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Purpose The purpose of this paper is to present a case study tracking the development and engagement of a group of experts by experience (The Independent Futures (IF) Group) who provided a lived experience voice to the Bristol Golden Key (GK) partnership within the Fulfilling Lives programme. The case study reports the genesis and impact of the group, as well as the facilitators of impact and experiences of the group members and those they worked in partnership with. Design/methodology/approach The research adopted an iterative approach drawing on multiple data sources over an eight-year period. An inductive ethnographic analysis of stakeholder and partnership meetings was combined with documentary analysis and thematic analysis of interviews with experts by experience and service providers. Findings The voice of lived experience provided by the IF group contributed to the GK partnership through various channels. Evidence of this contribution and its impact was found at programme, city-wide and national levels of the service ecosystem. Furthermore, IF members recognised the value of the group in contributing to systems change and service improvement, but also for themselves. Practical implications This case study serves to illustrate the impact of the lived experience voice on services and systems change, specifically the provision of that voice from a formalised advisory group. The successes and challenges of the group and the experiences of its members are reported with a view to sharing learning that may influence future co-production initiatives with experts by experience and service provision for those experiencing multiple disadvantage. Originality/value The insights provided by the longitudinal observation of the group as it was formed and evolved, coupled with insights provided by the experts by experience, have important implications for facilitating and supporting sustainable lived experience input.

Purpose The purpose of this paper is to present insights into the way in which system change can be activated around the provision of services and support for people experiencing multiple disadvantages in an urban setting. Design/methodology/approach This paper is informed by a thematic analysis of reflections, reports, learning logs, interviews and experiences of those “activating” system change in the Golden Key partnership in Bristol between 2014 and 2021. Findings Four themes are identified, including “creating the conditions for change”, “framing your involvement”, “investing in relationships” and “reflective practice and learning”. For each of these, an illustrative vignette is provided. Practical implications Practical recommendations and reflective questions are provided with suggestions of further considerations for applying this approach in different contexts. Originality/value This paper describes an original approach of activating and supporting people to do system change to improve the lives of people facing multiple disadvantages.

Progressive multiple sclerosis (MS) is driven by demyelination, neuroaxonal loss, and mitochondrial damage occurring behind a closed blood-brain barrier (BBB).1,2 Patients with progressive MS typically fail to respond to available immunomodulatory drugs that reduce relapses in early disease.2 This indicates a dire need to identify non-canonical therapeutic avenues to limit neurodegeneration and promote protection and repair.3 Here, we have employed high-resolution multiomic profiling to characterise the biochemical and metabolic adaptations underpinning MS pathology, as these have been incompletely described but critically, may be amenable to BBB-permeable drug targeting. Using synchrotron radiation (SR)- and focal plane array (FPA)-based Fourier transform infrared microspectroscopy (μFTIR), we spatially mapped the biochemical features present in human progressive MS and control post-mortem brain and rare spinal cord tissue. By employing single-nuclear RNA sequencing (snRNA-seq), 10x Genomics Visium spatial transcriptomics and spatial proteomics to resolve their cellular context, we found that these biochemical features provide a uniquely and highly disease-specific barcode for distinct pathological niches within the tissue. Characterisation of the metabolic processes underpinning these niches revealed an associated re-organisation of the astrocytic landscape in the grey and white matter, with implications for the treatment of progressive MS.

BackgroundMild internal jugular vein (IJV) compression, aimed at increasing intracranial fluid volume to prevent motion of the brain relative to the skull, has reduced brain injury markers in athletes suffering repeated traumatic brain injuries. However, an increase in intracranial volume with IJV compression has not been well demonstrated. This study used transorbital ultrasound to identify changes in optic nerve sheath diameter (ONSD) as a direct marker of accompanying changes in intracranial volume.MethodsNineteen young, healthy adult volunteers (13 males and 6 females) underwent IJV compression of 20 cm H2O low in the neck, while in upright posture. IJV cross-sectional area at the level of the cricoid cartilage, and the change in right ONSD 3 mm behind the papillary segment of the optic nerve, were measured by ultrasound. Statistical analysis was performed using a paired t-test with Bonferroni correction.ResultsMean (SD) cross-sectional area for the right IJV before and after IJV compression was 0.10 (0.05) cm2 and 0.57 (0.37) cm2, respectively (p=0.001). ONSD before and after IJV compression was 4.6 (0.5) mm and 4.9 (0.5) mm, respectively (p=0.001).ConclusionsThese data verify increased cerebral volume following IJV compression, supporting the potential for reduced brain ‘slosh’ as a mechanism connecting IJV compression to possibly reducing traumatic brain injury following head trauma.

