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Sample records for mimicking worst-case scenarios

  1. Surface disinfection tests with Salmonella and a putative indicator bacterium, mimicking worst-case scenarios in poultry houses.

    PubMed

    Gradel, K O; Sayers, A R; Davies, R H

    2004-10-01

    Surface disinfection studies mimicking worst-case scenarios in badly cleaned poultry houses were made with 3 bacterial isolates (Salmonella enteritidis, Salmonella senftenberg, and Enterococcus faecalis), and 3 1% disinfectant solutions, formaldehyde (F; 24.5% vol/vol), glutaraldehyde/benzalkonium chloride (G; Bio Komplet Plus), and a peroxygen compound (P; Virkon S), with World Health Organization (WHO) standard hard water as a control. Materials (concrete paving stones, steel feed chain links, wooden dowels, and jute egg belts) and organic matter found commonly in poultry houses (feed, fats, egg yolk) were used in the tests. Organic matter inoculated with high numbers of stationary phase cultures was added to materials and dried for 24 h at different temperatures (6, 11, 20, or 30 degrees C), immersed in solutions for set time periods (5, 15, or 30 min), and dried again for 25 h (6, 11, or 30 degrees C). Then, traditional recovery procedures (using 10-fold dilutions until 10(-4), i.e., a most probable number method) were applied. For the 2 Salmonella isolates, the efficacy of the solutions was (in decreasing order): formaldehyde > glutaraldehyde/benzalkonium chloride > peroxygen compound > WHO hard water, except when feed chain links with fats were disinfected using 30 degrees C before and after disinfection, for which the peroxygen compound seemed more effective. Enterococcus faecalis was equally or less susceptible than S. enteritidis and S. senftenberg, indicating its suitability as an indicator bacterium. For the peroxygen compound, S. senftenberg was more susceptible than S. enteritidis in spite of higher minimum inhibitory concentrations to this disinfectant for the former.

  2. Extreme solar particle events: The worst case scenario

    NASA Astrophysics Data System (ADS)

    Usoskin, Ilya; Kovaltsov, Gennady

    2016-04-01

    Sporadic eruptive energetic events on the Sun may occur during periods of high solar activity. Sometimes such events can be strong or even extreme posing serious hazards for the modern technology and communication dependent society. It is important to asses the worst case scenario for an extreme solar particle event and what the probability of its occurrence. The era of direct scientific exploration of the Sun is short - from few decades to a century, and yet several strong harmful events took place during that time. Can we expect even greater events? How often? What shall we prepare for? In order to answer these questions, one has to rely upon indirect methods by analyzing natural proxy archives. Here we present an overview of the history of extreme solar events in the past, from hundreds to millions of year, based on an analysis of cosmogenic isotopes in terrestrial archives (polar ice cores and tree rings) and in lunar rocks.

  3. Reducing Probabilistic Weather Forecasts to the Worst-Case Scenario: Anchoring Effects

    ERIC Educational Resources Information Center

    Joslyn, Susan; Savelli, Sonia; Nadav-Greenberg, Limor

    2011-01-01

    Many weather forecast providers believe that forecast uncertainty in the form of the worst-case scenario would be useful for general public end users. We tested this suggestion in 4 studies using realistic weather-related decision tasks involving high winds and low temperatures. College undergraduates, given the statistical equivalent of the…

  4. Reducing Probabilistic Weather Forecasts to the Worst-Case Scenario: Anchoring Effects

    ERIC Educational Resources Information Center

    Joslyn, Susan; Savelli, Sonia; Nadav-Greenberg, Limor

    2011-01-01

    Many weather forecast providers believe that forecast uncertainty in the form of the worst-case scenario would be useful for general public end users. We tested this suggestion in 4 studies using realistic weather-related decision tasks involving high winds and low temperatures. College undergraduates, given the statistical equivalent of the…

  5. 30 CFR 254.47 - Determining the volume of oil of your worst case discharge scenario.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... discharge scenario as follows: (a) For an oil production platform facility, the size of your worst case... from a break in any pipelines connected to the facility considering shutdown time, the effect of hydrostatic pressure, gravity, frictional wall forces and other factors; and (3) The daily production volume...

  6. Selection of Worst-Case Pesticide Leaching Scenarios for Pesticide Registration

    NASA Astrophysics Data System (ADS)

    Vereecken, H.; Tiktak, A.; Boesten, J.; Vanderborght, J.

    2010-12-01

    The use of pesticides, fertilizers and manure in intensive agriculture may have a negative impact on the quality of ground- and surface water resources. Legislative action has been undertaken in many countries to protect surface and groundwater resources from contamination by surface applied agrochemicals. Of particular concern are pesticides. The registration procedure plays an important role in the regulation of pesticide use in the European Union. In order to register a certain pesticide use, the notifier needs to prove that the use does not entail a risk of groundwater contamination. Therefore, leaching concentrations of the pesticide need to be assessed using model simulations for so called worst-case scenarios. In the current procedure, a worst-case scenario represents a parameterized pesticide fate model for a certain soil and a certain time series of weather conditions that tries to represent all relevant processes such as transient water flow, root water uptake, pesticide transport, sorption, decay and volatilisation as accurate as possible. Since this model has been parameterized for only one soil and weather time series, it is uncertain whether it represents a worst-case condition for a certain pesticide use. We discuss an alternative approach that uses a simpler model that requires less detailed information about the soil and weather conditions but still represents the effect of soil and climate on pesticide leaching using information that is available for the entire European Union. A comparison between the two approaches demonstrates that the higher precision that the detailed model provides for the prediction of pesticide leaching at a certain site is counteracted by its smaller accuracy to represent a worst case condition. The simpler model predicts leaching concentrations less precise at a certain site but has a complete coverage of the area so that it selects a worst-case condition more accurately.

  7. The effects of vehicular exhaust buoyancy during worst case pollution scenarios near roadways

    SciTech Connect

    Held, A.E.; Chang, D.P.Y.; Carroll, J.J.

    1998-12-31

    The California Department of Transportation (CALTRANS) has been using CALINE4, a gaussian finite line-source dispersion model, to estimate air pollutant concentrations near roadways given an estimate of traffic flow rates, vehicular emission factors, roadway geometry, and local meteorology. Modelers have typically used CALINE4 to simulate low wind near parallel thermally stable conditions to estimate a worst case pollution scenario (i.e., highest predicted pollutant concentrations) for a proposed roadway. In October 1995, the University of California, Davis (UCD), in conjunction with the CALTRANS Environmental Program, began a two-year investigation to determine if CALINE4 was adequately predicting CO concentrations during worst case meteorological conditions. Based on physical reasoning and a literature review of several highway dispersion studies conducted in the late 1970`s, it was reasoned that gaussian models may over-predict CO concentrations during worst case scenarios because these models do not adequately parameterize the increased vertical dispersion of pollutants due to vehicular emission buoyancy. To explore the role that exhaust buoyancy plays in roadway pollutant dispersion, a series of experiments were conducted on I-80 (near Sacramento) during winter pre-dawn commute hours. Results of the dispersion studies were inconclusive due to difficulty in capturing sufficiently low wind speed conditions during the sampling effort, however, in a compare-contrast study of field measurements versus CALINE4 predictions it was verified that CALINE4 adequately predicts both the magnitude and qualitative shape of non-worst case pollution scenarios. In addition, based on integrated mass flux from downwind CO concentration and wind profiles it was found that the use of CT-EMFAC, a regional scale emission factor model, overpredicted observed modal emissions by as much as 250 to 480%.

  8. Biomechanical behavior of a cemented ceramic knee replacement under worst case scenarios

    NASA Astrophysics Data System (ADS)

    Kluess, D.; Mittelmeier, W.; Bader, R.

    2009-12-01

    In connection with technological advances in the manufacturing of medical ceramics, a newly developed ceramic femoral component was introduced in total knee arthroplasty (TKA). The motivation to consider ceramics in TKA is based on the allergological and tribological benefits as proven in total hip arthroplasty. Owing to the brittleness and reduced fracture toughness of ceramic materials, the biomechanical performance has to be examined intensely. Apart from standard testing, we calculated the implant performance under different worst case scenarios including malposition, bone defects and stumbling. A finite-element-model was developed to calculate the implant performance in situ. The worst case conditions revealed principal stresses 12.6 times higher during stumbling than during normal gait. Nevertheless, none of the calculated principal stress amounts were above the critical strength of the ceramic material used. The analysis of malposition showed the necessity of exact alignment of the implant components.

  9. Biomechanical behavior of a cemented ceramic knee replacement under worst case scenarios

    NASA Astrophysics Data System (ADS)

    Kluess, D.; Mittelmeier, W.; Bader, R.

    2010-03-01

    In connection with technological advances in the manufacturing of medical ceramics, a newly developed ceramic femoral component was introduced in total knee arthroplasty (TKA). The motivation to consider ceramics in TKA is based on the allergological and tribological benefits as proven in total hip arthroplasty. Owing to the brittleness and reduced fracture toughness of ceramic materials, the biomechanical performance has to be examined intensely. Apart from standard testing, we calculated the implant performance under different worst case scenarios including malposition, bone defects and stumbling. A finite-element-model was developed to calculate the implant performance in situ. The worst case conditions revealed principal stresses 12.6 times higher during stumbling than during normal gait. Nevertheless, none of the calculated principal stress amounts were above the critical strength of the ceramic material used. The analysis of malposition showed the necessity of exact alignment of the implant components.

  10. Advantages and limitations of the 'worst case scenario' approach in IMPT treatment planning.

    PubMed

    Casiraghi, M; Albertini, F; Lomax, A J

    2013-03-07

    The 'worst case scenario' (also known as the minimax approach in optimization terms) is a common approach to model the effect of delivery uncertainties in proton treatment planning. Using the 'dose-error-bar distribution' previously reported by our group as an example, we have investigated in more detail one of the underlying assumptions of this method. That is, the dose distributions calculated for a limited number of worst case patient positioning scenarios (i.e. limited number of shifts sampled on a spherical surface) represent the worst dose distributions that can occur during the patient treatment under setup uncertainties. By uniformly sampling patient shifts from anywhere within a spherical error-space, a number of treatment scenarios have been simulated and dose deviations from the nominal dose distribution have been computed. The dose errors from these simulations (comprehensive approach) have then been compared to the dose-error-bar approach previously reported (surface approximation) using both point-by-point and dose- and error-volume-histogram analysis (DVH/EVHs). This comparison has been performed for two different clinical cases treated using intensity modulated proton therapy (IMPT): a skull-base and a spinal-axis tumor. Point-by-point evaluation shows that the surface approximation leads to a correct estimation (95% accuracy) of the potential dose errors for the 96% and 85% of the irradiated voxels, for the two investigated cases respectively. We also found that the voxels for which the surface approximation fails are generally localized close to sharp soft tissue-bone interfaces and air cavities. Moreover, analysis of EVHs and DVHs for the two cases shows that the percentage of voxels of a given volume of interest potentially affected by a certain maximum dose error is correctly estimated using the surface approximation and that this approach also accurately predicts the upper and lower bounds of the DVH curves that can occur under positioning

  11. In vitro model improves the prediction of soil arsenic bioavailability: worst-case scenario.

    PubMed

    Makris, Konstantinos C; Quazi, Shahida; Nagar, Rachana; Sarkar, Dibyendu; Datta, Rupali; Sylvia, Victor L

    2008-08-15

    There is a strong interest in developing an in vitro arsenic (As) model that satisfactorily estimates the variability in in vivo relative oral bioavailability (RBA) measurements. Several in vitro tests have been developed, but none is universally accepted due to their limited success in predicting soil As RBA. A suite of amorphous and crystalline solid As phases were chosen, utilizing a worst-case scenario (WCS) that simulated fasting children's gastric solution chemistry. The objectives of this study were to (i) determine the effects of residence time, pH, and solid-to-solution ratio on As bioaccessibility and speciation in the in vitro gastric test; (ii) provide the fundamental basis for an optimized in vitro model constrained by the WCS; and (iii) validate the optimized in vitro test with the in vivo RBA obtained with BALB/c mice. The gastric pH was the only significant (p < 0.05) factor influencing solid As bioaccessibility. Bioaccessible As retained the oxidation state after its release from the solid into the gastric solution. The optimized in vitro model adequately predicted RBA values for a suite of solid As phases typically encountered in soils, with the exception of aluminum-based solids. This study is an excellent starting point for developing an in vitro test applicable to different As-contaminated soils.

  12. Worst-case scenario approach to the tsunami hazard assessment for the Apulian coasts (southern Italy)

    NASA Astrophysics Data System (ADS)

    Armigliato, Alberto; Pagnoni, Gianluca; Zaniboni, Filippo; Tinti, Stefano

    2014-05-01

    In the framework of the Mediterranean basin, Apulia cannot be counted among the most active areas in terms of earthquake and tsunami activity. Nonetheless, in its northern part, which includes the Gargano peninsula, several earthquakes with magnitudes up to 6.7 occurred historically, some of which were also tsunamigenic. The most famous one is the 30 July 1627 event, which produced extensive inundation in the northern part of Gargano and relevant effects also in some portions of its southern side. Its parent fault is still a matter of debate, since both the inland epicentral location determined by macroseismic studies and the strike-slip dominant focal mechanism inferred from local geology are incompatible with a tsunami excitation capable of producing the effects reported by the coeval sources. Moreover, Apulia is bounded by much more tectonically active and tsunamigenic regions, such as the Dalmatia-Montenegro-Albania coastal belt to the East, the western Hellenic Arc to the South-East and the Calabrian arc to the South-West. Finally, Apulia is located in a strategic position in between eastern and western Europe, involving the installation of crucial international infrastructures, such as the Trans-Adriatic gas pipeline. For all the reasons mentioned above, performing an accurate assessment of the hazard related (at least) to earthquakes and tsunami impact in Apulia represents a need. The OTRIONS project developed a multi-parametric network for this purpose, and in its framework we studied the tsunami hazard along the Apulian coasts by means of a worst-case credible scenario approach. This involved the selection and characterisation of all possible tsunamigenic sources both at local and remote distances: this task was carried out as a shared effort with the Italian national RITMARE project. The recognised sources, mainly retrieved from the published literature and from databases available online, include tectonic faults as well as submarine landslides. The

  13. Possible worst-case tsunami scenarios around the Marmara Sea from combined earthquake and landslide sources

    NASA Astrophysics Data System (ADS)

    Latcharote, Panon; Suppasri, Anawat; Imamura, Fumihiko; Aytore, Betul; Yalciner, Ahmet Cevdet

    2016-12-01

    This study evaluates tsunami hazards in the Marmara Sea from possible worst-case tsunami scenarios that are from submarine earthquakes and landslides. In terms of fault-generated tsunamis, seismic ruptures can propagate along the North Anatolian Fault (NAF), which has produced historical tsunamis in the Marmara Sea. Based on the past studies, which consider fault-generated tsunamis and landslide-generated tsunamis individually, future scenarios are expected to generate tsunamis, and submarine landslides could be triggered by seismic motion. In addition to these past studies, numerical modeling has been applied to tsunami generation and propagation from combined earthquake and landslide sources. In this study, tsunami hazards are evaluated from both individual and combined cases of submarine earthquakes and landslides through numerical tsunami simulations with a grid size of 90 m for bathymetry and topography data for the entire Marmara Sea region and validated with historical observations from the 1509 and 1894 earthquakes. This study implements TUNAMI model with a two-layer model to conduct numerical tsunami simulations, and the numerical results show that the maximum tsunami height could reach 4.0 m along Istanbul shores for a full submarine rupture of the NAF, with a fault slip of 5.0 m in the eastern and western basins of the Marmara Sea. The maximum tsunami height for landslide-generated tsunamis from small, medium, and large of initial landslide volumes (0.15, 0.6, and 1.5 km3, respectively) could reach 3.5, 6.0, and 8.0 m, respectively, along Istanbul shores. Possible tsunamis from submarine landslides could be significantly higher than those from earthquakes, depending on the landslide volume significantly. These combined earthquake and landslide sources only result in higher tsunami amplitudes for small volumes significantly because of amplification within the same tsunami amplitude scale (3.0-4.0 m). Waveforms from all the coasts around the Marmara Sea

  14. Impact of Respiratory Motion on Worst-Case-Scenario Optimized Intensity-Modulated Proton Therapy for Lung Cancers

    PubMed Central

    Liu, Wei; Liao, Zhongxing; Schild, Steven E.; Liu, Zhong; Li, Heng; Li, Yupeng; Park, Peter C.; Li, Xiaoqiang; Stoker, Joshua; Shen, Jiajian; Keole, Sameer; Anand, Aman; Fatyga, Mirek; Dong, Lei; Sahoo, Narayan; Vora, Sujay; Wong, William; Zhu, X. Ronald; Bues, Martin; Mohan, Radhe

    2014-01-01

    Background We compared conventionally optimized intensity-modulated proton therapy (IMPT) treatment plans against the worst-case scenario optimized treatment plans for lung cancer. The comparison of the two IMPT optimization strategies focused on the resulting plans’ ability to retain dose objectives under the influence of patient set-up, inherent proton range uncertainty, and dose perturbation caused by respiratory motion. Methods For each of the 9 lung cancer cases two treatment plans were created accounting for treatment uncertainties in two different ways: the first used the conventional method: delivery of prescribed dose to the planning target volume (PTV) that is geometrically expanded from the internal target volume (ITV). The second employed the worst-case scenario optimization scheme that addressed set-up and range uncertainties through beamlet optimization. The plan optimality and plan robustness were calculated and compared. Furthermore, the effects on dose distributions of the changes in patient anatomy due to respiratory motion was investigated for both strategies by comparing the corresponding plan evaluation metrics at the end-inspiration and end-expiration phase and absolute differences between these phases. The mean plan evaluation metrics of the two groups were compared using two-sided paired t-tests. Results Without respiratory motion considered, we affirmed that worst-case scenario optimization is superior to PTV-based conventional optimization in terms of plan robustness and optimality. With respiratory motion considered, worst-case-scenario optimization still achieved more robust dose distributions to respiratory motion for targets and comparable or even better plan optimality [D95% ITV: 96.6% versus 96.1% (p=0.26), D5% − D95% ITV: 10.0% versus 12.3% (p=0.082), D1% spinal cord: 31.8% versus 36.5% (p =0.035)]. Conclusions Worst-case scenario optimization led to superior solutions for lung IMPT. Despite of the fact that worst-case-scenario

  15. Impact of respiratory motion on worst-case scenario optimized intensity modulated proton therapy for lung cancers.

    PubMed

    Liu, Wei; Liao, Zhongxing; Schild, Steven E; Liu, Zhong; Li, Heng; Li, Yupeng; Park, Peter C; Li, Xiaoqiang; Stoker, Joshua; Shen, Jiajian; Keole, Sameer; Anand, Aman; Fatyga, Mirek; Dong, Lei; Sahoo, Narayan; Vora, Sujay; Wong, William; Zhu, X Ronald; Bues, Martin; Mohan, Radhe

    2015-01-01

    We compared conventionally optimized intensity modulated proton therapy (IMPT) treatment plans against worst-case scenario optimized treatment plans for lung cancer. The comparison of the 2 IMPT optimization strategies focused on the resulting plans' ability to retain dose objectives under the influence of patient setup, inherent proton range uncertainty, and dose perturbation caused by respiratory motion. For each of the 9 lung cancer cases, 2 treatment plans were created that accounted for treatment uncertainties in 2 different ways. The first used the conventional method: delivery of prescribed dose to the planning target volume that is geometrically expanded from the internal target volume (ITV). The second used a worst-case scenario optimization scheme that addressed setup and range uncertainties through beamlet optimization. The plan optimality and plan robustness were calculated and compared. Furthermore, the effects on dose distributions of changes in patient anatomy attributable to respiratory motion were investigated for both strategies by comparing the corresponding plan evaluation metrics at the end-inspiration and end-expiration phase and absolute differences between these phases. The mean plan evaluation metrics of the 2 groups were compared with 2-sided paired Student t tests. Without respiratory motion considered, we affirmed that worst-case scenario optimization is superior to planning target volume-based conventional optimization in terms of plan robustness and optimality. With respiratory motion considered, worst-case scenario optimization still achieved more robust dose distributions to respiratory motion for targets and comparable or even better plan optimality (D95% ITV, 96.6% vs 96.1% [P = .26]; D5%- D95% ITV, 10.0% vs 12.3% [P = .082]; D1% spinal cord, 31.8% vs 36.5% [P = .035]). Worst-case scenario optimization led to superior solutions for lung IMPT. Despite the fact that worst-case scenario optimization did not explicitly account for

  16. Defining the worst case scenario for the Makran Subduction Zone: the 1008 AD tsunami

    NASA Astrophysics Data System (ADS)

    Hoffmann, Goesta

    2016-04-01

    correlated to the 1008 AD earthquake and tsunami inundation. The boulder deposits as well as the archaeological remains testify for a maximum tsunami runup of 15m, exceeding by far the inundation as observed in 1945. We define this as the worst case scenario for the Makran Subduction Zone. However, the return period is rather large (>500 years).

  17. Evacuation planning for plausible worst case inundation scenarios in Honolulu, Hawaii.

    PubMed

    Kim, Karl; Pant, Pradip; Yamashita, Eric

    2015-01-01

    Honolulu is susceptible to coastal flooding hazards. Like other coastal cities, Honolulu&s long-term economic viability and sustainability depends on how well it can adapt to changes in the natural and built environment. While there is a disagreement over the magnitude and extent of localized impacts associated with climate change, it is widely accepted that by 2100 there will be at least a meter in sea level rise (SLR) and an increase in extreme weather events. Increased exposure and vulnerabilities associated with urbanization and location of human activities in coastal areas warrants serious consideration by planners and policy makers. This article has three objectives. First, flooding due to the combined effects of SLR and episodic hydro-meteorological and geophysical events in Honolulu are investigated and the risks to the community are quantified. Second, the risks and vulnerabilities of critical infrastructure and the surface transportation system are described. Third, using the travel demand software, travel distances and travel times for evacuation from inundated areas are modeled. Data from three inundation models were used. The first model simulated storm surge from a category 4 hurricane similar to Hurricane Iniki which devastated the island of Kauai in 1992. The second model estimates inundation based on five tsunamis that struck Hawaii. A 1-m increase in sea level was included in both the hurricane storm surge and tsunami flooding models. The third model used in this article generated a 500-year flood event due to riverine flooding. Using a uniform grid cell structure, the three inundation maps were used to assess the worst case flooding scenario. Based on the flood depths, the ruling hazard (hurricane, tsunami, or riverine flooding) for each grid cell was determined. The hazard layer was analyzed with socioeconomic data layers to determine the impact on vulnerable populations, economic activity, and critical infrastructure. The analysis focused both

  18. Tsunami hazard in the Caribbean: Regional exposure derived from credible worst case scenarios

    NASA Astrophysics Data System (ADS)

    Harbitz, C. B.; Glimsdal, S.; Bazin, S.; Zamora, N.; Løvholt, F.; Bungum, H.; Smebye, H.; Gauer, P.; Kjekstad, O.

    2012-04-01

    The present study documents a high tsunami hazard in the Caribbean region, with several thousands of lives lost in tsunamis and associated earthquakes since the XIXth century. Since then, the coastal population of the Caribbean and the Central West Atlantic region has grown significantly and is still growing. Understanding this hazard is therefore essential for the development of efficient mitigation measures. To this end, we report a regional tsunami exposure assessment based on potential and credible seismic and non-seismic tsunamigenic sources. Regional tsunami databases have been compiled and reviewed, and on this basis five main scenarios have been selected to estimate the exposure. The scenarios comprise two Mw8 earthquake tsunamis (north of Hispaniola and east of Lesser Antilles), two subaerial/submarine volcano flank collapse tsunamis (Montserrat and Saint Lucia), and one tsunami resulting from a landslide on the flanks of the Kick'em Jenny submarine volcano (north of Grenada). Offshore tsunami water surface elevations as well as maximum water level distributions along the shore lines are computed and discussed for each of the scenarios. The number of exposed people has been estimated in each case, together with a summary of the tsunami exposure for the earthquake and the landslide tsunami scenarios. For the earthquake scenarios, the highest tsunami exposure relative to the population is found for Guadeloupe (6.5%) and Antigua (7.5%), while Saint Lucia (4.5%) and Antigua (5%) have been found to have the highest tsunami exposure relative to the population for the landslide scenarios. Such high exposure levels clearly warrant more attention on dedicated mitigation measures in the Caribbean region.

  19. 30 CFR 254.47 - Determining the volume of oil of your worst case discharge scenario.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... determining the daily discharge rate, you must consider reservoir characteristics, casing/production tubing sizes, and historical production and reservoir pressure data. Your scenario must discuss how to respond... uncontrolled blowout. In determining the daily discharge rate, you must consider any known...

  20. Worst case scenario

    SciTech Connect

    Broecker, W.S.

    1997-12-31

    Evidence from paleoarchives clearly demonstrates that the Earth`s climate system must have multiple states of operation which differ greatly in regional temperature, rainfall, and dustiness. Transitions between these states were abrupt occurring in a few decades. During the last 10,000 years, the Earth has been spared of these climate jumps. However during the previous 100,000 years, one such jump occurred two thousand or so years. To date, models of the ocean-atmosphere system have revealed that the oceans` thermohaline circulation is subject to mode switches. But none has captured the large globe-spanning atmospheric changes so clearly revealed in the records kept in ice and sediment. So in adding greenhouse gases to our atmosphere, we poke on ornery beast. Hopefully, this nudge will not cause climate to leap into another of its states.

  1. Worst-Case Scenario Tsunami Hazard Assessment in Two Historically and Economically Important Districts in Eastern Sicily (Italy)

    NASA Astrophysics Data System (ADS)

    Armigliato, A.; Tinti, S.; Pagnoni, G.; Zaniboni, F.; Paparo, M. A.

    2015-12-01

    The portion of the eastern Sicily coastline (southern Italy), ranging from the southern part of the Catania Gulf (to the north) down to the southern-eastern end of the island, represents a very important geographical domain from the industrial, commercial, military, historical and cultural points of view. Here the two major cities of Augusta and Siracusa are found. In particular, the Augusta bay hosts one of the largest petrochemical poles in the Mediterranean, and Siracusa is listed among the UNESCO World Heritage Sites since 2005. This area was hit by at least seven tsunamis in the approximate time interval from 1600 BC to present, the most famous being the 365, 1169, 1693 and 1908 tsunamis. The choice of this area as one of the sites for the testing of innovative methods for tsunami hazard, vulnerability and risk assessment and reduction is then fully justified. This is being developed in the frame of the EU Project called ASTARTE - Assessment, STrategy And Risk Reduction for Tsunamis in Europe (Grant 603839, 7th FP, ENV.2013.6.4-3). We assess the tsunami hazard for the Augusta-Siracusa area through the worst-case credible scenario technique, which can be schematically divided into the following steps: 1) Selection of five main source areas, both in the near- and in the far-field (Hyblaean-Malta escarpment, Messina Straits, Ionian subduction zone, Calabria offshore, western Hellenic Trench); 2) Choice of potential and credible tsunamigenic faults in each area: 38 faults were selected, with properly assigned magnitude, geometry and focal mechanism; 3) Computation of the maximum tsunami wave elevations along the eastern Sicily coast on a coarse grid (by means of the in-house code UBO-TSUFD) and extraction of the 9 scenarios that produce the largest effects in the target areas of Augusta and Siracusa; 4) For each of the 9 scenarios we run numerical UBO-TSUFD simulations over a set of five nested grids, with grid cells size decreasing from 3 km in the open Ionian

  2. The worst case scenario: Locomotor and collision demands of the longest periods of gameplay in professional rugby union

    PubMed Central

    Reardon, Cillian; Tobin, Daniel P.; Tierney, Peter; Delahunt, Eamonn

    2017-01-01

    A number of studies have used global positioning systems (GPS) to report on positional differences in the physical game demands of rugby union both on an average and singular bout basis. However, the ability of these studies to report quantitative data is limited by a lack of validation of certain aspects of measurement by GPS micro-technology. Furthermore no study has analyzed the positional physical demands of the longest bouts of ball-in-play time in rugby union. The aim of the present study is to compare the demands of the single longest period of ball-in-play, termed “worst case scenario” (WCS) between positional groups, which have previously been reported to have distinguishable game demands. The results of this study indicate that WCS periods follow a similar sporadic pattern as average demands but are played at a far higher pace than previously reported for average game demands with average meters per minute of 116.8 m. The positional differences in running and collision activity previously reported are perpetuated within WCS periods. Backs covered greater total distances than forwards (318 m vs 289 m), carried out more high-speed running (11.1 m·min-1 vs 5.5 m·min-1) and achieved higher maximum velocities (MaxVel). Outside Backs achieved the highest MaxVel values (6.84 m·sec-1). Tight Five and Back Row forwards underwent significantly more collisions than Inside Back and Outside Backs (0.73 & 0.89 collisions·min-1 vs 0.28 & 0.41 collisions·min-1 respectively). The results of the present study provide information on the positional physical requirements of performance in prolonged periods involving multiple high intensity bursts of effort. Although the current state of GPS micro-technology as a measurement tool does not permit reporting of collision intensity or acceleration data, the combined use of video and GPS provides valuable information to the practitioner. This can be used to match and replicate game demands in training. PMID:28510582

  3. EPHECT I: European household survey on domestic use of consumer products and development of worst-case scenarios for daily use.

    PubMed

    Dimitroulopoulou, C; Lucica, E; Johnson, A; Ashmore, M R; Sakellaris, I; Stranger, M; Goelen, E

    2015-12-01

    Consumer products are frequently and regularly used in the domestic environment. Realistic estimates for product use are required for exposure modelling and health risk assessment. This paper provides significant data that can be used as input for such modelling studies. A European survey was conducted, within the framework of the DG Sanco-funded EPHECT project, on the household use of 15 consumer products. These products are all-purpose cleaners, kitchen cleaners, floor cleaners, glass and window cleaners, bathroom cleaners, furniture and floor polish products, combustible air fresheners, spray air fresheners, electric air fresheners, passive air fresheners, coating products for leather and textiles, hair styling products, spray deodorants and perfumes. The analysis of the results from the household survey (1st phase) focused on identifying consumer behaviour patterns (selection criteria, frequency of use, quantities, period of use and ventilation conditions during product use). This can provide valuable input to modelling studies, as this information is not reported in the open literature. The above results were further analysed (2nd phase), to provide the basis for the development of 'most representative worst-case scenarios' regarding the use of the 15 products by home-based population groups (housekeepers and retired people), in four geographical regions in Europe. These scenarios will be used for the exposure and health risk assessment within the EPHECT project. To the best of our knowledge, it is the first time that daily worst-case scenarios are presented in the scientific published literature concerning the use of a wide range of 15 consumer products across Europe.

  4. Coupling atmospheric, hydrological and hydraulic models to develop a catalogue of worst-case scenarios for extreme flooding in Switzerland

    NASA Astrophysics Data System (ADS)

    José Gómez-Navarro, Juan; Felder, Guido; Raible, Christoph C.; Martius, Olivia; Rössler, Ole

    2015-04-01

    the high-resolution simulation (as it is driven by the boundary conditions provided by the GCM), the spatial structure of the precipitation is refined, producing stronger precipitation gradients that allow to identify the main orographic barriers. Further on, much higher precipitation rates occur in some river catchments, which are indicative of potential disastrous situations at very localised regions. In a next step, the results of the atmospheric-alone RCM simulations will be used to drive the hydrological model PREVAH. This model produces event hydrographs, that represent plausible catchment reactions on the simulated precipitation produced by the RCM. The event hydrographs will be then routed with the 1D/2D hydraulic model BASEMENT-ETH, that accounts for the retention effects of lakes and inundated areas. Hence, the described model chain will eventually simulate a number of physically plausible peak discharges in Switzerland that are determined by the most extreme situations occurring in the GCM simulation. This will enable the analysis and characterisation of worst-case floodings in Switzerland whose return period exceeds several centuries.

  5. Assessing oral bioaccessibility of trace elements in soils under worst-case scenarios by automated in-line dynamic extraction as a front end to inductively coupled plasma atomic emission spectrometry.

    PubMed

    Rosende, María; Magalhães, Luis M; Segundo, Marcela A; Miró, Manuel

    2014-09-09

    A novel biomimetic extraction procedure that allows for the in-line handing of ≥400 mg solid substrates is herein proposed for automatic ascertainment of trace element (TE) bioaccessibility in soils under worst-case conditions as per recommendations of ISO norms. A unified bioaccessibility/BARGE method (UBM)-like physiological-based extraction test is evaluated for the first time in a dynamic format for accurate assessment of in-vitro bioaccessibility of Cr, Cu, Ni, Pb and Zn in forest and residential-garden soils by on-line coupling of a hybrid flow set-up to inductively coupled plasma atomic emission spectrometry. Three biologically relevant operational extraction modes mimicking: (i) gastric juice extraction alone; (ii) saliva and gastric juice composite in unidirectional flow extraction format and (iii) saliva and gastric juice composite in a recirculation mode were thoroughly investigated. The extraction profiles of the three configurations using digestive fluids were proven to fit a first order reaction kinetic model for estimating the maximum TE bioaccessibility, that is, the actual worst-case scenario in human risk assessment protocols. A full factorial design, in which the sample amount (400-800 mg), the extractant flow rate (0.5-1.5 mL min(-1)) and the extraction temperature (27-37°C) were selected as variables for the multivariate optimization studies in order to obtain the maximum TE extractability. Two soils of varied physicochemical properties were analysed and no significant differences were found at the 0.05 significance level between the summation of leached concentrations of TE in gastric juice plus the residual fraction and the total concentration of the overall assayed metals determined by microwave digestion. These results showed the reliability and lack of bias (trueness) of the automatic biomimetic extraction approach using digestive juices.

  6. Anticipating and training for the worst-case metabolic scenario: a comment on Del Vecchio, Hirata, and Franchini (2011).

    PubMed

    Amtmann, John

    2012-02-01

    Del Vecchio, Hirata, and Franchini (2011) studied the effort: pause ratio of mixed martial arts by analyzing 26 bouts in two separate mixed martial arts events in Sao Paulo, Brazil. They referenced research identifying effort:pause ratios from other combat sports ranging from 10:1 (Brazilian Jiu Jitsu), 2:1 (judo and wrestling), and 1:3/1:4 (taekwondo). The authors identified an effort:pause ratio ranging from 1:2 to 1:4 in the bouts they analyzed, and suggested and described training programs that resemble this ratio. It is important for coaches to anticipate the most challenging metabolic mixed martial arts scenario and to create training programs that mimic that profile. Del Vecchio and associates' research is an important first step in gathering information which can help enhance training programs for injury prevention and performance enhancement.

  7. The Avellino 3780-yr-B.P. catastrophe as a worst-case scenario for a future eruption at Vesuvius

    PubMed Central

    Mastrolorenzo, Giuseppe; Petrone, Pierpaolo; Pappalardo, Lucia; Sheridan, Michael F.

    2006-01-01

    A volcanic catastrophe even more devastating than the famous anno Domini 79 Pompeii eruption occurred during the Old Bronze Age at Vesuvius. The 3780-yr-B.P. Avellino plinian eruption produced an early violent pumice fallout and a late pyroclastic surge sequence that covered the volcano surroundings as far as 25 km away, burying land and villages. Here we present the reconstruction of this prehistoric catastrophe and its impact on the Bronze Age culture in Campania, drawn from an interdisciplinary volcanological and archaeoanthropological study. Evidence shows that a sudden, en masse evacuation of thousands of people occurred at the beginning of the eruption, before the last destructive plinian column collapse. Most of the fugitives likely survived, but the desertification of the total habitat due to the huge eruption size caused a social–demographic collapse and the abandonment of the entire area for centuries. Because an event of this scale is capable of devastating a broad territory that includes the present metropolitan district of Naples, it should be considered as a reference for the worst eruptive scenario at Vesuvius. PMID:16537390

  8. The Avellino 3780-yr-B.P. catastrophe as a worst-case scenario for a future eruption at Vesuvius.

    PubMed

    Mastrolorenzo, Giuseppe; Petrone, Pierpaolo; Pappalardo, Lucia; Sheridan, Michael F

    2006-03-21

    A volcanic catastrophe even more devastating than the famous anno Domini 79 Pompeii eruption occurred during the Old Bronze Age at Vesuvius. The 3780-yr-B.P. Avellino plinian eruption produced an early violent pumice fallout and a late pyroclastic surge sequence that covered the volcano surroundings as far as 25 km away, burying land and villages. Here we present the reconstruction of this prehistoric catastrophe and its impact on the Bronze Age culture in Campania, drawn from an interdisciplinary volcanological and archaeoanthropological study. Evidence shows that a sudden, en masse evacuation of thousands of people occurred at the beginning of the eruption, before the last destructive plinian column collapse. Most of the fugitives likely survived, but the desertification of the total habitat due to the huge eruption size caused a social-demographic collapse and the abandonment of the entire area for centuries. Because an event of this scale is capable of devastating a broad territory that includes the present metropolitan district of Naples, it should be considered as a reference for the worst eruptive scenario at Vesuvius.

  9. Assessing tsunami hazard for the town of Varna (Bulgaria) by means of a worst-case scenario approach

    NASA Astrophysics Data System (ADS)

    Tinti, S.; Pagnoni, G.; Armigliato, A.; Tonini, R.; Ranguelov, B.

    2012-04-01

    Although the tsunami hazard in the Black Sea is not comparable to other regions of the Euro-Mediterranean area, nonetheless tsunami catalogues indicate that it is far from being negligible as several historical events were recorded, some of which being locally damaging. Taking advantage of the results produced by the EU-FP6 TRANSFER project, which studied the tsunami hazard for the entire Black Sea starting from different tectonic sources located throughout the basin, we focus on the Bulgarian coasts and in particular on the coastal city of Varna, which is the third as regards population in Bulgaria and represents an important economic and touristic centre. We selected two tectonic sources placed just offshore the NE coast of Bulgaria (where Varna is located), sharing the same fault parameters except for the strike (90° and 40° respectively), one being almost parallel to the coast, the other intersecting the coast itself. The maximum expected magnitude for these faults is 7.5. We compute inundation maps by means of the in-house finite-differences shallow-water code UBO-TSUFD. We exploited a quite detailed topographic DEM of the city of Varna to build nested computational grids with resolutions resulting from a compromise between the DEM itself and the bathymetry data available close to the Bulgarian coast. The maximum values of water elevation, current speed, flow depth and momentum flux are calculated for each case and implemented in suitable maps. The last step of the work consists in building aggregated fields, i.e. maps obtained by combining the two different scenarios and taking the maximum of the relevant computed physical parameters in each grid node. These results will be used in a later work to integrate preliminary tsunami vulnerability and risk analyses focussed on Varna that were conducted in the frame of the EU-FP6 SCHEMA project.

  10. Geochemical modelling of worst-case leakage scenarios at potential CO2-storage sites - CO2 and saline water contamination of drinking water aquifers

    NASA Astrophysics Data System (ADS)

    Szabó, Zsuzsanna; Edit Gál, Nóra; Kun, Éva; Szőcs, Teodóra; Falus, György

    2017-04-01

    Carbon Capture and Storage is a transitional technology to reduce greenhouse gas emissions and to mitigate climate change. Following the implementation and enforcement of the 2009/31/EC Directive in the Hungarian legislation, the Geological and Geophysical Institute of Hungary is required to evaluate the potential CO2 geological storage structures of the country. Basic assessment of these saline water formations has been already performed and the present goal is to extend the studies to the whole of the storage complex and consider the protection of fresh water aquifers of the neighbouring area even in unlikely scenarios when CO2 injection has a much more regional effect than planned. In this work, worst-case scenarios are modelled to understand the effects of CO2 or saline water leaks into drinking water aquifers. The dissolution of CO2 may significantly change the pH of fresh water which induces mineral dissolution and precipitation in the aquifer and therefore, changes in solution composition and even rock porosity. Mobilization of heavy metals may also be of concern. Brine migration from CO2 reservoir and replacement of fresh water in the shallower aquifer may happen due to pressure increase as a consequence of CO2 injection. The saline water causes changes in solution composition which may also induce mineral reactions. The modelling of the above scenarios has happened at several methodological levels such as equilibrium batch, kinetic batch and kinetic reactive transport simulations. All of these have been performed by PHREEQC using the PHREEQC.DAT thermodynamic database. Kinetic models use equations and kinetic rate parameters from the USGS report of Palandri and Kharaka (2004). Reactive transport modelling also considers estimated fluid flow and dispersivity of the studied formation. Further input parameters are the rock and the original ground water compositions of the aquifers and a range of gas-phase CO2 or brine replacement ratios. Worst-case scenarios

  11. Worst-case scenario approach to the tsunami hazard assessment for the coastal areas between Augusta and Siracusa, eastern Sicily, Italy

    NASA Astrophysics Data System (ADS)

    Armigliato, Alberto; Pagnoni, Gianluca; Zaniboni, Filippo; Tinti, Stefano

    2015-04-01

    The province of Siracusa encompasses a very long portion of the eastern Sicily coastline, ranging from the southern part of the Catania Gulf to the north down to the southern-eastern end of the island, known as Capo Passero. Within this domain, the area comprised between the towns of Augusta and Siracusa has been selected as one of the sites for the testing of innovative methods for tsunami hazard, vulnerability and risk assessment and reduction developed in the frame of the EU Project called ASTARTE - Assessment, STrategy And Risk Reduction for Tsunamis in Europe (Grant 603839, 7th FP, ENV.2013.6.4-3). The selection was driven by two main reasons. First, the area was hit by at least seven tsunamis in the approximate time interval from 1600 BC to present, as can be deduced from historical catalogues and paleo-tsunami deposits analysis: the most famous are probably the 21 July 365, 4 February 1169, 11 January 1693 and 28 December 1908 tsunamis. Secondly, as a whole, the test site has a strong relevance from the industrial, commercial, military, historical and cultural points of view: here it is sufficient to mention the huge petrochemical pole in the Augusta bay and the listing of Siracusa as UNESCO World Heritage Site since 2005. This contribution deals with the tsunami hazard assessment for the Augusta-Siracusa area, approached through the worst-case credible scenario technique. We selected five main source areas: the choice is driven mainly by the already mentioned fact that historical catalogues and paleo-tsunami studies tell us that the area under investigation can be impacted by tsunamis generated both in the near-field and in the far-field. The five areas include the Hyblaean-Malta escarpment and the Messina Straits in the near-field, the western and eastern lobes of the Ionian subduction zone in the intermediate field, and the western Hellenic Trench in the far-field. In each source area, a selection of possible faults was made, whose characteristics and

  12. A critical evaluation of worst case optimization methods for robust intensity-modulated proton therapy planning

    SciTech Connect

    Fredriksson, Albin Bokrantz, Rasmus

    2014-08-15

    Purpose: To critically evaluate and compare three worst case optimization methods that have been previously employed to generate intensity-modulated proton therapy treatment plans that are robust against systematic errors. The goal of the evaluation is to identify circumstances when the methods behave differently and to describe the mechanism behind the differences when they occur. Methods: The worst case methods optimize plans to perform as well as possible under the worst case scenario that can physically occur (composite worst case), the combination of the worst case scenarios for each objective constituent considered independently (objectivewise worst case), and the combination of the worst case scenarios for each voxel considered independently (voxelwise worst case). These three methods were assessed with respect to treatment planning for prostate under systematic setup uncertainty. An equivalence with probabilistic optimization was used to identify the scenarios that determine the outcome of the optimization. Results: If the conflict between target coverage and normal tissue sparing is small and no dose-volume histogram (DVH) constraints are present, then all three methods yield robust plans. Otherwise, they all have their shortcomings: Composite worst case led to unnecessarily low plan quality in boundary scenarios that were less difficult than the worst case ones. Objectivewise worst case generally led to nonrobust plans. Voxelwise worst case led to overly conservative plans with respect to DVH constraints, which resulted in excessive dose to normal tissue, and less sharp dose fall-off than the other two methods. Conclusions: The three worst case methods have clearly different behaviors. These behaviors can be understood from which scenarios that are active in the optimization. No particular method is superior to the others under all circumstances: composite worst case is suitable if the conflicts are not very severe or there are DVH constraints whereas

  13. 41 CFR 102-80.150 - What is meant by “reasonable worst case fire scenario”?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-SAFETY AND ENVIRONMENTAL MANAGEMENT Accident and Fire Prevention Reasonable Worst Case Fire Scenario... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is meant by âreasonable worst case fire scenarioâ? 102-80.150 Section 102-80.150 Public Contracts and Property Management...

