555 research outputs found

    Fault detection and isolation for multisensor navigation systems

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    Increasing attention is being given to the problem of erroneous measurement data for multisensor navigation systems. A recursive estimator can be used in conjunction with a 'snapshot' batch estimator to provide fault detection and isolation (FDI) for these systems. A recursive estimator uses past system states to form a new state estimate and compares it to the calculated state based on a new set of measurements. A 'snapshot' batch estimator uses a set of measurements collected simultaneously and compares solutions based on subsets of measurements. The 'snapshot' approach requires redundant measurements in order to detect and isolate faults. FDI is also referred to as Receiver Autonomous Integrity Monitoring (RAIM)

    Emergency Department Cardiopulmonary Evaluation of Low-Risk Chest Pain Patients with Self-Reported Stress and Anxiety

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    Background Chest pain is a high-risk emergency department (ED) chief complaint; the majority of clinical resources are directed toward detecting and treating cardiopulmonary emergencies. However, at follow-up, 80%–95% of these patients have only a symptom-based diagnosis; a large number have undiagnosed anxiety disorders. Objective Our aim was to measure the frequency of self-identified stress or anxiety among chest pain patients, and compare their pretest probabilities, care processes, and outcomes. Methods Patients were divided into two groups: explicitly self-reported anxiety and stress or not at 90-day follow-up, then compared on several variables: ultralow (<2.5%) pretest probability, outcome rates for acute coronary syndrome (ACS) and pulmonary embolism (PE), radiation exposure, total costs at 30 days, and 90-day recidivism. Results Eight hundred and forty-five patients were studied. Sixty-seven (8%) explicitly attributed their chest pain to “stress” or “anxiety”; their mean ACS pretest probability was 4% (95% confidence interval 2.9%–5.7%) and 49% (33/67) had ultralow pretest probability (0/33 with ACS or PE). None (0/67) were diagnosed with anxiety. Seven hundred and seventy-eight did not report stress or anxiety and, of these, 52% (403/778) had ultralow ACS pretest probability. Only one patient (0.2%; 1/403) was diagnosed with ACS and one patient (0.4%; 1/268) was diagnosed with PE. Patients with self-reported anxiety had similar radiation exposure, associated costs, and nearly identical (25.4% vs. 25.7%) ED recidivism to patients without reported anxiety. Conclusions Without prompting, 8% of patients self-identified “stress” or “anxiety” as the etiology for their chest pain. Most had low pretest probability, were over-investigated for ACS and PE, and not investigated for anxiety syndromes

    Anxiety Associated With Increased Risk for Emergency Department Recidivism in Patients With Low-Risk Chest Pain

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    Anxiety contributes to the chest pain symptom complex in 30% to 40% of patients with low-risk chest pain seen in the emergency department (ED). The validated Hospital Anxiety Depression Scale-Anxiety subscale (HADS-A) has been used as an anxiety screening tool in this population. The objective was to determine the prevalence of abnormal HADS-A scores in a cohort of low-risk chest pain patients and test the association of HADS-A score with subsequent healthcare utilization and symptom recurrence. In a single-center, prospective, observational cohort study of adult ED subjects with low-risk chest pain, the HADS-A was used to stratify participants into 2 groups: low anxiety (score <8) and high anxiety (score ≥8). At 45-day follow-up, chest pain recurrence was assessed by patient report, whereas ED utilization was assessed through chart review. Of the 167 subjects enrolled, 78 (47%) were stratified to high anxiety. The relative risk for high anxiety being associated with at least one 30-day ED return visit was 2.6 (95% confidence interval 1.4 to 4.7) and this relative risk increased to 9.1 (95% confidence interval 2.18 to 38.6) for 2 or more ED return visits. Occasional chest pain recurrence was reported by more subjects in the high anxiety group, 68% vs 47% (p = 0.029). In conclusion, 47% of low-risk chest pain cohort had abnormal levels of anxiety. These patients were more likely to have occasional recurrence of their chest pain and had an increased risk multiple ED return visits

    Higher Education Instructional Change in a U.S. Context: Investigating the Scholarship of Teaching and Learning (SoTL) Innovations at Niagara University

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    A metà Settembre 2013, due degli autori di questo articolo sono stati a Lecce (Italia) realizzando una presentazionein una conferenza sull’istruzione superiore. In quella sede, è stato possibile condividere con i partecipanti i dieci cambiamenti più potenti e significativi che hanno avuto luogo nel vasto panoramadell’accademia americana. L’elenco si componeva di sviluppi di tipo teorico; così come da diversi livelli di implementazione e pratica presso l’Università di Niagara, nell’angolo Nord Est degli Stati Uniti. Tra le iniziative messe in evidenza è stata prima e soprattutto menzionato il lavoro di Ernest Boyer sulla Scholarshipof Teaching and Learning (SoTL), ovvero la sua visione su strade alternative comunque accademiche, basate sulla didattica, per il successo della formazione universitaria. Il percorso tracciato dal movimento SoTL cambia la cultura universitaria, collocando l’insegnamento come priorità; e la “scholarship” (ricerca didattica) emergente dagli studi sull’innovazione didattica come una disciplina di ricerca che può alinearse ad altre nell’ambito accademico. Le esperienze all’Università Niagara forniscono sia un caso di studio dell’implementazione dei suddetti concetti in una moderna istituzione americana; sia un’opportunità per la comparazione con i vari casi delle istituzioni italiane. Inoltre, il lavoro portato avanti dall’università di Niagara risulta competitivo con riguardo ad alcune delle più riconosciute università americane, potendo essere considerato all’avanguardia dell’emergente movimentoSoTL. Questo articolo fornisce un breve resoconto e definizione del modello di Boyer su SoTL, suggerendo come le istituzioni potrebbero adottare tale paradigma sia come strategia per lo sviluppo professionale accademico, sia come adeguata base per la valutazione del lavoro del docente universitario