We report the case of a 21-year-old female presenting with severe hypernatremia and a gastric outlet obstruction due to chronic purging behavior with salt water flushes. She presented obtunded following emesis and a witnessed seizure. She was found to have a corrected sodium level of 177 mmol/L. Following initial intubation and resuscitation, her CT imaging showed massive gastric dilation with high-density material in the gastric lumen. After orogastric flushing was unsuccessful and the patient's abdominal distention worsened, she was managed surgically and found to have a salt bezoar leading to bowel ischemia and perforation. This case details the complications and management of acute hypernatremia and gastric outlet obstruction in an otherwise healthy, young female. In a society where eating disorders are pervasive, Emergency Medicine physicians should be familiar with dangerous dietary behaviors as well as the management of their rare, but potentially life-threatening, complications.

Export of proteins through type three secretion systems (T3SS) is critical for motility and virulence of many major bacterial pathogens. Proteins are transported through an export gate complex consisting of three proteins (FliPQR in flagellar systems, SctRST in virulence systems) that were initially annotated as membrane proteins, but which we have recently shown assemble into an extra-membranous helical assembly. A fourth putative membrane protein (FlhB/SctU) is essential to the export process, and also functions to “switch” secretion substrate specificity once the growing hook/needle structures reach their determined length. Here we present the structure of an export gate containing the switch protein from a Vibrio polar flagellar system at 3.2 Å resolution by cryo-electron microscopy. The structure reveals that the FlhB/SctU further extends the helical export gate assembly with its four putative transmembrane helices adopting an out-of-membrane location, wrapped around the other export gate components at the base of the structure. The unusual topology of the switch protein helices creates a loop that wraps around the bottom of the closed export gate complex. Structure-informed mutagenesis suggests that this loop is critical in gating secretion and we propose that a series of conformational changes in the type 3 secretion system trigger opening of the export gate through the interactions between FlhB/SctU and FliPQR/SctRST.

Meckel's diverticulum classically follows the rule of two's; presenting before the age of two years, found 2 ft. from the ileocecal valve, approximately 2 in. in length, and present in roughly 2% of the population. To our knowledge, there are few cases detailing emergent medicine management of hemorrhagic shock in patients with acute blood loss from a Meckel's diverticulum. We report the case of a 13-year-old male presenting in hemorrhagic shock secondary to an undifferentiated gastrointestinal bleed who was effectively resuscitated in a children's emergency department. Meckel's scan revealed abnormal tracer uptake consistent with Meckel's diverticulum and the patient underwent surgical resection of the diverticulum. This case report details the importance of prompt recognition and appropriate volume resuscitation in a pediatric patient suffering from hemorrhagic shock. Emergency medicine physicians should maintain an index of suspicion for Meckel's diverticulum in any pediatric patient presenting with undifferentiated gastrointestinal hemorrhage.

BACKGROUND Jojoba butter is cyanogenic and has gained attention among herbal supplement consumers due to claims that it may aid in weight loss. Jojoba butter is extracted from the seeds of jojoba shrubs found in the Sonoran Desert. The seeds have long been recognized as inedible, however clinical symptoms following ingestion are not well documented. CASE REPORT This report describes a patient who developed restlessness and gastrointestinal complaints following ingestion of homemade jojoba seed butter. The patient's presentation following ingestion is discussed, as well as effective workup and treatment. In our case, the patient was monitored and received fluid resuscitation, lorazepam, and diphenhydramine for symptomatic therapy. CONCLUSION This case describes the gastrointestinal sequela and effective management following ingestion of jojoba butter.