  14. Less than severe worst case accidents

    SciTech Connect

    Sanders, G.A.

    1996-08-01

    Many systems can provide tremendous benefit if operating correctly, produce only an inconvenience if they fail to operate, but have extreme consequences if they are only partially disabled such that they operate erratically or prematurely. In order to assure safety, systems are often tested against the most severe environments and accidents that are considered possible to ensure either safe operation or safe failure. However, it is often the less severe environments which result in the ``worst case accident`` since these are the conditions in which part of the system may be exposed or rendered unpredictable prior to total system failure. Some examples of less severe mechanical, thermal, and electrical environments which may actually be worst case are described as cautions for others in industries with high consequence operations or products.

  15. Specifying design conservatism: Worst case versus probabilistic analysis

    NASA Technical Reports Server (NTRS)

    Miles, Ralph F., Jr.

    1993-01-01

    Design conservatism is the difference between specified and required performance, and is introduced when uncertainty is present. The classical approach of worst-case analysis for specifying design conservatism is presented, along with the modern approach of probabilistic analysis. The appropriate degree of design conservatism is a tradeoff between the required resources and the probability and consequences of a failure. A probabilistic analysis properly models this tradeoff, while a worst-case analysis reveals nothing about the probability of failure, and can significantly overstate the consequences of failure. Two aerospace examples will be presented that illustrate problems that can arise with a worst-case analysis.

  16. Worst case optimization for interfractional motion mitigation in carbon ion therapy of pancreatic cancer.

    PubMed

    Steitz, Julian; Naumann, Patrick; Ulrich, Silke; Haefner, Matthias F; Sterzing, Florian; Oelfke, Uwe; Bangert, Mark

    2016-10-07

    The efficacy of radiation therapy treatments for pancreatic cancer is compromised by abdominal motion which limits the spatial accuracy for dose delivery - especially for particles. In this work we investigate the potential of worst case optimization for interfractional offline motion mitigation in carbon ion treatments of pancreatic cancer. We implement a worst case optimization algorithm that explicitly models the relative biological effectiveness of carbon ions during inverse planning. We perform a comparative treatment planning study for seven pancreatic cancer patients. Treatment plans that have been generated using worst case optimization are compared against (1) conventional intensity-modulated carbon ion therapy, (2) single field uniform dose carbon ion therapy, and (3) an ideal yet impractical scenario relying on daily re-planning. The dosimetric quality and robustness of the resulting treatment plans is evaluated using reconstructions of the daily delivered dose distributions on fractional control CTs. Idealized daily re-planning consistently gives the best dosimetric results with regard to both target coverage and organ at risk sparing. The absolute reduction of D 95 within the gross tumor volume during fractional dose reconstruction is most pronounced for conventional intensity-modulated carbon ion therapy. Single field uniform dose optimization exhibits no substantial reduction for six of seven patients and values for D 95 for worst case optimization fall in between. The treated volume (D>95 % prescription dose) outside of the gross tumor volume is reduced by a factor of two by worst case optimization compared to conventional optimization and single field uniform dose optimization. Single field uniform dose optimization comes at an increased radiation exposure of normal tissues, e.g. ≈2 Gy (RBE) in the mean dose in the kidneys compared to conventional and worst case optimization and ≈4 Gy (RBE) in D 1 in the spinal cord compared to worst case

  17. Spacecraft electrical potential estimation in worst case environment

    NASA Astrophysics Data System (ADS)

    Toyoda, Kazuhiro

    2016-07-01

    There are no established simulation criteria for the space environment that produces the worst-case spacecraft charging. An ISO New Work Item Proposal entitled Potential Estimation in Worst-Case Environments was approved for ISO TC20/SC14/WG4. One of the aims of this project is to establish a worst-case charging environment for spacecraft charging simulation. In this paper, we compare round-robin simulations using the MUSCAT and Nascap-2k spacecraft charging codes and published measured worst-case GEO charging environments. As originally envisioned, the SPIS code was also to be part of the round-robin. However, SPIS code results are not available at this time. Thus, in this paper, MUSCAT results are compared with Nascap-2k results. In the round-robin simulation, the same spacecraft model is used with the same material properties and simulations are done with the same environments. Finally our round-robin simulation results suggest the worst-case charging GEO spacecraft charging environment that may be used for spacecraft modeling, design, and testing.

  18. Worst-Case Test Conditions of SEGR for Power DMOSFETs

    NASA Astrophysics Data System (ADS)

    Liu, Sandra; Titus, Jeffrey L.; Zafrani, Max; Cao, Huy; Carrier, Douglas; Sherman, Phillip

    2010-02-01

    Heavy ion test results show worst-case test conditions for single-event gate rupture (SEGR) of power MOSFETs. Contrary to common belief, the worst-case ion condition for SEGR is not the ion with the deepest penetration depth in the device or highest LET at the die surface, but the ion beams with Bragg peak positioned at or near the interface of the epitaxial layer and the highly doped substrate. The factors that have significant impact on SEGR thresholds are evaluated and discussed. The factors that are considered include: ion beam, drain bias, gate bias, ion species, ion range, surface LET and the construction layer of the power DMOSFET. An estimated worst-case ion range table for krypton, xenon and gold is provided for reference.

  19. Development of worst case meteorology criteria. Final report

    SciTech Connect

    Nokes, W.A.; Benson, P.E.

    1985-11-01

    A meteorological severity index (MSI) representing the relationship between meteorological parameters that contribute to worst-case carbon monoxide concentrations near roadways is described. The MSI is based on sensitivity studies of the California Lines Source Dispersion Model, CALINE4. Meteorological data collected at several monitoring sites throughout California are described. Probabilistic analysis of the monitoring data (stratified by geography and time-of-day) is combined with the MSI to develop worst-case meteorology inputs for estimating 1-hour CO levels using CALINE4. Guidelines are presented to help CALINE4 users develop or estimate an appropriate persistence factor for a project location. The probabilistic method described in the report can be used to establish new worst-case meteorology criteria in the event of changes in the number of exceedances allowed by the National Ambient Air Quality Standards. The variety of locations studied in California should make results of the study usable by other states.

  20. 49 CFR 194.105 - Worst case discharge.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the volume. (b) The worst case discharge is the largest volume, in barrels (cubic meters), of the... capacity of the pipeline), plus the largest line drainage volume after shutdown of the line section(s) in the response zone expressed in barrels (cubic meters); or (2) The largest foreseeable discharge...

  1. Improved worst-case and liely accident definition in complex facilities for 40 CFR 68 compliance

    SciTech Connect

    O`Kula, K.R., Taylor, Robert P., Jr; Hang, P.

    1997-04-01

    Many DOE facilities potentially subject to compliance with offsite consequence criteria under the 40 CFR 68 Risk Management Program house significant inventories of toxic and flammable chemicals. The accident progression event tree methodology is suggested as a useful technical basis to define Worst-Case and Alternative Release Scenarios in facilities performing operations beyond simple storage and/or having several barriers between the chemical hazard and the environment. For multiple chemical release scenarios, a chemical mixture methodology should be applied to conservatively define concentration isopleths. In some instances, the region requiring emergency response planning is larger under this approach than if chemicals are treated individually.

  2. 41 CFR 102-80.150 - What is meant by “reasonable worst case fire scenario”?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What is meant by âreasonable worst case fire scenarioâ? 102-80.150 Section 102-80.150 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY...

  3. Worst case estimation of homology design by convex analysis

    NASA Technical Reports Server (NTRS)

    Yoshikawa, N.; Elishakoff, Isaac; Nakagiri, S.

    1998-01-01

    The methodology of homology design is investigated for optimum design of advanced structures. for which the achievement of delicate tasks by the aid of active control system is demanded. The proposed formulation of homology design, based on the finite element sensitivity analysis, necessarily requires the specification of external loadings. The formulation to evaluate the worst case for homology design caused by uncertain fluctuation of loadings is presented by means of the convex model of uncertainty, in which uncertainty variables are assigned to discretized nodal forces and are confined within a conceivable convex hull given as a hyperellipse. The worst case of the distortion from objective homologous deformation is estimated by the Lagrange multiplier method searching the point to maximize the error index on the boundary of the convex hull. The validity of the proposed method is demonstrated in a numerical example using the eleven-bar truss structure.

  4. On the worst case uncertainty and its evaluation

    NASA Astrophysics Data System (ADS)

    Fabbiano, L.; Giaquinto, N.; Savino, M.; Vacca, G.

    2016-02-01

    The paper is a review on the worst case uncertainty (WCU) concept, neglected in the Guide to the Expression of Uncertainty in Measurements (GUM), but necessary for a correct uncertainty assessment in a number of practical cases involving distribution with compact support. First, it is highlighted that the knowledge of the WCU is necessary to choose a sensible coverage factor, associated to a sensible coverage probability: the Maximum Acceptable Coverage Factor (MACF) is introduced as a convenient index to guide this choice. Second, propagation rules for the worst-case uncertainty are provided in matrix and scalar form. It is highlighted that when WCU propagation cannot be computed, the Monte Carlo approach is the only way to obtain a correct expanded uncertainty assessment, in contrast to what can be inferred from the GUM. Third, examples of applications of the formulae to ordinary instruments and measurements are given. Also an example taken from the GUM is discussed, underlining some inconsistencies in it.

  5. Worst case estimation of homology design by convex analysis

    NASA Technical Reports Server (NTRS)

    Yoshikawa, N.; Elishakoff, Isaac; Nakagiri, S.

    1998-01-01

    The methodology of homology design is investigated for optimum design of advanced structures. for which the achievement of delicate tasks by the aid of active control system is demanded. The proposed formulation of homology design, based on the finite element sensitivity analysis, necessarily requires the specification of external loadings. The formulation to evaluate the worst case for homology design caused by uncertain fluctuation of loadings is presented by means of the convex model of uncertainty, in which uncertainty variables are assigned to discretized nodal forces and are confined within a conceivable convex hull given as a hyperellipse. The worst case of the distortion from objective homologous deformation is estimated by the Lagrange multiplier method searching the point to maximize the error index on the boundary of the convex hull. The validity of the proposed method is demonstrated in a numerical example using the eleven-bar truss structure.

  6. Worst-case-based robust beamforming for wireless cooperative networks

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Chen, Haihua; He, Ming

    2014-12-01

    It is known that distributed beamforming techniques can improve the performance of relay networks by using channel state information (CSI). In practical applications, there exist unavoidably estimation errors of the CSI, which results in outage of quality of service (QoS) or overconsumption of transmit power. In this paper, we propose two worst-case-based distributed beamforming techniques that are robust to the channel estimation errors. In the worst-case-based approaches, the worst case in a set that includes the actual case is optimized. Therefore, the performance of the actual case can be guaranteed. In our first approach, the maximal total relay transmit power in the set is minimized subject to the QoS constraint. This distributed beamforming problem can be approximately solved using second-order cone programming (SOCP). In our second method, the worst QoS in the set is maximized subject to the constraints of individual relay transmit powers. It is shown that the resultant problem can be approximately formulated as a quasi-convex problem and can be solved by using a bisection search method. Simulation results show that the proposed beamforming techniques are robust to the CSI errors and there is no outage of QoS or power in the proposed methods.

  7. On the estimation of the worst-case implant-induced RF-heating in multi-channel MRI.

    PubMed

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2017-03-02

    The increasing use of multiple radiofrequency (RF) transmit channels in magnetic resonance imaging (MRI) systems makes it necessary to rigorously assess the risk of RF-induced heating. This risk is especially aggravated with inclusions of medical implants within the body. The worst-case RF-heating scenario is achieved when the local tissue deposition in the at-risk region (generally in the vicinity of the implant electrodes) reaches its maximum value while MRI exposure is compliant with predefined general specific absorption rate (SAR) limits or power requirements. This work first reviews the common approach to estimate the worst-case RF-induced heating in multi-channel MRI environment, based on the maximization of the ratio of two Hermitian forms by solving a generalized eigenvalue problem. It is then shown that the common approach is not rigorous and may lead to an underestimation of the worst-case RF-heating scenario when there is a large number of RF transmit channels and there exist multiple SAR or power constraints to be satisfied. Finally, this work derives a rigorous SAR-based formulation to estimate a preferable worst-case scenario, which is solved by casting a semidefinite programming relaxation of this original non-convex problem, whose solution closely approximates the true worst-case including all SAR constraints. Numerical results for 2, 4, 8, 16, and 32 RF channels in a 3T-MRI volume coil for a patient with a deep-brain stimulator under a head imaging exposure are provided as illustrative examples.

  8. On the estimation of the worst-case implant-induced RF-heating in multi-channel MRI

    NASA Astrophysics Data System (ADS)

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2017-06-01

    The increasing use of multiple radiofrequency (RF) transmit channels in magnetic resonance imaging (MRI) systems makes it necessary to rigorously assess the risk of RF-induced heating. This risk is especially aggravated with inclusions of medical implants within the body. The worst-case RF-heating scenario is achieved when the local tissue deposition in the at-risk region (generally in the vicinity of the implant electrodes) reaches its maximum value while MRI exposure is compliant with predefined general specific absorption rate (SAR) limits or power requirements. This work first reviews the common approach to estimate the worst-case RF-induced heating in multi-channel MRI environment, based on the maximization of the ratio of two Hermitian forms by solving a generalized eigenvalue problem. It is then shown that the common approach is not rigorous and may lead to an underestimation of the worst-case RF-heating scenario when there is a large number of RF transmit channels and there exist multiple SAR or power constraints to be satisfied. Finally, this work derives a rigorous SAR-based formulation to estimate a preferable worst-case scenario, which is solved by casting a semidefinite programming relaxation of this original non-convex problem, whose solution closely approximates the true worst-case including all SAR constraints. Numerical results for 2, 4, 8, 16, and 32 RF channels in a 3T-MRI volume coil for a patient with a deep-brain stimulator under a head imaging exposure are provided as illustrative examples.

  9. What is the Worst Case for Cavity Decoupling?

    NASA Astrophysics Data System (ADS)

    Leith, W.

    2001-05-01

    A central issue for nuclear monitoring is the possibility that a nuclear test could be conducted while evading identification by international and national monitoring systems. Of several proposed evasion scenarios, decoupling an explosion in a large, deep, underground cavity has received considerable attention. While improvements in monitoring networks and technologies have decreased the event detection threshold in many regions, achievements in underground construction have also increased the feasibility of constructing large caverns that could conceivably be used for nuclear explosion decoupling. The yield range of greatest uncertainty lies between 1 and 10 kt, where underground explosions could be decoupled in salt and perhaps in hard rock. Assuming that full decoupling can be achieved in elongated cavities of moderate aspect ratio (up to 10:1), I have reviewed the literature on large-cavern construction in hard rock and salt (including cost), and the containment of nuclear explosions in these media, with the goal of defining the worst case for cavity decoupling. In thick salt deposits and domes, it is feasible to construct stable cavities of sufficient volume for full decoupling of nuclear tests larger than 10 kt. Salt probably provides an ideal environment for both cavity construction and containment, and it is possible that the cavity would not leak radioactivity for years. However, at 10 kt, the resulting seismic event would be detected and probably identified by regional monitoring networks. Suitable salt deposits are relatively rare and are not present in many countries of nuclear proliferation concern. Salt regions can usually be identified in the literature and by remote sensing, and could conceivably be monitored. In hard rock, construction of cavities of sufficient volume for full decoupling is limited to at most about 10 kt, mainly because of the difficulty in constructing a cavern of sufficient size at depths required for containment, and the

  10. Worst case analysis: Earth sensor assembly for the tropical rainfall measuring mission observatory

    NASA Technical Reports Server (NTRS)

    Conley, Michael P.

    1993-01-01

    This worst case analysis verifies that the TRMMESA electronic design is capable of maintaining performance requirements when subjected to worst case circuit conditions. The TRMMESA design is a proven heritage design and capable of withstanding the most worst case and adverse of circuit conditions. Changes made to the baseline DMSP design are relatively minor and do not adversely effect the worst case analysis of the TRMMESA electrical design.

  11. Measuring worst-case errors in a robot workcell

    SciTech Connect

    Simon, R.W.; Brost, R.C.; Kholwadwala, D.K.

    1997-10-01

    Errors in model parameters, sensing, and control are inevitably present in real robot systems. These errors must be considered in order to automatically plan robust solutions to many manipulation tasks. Lozano-Perez, Mason, and Taylor proposed a formal method for synthesizing robust actions in the presence of uncertainty; this method has been extended by several subsequent researchers. All of these results presume the existence of worst-case error bounds that describe the maximum possible deviation between the robot`s model of the world and reality. This paper examines the problem of measuring these error bounds for a real robot workcell. These measurements are difficult, because of the desire to completely contain all possible deviations while avoiding bounds that are overly conservative. The authors present a detailed description of a series of experiments that characterize and quantify the possible errors in visual sensing and motion control for a robot workcell equipped with standard industrial robot hardware. In addition to providing a means for measuring these specific errors, these experiments shed light on the general problem of measuring worst-case errors.

  12. Preliminary Analysis of Aircraft Loss of Control Accidents: Worst Case Precursor Combinations and Temporal Sequencing

    NASA Technical Reports Server (NTRS)

    Belcastro, Christine M.; Groff, Loren; Newman, Richard L.; Foster, John V.; Crider, Dennis H.; Klyde, David H.; Huston, A. McCall

    2014-01-01

    Aircraft loss of control (LOC) is a leading cause of fatal accidents across all transport airplane and operational classes, and can result from a wide spectrum of hazards, often occurring in combination. Technologies developed for LOC prevention and recovery must therefore be effective under a wide variety of conditions and uncertainties, including multiple hazards, and their validation must provide a means of assessing system effectiveness and coverage of these hazards. This requires the definition of a comprehensive set of LOC test scenarios based on accident and incident data as well as future risks. This paper defines a comprehensive set of accidents and incidents over a recent 15 year period, and presents preliminary analysis results to identify worst-case combinations of causal and contributing factors (i.e., accident precursors) and how they sequence in time. Such analyses can provide insight in developing effective solutions for LOC, and form the basis for developing test scenarios that can be used in evaluating them. Preliminary findings based on the results of this paper indicate that system failures or malfunctions, crew actions or inactions, vehicle impairment conditions, and vehicle upsets contributed the most to accidents and fatalities, followed by inclement weather or atmospheric disturbances and poor visibility. Follow-on research will include finalizing the analysis through a team consensus process, defining future risks, and developing a comprehensive set of test scenarios with correlation to the accidents, incidents, and future risks. Since enhanced engineering simulations are required for batch and piloted evaluations under realistic LOC precursor conditions, these test scenarios can also serve as a high-level requirement for defining the engineering simulation enhancements needed for generating them.

  13. SU-E-T-551: PTV Is the Worst-Case of CTV in Photon Therapy

    SciTech Connect

    Harrington, D; Liu, W; Park, P; Mohan, R

    2014-06-01

    Purpose: To examine the supposition of the static dose cloud and adequacy of the planning target volume (PTV) dose distribution as the worst-case representation of clinical target volume (CTV) dose distribution for photon therapy in head and neck (H and N) plans. Methods: Five diverse H and N plans clinically delivered at our institution were selected. Isocenter for each plan was shifted positively and negatively in the three cardinal directions by a displacement equal to the PTV expansion on the CTV (3 mm) for a total of six shifted plans per original plan. The perturbed plan dose was recalculated in Eclipse (AAA v11.0.30) using the same, fixed fluence map as the original plan. The dose distributions for all plans were exported from the treatment planning system to determine the worst-case CTV dose distributions for each nominal plan. Two worst-case distributions, cold and hot, were defined by selecting the minimum or maximum dose per voxel from all the perturbed plans. The resulting dose volume histograms (DVH) were examined to evaluate the worst-case CTV and nominal PTV dose distributions. Results: Inspection demonstrates that the CTV DVH in the nominal dose distribution is indeed bounded by the CTV DVHs in the worst-case dose distributions. Furthermore, comparison of the D95% for the worst-case (cold) CTV and nominal PTV distributions by Pearson's chi-square test shows excellent agreement for all plans. Conclusion: The assumption that the nominal dose distribution for PTV represents the worst-case dose distribution for CTV appears valid for the five plans under examination. Although the worst-case dose distributions are unphysical since the dose per voxel is chosen independently, the cold worst-case distribution serves as a lower bound for the worst-case possible CTV coverage. Minor discrepancies between the nominal PTV dose distribution and worst-case CTV dose distribution are expected since the dose cloud is not strictly static. This research was supported by

  14. Worst-Case Flutter Margins from F/A-18 Aircraft Aeroelastic Data

    NASA Technical Reports Server (NTRS)

    Lind, Rick; Brenner, Marty

    1997-01-01

    An approach for computing worst-case flutter margins has been formulated in a robust stability framework. Uncertainty operators are included with a linear model to describe modeling errors and flight variations. The structured singular value, micron, computes a stability margin which directly accounts for these uncertainties. This approach introduces a new method of computing flutter margins and an associated new parameter for describing these margins. The micron margins are robust margins which indicate worst-case stability estimates with respect to the defined uncertainty. Worst-case flutter margins are computed for the F/A-18 SRA using uncertainty sets generated by flight data analysis. The robust margins demonstrate flight conditions for flutter may lie closer to the flight envelope than previously estimated by p-k analysis.

  15. 30 CFR 254.47 - Determining the volume of oil of your worst case discharge scenario.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... effect of hydrostatic pressure, gravity, frictional wall forces and other factors; and (3) The daily... by taking into account the effects of hydrostatic pressure, gravity, frictional wall forces,...

  16. 30 CFR 254.47 - Determining the volume of oil of your worst case discharge scenario.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... effect of hydrostatic pressure, gravity, frictional wall forces and other factors; and (3) The daily... by taking into account the effects of hydrostatic pressure, gravity, frictional wall forces,...

  17. 40 CFR 68.25 - Worst-case release scenario analysis.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., vaporizes resulting in a vapor cloud explosion. A yield factor of 10 percent of the available energy... cloud explosion. (2) For flammable gases handled as refrigerated liquids at ambient pressure: (i) If the... substance is released as a gas in 10 minutes, and the total quantity will be involved in the vapor cloud...

  18. 40 CFR 68.25 - Worst-case release scenario analysis.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., vaporizes resulting in a vapor cloud explosion. A yield factor of 10 percent of the available energy... cloud explosion. (2) For flammable gases handled as refrigerated liquids at ambient pressure: (i) If the... substance is released as a gas in 10 minutes, and the total quantity will be involved in the vapor cloud...

  19. 40 CFR 68.25 - Worst-case release scenario analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., vaporizes resulting in a vapor cloud explosion. A yield factor of 10 percent of the available energy... cloud explosion. (2) For flammable gases handled as refrigerated liquids at ambient pressure: (i) If the... substance is released as a gas in 10 minutes, and the total quantity will be involved in the vapor cloud...

  20. Internet Posting of Chemical "Worst Case" Scenarios: A Roadmap for Terrorists

    DTIC Science & Technology

    1999-02-10

    with homework and connect with friends. As a parent, the greatest concern I used to have about the Internet was porn and the other things that sickos...slightest risk with the lives of their husbands, wives, parents, children , or grandchildren.’’ Let me stress that no one here, including those in law...make sure our standards cover the uncommon person who would be more sus- ceptible. This not only includes children , but also groups or individuals

  1. 40 CFR 68.25 - Worst-case release scenario analysis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... pool. The volatilization rate (release rate) shall be calculated at the boiling point of the substance... volatilization rate (release rate) shall be calculated at the boiling point of the substance and at the... below their atmospheric boiling point, the volatilization rate shall be calculated at the...

  2. 40 CFR 68.25 - Worst-case release scenario analysis.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pool. The volatilization rate (release rate) shall be calculated at the boiling point of the substance... volatilization rate (release rate) shall be calculated at the boiling point of the substance and at the... below their atmospheric boiling point, the volatilization rate shall be calculated at the...

  3. 30 CFR 254.47 - Determining the volume of oil of your worst case discharge scenario.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... capacity of all oil storage tanks and flow lines on the facility. Flow line volume may be estimated; and (2... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Determining the volume of oil of your worst..., REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL-SPILL RESPONSE REQUIREMENTS...

  4. Pediatric disaster preparedness: best planning for the worst-case scenario.

    PubMed

    Cicero, Mark X; Baum, Carl R

    2008-07-01

    Natural and man-made disasters are unpredictable but certainly will include children as victims. Increasingly, knowledge of pediatric disaster preparedness is required of emergency and primary care practitioners. A complete pediatric disaster plan comprises the following elements: appropriate personnel and equipment, disaster- and venue-specific training, and family preparedness. Disaster preparedness exercises are crucial for training plan implementation and response evaluation. Exercise content depends on local hazard vulnerabilities and learner training needs. Postexercise evaluations follow a stepwise process that culminates in improved disaster plans. This article will review disaster planning and the design, implementation, and evaluation of pediatric disaster exercises.

  5. The Worst-Case Weighted Multi-Objective Game with an Application to Supply Chain Competitions.

    PubMed

    Qu, Shaojian; Ji, Ying

    2016-01-01

    In this paper, we propose a worst-case weighted approach to the multi-objective n-person non-zero sum game model where each player has more than one competing objective. Our "worst-case weighted multi-objective game" model supposes that each player has a set of weights to its objectives and wishes to minimize its maximum weighted sum objectives where the maximization is with respect to the set of weights. This new model gives rise to a new Pareto Nash equilibrium concept, which we call "robust-weighted Nash equilibrium". We prove that the robust-weighted Nash equilibria are guaranteed to exist even when the weight sets are unbounded. For the worst-case weighted multi-objective game with the weight sets of players all given as polytope, we show that a robust-weighted Nash equilibrium can be obtained by solving a mathematical program with equilibrium constraints (MPEC). For an application, we illustrate the usefulness of the worst-case weighted multi-objective game to a supply chain risk management problem under demand uncertainty. By the comparison with the existed weighted approach, we show that our method is more robust and can be more efficiently used for the real-world applications.

  6. 40 CFR Appendix D to Part 112 - Determination of a Worst Case Discharge Planning Volume

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 23 2012-07-01 2012-07-01 false Determination of a Worst Case Discharge Planning Volume D Appendix D to Part 112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... determined by the RA that the facility could cause substantial harm to the environment. The calculation of a...

  7. Selection of Thermal Worst-Case Orbits via Modified Efficient Global Optimization

    NASA Technical Reports Server (NTRS)

    Moeller, Timothy M.; Wilhite, Alan W.; Liles, Kaitlin A.

    2014-01-01

    Efficient Global Optimization (EGO) was used to select orbits with worst-case hot and cold thermal environments for the Stratospheric Aerosol and Gas Experiment (SAGE) III. The SAGE III system thermal model changed substantially since the previous selection of worst-case orbits (which did not use the EGO method), so the selections were revised to ensure the worst cases are being captured. The EGO method consists of first conducting an initial set of parametric runs, generated with a space-filling Design of Experiments (DoE) method, then fitting a surrogate model to the data and searching for points of maximum Expected Improvement (EI) to conduct additional runs. The general EGO method was modified by using a multi-start optimizer to identify multiple new test points at each iteration. This modification facilitates parallel computing and decreases the burden of user interaction when the optimizer code is not integrated with the model. Thermal worst-case orbits for SAGE III were successfully identified and shown by direct comparison to be more severe than those identified in the previous selection. The EGO method is a useful tool for this application and can result in computational savings if the initial Design of Experiments (DoE) is selected appropriately.

  8. 40 CFR Appendix D to Part 112 - Determination of a Worst Case Discharge Planning Volume

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Determination of a Worst Case Discharge Planning Volume D Appendix D to Part 112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS OIL POLLUTION PREVENTION Pt. 112, App. D Appendix D to Part 112—Determination of...

  9. The Worst-Case Weighted Multi-Objective Game with an Application to Supply Chain Competitions

    PubMed Central

    Qu, Shaojian; Ji, Ying

    2016-01-01

    In this paper, we propose a worst-case weighted approach to the multi-objective n-person non-zero sum game model where each player has more than one competing objective. Our “worst-case weighted multi-objective game” model supposes that each player has a set of weights to its objectives and wishes to minimize its maximum weighted sum objectives where the maximization is with respect to the set of weights. This new model gives rise to a new Pareto Nash equilibrium concept, which we call “robust-weighted Nash equilibrium”. We prove that the robust-weighted Nash equilibria are guaranteed to exist even when the weight sets are unbounded. For the worst-case weighted multi-objective game with the weight sets of players all given as polytope, we show that a robust-weighted Nash equilibrium can be obtained by solving a mathematical program with equilibrium constraints (MPEC). For an application, we illustrate the usefulness of the worst-case weighted multi-objective game to a supply chain risk management problem under demand uncertainty. By the comparison with the existed weighted approach, we show that our method is more robust and can be more efficiently used for the real-world applications. PMID:26820512

  10. 40 CFR Appendix D to Part 112 - Determination of a Worst Case Discharge Planning Volume

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .../or operated in such a manner that the multiple tanks function as one storage unit (i.e., multiple... plan that tanks with common piping or piping systems are not operated as one unit. If such evidence is... tanks that function as one oil storage unit, the worst case discharge planning volume would be based...

  11. 40 CFR Appendix D to Part 112 - Determination of a Worst Case Discharge Planning Volume

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .../or operated in such a manner that the multiple tanks function as one storage unit (i.e., multiple... plan that tanks with common piping or piping systems are not operated as one unit. If such evidence is... tanks that function as one oil storage unit, the worst case discharge planning volume would be based...

  12. 40 CFR Appendix D to Part 112 - Determination of a Worst Case Discharge Planning Volume

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .../or operated in such a manner that the multiple tanks function as one storage unit (i.e., multiple... plan that tanks with common piping or piping systems are not operated as one unit. If such evidence is... tanks that function as one oil storage unit, the worst case discharge planning volume would be based...

  13. 30 CFR 253.14 - How do I determine the worst case oil-spill discharge volume?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I determine the worst case oil-spill... INTERIOR OFFSHORE OIL SPILL FINANCIAL RESPONSIBILITY FOR OFFSHORE FACILITIES Applicability and Amount of OSFR § 253.14 How do I determine the worst case oil-spill discharge volume? (a) To calculate the...

  14. 30 CFR 553.14 - How do I determine the worst case oil-spill discharge volume?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false How do I determine the worst case oil-spill... THE INTERIOR OFFSHORE OIL SPILL FINANCIAL RESPONSIBILITY FOR OFFSHORE FACILITIES Applicability and Amount of OSFR § 553.14 How do I determine the worst case oil-spill discharge volume? (a) To...

  15. 30 CFR 253.14 - How do I determine the worst case oil-spill discharge volume?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false How do I determine the worst case oil-spill... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL SPILL FINANCIAL RESPONSIBILITY FOR OFFSHORE FACILITIES Applicability and Amount of OSFR § 253.14 How do I determine the worst case oil-spill discharge volume? (a)...

  16. 30 CFR 553.14 - How do I determine the worst case oil-spill discharge volume?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false How do I determine the worst case oil-spill... THE INTERIOR OFFSHORE OIL SPILL FINANCIAL RESPONSIBILITY FOR OFFSHORE FACILITIES Applicability and Amount of OSFR § 553.14 How do I determine the worst case oil-spill discharge volume? (a) To...

  17. 30 CFR 553.14 - How do I determine the worst case oil-spill discharge volume?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false How do I determine the worst case oil-spill... THE INTERIOR OFFSHORE OIL SPILL FINANCIAL RESPONSIBILITY FOR OFFSHORE FACILITIES Applicability and Amount of OSFR § 553.14 How do I determine the worst case oil-spill discharge volume? (a) To...

  18. Worst case total dose radiation response of 0.35 {micro}m SOI CMOSFETs

    SciTech Connect

    Liu, S.T.; Balster, S.; Sinha, S.; Jenkins, W.C.

    1999-12-01

    Through experimental results and analysis by TSUPREM4/MEDICI simulations, the worst case back gate total dose bias condition is established for body tied SOI NMOSFETs. Utilizing the worst-case bias condition, a recently proposed model that describes the back n-channel threshold voltage shift as a function of total dose, TSUPREM4/MEDICI simulations, and circuit level SPICE simulations, a methodology to model post-rad standby current is developed and presented. This methodology requires the extraction of fundamental starting material/material preparation constants, and then can be utilized to examine post-rad stand-by current at the device and circuit level as function of total dose. Good agreement between experimental results and simulations is demonstrated.

  19. Space Environment Effects: Model for Emission of Solar Protons (ESP): Cumulative and Worst Case Event Fluences

    NASA Technical Reports Server (NTRS)

    Xapsos, M. A.; Barth, J. L.; Stassinopoulos, E. G.; Burke, E. A.; Gee, G. B.

    1999-01-01

    The effects that solar proton events have on microelectronics and solar arrays are important considerations for spacecraft in geostationary and polar orbits and for interplanetary missions. Designers of spacecraft and mission planners are required to assess the performance of microelectronic systems under a variety of conditions. A number of useful approaches exist for predicting information about solar proton event fluences and, to a lesser extent, peak fluxes. This includes the cumulative fluence over the course of a mission, the fluence of a worst-case event during a mission, the frequency distribution of event fluences, and the frequency distribution of large peak fluxes. Naval Research Laboratory (NRL) and NASA Goddard Space Flight Center, under the sponsorship of NASA's Space Environments and Effects (SEE) Program, have developed a new model for predicting cumulative solar proton fluences and worst-case solar proton events as functions of mission duration and user confidence level. This model is called the Emission of Solar Protons (ESP) model.

  20. Type-A Worst-Case Uncertainty for Gaussian noise instruments

    NASA Astrophysics Data System (ADS)

    Arpaia, P.; Baccigalupi, C.; Martino, M.

    2015-07-01

    An analytical type-A approach is proposed for predicting the Worst-Case Uncertainty of a measurement system. In a set of independent observations of the same measurand, modelled as independent- and identically-distributed random variables, the upcoming extreme values (e.g. peaks) can be forecast by only characterizing the measurement system noise level, assumed to be white and Gaussian. Simulation and experimental results are presented to validate the model for a case study on the worst-case repeatability of a pulsed power supply for the klystron modulators of the Compact LInear Collider at CERN. The experimental validation highlights satisfying results for an acquisition system repeatable in the order of ±25 ppm over a bandwidth of 5 MHz.

  1. On one-step worst-case optimal trisection in univariate bi-objective Lipschitz optimization

    NASA Astrophysics Data System (ADS)

    Žilinskas, Antanas; Gimbutienė, Gražina

    2016-06-01

    The bi-objective Lipschitz optimization with univariate objectives is considered. The concept of the tolerance of the lower Lipschitz bound over an interval is generalized to arbitrary subintervals of the search region. The one-step worst-case optimality of trisecting an interval with respect to the resulting tolerance is established. The theoretical investigation supports the previous usage of trisection in other algorithms. The trisection-based algorithm is introduced. Some numerical examples illustrating the performance of the algorithm are provided.

  2. Performance of FH/BFSK with generalized fading in worst case partial-band Gaussian interference

    NASA Astrophysics Data System (ADS)

    Crepeau, Paul J.

    1990-06-01

    For frequency-hopped (noncoherent) binary frequency shift keying (FH/BFSK) on a worst-case partial-band Gaussian interference channel, the bit error probability results are well known for the extreme cases where the signal is either nonfading or Rayleigh fading. In this work, the region between these extremes is filled in by considering the general Nakagami-m fading model. The worst-case partial-band Gaussian interference results are given by a one-parameter family which for m goes to infinity gives the Viterbi-Jacobs nonfading result, and for m = 1 gives the Rayleigh fading result. In the latter case, a broadband interference strategy is optimal. Thus, the Nakagami-m results provide a smooth one-parameter bridge between the Viterbi-Jacobs channel and the Rayleigh fading channel. The results show that the worst-case interference fraction rho increases as the fading variance increases, up to Rayleigh fading. Any fading less severe than Rayleigh, however slight the departure from Rayleigh, requires a partial-band strategy for sufficiently large Eb/NI.

  3. Sensitivity of worst-case strom surge considering influence of climate change

    NASA Astrophysics Data System (ADS)

    Takayabu, Izuru; Hibino, Kenshi; Sasaki, Hidetaka; Shiogama, Hideo; Mori, Nobuhito; Shibutani, Yoko; Takemi, Tetsuya

    2016-04-01

    There are two standpoints when assessing risk caused by climate change. One is how to prevent disaster. For this purpose, we get probabilistic information of meteorological elements, from enough number of ensemble simulations. Another one is to consider disaster mitigation. For this purpose, we have to use very high resolution sophisticated model to represent a worst case event in detail. If we could use enough computer resources to drive many ensemble runs with very high resolution model, we can handle these all themes in one time. However resources are unfortunately limited in most cases, and we have to select the resolution or the number of simulations if we design the experiment. Applying PGWD (Pseudo Global Warming Downscaling) method is one solution to analyze a worst case event in detail. Here we introduce an example to find climate change influence on the worst case storm-surge, by applying PGWD to a super typhoon Haiyan (Takayabu et al, 2015). 1 km grid WRF model could represent both the intensity and structure of a super typhoon. By adopting PGWD method, we can only estimate the influence of climate change on the development process of the Typhoon. Instead, the changes in genesis could not be estimated. Finally, we drove SU-WAT model (which includes shallow water equation model) to get the signal of storm surge height. The result indicates that the height of the storm surge increased up to 20% owing to these 150 years climate change.

  4. Multimodal object authentication with random projections: a worst-case approach

    NASA Astrophysics Data System (ADS)

    Koval, Oleksiy; Voloshynovskiy, Sviatoslav

    2010-01-01

    In this paper, we consider a forensic multimodal authentication framework based on binary hypothesis testing in random projections domain. We formulate a generic authentication problem taking into account several possible counterfeiting strategies. The authentication performance analysis is accomplished in the scope of Neyman- Pearson framework as well as for an average probability of error for both direct and random projections domains. Worst-case attack/acquisition channel leading to the worst performance loss in terms of Bhattacharyya distance reduction is presented. The obtained theoretical findings are also confirmed by results of computer simulation.

  5. Worst-Case Prediction of Single-Particle-Induced Permanent Failures in Microelectronics.

    DTIC Science & Technology

    1981-07-01

    ATTN DAMA-RAX, SYS REVIEW & PIIKHAVN NATIONAL LAIROPATORY WASHINGTON, 15’ 20101 ANALYSIS UFC ASS’AIATED, UNIVERSITIES, IN ’ ATTN DAMA- CSS -D, R&D TEAM...CHART NA A l l I i I 666of ,IANIAktl 64 A, V൴ L UNCLASSIFIED 14 ) REPORT DOCUMENTATION PAGE BFRE COSTRUTINSOR Worst-Case Prediction of Single...Washington, DC 20305 IS*. oEcL ASSI F C ATIONOWNGRAING 16. DISTRIBUTION STATEMENT (of this Report ) Approved for public release, distribution unlimited. 17

  6. Discussions On Worst-Case Test Condition For Single Event Burnout

    NASA Astrophysics Data System (ADS)

    Liu, Sandra; Zafrani, Max; Sherman, Phillip

    2011-10-01

    This paper discusses the failure characteristics of single- event burnout (SEB) on power MOSFETs based on analyzing the quasi-stationary avalanche simulation curves. The analyses show the worst-case test condition for SEB would be using the ion that has the highest mass that would result in the highest transient current due to charge deposition and displacement damage. The analyses also show it is possible to build power MOSFETs that will not exhibit SEB even when tested with the heaviest ion, which have been verified by heavy ion test data on SEB sensitive and SEB immune devices.

  7. Comparison of linear and nonlinear programming approaches for "worst case dose" and "minmax" robust optimization of intensity-modulated proton therapy dose distributions.

