Quantification of Risk for USAF Fire and Emergency Services Flights as a Result of Shortage in Manpower

The United States Air Force (USAF) is currently experiencing a period of high operations tempo and overseas deployments have become frequent. These deployments will leave home installations short manned. Some amount of risk is incurred by the home installation as a result of the short manning. For an organization, such as an USAF Fire and Emergency Services (FES) flight, whose primary responsibility is the protection of life and property, the incurred risk could be catastrophic. Still no attempt has been made to quantify risk in terms of manpower for the USAF FES flights. The primary purpose of this research was to develop and validate a methodology to quantify risk in terms of manpower for FES flights. This research develops a decision tool to provide insight to FES Fire Chiefs on the risk associated with specific manpower decisions. The methodology was validated using data from Dyess Air Force Base FES flight. A secondary goal of the research was to determine a cost/benefit relationship between the risk level and the cost to backfill deployed firefighter positions with contract labor. The result was a decision tree model and pareto optimal graphs for the risk to manpower level and the cost/benefit relationship

Effect of Preventive Home Visits by a Nurse on the Outcomes of Frail Elderly People in the Community: a randomized controlled trial

Background: Timely recognition and prevention of health problems among elderly people have been shown to improve their health. In this randomized controlled trial the authors examined the impact of preventive home visits by a nurse compared with usual care on the outcomes of frail elderly people living in the community. Methods: A screening questionnaire identified eligible participants (those aged 70 years or more at risk of sudden deterioration in health). Those randomly assigned to the visiting nurse group were assessed and followed up in their homes for 14 months. The primary outcome measure was the combined rate of deaths and admissions to an institution, and the secondary outcome measure the rate of health services utilization, during the 14 months; these rates were determined through a medical chart audit by a research nurse who was blind to group allocation. Results: The questionnaire was mailed to 415 elderly people, of whom 369 (88.9%) responded. Of these, 198 (53.7%) were eligible, and 142 consented to participate and were randomly assigned to either the visiting nurse group (73) or the usual care group (69). The combined rate of deaths and admissions to an institution was 10.0% in the visiting nurse group and 5.8% in the usual care group (p = 0.52). The rate of health services utilization did not differ significantly between the 2 groups. Influenza and pneumonia vaccination rates were significantly higher in the visiting nurse group (90.1% and 81.9%) than in the usual care group (53.0% and 0%) (p \u3c 0.001). Interpretation: The trial failed to show any effect of a visiting nurse other than vastly improved vaccination coverage

Screening Seniors for Risk of Functional Decline: Results of a Survey in Family Practice

To measure functional status, determine risk of functional decline and assess consistency between responses and standardized instruments. Design: A mailed survey which measured functional impairment, recent hospitalization and bereavement. A positive response on at least one of these factors indicated that the individual was “at risk” for functional decline. A random sample (n=73) of “at risk” subjects (specifically, family practice patients aged 70 and older) were assessed by a nurse. Results: The response rate was 89% (369/415), 59% of seniors were female and the mean age was 77.1 (SD=5.5) years. Self-reported risk, based on activities of daily living (ADLs), was associated with impairment in at least one basic ADL (p\u3c0.0005) using a standardized instrument. The positive predictive value of the survey for ADL impairment was 65%. Conclusion: Response to a mailed survey was high and self-reported ADL risks were consistent with findings from standardized assessment tools

Computational Design To Reduce Conformational Flexibility and Aggregation Rates of an Antibody Fab Fragment

Computationally-guided semi-rational design has significant potential for improving the aggregation kinetics of protein biopharmaceuticals. While improvement in the global conformational stability can stabilise proteins to aggregation under some conditions, previous studies suggest that such an approach is limited because thermal transition temperatures (Tm) and the fraction of protein unfolded (fT) tend to only correlate with aggregation kinetics where the protein is incubated at temperatures approaching the Tm. This is because under these conditions, aggregation from globally unfolded protein becomes dominant. However, under native conditions, the aggregation kinetics are presumed to be dependent on local structural fluctuations or partial unfolding of the native state, that reveal regions of high propensity to form protein-protein interactions that lead to aggregation. In this work, we have targeted the design of stabilising mutations to regions of the A33 Fab surface structure, that were predicted to be more flexible. This Fab already has high global stability, and global unfolding is not the main cause of aggregation under most conditions. Therefore, the aim was to reduce the conformational flexibility and entropy of the native protein at various locations, and thus identify which of those regions has the greatest influence on the aggregation kinetics. Highly dynamic regions of structure were identified through both molecular dynamics simulation, and B-factor analysis of related X-ray crystal structures. The most flexible residues were mutated into more stable variants, as predicted by Rosetta, which evaluates the ΔΔGND for each potential point mutation. Additional destabilising variants were prepared as controls to evaluate the prediction accuracy, and also to assess the general influence of conformational stability on aggregation kinetics. The thermal conformational stability, and aggregation rates of eighteen variants at 65 °C, were each examined at pH 4, 200 mM ionic strength, under which conditions the initial wild-type protein was <5% unfolded. Variants with decreased Tm values led to more rapid aggregation due to an increase in the fraction of protein unfolded under the conditions studied. As expected, no significant improvements were observed in the global conformational stability as measured by Tm. However, six of the twelve stable variants led to an increase in the cooperativity of unfolding, consistent with lower conformational flexibility and entropy in the native ensemble. Three of these had 5-11% lower aggregation rates, and their structural clustering indicated that the local dynamics of the C-terminus of the heavy chain had a role in influencing the aggregation rate