The ability of the cerebral vasculature to regulate vascular diameter, hence resistance and cerebral blood flow (CBF), in response to metabolic demands (neurovascular coupling), and perfusion pressure changes (autoregulation) may be assessed by measuring the CBF response to carbon dioxide (CO(2)). In healthy individuals, the CBF response to a ramp CO(2) stimulus from hypocapnia to hypercapnia is assumed sigmoidal or linear. However, other response patterns commonly occur, especially in individuals with cerebrovascular disease, and these remain unexplained. CBF responses to CO(2) in a vascular region are determined by the combined effects of the innate vascular responses to CO(2) and the local perfusion pressure; the latter ensuing from pressure‐flow interactions within the cerebral vascular network. We modeled this situation as two vascular beds perfused in parallel from a fixed resistance source. Our premise is that all vascular beds have a sigmoidal reduction of resistance in response to a progressive rise in CO(2). Surrogate CBF data to test the model was provided by magnetic resonance imaging of blood oxygen level‐dependent (BOLD) signals. The model successfully generated all the various BOLD‐CO(2) response patterns, providing a physiological explanation of CBF distribution as relative differences in the network of vascular bed resistance responses to CO(2). Hum Brain Mapp 38:5590–5602, 2017. © 2017 Wiley Periodicals, Inc.

Currently no biological or radiological marker is available to identify patients at risk of delayed ischemic deficit (DIND) after aneurysmal subarachnoid hemorrhage (aSAH). We hypothesized whether MR-based quantitative assessment of cerebrovascular reserve (CVR) would detect early radiological markers of vasospasm and DIND. This manuscript describes our initial experience with this population. Five patients with aSAH underwent blood-oxygen level dependent-MRI (BOLD-MRI) with CO2 challenge for assessment of whole brain CVR. Patients were examined as soon as possible after aneurysm treatment. We obtained good quality anatomical and functional images without complications. Initial anatomical cerebrovascular imaging showed no vasospasm in all patients. Two patients had abnormal CVR-MRI tests and both developed DIND. Of the 3 others with normal CVR-MRI, one developed posterior circulation DIND. One patient with a normal CVR-MRI developed angiographic vasospasm but no DIND. Changes in CVR maps as early as 36 h after hemorrhage had good spatial correlation with delayed ischemia during short-term follow-up. Our series shows that MRI with CO2 challenge is feasible in this difficult population. Further developments might allow BOLD-MRI with CO2 challenge to identify patients at risk and provide anatomical correlation with future DIND, opening a new venue for prophylactic treatments. Further study is warranted in a larger patient cohort.

Anti-N-methyl-d-aspartate antibody receptor (NMDAR) encephalitis is a newly recognized disease increasing in diagnostic frequency. A 27-year-old female presented with symptoms of oral dyskinesia, tachycardia, and altered mental status following a three-month history of depression, lethargy, catatonia, and auditory hallucinations. We utilized our facilities neurology and psychiatry consult services, performed a lumbar puncture (LP), and requested NMDAR antibody titers. Following admission the Anti-NMDAR antibody titer was elevated warranting treatment with intravenous immunoglobulin (IVIG), corticosteroids, and later rituximab. Organic causes of psychosis are often overlooked in the emergency department, particularly in patients with a history of psychiatric illness. An understanding and awareness of NMDAR encephalitis allows for timely diagnosis, prompting quicker treatment. Emergency physicians should maintain an index of clinical suspicion for NMDAR encephalitis when encountering patients with progressive symptoms of catatonia and psychosis of unclear etiology.