    PubMed

    Zaghian, Maryam; Cao, Wenhua; Liu, Wei; Kardar, Laleh; Randeniya, Sharmalee; Mohan, Radhe; Lim, Gino

    2017-03-01

    Robust optimization of intensity-modulated proton therapy (IMPT) takes uncertainties into account during spot weight optimization and leads to dose distributions that are resilient to uncertainties. Previous studies demonstrated benefits of linear programming (LP) for IMPT in terms of delivery efficiency by considerably reducing the number of spots required for the same quality of plans. However, a reduction in the number of spots may lead to loss of robustness. The purpose of this study was to evaluate and compare the performance in terms of plan quality and robustness of two robust optimization approaches using LP and nonlinear programming (NLP) models. The so-called "worst case dose" and "minmax" robust optimization approaches and conventional planning target volume (PTV)-based optimization approach were applied to designing IMPT plans for five patients: two with prostate cancer, one with skull-based cancer, and two with head and neck cancer. For each approach, both LP and NLP models were used. Thus, for each case, six sets of IMPT plans were generated and assessed: LP-PTV-based, NLP-PTV-based, LP-worst case dose, NLP-worst case dose, LP-minmax, and NLP-minmax. The four robust optimization methods behaved differently from patient to patient, and no method emerged as superior to the others in terms of nominal plan quality and robustness against uncertainties. The plans generated using LP-based robust optimization were more robust regarding patient setup and range uncertainties than were those generated using NLP-based robust optimization for the prostate cancer patients. However, the robustness of plans generated using NLP-based methods was superior for the skull-based and head and neck cancer patients. Overall, LP-based methods were suitable for the less challenging cancer cases in which all uncertainty scenarios were able to satisfy tight dose constraints, while NLP performed better in more difficult cases in which most uncertainty scenarios were hard to meet

  8. Toward the definition of a new worst-case paradigm for the preclinical evaluation of posterior spine stabilization devices.

    PubMed

    La Barbera, Luigi; Villa, Tomaso

    2017-02-01

    Mechanical reliability tests on posterior spine stabilization devices are based on standard F1717 by the American Society for Testing and Materials, which describes how to assemble the implant with vertebrae-like test blocks in a corpectomy model. A recent study proposed to revise the standard to describe the anatomical worst-case scenario, instead of the average one currently implemented, and introduce the unsupported screw length as a mechanical parameter. This article investigates the implications of such revisions on the endurance properties of an implant already on the market. Experimental fatigue tests demonstrate that the revision of F1717 standard leads to a reduction of 3.2 million cycles in the fatigue strength of the tested implant: this amount is comparable to the run-out number of cycles (5 million cycles) currently recommended. The numerical analysis, validated with static tests and strain gauges, supports the experimental findings and demonstrates that the stress on the implant may increase upon revision up to a 50% on the screw (most recurrent failure mode), with the unsupported screw length contributing alone up to 40%. The revision of ASTM F1717 standard would guarantee higher safety for the implant to test, potentially covering for a wider population of patients.

  9. Phylogenetic diversity, functional trait diversity and extinction: avoiding tipping points and worst-case losses.

    PubMed

    Faith, Daniel P

    2015-02-19

    The phylogenetic diversity measure, ('PD'), measures the relative feature diversity of different subsets of taxa from a phylogeny. At the level of feature diversity, PD supports the broad goal of biodiversity conservation to maintain living variation and option values. PD calculations at the level of lineages and features include those integrating probabilities of extinction, providing estimates of expected PD. This approach has known advantages over the evolutionarily distinct and globally endangered (EDGE) methods. Expected PD methods also have limitations. An alternative notion of expected diversity, expected functional trait diversity, relies on an alternative non-phylogenetic model and allows inferences of diversity at the level of functional traits. Expected PD also faces challenges in helping to address phylogenetic tipping points and worst-case PD losses. Expected PD may not choose conservation options that best avoid worst-case losses of long branches from the tree of life. We can expand the range of useful calculations based on expected PD, including methods for identifying phylogenetic key biodiversity areas. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  10. Worst-Case Energy Efficiency Maximization in a 5G Massive MIMO-NOMA System

    PubMed Central

    Jeong, Yongchae; Jiang, Xueqin; Lee, Moon Ho

    2017-01-01

    In this paper, we examine the robust beamforming design to tackle the energy efficiency (EE) maximization problem in a 5G massive multiple-input multiple-output (MIMO)-non-orthogonal multiple access (NOMA) downlink system with imperfect channel state information (CSI) at the base station. A novel joint user pairing and dynamic power allocation (JUPDPA) algorithm is proposed to minimize the inter user interference and also to enhance the fairness between the users. This work assumes imperfect CSI by adding uncertainties to channel matrices with worst-case model, i.e., ellipsoidal uncertainty model (EUM). A fractional non-convex optimization problem is formulated to maximize the EE subject to the transmit power constraints and the minimum rate requirement for the cell edge user. The designed problem is difficult to solve due to its nonlinear fractional objective function. We firstly employ the properties of fractional programming to transform the non-convex problem into its equivalent parametric form. Then, an efficient iterative algorithm is proposed established on the constrained concave-convex procedure (CCCP) that solves and achieves convergence to a stationary point of the above problem. Finally, Dinkelbach’s algorithm is employed to determine the maximum energy efficiency. Comprehensive numerical results illustrate that the proposed scheme attains higher worst-case energy efficiency as compared with the existing NOMA schemes and the conventional orthogonal multiple access (OMA) scheme. PMID:28927019

  11. Worst-Case Energy Efficiency Maximization in a 5G Massive MIMO-NOMA System.

    PubMed

    Chinnadurai, Sunil; Selvaprabhu, Poongundran; Jeong, Yongchae; Jiang, Xueqin; Lee, Moon Ho

    2017-09-18

    In this paper, we examine the robust beamforming design to tackle the energy efficiency (EE) maximization problem in a 5G massive multiple-input multiple-output (MIMO)-non-orthogonal multiple access (NOMA) downlink system with imperfect channel state information (CSI) at the base station. A novel joint user pairing and dynamic power allocation (JUPDPA) algorithm is proposed to minimize the inter user interference and also to enhance the fairness between the users. This work assumes imperfect CSI by adding uncertainties to channel matrices with worst-case model, i.e., ellipsoidal uncertainty model (EUM). A fractional non-convex optimization problem is formulated to maximize the EE subject to the transmit power constraints and the minimum rate requirement for the cell edge user. The designed problem is difficult to solve due to its nonlinear fractional objective function. We firstly employ the properties of fractional programming to transform the non-convex problem into its equivalent parametric form. Then, an efficient iterative algorithm is proposed established on the constrained concave-convex procedure (CCCP) that solves and achieves convergence to a stationary point of the above problem. Finally, Dinkelbach's algorithm is employed to determine the maximum energy efficiency. Comprehensive numerical results illustrate that the proposed scheme attains higher worst-case energy efficiency as compared with the existing NOMA schemes and the conventional orthogonal multiple access (OMA) scheme.

  12. Hazards assessment of worst case transportation accidents involving typical radioactive material shipments.

    PubMed

    Dodd, B; Humphries, L L

    1988-12-01

    This paper reports the results of a study performed for the Oregon Department of Energy. The objectives of the study were to characterize the range of radioactive material shipments through the state and to determine the worst radiological hazards which might arise if these shipments were involved in transportation accidents. The direct and indirect radiological hazards were analyzed for worst case accidents involving a total of 10 typical shipments. The direct hazard primarily involved the gamma radiation from the material, while the indirect hazard considered the airborne release hazards of inhalation/ingestion, cloudshine and groundshine. The general and specific assumptions used in the study are given, and the results are tabulated, giving doses and dose rates as a function of distance. The data from the study are being incorporated into a protective action guide for use by state and local emergency responders. This guide bases the protective actions on the available, observable data and on flow charts which use the worst-case assumptions for unknown data.

  13. Preliminary results and worst-case analysis of in patient scoliosis rehabilitation.

    PubMed

    Weiss, H R; Lohschmidt, K; el-Obeidi, N; Verres, C

    1997-01-01

    The purpose of this study was to assess the effectiveness of a scoliosis-specific rehabilitation programme as it is carried out in the Katharina Schroth Spinal Deformities Rehabilitation Center. Physiotherapy in the treatment of scoliosis patients is still regarded as ineffective since the study by the American Orthopedic Association in 1941, which showed that general exercises could not influence the natural history of scoliosis. However, specific exercise programmes were not known in the USA at that time. This preliminary study started in 1989 with the following inclusion criteria: (1) diagnosis of idiopathic scoliosis; (2) risser sign < 4; (3) no treatment other than physiotherapy; (4) first control after 1-3 years during repeated in patient treatment; (5) standing AP radiograph taken not more than 6 months before the first in patient treatment. A total of 181 scoliosis patients, with an average age of 12.7 years and an average angle of curvature of 27% according to Cobb, were included in this study. The average risser sign was 1.4, the average follow-up 33 months. The Cobb angle of the major curve was measured in a standardized way. The results of our preliminary study were compared to natural history as known from literature. For the worst-case analysis additionally a questionnaire was sent to the non-repeaters treated at our centre at the same time (1989 and 1990) as the patient sample described above, taking into account the same inclusion criteria for this patient sample except point 4. Results showed that progression as usually defined (increase in curvature of 5 degrees or more per year) has not been found in the preliminary study. The patient sample of this study was divided into different age groups and different groups of curve magnitude, for comparison with other studies. Additional to the patient sample of the preliminary study, 116 of the patients from the years 1989 and 1990 fulfilled the inclusion criteria of the preliminary study with the

  14. Reinforcement Learning of Optimal Supervisor based on the Worst-Case Behavior

    NASA Astrophysics Data System (ADS)

    Kajiwara, Kouji; Yamasaki, Tatsushi

    The supervisory control initiated by Ramadge and Wonham is a framework for logical control of discrete event systems. In the original supervisory control, the costs for occurrence and disabling of events have not been considered. Then, the optimal supervisory control based on quatitative measures has also been studied. This paper proposes a synthesis method of the optimal supervisor based on the worst-case behavior of discrete event systems. We introduce the new value functions for the assigned control patterns. The new value functions are not based on the expected total rewards, but based on the most undesirable event occurrence in the assigned control pattern. In the proposed method, the supervisor learns how to assign the control pattern based on reinforcement learning so as to maximize the value functions. We show the efficiency of the proposed method by computer simulation.

  15. A Worst-Case Approach for On-Line Flutter Prediction

    NASA Technical Reports Server (NTRS)

    Lind, Rick C.; Brenner, Martin J.

    1998-01-01

    Worst-case flutter margins may be computed for a linear model with respect to a set of uncertainty operators using the structured singular value. This paper considers an on-line implementation to compute these robust margins in a flight test program. Uncertainty descriptions are updated at test points to account for unmodeled time-varying dynamics of the airplane by ensuring the robust model is not invalidated by measured flight data. Robust margins computed with respect to this uncertainty remain conservative to the changing dynamics throughout the flight. A simulation clearly demonstrates this method can improve the efficiency of flight testing by accurately predicting the flutter margin to improve safety while reducing the necessary flight time.

  16. Modelling the long-term evolution of worst-case Arctic oil spills.

    PubMed

    Blanken, Hauke; Tremblay, Louis Bruno; Gaskin, Susan; Slavin, Alexander

    2017-03-15

    We present worst-case assessments of contamination in sea ice and surface waters resulting from hypothetical well blowout oil spills at ten sites in the Arctic Ocean basin. Spill extents are estimated by considering Eulerian passive tracers in the surface ocean of the MITgcm (a hydrostatic, coupled ice-ocean model). Oil in sea ice, and contamination resulting from melting of oiled ice, is tracked using an offline Lagrangian scheme. Spills are initialized on November 1st 1980-2010 and tracked for one year. An average spill was transported 1100km and potentially affected 1.1 million km(2). The direction and magnitude of simulated oil trajectories are consistent with known large-scale current and sea ice circulation patterns, and trajectories frequently cross international boundaries. The simulated trajectories of oil in sea ice match observed ice drift trajectories well. During the winter oil transport by drifting sea ice is more significant than transport with surface currents.

  17. Strategies for FH/MFSK signaling with diversity in worst-case partial-band noise

    NASA Technical Reports Server (NTRS)

    Levitt, B. K.

    1985-01-01

    Optimum diversity and worst-case partial-band noise jamming conditions have been derived for noncoherent energy detection of frequency-hopped (FH) M-ary frequency-shift keyed (MFSK) signals using a soft-chip decision suboptimum linear combining metric with perfect jamming-state side information. However, the assumption implicit in previous publications is that the error is first maximized over the jammer's partial-band duty factor for arbitrary diversity, and the result is then minimized over the amount of diversity. This paper shows that if the order of optimization is reversed, different conditions and performance are produced; that is, the previous solution is not a saddlepoint. This introduces some game-theoretic considerations for the communicator and the jammer, the risks and advantages of which are explored.

  18. Determining worst-case fatigue thresholds for grain-bridging ceramics

    SciTech Connect

    Kruzic, J.J.; Yuan, R.; Canon, R.M.; Ritchie, R.O.

    2002-10-07

    A method for determining worst-case cyclic fatigue thresholds in grain-bridging ceramics by quantifying the role of bridging is demonstrated for a model alumina. Crack-growth properties for both long and short (< 2 mm) cracks emanating from machined notches (root radii, (rho) {approx}; 15 - 150 (mu)m) were investigated. When compared as a function of the applied stress-intensity range (delta K), growth rates (da/dN) were far higher and fatigue thresholds (Delta)KTH were markedly lower with short cracks, with growth being observable at the lowest driving forces for short cracks emanating from razor micronotches ((rho)is approximately equal to 15 (mu)m). For growth rates < 10-8 m/cycle, da/dN vs. (delta)K data for short cracks merged with the steady-state data for long cracks after {approx}2 mm of extension.

  19. Worst-Case" Simulant for INTEC Soduim-Bearing Waste Vitrification Tests

    SciTech Connect

    Christian, Jerry Dale; Batcheller, Thomas Aquinas

    2001-09-01

    The Idaho Nuclear Technology and Engineering Center (INTEC) is developing technologies to process the radioactive liquid sodium-bearing waste from the waste tanks at INTEC to solidify the waste into a form suitable for disposition in a National high-level waste repository currently being considered at Yucca Mountain, Nevada. The requirement is for a qualified glass waste form. Therefore, vitrification is being developed using laboratory, research-scale, and pilot scale melters. While some laboratory experiments can be done with actual waste, the larger scale and most laboratory experiments must be done on non-radioactive simulant waste solutions. Some tests have previously been done on simulants of a representative waste that has been concentrated and will remain unchanged in tank WM-180 until it is vitrified. However, there is a need to develop glass compositions that will accommodate all future wastes in the tanks. Estimates of those future waste compositions have been used along with current compositions to develop a “worst-case” waste composition and a simulant preparation recipe suitable for developing a bracketing glass formulation and for characterizing the flowpath and decontamination factors of pertinent off-gas constituents in the vitrification process. The considerations include development of criteria for a worst-case composition. In developing the criteria, the species that are known to affect vitrification and glass properties were considered. Specific components that may need to be characterized in the off-gas cleanup system were considered in relation to detection limits that would need to be exceeded in order to track those components. Chemical aspects of various constituent interactions that should be taken into account when a component may need to be increased in concentration from that in the actual waste for detection in experiments were evaluated. The worst-case waste simulant composition is comprised of the highest concentration of each

  20. Atmospheric dispersion modeling for the worst-case detonation accident at the proposed Advanced Hydrotest Facility

    SciTech Connect

    Bowen, B.M., LLNL

    1996-10-01

    The Atmospheric Release Advisory Capability (ARAC) was requested to estimate credible worst-case dose, air concentration, and deposition of airborne hazardous materials that would result from a worst-case detonation accident at the proposed Advanced Hydrotest Facility (AHT) at the Nevada Test Site (NTS). Consequences were estimated at the closest onsite facility, the Device Assembly Facility (DOFF), and offsite location (intersection of Highway and U.S. 95). The materials considered in this analysis were weapon-grade plutonium, beryllium, and hydrogen fluoride which is a combustion product whose concentration is dependent upon the quantity of high explosives. The analysis compares the calculated results with action guidelines published by the Department of Defense in DoD 5100.52-M (Nuclear Weapon Accident Response Procedures). Results indicate that based on a one kg release of plutonium the whole body radiation dose could be as high as 3 Rem at the DOFF. This level approaches the 5 Rem level for which the Department of Defense requires respiratory protection, recommends sheltering and the consideration of evacuation. Deposition levels at the DOFF could approach 6 uCi/m{sup 2} for which the Department of Defense recommends access on a need-only basis and suggests that a possible controlled evacuation might be required. For a one kg release of plutonium, the dose at the nearest off-site location could reach 0.5. At this level, the Department of Defense suggests that sheltering be considered. For a one kg release of beryllium, the peak 5-minute concentration at the DOFF could be as as 20% of 6xlO{sup -3} mg/m{sup 2} which is the applicable by Response Planning Guideline (ERPG-1). At the nearest offsite location, the beryllium concentrations from a one kg release would be two orders of magnitude less than the same guideline. For the detonation of 100 kg of the explosive LX-17, the concentration of hydrogen fluoride at both the DOFF and the nearest offsite location

  1. Zero-moment point determination of worst-case manoeuvres leading to vehicle wheel lift

    NASA Astrophysics Data System (ADS)

    Lapapong, S.; Brown, A. A.; Swanson, K. S.; Brennan, S. N.

    2012-01-01

    This paper proposes a method to evaluate vehicle rollover propensity based on a frequency-domain representation of the zero-moment point (ZMP). Unlike other rollover metrics such as the static stability factor, which is based on the steady-state behaviour, and the load transfer ratio, which requires the calculation of tyre forces, the ZMP is based on a simplified kinematic model of the vehicle and the analysis of the contact point of the vehicle relative to the edge of the support polygon. Previous work has validated the use of the ZMP experimentally in its ability to predict wheel lift in the time domain. This work explores the use of the ZMP in the frequency domain to allow a chassis designer to understand how operating conditions and vehicle parameters affect rollover propensity. The ZMP analysis is then extended to calculate worst-case sinusoidal manoeuvres that lead to untripped wheel lift, and the analysis is tested across several vehicle configurations and compared with that of the standard Toyota J manoeuvre.

  2. Incremental Multi-Scale Search Algorithm for Dynamic Path Planning With Low Worst-Case Complexity.

    PubMed

    Yibiao Lu; Xiaoming Huo; Arslan, O; Tsiotras, P

    2011-12-01

    Path-planning (equivalently, path-finding) problems are fundamental in many applications, such as transportation, VLSI design, robot navigation, and many more. In this paper, we consider dynamic shortest path-planning problems on a graph with a single endpoint pair and with potentially changing edge weights over time. Several algorithms exist in the literature that solve this problem, notably among them the Lifelong Planning algorithm. The algorithm is an incremental search algorithm that replans the path when there are changes in the environment. In numerical experiments, however, it was observed that the performance of is sensitive in the number of vertex expansions required to update the graph when an edge weight value changes or when a vertex is added or deleted. Although, in most cases, the classical requires a relatively small number of updates, in some other cases the amount of work required by the to find the optimal path can be overwhelming. To address this issue, in this paper, we propose an extension of the baseline algorithm, by making efficient use of a multiscale representation of the environment. This multiscale representation allows one to quickly localize the changed edges, and subsequently update the priority queue efficiently. This incremental multiscale ( for short) algorithm leads to an improvement both in terms of robustness and computational complexity-in the worst case-when compared to the classical . Numerical experiments validate the aforementioned claims.

  3. Comparison of temporal realistic telecommunication base station exposure with worst-case estimation in two countries.

    PubMed

    Mahfouz, Zaher; Verloock, Leen; Joseph, Wout; Tanghe, Emmeric; Gati, Azeddine; Wiart, Joe; Lautru, David; Hanna, Victor Fouad; Martens, Luc

    2013-12-01

    The influence of temporal daily exposure to global system for mobile communications (GSM) and universal mobile telecommunications systems and high speed downlink packet access (UMTS-HSDPA) is investigated using spectrum analyser measurements in two countries, France and Belgium. Temporal variations and traffic distributions are investigated. Three different methods to estimate maximal electric-field exposure are compared. The maximal realistic (99 %) and the maximal theoretical extrapolation factor used to extrapolate the measured broadcast control channel (BCCH) for GSM and the common pilot channel (CPICH) for UMTS are presented and compared for the first time in the two countries. Similar conclusions are found in the two countries for both urban and rural areas: worst-case exposure assessment overestimates realistic maximal exposure up to 5.7 dB for the considered example. In France, the values are the highest, because of the higher population density. The results for the maximal realistic extrapolation factor at the weekdays are similar to those from weekend days.

  4. Worst case earth charging environment. [geosynchronous plasma environment in sunlight for predicting spacecraft potential in eclipse

    NASA Technical Reports Server (NTRS)

    Deutsch, M.-J. C.

    1982-01-01

    The Applications Technology Satellite-6 (ATS-6) geosynchronous satellite charged up to -2200 V in sunlight on day 178, 1974. This event, being the highest known spacecraft charging event in sunlight, is used to estimate a worst case geosynchronous plasma environment for predicting the spacecraft potential in eclipse. The advantage of using this sunlight spectrum as opposed to an eclipse case is that the ion and electron fluxes to the detectors are shifted only slightly due to the spacecraft potential. After correcting the available data for satellite potential and missing data above 81 KeV, it is found that the plasma can be characterized by a single Maxwellian approximation having an electron density of 1.22/cu cm, electron temperature of 16 KeV, hydrogen ion density of 0.24/cu cm, and hydrogen ion temperature of 29 KeV. In eclipse the spacecraft would have charged up to -28 kV, the highest estimated potential to date in the earth's plasma environment.

  5. The determination of risk areas for muddy floods based on a worst-case erosion modelling

    NASA Astrophysics Data System (ADS)

    Saathoff, Ulfert; Schindewolf, Marcus; Annika Arévalo, Sarah

    2013-04-01

    Soil erosion and muddy floods are a frequently occurring hazard in the German state of Saxony, because of the topography and the high relief energy together with the high proportion of arable land. Still, the events are rather heterogeneously distributed and we do not know where damage is likely to occur. The goal of this study is to locate hot spots for the risk of muddy floods, with the objective to prevent high economic damage in future. We applied a soil erosion and deposition map of Saxony, calculated with the process based soil erosion model EROSION 3D. This map shows the potential soil erosion and transported sediment for worst case soil conditions and a 10 year rain storm event. Furthermore, a map of the current landuse in the state is used. From the landuse map, we extracted those areas that are especially vulnerable to muddy floods, like residential and industrial areas, infrastructural facilities (e.g. power plants, hospitals) and highways. In combination with the output of the soil erosion model, the amount of sediment, that enters each single landuse entity, is calculated. Based on this data, a state-wide map with classified risks is created. The results are furthermore used to identify the risk of muddy floods for each single municipality in Saxony. The results are evaluated with data of real occurred muddy flood events with documented locations during the period between 2000 and 2010. Additionally, plausibility tests are performed for selected areas (examination of landuse, topography and soil). The results prove to be plausible and most of the documented events can be explained by the modelled risk map. The created map can be used by different institutions like city and traffic planners, to estimate the risk of muddy flood occurrence at specific locations. Furthermore, the risk map can serve insurance companies to evaluate the insurance risk of a building. To make them easily accessible, the risk map will be published online via a web GIS

  6. SU-E-T-642: PTV Is the Voxel-Wise Worst-Case of CTV in Prostate Photon Therapy

    SciTech Connect

    Harrington, D; Schild, S; Wong, W; Vora, S; Liu, W

    2015-06-15

    Purpose: To examine the adequacy of the planning target volume (PTV) dose distribution as the worst-case representation of clinical target volume (CTV) dose distribution in prostate volumetric-modulated arc therapy (VMAT) plans. Methods: Ten intact prostate cancer cases treated by VMAT at our institution were randomly selected. Isocenter was shifted in the three cardinal directions by a displacement equal to the PTV expansion on the CTV (±3 mm) for a total of six shifted plans per original plan. Rotationally-perturbed plans were generated with a couch rotation of ±1° to simulate patient yaw. The eight perturbed dose distributions were recalculated in the treatment planning system using the same, fixed fluence map as the original plan. The voxel-wise worst-case CTV dose distribution was constructed from the minimum value per voxel from the eight perturbed doses. The resulting dose volume histograms (DVH) were evaluated for statistical correlation between the worst-case CTV and nominal PTV dose distributions based on D95% by Wilcoxon signed-rank test with significance level p ≤ 0.05. Results: Inspection demonstrates the PTV DVH in the nominal dose distribution is bounded by the CTV DVH in the worst-case dose distribution. Comparison of D95% for the two dose distributions by Wilcoxon signed-rank test gives p = 0.131. Therefore the null hypothesis cannot be rejected since the difference in median values is not statistically significant. Conclusion: The assumption that the nominal dose distribution for PTV represents the worst-case dose distribution for CTV appears valid for the ten plans under examination. Although the worst-case dose distribution is unphysical since the dose per voxel is chosen independently, it serves as a lower bound for the possible CTV coverage. Furthermore, this is consistent with the unphysical nature of the PTV. Minor discrepancies between the two dose distributions are expected since the dose cloud is not strictly static. Funding Support

  7. Accuracy of the cosmic-ray soil water content probe in humid forest ecosystems: The worst case scenario

    NASA Astrophysics Data System (ADS)

    Bogena, H. R.; Huisman, J. A.; Baatz, R.; Hendricks Franssen, H.-J.; Vereecken, H.

    2013-09-01

    Soil water content is one of the key state variables in the soil-vegetation-atmosphere continuum due to its important role in the exchange of water and energy at the soil surface. A new promising method to measure integral soil water content at the field or small catchment scale is the cosmic-ray probe (CRP). Recent studies of CRP measurements have mainly presented results from test sites located in very dry areas and from agricultural fields with sandy soils. In this study, distributed continuous soil water content measurements from a wireless sensor network (SoilNet) were used to investigate the accuracy of CRP measurements for soil water content determination in a humid forest ecosystem. Such ecosystems are less favorable for CRP applications due to the presence of a litter layer. In addition, lattice water and carbohydrates of soil organic matter and belowground biomass reduce the effective sensor depth and thus were accounted for in the calibration of the CRP. The hydrogen located in the biomass decreased the level of neutron count rates and thus also decreased the sensitivity of the cosmic-ray probe, which in turn resulted in an increase of the measurement uncertainty. This uncertainty was compensated by using longer integration times (e.g., 24 h). For the Wüstebach forest site, the cosmic-ray probe enabled the assessment of integral daily soil water content dynamics with a RMSE of about 0.03 cm3/cm3 without explicitly considering the litter layer. By including simulated water contents of the litter layer in the calibration, a better accuracy could be achieved.

  8. The MacArthur Maze Fire and Roadway Collapse: A "Worst Case Scenario" for Spent Nuclear Fuel Transportation?

    SciTech Connect

    Bajwa, Christopher S.; Easton, Earl P.; Adkins, Harold E.; Cuta, Judith M.; Klymyshyn, Nicholas A.; Suffield, Sarah R.

    2012-07-06

    In 2007, a severe transportation accident occurred near Oakland, California, at the interchange known as the "MacArthur Maze." The accident involved a double tanker truck of gasoline overturning and bursting into flames. The subsequent fire reduced the strength of the supporting steel structure of an overhead interstate roadway causing the collapse of portions of that overpass onto the lower roadway in less than 20 minutes. The US Nuclear Regulatory Commission has analyzed what might have happened had a spent nuclear fuel transportation package been involved in this accident, to determine if there are any potential regulatory implications of this accident to the safe transport of spent nuclear fuel in the United States. This paper provides a summary of this effort, presents preliminary results and conclusions, and discusses future work related to the NRC's analysis of the consequences of this type of severe accident.

  9. Preparing for the Worst-Case Scenario--Planning Pays Off with First-Ever Stadium Evacuation

    ERIC Educational Resources Information Center

    Bradley, Carol C.

    2012-01-01

    It's Saturday, September 3, Notre Dame vs. South Florida--the first home game of the season--and nearing halftime. The only person feeling more pressure than Head Coach Brian Kelly is Mike Seamon, associate vice president for campus safety and director of game day operations. Bad weather is on the way, and he's about to make the call to evacuate…

  10. Impacts of fertilizer additions on water quality of a drained pine plantation in North Carolina. A worst case scenario.

    Treesearch

    Bray J. Beltran; Devendra M. Amatya; Martin Jones; R. Wayne Skaggs; William Neal Reynolds; Timothy J. Callahan; Jami E. Nettles

    2008-01-01

    Abstract. Intensive plantation forestry will be increasingly important in the next 50 years to meet the high demand for domestic wood in the US. However, forestry management practices can substantially influence downstream water quality and ecology. In this study, the effect of fertilization on drainage water quality of a coastal pine plantation located in Carteret...

  11. Impacts of fertilizer additions on water quality of a drained pine plantation in North Carolina. A worst case scenario.

    Treesearch

    Bray J. Beltran; Devendra M. Amatya; Martin Jones; R. Wayne Skaggs; William Neal P.E. Reynolds; Timothy J. Callahan; Jami E. Nettles

    2008-01-01

    Intensive plantation forestry will be increasingly important in the next 50 years to meet the high demand for domestic wood in the US. However, forestry management practices can substantially influence downstream water quality and ecology. In this study, the effect of fertilization on drainage water quality of a coastal pine plantation located in Carteret County, NC...

  12. Worst-Case Cooperative Jamming for Secure Communications in CIoT Networks.

    PubMed

    Li, Zhen; Jing, Tao; Ma, Liran; Huo, Yan; Qian, Jin

    2016-03-07

    The Internet of Things (IoT) is a significant branch of the ongoing advances in the Internet and mobile communications. The use of a large number of IoT devices makes the spectrum scarcity problem even more serious. The usable spectrum resources are almost entirely occupied, and thus, the increasing radio access demands of IoT devices cannot be met. To tackle this problem, the Cognitive Internet of Things (CIoT) has been proposed. In a CIoT network, secondary users, i.e., sensors and actuators, can access the licensed spectrum bands provided by licensed primary users (such as telephones). Security is a major concern in CIoT networks. However, the traditional encryption method at upper layers (such as symmetric cryptography and asymmetric cryptography) may be compromised in CIoT networks, since these types of networks are heterogeneous. In this paper, we address the security issue in spectrum-leasing-based CIoT networks using physical layer methods. Considering that the CIoT networks are cooperative networks, we propose to employ cooperative jamming to achieve secrecy transmission. In the cooperative jamming scheme, a certain secondary user is employed as the helper to harvest energy transmitted by the source and then uses the harvested energy to generate an artificial noise that jams the eavesdropper without interfering with the legitimate receivers. The goal is to minimize the signal to interference plus noise ratio (SINR) at the eavesdropper subject to the quality of service (QoS) constraints of the primary traffic and the secondary traffic. We formulate the considered minimization problem into a two-stage robust optimization problem based on the worst-case Channel State Information of the Eavesdropper. By using semi-definite programming (SDP), the optimal solutions of the transmit covariance matrices can be obtained. Moreover, in order to build an incentive mechanism for the secondary users, we propose an auction framework based on the cooperative jamming scheme

  13. Worst-Case Cooperative Jamming for Secure Communications in CIoT Networks

    PubMed Central

    Li, Zhen; Jing, Tao; Ma, Liran; Huo, Yan; Qian, Jin

    2016-01-01

    The Internet of Things (IoT) is a significant branch of the ongoing advances in the Internet and mobile communications. Yet, the use of a large number of IoT devices can severely worsen the spectrum scarcity problem. The usable spectrum resources are almost entirely occupied, and thus, the increasing demands of radio access from IoT devices cannot be met. To tackle this problem, the Cognitive Internet of Things (CIoT) has been proposed. In a CIoT network, secondary users, i.e., sensors and actuators, can access the licensed spectrum bands provided by licensed primary users (such as cellular telephones). Security is a major concern in CIoT networks. However, the traditional encryption method at upper layers (such as symmetric and asymmetric ciphers) may not be suitable for CIoT networks since these networks are composed of low-profile devices. In this paper, we address the security issues in spectrum-leasing-based CIoT networks using physical layer methods. Considering that the CIoT networks are cooperative in nature, we propose to employ cooperative jamming to achieve secure transmission. In our proposed cooperative jamming scheme, a certain secondary user is employed as the helper to harvest energy transmitted by the source and then uses the harvested energy to generate an artificial noise that jams the eavesdropper without interfering with the legitimate receivers. The goal is to minimize the Signal to Interference plus Noise Ratio (SINR) at the eavesdropper subject to the Quality of Service (QoS) constraints of the primary traffic and the secondary traffic. We formulate the minimization problem into a two-stage robust optimization problem based on the worst-case Channel State Information of the Eavesdropper (ECSI). By using Semi-Definite Programming (SDP), the optimal solutions of the transmit covariance matrices can be obtained. Moreover, in order to build an incentive mechanism for the secondary users, we propose an auction framework based on the cooperative

  14. Space Environment Effects: Model for Emission of Solar Protons (ESP)--Cumulative and Worst-Case Event Fluences

    NASA Technical Reports Server (NTRS)

    Xapsos, M. A.; Barth, J. L.; Stassinopoulos, E. G.; Burke, Edward A.; Gee, G. B.

    1999-01-01

    The effects that solar proton events have on microelectronics and solar arrays are important considerations for spacecraft in geostationary and polar orbits and for interplanetary missions. Designers of spacecraft and mission planners are required to assess the performance of microelectronic systems under a variety of conditions. A number of useful approaches exist for predicting information about solar proton event fluences and, to a lesser extent, peak fluxes. This includes the cumulative fluence over the course of a mission, the fluence of a worst-case event during a mission, the frequency distribution of event fluences, and the frequency distribution of large peak fluxes. Naval Research Laboratory (NRL) and NASA Goddard Space Flight Center, under the sponsorship of NASA's Space Environments and Effects (SEE) Program, have developed a new model for predicting cumulative solar proton fluences and worst-case solar proton events as functions of mission duration and user confidence level. This model is called the Emission of Solar Protons (ESP) model.

  15. Interplanetary crew dose estimates for worst case solar particle events based on historical data for the Carrington flare of 1859.

    PubMed

    Stephens, Daniel L; Townsend, Lawrence W; Hoff, Jennifer L

    2005-01-01

    Over the past two decades, hypothetical models of "worst-case" solar particle event (SPE) spectra have been proposed in order to place an upper bound on radiation doses to critical body organs of interplanetary crews on deep space missions. These event spectra are usually formulated using hypothetical extrapolations of space measurements for previous large events. Here we take a different approach. Recently reported analyses of ice core samples indicate that the Carrington flare of 1859 is the largest event observed in the past 500 years. These ice core data yield estimates of the proton fluence for energies greater than 30 MeV, but provide no other spectrum information. Assuming that the proton energy distribution for such an event is similar to that measured for other recent, large events, interplanetary crew doses are estimated for these hypothetical worst case SPE spectra. These estimated doses are life threatening unless substantial shielding is provided. c2005 Elsevier Ltd. All rights reserved.

  16. Chebyshev-polynomial-based (CPB) unified model neural network for the worst-case identification of nonlinear systems H∞ problem

    NASA Astrophysics Data System (ADS)

    Jeng, Jin-Tsong; Lee, Tsu-Tian

    1998-03-01

    In this paper, we propose a neural network model with a faster learning speed and a good approximate capability in the function approximation for solving worst-case identification of nonlinear systems H(infinity ) problems. Specifically, via the approximate transformable technique, we develop a Chebyshev Polynomials Based unified model neural network for solving the worst-case identification of nonlinear systems H(infinity ) problems. Based on this approximate transformable technique, the relationship between the single-layered neural network and multi-layered perceptron neural network is derived. It is shown that the Chebyshev Polynomials Based unified model neural network can be represented as a functional link network that is based on Chebyshev polynomials. We also derive a new learning algorithm such that the infinity norm of the transfer function from the input to the output is under a prescribed level. It turns out that the Chebyshev Polynomials Based unified model neural network not only has the same capability of universal approximator, but also has a faster learning speed than multi-layered perceptron or the recurrent neural network in the deterministic worst-case identification of nonlinear systems H(infinity ) problems.

  17. A Framework to Improve Surgeon Communication in High-Stakes Surgical Decisions: Best Case/Worst Case.

    PubMed

    Taylor, Lauren J; Nabozny, Michael J; Steffens, Nicole M; Tucholka, Jennifer L; Brasel, Karen J; Johnson, Sara K; Zelenski, Amy; Rathouz, Paul J; Zhao, Qianqian; Kwekkeboom, Kristine L; Campbell, Toby C; Schwarze, Margaret L

    2017-06-01

    Although many older adults prefer to avoid burdensome interventions with limited ability to preserve their functional status, aggressive treatments, including surgery, are common near the end of life. Shared decision making is critical to achieve value-concordant treatment decisions and minimize unwanted care. However, communication in the acute inpatient setting is challenging. To evaluate the proof of concept of an intervention to teach surgeons to use the Best Case/Worst Case framework as a strategy to change surgeon communication and promote shared decision making during high-stakes surgical decisions. Our prospective pre-post study was conducted from June 2014 to August 2015, and data were analyzed using a mixed methods approach. The data were drawn from decision-making conversations between 32 older inpatients with an acute nonemergent surgical problem, 30 family members, and 25 surgeons at 1 tertiary care hospital in Madison, Wisconsin. A 2-hour training session to teach each study-enrolled surgeon to use the Best Case/Worst Case communication framework. We scored conversation transcripts using OPTION 5, an observer measure of shared decision making, and used qualitative content analysis to characterize patterns in conversation structure, description of outcomes, and deliberation over treatment alternatives. The study participants were patients aged 68 to 95 years (n = 32), 44% of whom had 5 or more comorbid conditions; family members of patients (n = 30); and surgeons (n = 17). The median OPTION 5 score improved from 41 preintervention (interquartile range, 26-66) to 74 after Best Case/Worst Case training (interquartile range, 60-81). Before training, surgeons described the patient's problem in conjunction with an operative solution, directed deliberation over options, listed discrete procedural risks, and did not integrate preferences into a treatment recommendation. After training, surgeons using Best Case/Worst Case clearly presented a choice between

  18. A Framework to Improve Surgeon Communication in High-Stakes Surgical Decisions: Best Case/Worst Case

    PubMed Central

    Taylor, Lauren J; Nabozny, Michael J; Steffens, Nicole M; Tucholka, Jennifer L; Brasel, Karen J; Johnson, Sara K; Zelenski, Amy; Rathouz, Paul J.; Zhao, Qianqian; Kwekkeboom, Kristine L; Campbell, Toby C; Schwarze, Margaret L

    2017-01-01

    Importance Although many older adults prefer to avoid burdensome interventions with limited ability to preserve their functional status, aggressive treatments, including surgery, are common near the end of life. Shared decision making is critical to achieve value-concordant treatment decisions and minimize unwanted care. However, communication in the acute inpatient setting is challenging. Objective To evaluate the proof of concept of an intervention to teach surgeons to use the Best Case/Worst Case framework as a strategy to change surgeon communication and promote shared decision making during high-stakes surgical decisions. Design, Setting, and Participants Our prospective pre-post study was conducted from June 2014 to August 2015 and data were analyzed using a mixed methods approach. The data were drawn from decision-making conversations between 32 older inpatients with an acute nonemergent surgical problem, 30 family members, and 25 surgeons at 1 tertiary care hospital in Madison, Wisconsin. Intervention A 2-hour training session to teach each study-enrolled surgeon to use the Best Case/Worst Case communication framework. Main Outcome and Measures We scored conversation transcripts using OPTION 5, an observer measure of shared decision making, and used qualitative content analysis to characterize patterns in conversation structure, description of outcomes and deliberation over treatment alternatives. Results The study participants were patients aged 68 to 95 years (n=32), 44% of whom had 5 or more comorbid conditions; family members of patients (n=30); and surgeons (n=17). The median OPTION 5 score improved from 41 pre-intervention (interquartile range 26–66) to 74 after Best Case/Worst Case training (interquartile range 60–81). Before training, surgeons described the patient’s problem in conjunction with an operative solution, directed deliberation over options, listed discrete procedural risks and did not integrate preferences into a treatment

  19. Control-oriented modelization of a satellite with large flexible appendages and use of worst-case analysis to verify robustness to model uncertainties of attitude control

    NASA Astrophysics Data System (ADS)

    Gasbarri, Paolo; Monti, Riccardo; Campolo, Giovanni; Toglia, Chiara

    2012-12-01

    lengthy and expensive: difficulty and cost do increase because of the overall system dimension that depends on the number of uncertainties. Uncertain parameters have to be parametrically investigated to determine robust performance of the control laws via gridding approaches. In particular in this paper we propose to consider two methods: (i) a conventional Monte Carlo analysis, and (ii) a worst-case analysis, i.e., an optimization process to find an estimation of the true worst-case behaviour. Both techniques allow to verify that the design is robust enough to meet the system performance specification in case of uncertainties.

  20. A characterization of robust radiation therapy treatment planning methods-from expected value to worst case optimization

    SciTech Connect

    Fredriksson, Albin

    2012-08-15

    Purpose: To characterize a class of optimization formulations used to handle systematic and random errors in radiation therapy, and to study the differences between the methods within this class. Methods: The class of robust methods that can be formulated as minimax stochastic programs is studied. This class generalizes many previously used methods, ranging between optimization of the expected and the worst case objective value. The robust methods are used to plan intensity-modulated proton therapy (IMPT) treatments for a case subject to systematic setup and range errors, random setup errors with and without uncertain probability distribution, and combinations thereof. As reference, plans resulting from a conventional method that uses a margin to account for errors are shown. Results: For all types of errors, target coverage robustness increased with the conservativeness of the method. For systematic errors, best case organ at risk (OAR) doses increased and worst case doses decreased with the conservativeness. Accounting for random errors of fixed probability distribution resulted in heterogeneous dose. The heterogeneities were reduced when uncertainty in the probability distribution was accounted for. Doing so, the OAR doses decreased with the conservativeness. All robust methods studied resulted in more robust target coverage and lower OAR doses than the conventional method. Conclusions: Accounting for uncertainties is essential to ensure plan quality in complex radiation therapy such as IMPT. The utilization of more information than conventional in the optimization can lead to robust target coverage and low OAR doses. Increased target coverage robustness can be achieved by more conservative methods.

  1. Prediction of worst case concentrations due to landfill emissions in absence of historical emissions in absence of historical meteorological data

    SciTech Connect

    Kura, B.; Lea, W.R.

    1995-08-01

    Planning for a new landfill site in a given locality requires a detailed environmental impact analysis to evaluate qualitative and quantitative impacts on the surrounding environment. Among several environmental parameters of interest, air quality is of the utmost concern due to landfill gas emissions. Methane and carbon dioxide are the two principal gases in the landfill gas with small percentage of ammonia, and other VOC gases. This paper presents a methodology for estimating the worst case methane concentrations assuming sample meteorological conditions. As an example, a municipal solid waste (MSW) landfill of size 100 m x 100 m was considered with different fill heights (10 m, 50 m and 100 m). The isopleths (lines of equal concentration) for methane are plotted using the dispersion model. Also, the curves for methane concentration versus downwind distance are provided for various fill heights.

