Elucidating the biological role of actin cytoskeletal proteins in the budding yeast saccharomyces cerevisiae

The dynamic, co-ordinated remodelling of the actin cytoskeleton is attributed to the interaction of actin with a wide variety of actin regulating proteins. The remodelling of actin is central to many cellular processes including endocytic uptake, polarisation of growth, cell motility, and is important for the ability of cells to respond to many intracellular and extracellular signals. Therefore, the study of individual actin regulating proteins enables a greater understanding of the complex overall control of the actin network and many cellular processes. Sla1p is an endocytic adaptor protein with several known roles in the cytoplasm, which include linking proteins involved in the early stages of endocytic uptake with those required for the actin polymerisation at endocytic sites. The data presented in this thesis however details the nuclear localisation of Sla1p. In addition to this initial observation, further analysis has allowed the proposal of a mechanism for the nuclear translocation of Sla1p. This was achieved by analysis of potential nuclear transport signals in wild-type and sla1 mutants, consideration of phosphorylatory mechanisms, and by detailed studies of nuclear transport receptor mutants. Finally, results of microarray analysis undertaken between wild-type and sla1 mutant strains were used to elucidate potential roles of nuclear Sla1p. These studies suggest that Sla1p localises both to the cytoplasm and the nucleus in S. cerevisiae and that its activity and cellular localisation may be regulated primarily through phosphorylation. The key to the dynamic remodelling of the actin cytoskeleton is the coordinated control of filament nucleation, polymerisation and disassembly. Data presented in this thesis demonstrates the association of the cortical patch protein Ysc84p with actin filaments, and the ability of Ysc84p to both sever and cap these filaments in vitro. A possible regulatory mechanism for the protein is also considered. Additionally, a Ysc84p homologue is localised to dynamic actin structures in mammalian cells and studies suggest that this protein may have a similar actin regulatory mechanism. These studies therefore suggest an exciting role for the cortical patch protein Ysc84p in the regulated control of branched actin filaments in S. cerevisiae

Fragmentation dynamics of the ethyl bromide and ethyl iodide cations: a velocity-map imaging study

The photodissociation dynamics of ethyl bromide and ethyl iodide cations (C2H5Br+ and C2H5I+) have been studied. Ethyl halide cations were formed through vacuum ultraviolet (VUV) photoionization of the respective neutral parent molecules at 118.2 nm, and were photolysed at a number of ultraviolet (UV) photolysis wavelengths, including 355 nm and wavelengths in the range from 236 to 266 nm. Time-of-flight mass spectra and velocity-map images have been acquired for all fragment ions and for ground (Br) and spin–orbit excited (Br*) bromine atom products, allowing multiple fragmentation pathways to be investigated. The experimental studies are complemented by spin–orbit resolved ab initio calculations of cuts through the potential energy surfaces (along the RC–Br/I stretch coordinate) for the ground and first few excited states of the respective cations. Analysis of the velocity-map images indicates that photoexcited C2H5Br+ cations undergo prompt C–Br bond fission to form predominantly C2H5+ + Br* products with a near-limiting ‘parallel’ recoil velocity distribution. The observed C2H3+ + H2 + Br product channel is thought to arise via unimolecular decay of highly internally excited C2H5+ products formed following radiationless transfer from the initial excited state populated by photon absorption. Broadly similar behaviour is observed in the case of C2H5I+, along with an additional energetically accessible C–I bond fission channel to form C2H5 + I+ products. HX (X = Br, I) elimination from the highly internally excited C2H5X+ cation is deemed the most probable route to forming the C2H4+ fragment ions observed from both cations. Finally, both ethyl halide cations also show evidence of a minor C–C bond fission process to form CH2X+ + CH3 products

Hot of Not: Physiological versus Meteorological Heatwaves-Support for a Mean Temperature Threshold

The aim of this study was to determine whether a revised heat warning threshold provides an enhanced predictive tool for increases in Emergency Department heat-related presentations in Canberra, Australia. All Emergency Department triage records containing the word "heat", as well as those diagnosing a heat related illness for the summer periods 2013/2014, 2014/2015, and 2015/2016 were searched. Then a medical record review was conducted to confirm that the patient's presentation was related to environmental heat, which was defined by the final clinical diagnosis, presentation complaint and details of the patient's treatment. Researchers then compared this presentation data, to a mean threshold formula. The mean threshold formula included the past three consecutive daily mean temperatures and the last measured temperature upon presentation. This formula was designed to take into account the variance of night-time lows, with concurrent daily ambient temperatures, and was used to determine whether there was a correlation between heat-related presentations and increasing mean temperatures. Heat-related presentations appeared to occur when the mean threshold temperature reached 25 °C (77 °F), with significant increases when the mean threshold reached 30 °C (86 °F). These results confirm that a mean temperature of 30 °C corresponds to a relevant local public health heat-related threat

Characterisation of a pucBA deletion mutant from Rhodopseudomonas palustris lacking all but the pucBAd genes

Rhodopseudomonas palustris is a species of purple photosynthetic bacteria that has a multigene family of puc genes that encode the alpha and beta apoproteins, which form the LH2 complexes. A genetic dissection strategy has been adopted in order to try and understand which spectroscopic form of LH2 these different genes produce. This paper presents a characterisation of one of the deletion mutants generated in this program, the pucBAd only mutant. This mutant produces an unusual spectroscopic form of LH2 that only has a single large NIR absorption band at 800 nm. Spectroscopic and pigment analyses on this complex suggest that it has basically a similar overall structure as that of the wild-type HL LH2 complex. The mutant has the unique phenotype where the mutant LH2 complex is only produced when cells are grown at LL. At HL the mutant only produces the LH1-RC core complex

Changes in body composition after initiation of haemodialysis: A retrospective cohort study.