Objective: To describe the cost savings achieved in a health maintenance organization (HMO)-sponsored primary care-based case management and disease management programs. Methods: The HMO-sponsored programs recruited patients in the primary care setting and relied on clinical guidelines and HMO-employed patient education nurses and case management nurses. Total per member per month (PMPM) charges for medical services and changes in selected clinical outcomes before and after entry into HMO-sponsored case management and disease management programs for actively enrolled participants were compared during the fiscal year January 1, 1998 to November 31, 2000. Interventions: The disease management programs addressed asthma, diabetes mellitus and congestive heart failure (CHF). These programs were based on a network of primary care-based nurse educators and case managers promoting clinical guidelines, appropriate use of the insurance benefit, community-based resources, and communication among all healthcare providers. Setting and participants: This initiative was based in 55 primary care sites serving 295 000 insureds across northeastern and central Pennsylvania, USA. Results: 396 patients with asthma had mean baseline PMPM charges of $US298, which decreased to $US276 PMPM after entry. In those with diabetes mellitus, 3556 patients had a mean baseline PMPM charge of $US367 that decreased to $US346. The mean baseline PMPM charge decreased from $US1877 to $US1541 for 1795 patients with CHF. For 3346 patients undergoing case management, the mean baseline PMPM charge was $US1991 and it decreased to $US1545. Total mean reductions in claims over one year of follow-up from the day of entry for patients with asthma, diabetes mellitus, CHF and for case management programs were $US105 544, $US896 112, $US7 237 440 and $US17 907 992, respectively. Additional data regarding asthma-only claims and pre-post days of work loss in the previous six months, diabetes mellitus-only claims and pre-post mean glycosylated hemoglobin A1c values, inpatient and outpatient CHF total claims, ACE inhibitor use in CHF, and inpatient and outpatient total claims in case management are also provided. Conclusion: While these claims data may be limited by a lack of statistical significance and by regression to the mean, they suggest that case management and disease management programs in asthma, diabetes and congestive heart failure can be associated with significant financial savings compared with baseline levels of utilization. Clinical outcomes data also suggest this approach may be of benefit.

Delayed cerebral ischemia (DCI) continues to be a major cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH) because it can only be diagnosed after the onset of clinical symptoms, contributing to poor clinical outcomes and huge use of clinical resources. We hypothesized that early disturbances in cerebrovascular reactivity, noninvasively measured with functional MRI + CO₂, can be a sensitive marker of brain tissue at risk for DCI.Functional MRI exam as soon as possible after the initial bleed and after surgical treatment of the aneurysm was performed in five patients. The functional MRI exam consisted of spatial cerebrovascular reactivity measurements by the blood oxygenation level-dependent (BOLD) response to a standardized carbon dioxide challenge.Of the three patients who later developed DCI, two had abnormal functional MRI study results. The two patients without DCI had normal MRI results. Brain areas with impaired cerebrovascular reactivity on the functional MRI examination demonstrated a spatial correspondence between impaired cerebrovascular reactivity and the onset of DCI.In this feasibility study, functional MRI measurements of cerebrovascular reactivity showed a spatial correspondence between impaired cerebrovascular reactivity and the onset of DCI in patients with aSAH.

Subarachnoid hemorrhage (SAH) alters cerebrovascular reactivity (CVR) to carbon dioxide (CO2), which may be related to an increased risk of delayed ischemic neurological deficits (DINDs). We report the results of bedside CVR testing in the acute phase of SAH in good clinical grade patients without established vasospasm or signs of DIND.Eighteen patients with SAH and 26 healthy subjects underwent CVR testing using transcranial Doppler with standardized changes in CO₂. None of the patients had clinical or radiological evidence of vasospasm or DIND at time of testing. A CVR index was calculated as the change in the middle cerebral artery blood flow velocity (MCAv) divided by the change in the end-tidal CO₂partial pressure (PCO₂), ∆ MCAv/Δ PCO₂, and values were compared with controls.SAH patients had lower CVR when compared with normal controls (p = 0.0001 and p = 0.0094, respectively). Impaired CVR was not correlated with future vasospasm (p = 0.2).Patients with SAH had significantly lower CVR indexes compared with healthy controls. Although impaired CVR was present in 50 % of the patients early after SAH, no correlation with later occurrence of DINDs was found.