  2. Probabilistic risk assessment for the Los Alamos Meson Physics Facility worst-case design-basis accident

    SciTech Connect

    Sharirli, M.; Butner, J.M.; Rand, J.L.; Macek, R.J. ); McKinney, S.J. ); Roush, M.L. . Center for Reliability Engineering)

    1992-01-01

    This paper presents results from a Los Alamos National Laboratory Engineering and Safety Analysis Group assessment of the worse-case design-basis accident associated with the Clinton P. Anderson Meson Physics Facility (LAMPF)/Weapons Neutron Research (WNR) Facility. The primary goal of the analysis was to quantify the accident sequences that result in personnel radiation exposure in the WNR Experimental Hall following the worst-case design-basis accident, a complete spill of the LAMPF accelerator 1L beam. This study also provides information regarding the roles of hardware systems and operators in these sequences, and insights regarding the areas where improvements can increase facility-operation safety. Results also include confidence ranges to incorporate combined effects of uncertainties in probability estimates and importance measures to determine how variations in individual events affect the frequencies in accident sequences.

  3. Probabilistic risk assessment for the Los Alamos Meson Physics Facility worst-case design-basis accident

    SciTech Connect

    Sharirli, M.; Butner, J.M.; Rand, J.L.; Macek, R.J.; McKinney, S.J.; Roush, M.L.

    1992-12-01

    This paper presents results from a Los Alamos National Laboratory Engineering and Safety Analysis Group assessment of the worse-case design-basis accident associated with the Clinton P. Anderson Meson Physics Facility (LAMPF)/Weapons Neutron Research (WNR) Facility. The primary goal of the analysis was to quantify the accident sequences that result in personnel radiation exposure in the WNR Experimental Hall following the worst-case design-basis accident, a complete spill of the LAMPF accelerator 1L beam. This study also provides information regarding the roles of hardware systems and operators in these sequences, and insights regarding the areas where improvements can increase facility-operation safety. Results also include confidence ranges to incorporate combined effects of uncertainties in probability estimates and importance measures to determine how variations in individual events affect the frequencies in accident sequences.

  4. Conscious worst case definition for risk assessment, part II: a methodological case study for pesticide risk assessment.

    PubMed

    Sørensen, Peter B; Giralt, Francesc; Rallo, Robert; Espinosa, Gabriela; Münier, Bernd; Gyldenkaerne, Steen; Thomsen, Marianne

    2010-08-15

    This paper illustrates, by a case study, how to apply the conceptual Worst-Case Definition (WCD) model, developed in the methodological paper in the current journal, by Sørensen et al. (2010-this issue). The case is about eco-toxicological risk assessment of pesticides under Danish conditions. Cumulative aspects are included on a conceptual basis as elements of the worst-case conditions. This defines factors that govern the risk assessment, including location in time and space of risk "hotspots". Two pillars of concern drive the conceptual modelling: (1) What to protect (denoted Protected Units (PUs)) and (2) the reason for increased risk level (denoted Causes of Risks (CRs)). Both PUs and CRs are analysed using hierarchical procedures that facilitate a complete listing of concrete factors governing increased risk for adverse effect due to agricultural usage of pesticide. The factors governing pesticide risk are combined in a context that combines the protection of relevant groupings of organisms with the factors for increased risk level for each of these. Identification of the most important relations between defined types of PUs and CRs is illustrated using expert knowledge. Existing databases are used to form spatial distributed risk indicators as estimators for a selection of important relations between PUs and CRs. This paper illustrates how the WCD model can break down the complex issue of uncertainty into fractions that are more open for evaluations. Finally, it shows application of risk indicators in a multi-criterion analysis using respectively self organizing mapping and partial order technique in a comparative analysis that highlights critical aspects of uncertainty, due to the ambiguity between single risk indicator rankings. Copyright 2009 Elsevier B.V. All rights reserved.

  5. In situ monitoring of soil dissolution dynamics: a rapid and simple method for determining worst-case soils for cleaning validation.

    PubMed

    Sharnez, Rizwan; Lathia, Justin; Kahlenberg, David; Prabhu, Sunil; Dekleva, Michael

    2004-01-01

    A common approach utilized in validating the cleaning of multi-product equipment is to challenge the cleaning cycle with the hardest-to-clean, or "worst-case", soil. The worst-case soil is often determined through bench-scale experiments. These experiments can be tricky and time-consuming, especially when the dissolution dynamics of the soils are characterized by crossovers beyond the limit of visual detection. This paper describes a simple in situ method for monitoring soil dissolution dynamics and rapidly determining worst-case soils for cleaning validation. The method utilizes the real-time response of electrical conductivity to identify crossovers and to determine the optimal time for endpoint analysis. The results address the sensitivity and reproducibility of the method and the identification of critical experimental parameters. The dissolution dynamics of several parenteral products are compared.

  6. Earth Observing System (EOS)/Advanced Microwave Sounding Unit-A (AMSU-A) worst-case analysis: Antenna beam pointing

    NASA Technical Reports Server (NTRS)

    Ely, Wayne

    1994-01-01

    This report presents a worst-case analysis of the EOS/AMSU-A (Earth Observing System/Advanced Microwave Sounding Unit-A) Antenna beam-pointing accuracy. There are three sources of beam pointing error. These are mechanical tolerances in the manufacture and assembly of the parts, allowable axial displacement of the reflector relative to the motor shaft, and on-orbit thermal distortions. For the worst-case analysis, each will be assumed to act independently and thus each contribution is additive.

  7. Conceptual modeling for identification of worst case conditions in environmental risk assessment of nanomaterials using nZVI and C60 as case studies.

    PubMed

    Grieger, Khara D; Hansen, Steffen F; Sørensen, Peter B; Baun, Anders

    2011-09-01

    Conducting environmental risk assessment of engineered nanomaterials has been an extremely challenging endeavor thus far. Moreover, recent findings from the nano-risk scientific community indicate that it is unlikely that many of these challenges will be easily resolved in the near future, especially given the vast variety and complexity of nanomaterials and their applications. As an approach to help optimize environmental risk assessments of nanomaterials, we apply the Worst-Case Definition (WCD) model to identify best estimates for worst-case conditions of environmental risks of two case studies which use engineered nanoparticles, namely nZVI in soil and groundwater remediation and C(60) in an engine oil lubricant. Results generated from this analysis may ultimately help prioritize research areas for environmental risk assessments of nZVI and C(60) in these applications as well as demonstrate the use of worst-case conditions to optimize future research efforts for other nanomaterials. Through the application of the WCD model, we find that the most probable worst-case conditions for both case studies include i) active uptake mechanisms, ii) accumulation in organisms, iii) ecotoxicological response mechanisms such as reactive oxygen species (ROS) production and cell membrane damage or disruption, iv) surface properties of nZVI and C(60), and v) acute exposure tolerance of organisms. Additional estimates of worst-case conditions for C(60) also include the physical location of C(60) in the environment from surface run-off, cellular exposure routes for heterotrophic organisms, and the presence of light to amplify adverse effects. Based on results of this analysis, we recommend the prioritization of research for the selected applications within the following areas: organism active uptake ability of nZVI and C(60) and ecotoxicological response end-points and response mechanisms including ROS production and cell membrane damage, full nanomaterial characterization taking

  8. "Best Case/Worst Case": Training Surgeons to Use a Novel Communication Tool for High-Risk Acute Surgical Problems.

    PubMed

    Kruser, Jacqueline M; Taylor, Lauren J; Campbell, Toby C; Zelenski, Amy; Johnson, Sara K; Nabozny, Michael J; Steffens, Nicole M; Tucholka, Jennifer L; Kwekkeboom, Kris L; Schwarze, Margaret L

    2017-04-01

    Older adults often have surgery in the months preceding death, which can initiate postoperative treatments inconsistent with end-of-life values. "Best Case/Worst Case" (BC/WC) is a communication tool designed to promote goal-concordant care during discussions about high-risk surgery. The objective of this study was to evaluate a structured training program designed to teach surgeons how to use BC/WC. Twenty-five surgeons from one tertiary care hospital completed a two-hour training session followed by individual coaching. We audio-recorded surgeons using BC/WC with standardized patients and 20 hospitalized patients. Hospitalized patients and their families participated in an open-ended interview 30 to 120 days after enrollment. We used a checklist of 11 BC/WC elements to measure tool fidelity and surgeons completed the Practitioner Opinion Survey to measure acceptability of the tool. We used qualitative analysis to evaluate variability in tool content and to characterize patient and family perceptions of the tool. Surgeons completed a median of 10 of 11 BC/WC elements with both standardized and hospitalized patients (range 5-11). We found moderate variability in presentation of treatment options and description of outcomes. Three months after training, 79% of surgeons reported BC/WC is better than their usual approach and 71% endorsed active use of BC/WC in clinical practice. Patients and families found that BC/WC established expectations, provided clarity, and facilitated deliberation. Surgeons can learn to use BC/WC with older patients considering acute high-risk surgical interventions. Surgeons, patients, and family members endorse BC/WC as a strategy to support complex decision making. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  9. Scenario planning.

    PubMed

    Enzmann, Dieter R; Beauchamp, Norman J; Norbash, Alexander

    2011-03-01

    In facing future developments in health care, scenario planning offers a complementary approach to traditional strategic planning. Whereas traditional strategic planning typically consists of predicting the future at a single point on a chosen time horizon and mapping the preferred plans to address such a future, scenario planning creates stories about multiple likely potential futures on a given time horizon and maps the preferred plans to address the multiple described potential futures. Each scenario is purposefully different and specifically not a consensus worst-case, average, or best-case forecast; nor is scenario planning a process in probabilistic prediction. Scenario planning focuses on high-impact, uncertain driving forces that in the authors' example affect the field of radiology. Uncertainty is the key concept as these forces are mapped onto axes of uncertainty, the poles of which have opposed effects on radiology. One chosen axis was "market focus," with poles of centralized health care (government control) vs a decentralized private market. Another axis was "radiology's business model," with one pole being a unified, single specialty vs a splintered, disaggregated subspecialty. The third axis was "technology and science," with one pole representing technology enabling to radiology vs technology threatening to radiology. Selected poles of these axes were then combined to create 3 scenarios. One scenario, termed "entrepreneurialism," consisted of a decentralized private market, a disaggregated business model, and threatening technology and science. A second scenario, termed "socialized medicine," had a centralized market focus, a unified specialty business model, and enabling technology and science. A third scenario, termed "freefall," had a centralized market focus, a disaggregated business model, and threatening technology and science. These scenarios provide a range of futures that ultimately allow the identification of defined "signposts" that can

  10. 41 CFR 102-80.150 - What is meant by “reasonable worst case fire scenario”?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... quantitative analysis of the probability of occurrence of each scenario and combination of events will be...., furniture, trash, paper, chemicals), potential fire ignition locations (e.g., bedroom, office,...

  11. 41 CFR 102-80.150 - What is meant by “reasonable worst case fire scenario”?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... quantitative analysis of the probability of occurrence of each scenario and combination of events will be...., furniture, trash, paper, chemicals), potential fire ignition locations (e.g., bedroom, office,...

  12. 41 CFR 102-80.150 - What is meant by “reasonable worst case fire scenario”?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... quantitative analysis of the probability of occurrence of each scenario and combination of events will be...., furniture, trash, paper, chemicals), potential fire ignition locations (e.g., bedroom, office,...

  13. Making the most of the worst-case scenario: should belt-positioning booster seats be used in lap-belt-only seating positions?

    PubMed

    Kirley, Bevan B; Teoh, Eric R; Lund, Adrian K; Arbogast, Kristy B; Kallan, Michael J; Durbin, Dennis R

    2009-12-01

    Examine real-world crash injury data to determine whether children seated with lap belts only are better protected with or without belt-positioning booster seats. Crash injury rates among booster-age children were examined for three restraint categories: lap belt only, belt-positioning booster seat with lap belt, and booster seat with lap/shoulder belt. Data were drawn from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) and the Partners for Child Passenger Safety (PCPS) crash surveillance system for years 1997-2006 and 1998-2006, respectively. Main outcome measures were the percentage of crash-involved booster-age children with moderate or greater injury (maximum abbreviated injury score [MAIS] 2+). The estimated risk of MAIS 2+ injury among children restrained with lap belts and boosters was 0.12 percent (NASS-CDS) and 0.96 percent (PCPS), compared with 1.21 and 1.74 percent, respectively, for lap belts only. This difference was not significant due to small numbers of children in lap belts with boosters. In PCPS, children restrained by lap/shoulder belts and boosters had lower injury risk than children restrained by lap belts, with or without boosters. Although data for children secured in lap belts with boosters are limited, the results suggest that boosters are not harmful. This finding is inconsistent with the current recommendation that booster seats not be used when children must be buckled with lap belts only. Data also confirm that booster seats with lap/shoulder belts remain the optimal protection for booster-age children.

  14. Conscious worst case definition for risk assessment, part I: a knowledge mapping approach for defining most critical risk factors in integrative risk management of chemicals and nanomaterials.

    PubMed

    Sørensen, Peter B; Thomsen, Marianne; Assmuth, Timo; Grieger, Khara D; Baun, Anders

    2010-08-15

    This paper helps bridge the gap between scientists and other stakeholders in the areas of human and environmental risk management of chemicals and engineered nanomaterials. This connection is needed due to the evolution of stakeholder awareness and scientific progress related to human and environmental health which involves complex methodological demands on risk management. At the same time, the available scientific knowledge is also becoming more scattered across multiple scientific disciplines. Hence, the understanding of potentially risky situations is increasingly multifaceted, which again challenges risk assessors in terms of giving the 'right' relative priority to the multitude of contributing risk factors. A critical issue is therefore to develop procedures that can identify and evaluate worst case risk conditions which may be input to risk level predictions. Therefore, this paper suggests a conceptual modelling procedure that is able to define appropriate worst case conditions in complex risk management. The result of the analysis is an assembly of system models, denoted the Worst Case Definition (WCD) model, to set up and evaluate the conditions of multi-dimensional risk identification and risk quantification. The model can help optimize risk assessment planning by initial screening level analyses and guiding quantitative assessment in relation to knowledge needs for better decision support concerning environmental and human health protection or risk reduction. The WCD model facilitates the evaluation of fundamental uncertainty using knowledge mapping principles and techniques in a way that can improve a complete uncertainty analysis. Ultimately, the WCD is applicable for describing risk contributing factors in relation to many different types of risk management problems since it transparently and effectively handles assumptions and definitions and allows the integration of different forms of knowledge, thereby supporting the inclusion of multifaceted risk

  15. Worst-Case GPS Scintillations on the Ground Estimated from Radio Occultation Observations of FORMOSAT-3/COSMIC During 2007-2014

    NASA Astrophysics Data System (ADS)

    Liu, J. Y.; Chen, S. P.; Yeh, W. H.; Tsai, H. F.; Rajesh, P. K.

    2016-07-01

    The FORMOSAT-3/COSMIC (F3/C) satellite probes the S4 scintillation index profile of GPS signals by using the radio occultation (RO) technique. In this study, for practical use on the Earth's surface, a method is developed to convert and integrate the probed RO S4 index, so obtaining the scintillation on the ground. To estimate the worst case, the maximum value on each profile probed by F3/C, which is termed S4max, is isolated. The isolated data are further used to construct the global three-dimensional distributions of S4max for various local times, seasons, solar activities, and locations. The converted S4max for the first time estimates the global distribution of ionospheric scintillations in the GPS L1 band C/A code signal on the ground. The results show that the worst-case scintillations appear within the low-latitude region of ±30°N, peaking around ±20°N magnetic latitude; they begin at 1900 MLT, reach their maximum at 2100 MLT, and vanish by about 0200-0300 MLT. The most pronounced low-latitude scintillation occurs over the South American and African sectors.

  16. Adhesive strength of total knee endoprostheses to bone cement - analysis of metallic and ceramic femoral components under worst-case conditions.

    PubMed

    Bergschmidt, Philipp; Dammer, Rebecca; Zietz, Carmen; Finze, Susanne; Mittelmeier, Wolfram; Bader, Rainer

    2016-06-01

    Evaluation of the adhesive strength of femoral components to the bone cement is a relevant parameter for predicting implant safety. In the present experimental study, three types of cemented femoral components (metallic, ceramic and silica/silane-layered ceramic) of the bicondylar Multigen Plus knee system, implanted on composite femora were analysed. A pull-off test with the femoral components was performed after different load and several cementing conditions (four groups and n=3 components of each metallic, ceramic and silica/silane-layered ceramic in each group). Pull-off forces were comparable for the metallic and the silica/silane-layered ceramic femoral components (mean 4769 N and 4298 N) under standard test condition, whereas uncoated ceramic femoral components showed reduced pull-off forces (mean 2322 N). Loading under worst-case conditions led to decreased adhesive strength by loosening of the interface implant and bone cement using uncoated metallic and ceramic femoral components, respectively. Silica/silane-coated ceramic components were stably fixed even under worst-case conditions. Loading under high flexion angles can induce interfacial tensile stress, which could promote early implant loosening. In conclusion, a silica/silane-coating layer on the femoral component increased their adhesive strength to bone cement. Thicker cement mantles (>2 mm) reduce adhesive strength of the femoral component and can increase the risk of cement break-off.

  17. Performance of a normalized energy metric without jammer state information for an FH/MFSK system in worst case partial band jamming

    NASA Technical Reports Server (NTRS)

    Lee, P. J.

    1985-01-01

    For a frequency-hopped noncoherent MFSK communication system without jammer state information (JSI) in a worst case partial band jamming environment, it is well known that the use of a conventional unquantized metric results in very poor performance. In this paper, a 'normalized' unquantized energy metric is suggested for such a system. It is shown that with this metric, one can save 2-3 dB in required signal energy over the system with hard decision metric without JSI for the same desired performance. When this very robust metric is compared to the conventional unquantized energy metric with JSI, the loss in required signal energy is shown to be small. Thus, the use of this normalized metric provides performance comparable to systems for which JSI is known. Cutoff rate and bit error rate with dual-k coding are used for the performance measures.

  18. Performance of a normalized energy metric without jammer state information for an FH/MFSK system in worst case partial band jamming

    NASA Technical Reports Server (NTRS)

    Lee, P. J.

    1985-01-01

    For a frequency-hopped noncoherent MFSK communication system without jammer state information (JSI) in a worst case partial band jamming environment, it is well known that the use of a conventional unquantized metric results in very poor performance. In this paper, a 'normalized' unquantized energy metric is suggested for such a system. It is shown that with this metric, one can save 2-3 dB in required signal energy over the system with hard decision metric without JSI for the same desired performance. When this very robust metric is compared to the conventional unquantized energy metric with JSI, the loss in required signal energy is shown to be small. Thus, the use of this normalized metric provides performance comparable to systems for which JSI is known. Cutoff rate and bit error rate with dual-k coding are used for the performance measures.

  19. Direct HIV cytopathicity cannot account for CD4 decline in AIDS in the presence of homeostasis: a worst-case dynamic analysis.

    PubMed

    Anderson, R W; Ascher, M S; Sheppard, H W

    1998-03-01

    The central paradox of HIV pathogenesis is that the viral burden, either free or cellular, seems too low to deplete the CD4 population by direct killing. Until recently, little data could be used to compare direct and indirect pathogenic theories critically. Clinical trials with potent new antiviral agents have measured important kinetic parameters of HIV infection, including viral and infected cell half-lives. This has led to the construction of explicit models of direct killing. Using a worst-case dynamic analysis, we show that such cytopathic models are untenable. Rates of infected cell removal are orders of magnitude too low to suppress steady state CD4 counts significantly in the face of lymphocyte replenishment, especially in early infection. Furthermore, the direct cytopathic models, as proposed, predict an extremely variable disease course across the broad range of observed viral burdens (five orders of magnitude), which is inconsistent with the relatively small differences in disease progression observed between patients. In contrast, immunologic theories of pathogenesis, such as homeostatic dysregulation based on immune activation, do not suffer from these difficulties and are more consistent with the natural history of HIV infection.

  20. Acute Exposure to Worst-Case Concentrations of Amitraz Does Not Affect Honey Bee Learning, Short-Term Memory, or Hemolymph Octopamine Levels.

    PubMed

    Rix, Rachel R; Christopher Cutler, G

    2017-02-01

    Amitraz, an acaricide used to treat Varroa destructor Anderson & Trueman, is one of the most commonly detected pesticides in honey bee (Apis mellifera L.) hives. Acaricides sometimes negatively impact honey bee cognition, but potential effects of amitraz on honey bee learning have been rarely studied. We topically exposed foragers to 95th percentile field-relevant levels of amitraz and, 24 h later, tested the ability of bees to associate a sucrose reward with a conditioned odor (learning response) using the proboscis extension response (PER). We then tested the ability of the bees to retain this memory 1 h and 2 h post-conditioning. Because amitraz is thought to affect octopamine metabolism in honey bees, and because octopamine is directly related to honey bee learning and memory, we also examined effects of exposure to amitraz on octopamine levels in honey bee hemolymph. We found that acute exposure to 95th percentile doses of amitraz had no impact on honey bee learning or short-term memory as measured by PER. Concentrations of octopamine in hemolymph from our low amitraz treatment were 1.4-fold higher than control levels, but other treatments had no effect. Our results from worst-case acute exposure experiments with worker bees in the laboratory suggest that typical field-relevant (within hive) exposures to amitraz probably have little effect on honey bee learning and memory. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. The development of alternative case scenarios for hazard analyses under {section}112(r)(7)

    SciTech Connect

    Egan, B.A.; Yuhas, J.A.

    1997-12-31

    EPA`s 112(r)(7) rule, which requires the preparation of Risk Management Plans, requires sources to perform offsite consequence analyses for a worst case release scenario and also for alternative (more likely to occur) scenarios. The worst case scenarios are well defined by the regulation and will be recognized for most situations as over predicting the potential impact of a release major factors. Model selection does have an effect on calculated distances to toxic endpoints. However, as is shown, the magnitude of these results does not vary greatly. The need to define alternative scenarios presents an opportunity for sources to consider much more carefully what a more likely to occur (although, hopefully also improbable) accident might pose as a threat to the public. Precautionary and preventative as well as mitigative measures become more important to the actual safety of the public.

  2. Mission Scenario Development Workbench

    NASA Technical Reports Server (NTRS)

    Kordon, Mark; Baker, John; Gilbert, John; Hanks, David; Mandutianu, Dan; Hooper, David

    2006-01-01

    The Mission Scenario Development Workbench (MSDW) is a multidisciplinary performance analysis software tool for planning and optimizing space missions. It provides a number of new capabilities that are particularly useful for planning the surface activities on other planets. MSDW enables rapid planning of a space mission and supports flight system and scientific-instrumentation trades. It also provides an estimate of the ability of flight, ground, and science systems to meet high-level mission goals and provides means of evaluating expected mission performance at an early stage of planning in the project life cycle. In MSDW, activity plans and equipment-list spreadsheets are integrated with validated parameterized simulation models of spacecraft systems. In contrast to traditional approaches involving worst-case estimates with large margins, the approach embodied in MSDW affords more flexibility and more credible results early in the lifecycle through the use of validated, variable- fidelity models of spacecraft systems. MSDW is expected to help maximize the scientific return on investment for space missions by understanding early the performance required to have a successful mission while reducing the risk of costly design changes made at late stages in the project life cycle.

  3. Scenario-based tsunami hazard assessment for the coast of Vietnam from the Manila Trench source

    NASA Astrophysics Data System (ADS)

    Hong Nguyen, Phuong; Cong Bui, Que; Ha Vu, Phuong; The Pham, Truyen

    2014-11-01

    This paper assesses the impact of tsunamis in the East Vietnam Sea potentially originated from a giant rupture along the Manila Trench to the Vietnamese coast. Tsunami heights and arrival times to the major forecast points along the Vietnamese coast are computed using COMCOT model. The results of the worst case scenario (Mw = 9.3) and two extreme scenarios were used to assess the tsunami hazards. The simulation results show that Vietnamese coast can be divided into three parts with different levels of tsunami hazard. The highest threat exists along the coasts of Central and North-Central Vietnam, from Quang Binh to Ba Ria - Vung Tau provinces, with maximum wave height of 18 m observed near Quang Ngai coast, and a tsunami would reach this coastline in two hours at the earliest. The northern coastal zone of Vietnam has lower tsunami hazard. In the worst case scenario, maximum amplitudes of tsunami waves at Hai Phong sea port and Nam Dinh city, North Vietnam, are 3.5 m and 3.7 m, respectively, while the travel times to these sites are much longer, over 8 h. The southern coastal zone of Vietnam has very low tsunami hazard. In the worst case scenario, the maximum amplitude at Ca Mau is 0.12 m, while the travel time is over 10 h.

  4. Worst case scenario: Investigation of the suitability of high frequency velocity and pressure methodologies to identify the flow conditions most likely to induce bedrock scour downstream from a dam

    NASA Astrophysics Data System (ADS)

    Humphries, R. P.; Rock, A.; Annandale, G. W.

    2011-12-01

    Erosion of bedrock by highly turbulent flows immediately downstream from dams can be detrimental to the stability of their structure. Therefore, determining the flow condition that induces maximum scour is a critical component of dam design analysis. Here, we investigate the suitability of two data collection methods for the purpose of assessing the occurrence and magnitude of scour. High temporal and spatial resolution data, collected simultaneously using both a 2-dimensional acoustic Doppler velocimeter (ADV), and a flush mounted pressure transducer, are used to assess the potential for bedrock scour. We present the results of a physical model designed to simulate conditions downstream of a dam where penstocks discharge highly turbulent flows onto a bedrock outcrop. Preliminary results display a strong correlation between the turbulent characteristics of both data sets, indicating their ability to characterize the properties of the flow. However, the results of spectral analysis of both wave forms illustrate the greater suitability of the ADV to capture the turbulent properties of the flow conditions at lower discharges, without the interference of the boundary. Unfortunately, lower signal strength adversely affects the quality of the ADV results in more turbulent flows, thus advocating for the use of the pressure data under more turbulent conditions. Additionally, results also indicate the backwater effect that increases flow depth in the discharge basin has a dampening effect on the turbulent flow properties of the highest discharges, producing a non-linear correlation between scour potential and discharge.

  5. Melorheostosis mimicking synovial osteochondromatosis.

    PubMed

    Wadhwa, Vibhor; Chhabra, Avneesh; Samet, Jonathan D

    2014-01-01

    Melorheostosis is an uncommon, sporadic, sclerosing bone lesion that may affect the adjacent soft tissues. It has been associated with many entities such as osteopoikilosis, soft tissue vascular malformations, bone and soft tissue tumors, nephrotic syndrome, segmental limb contractures, osteosarcoma, desmoid tumor, and mesenteric fibromatosis. Synovial osteochondromatosis is a benign neoplasia of the hyaline cartilage presenting as nodules in the subsynovial tissue of a joint or tendon sheath. The intra-articular extension of melorheostosis mimicking synovial osteochondromatosis has not been reported before. In this article, the authors describe an unusual case mimicking synovial chondromatosis arising as a result of melorheostosis and their characteristic imaging findings.

  6. Ethoprophos fate on soil-water interface and effects on non-target terrestrial and aquatic biota under Mediterranean crop-based scenarios.

    PubMed

    Leitão, Sara; Moreira-Santos, Matilde; Van den Brink, Paul J; Ribeiro, Rui; José Cerejeira, M; Sousa, José Paulo

    2014-05-01

    The present study aimed to assess the environmental fate of the insecticide and nematicide ethoprophos in the soil-water interface following the pesticide application in simulated maize and potato crops under Mediterranean agricultural conditions, particularly of irrigation. Focus was given to the soil-water transfer pathways (leaching and runoff), to the pesticide transport in soil between pesticide application (crop row) and non-application areas (between crop rows), as well as to toxic effects of the various matrices on terrestrial and aquatic biota. A semi-field methodology mimicking a "worst-case" ethoprophos application (twice the recommended dosage for maize and potato crops: 100% concentration v/v) in agricultural field situations was used, in order to mimic a possible misuse by the farmer under realistic conditions. A rainfall was simulated under a slope of 20° for both crop-based scenarios. Soil and water samples were collected for the analysis of pesticide residues. Ecotoxicity of soil and aquatic samples was assessed by performing lethal and sublethal bioassays with organisms from different trophic levels: the collembolan Folsomia candida, the earthworm Eisenia andrei and the cladoceran Daphnia magna. Although the majority of ethoprophos sorbed to the soil application area, pesticide concentrations were detected in all water matrices illustrating pesticide transfer pathways of water contamination between environmental compartments. Leaching to groundwater proved to be an important transfer pathway of ethoprophos under both crop-based scenarios, as it resulted in high pesticide concentration in leachates from Maize (130µgL(-1)) and Potato (630µgL(-1)) crop scenarios, respectively. Ethoprophos application at the Potato crop scenario caused more toxic effects on terrestrial and aquatic biota than at the Maize scenario at the recommended dosage and lower concentrations. In both crop-based scenarios, ethoprophos moved with the irrigation water flow to the

  7. Worldwide variations in the lifetime probability of reproductive cancer in women: implications of best-case, worst-case, and likely-case assumptions about the effect of oral contraceptive use.

    PubMed

    Petitti, D B; Porterfield, D

    1992-02-01

    Cancer incidence in countries representative of three patterns of reproductive cancer and age-specific mortality was used to estimate the effect of oral contraceptive use on the lifetime probability of reproductive cancer under three sets of assumptions about the effects of oral contraceptives. Under the set of assumptions considered likely, oral contraceptives were estimated to reduce or increase only slightly the lifetime probability of any reproductive cancer in each setting. Under worst-case assumptions, oral contraceptives were estimated to increase the lifetime probability of reproductive cancer only modestly in settings with low cancer rates and in settings with high rates of breast, ovarian, and endometrial cancer, but it might have a large impact on lifetime probability of reproductive cancer in settings with high cervical cancer rates. Under best-case assumptions, oral contraceptives were estimated to decrease the lifetime probability of reproductive cancer in each setting; this reduction was estimated to be greatest in settings where endometrial and ovarian cancer incidence are high.

  8. Urticaria mimickers in children.

    PubMed

    Mathur, Anubhav N; Mathes, Erin F

    2013-01-01

    Acute urticaria is a self-limited cutaneous condition marked by transient, erythematous, and pruritic wheals. It is a hypersensitivity response that is often secondary to infection, medications, or food allergies in children. In contrast, the urticarial "mimickers" described in this review article are often seen in the context of fever and extracutaneous manifestations in pediatric patients. The differential diagnosis ranges from benign and self-limited hypersensitivity responses to multisystem inflammatory diseases. Establishing the correct diagnosis of an urticarial rash in a pediatric patient is necessary to both prevent an unnecessary work up for self-limited conditions and to appropriately recognize and evaluate multisystem inflammatory disorders. Herein, we describe two cases to illustrate the clinical manifestations, laboratory findings, histopathology and differential diagnoses for several mimickers of acute urticaria including: urticaria multiforme, serum sickness like reaction, Henoch-Schönlein purpura, acute hemorrhagic edema of infancy, systemic onset juvenile idiopathic arthritis, cryopyrin associated periodic syndromes, and urticarial vasculitis. © 2013 Wiley Periodicals, Inc.

  9. Arctic Planning Scenarios: Scenario #1: Defence Scenario

    DTIC Science & Technology

    2011-07-01

    ministre de la Défense nationale, 2011 Abstract With the change in northern climate over the past decade, current policy and media discussions have...scenarios, a scenario development methodology, and a Capability Inventory Tool (CIT) to identify and characterize legislation and policy on the Arctic, with...for Canada to be able to meet its strategy and policy objectives. Résumé Compte tenu des changements survenus dans le climat nordique au cours des

  10. Dark scenarios

    NASA Astrophysics Data System (ADS)

    Ahonen, Pasi; Alahuhta, Petteri; Daskala, Barbara; Delaitre, Sabine; Hert, Paul De; Lindner, Ralf; Maghiros, Ioannis; Moscibroda, Anna; Schreurs, Wim; Verlinden, Michiel

    In this chapter, we present four "dark scenarios" that highlight the key socio-economic, legal, technological and ethical risks to privacy, identity, trust, security and inclusiveness posed by new AmI technologies. We call them dark scenarios, because they show things that could go wrong in an AmI world, because they present visions of the future that we do not want to become reality. The scenarios expose threats and vulnerabilities as a way to inform policy-makers and planners about issues they need to take into account in developing new policies or updating existing legislation. Before presenting the four scenarios and our analysis of each, we describe the process of how we created the scenarios as well as the elements in our methodology for analysing the scenarios.

  11. Long-lasting permethrin-impregnated clothing: protective efficacy against malaria in hyperendemic foci, and laundering, wearing, and weathering effects on residual bioactivity after worst-case use in the rain forests of French Guiana.

    PubMed

    Most, Bruno; Pommier de Santi, Vincent; Pagès, Frédéric; Mura, Marie; Uedelhoven, Waltraud M; Faulde, Michael K

    2017-02-01

    Personal protective measures against hematophagous vectors constitute the first line of defense against arthropod-borne diseases. However, guidelines for the standardized testing and licensing of insecticide-treated clothing are still lacking. The aim of this study was to analyze the preventive effect of long-lasting polymer-coated permethrin-impregnated clothing (PTBDU) against malaria after exposure to high-level disease transmission sites as well as the corresponding loss of permethrin and bioactivity during worst-case field use. Between August 2011 and June 2012, 25 personnel wearing PTBDUs and exposed for 9.5 person-months in hyperendemic malaria foci in the rain forest of French Guiana contracted no cases of malaria, whereas 125 persons wearing untreated uniforms only, exposed for 30.5 person-months, contracted 11 cases of malaria, indicating that PTBDU use significantly (p = 0.0139) protected against malaria infection. In the field, PTBDUs were laundered between 1 and 218 times (mean 25.2 ± 44.8). After field use, the mean remaining permethrin concentration in PTBDU fabric was 732.1 ± 321.1 min varying between 130 and 1270 mg/m(2) (mean 743.9 ± 304.2 mg/m(2)) in blouses, and between 95 and 1290 mg/m(2) (mean 720.2 ± 336.9 mg/m(2)) in trousers. Corresponding bioactivity, measured according to internal licensing conditions as KD99 times against Aedes aegypti mosquitoes, varied between 27.5 and 142.5 min (mean 47.7 ± 22.1 min) for blouses, and between 25.0 and 360 min (mean 60.2 ± 66.1 min) for trousers. We strongly recommend the use of long-lasting permethrin-impregnated clothing for the prevention of mosquito-borne diseases, including chikungunya, dengue, and zika fevers, which are currently resurging globally.

  12. Mimicking the Moon

    NASA Image and Video Library

    2014-11-03

    When Galileo first observed Venus displaying a crescent phase, he excitedly wrote to Kepler (in anagram) of Venus mimicking the moon-goddess. He would have been delirious with joy to see Saturn and Titan, seen in this image, doing the same thing. More than just pretty pictures, high-phase observations -- taken looking generally toward the Sun, as in this image -- are very powerful scientifically since the way atmospheres and rings transmit sunlight is often diagnostic of compositions and physical states. In this example, Titan's crescent nearly encircles its disk due to the small haze particles high in its atmosphere refracting the incoming light of the distant Sun. This view looks toward the sunlit side of the rings from about 3 degrees above the ringplane. The image was taken in violet light with the Cassini spacecraft wide-angle camera on Aug. 11, 2013. The view was obtained at a distance of approximately 1.1 million miles (1.7 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 154 degrees. Image scale is 64 miles (103 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18291

  13. Dirofilariasis Mimicking an Acute Scrotum.

    PubMed

    Bertozzi, Mirko; Rinaldi, Victoria Elisa; Prestipino, Marco; Giovenali, Paolo; Appignani, Antonino

    2015-10-01

    Human infections caused by Dirofilaria repens have been reported in many areas of the world. We describe a case of a 3-year-old child with an intrascrotal mass caused by D repens mimicking an acute scrotum. This represents the first case of scrotal dirofilariasis described in pediatric age with such an unusual presentation.

  14. Xanthogranulomatous cholecystitis mimicking gallbladder cancer.

    PubMed

    Ewelukwa, Ofor; Ali, Omair; Akram, Salma

    2014-05-08

    Xanthogranulomatous cholecystitis (XGC) is a benign, uncommon variant of chronic cholecystitis characterised by focal or diffuse destructive inflammatory process of the gallbladder (GB). Macroscopically, it appears like yellowish tumour-like masses in the wall of the GB. This article reports on a 74-year-old woman with XGC mimicking GB cancer.

  15. Missed Appendicitis: Mimicking Urologic Symptoms

    PubMed Central

    Akhavizadegan, Hamed

    2012-01-01

    Appendicitis, a common disease, has different presentations. This has made its diagnosis difficult. This paper aims to present two cases of missed appendicitis with completely urologic presentation and the way that helped us to reach the correct diagnosis. The first case with symptoms fully related to kidney and the second mimicking epididymorchitis hindered prompt diagnosis. Right site of the pain, relapsing fever, frequent physical examination, and resistance to medical treatment were main clues which help us to make correct diagnosis. PMID:23326748

  16. Megakaryocytes mimicking metastatic breast carcinoma.

    PubMed

    Hoda, Syed A; Resetkova, Erika; Yusuf, Yasmin; Cahan, Anthony; Rosen, Paul P

    2002-05-01

    False-positive diagnosis of lymph nodes occurs when a benign element in a lymph node, or in its capsule, is interpreted as metastatic carcinoma. This report describes a patient with breast carcinoma who had megakaryocytes in axillary sentinel lymph nodes mimicking metastatic carcinoma. The patient had no history of a hematologic disease, and we found no evidence of a concurrent hematopoietic disorder. The megakaryocytes were reactive for CD31, CD61, and von Willebrand factor, but not for cytokeratin (AE1/AE3). Megakaryocytes should be added to the list of benign histologic abnormalities that may simulate metastatic carcinoma in a sentinel lymph node.

  17. Norwegian scabies mimicking rupioid psoriasis*

    PubMed Central

    Costa, Juliana Bastos; de Sousa, Virna Lygia Lobo Rocha; da Trindade Neto, Pedro Bezerra; Paulo Filho, Thomás de Aquino; Cabral, Virgínia Célia Dias Florêncio; Pinheiro, Patrícia Moura Rossiter

    2012-01-01

    Norwegian scabies is a highly contagious skin infestation caused by an ectoparasite, Scarcoptes scabiei var. Hominis, which mainly affects immunosuppressed individuals. Clinically, it may simulate various dermatoses such as psoriasis, Darier's disease, seborrheic dermatitis, among others. This is a case report of a 33-year-old woman, immunocompetent, diagnosed with generalized anxiety disorder (cancer phobia), who had erythematous, well-defined plaques, covered with rupioid crusts, on her neck, axillary folds, breast, periumbilical region, groin area, besides upper back and elbows, mimicking an extremely rare variant of psoriasis, denominated rupioid psoriasis. PMID:23197214

  18. Tinea capitis mimicking folliculitis decalvans.

    PubMed

    Tangjaturonrusamee, C; Piraccini, B M; Vincenzi, C; Starace, M; Tosti, A

    2011-01-01

    We report on an adult patient with tinea capitis caused by Microsporum canis, who presented with diffuse alopecia and follicular pustules, mimicking folliculitis decalvans. Examination of the scalp showed severe alopecia with prominent involvement of the frontal and vertex scalp: the skin was markedly erythematous with pustules and brownish crusts. Videodermoscopy revealed visible follicular ostia, numerous pustular lesions and several comma hairs. Fluconazole 150 mg a week for 8 weeks associated with ketoconazole shampoo cleared the inflammatory lesions and produced complete hair regrowth. © 2009 Blackwell Verlag GmbH.

  19. The great mimickers of rosacea.

    PubMed

    Olazagasti, Jeannette; Lynch, Peter; Fazel, Nasim

    2014-07-01

    Although rosacea is one of the most common conditions treated by dermatologists, it also is one of the most misunderstood. It is a chronic disorder affecting the central parts of the face and is characterized by frequent flushing; persistent erythema (ie, lasting for at least 3 months); telangiectasia; and interspersed episodes of inflammation with swelling, papules, and pustules. Understanding the clinical variants and disease course of rosacea is important to differentiate this entity from other conditions that can mimic rosacea. Herein we present several mimickers of rosacea that physicians should consider when diagnosing this condition.

  20. Splenic inflammatory pseudotumor mimicking angiosarcoma.

    PubMed

    Hsu, Chao-Wen; Lin, Chieh-Hsin; Yang, Tsung-Lung; Chang, Hong-Tai

    2008-11-07

    Splenic tumors are rare. Differentiation of the tumors before operation is of great value regarding the outcome. A case of a 32-year-old man with a splenic inflammatory pseudotumor (IPT) mimicking splenic angiosarcoma is described. The tumor was highly suspected of being splenic angiosarcoma based on radiological findings preoperatively. However, after splenectomy, histopathological examinations revealed splenic IPT. Splenic IPT and angiosarcoma are rare and often pose diagnostic difficulties because the clinical and radiological findings are obscure. Due to large differences in prognosis, we briefly reviewed the clinical, radiological, and pathological features of both of the tumors.

  1. Splenic inflammatory pseudotumor mimicking angiosarcoma

    PubMed Central

    Hsu, Chao-Wen; Lin, Chieh-Hsin; Yang, Tsung-Lung; Chang, Hong-Tai

    2008-01-01

    Splenic tumors are rare. Differentiation of the tumors before operation is of great value regarding the outcome. A case of a 32-year-old man with a splenic inflammatory pseudotumor (IPT) mimicking splenic angiosarcoma is described. The tumor was highly suspected of being splenic angiosarcoma based on radiological findings preoperatively. However, after splenectomy, histopathological examinations revealed splenic IPT. Splenic IPT and angiosarcoma are rare and often pose diagnostic difficulties because the clinical and radiological findings are obscure. Due to large differences in prognosis, we briefly reviewed the clinical, radiological, and pathological features of both of the tumors. PMID:19009664

  2. Inverse heat mimicking of given objects

    NASA Astrophysics Data System (ADS)

    Alwakil, Ahmed; Zerrad, Myriam; Bellieud, Michel; Amra, Claude

    2017-03-01

    We address a general inverse mimicking problem in heat conduction. The objects to cloak and mimic are chosen beforehand; these objects identify a specific set of space transformations. The shapes that can be mimicked are derived from the conductivity matrices. Numerical calculation confirms all of the analytical predictions. The technique provides key advantages for applications and can be extended to the field of waves.

