Physical Processes in Star Formation

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00693-8.Star formation is a complex multi-scale phenomenon that is of significant importance for astrophysics in general. Stars and star formation are key pillars in observational astronomy from local star forming regions in the Milky Way up to high-redshift galaxies. From a theoretical perspective, star formation and feedback processes (radiation, winds, and supernovae) play a pivotal role in advancing our understanding of the physical processes at work, both individually and of their interactions. In this review we will give an overview of the main processes that are important for the understanding of star formation. We start with an observationally motivated view on star formation from a global perspective and outline the general paradigm of the life-cycle of molecular clouds, in which star formation is the key process to close the cycle. After that we focus on the thermal and chemical aspects in star forming regions, discuss turbulence and magnetic fields as well as gravitational forces. Finally, we review the most important stellar feedback mechanisms.Peer reviewedFinal Accepted Versio

Barriers and facilitators to screening for malnutrition by community nurses: a qualitative study

BackgroundA substantial proportion of individuals who live in community settings in the UK experience malnutrition. Routine screening for malnutrition by healthcare practitioners has been recommended in many regions. The present study aimed to understand community nurses' perceptions of barriers and facilitators to undertaking nutritional screening.MethodsA qualitative study was undertaken with a purposive sample of community nurses working in one UK healthcare organisation. Semi-structured interviews were used to elicit perceptions of barriers and facilitators. Interviews were digitally recorded, anonymised and transcribed. Initial codes were assigned for salient constructs identified in the transcripts, refined by grouping, and a thematic list was developed.ResultsTwenty district nurses and community matrons were interviewed at which time saturation of the data was achieved. Six themes emerged: supportive organisational culture, time and resource to screen and intervene, ease and acceptability of the screening tool, professional judgement as good as screening, the need for training and sharing good practice, and enhancing communication between care settings.ConclusionsThe findings of the present study suggest that screening is more likely to be completed where an organisation is perceived to have a clear expectation that it is undertaken and also demonstrates this through training and availability of resources. The need for a process or tool that nurses find easy to use and relevant to their practice area was highlighted. Further research should examine the effect of the use of a nutritional screening tool by community nurses on nutritional care planning and intervention

A ratiometric fluorescent probe for assessing mitochondrial phospholipid peroxidation within living cells.

Item does not contain fulltextMitochondrial oxidative damage contributes to a wide range of pathologies, and lipid peroxidation of the mitochondrial inner membrane is a major component of this disruption. However, despite its importance, there are no methods to assess mitochondrial lipid peroxidation within cells specifically. To address this unmet need we have developed a ratiometric, fluorescent, mitochondria-targeted lipid peroxidation probe, MitoPerOx. This compound is derived from the C11-BODIPY(581/591) probe, which contains a boron dipyromethane difluoride (BODIPY) fluorophore conjugated via a dienyl link to a phenyl group. In response to lipid peroxidation the fluorescence emission maximum shifts from approximately 590 to approximately 520nm. To target this probe to the matrix-facing surface of the mitochondrial inner membrane we attached a triphenylphosphonium lipophilic cation, which leads to its selective uptake into mitochondria in cells, driven by the mitochondrial membrane potential. Here we report on the development and characterization of MitoPerOx. We found that MitoPerOx was taken up very rapidly into mitochondria within cells, where it responded to changes in mitochondrial lipid peroxidation that could be measured by fluorimetry, confocal microscopy, and epifluorescence live cell imaging. Importantly, the peroxidation-sensitive change in fluorescence at 520nm relative to that at 590nm enabled the use of the probe as a ratiometric fluorescent probe, greatly facilitating assessment of mitochondrial lipid peroxidation in cells