Malnutrition is common in haemodialysis (HD) and is linked to poor outcomes. This study aimed to describe changes in body composition after the initiation of HD and investigate whether any routinely collected parameters were associated with these changes. The study cohort came from the HD population of a single centre between 2009 and 2014. Body composition measurements were obtained from a database of bioimpedance results using the Body Composition Monitor (BCM), while demographics and laboratory values came from the renal unit database. Primary outcomes were changes in normohydration weight, lean tissue mass and adipose tissue mass over the two years after HD initiation. A total of 299 patients were included in the primary analyses, showing an increase in adipose tissue, loss of lean tissue and no significant change in normohydration weight. None of the routinely collected parameters were associated with the lean tissue changes. Loss of lean tissue over the first year of dialysis was associated with increased mortality. The results showing loss of lean tissue that is not limited to those traditionally assumed to be at high risk supports interventions to maintain or improve lean tissue as soon as possible after the initiation of HD. It highlights the importance of monitoring nutrition and the potential for routine use of bioimpedance

SPACE FOR COPD© delivered as a maintenance programme on Pulmonary Rehabilitation discharge::protocol of a randomised controlled trial evaluating the long-term effects on exercise tolerance and mental well-being

Introduction The benefits achieved during pulmonary rehabilitation (PR) are known to be sustained for 6–12 months after the initial programme. Several maintenance trials have been conducted but were heterogeneous in terms of duration, frequency and labour cost. There is no consensus on one best strategy. SPACE FOR COPD (Self-management Programme of Activity, Coping and Education for Chronic Obstructive Pulmonary Disease) is a home-based self-management programme, which has been shown previously to be effective in primary and secondary care settings and is to be tested here as a maintenance programme. The aim is to evaluate the efficacy of the SPACE FOR COPD programme (manual and group sessions), on exercise tolerance and mental well-being, compared with usual care following PR in patients with COPD. Methods and analysis A prospective, multicentre, single-blinded randomised controlled trial requiring 116 participants with a clinical diagnosis of COPD who have finished PR within 4 weeks will be randomised 1:1 to either a usual care group or a SPACE FOR COPD programme group. The intervention comprises a home-based manual and 4, 2-hour group sessions adopting motivational interviewing techniques over 12 months. The primary outcome is endurance capacity measured by the Endurance Shuttle Walking Test at 12 months. Secondary outcomes are: maximal exercise capacity, health-related quality of life, mood, patient activation, physical activity, lung function and healthcare costs. The measures will be taken at baseline, 6 and 12 months. Patient interviews and staff focus groups will be conducted to explore barriers, facilitators and views about the intervention at the end of the study. A framework analysis will be used for the interpretation of qualitative data. Ethics and dissemination The trial was granted ethical approval from Health Research Authority and Health and Care Research Wales (HCRW19/EM/0267 on 10 October 2019). Results will be made available to all stakeholders through a dissemination event, conferences and peer-reviewed publications. Trial registration number ISRCTN30110012

Equity and the financial costs of informal caregiving in palliative care: a critical debate.

BACKGROUND: Informal caregivers represent the foundation of the palliative care workforce and are the main providers of end of life care. Financial pressures are among the most serious concerns for many carers and the financial burden of end of life caregiving can be substantial. METHODS: The aim of this critical debate paper was to review and critique some of the key evidence on the financial costs of informal caregiving and describe how these costs represent an equity issue in palliative care. RESULTS: The financial costs of informal caregiving at the end of life can be significant and include carer time costs, out of pocket costs and employment related costs. Financial burden is associated with a range of negative outcomes for both patient and carer. Evidence suggests that the financial costs of caring are not distributed equitably. Sources of inequity are reflective of those influencing access to specialist palliative care and include diagnosis (cancer vs non-cancer), socio-economic status, gender, cultural and ethnic identity, and employment status. Effects of intersectionality and the cumulative effect of multiple risk factors are also a consideration. CONCLUSIONS: Various groups of informal end of life carers are systematically disadvantaged financially. Addressing these, and other, determinants of end of life care is central to a public health approach to palliative care that fully recognises the value of carers. Further research exploring these areas of inequity in more depth and gaining a more detailed understanding of what influences financial burden is required to take the next steps towards meeting this aspiration. We will address the conclusions and recommendations we have made in this paper through the work of our recently established European Association of Palliative Care (EAPC) Taskforce on the financial costs of family caregiving

The effects of age and sex on mandibular bone graft donor sites

Objectives Intra‐oral bone grafting relies on 3‐Dimensional understanding of mandibular anatomy. This study assessed the bone volume at the two most common intra‐oral bone harvesting sites, the retromandibular and symphyseal regions, and assessed the impact of age and sex on the available bone at these sites. Materials and Methods Demographic and anatomical data were collected from Cone Beam Computer Tomographs (CBCT’s) of 200 randomly selected, fully dentate participants (100 male / 100 female) between the ages of 24 and 86 years. Statistical analysis was conducted with SPSS V25, using ANalysis of COVAriance (ANCOVA) to determine the effects of age and sex on the measurements at the donor sites. Results At retromandibular sites, women have a broader alveolar crest with a narrower mandible at the level of the IDC. There is a statistically significant difference, between the sexes, in bone width from the buccal cortex to the IDC. Men have a significantly greater distance from the outer buccal plate to the IDC. There is no difference in any measured dimension at the symphyseal region. There is a statistically significant reduction in bone volume with increasing age at both mandibular sites of 0.03 ‐ 0.05mm annually, irrespective of tooth loss. Conclusion Anatomical variability due to sex and bone reduction with age are both important findings in dental implantology, which must be considered when treatment planning and selecting bone grafting sites in the mandible. This study reinforces the importance of pre‐operative CBCT in planning bone grafting procedures