Intoxication with the organophosphorus compound paraoxon (POX), an inhibitor of serine hydrolases, is frequent. Although oximes are the only enzyme reactivators presently available, clinical experience with their use was rather disappointing. Recent work has shown that under certain conditions l-lactate is also able to reduce in vitro the POX inhibition of butyrylcholine- and acetylcholineesterase (BChE and AChE). To assess the practical relevance, if any, of these findings, the protective effects of pralidoxime (PRX) and those of lactate had to be compared in the same in vitro model. Effects of PRX on the inhibition of AChE by POX were assessed in vitro in plasma of 12 (six male and six female) healthy human volunteers. The determinations were repeated using different oxime and different POX concentrations. The AChE activity determinations were performed using the following sampler: sample BL-baseline (or untreated plasma); sample a-after addition of POX to plasma (pl + POX); sample b-after POX and plasma were incubated and then oxime was added (pl + POX/PRX); sample c-after addition of oxime to plasma (pl + PRX); sample d-after oxime and plasma were incubated and then POX was added (pl + PRX/POX); sample e-after oxime and POX were incubated and then added to plasma (PRX + POX/pl). Results were corrected for spurious enzyme 'pseudo-activity' due to interaction between PRX and substrate (acetylthiocholine) in the absence of enzyme. In the micro- and millimolar ranges, PRX is able to protect in vitro AChE from inhibition by POX when added to human plasma prior to POX or when incubated with POX prior to addition to plasma. Adding PRX to plasma after POX has no protective effect. The PRX results were compared statistically with historical lactate data (obtained under identical conditions) using the Wilcoxon matched pairs test, with significance assumed for p = 0.01. No difference between PRX and lactate's protective effect on the AChE inhibition by POX was found in the in vitro model used. We therefore conclude that in vivo testing of lactate as a POX protective agent is warranted.

The purpose of the present study was to establish in the mini pig model the effects of paraoxon (POX) on PLA 2 activity. Six anesthetized and mechanically ventilated mini pigs were infused over 50 min with 0.3, 1, 3, 9, 27 and 81 mg POX kg −1 BW −1 dissolved in ethanol, respectively. The control animal received no POX but the ethanol amount corresponding to the highest POX dose. PLA 2 activity measurements were carried out immediately after POX application. Data were analysed with the Mann–Whitney–Wilcoxon rank order test. Statistical significance was assumed for P ≤0.05. Exposure to POX inhibited PLA 2 activity to 50.5±8.9% of baseline activity. The changes seen were not dose-dependent. The dose dependency previously demonstrated in vitro was not reproducible in vivo. This is most probably due to the massive endogenous catecholamine release leading to PLA 2 activation. An additional masking effect is due to the (co)administration of drugs needed for anesthesia and cardiovascular support, especially Mg 2+ . These substances also influence the PLA 2 activity.

Following renewed interest in a class of herbicides containing a 1,1-bisphosphonate moiety, studies to identify the molecular target for these compounds were initiated. N -(2-(3-methylpyridyl)) aminomethylene diphosphonic acid (compound I), a representative example of this group, was found not to inhibit soluble plant pyrophosphatases or H + -translocating pyrophosphatases in the vacuolar membrane. Fatty acid biosynthesis from acetate or from pyruvate was also not suppressed by this herbicide. Germination of plant seeds was not inhibited by the bisphosphonate, but root growth in the dark was strongly inhibited without a significant effect on respiration. The bisphosphonate had little effect on nucleic acid biosynthesis. However, the biosynthesis of carotenoids from isopentenyl pyrophosphate in daffodil ( Narcissus sp. ) chromoplasts was found to be strongly inhibited by compound I at 2.5 μM. Further study showed that isopentenyl pyrophosphate:dimethylallylpyrophosphate isomerase was not blocked by the compound but that farnesyl pyrophosphate synthase was very strongly inhibited by compound I with an IC 50 of 23 nM. It is proposed that bisphosphonates such as compound I are herbicidal as a result of the inhibition of farnesyl pyrophosphate synthase in the prenyl biosynthetic pathway and that this enzyme represents a new target site for the development of herbicides.