Lyophilization to enable distribution of ChAdOx1 and ChAdOx2 adenovirus-vectored vaccines without refrigeration

Distribution of vaccines which require refrigerated or frozen storage can be challenging and expensive. The adenovirus vector platform has been widely used for COVID-19 vaccines while several further candidate vaccines using the platform are in clinical development. In current liquid formulations, adenoviruses require distribution at 2-8 °C. The development of formulations suitable for ambient temperature distribution would be advantageous. Previous peer-reviewed reports of adenovirus lyophilization are relatively limited. Here, we report the development of a formulation and process for lyophilization of simian adenovirus-vectored vaccines based on the ChAdOx1 platform. We describe the iterative selection of excipients using a design of experiments approach, and iterative cycle improvement to achieve both preservation of potency and satisfactory cake appearance. The resulting method achieved in-process infectivity titre loss of around 50%. After drying, there was negligible further loss over a month at 30 °C. Around 30% of the predrying infectivity remained after a month at 45 °C. This performance is likely to be suitable for 'last leg' distribution at ambient temperature. This work may also facilitate the development of other product presentations using dried simian adenovirus-vectored vaccines

Complete analysis of the H5 hemagglutinin and N8 neuraminidase phylogenetic trees reveals that the H5N8 subtype has been produced by multiple reassortment events

The analysis of the complete H5 hemagglutinin and H8 neuraminidase phylogenetic trees presented in this paper shows that the H5N8 avian influenza has been generated by multiple reassortment events. The H5N8 strain does not have a single origin and is produced when the H5 hemagglutinin and N8 neuraminidase re-assort from other H5 and N8 containing strains. While it was known that there had been a re-assortment to incorporate the Guangdong H5 hemagglutinin at the start of the Korean outbreak, the results show that there have also been multiple reassortment events amongst the non-Korean sequences

Label-free segmentation of co-cultured cells on a nanotopographical gradient

The function and fate of cells is influenced by many different factors, one of which is surface topography of the support culture substrate. Systematic studies of nanotopography and cell response have typically been limited to single cell types and a small set of topographical variations. Here, we show a radical expansion of experimental throughput using automated detection, measurement, and classification of co-cultured cells on a nanopillar array where feature height changes continuously from planar to 250 nm over 9 mm. Individual cells are identified and characterized by more than 200 descriptors, which are used to construct a set of rules for label-free segmentation into individual cell types. Using this approach we can achieve label-free segmentation with 84% confidence across large image data sets and suggest optimized surface parameters for nanostructuring of implant devices such as vascular stents

Second generation engineering of transketolase for polar aromatic aldehyde substrates

Transketolase has significant industrial potential for the asymmetric synthesis of carboncarbon bonds with new chiral centres. Variants evolved on propanal were found previously with nascent activity on polar aromatic aldehydes 3-formylbenzoic acid (3-FBA), 4-formylbenzoic acid (4-FBA), and 3-hydroxybenzaldehyde (3-HBA), suggesting a potential novel route to analogues of chloramphenicol. Here we evolved improved transketolase activities towards aromatic aldehydes, by saturation mutagenesis of two active-site residues (R358 and S385), predicted to interact with the aromatic substituents. S385 variants selectively controlled the aromatic substrate preference, with up to 13-fold enhanced activities, and KM values comparable to those of natural substrates with wild-type transketolase. S385E even completely removed the substrate inhibition for 3-FBA, observed in all previous variants. The mechanisms of catalytic improvement were both mutation type and substrate dependent. S385E improved 3-FBA activity via kcat, but reduced 4-FBA activity via KM. Conversely, S385Y/T improved 3-FBA activity via KM and 4-FBA activity via kcat. This suggested that both substrate proximity and active-site orientation are very sensitive to mutation. Comparison of all variant activities on each substrate indicated different binding modes for the three aromatic substrates, supported by computational docking. This highlights a potential divergence in the evolution of different substrate specificities, with implications for enzyme engineering