1,191 research outputs found

    Operations analysis of Fleet battle experiments using the Battlespace Information War methodology: preliminary report

    Get PDF
    This report outlines an approach for quantitative operations analysis of aspects of Fleet Battle Experiments (FBEs) using the methodology underlying the Battlespace Information War (BAT/IW) analytical tool. The general approach of this analysis methodology is to focus on a specific experimental initiative from one or more FBEs, such as Time Critical Targeting (TCT). BAT/IW models are then tailored to the experimental situation using actual data obtained from one or more experiments and the experiment systems architecture. After the models and actual data are reconciled, further analysis tasks are undertaken, such as predictions of the effects of attack intensity, and/or of C4ISR response time reduction. BAT/IW modeling helps analyze and understand the system-level impact of sensor data quality, including timeliness, as one contributor to total operation/campaign success. BAT/IW modeling also accounts for the latency involved in processing information, including communications delays, decision time, waiting, etc. An example is developed to show how operational data obtained during FBE Foxtrot can be quantitatively analyzed to indicate important sensitivities.--Report documentation page.Approved for public release; distribution is unlimited

    B833: A Residential Waste Stream Analysis: Orono, Maine, 1990

    Get PDF
    George Criner and Chet Rock of the University of Maine, and students from their Waste Management class analyzed household wastes from 33 residences in Orono. The purpose of the analysis was to obtain an estimate of total weekly residential waste weight and its composition by category (paper versus glass, etc.).https://digitalcommons.library.umaine.edu/aes_bulletin/1022/thumbnail.jp

    Magnitude effects for experienced rewards at short delays in the escalating interest task

    Get PDF
    A first-person shooter video game was adapted for the study of choice between smaller sooner and larger later rewards. Participants chose when to fire a weapon that increased in damage potential over a short interval. When the delay to maximum damage was shorter (5 – 8 s), people showed greater sensitivity to the consequences of their choices than when the delay was longer (17 – 20 s). Participants also evidenced a magnitude effect by waiting proportionally longer when the damage magnitudes were doubled for all rewards. The experiment replicated the standard magnitude effect with this new video game preparation over time scales similar to those typically used in nonhuman animal studies and without complications due to satiation or cost

    Data Curation in Climate and Weather: Transforming Our Ability to Improve Predictions through Global Knowledge Sharing

    Get PDF
    Climate and Weather are of increasing interest to the scientific community and the general public. Data curation and stewardship are essential building blocks in the science community’s quest to better understand how natural climate and weather systems behave and how activities of human civilization are altering the natural system. Rudimentary observations of the atmosphere and ocean have been collected for over one hundred years and proxity measurements of the climate can trace our planet’s climatic history for millions of years. These observations coupled with the rapid advances in technology, such as powerful computers, rapid access to massive amounts of data, and satellite observations, have allowed innovative techniques to be used to understand and predict the planet’s climate and weather

    Systemic lobar shunting induces advanced pulmonary vasculopathy

    Get PDF
    AbstractObjectives: We characterized the morphology and vasomotor responses of a localized, high-flow model of pulmonary hypertension. Methods: An end-to-side anastomosis was created between the left lower lobe pulmonary artery and the aorta in 23 piglets. Control animals had a thoracotomy alone or did not have an operation. Eight weeks later, hemodynamic measurements were made. Then shunted and/or nonshunted lobes were removed for determination of vascular resistance and compliance by occlusion techniques under conditions of normoxia, hypoxia (FIO2 = 0.03), and inspired nitric oxide administration. Quantitative histologic studies of vessel morphology were performed. Results: Eighty-three percent of animals having a shunt survived to final study. Aortic pressure, main pulmonary artery and wedge pressures, cardiac output, blood gases, and weight gain were not different between control pigs and those receiving a shunt. Six of 9 shunted lobes demonstrated systemic levels of pulmonary hypertension in vivo. Arterial resistance was higher (24.3 ± 12.0 vs 1.3 ± 0.2 mm Hg · mL–1 · s–1, P =.04) and arterial compliance was lower (0.05 ± 0.01 vs 0.16 ± 0.03 mL/mm Hg, P =.02) in shunted compared with nonshunted lobes. Hypoxic vasoconstriction was blunted in shunted lobes compared with nonshunted lobes (31% ± 13% vs 452% ± 107% change in arterial resistance, during hypoxia, P <.001). Vasodilation to inspired nitric oxide was evident only in shunted lobes (34% ± 6% vs 1.8% ± 8.2% change in arterial resistance during administration of inspired nitric oxide, P =.008). Neointimal and medial proliferation was found in shunted lobes with approximately a 10-fold increase in wall/luminal area ratio. Conclusions: An aorta–lobar pulmonary artery shunt produces striking vasculopathy. The development of severe pulmonary hypertension within a short time frame, low mortality, and localized nature of the vasculopathy make this model highly attractive for investigation of mechanisms that underlie pulmonary hypertension. (J Thorac Cardiovasc Surg 2000; 120:88-98

    Free and total insulin-like growth factor I (IGF-I), IGF-binding protein-1 (IGFBP-1), and IGFBP-3 and their relationships to the presence of diabetic retinopathy and glomerular hyperfiltration in insulin-dependent diabetes mellitus