  3. Challenging mimickers of primary systemic vasculitis.

    PubMed

    Miloslavsky, Eli M; Stone, John H; Unizony, Sebastian H

    2015-01-01

    The need to distinguish true primary systemic vasculitis from its multiple potential mimickers is one of the most challenging diagnostic conundrums in clinical medicine. This article reviews 9 challenging vasculitis mimickers: fibromuscular dysplasia, calciphylaxis, segmental arterial mediolysis, antiphospholipid syndrome, hypereosinophilic syndrome, lymphomatoid granulomatosis, malignant atrophic papulosis, livedoid vasculopathy, and immunoglobulin G4-related disease.

  4. Black hole mimickers: Regular versus singular behavior

    SciTech Connect

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2008-07-15

    Black hole mimickers are possible alternatives to black holes; they would look observationally almost like black holes but would have no horizon. The properties in the near-horizon region where gravity is strong can be quite different for both types of objects, but at infinity it could be difficult to discern black holes from their mimickers. To disentangle this possible confusion, we examine the near-horizon properties, and their connection with far away asymptotic properties, of some candidates to black mimickers. We study spherically symmetric uncharged or charged but nonextremal objects, as well as spherically symmetric charged extremal objects. Within the uncharged or charged but nonextremal black hole mimickers, we study nonextremal {epsilon}-wormholes on the threshold of the formation of an event horizon, of which a subclass are called black foils, and gravastars. Within the charged extremal black hole mimickers we study extremal {epsilon}-wormholes on the threshold of the formation of an event horizon, quasi-black holes, and wormholes on the basis of quasi-black holes from Bonnor stars. We elucidate whether or not the objects belonging to these two classes remain regular in the near-horizon limit. The requirement of full regularity, i.e., finite curvature and absence of naked behavior, up to an arbitrary neighborhood of the gravitational radius of the object enables one to rule out potential mimickers in most of the cases. A list ranking the best black hole mimickers up to the worst, both nonextremal and extremal, is as follows: wormholes on the basis of extremal black holes or on the basis of quasi-black holes, quasi-black holes, wormholes on the basis of nonextremal black holes (black foils), and gravastars. Since in observational astrophysics it is difficult to find extremal configurations (the best mimickers in the ranking), whereas nonextremal configurations are really bad mimickers, the task of distinguishing black holes from their mimickers seems to

  5. Pediatric myositis ossificans mimicking osteosarcoma.

    PubMed

    Yamaga, Kensaku; Kobayashi, Eisuke; Kubota, Daisuke; Setsu, Nokitaka; Tanaka, Yuya; Minami, Yusuke; Tanzawa, Yoshikazu; Nakatani, Fumihiko; Kawai, Akira; Chuman, Hirokazu

    2015-10-01

    Myositis ossificans (MO) is a rare benign cause of heterotopic bone formation in soft tissue that most commonly affects young adults, typically following trauma. We report the case of an 11-year-old girl who developed MO mimicking osteosarcoma in her right shoulder. Plain radiography and computed tomography showed poorly defined flocculated densities in the soft tissue and a periosteal reaction along the proximal humerus. On magnetic resonance imaging, the mass displayed an ill-defined margin and inhomogeneous signal change. Histologically, the mass had a pseudosarcomatous appearance. Based on these findings, the patient was initially misdiagnosed with osteosarcoma at another hospital. The diagnosis was difficult because the patient was 11 years old and had no trauma history, with atypical radiographic changes and a predilection for the site of origin for osteosarcomas. We finally made the correct diagnosis of MO by carefully reviewing and reflecting on the pathological differences between stages. © 2015 Japan Pediatric Society.

  6. Diseases mimicking intussusception: diagnostic dilemma.

    PubMed

    Karakus, Suleyman Cuneyt; Ozokutan, Bulent Hayri; Ceylan, Haluk

    2014-10-01

    Intussusception is a common abdominal emergency in early childhood. The aim of this study was to describe the diseases mimicking intussusception and to discuss the causes and management of these conditions. Seven patients who were initially diagnosed as having intussusception on abdominal ultrasonography but who had a final diagnosis of diseases other than intussusception were reviewed retrospectively. Two patients with ileocolic intussusception underwent ultrasonography-guided reduction with a hydrostatic method but the ultrasonographic findings persisted. At surgery, only edematous ileocecal valve and mesenteric lymphadenopathy were observed. In three patients with Henoch-Schönlein purpura, initial abdominal ultrasonography showed intussusception. The patients with no sign of obstructive symptoms were managed conservatively with a diagnosis of intramural hemorrhage and on follow up the ultrasonographic findings of intussusception was resolved. One patient with the target sign on computed tomography and ultrasonography of the abdomen underwent ileocolic resection and end-to-end anastomosis due to a tumor in the cecum. There was no evidence of intussusception. One patient with a cyst in the right lower quadrant accompanying intussusception on ultrasonography of the abdomen underwent ultrasonography-guided reduction but the ultrasonographic findings persisted. On exploration, only cecal duplication cyst without intussusception was detected. Cecal resection including the cyst and end-to-end ileocolic anastomosis were performed. Ultrasonography, color Doppler ultrasonography, barium or hydrostatic enema and computed tomography are helpful in diagnosing intussusception, but patients with radiologic findings of intussusception should be evaluated on symptoms and clinical findings before surgical intervention. Also, other diseases mimicking intussusception should be kept in mind in the differential diagnosis. © 2014 Japan Pediatric Society.

  7. Bone tumor mimickers: A pictorial essay

    PubMed Central

    Mhuircheartaigh, Jennifer Ni; Lin, Yu-Ching; Wu, Jim S

    2014-01-01

    Focal lesions in bone are very common and many of these lesions are not bone tumors. These bone tumor mimickers can include numerous normal anatomic variants and non-neoplastic processes. Many of these tumor mimickers can be left alone, while others can be due to a significant disease process. It is important for the radiologist and clinician to be aware of these bone tumor mimickers and understand the characteristic features which allow discrimination between them and true neoplasms in order to avoid unnecessary additional workup. Knowing which lesions to leave alone or which ones require workup can prevent misdiagnosis and reduce patient anxiety. PMID:25114385

  8. Scalene myofascial pain syndrome mimicking cervical disc prolapse: a report of two cases.

    PubMed

    Abd Jalil, Nizar; Awang, Mohammad Saufi; Omar, Mahamarowi

    2010-01-01

    Scalene myofascial pain syndrome is a regional pain syndrome wherein pain originates over the neck area and radiates down to the arm. This condition may present as primary or secondary to underlying cervical pathology. Although scalene myofascial pain syndrome is a well known medical entity, it is often misdiagnosed as being some other neck pain associated with radiculopathy, such as cervical disc prolapse, cervical spinal stenosis and thoracic outlet syndrome. Because scalene myofascial pain syndrome mimics cervical radiculopathy, this condition often leads to mismanagement, which can, in turn, result in persistent pain and suffering. In the worst-case scenarios, patients may be subjected to unjustifiable surgical intervention. Because the clinical findings in scalene myofascial pain syndrome are "pathognomonic", clinicians should be aware of ways to recognize this disorder and be able to differentiate it from other conditions that present with neck pain and rediculopathy. We present two cases of unilateral scalene myofascial pain syndrome that significantly impaired the patients' functioning and quality of life. This case report serves to create awareness about the existence of the syndrome and to highlight the potential morbidity due to clinical misdiagnosis.

  9. Developing ecological scenarios for the prospective aquatic risk assessment of pesticides.

    PubMed

    Rico, Andreu; Van den Brink, Paul J; Gylstra, Ronald; Focks, Andreas; Brock, Theo Cm

    2016-07-01

    The prospective aquatic environmental risk assessment (ERA) of pesticides is generally based on the comparison of predicted environmental concentrations in edge-of-field surface waters with regulatory acceptable concentrations derived from laboratory and/or model ecosystem experiments with aquatic organisms. New improvements in mechanistic effect modeling have allowed a better characterization of the ecological risks of pesticides through the incorporation of biological trait information and landscape parameters to assess individual, population and/or community-level effects and recovery. Similarly to exposure models, ecological models require scenarios that describe the environmental context in which they are applied. In this article, we propose a conceptual framework for the development of ecological scenarios that, when merged with exposure scenarios, will constitute environmental scenarios for prospective aquatic ERA. These "unified" environmental scenarios are defined as the combination of the biotic and abiotic parameters that are required to characterize exposure, (direct and indirect) effects, and recovery of aquatic nontarget species under realistic worst-case conditions. Ideally, environmental scenarios aim to avoid a potential mismatch between the parameter values and the spatial-temporal scales currently used in aquatic exposure and effect modeling. This requires a deeper understanding of the ecological entities we intend to protect, which can be preliminarily addressed by the formulation of ecological scenarios. In this article we present a methodological approach for the development of ecological scenarios and illustrate this approach by a case-study for Dutch agricultural ditches and the example focal species Sialis lutaria. Finally, we discuss the applicability of ecological scenarios in ERA and propose research needs and recommendations for their development and integration with exposure scenarios. Integr Environ Assess Manag 2016;12:510-521.

  10. Scenarios of large mammal loss in Europe for the 21st century.

    PubMed

    Rondinini, Carlo; Visconti, Piero

    2015-08-01

    Distributions and populations of large mammals are declining globally, leading to an increase in their extinction risk. We forecasted the distribution of extant European large mammals (17 carnivores and 10 ungulates) based on 2 Rio+20 scenarios of socioeconomic development: business as usual and reduced impact through changes in human consumption of natural resources. These scenarios are linked to scenarios of land-use change and climate change through the spatial allocation of land conversion up to 2050. We used a hierarchical framework to forecast the extent and distribution of mammal habitat based on species' habitat preferences (as described in the International Union for Conservation of Nature Red List database) within a suitable climatic space fitted to the species' current geographic range. We analyzed the geographic and taxonomic variation of habitat loss for large mammals and the potential effect of the reduced impact policy on loss mitigation. Averaging across scenarios, European large mammals were predicted to lose 10% of their habitat by 2050 (25% in the worst-case scenario). Predicted loss was much higher for species in northwestern Europe, where habitat is expected to be lost due to climate and land-use change. Change in human consumption patterns was predicted to substantially improve the conservation of habitat for European large mammals, but not enough to reduce extinction risk if species cannot adapt locally to climate change or disperse. © 2015 Society for Conservation Biology.

  11. Humanlike Robots - Synthetically Mimicking Humans

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    2012-01-01

    Nature inspired many inventions and the field of technology that is based on the mimicking or inspiration of nature is widely known as Biomimetics and it is increasingly leading to many new capabilities. There are numerous examples of biomimetic successes including the copying of fins for swimming, and the inspiration of the insects and birds flight. More and more commercial implementations of biomimetics are appearing and behaving lifelike and applications are emerging that are important to our daily life. Making humanlike robots is the ultimate challenge to biomimetics and, for many years, it was considered science fiction, but such robots are becoming an engineering reality. Advances in producing such robot are allowing them to perform impressive functions and tasks. The development of such robots involves addressing many challenges and is raising concerns that are related to fear of their application implications and potential ethical issues. In this paper, the state-of-the-art of humanlike robots, potential applications and challenges will be reviewed.

  12. Tracheobronchial Amyloidosis Mimicking Tracheal Tumor.

    PubMed

    Tanrıverdi, Elif; Özgül, Mehmet Akif; Uzun, Oğuz; Gül, Şule; Çörtük, Mustafa; Yaşar, Zehra; Acat, Murat; Arda, Naciye; Çetinkaya, Erdoğan

    2016-01-01

    Tracheobronchial amyloidosis is a rare presentation and accounts for about 1% of benign tumors in this area. The diagnosis of disease is delayed due to nonspecific pulmonary symptoms. Therapeutic approaches are required to control progressive pulmonary symptoms for most of the patients. Herein, we report a case of a 68-year-old man admitted with progressive dyspnea to our institution for further evaluation and management. He was initially diagnosed with and underwent management for bronchial asthma for two years but had persistent symptoms despite optimal medical therapy. Pulmonary computed tomography scan revealed severe endotracheal stenosis. Bronchoscopy was performed and showed endotracheal mass obstructing 70% of the distal trachea and mimicking a neoplastic lesion. The mass was successfully resected by mechanical resection, argon plasma coagulation (APC), and Nd-YAG laser during rigid bronchoscopy. Biopsy materials showed deposits of amorphous material by hematoxylin and eosin staining and these deposits were selectively stained with Congo Red. Although this is a rare clinical condition, this case indicated that carrying out a bronchoscopy in any patient complaining of atypical bronchial symptoms or with uncontrolled asthma is very important.

  13. Tracheobronchial Amyloidosis Mimicking Tracheal Tumor

    PubMed Central

    Özgül, Mehmet Akif; Uzun, Oğuz; Yaşar, Zehra; Acat, Murat; Arda, Naciye; Çetinkaya, Erdoğan

    2016-01-01

    Tracheobronchial amyloidosis is a rare presentation and accounts for about 1% of benign tumors in this area. The diagnosis of disease is delayed due to nonspecific pulmonary symptoms. Therapeutic approaches are required to control progressive pulmonary symptoms for most of the patients. Herein, we report a case of a 68-year-old man admitted with progressive dyspnea to our institution for further evaluation and management. He was initially diagnosed with and underwent management for bronchial asthma for two years but had persistent symptoms despite optimal medical therapy. Pulmonary computed tomography scan revealed severe endotracheal stenosis. Bronchoscopy was performed and showed endotracheal mass obstructing 70% of the distal trachea and mimicking a neoplastic lesion. The mass was successfully resected by mechanical resection, argon plasma coagulation (APC), and Nd-YAG laser during rigid bronchoscopy. Biopsy materials showed deposits of amorphous material by hematoxylin and eosin staining and these deposits were selectively stained with Congo Red. Although this is a rare clinical condition, this case indicated that carrying out a bronchoscopy in any patient complaining of atypical bronchial symptoms or with uncontrolled asthma is very important. PMID:27594885

  14. Humanlike Robots - Synthetically Mimicking Humans

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph

    2012-01-01

    Nature inspired many inventions and the field of technology that is based on the mimicking or inspiration of nature is widely known as Biomimetics and it is increasingly leading to many new capabilities. There are numerous examples of biomimetic successes including the copying of fins for swimming, and the inspiration of the insects and birds flight. More and more commercial implementations of biomimetics are appearing and behaving lifelike and applications are emerging that are important to our daily life. Making humanlike robots is the ultimate challenge to biomimetics and, for many years, it was considered science fiction, but such robots are becoming an engineering reality. Advances in producing such robot are allowing them to perform impressive functions and tasks. The development of such robots involves addressing many challenges and is raising concerns that are related to fear of their application implications and potential ethical issues. In this paper, the state-of-the-art of humanlike robots, potential applications and challenges will be reviewed.

  15. Fibrosing mediastinitis mimicking bronchogenic carcinoma

    PubMed Central

    Bayiz, Hulya; Mutluay, Neslihan; Koyuncu, Adem; Demirag, Funda; Dagli, Gulfidan; Berktas, Bahadir; Berkoglu, Mine

    2013-01-01

    Fibrosing mediastinitis is a rare but benign disorder characterized by an excessive fibrotic reaction in the mediastinum which can result in compromise of airways, great vessels, and other mediastinal structures. In this paper we presented a patient with fibrosing mediastinitis mimicking bronchogenic carcinoma. The patient was a 32-year-old diabetic male admitting with cough and hemoptysis. There was a right hilar mass and multiple mediastinal conglomerated lymph nodes on chest computed tomography. Positron emission tomography with computed tomography (PET/CT) scan demonstrated increased fluorodeoxyglucose (FDG) uptake at the right hilar mass lesion and mediastinal lymph nodes. Fiberoptic bronchoscopy showed mucosal distortion of right upper lobe. Pathologic examination of the mucosal biopsy revealed inflammation. Endobronchial ultrasound guided transbronchial needle and cervical mediastinoscopic lymph node biopsies were undiagnostic. Diagnostic thoracotomy confirmed the diagnosis fibrosing mediastinitis. Administration of six months of systemic corticosteroid and antituberculous therapy was not beneficial. In conclusion, despite being a rare clinical entity, fibrosing mediastinitis should be kept in mind in the differential diagnosis of mediastinal mass lesions of unknown etiology. The diagnosis is exceptionally difficult in the presence of atypical radiological findings. The treatment is particularly challenging without any proven effective therapy. PMID:23372962

  16. 33 CFR 154.1029 - Worst case discharge.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Response Plans for Oil Facilities § 154... from the pipe in hours, plus the maximum time to shut down flow from the pipe in hours (based on...) multiplied by the maximum flow rate expressed in barrels per hour (based on the maximum relief valve setting...

  17. 33 CFR 154.1029 - Worst case discharge.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Response Plans for Oil Facilities § 154... from the pipe in hours, plus the maximum time to shut down flow from the pipe in hours (based on...) multiplied by the maximum flow rate expressed in barrels per hour (based on the maximum relief valve setting...

  18. 33 CFR 154.1029 - Worst case discharge.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... facility. The discharge from each pipe is calculated as follows: The maximum time to discover the release from the pipe in hours, plus the maximum time to shut down flow from the pipe in hours (based on... or maximum system pressure when relief valves are not provided) plus the total line drainage volume...

  19. 49 CFR 194.105 - Worst case discharge.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: Prevention measure Standard Credit(percent) Secondary containment >100% NFPA 30 50 Built/repaired to API standards API STD 620/650/653 10 Overfill protection standards API RP 2350 5 Testing/cathodic protection API STD 650/651/653 5 Tertiary containment/drainage/treatment NFPA 30 5 Maximum allowable credit 75...

  20. 49 CFR 194.105 - Worst case discharge.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... secondary containment system, expressed in barrels (cubic meters). (4) Operators may claim prevention credits for breakout tank secondary containment and other specific spill prevention measures as follows... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY RESPONSE PLANS FOR ONSHORE OIL PIPELINES...

  1. 49 CFR 194.105 - Worst case discharge.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... secondary containment system, expressed in barrels (cubic meters). (4) Operators may claim prevention credits for breakout tank secondary containment and other specific spill prevention measures as follows... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY RESPONSE PLANS FOR ONSHORE OIL PIPELINES...

  2. 33 CFR 154.1029 - Worst case discharge.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... vessel regardless of the presence of secondary containment; plus (2) The discharge from all piping... historic discharge data or the best estimate in the absence of historic discharge data for the...

  3. 49 CFR 194.105 - Worst case discharge.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hours (based on historic discharge data or in the absence of such historic data, the operator's best... battery of tanks within a single secondary containment system, adjusted for the capacity or size of the secondary containment system, expressed in barrels (cubic meters). (4) Operators may claim...

  4. 33 CFR 154.1029 - Worst case discharge.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... operation of the pipelines used for the purposes of handling or transporting oil, in bulk, to or from a... in which the oil is stored or transported. ...) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Response Plans for Oil Facilities § 154...

  5. Inverse heat mimicking of given objects

    PubMed Central

    Alwakil, Ahmed; Zerrad, Myriam; Bellieud, Michel; Amra, Claude

    2017-01-01

    We address a general inverse mimicking problem in heat conduction. The objects to cloak and mimic are chosen beforehand; these objects identify a specific set of space transformations. The shapes that can be mimicked are derived from the conductivity matrices. Numerical calculation confirms all of the analytical predictions. The technique provides key advantages for applications and can be extended to the field of waves. PMID:28252031

  6. Simulation of X-38 Landing Scenarios With Landing Gear Failures

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Lyle, Karen H.; Pritchard, Jocelyn I.; Stockwell, Alan E.

    2000-01-01

    Abnormal landing scenarios of the X-38 prototype Crew Rescue Vehicle (CRV) were modeled for three different cases involving non-deployment of landing gear with an explicit dynamic nonlinear finite element code, MSC/DYTRAN. The goal of this research was to develop models to predict the probability of crew injuries. The initial velocity conditions for the X-38 with chute deployed were 10 ft/s vertical and 57 ft/s longitudinal velocity. An MSC/NASTRAN structural model was supplied by JSC and was converted to a dynamic MSC/DYTRAN model. The MSC/NASTRAN model did not include seats or floor structure; thus, the acceleration of a lumped-mass attached to the bulkhead near each assumed occupant location was used to determine injury risk for each occupant. The worst case for injury was nondeployment of all gears. The mildest case was nondeployment of one main gear. Although a probability for minor injury was predicted for all cases, it is expected that the addition of energy-absorbing floor structure and seats would greatly diminish the probability of injury.

  7. Natural Hazards Risk Reduction and the ARkStorm Scenario

    NASA Astrophysics Data System (ADS)

    Cox, D. A.; Dettinger, M. D.; Ralph, F. M.

    2016-12-01

    The ARkStorm Scenario project began in 2008, led by the USGS Multi-Hazards Demonstration Project (now Science Application for Risk Reduction) in an effort to innovate the application of science to reduce natural-hazard risk associated with large atmospheric-river (AR) storms on the West Coast of the US. The effort involved contributions from many federal, state and academic organizations including NOAA's Environmental Systems Laboratory. The ARkStorm project used new understanding of atmospheric river physics, combined with downscaled meteorological data from two recent ARs (in 1969 and 1986), to describe and model a prolonged sequence of back-to-back storms similar to those that bankrupted California in 1862. With this scientifically plausible (but not worst-case) scenario, the ARkStorm team engaged flood and levee experts to identify plausible flooding extents and durations, created a coastal-storm inundation model (CoSMoS), and California's first landslide susceptibility map, to better understand secondary meteorological and geophysical hazards (flood, wind, landslide, coastal erosion and inundation) across California. Physical damages to homes, infrastructure, agriculture, and the environment were then estimated to calculate the likely social and economic impact to California and the nation. Across California, property damage from the ARkStorm scenario was estimated to exceed 300 billion, mostly from flooding. Including damage and losses, lifeline damages and business interruptions, the total cost of an ARkStorm-sized series of storms came to nearly 725 billion, nearly three times the losses estimated from another SAFRR scenario describing a M7.8 earthquake in southern California. Thus, atmospheric rivers have the potential to be California's other "Big One." Since its creation, the ARkStorm scenario has been used in preparedness exercises by NASA, the US Navy, the State of California, the County of Ventura, and cities and counties in the Tahoe Basin and

  8. Recurrent epiploic appendagitis mimicking appendicitis and cholecystitis

    PubMed Central

    Hearne, Christopher B.; Taboada, Jorge

    2017-01-01

    Epiploic appendagitis (EA) is a rare cause of acute abdominal pain caused by inflammation of an epiploic appendage. It has a nonspecific clinical presentation that may mimic other acute abdominal pathologies on physical exam, such as appendicitis, diverticulitis, or cholecystitis. However, EA is usually benign and self-limiting and can be treated conservatively. We present the case of a patient with two episodes of EA, the first mimicking acute appendicitis and the second mimicking acute cholecystitis. Although recurrence of EA is rare, it should be part of the differential diagnosis of acute, localized abdominal pain. A correct diagnosis of EA will prevent unnecessary hospitalization, antibiotic use, and surgical procedures. PMID:28127129

  9. Tissue mimicking materials for dental ultrasound

    PubMed Central

    Singh, Rahul S.; Culjat, Martin O.; Grundfest, Warren S.; Brown, Elliott R.; White, Shane N.

    2008-01-01

    While acoustic tissue mimicking materials have been explored for a variety of soft and hard biological tissues, no dental hard tissue mimicking materials have been characterized. Tooth phantoms are necessary to better understand acoustic phenomenology within the tooth environment and to accelerate the advancement of dental ultrasound imaging systems. In this study, soda lime glass and dental composite were explored as surrogates for human enamel and dentin, respectively, in terms of compressional velocity, attenuation, and acoustic impedance. The results suggest that a tooth phantom consisting of glass and composite can effectively mimic the acoustic behavior of a natural human tooth. PMID:18396919

  10. Tissue mimicking materials for dental ultrasound.

    PubMed

    Singh, Rahul S; Culjat, Martin O; Grundfest, Warren S; Brown, Elliott R; White, Shane N

    2008-04-01

    While acoustic tissue mimicking materials have been explored for a variety of soft and hard biological tissues, no dental hard tissue mimicking materials have been characterized. Tooth phantoms are necessary to better understand acoustic phenomenology within the tooth environment and to accelerate the advancement of dental ultrasound imaging systems. In this study, soda lime glass and dental composite were explored as surrogates for human enamel and dentin, respectively, in terms of compressional velocity, attenuation, and acoustic impedance. The results suggest that a tooth phantom consisting of glass and composite can effectively mimic the acoustic behavior of a natural human tooth.

  11. Scenario-based radiation therapy margins for patient setup, organ motion, and particle range uncertainty

    NASA Astrophysics Data System (ADS)

    Bokrantz, Rasmus; Fredriksson, Albin

    2017-02-01

    This work extends and validates the scenario-based generalization of margins presented in Fredriksson and Bokrantz (2016 Phys. Med. Biol. 61 2067-82). Scenario-based margins are, in their original form, a method for robust planning under setup uncertainty where the sum of a plan evaluation criterion over a set of scenarios is optimized. The voxelwise penalties in the summands are weighted by a distribution of coefficients defined such that the method is mathematically equivalent to the use of conventional geometric margins if the scenario doses are calculated using the static dose cloud approximation. The purpose of this work is to extend scenario-based margins to general types of geometric uncertainty and to validate their use on clinical cases. Specifically, we outline how to incorporate density heterogeneity in the calculation of coefficients and demonstrate the extended method’s ability to safeguard against setup errors, organ motion, and range shifts (and combinations thereof). For a water phantom with a high-density slab partly covering the target, the extended form of scenario-based margins method led to improved target coverage robustness compared to the original method. At most minor differences in robustness were, however, observed between the extended and original method for a prostate and two lung patients, all treated with intensity-modulated proton therapy, yielding evidence that the calculation of weighting coefficients is generally insensitive to tissue heterogeneities. The scenario-based margins were, furthermore, verified to provide a comparable level of robustness to expected value and worst case optimization while circumventing some known shortcomings of these methods.

  12. Scenario-based radiation therapy margins for patient setup, organ motion, and particle range uncertainty.

    PubMed

    Bokrantz, Rasmus; Fredriksson, Albin

    2017-02-21

    This work extends and validates the scenario-based generalization of margins presented in Fredriksson and Bokrantz (2016 Phys. Med. Biol. 61 2067-82). Scenario-based margins are, in their original form, a method for robust planning under setup uncertainty where the sum of a plan evaluation criterion over a set of scenarios is optimized. The voxelwise penalties in the summands are weighted by a distribution of coefficients defined such that the method is mathematically equivalent to the use of conventional geometric margins if the scenario doses are calculated using the static dose cloud approximation. The purpose of this work is to extend scenario-based margins to general types of geometric uncertainty and to validate their use on clinical cases. Specifically, we outline how to incorporate density heterogeneity in the calculation of coefficients and demonstrate the extended method's ability to safeguard against setup errors, organ motion, and range shifts (and combinations thereof). For a water phantom with a high-density slab partly covering the target, the extended form of scenario-based margins method led to improved target coverage robustness compared to the original method. At most minor differences in robustness were, however, observed between the extended and original method for a prostate and two lung patients, all treated with intensity-modulated proton therapy, yielding evidence that the calculation of weighting coefficients is generally insensitive to tissue heterogeneities. The scenario-based margins were, furthermore, verified to provide a comparable level of robustness to expected value and worst case optimization while circumventing some known shortcomings of these methods.

  13. Systemic sarcoidosis mimicking malignant metastatic disease

    PubMed Central

    Hammen, Irena; Sherson, David Lee; Davidsen, Jesper Roemhild

    2015-01-01

    We present a case of systemic sarcoidosis involving the liver, pancreas, lungs, mediastinal and intraabdominal lymph nodes and bones. Multiple organ system manifestations mimicked malignant metastatic disease. The diagnosis was established with clinical, radiological, and pathological findings after neoplasm was ruled out by pathological tests. The patient showed rapid symptom remission with systemic steroid treatment. PMID:26672956

  14. Lymphomatoid granulomatosis mimicking interstitial lung disease.

    PubMed

    Braham, Emna; Ayadi-Kaddour, Aïda; Smati, Belhassen; Ben Mrad, Sonia; Besbes, Mohammed; El Mezni, Faouzi

    2008-11-01

    Lymphoid granulomatosis is a rare form of pulmonary angiitis. This case report presents a patient with lymphoid granulomatosis in whom the clinical presentation, radiological features and the partial response to corticosteroid therapy mimicked interstitial lung disease. Lymphoid granulomatosis was only diagnosed at post-mortem examination. The range of reported clinical presentations, diagnostic approaches and outcomes are described.

  15. Sensitivity of the global submarine hydrate inventory to scenarios of future climate change

    NASA Astrophysics Data System (ADS)

    Hunter, S. J.; Goldobin, D. S.; Haywood, A. M.; Ridgwell, A.; Rees, J. G.

    2013-04-01

    The global submarine inventory of methane hydrate is thought to be considerable. The stability of marine hydrates is sensitive to changes in temperature and pressure and once destabilised, hydrates release methane into sediments and ocean and potentially into the atmosphere, creating a positive feedback with climate change. Here we present results from a multi-model study investigating how the methane hydrate inventory dynamically responds to different scenarios of future climate and sea level change. The results indicate that a warming-induced reduction is dominant even when assuming rather extreme rates of sea level rise (up to 20 mm yr-1) under moderate warming scenarios (RCP 4.5). Over the next century modelled hydrate dissociation is focussed in the top ˜100m of Arctic and Subarctic sediments beneath <500m water depth. Predicted dissociation rates are particularly sensitive to the modelled vertical hydrate distribution within sediments. Under the worst case business-as-usual scenario (RCP 8.5), upper estimates of resulting global sea-floor methane fluxes could exceed estimates of natural global fluxes by 2100 (>30-50TgCH4yr-1), although subsequent oxidation in the water column could reduce peak atmospheric release rates to 0.75-1.4 Tg CH4 yr-1.

  16. Topical report on release scenario analysis of long-term management of high-level defense waste at the Hanford Site

    SciTech Connect

    Wallace, R.W.; Landstrom, D.K.; Blair, S.C.; Howes, B.W.; Robkin, M.A.; Benson, G.L.; Reisenauer, A.E.; Walters, W.H.; Zimmerman, M.G.

    1980-11-01

    Potential release scenarios for the defense high-level waste (HLW) on the Hanford Site are presented. Presented in this report are the three components necessary for evaluating the various alternatives under consideration for long-term management of Hanford defense HLW: identification of scenarios and events which might directly or indirectly disrupt radionuclide containment barriers; geotransport calculations of waste migration through the site media; and consequence (dose) analyses based on groundwater and air pathways calculations. The scenarios described in this report provide the necessary parameters for radionuclide transport and consequence analysis. Scenarios are categorized as either bounding or nonbounding. Bounding scenarios consider worst case or what if situations where an actual and significant release of waste material to the environment would happen if the scenario were to occur. Bounding scenarios include both near-term and long-term scenarios. Near-term scenarios are events which occur at 100 years from 1990. Long term scenarios are potential events considered to occur at 1000 and 10,000 years from 1990. Nonbounding scenarios consider events which result in insignificant releases or no release at all to the environment. Three release mechanisms are described in this report: (1) direct exposure of waste to the biosphere by a defined sequence of events (scenario) such as human intrusion by drilling; (2) radionuclides contacting an unconfined aquifer through downward percolation of groundwater or a rising water table; and (3) cataclysmic or explosive release of radionuclides by such mechanisms as meteorite impact, fire and explosion, criticality, or seismic events. Scenarios in this report present ways in which these release mechanisms could occur at a waste management facility. The scenarios are applied to the two in-tank waste management alternatives: in-situ disposal and continued present action.

  17. Scenario Based Approach for Multiple Source Tsunami Hazard Assessment for Sines, Portugal

    NASA Astrophysics Data System (ADS)

    Wronna, Martin; Omira, Rachid; Baptista, Maria Ana

    2015-04-01

    In this paper, we present a scenario-based approach for tsunami hazard assessment for the city and harbour of Sines, Portugal one the test-sites of project ASTARTE. Sines holds one of the most important deep-water ports which contains oil-bearing, petrochemical, liquid bulk, coal and container terminals. The port and its industrial infrastructures are facing the ocean to the southwest facing the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, a total of five scenarios were selected to assess tsunami impact at the test site. These scenarios correspond to the worst-case credible scenario approach based upon the largest events of the historical and paleo tsunami catalogues. The tsunami simulations from the source area towards the coast is carried out using NSWING a Non-linear Shallow Water Model With Nested Grids. The code solves the non-linear shallow water equations using the discretization and explicit leap-frog finite difference scheme, in a Cartesian or Spherical frame. The initial sea surface displacement is assumed to be equal to the sea bottom deformation that is computed by Okada equations. Both uniform and non-uniform slip conditions are used. The presented results correspond to the models using non-uniform slip conditions. In this study, the static effect of tides is analysed for three different tidal stages MLLW (mean lower low water) MSL (mean sea level) and MHHW (mean higher high water). For each scenario, inundation is described by maximum values of wave height, flow depth, drawdown, run-up and inundation distance. Synthetic waveforms are computed at virtual tide gages at specific locations outside and inside the harbour. The final results consist of Aggregate Scenario Maps presented for the different inundation parameters. This work is funded by ASTARTE - Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839

  18. Pesticide exposure assessment for surface waters in the EU. Part 2: Determination of statistically based run-off and drainage scenarios for Germany.

    PubMed

    Bach, Martin; Diesner, Mirjam; Großmann, Dietlinde; Guerniche, Djamal; Hommen, Udo; Klein, Michael; Kubiak, Roland; Müller, Alexandra; Preuss, Thomas G; Priegnitz, Jan; Reichenberger, Stefan; Thomas, Kai; Trapp, Matthias

    2017-05-01

    In order to assess surface water exposure to active substances of plant protection products (PPPs) in the European Union (EU), the FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) surface water workgroup introduced four run-off and six drainage scenarios for Step 3 of the tiered FOCUSsw approach. These scenarios may not necessarily represent realistic worst-case situations for the different Member States of the EU. Hence, the suitability of the scenarios for risk assessment in the national authorisation procedures is not known. Using Germany as an example, the paper illustrates how national soil-climate scenarios can be developed to model entries of active substances into surface waters from run-off and erosion (using the model PRZM) and from drainage (using the model MACRO). In the authorisation procedure for PPPs on Member State level, such soil-climate scenarios can be used to determine exposure endpoints with a defined overall percentile. The approach allows the development of national specific soil-climate scenarios and to calculate percentile-based exposure endpoints. The scenarios have been integrated into a software tool analogous to FOCUS-SWASH which can be used in the future to assess surface water exposure in authorisation procedures of PPPs in Germany. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  19. Nuclear Security Futures Scenarios.

    SciTech Connect

    Keller, Elizabeth James Kistin; Warren, Drake Edward; Hayden, Nancy Kay; Passell, Howard D.; Malczynski, Leonard A.; Backus, George A.

    2017-01-01

    This report provides an overview of the scenarios used in strategic futures workshops conducted at Sandia on September 21 and 29, 2016. The workshops, designed and facilitated by analysts in Center 100, used scenarios to enable thought leaders to think collectively about the changing aspects of global nuclear security and the potential implications for the US Government and Sandia National Laboratories.

  20. Intramedullary cervical neurenteric cyst mimicking an abscess.

    PubMed

    Muzumdar, D; Bhatt, Y; Sheth, J

    2008-01-01

    We describe a cervical intramedullary neurenteric cyst in a 12-year-old male patient who presented with gradual onset and progressively worsening neck pain, spastic quadriparesis and impaired sensation in the C(2) dermatome. MR imaging revealed a well-defined peripherally enhancing cystic intramedullary lesion with a posteroinferior enhancing nodule at the C(2)-C(3) level mimicking an abscess. There was no evidence of spinal dysraphism. The lesion was completely resected through a posterior approach and the patient showed radical improvement in his symptomatology. At follow-up after 3 years, he was asymptomatic and the MR imaging showed no evidence of any residual or recurrent cyst. The case presented here is unique, since a spinal neurenteric cyst showing intense peripheral contrast enhancement mimicking an abscess is unusual. The radiological features, pathogenesis and surgical considerations in cervical intramedullary neurenteric cysts are discussed and the relevant literature is briefly reviewed.

  1. Spherical boson stars as black hole mimickers

    SciTech Connect

    Guzman, F. S.; Rueda-Becerril, J. M.

    2009-10-15

    We present spherically symmetric boson stars as black hole mimickers based on the power spectrum of a simple accretion disk model. The free parameters of the boson star are the mass of the boson and the fourth-order self-interaction coefficient in the scalar field potential. We show that even if the mass of the boson is the only free parameter, it is possible to find a configuration that mimics the power spectrum of the disk due to a black hole of the same mass. We also show that for each value of the self-interaction a single boson star configuration can mimic a black hole at very different astrophysical scales in terms of the mass of the object and the accretion rate. In order to show that it is possible to distinguish one of our mimickers from a black hole, we also study the deflection of light.

  2. Pulmonary diseases with imaging findings mimicking aspergilloma.

    PubMed

    Gazzoni, Fernando Ferreira; Severo, Luiz Carlos; Marchiori, Edson; Guimarães, Marcos Duarte; Garcia, Tiago Severo; Irion, Klaus L; Camargo, José Jesus; Felicetti, José Carlos; de Mattos Oliveira, Flavio; Hochhegger, Bruno

    2014-06-01

    Patients with preexisting lung cavities are at risk of developing intracavitary fungal colonization. Because Aspergillus spp. are the most commonly implicated fungi, these fungal masses are called aspergillomas. Their characteristic "ball-in-hole" appearance, however, may be found in a variety of other conditions that can produce radiologic findings mimicking aspergilloma. In this paper, we review the main diseases that may mimic the radiographic findings of aspergilloma, with brief descriptions of clinical, radiologic, and histopathologic findings.

  3. Isolated giant molluscum contagiosum mimicking epidermoid cyst

    PubMed Central

    Uzuncakmak, Tugba K.; Kuru, Burce C.; Zemheri, Ebru I.; Zindanci, Ilkin; Turkoglu, Zafer; Kavala, Mukaddes

    2016-01-01

    Molluscum contagiosum is a benign cutaneous viral infection which is caused by double- stranded DNA poxvirus. It affects mainly children and young adults and usually presents with single or multiple umblicated papules or nodules on face, arms, legs and anogenital regions. It may present in atypical size and clinical appearance in patients with altered or impaired immunity and rarely in immuncompetent patients. Herein we present an immuncompetent young adult patient with isolated giant molluscum contagiosum, which was mimicking epidermoid cyst clinically. PMID:27648389

  4. Mad honey intoxication mimicking acute coronary syndrome.

    PubMed

    Dur, Ali; Sonmez, Ertan; Civelek, Cemil; AhmetTurkdogan, Kenan; AkifVatankulu, Mehmet; Sogut, Ozgur

    2014-09-01

    Mad honey intoxication or grayanotoxin poisoning is caused by consumption of grayanotoxin-containing toxic honey produced from leaves and flowers of the Rhododendron family. Despite the rarity of intoxication cases, the correct diagnosis and treatment are required because of the significance of haemodynamic disturbance and confounding of symptoms for disease identification. We report herein a case of a patient with mad honey intoxication mimicking acute non-ST segment elevation myocardial infarction and review the pathophysiology and diagnostic considerations.

  5. A Pilocytic Astrocytoma Mimicking a Clinoidal Meningioma

    PubMed Central

    Hong, Christopher S.; Lehman, Norman L.; Sauvageau, Eric

    2014-01-01

    Pilocytic astrocytomas and meningiomas are benign, primary brain tumors that may involve the optic tract. Classically, the presence of a dural “tail” sign may differentiate a meningioma from other intracranial lesions. In this report, we describe a mass with the typical appearance of a clinoidal meningioma on magnetic resonance imaging (MRI) but postoperatively diagnosed as a pilocytic astrocytoma. This case illustrates the rare occurrence of a pilocytic astrocytoma mimicking a meningioma on MRI. PMID:24744944

  6. Rare Mimickers of Exostosis: A Case Series

    PubMed Central

    Perubhotla, Lakshmi Manasa

    2016-01-01

    Exophytic growths from bones are a common entity. Osteochondroma is the most common benign exophytic lesion and we tend to diagnose every benign looking exophytic lesion as osteochondroma. Here we reported two entities of cases, one was Nora’s lesion and another one was supracondylar process of humerus, both of which were mimickers of osteochondroma and their salient and differentiating features from osteochondromas. PMID:27630926

  7. Exposure scenarios for workers.

    PubMed

    Marquart, Hans; Northage, Christine; Money, Chris

    2007-12-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate considerations of both human health and the environment. Specific aspects are relevant for worker exposure. Gathering information on the uses of the chemical is an important step in developing an Exposure Scenario. In-house information at manufacturers is an important source. Downstream users can contribute information through direct contact or through their associations. Relatively simple approaches (Tier 1 tools, such as the ECETOC Targeted Risk Assessment and the model EASE) can be used to develop broad Exposure Scenarios that cover many use situations. These approaches rely on the categorisation of just a few determinants, including only a small number of risk management measures. Such approaches have a limited discriminatory power and are rather conservative. When the hazard of the substance or the complexity of the exposure situation require a more in-depth approach, further development of the Exposure Scenarios with Tier 2 approaches is needed. Measured data sets of worker exposure are very valuable in a Tier 2 approach. Some downstream user associations have attempted to build Exposure Scenarios based on measured data sets. Generic Tier 2 tools for developing Exposure Scenarios do not exist yet. To enable efficient development of the worker exposure part of Exposure Scenarios a further development of Tier 1 and Tier 2 tools is needed. Special attention should be given to user friendliness and to the validity (boundaries) of the approaches. The development of standard worker exposure descriptions or full Exposure Scenarios by downstream user branches in cooperation with manufacturers and importers is recommended.

  8. Mars base buildup scenarios

    SciTech Connect

    Blacic, J.D.