We have identified a novel human cyclophilin (hCyP-60) which interacts with the proteinase inhibitor eglin c using the yeast two-hybrid system. A cDNA isolated from a Raji B lymphocyte library reveals a domain showing sequence similarity to known cyclophilins flanked by unique N- and C-terminal residues. In addition, hCyP-60 contains a tyrosine residue (Tyr389) instead of a tryptophan residue found in most eukaryotic cyclophilins at a position important for cyclosporin binding. Northern and Western analysis reveal widespread expression with considerable tissue-specific variation. Specifically, the highest levels of mRNA are detected in the thymus, pancreas, testis, and K-562 cell line, while the most protein is detected in the kidney. Immunohistochemistry indicates a nuclear-specific localization both in transfected cells and tissue sections. hCyP-60's specific subcellular localization and conserved amino acid sequence suggest that it may play a specific role in the nucleus.

Valid routine testing of pulse oximeters and their sensors is problematic. A suitable testing device must not only generate the pulsatile signal the pulse oximeter requires for its operation, but must possess light absorption characteristics similar to those of living tissue. A new device called Pulse Oximeter Tester (POT) has recently become available which, it is claimed, addresses these problems.To evaluate the POT as a suitable stimulus for pulse oximeters.We tested all the pulse oximeters and their sensors with a set of POTs simulating blood oxygen saturation of 80%, 90% and 100%. The tests were performed at simulated heart rates of 30, 75 and 110 bpm.The SpO2 readings (mean +/- SD) obtained with the 80%, 90% and 100% POTs were 80.7 +/- 1.3%, 90.3 +/- 0.9% and 100 +/- 0.0% respectively. There were no significant differences in readings obtained at the different simulated heart rates. Two pulse oximeters gave readings that deviated more than 2 SD from the mean. Their sensors were subsequently found to be defective.POTs provide suitable stimuli for testing pulse oximeters. In our study sample they were found to be highly specific, but of unknown sensitivity.

The purpose of this report is to develop a rational approach to the design of anaesthesia record forms. The history of anaesthesia record forms was reviewed. A logical approach to the design of an anaesthesia record was developed. The theoretical ideal anaesthetic record was contemplated and criteria were developed for the selection of items to be included in or excluded from the record. Principles were outlined which lead to logical organization of information on the form, improved ergonomics of data entry, and ready access to entered information. A desktop publishing system was used to execute quickly numerous form artwork revision cycles and iteratively converge on a complete design. This approach has resulted in the development and production of a new anaesthesia record for our institution. The record was well accepted by our colleagues. The rationale that has been developed is presented in the hope that it will be useful to others in the process of designing anaesthesia records for their institutions.

The agrin family of extracellular matrix proteins may be important in the formation of the neuromuscular junction. Using in situ hybridization with a probe recognizing all agrin isoforms, we demonstrate that it is widely expressed during mammalian embryogenesis. In the developing rat, particularly high levels of expression are found in the dorsal root and cranial ganglia, gut, whisker rudiments, penis, snout, teeth, retina, hippocampus, cerebral cortex and the lining of brain ventricles. Functional analysis of the recombinant rat protein shows that it is a potent inhibitor of the proteases trypsin, chymotrypsin and plasmin but not thrombin or the plasminogen activators. We conclude that agrin and its isoforms may play multiple roles in mammalian development including the regulation of proteolysis in the extracellular matrix.

Focusing on business units (SBUs) in diversified firms, this study investigated the relationships among control systems, resource sharing, and competitive strategies and their interactive effects o...

The effect of budget-based incentive compensation schemes is a fundamental issue in developing and implementing organizational control systems. This study investigates the effect of alternative compensation schemes on performance and satisfaction. A theoretical model outlining the primary relationships is formulated and related hypotheses specified. The hypotheses reflect an integration of agency theory and organization behavior research. Across-group and within-group effects are investigated using both single-period and multiperiod analyses. A laboratory study involving 40 subjects is undertaken and the findings provide insights into the individual and group effects of alternative compensation schemes and the dynamics of changing Compensation schemes on productivity and satisfaction. Specifically, a relationship is found between compensation schemes and performance. The effect on performance is independent of the compensation scheme's perceived fairness. Satisfaction is a function of the congruence between the preferred scheme and the implemented scheme.