    Get PDF
    The existing literature on serum insulin-like growth factor I (IGF-I) levels in insulin-dependent diabetes mellitus (IDDM) is conflicting. Free IGF-I may have greater physiological and clinical relevance than total IGF-I. Recently, a validated method has been developed to measure free IGF-I levels in the circulation. Serum free and total IGF-I, IGF-binding protein-1 (IGFBP-1), and IGFBP-3 levels were measured in 56 insulin-treated IDDM patients and 52 healthy sex- and age-matched controls. Diabetic retinopathy was established by direct fundoscopy. In 54 IDDM patients, the glomerular filtration rate (GFR) and effective renal plasma flow were calculated from the clearance rate of [125I]iothalamate and [131I]iodohippurate sodium. Fasting free IGF-I, total IGF-I, and IGFBP-3 levels were significantly lower in IDDM patients than in age- and sex-matched healthy controls (free IGF-I, P < 0.005; total IGF-I, P < 0.001; IGFBP-3, P = 0.001), whereas IGFBP-1 levels were higher (P < 0.001). In IDDM subjects, decreases in free IGF-I, total IGF-I, and IGFBP-3 levels with age were observed (free IGF-I, r = -0.27 and P = 0.05; total IGF-I, r = -0.52 and P < 0.001; IGFBP-3, r = -0.37 and P = 0.005). Free IGF-I was inversely related to fasting glucose in IDDM subjects (r = -0.35; P = 0.01), whereas the relationship between total IGF-I and fasting glucose did not reach significance (r = -0.27; P = 0.06). Age-adjusted free IGF-I levels were significantly higher (P < 0.05) in IDDM subjects with retinopathy than in subjects without retinopathy after adjustment for age. Total IGF-I and IGFBP-3 levels were positively related to GFR (total IGF-I, r = 0.35 and P < 0.05; IGFBP-3, r = 0.28 and P < 0.05). Both of these differences lost significance after adjustment for age. Free IGF-I, total IGF-I, and IGFBP-3 levels were lower and IGFBP-1 levels were higher in insulin-treated IDDM subjects compared to those in age- and sex-matched controls. Free IGF-I, total IGF-I, and IGFBP-3 levels decreased significantly with age in IDDM subjects. Age-adjusted free IGF-I levels in subjects with diabetic retinopathy were higher than those in subjects without diabetic retinopathy. Total IGF-I and IGFBP-3 levels were positively related to GFR in IDDM subjects, but these relations were lost after adjustment for age. Measurement of serum free IGF-I levels in IDDM subjects did not have clear advantages compared to that of total IGF-I, IGFBP-1, and IGFBP-3 levels. Serum IGF-I and IGFBPs reflect their tissue concentrations to a various degree. Consequently, extrapolations concerning the pathogenetic role of the IGF/IGFBP system in the development of diabetic complications at the tissue level remain speculative

    Hepatic angiotensin-converting enzyme 2 expression in metabolic dysfunction-associated steatotic liver disease and in patients with fatal COVID-19

    Get PDF
    BACKGROUND Metabolic dysfunction-associated steatotic liver disease (MASLD), characterised by hepatic lipid accumulation, causes inflammation and oxidative stress accompanied by cell damage and fibrosis. Liver injury (LI) is also frequently reported in patients hospitalised with coronavirus disease 2019 (COVID-19), while preexisting MASLD increases the risk of LI and the development of COVID-19associated cholangiopathy. Mechanisms of injury at the cellular level remain unclear, but it may be significant that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes COVID-19, uses angiotensin-converting expression enzyme 2 (ACE2), a key regulator of the ‘anti-inflammatory’ arm of the renin-angiotensin system, for viral attachment and host cell invasion. AIM To determine if hepatic ACE2 levels are altered during progression of MASLD and in patients who died with severe COVID-19. METHODS ACE2 protein levels and localisation, and histological fibrosis and lipid droplet accumulation as markers of MASLD were determined in formalin-fixed liver tissue sections across the MASLD pathological spectrum (isolated hepatocellular steatosis, metabolic dysfunction-associated steatohepatitis (MASH) +/- fibrosis, end-stage cirrhosis) and in post-mortem tissues from patients who had died with severe COVID-19, using ACE2 immunohistochemistry and haematoxylin and eosin and picrosirius red staining of total collagen and lipid droplet areas, followed by quantification using machine learning-based image pixel classifiers. RESULTS ACE2 staining is primarily intracellular and concentrated in the cytoplasm of centrilobular hepatocytes and apical membranes of bile duct cholangiocytes. Strikingly, ACE2 protein levels are elevated in non-fibrotic MASH compared to healthy controls but not in the progression to MASH with fibrosis and in cirrhosis. ACE2 protein levels and histological fibrosis are not associated, but ACE2 and liver lipid droplet content are significantly correlated across the MASLD spectrum. Hepatic ACE2 levels are also increased in COVID-19 patients, especially those showing evidence of LI, but are not correlated with the presence of SARS-CoV-2 virus in the liver. However, there is a clear association between the hepatic lipid droplet content and the presence of the virus, suggesting a possible functional link. CONCLUSION Hepatic ACE2 levels were elevated in nonfibrotic MASH and COVID-19 patients with LI, while lipid accumulation may promote intra-hepatic SARS-CoV-2 replication, accelerating MASLD progression and COVID-19-mediated liver damage.</p
    • …
    corecore