    1985-01-01

    Two surface base build-up scenarios are presented in order to help visualize the mission and to serve as a basis for trade studies. In the first scenario, direct manned landings on the Martian surface occur early in the missions and scientific investigation is the main driver and rationale. In the second scenario, early development of an infrastructure to exploite the volatile resources of the Martian moons for economic purposes is emphasized. Scientific exploration of the surface is delayed at first, but once begun develops rapidly aided by the presence of a permanently manned orbital station.

  9. Handheld X-ray Fluorescence Spectrometers: Radiation Exposure Risks of Matrix-Specific Measurement Scenarios.

    PubMed

    Rouillon, Marek; Kristensen, Louise J; Gore, Damian B

    2015-07-01

    This study investigates X-ray intensity and dispersion around handheld X-ray fluorescence (XRF) instruments during the measurement of a range of sample matrices to establish radiation exposure risk during operation. Four handheld XRF instruments representing three manufacturers were used on four smooth, flat-lying materials of contrasting matrix composition. Dose rates were measured at 10, 20, 30, and 40 cm intervals every 30° around the instrument at 0 and 45° from the horizontal, as well as vertically from the instrument screen. The analysis of polyethylene recorded dose rates 156 times higher (on average) than steel measurements and 34 times higher than both quartz sand and quartz sandstone. A worst-case exposure scenario was assumed where a user analyses a polyethylene material at arms reach for 1 h each working day for one year. This scenario resulted in an effective body dose of 73.5 μSv, equivalent to three to four chest X-rays (20 μSv) a year, 20 times lower than the average annual background radiation exposure in Australia and well below the annual exposure limit of 1 mSv for non-radiation workers. This study finds the advantages of using handheld XRF spectrometers far outweighs the risk of low radiation exposure linked to X-ray scattering from samples.

  10. GLOBAL ALTERNATIVE FUTURE SCENARIOS

    EPA Science Inventory

    One way to examine possible future outcomes for environmental protection is through the development and analysis of alternative future scenarios. This type of assessment postulates two or more different paths that social and environmental development might take, using correspond...

  11. Emission scenarios: Explaining differences

    NASA Astrophysics Data System (ADS)

    Iyer, Gokul; Edmonds, James

    2017-01-01

    Carbon dioxide emission scenarios rely on a number of assumptions about how societies will develop in the future, creating uncertainty in projections. Now, research reveals the sensitivity of emission estimates to some of these assumptions.

  12. Retroperitoneal Cystic Malignant Fibrous Histiocytoma Mimicking a Psoas Abscess

    PubMed Central

    Gupta, Madan Mohan; Bahri, Nandini; Watal, Pankaj; Rathod, Ketan; Thaker, Siddarth; Bhandari, Parthiv; Dhamecha, Ketul; Ajudia, Jasmin

    2015-01-01

    Primary neoplasms in the psoas muscle including schwannoma and soft tissue sarcoma with secondary cystic degeneration are rare entities. They are difficult to distinguish from psoas abscess purely based on radiological findings. Malignant fibrous histiocytoma (MFH) in the retroperitoneum is an uncommon entity in contrast to liposarcoma and leiomyosarcoma. Psoas abscess is a common infection in the retroperitoneum, especially in regions where tuberculosis is endemic. In the current case, the patient presented with gradually progressive lower abdominal pain and raised erythrocyte sedimentation rate (ESR), lymphocyte count and sputum positive for acid fast bacilli. There was a presence of previous history of skeletal tuberculosis. Imaging revealed well-defined multilocular cystic lesion involving the left psoas muscle which along with the clinical scenario suggested psoas abscess. However, post-operative biopsy showed the lesion to be a MFH with extensive cystic degeneration. To the best of our knowledge, cystic MFH mimicking an abscess has been previously reported only once in an oncology literature. PMID:26557275

  13. Analysis of Glenoid Fixation with Anatomic Total Shoulder Arthroplasty in an Extreme Cyclic Loading Scenario.

    PubMed

    Roche, Christopher P; Staunch, Cameron; Hahn, William; Grey, Sean G; Flurin, Pierre-Henri; Wright, Thomas W; Zuckerman, Joseph D

    2015-12-01

    ASTM F2028-14 was adopted to recom mend a cyclic eccentric glenoid edge loading test that simulates the rocking horse loading mechanism beleived to cause aTSA glenoid loosening. While this method accurately simulates that failure mechanism, the recommended 750 N load may not be sufficient to simulate worst-case loading magnitudes, and the recommended 100,000 cycles may not be sufficient to simulate device fatigue-related failure modes. Finally, if greater loading magnitude or a larger number of cycles is performed, the recommended substrate density may not be sufficiently strong to support the elevated loads and cycles. To this end, a new test method is proposed to supplement ASTM F2028-14. A series of cyclic tests were performed to evaluate the long-term fixation strength of two different hybrid glenoid designs in both low (15 pcf) and high (30 pcf) density polyurethane blocks at elevated loads relative to ASTM F2028-14. To simulate a worst case clinical condition in which the humeral head is superiorly migrated, a cyclic load was applied to the superior glenoid rim to induce a maximum torque on the fixation pegs for three different cyclic loading tests: 1. 1,250 N load for 0.75 M cycles in a 15 pcf block, 2. 1,250 N load for 1.5 M cycles in a 30 pcf block, and 3. 2,000 N load for 0.65 M cycles in a 30 pcf block. All devices completed cyclic loading without failure, fracture, or loss of fixation regardless of glenoid design, polyurethane density, loading magnitude, or cycle length. No significant difference in post-cyclic displacement was noted between designs in any of the three tests. Post-cyclic radiographs demonstrated that each device maintained fixa - tion with the metal pegs within the bone-substitute blocks with no fatigue related failures. These results demonstrate that both cemented hybrid glenoids maintained fixation when tested according to each cyclic loading scenario, with no difference in post-cyclic displacement observed between designs. The lack

  14. Nontuberculous mycobacterial pulmonary disease mimicking lung cancer

    PubMed Central

    Hong, Su Jin; Kim, Tae Jung; Lee, Jae-Ho; Park, Jeong-Soo

    2016-01-01

    Abstract To describe the features and clinical implications of computed tomography (CT), positron emission tomography (PET), and percutaneous needle aspiration biopsy (PCNB) in pulmonary nontuberculous mycobacterial (NTM) disease manifesting as a solitary nodule, mass, or mass-like consolidation mimicking malignancy. Among a cohort of 388 patients with NTM pulmonary disease, 14 patients with clinically and radiologically suspected lung cancer were included in our study. Two chest radiologists evaluated CT features, including lesion type (nodule, mass, or mass-like consolidation), morphologic features (margin, degree of enhancement, calcification), and presence of accompanying findings suggestive of NTM pulmonary disease (bronchiectasis with clustered centrilobular nodules or upper-lobe cavitary lesions) by consensus. Diagnostic procedures for microbiologic diagnosis of NTM disease and clinical outcome were reviewed. Incidence of NTM pulmonary disease presenting as solitary nodule/mass (n = 8) or mass-like consolidation (n = 6) was 3.6% (14 of 388). Most lesions were detected incidentally during routine health check-up or evaluation of other disease (11 of 14, 79%). Lesions typically showed poor contrast-enhancement (9 of 12) and internal calcification (6 of 14). No lesions had CT features suggestive of NTM pulmonary disease. All 4 lesions for which PET/CT imaging was performed showed strong fluorodeoxyglucose uptake simulating malignant lesions (mean, 4.9; range, 3.6–7.8). PCNB revealed mycobacterial histology in 6 of 11 specimens and positive culture results were obtained for 7 of 7 specimens. NTM pulmonary disease may present as a solitary nodule, mass, or mass-like consolidation mimicking malignancy. CT features and PCNB are important to diagnose NTM disease mimicking lung cancer to avoid unnecessary surgery. PMID:27367996

  15. Brucellosis in spondyloarthritis mimicking an exacerbation.

    PubMed

    Garip, Y; Eser, F; Erten, S; Yilmaz, O; Yildirim, P

    2014-01-01

    Spondyloarthritis are a group of chronic inflammatory diseases that affect the axial skeleton, entheses and peripheral joints and may have extraarticular manifestations such as uveitis, psoriasis and inflammatory bowel disease. Brucellosis is a systemic infectious disease, endemic in Middle East, Latin America, and Mediterranean countries, which may present manifestations that resemble other diseases posing serious problems of differential diagnosis. Some hallmarks of Brucellosis may mimic a spondyloarthritis flare. In this paper, authors present a clinical case of brucellosis occurring in a patient with spondyloarthritis. Clinical symptoms initially mimicked exacerbation of spondyloarthritis.

  16. Thymic Langerhans cell histiocytosis mimicking lymphoma.

    PubMed

    Yağci, Begül; Varan, Ali; Uner, Aysegül; Akyüz, Canan; Büyükpamukçu, Münevver

    2008-12-01

    Langerhans cell histiocytosis (LCH) is a rare disorder characterized by clonal expansion of antigen presenting Langerhans cells. Different clinical features can be seen according to the involved organs and systems. Multisystem disease with organ dysfunction is more common in infants, whereas single system disease is usually observed in older children. The disease can affect any system or organ throughout the body. Thymus is a rarely involvement site reported in LCH and usually is accompanied by skin, bone or lung disease. Here we report a 12-year-old male with thymic involvement by LCH clinically mimicking lymphoma.

  17. Post-pancreatitis Fat Necrosis Mimicking Carcinomatosis.

    PubMed

    Smith, Joshua P; Arnoletti, J Pablo; Varadarajulu, Shyam; Morgan, Desiree E

    2008-01-01

    Acute pancreatitis can result in retroperitoneal fat necrosis, typically occurring in the peripancreatic region, with extension into the transverse mesocolon, omentum and mesenteric root. When evaluated with contrast enhanced computed tomography (CECT), acute peripancreatic post necrotic collections typically become lower in attenuation over time, and often appear as homogeneous fluid collections. Saponification as a complication of fat necrosis in patients with acute pancreatitis is a well recognized clinical entity. While retroperitonal fat necrosis is commonly seen on CECT, saponification is not a prominent imaging feature. We present a case of acute pancreatitis complicated by extensive saponification of fat throughout the retroperitoneum and peritoneal lining, mimicking carcinomatosis.

  18. Severe emphysematous pyelonephritis mimicking intestinal obstruction.

    PubMed

    Sun, Ji Ning; Zhang, Bao Long; Yu, Hai Yan; Wang, Bin

    2015-12-01

    Emphysematous pyelonephritis is a severe necrotizing infection characterized by the presence of gas and/or fluid in the renal parenchyma, collecting system, or perirenal tissues. Emphysematous pyelonephritis with approximately 15 cm air-fluid level, diffused ureteral involvement, and the accumulation of gas in liver and peritoneal cavity is very rare. Here, we reported a severe emphysematous pyelonephritis with multiple huge air-fluid level mimicking intestinal obstruction and with the accumulation of gas in liver and ureter in computed tomography imaging. The patient was successfully managed by percutaneous nephrostomy combined with medical treatment.

  19. Chondroblastoma of the acromion mimicking fibrous dysplasia.

    PubMed

    Gebert, Carsten; Hardes, Jendrik; Streitbürger, Arne; Vieth, Volker; Bürger, Horst; Winkelmann, Winfried; Gosheger, Georg

    2004-12-01

    The authors report the case of a 65-year-old man who presented with an expansive osteolytic lesion in the right acromion, mimicking cystic fibrous dysplasia. Magnetic resonance imaging showed a lesion with intermediate-signal intensity on T1-weighted images and a high-signal intensity on fat suppressed T2-weighted images. The biopsy led to the diagnosis of chondroblastoma. This tumour is rare in flat bones, and may mimic other benign or malignant lesions. It is therefore essential to perform a biopsy in order to obtain a definite diagnosis. The acromion was excised, and replaced with an iliac crest graft.

  20. Intradural Extramedullary Tuberculoma Mimicking En Plaque Meningioma

    PubMed Central

    Shim, Dae Moo; Kim, Tae Kyun; Chae, Soo Uk

    2010-01-01

    A 24-year-old man with tuberculosis meningitis developed acute paraplegia and sensory disturbances 5 weeks after receiving conventional antituberculous therapy. Magnetic resonance imaging revealed an intradural extramedullary long segmental mass mimicking en plaque meningioma at the T2-T6 vertebrae levels. Prompt surgical decompression was performed. A histology examination of the mass revealed a tuberculoma. After surgery, the patient showed improved motor power and a normal bladder function. Intradural extramedullary tuberculoma of the spinal cord is rare complication of tuberculosis meningitis, which can occur as a response to conventional antituberculous therapy. PMID:21119945

  1. Pulmonary tumour microembolism clinically mimicking alveolitis

    PubMed Central

    Lo, A W I; Tse, G M K; Chu, W C W; Chan, A B W

    2003-01-01

    A 56 year old man with previously unsuspected recurrence of squamous cell carcinoma of the oesophagus presented with dyspnoea. Bronchoscopy and computed tomography suggested bronchopneumonic changes with an infectious cause. He suffered a rapidly deteriorating course and died despite active treatment, including antibiotics and mechanical ventilation. Necropsy revealed a florid pulmonary tumour microembolism mimicking alveolitis. No bronchopneumonia was seen. The emboli arose from loosely attached tumour vegetations in the tricuspid valve. In a patient with known malignancy, tumour microembolism should be considered as an uncommon cause of rapid respiratory failure, refractory to antibiotic treatment. PMID:14600135

  2. Scenarios for gluino coannihilation

    SciTech Connect

    Ellis, John; Evans, Jason L.; Luo, Feng; Olive, Keith A.

    2016-02-11

    In this article, we study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parameter space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in particular, as well as the appearance of other dark matter (co)annihilation processes. Nevertheless, LSP masses mX ≲ 8TeV with the correct dark matter density are quite possible. In the case of pure gravity mediation with additional vector-like supermultiplets, changes to the anomaly-mediated gluino mass and the threshold effects associated with these states can make the gluino almost degenerate with the LSP, and we find a similar upper bound.

  3. Scenarios for gluino coannihilation

    DOE PAGES

    Ellis, John; Evans, Jason L.; Luo, Feng; ...

    2016-02-11

    In this article, we study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parametermore » space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in particular, as well as the appearance of other dark matter (co)annihilation processes. Nevertheless, LSP masses mX ≲ 8TeV with the correct dark matter density are quite possible. In the case of pure gravity mediation with additional vector-like supermultiplets, changes to the anomaly-mediated gluino mass and the threshold effects associated with these states can make the gluino almost degenerate with the LSP, and we find a similar upper bound.« less

  4. Attractive scenario writing.

    PubMed

    Takahashi, Yuzo; Oku, Sachiko Alexandra

    2009-05-01

    This article describes the key steps of scenario writing to facilitate problem-based learning discussion to aid student learning of basic medical science in combination with clinical medicine. The scenario has to amplify and deepen the students' thinking so that they can correlate findings from the case and knowledge from textbooks. This can be achieved in three ways: (1) a comparison of cases; (2) demonstrating a scientific link between symptoms and basic medicine; and (3) introducing a personal and emotional aspect to the scenario. A comparison of two cases enables us to shed light on the pathological differences and think about the underlying biological mechanisms. These include: (a) a comparison of two cases with similar symptoms, but different diseases; (b) a comparison of two cases with different symptoms, but the same cause; and (c) a comparison of two cases, with an easy case, followed by a complicated case. The scenarios may be disclosed in a sequence to show a scientific link between symptoms of the patient and basic medicine, which may help to cultivate a physician with a scientific mind. Examples are given by the relationship between: (a) symptoms, pathology and morphology; and (b) symptoms, pathology and physiology. When the scenario is written in such a way that students are personally and/or emotionally involved in the case, they will be more motivated in learning as if involved in the case themselves. To facilitate this, the scenario can be written in the first-person perspective. Examples include "I had a very bad headache, and vomited several times...", and "I noticed that my father was screaming at night...". The description of the events may be in chronological order with actual time, which makes students feel as if they are really the primary responding person.

  5. Clinical and Histologic Mimickers of Celiac Disease.

    PubMed

    Kamboj, Amrit K; Oxentenko, Amy S

    2017-08-17

    Celiac disease is an autoimmune disorder of the small bowel, classically associated with diarrhea, abdominal pain, and malabsorption. The diagnosis of celiac disease is made when there are compatible clinical features, supportive serologic markers, representative histology from the small bowel, and response to a gluten-free diet. Histologic findings associated with celiac disease include intraepithelial lymphocytosis, crypt hyperplasia, villous atrophy, and a chronic inflammatory cell infiltrate in the lamina propria. It is important to recognize and diagnose celiac disease, as strict adherence to a gluten-free diet can lead to resolution of clinical and histologic manifestations of the disease. However, many other entities can present with clinical and/or histologic features of celiac disease. In this review article, we highlight key clinical and histologic mimickers of celiac disease. The evaluation of a patient with serologically negative enteropathy necessitates a carefully elicited history and detailed review by a pathologist. Medications can mimic celiac disease and should be considered in all patients with a serologically negative enteropathy. Many mimickers of celiac disease have clues to the underlying diagnosis, and many have a targeted therapy. It is necessary to provide patients with a correct diagnosis rather than subject them to a lifetime of an unnecessary gluten-free diet.

  6. Doxycycline-induced ulceration mimicking esophageal cancer

    PubMed Central

    Tahan, Veysel; Sayrak, Hakan; Bayar, Nevzat; Erer, Burak; Tahan, Gulgun; Dane, Faysal

    2008-01-01

    Introduction Doxycycline-induced esophageal ulcer patients are mostly young persons with no history of esophageal dysfunction. Heartburn, midsternal pain and dysphagia are the most common symptoms. It has generally a benign course. The present case is the first report of doxycycline-induced extensive ulcerations, mimicking esophageal cancer in two esophageal segments alongside, in the literature. Case presentation This report describes a 16-year-old Caucasian girl who, while taking doxycycline capsules100 mg twice a day for acne vulgaris for 3 months, developed these symptoms. An upper endoscopy revealed multiple circumferential deep ulcerations surrounding fragile, irregular, hyperemic and hypertrophic mucosa at the level of the mid-esophagus and concomitantly in the lower esophageal sphincter. The lesions were biopsied to exclude esophageal carcinoma because of the suspicious appearance in the endoscopic examination. The histopathological examination, haematoxylin and eosin stained sections showed ulceration with a mixed inflammatory infiltrate. Doxycycline was discontinued and she was given sucralfate 1 g qid and omeprazole 20 mg bid orally. All symptoms of the patient were resolved on the third day of the treatment. After 4 weeks of the therapy, an upper endoscopic control examination demonstrated normal findings. Conclusion The present case has been an uncommon presentation of doxycycline-induced extensive ulcerations, mimicking esophageal cancer in two esophageal segments, concomitantly. Even the lesions were biopsied to exclude esophageal carcinoma. A modification on the behavior of taking drugs can prevent these unpleasant complications. PMID:18778470

  7. Inflammatory Myofibroblastic Tumor Mimicking Apical Periodontitis.

    PubMed

    Adachi, Makoto; Kiho, Kazuki; Sekine, Genta; Ohta, Takahisa; Matsubara, Makoto; Yoshida, Takakazu; Katsumata, Akitoshi; Tanuma, Jun-ichi; Sumitomo, Shinichiro

    2015-12-01

    Inflammatory myofibroblastic tumors (IMTs) are rare. IMTs of the head and neck occur in all age groups, from neonates to old age, with the highest incidence occurring in childhood and early adulthood. An IMT has been defined as a histologically distinctive lesion of uncertain behavior. This article describes an unusual case of IMT mimicking apical periodontitis in the mandible of a 42-year-old man. At first presentation, the patient showed spontaneous pain and percussion pain at teeth #28 to 30, which continued after initial endodontic treatment. Panoramic radiography revealed a radiolucent lesion at the site. Cone-beam computed tomographic imaging showed osteolytic lesions, suggesting an aggressive neoplasm requiring incisional biopsy. Histopathological examination indicated an IMT. The lesion was removed en bloc under general anesthesia, and the patient manifested no clinical evidence of recurrence for 24 months. Lesions of nonendodontic origin should be included in the differential diagnosis of apical periodontitis. Every available diagnostic tool should be used to confirm the diagnosis. Cone-beam computed tomographic imaging is very helpful for differential diagnosis in IMTs mimicking apical periodontitis.

  8. Nonlinearity parameter for tissue-mimicking materials.

    PubMed

    Dong, F; Madsen, E L; MacDonald, M C; Zagzebski, J A

    1999-06-01

    A finite amplitude insert-substitution method has been used to determine the ultrasonic nonlinearity parameter B/A of nine versions of water-based, macroscopically uniform ultrasonically tissue-mimicking (TM) nonfat and fat materials. In this method, the amplitude of the second harmonic following transmission through degassed distilled water with known B/A (B/A = 5.2) and the amplitude of the second harmonic following transmission through the unknown sample are measured. The ratio of these amplitudes allows calculation of the B/A of the sample. Measured B/A values of the nonfat materials range from 5.6 to 6.6. These values compare favorably with published values for nonfat soft tissues. In contrast, the measured B/A values for two tissue-mimicking fat materials are 9.8 and 11.1; these two values represent the low and high end of B/A for most fresh fatty tissues. For comparison, B/A was measured for two commonly available uniform materials, corn oil and ethylene glycol, and the results are in good agreement with published values.

  9. Engineering and environmental remediation scenarios due to leakage from the Gulf War oil spill using 3-D numerical contaminant modellings

    NASA Astrophysics Data System (ADS)

    Yihdego, Yohannes; Al-Weshah, Radwan A.

    2016-12-01

    The transport groundwater modelling has been undertaken to assess potential remediation scenarios and provide an optimal remediation options for consideration. The purpose of the study was to allow 50 years of predictive remediation simulation time. The results depict the likely total petroleum hydrocarbon migration pattern in the area under the worst-case scenario. The remediation scenario simulations indicate that do nothing approach will likely not achieve the target water quality within 50 years. Similarly, complete source removal approach will also likely not achieve the target water quality within 50 years. Partial source removal could be expected to remove a significant portion of the contaminant mass, but would increase the rate of contaminant recharge in the short to medium term. The pump-treat-reinject simulation indicates that the option appears feasible and could achieve a reduction in the area of the 0.01 mg/L TPH contour area for both Raudhatain and Umm Al-Aish by 35 and 30%, respectively, within 50 years. The rate of improvement and the completion date would depend on a range of factors such as bore field arrangements, pumping rates, reinjection water quality and additional volumes being introduced and require further optimisation and field pilot trials.

  10. Estimation of human damage and economic loss of buildings for the worst-credible scenario of tsunami inundation in the city of Augusta, Italy

    NASA Astrophysics Data System (ADS)

    Pagnoni, Gianluca; Tinti, Stefano

    2017-04-01

    The city of Augusta is located in the southern part of the eastern coast of Sicily. Italian tsunami catalogue and paleo-tsunami surveys indicate that at least 7 events of tsunami affected the bay of Augusta in the last 4,000 years, two of which are associated with earthquakes (1169 and 1693) that destroyed the city. For these reasons Augusta has been chosen in the project ASTARTE as a test site for the study of issues related to tsunami hazard and risk. In last two years we studied hazard through the approach of the worst-case credible scenario and carried out vulnerability and damage analysis for buildings. In this work, we integrate that research, and estimate the damage to people and the economic loss of buildings due to structural damage. As regards inundation, we assume both uniform inundation levels (bath-tub hypothesis) and inundation data resulting from the worst-case scenario elaborated for the area by Armigliato et al. (2015). Human damage is calculated in three steps using the method introduced by Pagnoni et al. (2016) following the work by Terrier et al. (2012) and by Koshimura et al. (2009). First, we use census data to estimate the number of people present in each residential building affected by inundation; second, based on water column depth and building type, we evaluate the level of damage to people; third, we provide an estimate of fatalities. The economic loss is computed for two types of buildings (residential and trade-industrial) by using data on inundation and data from the real estate market. This study was funded by the EU Project ASTARTE - "Assessment, STrategy And Risk Reduction for Tsunamis in Europe", Grant 603839, 7th FP (ENV.2013.6.4-3)

  11. The SAFRR Tsunami Scenario

    USGS Publications Warehouse

    Porter, K.; Jones, Lucile M.; Ross, Stephanie L.; Borrero, J.; Bwarie, J.; Dykstra, D.; Geist, Eric L.; Johnson, L.; Kirby, Stephen H.; Long, K.; Lynett, P.; Miller, K.; Mortensen, Carl E.; Perry, S.; Plumlee, G.; Real, C.; Ritchie, L.; Scawthorn, C.; Thio, H.K.; Wein, Anne; Whitmore, P.; Wilson, R.; Wood, Nathan J.; Ostbo, Bruce I.; Oates, Don

    2013-01-01

    The U.S. Geological Survey and several partners operate a program called Science Application for Risk Reduction (SAFRR) that produces (among other things) emergency planning scenarios for natural disasters. The scenarios show how science can be used to enhance community resiliency. The SAFRR Tsunami Scenario describes potential impacts of a hypothetical, but realistic, tsunami affecting California (as well as the west coast of the United States, Alaska, and Hawaii) for the purpose of informing planning and mitigation decisions by a variety of stakeholders. The scenario begins with an Mw 9.1 earthquake off the Alaska Peninsula. With Pacific basin-wide modeling, we estimate up to 5m waves and 10 m/sec currents would strike California 5 hours later. In marinas and harbors, 13,000 small boats are damaged or sunk (1 in 3) at a cost of $350 million, causing navigation and environmental problems. Damage in the Ports of Los Angeles and Long Beach amount to $110 million, half of it water damage to vehicles and containerized cargo. Flooding of coastal communities affects 1800 city blocks, resulting in $640 million in damage. The tsunami damages 12 bridge abutments and 16 lane-miles of coastal roadway, costing $85 million to repair. Fire and business interruption losses will substantially add to direct losses. Flooding affects 170,000 residents and workers. A wide range of environmental impacts could occur. An extensive public education and outreach program is underway, as well as an evaluation of the overall effort.

  12. Biomass Scenario Model

    SciTech Connect

    2015-09-01

    The Biomass Scenario Model (BSM) is a unique, carefully validated, state-of-the-art dynamic model of the domestic biofuels supply chain which explicitly focuses on policy issues, their feasibility, and potential side effects. It integrates resource availability, physical/technological/economic constraints, behavior, and policy. The model uses a system dynamics simulation (not optimization) to model dynamic interactions across the supply chain.

  13. Characterization of maritime scenarios

    NASA Astrophysics Data System (ADS)

    Low, Tom B.; Hudak, D. R.

    1992-09-01

    Meteorological modules were developed to describe characteristic maritime scenarios in various oceanic areas for DREV complimentarity studies of shipboard defense. The best means of depicting the maritime atmospheric environment was found to be on the basis of air mass analysis. A methodology was developed whereby, through a mixture of man-machine objective analysis of upper air radiosonde measurements at the 850, 700, and 500 mb levels, typical airmasses could be identified. Characteristic scenarios were then defined based on physical considerations of air mass theory. Utilizing an extensive 10-year set of worldwide radiosonde, ozondesonde, and surface observations collected from a combination of land-based stations, oceanographic buoys, and weather ships, frequency and correlation statistics of various global and derived meteorological and oceanographic parameters were established for the CANLANT, NORLANT, WESTLANT, EASTLANT, IBERLANT, MARPAC regions, the ARCTIC OCEAN to 85 degree(s)N, the BALTIC SEA, MEDITERRANEAN SEA, PERSIAN GULF, RED SEA, GULF OF OMAN, and the INDIAN OCEAN. These descriptions included atmospheric profiles of pressure, temperature, dewpoint and relative humidity, wind speeds and direction, refractivity index, and ozone concentration from the surface to approximately 20 km., as well as associated surface visibility, clouds and weather, sea state, and duct height conditions. Many of the derived parameters were found to be a strong function of the defining airmass scenarios. The spatial distribution of these scenarios was also determined.

  14. Assessing Seismic Hazards - Algorithms, Maps, and Emergency Scenarios

    NASA Astrophysics Data System (ADS)

    Ferriz, H.

    2007-05-01

    Public officials in charge of building codes, land use planning, and emergency response need sound estimates of seismic hazards. Sources may be well defined (e.g., active faults that have a surface trace) or diffuse (e.g., a subduction zone or a blind-thrust belt), but in both cases one can use a deterministic or worst-case scenario approach. For each scenario, a design earthquake is selected based on historic data or the known length of Holocene ruptures (as determined by geologic mapping). Horizontal ground accelerations (HGAs) can then be estimated at different distances from the earthquake epicenter using published attenuation relations (e.g., Seismological Res. Letters, v. 68, 1997) and estimates of the elastic properties of the substrate materials. No good algorithms are available to take into account reflection of elastic waves across other fault planes (e.g., a common effect in California, where there are many strands of the San Andreas fault), or amplification of waves in water-saturated alluvial and lacustrine basins (e.g., the Mexico City basin), but empirical relations can be developed by correlating historic damage patterns with predicted HGAs. The ultimate result is a map of HGAs. With this map, and with additional data on depth to groundwater and geotechnical properties of local soils, a liquefaction susceptibility map can be prepared, using published algorithms (e.g., J. of Geotech. Geoenv. Eng., v. 127, p. 817-833, 2001; Eng. Geology Practice in N. California, p. 579-594, 2001). Finally, the HGA estimates, digital elevation models, geologic structural data, and geotechnical properties of local geologic units can be used to prepare a slope failure susceptibility map (e.g., Eng. Geology Practice in N. California, p. 77-94, 2001). Seismic hazard maps are used by: (1) Building officials to determine areas of the city where special construction codes have to be implemented, and where existing buildings may need to be retrofitted. (2) Planning officials

  15. Hydrological and water quality impact assessment of a Mediterranean limno-reservoir under climate change and land use management scenarios

    NASA Astrophysics Data System (ADS)

    Molina-Navarro, Eugenio; Trolle, Dennis; Martínez-Pérez, Silvia; Sastre-Merlín, Antonio; Jeppesen, Erik

    2014-02-01

    Water scarcity and water pollution constitute a big challenge for water managers in the Mediterranean region today and will exacerbate in a projected future warmer world, making a holistic approach for water resources management at the catchment scale essential. We expanded the Soil and Water Assessment Tool (SWAT) model developed for a small Mediterranean catchment to quantify the potential effects of various climate and land use change scenarios on catchment hydrology as well as the trophic state of a new kind of waterbody, a limno-reservoir (Pareja Limno-reservoir), created for environmental and recreational purposes. We also checked for the possible synergistic effects of changes in climate and land use on water flow and nutrient exports from the catchment. Simulations showed a noticeable impact of climate change in the river flow regime and consequently the water level of the limno-reservoir, especially during summer, complicating the fulfillment of its purposes. Most of the scenarios also predicted a deterioration of trophic conditions in the limno-reservoir. Fertilization and soil erosion were the main factors affecting nitrate and total phosphorus concentrations. Combined climate and land use change scenarios showed noticeable synergistic effects on nutrients exports, relative to running the scenarios individually. While the impact of fertilization on nitrate export is projected to be reduced with warming in most cases, an additional 13% increase in the total phosphorus export is expected in the worst-case combined scenario compared to the sum of individual scenarios. Our model framework may help water managers to assess and manage how these multiple environmental stressors interact and ultimately affect aquatic ecosystems.

  16. The ShakeOut Earthquake Scenario - A Story That Southern Californians Are Writing

    USGS Publications Warehouse

    Perry, Suzanne; Cox, Dale; Jones, Lucile; Bernknopf, Richard; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne

    2008-01-01

    resulting losses are one realistic outcome, deliberately not a worst-case scenario, rather one worth preparing for and mitigating against. Decades of improving the life-safety requirements in building codes have greatly reduced the risk of death in earthquakes, yet southern California's economic and social systems are still vulnerable to large-scale disruptions. Because of this, the ShakeOut Scenario earthquake would dramatically alter the nature of the southern California community. Fortunately, steps can be taken now that can change that outcome and repay any costs many times over. The ShakeOut Scenario is the first public product of the USGS Multi-Hazards Demonstration Project, created to show how hazards science can increase a community's resiliency to natural disasters through improved planning, mitigation, and response.

  17. Tsunami modeling Scenarios for the Western Black Sea, Shabla seismic area

    NASA Astrophysics Data System (ADS)

    Partheniu, Raluca; Diaconescu, Mihai; Ioane, Dumitru; Ionescu, Constantin; Marmureanu, Alexandru

    2015-04-01

    Although a rare natural phenomenon, tsunami type events in the Black Sea had been generated, past studies showing more than twenty events (Altinok Y., 1999). The western Black Sea could mostly be affected by earthquakes generated in Shabla area, the most known event being generated on 31st of March 1901, when an earthquake with Mw = 7.2 triggered tsunami waves up to 5 m height (Papadopoulos et al., 2011). In order to generate a tsunami in the Black Sea area, earthquakes should mainly follow some conditions: a) to have a magnitude Mw > 6.5; b) to have a focal depth h < 40 km and c) to have an inverse or normal fault focal mechanism. A recent earthquake generated in Shabla area on 05.08.2009, at 07:49 UTC, was taken into consideration for running tsunami scenarios. The following parameters were used as initial conditions: earthquake location (Latitude and Longitude) and one plane solution with preset fault parameters (Strike, Dip, Rake, Width, Length). A set of 18 different tsunami modeling scenarios have been run, varying the Magnitude (Mw = 7, 7.5 and 8) and the Depth (5 km, 10 km and 30 km). The software used for generating the tsunami modeling scenarios is Tsunami Analysis Tool (TAT), developed by Joint Research Centre (JRC) of the European Commission. After analyzing and comparing the generated tsunami modeling scenarios, minimum values of magnitude for tsunami waves generation were evaluated for the Shabla seismic source. For some of the scenarios no tsunami waves were generated. The worst case scenario is for a depth of 5 km, a magnitude Mw = 8, the tsunami waves heights reaching 0.8 m in Kranevo (Bulgaria). The maximum wave heights and some of the affected locations for this scenario show that at Costinesti, Mangalia, Techirghiol cities the waves will reach 0.6 m height and respectively 0.5 m at Constanta city. According to these scenarios, the tsunami generated waves can vary as follows: increasing the depth from 5 to 10 and 30 km will lead to lower heights

  18. High-altitude cerebral oedema mimicking stroke

    PubMed Central

    Yanamandra, Uday; Gupta, Amul; Patyal, Sagarika; Varma, Prem Prakash

    2014-01-01

    High-altitude cerebral oedema (HACO) is the most fatal high-altitude illness seen by rural physicians practising in high-altitude areas. HACO presents clinically with cerebellar ataxia, features of raised intracranial pressure (ICP) and coma. Early identification is important as delay in diagnosis can be fatal. We present two cases of HACO presenting with focal deficits mimicking stroke. The first patient presented with left-sided hemiplegia associated with the rapid deterioration in the sensorium. Neuroimaging revealed features suggestive of vasogenic oedema. The second patient presented with monoplegia of the lower limb. Neuroimaging revealed perfusion deficit in anterior cerebral artery territory. Both patients were managed with dexamethasone and they improved dramatically. Clinical picture and neuroimaging closely resembled acute ischaemic stroke in both cases. Thrombolysis in these patients would have been disastrous. Recent travel to high altitude, young age, absence of atherosclerotic risk factors and features of raised ICP concomitantly directed the diagnosis to HACO. PMID:24671373

  19. Orthokeratinised odontogenic cyst mimicking periapical cyst

    PubMed Central

    Rajalakshmi, R; Sreeja, C; Vijayalakshmi, D; Leelarani, V

    2013-01-01

    Orthokeratinised odontogenic cyst (OOC) denotes the odontogenic cyst that microscopically has an orthokeratinised epithelial lining. OOC is characterised by a less-aggressive behaviour and a low rate of recurrence. This report describes a case of OOC involving posterior part of the mandible that mimicked periapical cyst in a 14-year-old boy. The initial clinical diagnosis was given as periapical cyst based on the clinical and radiographical features. Enucleation of the cyst was performed and the specimen was sent for histopathological examination. A definite diagnosis of OOC was made by histopathological examination of the biopsy specimen. This case emphases on including OOC in the differential diagnosis of radiolucencies occurring in the periapical region of non-vital tooth. PMID:24099763

  20. Orthokeratinised odontogenic cyst mimicking periapical cyst.

    PubMed

    Rajalakshmi, R; Sreeja, C; Vijayalakshmi, D; Leelarani, V

    2013-10-07

    Orthokeratinised odontogenic cyst (OOC) denotes the odontogenic cyst that microscopically has an orthokeratinised epithelial lining. OOC is characterised by a less-aggressive behaviour and a low rate of recurrence. This report describes a case of OOC involving posterior part of the mandible that mimicked periapical cyst in a 14-year-old boy. The initial clinical diagnosis was given as periapical cyst based on the clinical and radiographical features. Enucleation of the cyst was performed and the specimen was sent for histopathological examination. A definite diagnosis of OOC was made by histopathological examination of the biopsy specimen. This case emphases on including OOC in the differential diagnosis of radiolucencies occurring in the periapical region of non-vital tooth.

  1. Mature posterior fossa teratoma mimicking dermoid cyst.

    PubMed

    Bohara, Manoj; Yonezawa, Hajime; Karki, Prasanna; Bakhtiar, Yuriz; Hirano, Hirofumi; Kitazono, Ikumi; Matsuyama, Nozomu; Arita, Kazunori

    2013-10-01

    We describe a very rare case of mature posterior fossa teratoma in an adult who presented with clinico-radiological findings consistent with a dermoid cyst. A computed tomography scan showed a hypodense mass in the cistern magna with calcification and a sinus tract in the occipital bone. Magnetic resonance imaging revealed a hypo- to hyperintense mass without contrast enhancement. The intraoperative picture showed a dermal sinus and a cyst containing lipid, keratin and hair. Histopathological examination showed a tumor with components of all the three germ layers; thereby, a diagnosis of mature teratoma was made. The histopathological differentiation between teratoma and dermoid cyst is very valuable for ruling out the presence of immature/malignant or germinomatous components that would require further adjuvant therapies. Thus, we here present a rare case of posterior fossa teratoma mimicking dermoid cyst and emphasize the importance of histopathological differentiation between these entities.

  2. Infant botulism mimicking an acute abdomen.

    PubMed

    Pisanti, R; Vitiello, R; Formicola, S; Pisanti, A

    2009-12-01

    Botulism is the acute, flaccid paralysis caused by a neurotoxin produced by Clostridium botulinum. In the infant, clinical symptoms are usually unspecific such as poor feeding, weak suck, feeble cry, drooling, followed by a symmetric, descending, flaccid paralysis beginning with the cranial nerve musculature. The initial symptoms of the disease are often similar to several diseases and therefore differential diagnosis is very difficult and rarely suspected by the physician. Since 2004 only 22 cases of infant botulism have been reported in Italy. Since most paediatricians are unfamiliar with the clinical manifestations of infant botulism, the diagnosis can be easily missed. Hence the disease may well be underestimated and underreported. We report a clinical case of botulism presenting initially with abdominal distention, thereby mimicking acute abdomen.

  3. Inherited cardiomyopathies mimicking arrhythmogenic right ventricular cardiomyopathy.

    PubMed

    Roberts, Jason D; Veinot, John P; Rutberg, Julie; Gollob, Michael H

    2010-01-01

    Arrhythmogenic right ventricular cardiomyopathy (ARVC) represents an inherited cardiomyopathy that manifests clinically with malignant ventricular arrhythmias, sudden cardiac death, and less commonly heart failure. The condition is characterized by replacement of the myocardium, primarily of the right ventricle, with fibrofatty tissue. Extensive fibrofatty replacement of the myocardium has been previously thought to be pathognomonic of ARVC; however, this report details two other forms of inherited cardiomyopathy, namely hypertrophic cardiomyopathy (HCM) and the PRKAG2 cardiac syndrome, that were found to have significant fibrofatty myocardial replacement at pathologic examination. This report represents the first documentation of inherited cardiomyopathies mimicking ARVC and highlights the concept that other cardiac conditions can be associated with fibrofatty replacement of the myocardium. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Pulmonary artery sarcoma mimicking pulmonary thromboembolism.

    PubMed

    Celik, Gökhan; Ciledağ, Aydin; Yüksel, Cabir; Yenigün, Bülent Mustafa; Kutlay, Hakan; Yazicıoğlu, Levent; Perçinel, Sibel; Kaya, Akin

    2011-01-01

    A 30 years old male patient was referred to our hospital with a diagnosis of pulmonary thromboembolism due to thorax-computerized tomography (CT) angiography, revealing a thrombus totally occluding left main pulmonary artery. The lesion was evaluated as tumoural mass. Positron emission tomography (PET)-CT revealed pathologic uptake at pulmonary artery mass. Due to localization of tumour, left pneumonectomy was performed. The pathological diagnosis revealed to be pulmonary artery sarcoma. The patient was presented because pulmonary artery sarcomas are very rare tumors and can mimick pulmonary thromboembolism. The true prevalence is underestimated as many pulmonary artery sarcomas are misdiagnosed as pulmonary thromboembolism. PET-CT may help to make a differential diagnosis.

  5. Mimicking semi-convection by convective overshooting

    NASA Astrophysics Data System (ADS)

    Caloi, V.; Mazzitelli, I.

    1990-12-01

    This paper investigates the behavior of so called 'semiconvection' (described by Schwarzschild, 1970; Castellani et al., 1971), of stars burning He in a convective core but exibiting an apparent spontaneous capability to partially mix into the core the matter from outside the formal boundaries of the convective region. A simple numerical algorithm based on a small and ad hoc amount of convective overshooting is presented which, if properly tuned, can mimick the effect of semiconvection in the computation of those stellar evolutionary phases in which a convective helium burning core is present. Using this algorithm, the time-consuming numerical procedures involved in the evaluation of the correct chemical profiles at the boundaries of the formally convective He core can be avoided.

