2H2, and CO in the Disk of GV Tau\u27\u27

This is an Erratum for the article 2007 ApJ 660 157

Embarking as Captain of the Ship for the Curriculum Committee

This commentary examines the curriculum chair’s responsibilities and discusses considerations when assuming this role, using a captain of the ship metaphor. From knowing the crew to managing a diverse set of responsibilities, the path to becoming an effective chair is challenging and each captain’s stripe must be earned. Advice is provided to assist with understanding the curriculum and governance processes, as well as the chair’s various roles and professional development. The need for both leadership and management is also emphasized

Patient and public involvement in care home research: Reflections on the how and why of involving patient and public involvement partners in qualitative data analysis and interpretation

Background There is limited evidence for the impact of involving patients and the public (PPI) in health research. Descriptions of the PPI process are seldom included in publications, particularly data analysis, yet an understanding of processes and impacts of PPI is essential if its contribution to research is to be evaluated. Objective To describe the ‘how’ of PPI in qualitative data analysis and critically reflect on potential impact. Methods We focus on the development and critical reflection of our step-by-step approach to collaborative qualitative data analysis (through a series of analysis workshops) in a specific care home study, and our long-term engagement model with patients and the public (termed PPI partners). Results An open access PPI group, with multiple events over time, sustained broad interest in care home research. Recordings of interview clips, role-play of interview excerpts and written theme summaries were used in workshops to facilitate PPI partner engagement with data analysis in a specific study. PPI resulted in changes to data interpretation and was perceived to make the research process accessible. We reflect on the challenge of judging the benefits of PPI and presenting PPI in research publications for critical commentary. Conclusions Patient and public involvement partners who are actively engaged with data analysis can positively influence research studies. However, guidance for researchers is needed on approaches to PPI, including appropriate levels and methods for evaluation. Without more systematic approaches, we argue that it is impossible to know whether PPI represents good use of resources and is generating a real impact