Managing human factors in nondestructive evaluation is critical for maintaining inspection reliability. Reliability of structural health monitoring systems is particularly sensitive to sensor degradation over time. To investigate the impact of these issues, probabilistic models for risk assessment and cost‐benefit analysis tools have been developed. Quantitative studies are presented evaluating the effects of variations in probability of detection associated with human factors, plus in‐situ sensor degradation effects on life cycle measures such as cost and probability of failure.

This paper describes the on-going development of a comprehensive integrated guidance and control architecture featuring an on-line aerodynamic identification scheme that produces a global estimate of a damaged vehicle's aerodynamic characteristics. This estimate is used to derive updated constraints reflecting the vehicle's degraded maneuverability that are incorporated into computationally efficient algorithms for on-line trajectory reshaping/retargeting. This paper presents recent progress on a Multiple-Model Adaptive Estimation approach to the global aerodynamic estimation process. The scheme utilizes diagnostic information assumed to be provided by a vehicle health monitor to generate a bank of aerodynamic models in which each model is created by an aerodynamic prediction code for a vehicle configuration reflecting a particular type of damage. The individual models are blended through weights that are adapted on-line using measured data.

This paper describes the development of a comprehensive on-line trajectory generation system that features a novel trajectory design methodology integrated with an innovative on-line aerodynamic identification architecture. The trajectory design methodology employs computationally efficient algorithms yielding feasible trajectories that accommodate degraded vehicle performance resulting from unanticipated vehicle damage and/or malfunction. The aerodynamic identification scheme uses on-line measurements to produce a global estimate of the vehicle's aerodynamic characteristics augmented with local corrections. The end result is a global aerodynamic database for the degraded vehicle from which global aerodynamic constraint estimates are derived and utilized in the trajectory reshaping/retargeting process as well as in the reconfigurable control system.

We present a direct fault tolerant control (DFTC) technique, where by "direct" we mean that no explicit fault identification is used. A technique is presented for the attitude controller (autopilot) for a reusable launch vehicle (RLV), although in principle it can be applied to many other applications. Any partial or complete failure of control actuators and effectors will be inferred from saturation of one or more commanded control signals generated by the controller. The saturation causes a reduction in the effective gain, or bandwidth of the feedback loop, which can be modeled as an increase in singular perturbation in the loop. In order to maintain stability, the bandwidth of the nominal (reduced-order) system is reduced proportionally according to singular perturbation theory. The presented DFTC technique automatically handles momentary saturations and integrator windup caused by excessive disturbances, guidance command or dispersions under normal vehicle conditions.

The implementation of multiple Integrated Guidance and Control (IG&C) algorithms per flight phase within a vehicle simulation poses a daunting task to coordinate algorithm interactions with the other G&C components and with vehicle subsystems. Currently being developed by Universal Space Lines LLC (USL) under contract from NASA, the Integrated Development and Operations System (IDOS) contains a high fidelity Simulink vehicle simulation, which provides a means to test cutting edge G&C technologies. Combining the modularity of this vehicle simulation and Simulink s built-in primitive blocks provide a quick way to implement algorithms. To add discrete-event functionality to the unfinished IDOS simulation, Vehicle Event Manager (VEM) and Integrated Vehicle Health Monitoring (IVHM) subsystems were created to provide discrete-event and pseudo-health monitoring processing capabilities. Matlab's Stateflow is used to create the IVHM and Event Manager subsystems and to implement a supervisory logic controller referred to as the Auto-commander as part of the IG&C to coordinate the control system adaptation and reconfiguration and to select the control and guidance algorithms for a given flight phase. Manual creation of the Stateflow charts for all of these subsystems is a tedious and time-consuming process. The Stateflow Auto-builder was developed as a Matlab based software tool for the automatic generation of a Stateflow chart from information contained in a database. This paper describes the IG&C, VEM and IVHM implementations in IDOS. In addition, this paper describes the Stateflow Auto-builder.