  6. A subtle mimicker in emergency department

    PubMed Central

    Angelis, Maria Vittoria De; Giacomo, Roberta Di; Muzio, Antonio Di; Onofrj, Marco; Bonanni, Laura

    2016-01-01

    Abstract Background: Movement disorder emergencies include any movement disorder which develops over hours to days, in which failure to appropriately diagnose and manage can result in patient morbidity or mortality. Movement disorder emergencies include acute dystonia: sustained or intermittent muscle contractions causing abnormal, often repetitive, movements. Acute dystonia is a serious challenge for emergency room doctors and neurologists, because of the high probability of misdiagnosis, due to the presence of several mimickers including partial seizures, meningitis, localized tetanus, serum electrolyte level abnormalities, strychnine poisoning, angioedema, malingering, catatonia, and conversion. Methods: We describe 2 examples, accompanied by videos, of acute drug-induced oro-mandibular dystonia, both subsequent to occasional haloperidol intake. Results: Management and treatment of this movement disorder are often difficult: neuroleptics withdrawal, treatment with benzodiazepines, and anticholinergics are recommended. Conclusion: Alternative treatment options are also discussed. PMID:27741141

  7. Polypoid uterine lesions mimicking endometrial stromal sarcoma.

    PubMed Central

    McCluggage, W G; Alderdice, J M; Walsh, M Y

    1999-01-01

    Two polypoid submucosal uterine lesions were examined histologically and immunohistochemically with monoclonal antibodies to desmin and alpha smooth muscle actin. One case comprised a leiomyoma and the other a polypoid form of adenomyosis. Both polyps had prolapsed through the external cervical os. The lesions had an ulcerated surface with focal areas of marked increased cellularity and pronounced vascularity throughout, such that they mimicked a low grade endometrial stromal sarcoma infiltrating the myometrium. The cellular areas showed diffuse positivity for desmin and alpha smooth muscle actin, confirming them to be of smooth muscle origin. The changes of marked hypercellularity and pronounced vascularity within polypoid submucosal uterine lesions have not been emphasised in published reports up to now. Pathologists should be aware of these morphological features in order to avoid misdiagnosis of such cases as endometrial stromal sarcomas. The changes described here are likely to be secondary to trauma associated with a polypoid lesion prolapsing through the external cervical os. Images PMID:10605413

  8. Phthriasis Palpebrarum Mimicking Lid Eczema and Blepharitis

    PubMed Central

    Turgut, Burak; Kurt, Julide; Çatak, Onur; Demir, Tamer

    2009-01-01

    Phthiriasis palpebrarum (PP) is a rare eyelid infestation caused by phthirus pubis. We report a case of PP mimicking lid eczema and blepharitis. A 68-year-old woman had moderate itching in both eyes. Her initial diagnosis was considered to be lid eczema or blepharitis because of findings similar to exfoliative lesions and color changes in eyelids and to excretions over eyelashes. Careful observation revealed many lice and translucent nits, protuberances and hyperpigmentary changes, and the buried lice in both eyelids. No hyperemia or secretion was observed on the lids and in the conjunctiva in both eyes. The patient was treated with pilocarpine hydrochloride 4% drops. At the end of the first week, no louse or nit was present. Although it was known that PP is a rare cause of blepharoconjunctivitis, it might observe as an isolated infestation of the eyelids and this condition can easily be misdiagnosed as lid eczema and blepharitis. PMID:20339456

  9. Mimicking Nonequilibrium Steady States with Time-Periodic Driving

    NASA Astrophysics Data System (ADS)

    Raz, O.; Subaşı, Y.; Jarzynski, C.

    2016-04-01

    Under static conditions, a system satisfying detailed balance generically relaxes to an equilibrium state in which there are no currents. To generate persistent currents, either detailed balance must be broken or the system must be driven in a time-dependent manner. A stationary system that violates detailed balance evolves to a nonequilibrium steady state (NESS) characterized by fixed currents. Conversely, a system that satisfies instantaneous detailed balance but is driven by the time-periodic variation of external parameters—also known as a stochastic pump (SP)—reaches a periodic state with nonvanishing currents. In both cases, these currents are maintained at the cost of entropy production. Are these two paradigmatic scenarios effectively equivalent? For discrete-state systems, we establish a mapping between nonequilibrium stationary states and stochastic pumps. Given a NESS characterized by a particular set of stationary probabilities, currents, and entropy production rates, we show how to construct a SP with exactly the same (time-averaged) values. The mapping works in the opposite direction as well. These results establish a proof of principle: They show that stochastic pumps are able to mimic the behavior of nonequilibrium steady states, and vice versa, within the theoretical framework of discrete-state stochastic thermodynamics. Nonequilibrium steady states and stochastic pumps are often used to model, respectively, biomolecular motors driven by chemical reactions and artificial molecular machines steered by the variation of external, macroscopic parameters. Our results loosely suggest that anything a biomolecular machine can do, an artificial molecular machine can do equally well. We illustrate this principle by showing that kinetic proofreading, a NESS mechanism that explains the low error rates in biochemical reactions, can be effectively mimicked by a constrained periodic driving.

  10. Assessments of direct human exposure: the approach of EU risk assessments compared to scenario-based risk assessment.

    PubMed

    Wormuth, Matthias; Demou, Evangelia; Scheringer, Martin; Hungerbühler, Konrad

    2007-08-01

    The awareness of potential risks emerging from the use of chemicals in all parts of daily life has increased the need for risk assessments that are able to cover a high number of exposure situations and thereby ensure the safety of workers and consumers. In the European Union (EU), the practice of risk assessments for chemicals is laid down in a Technical Guidance Document; it is designed to consider environmental and human occupational and residential exposure. Almost 70 EU risk assessment reports (RARs) have been finalized for high-production-volume chemicals during the last decade. In the present study, we analyze the assessment of occupational and consumer exposure to trichloroethylene and phthalates presented in six EU RARs. Exposure scenarios in these six RARs were compared to scenarios used in applications of the scenario-based risk assessment approach to the same set of chemicals. We find that scenarios used in the selected EU RARs to represent typical exposure situations in occupational or private use of chemicals and products do not necessarily represent worst-case conditions. This can be due to the use of outdated information on technical equipment and conditions in workplaces or omission of pathways that can cause consumer exposure. Considering the need for exposure and risk assessments under the new chemicals legislation of the EU, we suggest that a transparent process of collecting data on exposure situations and of generating representative exposure scenarios is implemented to improve the accuracy of risk assessments. Also, the data sets used to assess human exposure should be harmonized, summarized in a transparent fashion, and made accessible for all risk assessors and the public.

  11. Experimental Evaluation of PV Inverter Anti-Islanding with Grid Support Functions in Multi-Inverter Island Scenarios

    SciTech Connect

    Hoke, Anderson; Nelson, Austin; Miller, Brian; Chakraborty, Sudipta; Bell, Frances; McCarty, Michael

    2016-07-01

    based anti-islanding tests to determine the worst-case configuration of grid support functions for each inverter. A grid support function is a function an inverter performs to help stabilize the grid or drive the grid back towards its nominal operating point. The four grid support functions examined here were voltage ride-through, frequency ride-through, Volt-VAr control, and frequency-Watt control. The worst-case grid support configuration was defined as the configuration that led to the maximum island duration (or run-on time, ROT) out of 50 tests of each inverter. For each of the three inverters, it was observed that maximum ROT increased when voltage and frequency ride-through were activated. No conclusive evidence was found that Volt-VAr control or frequency-Watt control increased maximum ROT. Over all single-inverter test cases, the maximum ROT was 711 ms, well below the two-second limit currently imposed by IEEE Standard 1547-2003. A subsequent series of 244 experiments tested all three inverters simultaneously in the same island. These tests again used a procedure based on the IEEE 1547.1 unintentional islanding test to create a difficult-to-detect island condition. For these tests, which used the two worst-case grid support function configurations from the single-inverter tests, the inverters were connected to a variety of island circuit topologies designed to represent the variety of multiple-inverter islands that may occur on real distribution circuits. The interconnecting circuits and the resonant island load itself were represented in the real-time PHIL model. PHIL techniques similar to those employed here have been previously used and validated for anti-islanding tests, and the PHIL resonant load model used in this test was successfully validated by comparing single-inverter PHIL tests to conventional tests using an RLC load bank.

  12. Evolving practices in environmental scenarios: a new scenario typology

    NASA Astrophysics Data System (ADS)

    Wilkinson, Angela; Eidinow, Esther

    2008-10-01

    A new approach to scenarios focused on environmental concerns, changes and challenges, i.e. so-called 'environmental scenarios', is necessary if global environmental changes are to be more effectively appreciated and addressed through sustained and collaborative action. On the basis of a comparison of previous approaches to global environmental scenarios and a review of existing scenario typologies, we propose a new scenario typology to help guide scenario-based interventions. This typology makes explicit the types of and/or the approaches to knowledge ('the epistemologies') which underpin a scenario approach. Drawing on previous environmental scenario projects, we distinguish and describe two main types in this new typology: 'problem-focused' and 'actor-centric'. This leads in turn to our suggestion for a third type, which we call 'RIMA'—'reflexive interventionist or multi-agent based'. This approach to scenarios emphasizes the importance of the involvement of different epistemologies in a scenario-based process of action learning in the public interest. We suggest that, by combining the epistemologies apparent in the previous two types, this approach can create a more effective bridge between longer-term thinking and more immediate actions. Our description is aimed at scenario practitioners in general, as well as those who work with (environmental) scenarios that address global challenges.

  13. Uncertainty in local and regional tsunami earthquake source parameters: Implications for scenario based hazard assessment and forecasting

    NASA Astrophysics Data System (ADS)

    Müller, Christof; Power, William; Burbidge, David; Wang, Xiaoming

    2016-04-01

    Over the last decade tsunami propagation models have been used extensively for both tsunami forecasting, hazard and risk assessment. However, the effect of uncertainty in the earthquake source parameters, such as location and distribution of slip in the earthquake source on the results of the tsunami model has not always been examined in great detail. We have developed a preliminary combined and continuous Hikurangi-Kermadec subduction zone interface model. The model is defined by a spline surface and is based on a previously published spline model for Hikurangi interface and a more traditional unit source model for the Kermadec interface. The model allows to freely position and vary the earthquake epicenter and to consider non-uniform slip. Using this model we have investigated the effects of variability in non-uniform slip and epicenter location on the distribution of offshore maximum wave heights for local New Zealand targets. Which scenario out of an ensemble is responsible for the maximum wave height locally is a spatially highly variable function of earthquake location and/or the distribution of slip. We use the Coefficient of Variation (CoV) to quantify the variability of offshore wave heights as a function of source location and distribution of slip. CoV increases significantly with closer proximity to the shore, in bays and in shallow water. The study has implication for tsunami hazard assessment and forecasting. As an example, our results challenge the concept of hazard assessment using a single worst case scenario in particular for local tsunami.

  14. Hydroxychloroquine-associated hyperpigmentation mimicking elder abuse.

    PubMed

    Cohen, Philip R

    2013-12-01

    Hydroxychloroquine may result in cutaneous dyschromia. Older individuals who are the victims of elder abuse can present with bruising and resolving ecchymoses. The features of hydroxychloroquine-associated hyperpigmentation are described, the mucosal and skin manifestations of elder abuse are reviewed, and the mucocutaneous mimickers of elder abuse are summarized. An elderly woman being treated with hydroxychloroquine for systemic lupus erythematosus developed drug-associated black and blue pigmentation of her skin. The dyschromia was misinterpreted by her clinician as elder abuse and Adult Protective Services was notified. The family was eventually cleared of suspected elder abuse. A skin biopsy of the patient's dyschromia confirmed the diagnosis of hydroxychloroquine-associated hyperpigmentation. Hyperpigmentation of skin, mucosa, and nails can be observed in patients treated with antimalarials, including hydroxychloroquine. Elder abuse is a significant and underreported problem in seniors. Cutaneous findings can aid in the discovery of physical abuse, sexual abuse, and self-neglect in elderly individuals. However, medication-associated effects, systemic conditions, and accidental external injuries can mimic elder abuse. Therefore, a complete medical history and appropriate laboratory evaluation, including skin biopsy, should be conducted when the diagnosis of elder abuse is suspected.

  15. Cervical spinal meningioma mimicking intramedullary spinal tumor.

    PubMed

    Senturk, Senem; Guzel, Aslan; Guzel, Ebru; Bayrak, Aylin Hasanefendioğlu; Sav, Aydin

    2009-01-01

    Case report. To report a very unusual spinal meningioma, mimicking an intramedullary spinal tumor. Spinal meningiomas, usually associated with signs and symptoms of cord or nerve root compression, are generally encountered in women aged over 40. Radiologic diagnosis is often established by their intradural extramedullary location on magnetic resonance images. A 60-year-old woman had a 6-month history of progressive weakness in her upper extremities, difficulty in walking, and cervical pain radiating through both arms. Neurologic examination revealed motor strength deficiency in all her extremities, with extensor reflexes, clonus, and bilateral hyper-reflexiveness. A sensory deficit was present all over her body. Magnetic resonance images revealed that the spinal cord appeared expanded with an ill-defined, homogeneously contrast-enhanced, lobulated, eccentric mass at the C1-C3 level. The patient was operated with a preliminary diagnosis of an intramedullary tumor. At surgery, the mass was found to be extramedullary, and gross total resection was performed. Histopathological examination revealed a meningioma characterized by the presence of fibrous and meningothelial components. The patient was able to ambulate with a cane, and extremity strength and sensation improved 2 months after surgery. Spinal meningiomas can mimic intramedullary tumors, and should be considered in differential diagnosis of intradural tumors with atypical appearance.

  16. Mammary analogue secretory carcinoma mimicking salivary adenoma.

    PubMed

    Williams, Lindsay; Chiosea, Simion I

    2013-12-01

    Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumor characterized by ETV6 translocation. It appears that prior studies have identified MASC by reviewing salivary gland carcinomas, such as acinic cell carcinoma and adenocarcinoma, not otherwise specified. To address the possibility of MASC mimicking benign salivary neoplasms we reviewed 12 salivary gland (cyst)adenomas diagnosed prior to the discovery of MASC. One encapsulated (cyst)adenoma of the parotid gland demonstrated features of MASC. The diagnosis was confirmed by fluorescence in situ hybridization with an ETV6 break-apart probe. An unusual complex pattern of ETV6 rearrangement with duplication of the telomeric/distal ETV6 probe was identified. This case illustrates that MASC may mimic salivary (cyst)adenomas. To more accurately assess true clinical and morphologic spectrum of MASC, future studies may have to include review of salivary (cyst)adenomas. The differential diagnosis of MASC may have to be expanded to include cases resembling salivary (cyst)adenomas.

  17. Mimicking Melanosomes: Polydopamine Nanoparticles as Artificial Microparasols

    PubMed Central

    2017-01-01

    A primary role of melanin in skin is the prevention of UV-induced nuclear DNA damage to human skin cells, where it serves to screen out harmful UV radiation. Melanin is delivered to keratinocytes in the skin after being excreted as melanosomes from melanocytes. Defects in melanin production in humans can cause diseases, many of which currently lack effective treatments due to their genetic origins (e.g., skin cancer, vitiligo, and albinism). The widespread prevalence of melanin-related diseases and an increasing interest in the performance of various polymeric materials related to melanin necessitates novel synthetic routes for preparing melanin-like materials. In this work, we prepared melanin-like nanoparticles (MelNPs) via spontaneous oxidation of dopamine, as biocompatible, synthetic analogues of naturally occurring melanosomes, and investigated their uptake, transport, distribution, and UV-protective capabilities in human keratinocytes. Critically, we demonstrate that MelNPs are endocytosed, undergo perinuclear aggregation, and form a supranuclear cap, or so-called microparasol in human epidermal keratinocytes (HEKa), mimicking the behavior of natural melananosomes in terms of cellular distribution and the fact that they serve to protect the cells from UV damage. PMID:28691067

  18. [Infestation with Enterobius vermicularis mimicking appendicitis].

    PubMed

    Levens, Afra M A; Schurink, Maarten; Koetse, Harma A; van Baren, Robertine

    2014-01-01

    Gastrointestinal infestation with the parasite Enterobius vermicularis is common in humans and is usually harmless. Anal pruritus is the most characteristic symptom, but the parasites can cause severe abdominal pain mimicking appendicitis. Early recognition can prevent an unnecessary appendectomy. A six-year-old girl reported to the accident and emergency department with pain in the lower right abdominal region. She was admitted and treated for suspected perforated appendix, following physical examination supplemented with an abdominal CT scan. After antibiotic treatment the symptoms disappeared as did the abscess, apart from a minor amount of residual infiltrate. She was then readmitted twice with recurrent abdominal pain without radiological evidence of an abdominal focus. We decided to conduct a diagnostic laparoscopy and an elective appendectomy à froid. During this procedure living worms were found in the appendix. Treatment with the anthelminthicum mebendazol was effective. Gastro-intestinal infestation with E. vermicularis is very common, especially in young children. This infestation is usually harmless, but can mimic appendicitis. This infestation is easily treatable with mebendazol.

  19. Microfabricated adhesive mimicking gecko foot-hair

    NASA Astrophysics Data System (ADS)

    Geim, A. K.; Dubonos, S. V.; Grigorieva, I. V.; Novoselov, K. S.; Zhukov, A. A.; Shapoval, S. Yu.

    2003-07-01

    The amazing climbing ability of geckos has attracted the interest of philosophers and scientists alike for centuries. However, only in the past few years has progress been made in understanding the mechanism behind this ability, which relies on submicrometre keratin hairs covering the soles of geckos. Each hair produces a miniscule force ~10-7 N (due to van der Waals and/or capillary interactions) but millions of hairs acting together create a formidable adhesion of ~10 N cm-2: sufficient to keep geckos firmly on their feet, even when upside down on a glass ceiling. It is very tempting to create a new type of adhesive by mimicking the gecko mechanism. Here we report on a prototype of such 'gecko tape' made by microfabrication of dense arrays of flexible plastic pillars, the geometry of which is optimized to ensure their collective adhesion. Our approach shows a way to manufacture self-cleaning, re-attachable dry adhesives, although problems related to their durability and mass production are yet to be resolved.

  20. Pontine lesions mimicking acute peripheral vestibulopathy

    PubMed Central

    Thomke, F.; Hopf, H. C.

    1999-01-01

    OBJECTIVES—Clinical signs of acute peripheral vestibulopathy (APV) were repeatedly reported with pontine lesions. The clinical relevance of such a mechanism is not known, as most studies were biased by patients with additional clinical signs of brainstem dysfunction.
METHODS—Masseter reflex (MassR), blink reflex (BlinkR), brainstem auditory evoked potentials (BAEPs), and DC electro-oculography (EOG) were tested in 232 consecutive patients with clinical signs of unilateral APV.
RESULTS—Forty five of the 232 patients (19.4%) had at least one electrophysiological abnormality suggesting pontine dysfunction mainly due to possible vertebrobasilar ischaemia (22 patients) and multiple sclerosis (eight patients). MassR abnormalities were seen in 24patients, and EOG abnormalities of saccades and following eye movements occurred in 22 patients. Three patients had BlinkR-R1 abnormalities, and one had delayed BAEP waves IV and V. Clinical improvement was almost always (32 of 34 re-examined patients) associated with improvement or normalisation of at least one electrophysiological abnormality. Brain MRI was done in 25 of the 44 patients and confirmed pontine lesions in six (two infarcts, three inflammations, one tumour).
CONCLUSIONS—Pontine dysfunction was suggested in 45 of 232 consecutive patients with clinical signs of APV on the basis of abnormal electrophysiological findings, and was mainly attributed to brainstem ischaemia and multiple sclerosis. The frequency of pontine lesions mimicking APV is underestimated if based on MRI established lesions only.

 PMID:10084533

  1. Vitamin D Deficiency Rickets Mimicking Pseudohypoparathyroidism

    PubMed Central

    Kurtoğlu, Selim; Yıldız, Aysel; Akın, Mustafa Ali; Kendirici, Mustafa

    2010-01-01

    Vitamin D deficiency rickets (VDDR) is a disorder biochemically characterized by elevated serum alkaline phosphatase (ALP) activity, normal or decreased serum calcium (Ca) and inorganic phosphate concentrations, secondary hyperparathyroidism and decreased serum 25−hydroxyvitamin D (25(OH)D) levels. In stage 1 VDDR, urinary amino acid and phosphate excretion are normal with minimal or no findings of rickets on radiographs. Pseudohypoparathyroidism (PHP) is an inherited disorder characterized by end−organ resistance to parathormone (PTH). VDDR occasionally resembles PHP type 2 in clinical presentation and biochemical features, creating difficulties in the differential diagnosis of these two entities. Here we report an infant diagnosed with VDDR. In addition to inadequate vitamin D intake, usage of antiepileptic drugs (AED) may have led to the worsening of the vitamin D deficiency. The patient presented with a history of febrile convulsions, for which he received phenobarbital treatment. The initial findings of hypocalcemia, hyperphosphatemia and normal tubular reabsorption of phosphate, mimicking PHP 2, responded well to vitamin D and oral Ca treatment with normalization of serum Ca, phosphorus (P), ALP and PTH levels Conflict of interest:None declared. PMID:21274319

  2. Ruptured hepatic abscess mimicking perforated viscus.

    PubMed

    Lai, Yen-Chun; Su, Yu-Jang; Chang, Wen-Han

    2008-11-01

    In the majority of pneumoperitoneum cases we diagnose perforated viscus. We present herein a case of ruptured hepatic abscess mimicking perforated viscus. A 40-year-old man presented to the emergency room with fever and right upper quadrant abdominal pain. The fever had been on/off for a period of 1 month. On physical examination, diffuse abdominal pain with rebounding tenderness was noted. Blood tests showed leukocytosis with left shift, hyperglycemia, and elevated liver function tests. A chest X-ray showed a subdiaphragmatic region air-fluid level, indicating a hepatic abscess. Pneumoperitoneum was also seen. Owing to the status of peritonitis, computed tomography (CT) of the abdomen was performed and revealed an air-containing liver abscess in the right lobe of the liver. Perforation of a hollow organ was also suspected because of the pneumoperitoneum. An emergent laparotomy was immediately performed for the suspicion of a hollow organ perforation. No perforation of the hollow viscus was found. The ruptured hepatic abscess was attributed to the pneumoperitoneum. A blood culture grew Klebsiella pneumoniae four days later, and the same organism was also found in a surgical specimen culture of the abscess. For a ruptured hepatic abscess, surgical intervention with draining of the abscess and cleaning of the abdominal cavity are essential to save patient lives.

  3. Egg white ovalbumin digestion mimicking physiological conditions.

    PubMed

    Martos, Gustavo; Contreras, Patricia; Molina, Elena; López-Fandiño, Rosina

    2010-05-12

    Gastrointestinal digestion of ovalbumin (OVA) was simulated using an in vitro system in two steps, which mimicked digestion in the stomach and duodenum, to assess the effect of different gastric pHs, different concentrations of proteases, and the presence of surfactants, such as phosphatidylcholine (PC) and bile salts (BS). OVA was very resistant to pepsin action at an enzyme/substrate ratio that would resemble a physiological situation (1:20 w/w, 172 units/mg) at pH values equal or above 2. The presence of PC did not change the susceptibility of OVA to proteolysis with pepsin. Fluorescence experiments showed that OVA interacted with PC vesicles, particularly at acidic pH, but it is likely that the protein maintained a high degree of conformational stability, resisting pepsin action. The presence of BS at physiological concentrations considerably increased the proteolysis of OVA by a mixture of pancreatic enzymes. The addition of PC made OVA even more sensitive to proteolytic degradation, suggesting that OVA could associate with the surfactants under duodenal conditions, increasing its exposure to pancreatic proteinases. Immunoreactivity against IgE from sera of allergic patients was retained after in vitro gastric digestion, depending on the reactivity of the sera, but it decreased considerably after in vitro duodenal digestion.

  4. Scenario Planning in Higher Education.

    ERIC Educational Resources Information Center

    Rieley, James B.

    1997-01-01

    Proposes scenario planning in preparing for the future of higher education. Delineates a methodology for effective scenario planning: identifying potential future scenarios; examining social, economic, political, environmental, and technological influences; exploring mental models while looking through systems maps, and developing potential…

  5. Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

    SciTech Connect

    Inman, D.; Vimmerstedt, L.; Bush, B.; Peterson, S.

    2014-04-01

    Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

  6. Non-harmful insertion of data mimicking computer network attacks

    DOEpatents

    Neil, Joshua Charles; Kent, Alexander; Hash, Jr, Curtis Lee

    2016-06-21

    Non-harmful data mimicking computer network attacks may be inserted in a computer network. Anomalous real network connections may be generated between a plurality of computing systems in the network. Data mimicking an attack may also be generated. The generated data may be transmitted between the plurality of computing systems using the real network connections and measured to determine whether an attack is detected.

  7. Repository preclosure accident scenarios

    SciTech Connect

    Yook, H.R.; Arbital, J.G.; Keeton, J.M.; Mosier, J.E.; Weaver, B.S.

    1984-09-01

    Waste-handling operations at a spent-fuel repository were investigated to identify operational accidents that could occur. The facility was subdivided, through systems engineering procedures, into individual operations that involve the waste and one specific component of the waste package, in one specific area of the handling facility. From this subdivision approximately 600 potential accidents involving waste package components were identified and then discussed. Supporting descriptive data included for each accident scenario are distance of drop, speed of collision, weight of package component, and weight of equipment involved. The energy of impact associated with each potential accident is calculated to provide a basis for comparison of the relative severities of all the accidents. The results and conclusions suggest approaches to accident consequence mitigation through waste package and facility design. 35 figures, 9 tables.

  8. Noncavernous arteriovenous shunts mimicking carotid cavernous fistulae

    PubMed Central

    Kobkitsuksakul, Chai; Jiarakongmun, Pakorn; Chanthanaphak, Ekachat; Singhara Na Ayudya, Sirintara (Pongpech)

    2016-01-01

    PURPOSE The classic symptoms and signs of carotid cavernous sinus fistula or cavernous sinus dural arteriovenous fistula (AVF) consist of eye redness, exophthalmos, and gaze abnormality. The angiography findings typically consist of arteriovenous shunt at cavernous sinus with ophthalmic venous drainage with or without cortical venous reflux. In rare circumstances, the shunts are localized outside the cavernous sinus, but mimic symptoms and radiography of the cavernous shunt. We would like to present the other locations of the arteriovenous shunt, which mimic the clinical presentation of carotid cavernous fistulae, and analyze venous drainages. METHODS We retrospectively examined the records of 350 patients who were given provisional diagnoses of carotid cavernous sinus fistulae or cavernous sinus dural AVF in the division of Interventional Neuroradiology, Ramathibodi Hospital, Bangkok between 2008 and 2014. Any patient with cavernous arteriovenous shunt was excluded. RESULTS Of those 350 patients, 10 patients (2.85%) were identified as having noncavernous sinus AVF. The angiographic diagnoses consisted of three anterior condylar (hypoglossal) dural AVF, two traumatic middle meningeal AVF, one lesser sphenoid wing dural AVF, one vertebro-vertebral fistula (VVF), one intraorbital AVF, one direct dural artery to cortical vein dural AVF, and one transverse-sigmoid dural AVF. Six cases (60%) were found to have venous efferent obstruction. CONCLUSION Arteriovenous shunts mimicking the cavernous AVF are rare, with a prevalence of only 2.85% in this series. The clinical presentation mainly depends on venous outflow. The venous outlet of the arteriovenous shunts is influenced by venous afferent-efferent patterns according to the venous anatomy of the central nervous system and the skull base, as well as by architectural disturbance, specifically, obstruction of the venous outflow. PMID:27767958

  9. Scenario-based assessment of buildings damage and population exposure due to tsunamis for the town of Alexandria, Egypt

    NASA Astrophysics Data System (ADS)

    Pagnoni, G.; Armigliato, A.; Tinti, S.

    2015-08-01

    Alexandria is the second biggest city in Egypt as regards population, is a key economic area in northern Africa and has a very important tourist activity. Historical catalogues indicate that it was severely affected by a number of tsunami events. In this work we assess the tsunami hazard by running numerical simulations of tsunami impact in Alexandria through the Worst-case Credible Tsunami Scenario Analysis (WCTSA). We identify three main seismic sources: the Western Hellenic Arc (WHA - reference event AD 365, Mw = 8.5), the Eastern Hellenic Arc (EHA - reference event 1303, Mw = 8.0) and the Cyprus Arc (CA - hypothetical scenario earthquake with Mw = 8.0), inferred from the tectonic setting and from historical tsunami catalogues. All numerical simulations are carried out by means of the code UBO-TSUFD, developed and maintained by the Tsunami Research Team of the University of Bologna. Relevant tsunami metrics are computed for each scenario and then used to build aggregated fields such as the maximum flood depth and the maximum inundation area. We find that the case that produces the most relevant flooding in Alexandria is the EHA scenario, with wave heights up to 4 m. The aggregate fields are used for a building vulnerability assessment according to a methodology developed in the frame of the EU-FP6 project SCHEMA and further refined in this study, based on the adoption of a suitable building damage matrix and on water inundation depth. It is found that in the districts of El Dekhila and Al Amriyah, to the south-west of the port of Dekhila over 12 000 buildings could be affected and hundreds of them could incur in consequences ranging from important damage to total collapse. It is also found that in the same districts tsunami inundation covers an area of about 15 km2 resulting in more than 150 000 residents being exposed.

  10. Modelling future fire probability in the Brazilian Amazon under different land-use and climate change scenarios

    NASA Astrophysics Data System (ADS)

    Fonseca, Marisa; Alves, Lincoln; Aguiar, Ana Paula; Anderson, Liana; Aragão, Luiz

    2017-04-01

    Climate and land-use change are expected to amplify fire incidence in the Amazon. Modelling the influence of land-use and climate change scenarios on fire occurrence is therefore important to better understand their impacts on the carbon emissions and ecosystems' degradation in the region. Here we use the Maximum Entropy method (MaxEnt) to estimate the impact of different climate and land-use change scenarios on the relative fire probability (RFP) during the 2071-2099 period in the Brazilian Amazon with a 0.25° spatial resolution. The model was calibrated using satellite-based fire detections during the 2006-2015 period (hereafter "baseline"). The land-use change variables were obtained considering alternative pathways of clear-cut deforestation, secondary vegetation and old growth forest degradation resulting from major socioeconomic, institutional and environmental dynamics in the region. The climatic variables were generated using a regional model (ETA) nested in an earth system global model (HadGEM2-ES). A land-use "sustainability" scenario considering that institutional and political conditions would favour the increase in forest regeneration and decrease of the old growth forest degradation and clear-cut deforestation rates was combined with the representative concentration pathway (RCP) 4.5 climatic scenario (hereafter SUST-4.5). To access the worst-case scenario of fire incidence, a "fragmentation" land-use scenario, representing the opposite tendency of the "sustainability" conditions, was combined with the climatic variables resulting from the RCP 8.5 (FRAG-8.5). The test AUC (area under de curve) metric (0.768 ± 0.018) indicated satisfactory model performance. In the FRAG-8.5 scenario 63% ( 2.900.000 km2) of the study region shows from 0.35 to 0.55 of RFP, while in the baseline and under the SUST-4.5 scenario, 30% and 40% of the region is within this range of RFP, respectively. Conversely, in the baseline 29% of the area shows up to 0.1 RFP, but this

  11. Diagnosis and perioperative management of ruptured AAA mimicking symptomatic groin hernia

    PubMed Central

    Klein, Holger Jan; Becker, Daniel; Rancic, Zoran

    2015-01-01

    Introduction Ruptured abdominal aortic aneurysm (RAAA) can infrequently present as symptomatic groin hernia. This misleading form of presentation often leads to erroneous preoperative management resulting in poor survival. Case presentation Two patients with RAAA mimicking symptomatic groin hernia underwent different preoperative managements pointing out the importance of the principles of hypotensive haemostasis in the scope of this emergency scenario. Conclusion Computed Tomography Angiography (CTA) remains the recommended diagnostic tool—for both safe diagnosis of the ruptured aneurysm and precise preoperative planning. Endovascular aortic repair of the RAAA—if feasible—is the treatment of choice. This rare form of RAAA manifestation should call physicians attention—especially in patients with known abdominal aortic aneurysms in their preceding medical history. PMID:26656148

  12. Natural Disaster Scenarios in the Food Security Early Warning Contingency Planning Process: The Role of Remotely Sensed Vegetation and Rainfall Data

    NASA Astrophysics Data System (ADS)

    Brown, M. E.; Funk, C. C.; Choularton, R.

    2006-12-01

    In this talk, we will explore how scenarios are used in early warning systems in Africa as they respond to the food security consequences of droughts and floods, and determine ways EWS could use remote sensing products more effectively. Early warning of an incipient agricultural drought triggers the contingency planning process at the national governmental level, supported by international organizations such as USAID's Famine Early Warning Network or FEWS NET. Contingency planning focuses on updating relevant national contingency plans. These scenarios are usually described as `Worst Case', `Mid-Case', and `Best Case', and focus on providing guidance for humanitarian organizations' assistance planning process. There is an increasingly apparent need to provide appropriate, nuanced, and constructive assistance. Remote sensing can support this objective by providing earlier early warning, giving aid organizations the time necessary to coordinate effective aid packages and policies. In this talk we will explore how recently developed projections of vegetation data one to four months into the future could be used to guide the scenarios both spatially and temporally, and provide probabilities for which case is most likely to occur. A case study of Ethiopia and its contingency planning process for the past few years will be presented.

  13. Restless legs syndrome mimicking S1 radiculopathy.

    PubMed

    Zambelis, Th; Wolgamuth, B R; Papoutsi, S N; Economou, N T

    2016-01-01

    mimicking several pathological conditions, Restless Legs Syndrome prevalence on general population according to various large epidemiological studies and pathogenic hypotheses on the issue of Restless Legs Syndrome are discussed. Finally, by presenting another possible "RLS-mimic" our aim is to highlight the common misdiagnosis of Restless Legs Syndrome, which can mimic a variety of disorders, some of which are very common, such as an S1 radiculopathy, thus raising concern among doctors of various specialties addressed to by Restless Legs Syndrome sufferers, on the importance of proper diagnosis of the syndrome.

  14. Learning from global emissions scenarios

    NASA Astrophysics Data System (ADS)

    O'Neill, Brian C.; Nakicenovic, Nebojsa

    2008-10-01

    Scenarios of global greenhouse gas emissions have played a key role in climate change analysis for over twenty years. Currently, several research communities are organizing to undertake a new round of scenario development in the lead-up to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). To help inform this process, we assess a number of past efforts to develop and learn from sets of global greenhouse gas emissions scenarios. We conclude that while emissions scenario exercises have likely had substantial benefits for participating modeling teams and produced insights from individual models, learning from the exercises taken as a whole has been more limited. Model comparison exercises have typically focused on the production of large numbers of scenarios while investing little in assessing the results or the production process, perhaps on the assumption that later assessment efforts could play this role. However, much of this assessment potential remains untapped. Efforts such as scenario-related chapters of IPCC reports have been most informative when they have gone to extra lengths to carry out more specific comparison exercises, but in general these assessments do not have the remit or resources to carry out the kind of detailed analysis of scenario results necessary for drawing the most useful conclusions. We recommend that scenario comparison exercises build-in time and resources for assessing scenario results in more detail at the time when they are produced, that these exercises focus on more specific questions to improve the prospects for learning, and that additional scenario assessments are carried out separately from production exercises. We also discuss the obstacles to better assessment that might exist, and how they might be overcome. Finally, we recommend that future work include much greater emphasis on understanding how scenarios are actually used, as a guide to improving scenario production.

  15. Scenario Planning and Collection Development.

    ERIC Educational Resources Information Center

    Giesecke, Joan

    1999-01-01

    Discussion of the future of library collection development and the need for planning focuses on the technique of scenario planning and discusses the results of scenario planning at the University of NebraskaLincoln that examined collection development and digital information. (LRW)

  16. Scenario Planning in Higher Education.

    ERIC Educational Resources Information Center

    Rieley, James

    Scenario planning can help institutions change the mental models used in planning to achieve a focus on the long-term future, rather than on the immediate future. While institutional survival depends upon the ability to detect and adapt to critical changes in the environment, all institutions face a wide range of potential future scenarios. By…

  17. Student Rights and Responsibilities Scenarios.

    ERIC Educational Resources Information Center

    Peterson, Ludwig A.; And Others

    To stimulate interest in student's rights and responsibilities, this resource contains incomplete scenarios dealing with the consequences of knowing and not knowing the law, as it is applied to modern practical situations. The scenarios can be used in high school courses such as government, social problems, history, psychology, and business law.…

  18. Student Rights and Responsibilities Scenarios.

    ERIC Educational Resources Information Center

    Peterson, Ludwig A.; And Others

    To stimulate interest in student's rights and responsibilities, this resource contains incomplete scenarios dealing with the consequences of knowing and not knowing the law, as it is applied to modern practical situations. The scenarios can be used in high school courses such as government, social problems, history, psychology, and business law.…

  19. Futures Scenario in Science Learning

    ERIC Educational Resources Information Center

    Lloyd, David; Vanderhout, Annastasia; Lloyd, Lisa; Atkins, David

    2010-01-01

    In this article we describe our experiences in developing futures scenarios in two science contexts, space science and atmospheric science/climate change. Futures scenario writing can develop scientific literacy by connecting science learning to students' lifeworlds--past, present and future. They also provide a synthesising mechanism for…

  20. Munchausen syndrome mimicking psychiatric disease with concomitant genuine physical illness

    PubMed Central

    Almeida, Jaime; da Silva, Joaquim Alves; Xavier, Miguel; Gusmão, Ricardo

    2010-01-01

    Munchausen syndrome is a disorder in which patients intentionally produce symptoms mimicking physical or psychiatric illnesses with the aim to assume the sick role and to gain medical attention. Once a patient receives a Munchausen syndrome diagnosis every complaint made thence tends to be regarded with scepticism by clinical staff. However, it is possible that a bona fide illness, which might be disregarded, may coexist in these patients. We report a case of MS mimicking psychiatric disease with concomitant genuine acute physical illness. Despite the initial doubts about the veracity of the latter, due to its prompt recognition, treatment was successful. PMID:22798096

  1. Tsunami inundation scenarios and tsunami vulnerability assessment for the town of Alexandria, Egypt

    NASA Astrophysics Data System (ADS)

    Tinti, S.; Pagnoni, G.; Armigliato, A.; Tonini, R.

    2012-04-01

    Historical catalogues indicate that Alexandria was severely affected in the past by several tsunami events. The tsunami hazard in that area is mainly due to far-field tectonic sources. The two most famous earthquakes that generated tsunamis whose impact was experienced also by Alexandria and the surrounding area are the 365 AD and the 1303 earthquakes, whose sources are still a matter of debate but are frequently located in correspondence with the western and eastern sectors of the Hellenic Arc. Nowadays, Alexandria is the second biggest city in Egypt as regards population (3.9 million), it is a key economic area in northern Africa and it has a very important tourist activity. Hence the proper assessment of tsunami hazard-to-risk must be regarded as an important task, which was partially undertaken in the very recent past by projects such as TRANSFER (EU-FP6). It is also worth mentioning that the overall eastern Mediterranean is one of the areas chosen by the EU-FP7 Project TRIDEC to test a new generation Tsunami Early Warning Decision Support System. We assess the hazard by performing numerical simulations of tsunami impact in Alexandria through the worst-case scenario technique. We identify three main seismic sources: the western Hellenic Arc (reference event 365 AD, magnitude 8.3), the eastern Hellenic Arc (reference event 1303, magnitude 8.0) and the Cyprus arc (hypothetical scenario with magnitude 8.0, inferred from the tectonic setting and the historical seismic catalogues). All the simulations and the inundation maps are computed by means of the UBO-TSUFD code, developed and maintained by the Tsunami Research team of the University of Bologna, which solves the non-linear shallow-water equations allowing for the computation of run-up and inundation on nested grids. For each of the considered scenarios we compute all the relevant tsunami metrics, i.e. water elevation, current speed, flow depth and momentum flux. We find that the case that produces the most

  2. Assessment of the water supply:demand ratios in a Mediterranean basin under different global change scenarios and mitigation alternatives.

    PubMed

    Boithias, Laurie; Acuña, Vicenç; Vergoñós, Laura; Ziv, Guy; Marcé, Rafael; Sabater, Sergi

    2014-02-01

    Spatial differences in the supply and demand of ecosystem services such as water provisioning often imply that the demand for ecosystem services cannot be fulfilled at the local scale, but it can be fulfilled at larger scales (regional, continental). Differences in the supply:demand (S:D) ratio for a given service result in different values, and these differences might be assessed with monetary or non-monetary metrics. Water scarcity occurs where and when water resources are not enough to meet all the demands, and this affects equally the service of water provisioning and the ecosystem needs. In this study we assess the value of water in a Mediterranean basin under different global change (i.e. both climate and anthropogenic changes) and mitigation scenarios, with a non-monetary metric: the S:D ratio. We computed water balances across the Ebro basin (North-East Spain) with the spatially explicit InVEST model. We highlight the spatial and temporal mismatches existing across a single hydrological basin regarding water provisioning and its consumption, considering or not, the environmental demand (environmental flow). The study shows that water scarcity is commonly a local issue (sub-basin to region), but that all demands are met at the largest considered spatial scale (basin). This was not the case in the worst-case scenario (increasing demands and decreasing supply), as the S:D ratio at the basin scale was near 1, indicating that serious problems of water scarcity might occur in the near future even at the basin scale. The analysis of possible mitigation scenarios reveals that the impact of global change may be counteracted by the decrease of irrigated areas. Furthermore, the comparison between a non-monetary (S:D ratio) and a monetary (water price) valuation metrics reveals that the S:D ratio provides similar values and might be therefore used as a spatially explicit metric to valuate the ecosystem service water provisioning. © 2013.

  3. Impacts of Mega-droughts on Water and Food Security in the Indo-Gangetic Plains: A Paleoclimate Scenario Analysis

    NASA Astrophysics Data System (ADS)

    Zhu, T.; Pitois, G.; Ringler, C.; Wang, D.; Rosegrant, M. W.

    2014-12-01

    Spanning over Pakistan, northern India, Nepal, and Bangladesh, the Indo-Gangetic Plains (IGP) is the home of several hundred million people and the "bread basket" for much of South Asia. The flat terrain, fertile soils, and favorable climate of the IGP make it agriculturally productive. However prolonged droughts caused by consecutive monsoon failures can seriously affect crop production and social wellbeing, in particular for the eastern part of the plains where agriculture remains largely rain-fed. Severe droughts were observed in the IGP historically, and recent paleoclimate studies reveal that more severe and long-lasting "mega-droughts" had happened in the distant past. Agricultural losses from major droughts can dramatically affect food systems and increase the vulnerability of resource-poor people given the delicate balance between food supply and demand under growing natural resource scarcity. To estimate the potential impacts of "mega-droughts" on the water and food systems in the IGP, we develop worst-case drought scenarios through inverse modeling of tree-ring-based PDSI reconstruction that covers the period 1300-1899 (A.D.), and analyze these historic mega-drought scenarios using IFPRI's IMPACT global water and food projections model. The base year of the IMPACT model is parameterized using socioeconomic and engineering data that reflect today's water management and infrastructure, agricultural technologies, population, income, and market institutions. The base year simulation is validated against observations to ensure model fidelity. Anticipated changes of the above factors in the future out to 2050 are specified using demographic and economic growth projections and literature data. Model simulation results represent the consequences of mega-droughts in the IGP given technological and socioeconomic conditions of today and in the future. We also explore policy options for increasing the resilience of water and food systems in the IGP, through scenario

  4. Fertilizer Emission Scenario Tool for crop management system scenarios

    EPA Pesticide Factsheets

    The Fertilizer Emission Scenario Tool for CMAQ is a high-end computer interface that simulates daily fertilizer application information for any gridded domain. It integrates the Weather Research and Forecasting model and CMAQ.