    Temporal profiling of the cortical synaptic mitochondrial proteome identifies ageing associated regulators of stability

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    Synapses are particularly susceptible to the effects of advancing age, and mitochondria have long been implicated as organelles contributing to this compartmental vulnerability. Despite this, the mitochondrial molecular cascades promoting age-dependent synaptic demise remain to be elucidated. Here, we sought to examine how the synaptic mitochondrial proteome (including strongly mitochondrial associated proteins) was dynamically and temporally regulated throughout ageing to determine whether alterations in the expression of individual candidates can influence synaptic stability/morphology. Proteomic profiling of wild-type mouse cortical synaptic and non-synaptic mitochondria across the lifespan revealed significant age-dependent heterogeneity between mitochondrial subpopulations, with aged organelles exhibiting unique protein expression profiles. Recapitulation of aged synaptic mitochondrial protein expression at the Drosophila neuromuscular junction has the propensity to perturb the synaptic architecture, demonstrating that temporal regulation of the mitochondrial proteome may directly modulate the stability of the synapse in vivo

    Navy Force Structure Review Strategic Risk Workshop and Technology Review

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    NPS NRP Project PosterThe study's goal is to comparatively evaluate combat effectiveness of the planned Fleet Design with a novel alternative design against potential global adversaries in the 2040 timeframe. Insights and recommendations from the study will be used in the next Force Structure Assessment and the FY 2024 30-Year Shipbuilding Plan.N8 - Integration of Capabilities & ResourcesThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

    Navy Force Structure Review Strategic Risk Workshop and Technology Review

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    NPS NRP Executive SummaryThe study's goal is to comparatively evaluate combat effectiveness of the planned Fleet Design with a novel alternative design against potential global adversaries in the 2040 timeframe. Insights and recommendations from the study will be used in the next Force Structure Assessment and the FY 2024 30-Year Shipbuilding Plan.N8 - Integration of Capabilities & ResourcesThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

    Reflected Shock Tunnel Noise Measurement by Focused Differential Interferometry

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    A series of experiments is conducted where a quantitative non-intrusive optical technique is used to investigate disturbances in the free-stream of T5, the free-piston driven reflected shock tunnel at Caltech. The optical technique, focused laser differential interferometry (FLDI), measures fluctuations in density. In the test matrix, reservoir enthalpy is varied while the reservoir pressure is held fixed. The results show the perturbations in density are not a strong function of the reservoir enthalpy. During one experiment, exceptional levels of noise were detected; this unique result is attributed to non-ideal operation of the shock tunnel. The data indicate that rms density fluctuations of less than 0.75% are achievable with attention to tunnel cleanliness. In addition, the spectral content of density fluctuation does not change throughout the test time

    Chronic Embolic Pulmonary Hypertension Caused by Pulmonary Embolism and Vascular Endothelial Growth Factor Inhibition

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    Our understanding of the pathophysiological basis of chronic thromboembolic pulmonary hypertension (CTEPH) will be accelerated by an animal model that replicates the phenotype of human CTEPH. Sprague-Dawley rats were administered a combination of a single dose each of plastic microspheres and vascular endothelial growth factor receptor antagonist in polystyrene microspheres (PE) + tyrosine kinase inhibitor SU5416 (SU) group. Shams received volume-matched saline; PE and SU groups received only microspheres or SU5416, respectively. PE + SU rats exhibited sustained pulmonary hypertension (62 ± 13 and 53 ± 14 mmHg at 3 and 6 weeks, respectively) with reduction of the ventriculoarterial coupling in vivo coincident with a large decrement in peak rate of oxygen consumption during aerobic exercise, respectively. PE + SU produced right ventricular hypokinesis, dilation, and hypertrophy observed on echocardiography, and 40% reduction in right ventricular contractile function in isolated perfused hearts. High-resolution computed tomographic pulmonary angiography and Ki-67 immunohistochemistry revealed abundant lung neovascularization and cellular proliferation in PE that was distinctly absent in the PE + SU group. We present a novel rodent model to reproduce much of the known phenotype of CTEPH, including the pivotal pathophysiological role of impaired vascular endothelial growth factor-dependent vascular remodeling. This model may reveal a better pathophysiological understanding of how PE transitions to CTEPH in human treatments
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