  5. Bronchial Aneurysms Mimicking Aortic Aneurysms: Endovascular Treatment in Two Patients

    SciTech Connect

    Vernhet, Helene; Bousquet, Claudine; Jean, Betty; Lesnik, Alvian; Durand, Gerard; Giron, Jacques; Senac, Jean Paul

    1999-05-15

    Bronchial artery dilatation and aneurysm formation is a potential complication of local inflammation, especially in bronchiectasis. When the bronchial artery has an ectopic origin from the inferior segment of the aortic arch, aneurysms may mimick aortic aneurysms. Despite this particular location, endovascular treatment is possible. We report two such aneurysms that were successfully embolized with steel coils.

  6. Cutaneous lymphoid hyperplasia mimicking cutaneous lymphoma in a hyperthyroid cat

    PubMed Central

    Snead, Elisabeth; Kerr, Moira; MacDonald, Valerie

    2013-01-01

    A 12-year-old neutered male domestic shorthair cat presented for chronic, localized, swelling and crusting of the left upper lip, weight loss, sporadic vomiting, and focal alopecia between the scapulae was diagnosed with hyperthyroidism and regional eosinophilic lymphadenitis. Treatment with methimazole exacerbated an underlying hypersensitivity disorder leading to marked generalized lymphadenopathy that histologically mimicked lymphoma. PMID:24155419

  7. Retroperitoneal bronchogenic cyst mimicking hydatid liver: a case report.

    PubMed

    Parray, Fazl Q; Sherwani, Afak Yusuf; Dangroo, Sajad Ahmad; Bisati, Rafia Aziz; Malik, Nighat Shaffi

    2012-01-01

    Bronchogenic cysts frequently occur in the mediastinum. They may be rarely encountered in the abdomen and retroperitoneum. Bronchogenic cysts can in fact mimic hydatid cysts. We report a case of retroperitoneal bronchogenic cyst below the right hemidiaphragm mimicking a hydatid cyst of the liver in a 30-year-old female.

  8. Retroperitoneal Bronchogenic Cyst Mimicking Hydatid Liver: A Case Report

    PubMed Central

    Parray, Fazl Q.; Sherwani, Afak Yusuf; Dangroo, Sajad Ahmad; Bisati, Rafia Aziz; Malik, Nighat Shaffi

    2012-01-01

    Bronchogenic cysts frequently occur in the mediastinum. They may be rarely encountered in the abdomen and retroperitoneum. Bronchogenic cysts can in fact mimic hydatid cysts. We report a case of retroperitoneal bronchogenic cyst below the right hemidiaphragm mimicking a hydatid cyst of the liver in a 30-year-old female. PMID:22606600

  9. Organic diseases mimicking acral lick dermatitis in six dogs.

    PubMed

    Denerolle, Philippe; White, Stephen D; Taylor, Tara S; Vandenabeele, Sophie I J

    2007-01-01

    Acral lick dermatitis ("lick granuloma") in dogs is often thought to have a behavioral etiology. However, other diseases may cause lesions on the distal legs, mimicking acral lick dermatitis. In this report, six dogs were presented with acral lick dermatitis-like lesions from different underlying causes-namely lymphoma, an orthopedic pin, deep pyoderma, mast cell tumor, leishmaniasis, and (presumptive) sporotrichosis.

  10. [Ectopic pancreas mimicking advanced gastric malignancy--case report].

    PubMed

    Zawada, Iwona; Lewosiuk, Agnieszka; Hnatyszyn, Krzysztof; Patalan, Michał; Woyke, Stanisław; Kostyrka, Roman; Marlicz, Krzysztof; Starzyńska, Teresa

    2012-04-01

    Ectopic pancreas is the most common type of ectopic tissue in gastrointestinal tract. It is typically asymptomatic, presenting as a small submucosal lesion in prepyloric region of stomach. The diagnosis is usually incidental, during gastroscopy. The patient with symptomatic heterotropic pancreas, mimicking gastric malignancy was described.

  11. Headache attributed to unruptured saccular aneurysm, mimicking hemicrania continua.

    PubMed

    Vikelis, Michail; Xifaras, Michail; Magoufis, Georgios; Gekas, Georgios; Mitsikostas, Dimos Dimitrios

    2005-06-01

    Unruptured cerebral arterial aneurysms most often remain asymptomatic, but they may cause headache or other symptoms or signs. We describe herewith a case of headache attributed to an unruptured internal carotid artery aneurysm, clearly mimicking the phenotype of hemicrania continua. Potential pathophysiological explanations and recommendations for recognition of similar cases are discussed.

  12. Cutaneous lymphoid hyperplasia mimicking cutaneous lymphoma in a hyperthyroid cat.

    PubMed

    Snead, Elisabeth; Kerr, Moira; Macdonald, Valerie

    2013-10-01

    A 12-year-old neutered male domestic shorthair cat presented for chronic, localized, swelling and crusting of the left upper lip, weight loss, sporadic vomiting, and focal alopecia between the scapulae was diagnosed with hyperthyroidism and regional eosinophilic lymphadenitis. Treatment with methimazole exacerbated an underlying hypersensitivity disorder leading to marked generalized lymphadenopathy that histologically mimicked lymphoma.

  13. Trichophyton Schoenleinii-induced widespread tinea corporis mimicking parapsoriasis.

    PubMed

    Mansouri, P; Farshi, S; Khosravi, A R; Naraghi, Z S; Chalangari, R

    2012-06-01

    We report a case of extensive tinea corporis in an 80-year-old woman on her forearms, thighs, legs, buttocks and trunk, mimicking parapsoriasis due to Trichophyton schoenleinii, without scalp involvement. Diagnosis of Trichophyton schoenleinii was confirmed by microscopy and mycological culture specimens.

  14. Histoplasmosis mimicking primary lung cancer or pulmonary metastases *,**

    PubMed Central

    Bello, Aline Gehlen Dall; Severo, Cecilia Bittencourt; Guazzelli, Luciana Silva; Oliveira, Flavio Mattos; Hochhegger, Bruno; Severo, Luiz Carlos

    2013-01-01

    OBJECTIVE: To describe the main clinical and radiological characteristics of patients with histoplasmosis mimicking lung cancer. METHODS: This was a retrospective descriptive study based on the analysis of the medical records of the 294 patients diagnosed with histoplasmosis between 1977 and 2011 at the Mycology Laboratory of the Santa Casa Sisters of Mercy Hospital of Porto Alegre in the city of Porto Alegre, Brazil. The diagnosis of histoplasmosis was established by culture, histopathological examination, or immunodiffusion testing (identification of M or H precipitation bands). After identifying the patients with macroscopic lesions, as well as radiological and CT findings consistent with malignancy, we divided the patients into two groups: those with a history of cancer and presenting with lesions mimicking metastases (HC group); and those with no such history but also presenting with lesions mimicking metastases (NHC group). RESULTS: Of the 294 patients diagnosed with histoplasmosis, 15 had presented with lesions mimicking primary neoplasia or metastases (9 and 6 in the HC and NHC groups, respectively). The age of the patients ranged from 13 to 67 years (median, 44 years). Of the 15 patients, 14 (93%) presented with pulmonary lesions at the time of hospitalization. CONCLUSIONS: The clinical and radiological syndrome of neoplastic disease is not confined to malignancy, and granulomatous infectious diseases must therefore be considered in the differential diagnosis. PMID:23503487

  15. Rectal diverticulitis mimicking rectal carcinoma with intestinal obstruction: case report.

    PubMed

    Özçelik, Ümit; Bircan, Hüseyin Yüce; Eren, Eryiğit; Demiralay, Ebru; Işıklar, İclal; Demirağ, Alp; Moray, Gökhan

    2015-01-01

    Although diverticular disease of the colon is common, the occurrence of rectal diverticula is extremely rare with only sporadic reports in the literature since 1911. Symptomatic rectal diverticula are seen even less frequently, and surgical intervention is needed for only complicated cases. Here we report the case of a 63-year-old woman presenting with rectal diverticulitis mimicking rectal carcinoma with intestinal obstruction.

  16. Diffuse Large B Cell Lymphoma Mimicking Granulomatosis with Polyangiitis

    PubMed Central

    Horowitz, Netanel; Ben-Itzhak, Ofer; Braun-Moscovici, Yolanda

    2016-01-01

    In a patient with systemic multiorgan disease with overlapping features, the differential diagnosis included infectious diseases, malignancies, and systemic autoimmune or inflammatory diseases. We present an unusual case of a young male with B cell lymphoma who presented with symptoms mimicking systemic vasculitis and review the existing literature. PMID:27293945

  17. The cutaneous manifestations and common mimickers of physical child abuse.

    PubMed

    Mudd, Shawna S; Findlay, Jeanne S

    2004-01-01

    The cutaneous manifestations of physical child abuse are some of the most common and easily recognized forms of injury. To make an accurate assessment and diagnosis, it is important to differentiate between inflicted cutaneous injuries and mimickers of physical abuse. Likewise, an understanding of reporting guidelines helps guide practitioners in their decision making.

  18. Giant cell myocarditis mimicking idiopathic fascicular ventricular tachycardia.

    PubMed

    Weidenbach, Michael; Springer, Tina; Daehnert, Ingo; Klingel, Karin; Doll, Susanne; Janousek, Jan

    2008-02-01

    We report an adolescent with giant cell myocarditis (GCM) mimicking tachycardia-induced cardiomyopathy. His electrocardiogram (ECG) was typical for an incessant form of fascicular ventricular tachycardia. The patient rapidly deteriorated and required support using extracorporeal membrane oxygenation (ECMO). Biopsy revealed GCM with massive myocyte necrosis. He was successfully heart transplanted 6 days after admission.

  19. Mechanisms for attenuation in cancellous-bone-mimicking phantoms.

    PubMed

    Wear, Keith A

    2008-11-01

    Broadband ultrasound attenuation (BUA) in cancellous bone is useful for prediction of osteoporotic fracture risk, but its causes are not well understood. To investigate attenuation mechanisms, 9 cancellous-bone-mimicking phantoms containing nylon filaments (simulating bone trabeculae) embedded within soft-tissue-mimicking fluid (simulating marrow) were interrogated. The measurements of frequency-dependent attenuation coefficient had 3 separable components: 1) a linear (with frequency) component attributable to absorption in the soft-tissue-mimicking fluid, 2) a quasilinear (with frequency) component, which may include absorption in and longitudinal-shear mode conversion by the nylon filaments, and 3) a nonlinear (with frequency) component, which may be attributable to longitudinal-longitudinal scattering by the nylon filaments. The slope of total linear (with frequency) attenuation coefficient (sum of components #1 and #2) versus frequency was found to increase linearly with volume fraction, consistent with reported measurements on cancellous bone. Backscatter coefficient measurements in the 9 phantoms supported the claim that the nonlinear (with frequency) component of attenuation coefficient (component #3) was closely associated with longitudinal-longitudinal scattering. This work represents the first experimental separation of these 3 components of attenuation in cancellous bone-mimicking phantoms.

  20. Mimicking shear zones: An example from Wadi Filk, Jordan

    NASA Astrophysics Data System (ADS)

    Meyer, Sven Erik; Passchier, Cees; Jarrar, Ghaleb H.; Ghanem, Hind; Yaseen, Najel

    2017-05-01

    Ductile shear zones can develop in at least two ways: (1) a nucleus can grow laterally by free propagation into undeformed host rock, like most faults or joints; (2) the zone may nucleate and grow on or in a planar discontinuity and mimick its orientation. Most small-scale ductile shear zones are mimicking zones, but large-scale ductile shear zones could be free-propagating. The Wadi Filk mylonite zone in Jordan is a two km long, ten meter wide mylonite zone flanked by ultramylonite zones, developed in undeformed Neoproterozoic porphyritic monzogranite. Since mineral and major element composition of mylonite and monzogranite are identical, the structure seems to have formed by free propagation. Only detailed observations of the microstructure and trace element chemistry of the mylonite indicate that it is mimicking a precursor rhyolitic dyke. The Wadi Filk mylonite zone shows that even km-scale ductile shear zones can be mimicking dykes. Fine-grained chilled margins of dykes can act as a nucleus of ultramylonite formation.

  1. Osteoid osteoma of the radial styloid mimicking de quervain tenosynovitis.

    PubMed

    Chloros, George D; Themistocleous, George S; Papagelopoulos, Panayiotis J; Khaldi, Lubna; Efstathopoulos, Dimitrios G; Soucacos, Panayotis N

    2007-10-01

    A very unusual location of osteoid osteoma arising in the radial styloid is presented, which strongly mimicked de Quervain tenosynovitis, thereby resulting in the patient undergoing an additional unnecessary operation and a substantial delay of more than 2 years in diagnosis.

  2. Sudden early-morning awakening impairs immediate tactical planning in a changing 'emergency' scenario.

    PubMed

    Horne, Jim; Moseley, Robert

    2011-06-01

    This was a realistic military-type exercise assessing unexpected, abrupt early-morning awakening effects on immediate 'executive function' and the ability to comprehend and deal with a sudden emergency under a changing situation. Twenty (average age 21years) healthy, highly motivated junior officer reservists were assigned randomly to two equal, independent groups, unforewarned as to what would happen. The experimental group was woken abruptly at 03:00h (<3h sleep) and confronted immediately with a 'paper exercise' of an enemy attack, requiring a feasible plan of engagement with minimal loss of resources, to be completed within 15min. A control group slept until 07:30h; they were then presented with the identical emergency 1h later. Participants worked individually, under time pressure, receiving written information, map and other details, all containing relevant, irrelevant and misleading information. Halfway through, they were given (unexpectedly) a critical update necessitating a change of tactics. Performance was scored blind by instructors, under five categories. Eight of the experimental group versus three controls failed overall, with significant group differences on three specific categories relying on flexible decision-making: 'identification of available cover', 'use of available assets' and 'extraction of relevant from irrelevant information'. Other, logical and highly trained skills were unimpaired. Ours was a 'worst case scenario', combining short sleep, circadian 'trough' and sleep inertia, all of which differentiated the two groups, unlike typical laboratory studies. Nevertheless, it was relevant to real-life situations involving highly motivated, trained individuals making critical innovative decisions in the early morning versus the normal waking day. © 2010 European Sleep Research Society.

  3. Alternative scenarios utilizing nonterrestrial resources

    NASA Technical Reports Server (NTRS)

    Eldred, Charles H.; Roberts, Barney B.

    1992-01-01

    A collection of alternative scenarios that are enabled or substantially enhanced by the utilization of nonterrestrial resources is provided. We take a generalized approach to scenario building so that our report will have value in the context of whatever goals are eventually chosen. Some of the topics covered include the following: lunar materials processing; asteroid mining; lunar resources; construction of a large solar power station; solar dynamic power for the space station; reduced gravity; mission characteristics and options; and tourism.

  4. Scenario-Based Tsunami Hazard Assessment from Earthquake and Landslide Sources for Eastern Sicily, Italy

    NASA Astrophysics Data System (ADS)

    Tinti, S.; Armigliato, A.; Pagnoni, G.; Paparo, M. A.; Zaniboni, F.

    2016-12-01

    Eastern Sicily was theatre of the most damaging tsunamis that ever struck Italy, such as the 11 January 1693 and the 28 December 1908 tsunamis. Tectonic studies and paleotsunami investigations extended historical records of tsunami occurrence back of several thousands of years. Tsunami sources relevant for eastern Sicily are both local and remote, the latter being located in the Ionian Greece and in the Western Hellenic Arc. Here in 365 A.D. a large earthquake generated a tsunami that was seen in the whole eastern and central Mediterranean including the Sicilian coasts. The objective of this study is the evaluation of tsunami hazard along the coast of eastern Sicily, central Mediterranean, Italy via a scenario-based technique, which has been preferred to the PTHA approach because, when dealing with tsunamis induced by landslides, uncertainties are usually so large to undermine the PTHA results. Tsunamis of earthquake and landslide origin are taken into account for the entire coast of Sicily, from the Messina to the Siracusa provinces. Landslides are essentially local sources and can occur underwater along the unstable flanks of the Messina Straits or along the steep slopes of the Hyblaean-Malta escarpment. The method is based on a two-step procedure. After a preliminary step where very many earthquake and landslide sources are taken into account and tsunamis are computed on a low-resolution grid, the worst-case scenarios are selected and tsunamis are simulated on a finer-resolution grid allowing for a better calculation of coastal wave height and tsunami penetration. The final result of our study is given in the form of aggregate fields computed from individual scenarios. Also interesting is the contribution of the various tsunami sources in different localities along the coast. It is found that the places with the highest level of hazard are the low lands of La Playa south of Catania and of the Bay of Augusta, which is in agreement also with historical

  5. Medical Scenarios Relevant to Spaceflight

    NASA Technical Reports Server (NTRS)

    Bacal, Kira; Hurs, Victor; Doerr, Harold

    2004-01-01

    The Medical Operational Support Team (MOST) was tasked by the JSC Space Medicine and Life Sciences Directorate (SLSD) to incorporate medical simulation into 1) medical training for astronaut-crew medical officers (CMO) and medical flight control teams and 2) evaluations of procedures and resources required for medical care aboard the International Space Station (ISS). Development of evidence-based medical scenarios that mimic the physiology observed during spaceflight will be needed for the MOST to complete these two tasks. The MOST used a human patient simulator, the ISS-like resources in the Medical Simulation Laboratory (MSL), and evidence from space operations, military operations and medical literature to develop space relevant medical scenarios. These scenarios include conditions concerning airway management, Advanced Cardiac Life Support (ACLS) and mitigating anaphylactic symptoms. The MOST has used these space relevant medical scenarios to develop a preliminary space medical training regimen for NASA flight surgeons, Biomedical Flight Controllers (Biomedical Engineers; BME) and CMO-analogs. This regimen is conducted by the MOST in the MSL. The MOST has the capability to develop evidence-based space-relevant medical scenarios that can help SLSD I) demonstrate the proficiency of medical flight control teams to mitigate space-relevant medical events and 2) validate nextgeneration medical equipment and procedures for space medicine applications.

  6. Scenario-based tsunami risk assessment using a static flooding approach and high-resolution digital elevation data: An example from Muscat in Oman

    NASA Astrophysics Data System (ADS)

    Schneider, Bastian; Hoffmann, Gösta; Reicherter, Klaus

    2016-04-01

    Knowledge of tsunami risk and vulnerability is essential to establish a well-adapted Multi Hazard Early Warning System, land-use planning and emergency management. As the tsunami risk for the coastline of Oman is still under discussion and remains enigmatic, various scenarios based on historical tsunamis were created. The suggested inundation and run-up heights were projected onto the modern infrastructural setting of the Muscat Capital Area. Furthermore, possible impacts of the worst-case tsunami event for Muscat are discussed. The approved Papathoma Tsunami Vulnerability Assessment Model was used to model the structural vulnerability of the infrastructure for a 2 m tsunami scenario, depicting the 1945 tsunami and a 5 m tsunami in Muscat. Considering structural vulnerability, the results suggest a minor tsunami risk for the 2 m tsunami scenario as the flooding is mainly confined to beaches and wadis. Especially traditional brick buildings, still predominant in numerous rural suburbs, and a prevalently coast-parallel road network lead to an increased tsunami risk. In contrast, the 5 m tsunami scenario reveals extensively inundated areas and with up to 48% of the buildings flooded, and therefore consequently a significantly higher tsunami risk. We expect up to 60000 damaged buildings and up to 380000 residents directly affected in the Muscat Capital Area, accompanied with a significant loss of life and damage to vital infrastructure. The rapid urbanization processes in the Muscat Capital Area, predominantly in areas along the coast, in combination with infrastructural, demographic and economic growth will additionally increase the tsunami risk and therefore emphasizes the importance of tsunami risk assessment in Oman.

  7. Alternative Geothermal Power Production Scenarios

    DOE Data Explorer

    Sullivan, John

    2014-03-14

    The information given in this file pertains to Argonne LCAs of the plant cycle stage for a set of ten new geothermal scenario pairs, each comprised of a reference and improved case. These analyses were conducted to compare environmental performances among the scenarios and cases. The types of plants evaluated are hydrothermal binary and flash and Enhanced Geothermal Systems (EGS) binary and flash plants. Each scenario pair was developed by the LCOE group using GETEM as a way to identify plant operational and resource combinations that could reduce geothermal power plant LCOE values. Based on the specified plant and well field characteristics (plant type, capacity, capacity factor and lifetime, and well numbers and depths) for each case of each pair, Argonne generated a corresponding set of material to power ratios (MPRs) and greenhouse gas and fossil energy ratios.

  8. Haunted Quantum Entanglement: Two Scenarios

    NASA Astrophysics Data System (ADS)

    Snyder, Douglas

    2010-04-01

    Two haunted quantum entanglement scenarios are proposed that are very close to the haunted measurement scenario in that: 1) the entity that is developing as a which-way marker is effectively restored to its state prior to its being fixed as a w-w marker, and 2) the entity for which the developing w-w marker provides information is restored to its state before it interacted with the entity which subsequent to the interaction begins developing as a w-w marker. In the hqe scenarios, the loss of developing w-w information through 1 relies on the loss of a developing entanglement. In scenario 1, the photon initially emitted in one of two micromaser cavities and developing into a w-w marker is effectively lost through the injection of classical microwave radiation into both of the microwave cavities after the atom initially emits the photon into one of the micromaser cavities, exits the cavity system, and before this atom reaches the 2 slit screen. The atom is restored in both of the two new scenarios to its original state before it emitted a photon by an rf coil situated at the exit of the micromaser cavity system. In scenario 2, the cavity system and everything from the atom source forward to the cavity system is enclosed in an evacuated box. After the atom that emits the photon exits the cavity system and before it reaches the 2 slit screen, the cavity system opens (and the photon escapes in the evacuated box) and then the box is opened and the photon escapes into the environment.

  9. Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants

    NASA Astrophysics Data System (ADS)

    Ulery, Bret D.; Petersen, Latrisha K.; Phanse, Yashdeep; Kong, Chang Sun; Broderick, Scott R.; Kumar, Devender; Ramer-Tait, Amanda E.; Carrillo-Conde, Brenda; Rajan, Krishna; Wannemuehler, Michael J.; Bellaire, Bryan H.; Metzger, Dennis W.; Narasimhan, Balaji

    2011-12-01

    An opportunity exists today for cross-cutting research utilizing advances in materials science, immunology, microbial pathogenesis, and computational analysis to effectively design the next generation of adjuvants and vaccines. This study integrates these advances into a bottom-up approach for the molecular design of nanoadjuvants capable of mimicking the immune response induced by a natural infection but without the toxic side effects. Biodegradable amphiphilic polyanhydrides possess the unique ability to mimic pathogens and pathogen associated molecular patterns with respect to persisting within and activating immune cells, respectively. The molecular properties responsible for the pathogen-mimicking abilities of these materials have been identified. The value of using polyanhydride nanovaccines was demonstrated by the induction of long-lived protection against a lethal challenge of Yersinia pestis following a single administration ten months earlier. This approach has the tantalizing potential to catalyze the development of next generation vaccines against diseases caused by emerging and re-emerging pathogens.

  10. A patient with plaque type morphea mimicking systemic lupus erythematosus.

    PubMed

    Wardhana; Datau, E A

    2015-04-01

    Morphea is an uncommon connective tissue disease with the most prominent feature being thickening or fibrosis of the dermal without internal organ involvement. It is also known as a part of localized scleroderma. Based on clinical presentation and depth of tissue involvement, morphea is classified into several forms, and about two thirds of adults with morphea have plaque type. Overproduction of collagen production by fibroblast is the cause of abnormality in morphea, and the hyperactivity mechanism of fibroblast is still unknown, although there are several mechanisms already proposed. Plaque type morphea is actually a benign and self limited. Plaque type morphea that mimicking systemic lupus erythematosus in clinical appearance, such as alopecia and oral mucosal ulcers, is uncommon. A case of plaque type morphea mimicking systemic lupus erythematosus in a 20 year old woman was discussed. The patient was treated with local and systemic immunosuppressant and antioxydant. The patient's condition is improved without any significant side effects.

  11. Granuloma inguinale mimicking as squamous cell carcinoma of penis

    PubMed Central

    Pilani, Abhishek; Vora, Rita; Anjaneyan, Gopikrishnan

    2014-01-01

    Granuloma inguinale (GI) is an acquired chronic, slowly progressive, mildly contagious disease of venereal origin, characterized by granulomatous ulceration of the genitalia and neighboring sites, with little or no tendency to spontaneous healing caused by Klebsiella (Calymmatobacterium) granulomatis. A 55-year-old male presented with fissured, foul smelling, fungating growth over prepuce with phimosis mimicking squamous cell carcinoma (SCC) without lymphadenopathy. It started with painless papulonodular showed pseudoepitheliomatous hyperplasia, infiltration in dermis, acanthosis and vacuolated macrophages suggestive of GI and not showing any histopathological features of SCC. Patient was successfully treated by giving cotrimoxazole twice a day for 21 days. Here, we presented a case of GI mimicking SCC of penis, which was diagnosed on basis of histopathology and treated with excision followed by medical therapy with cotrimoxazole. PMID:24958990

  12. The stiffening of arteries by the tissue-mimicking gelatin.

    PubMed

    Zhang, Xiaoming; Greenleaf, James F

    2006-08-01

    Pulse wave velocity (PWV) is widely used for estimating the stiffness of an artery. PWV is measured by the time of travel of the "foot" of the pressure wave over a known distance. This technique has a low time resolution and is an average measurement of artery stiffness between the two measuring sites. The elastic modulus of the artery can be estimated with PWV, but the surrounding tissue effects are not considered. In this paper an external short pulse wave is generated noninvasively in the arterial wall by the radiation force of ultrasound. The pulse wave velocity in the artery is measured by a scanning technique with high-time resolution. The effect of tissue-mimicking gelatin on the artery is analyzed by measuring the wave velocity of the artery without and embedded in gelatin. It is found that the tissue-mimicking gelatin significantly stiffens the rubber tube and the artery if they are embedded in gelatin.

  13. An exposimetry system using tissue-mimicking liquid.

    PubMed

    Stiles, Timothy A; Madsen, Ernest L; Frank, Gary R

    2008-01-01

    Acoustic output measurements of diagnostic ultrasound scanners are currently performed in water and derated to approximate in situ values. The derating scheme ignores nonlinear propagation of sound waves and has been shown in previous numerical and experimental studies to tend to underestimate relevant pressure and intensity values in tissue mimicking media. This work describes an alternative method, which uses a tissue-mimicking liquid with attenuation coefficient slope of 0.3 dB/cm/MHz, speed of sound of 1,540 m/s and nonlinearity parameter B/A of 7.5. The acoustic properties of this liquid are stable for at least 2 y after production. Initial results using a single M-mode configuration are presented. These results confirm that derating can significantly underestimate the pulse intensity integral and peak rarefactional pressure.

  14. Tsunami hazard potential for the equatorial southwestern Pacific atolls of Tokelau from scenario-based simulations

    NASA Astrophysics Data System (ADS)

    Orpin, Alan R.; Rickard, Graham J.; Gerring, Peter K.; Lamarche, Geoffroy

    2016-05-01

    Devastating tsunami over the last decade have significantly heightened awareness of the potential consequences and vulnerability of low-lying Pacific islands and coastal regions. Our appraisal of the potential tsunami hazard for the atolls of the Tokelau Islands is based on a tsunami source-propagation-inundation model using Gerris Flow Solver, adapted from the companion study by Lamarche et al. (2015) for the islands of Wallis and Futuna. We assess whether there is potential for tsunami flooding on any of the village islets from a selection of 14 earthquake-source experiments. These earthquake sources are primarily based on the largest Pacific earthquakes of Mw ≥ 8.1 since 1950 and other large credible sources of tsunami that may impact Tokelau. Earthquake-source location and moment magnitude are related to tsunami-wave amplitudes and tsunami flood depths simulated for each of the three atolls of Tokelau. This approach yields instructive results for a community advisory but is not intended to be fully deterministic. Rather, the underlying aim is to identify credible sources that present the greatest potential to trigger an emergency response. Results from our modelling show that wave fields are channelled by the bathymetry of the Pacific basin in such a way that the swathes of the highest waves sweep immediately northeast of the Tokelau Islands. Our limited simulations suggest that trans-Pacific tsunami from distant earthquake sources to the north of Tokelau pose the most significant inundation threat. In particular, our assumed worst-case scenario for the Kuril Trench generated maximum modelled-wave amplitudes in excess of 1 m, which may last a few hours and include several wave trains. Other sources can impact specific sectors of the atolls, particularly distant earthquakes from Chile and Peru, and regional earthquake sources to the south. Flooding is dependent on the wave orientation and direct alignment to the incoming tsunami. Our "worst-case" tsunami

  15. [Femicides: concepts, types and scenarios].

    PubMed

    Meneghel, Stela Nazareth; Portella, Ana Paula

    2017-09-01

    This text is a theoretical essay that discusses the concepts, types and scenarios of feminicides, and presents some proposals for the prevention of these premature, unjust and avoidable deaths. The text revisits the original concept of femicide proposed by Diana Russell and Jane Caputti and shows new and old scenarios where these crimes occur. It points to patriarchy, understood as being a hierarchical system of power between men and women, as one of the main determinants of these deaths. It ends by presenting actions and proposals to prevent and combat these gender crimes.

  16. Testicular Schistosomiasis Mimicking Malignancy in a Child: A Case Report.

    PubMed

    Ekenze, Sebastian O; Modekwe, Victor O; Nzegwu, Martin A; Ekpemo, Samuel C; Ezomike, Uchechukwu O

    2015-08-01

    Schistosomiasis is an important communicable disease in the developing world. However, testicular schistosomiasis is an extremely rare condition. We report a case of testicular schistosomiasis mimicking testicular tumour in a 13 year old who presented with huge unilateral testicular mass. The dilemma encountered in the diagnosis and treatment of this child is presented to highlight the need for high index of suspicion of this pathology in children with testicular mass presenting from schistosomiasis-endemic areas.

  17. Mimicking biological functionality with polymers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Green, Jordan J.; Elisseeff, Jennifer H.

    2016-12-01

    The vast opportunities for biomaterials design and functionality enabled by mimicking nature continue to stretch the limits of imagination. As both biological understanding and engineering capabilities develop, more sophisticated biomedical materials can be synthesized that have multifaceted chemical, biological and physical characteristics designed to achieve specific therapeutic goals. Mimicry is being used in the design of polymers for biomedical applications that are required locally in tissues, systemically throughout the body, and at the interface with tissues.

  18. Intracranial subdural empyema mimicking a recurrent chronic subdural hematoma

    PubMed Central

    Doan, Ninh; Patel, Mohit; Nguyen, Ha Son; Mountoure, Andrew; Shabani, Saman; Gelsomino, Michael; Janich, Karl; Kurpad, Shekar

    2016-01-01

    Intracranial subdural empyema (ISDE) is a life-threatening condition. The risk for ISDE increases in patients that have undergone prior intracranial procedures. The non-specificity in its clinical presentation often makes ISDE difficult to diagnose. Here, we present a rare case of ISDE mimicking a recurrent chronic subdural hematoma, emphasizing the significance of obtaining early magnetic resonance images of the brain for early diagnosis and treatment to achieve the optimal outcome. PMID:27651110

  19. Cartilage Delamination Flap Mimicking a Torn Medial Meniscus

    PubMed Central

    Bin Abd Razak, Hamid Rahmatullah; Amit Kanta, Mitra

    2016-01-01

    We report a case of a chondral delamination lesion due to medial parapatellar plica friction syndrome involving the medial femoral condyle. This mimicked a torn medial meniscus in clinical and radiological presentation. Arthroscopy revealed a chondral delamination flap, which was debrided. Diagnosis of chondral lesions in the knee can be challenging. Clinical examination and MRI have good accuracy for diagnosis and should be used in tandem. Early diagnosis and treatment of chondral lesions are important to prevent progression to early osteoarthritis. PMID:28070434

  20. Localized IgG4-related Cholecystitis Mimicking Gallbladder Cancer.

    PubMed

    Inoue, Tadahisa; Okumura, Fumihiro; Mizushima, Takashi; Nishie, Hirotada; Iwasaki, Hiroyasu; Anbe, Kaiki; Ozeki, Takanori; Kachi, Kenta; Fukusada, Shigeki; Suzuki, Yuta; Watanabe, Kazuko; Sano, Hitoshi

    2015-01-01

    We encountered a case of localized IgG4-cholecystitis mimicking gallbladder cancer with focal/segmental type1 autoimmune pancreatitis (AIP). In this case, we were unable to exclude a diagnosis of gallbladder cancer and thus performed radical cholecystectomy. Type1 AIP is often associated with gallbladder lesions, accompanied by generally diffuse, circumferential thickening of the gallbladder wall. Although localized IgG4-related cholecystitis is extremely rare, differentiating this condition from gallbladder cancer is often very difficult.

  1. Mimicking Classical Conditioning Based on a Single Flexible Memristor.

    PubMed

    Wu, Chaoxing; Kim, Tae Whan; Guo, Tailiang; Li, Fushan; Lee, Dea Uk; Yang, J Joshua

    2017-03-01

    The mimicking of classical conditioning, including acquisition, extinction, recovery, and generalization, can be efficiently achieved by using a single flexible memristor. In particular, the experiment of Pavlov's dog is successfully demonstrated. This demonstration paves the way for reproducing advanced neural processes and provides a frontier approach to the design of artificial-intelligence systems with dramatically reduced complexity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. A giant ancient schwannoma mimicking an adnexal mass

    PubMed Central

    Karaköse, Oktay; Pülat, Hüseyin; Oğuz, Serhat; Zihni, İsmail; Özçelik, Kazım Çağlar; Yalta, Tülin Deniz; Eken, Hüseyin

    2016-01-01

    Abstract Introduction: Ancient schwannoma is a rare tumor of the peripheral nerve sheath. As degenerative properties are defined histologically, it can be wrongly interpreted as malignant. Case presentation: The case presented here is of a giant ancient schwannoma with a pelvic retroperitoneal location, which was mimicking an adnexal mass. Conclusion: In the rarely seen cases in the retroperitoneum, it may reach very large dimensions. PMID:27472696

  3. Reactive arthritis mimicking inflammatory bowel disease arthritis: a challenging diagnosis.

    PubMed

    Trabulo, D; Mangualde, J; Cremers, I; Oliveira, A P

    2014-01-01

    Reactive arthritis comprises a subgroup of infection-associated arthritis which occurs after genitourinary or gastrointestinal tract infection in genetically susceptible hosts. Studies have proposed Salmonella, Shigella or Yersinia infection as the microorganisms responsible for the post-dysenteric form. The human leukocyte antigen (HLA)-B27 is a well recognised best-known predisposing factor. We report a case of HLA-B27-associated reactive arthritis after Salmonella goldcoast enteritis, mimicking inflammatory bowel disease arthritis.

  4. Osteofibrous dysplasia of clavicle clinically mimicking chronic osteomyelitis

    PubMed Central

    Gopinathan, Nirmal Raj; Prakash, Mahesh; Saibaba, Balaji; Das, Ashim

    2016-01-01

    Osteofibrous dysplasia or ossifying fibroma is an uncommon benign fibro-osseous lesion of childhood, commonly described in the maxilla and the mandible. Among long bones, it usually presents in the tibia as a painless swelling or anterior bowing. Ossifying fibroma of clavicle has never been reported in English literature, to the best of our knowledge. Here, we would like to present an unusual case of osteofibrous dysplasia of clavicle clinically mimicking chronic osteomyelitis. PMID:27413281

  5. Regional bone change in intramuscular haemangioma mimicking primary bone tumour.

    PubMed

    Shikhare, Sumer; Chacko, Julio K; Chuah, Khoon L

    2015-04-01

    Intramuscular haemangiomas are benign soft-tissue tumours, commonly located in the extremities. We present a right-leg intramuscular haemangioma with florid periosteal reaction in adjacent tibia, mimicking a primary bone tumour. Plain radiograph and magnetic resonance imaging features are illustrated with the surgical and histopathological findings. Radiologists need to be familiar with reactive bone changes secondary to deep-seated intramuscular haemangiomas to avoid potential misdiagnosis.

  6. Addison's Disease Mimicking as Acute Pancreatitis: A Case Report.

    PubMed

    Chaudhuri, Sayani; Rao, Karthik N; Patil, Navin; Ommurugan, Balaji; Varghese, George

    2017-04-01

    Over past two decades there has been significant improvement in medical field in elucidating the underlying pathophysiology and genetics of Addison's disease. Adrenal insufficiency (Addison's disease) is a rare disease with an incidence of 0.8/100,000 cases. The diagnosis may be delayed if the clinical presentation mimics a gastrointestinal disorder or psychiatric illness. We report a case of Addison's disease presenting as acute pain in abdomen mimicking clinical presentation of acute pancreatitis.

  7. Heparin-Mimicking Polymers: Synthesis and Biological Applications.

    PubMed

    Paluck, Samantha J; Nguyen, Thi H; Maynard, Heather D

    2016-11-14

    Heparin is a naturally occurring, highly sulfated polysaccharide that plays a critical role in a range of different biological processes. Therapeutically, it is mostly commonly used as an injectable solution as an anticoagulant for a variety of indications, although it has also been employed in other forms such as coatings on various biomedical devices. Due to the diverse functions of this polysaccharide in the body, including anticoagulation, tissue regeneration, anti-inflammation, and protein stabilization, and drawbacks of its use, analogous heparin-mimicking materials are also widely studied for therapeutic applications. This review focuses on one type of these materials, namely, synthetic heparin-mimicking polymers. Utilization of these polymers provides significant benefits compared to heparin, including enhancing therapeutic efficacy and reducing side effects as a result of fine-tuning heparin-binding motifs and other molecular characteristics. The major types of the various polymers are summarized, as well as their applications. Because development of a broader range of heparin-mimicking materials would further expand the impact of these polymers in the treatment of various diseases, future directions are also discussed.

  8. Dengue fever mimicking acute appendicitis: A case report.

    PubMed

    McFarlane, M E C; Plummer, J M; Leake, P A; Powell, L; Chand, V; Chung, S; Tulloch, K

    2013-01-01

    Dengue fever is an acute viral disease, which usually presents as a mild febrile illness. Patients with severe disease present with dengue haemorrhagic fever or dengue toxic shock syndrome. Rarely, it presents with abdominal symptoms mimicking acute appendicitis. We present a case of a male patient presenting with right iliac fossa pain and suspected acute appendicitis that was later diagnosed with dengue fever following a negative appendicectomy. A 13-year old male patient presented with fever, localized right-sided abdominal pain and vomiting. Abdominal ultrasound was not helpful and appendicectomy was performed due to worsening abdominal signs and an elevated temperature. A normal appendix with enlarged mesenteric nodes was found at surgery. Complete blood count showed thrombocytopenia with leucopenia. Dengue fever was now suspected and confirmed by IgM enzyme-linked immunosorbent assay against dengue virus. This unusual presentation of dengue fever mimicking acute appendicitis should be suspected during viral outbreaks and in patients with atypical symptoms and cytopenias on blood evaluation in order to prevent unnecessary surgery. This case highlights the occurrence of abdominal symptoms and complications that may accompany dengue fever. Early recognition of dengue fever mimicking acute appendicitis will avoid non-therapeutic operation and the diagnosis may be aided by blood investigations indicating a leucopenia, which is uncommon in patients with suppurative acute appendicitis. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Heparin-Mimicking Polymers: Synthesis and Biological Applications

    PubMed Central

    2016-01-01

    Heparin is a naturally occurring, highly sulfated polysaccharide that plays a critical role in a range of different biological processes. Therapeutically, it is mostly commonly used as an injectable solution as an anticoagulant for a variety of indications, although it has also been employed in other forms such as coatings on various biomedical devices. Due to the diverse functions of this polysaccharide in the body, including anticoagulation, tissue regeneration, anti-inflammation, and protein stabilization, and drawbacks of its use, analogous heparin-mimicking materials are also widely studied for therapeutic applications. This review focuses on one type of these materials, namely, synthetic heparin-mimicking polymers. Utilization of these polymers provides significant benefits compared to heparin, including enhancing therapeutic efficacy and reducing side effects as a result of fine-tuning heparin-binding motifs and other molecular characteristics. The major types of the various polymers are summarized, as well as their applications. Because development of a broader range of heparin-mimicking materials would further expand the impact of these polymers in the treatment of various diseases, future directions are also discussed. PMID:27739666

  10. Novel tissue mimicking materials for high frequency breast ultrasound phantoms.

    PubMed

    Cannon, Louise M; Fagan, Andrew J; Browne, Jacinta E

    2011-01-01

    The development and acoustical characterisation of a range of novel agar-based tissue mimicking material (TMMs) for use in clinically relevant, quality assurance (QA) and anthropomorphic breast phantoms are presented. The novel agar-based TMMs described in this study are based on a comprehensive, systematic variation of the ingredients in the International Electrotechnical Commission (IEC) TMM. A novel, solid fat-mimicking material was also developed and acoustically characterised. Acoustical characterisation was carried out using an in-house scanning acoustic macroscope at low (7.5 MHz) and high frequencies (20 MHz), using the pulse-echo insertion technique. The speeds of sound range from 1490 to 1570 m. s(-1), attenuation coefficients range from 0.1 to 0.9 dB. cm(‑1). MHz(-1) and relative backscatter ranges from 0 to -20 dB. It was determined that tissues can be mimicked in terms of independently controllable speeds of sound and attenuation coefficients. These properties make these novel TMMs suitable for use in clinically relevant QA and anthropomorphic phantoms and would potentially be useful for other high frequency applications such as intravascular and small animal imaging. Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  11. Determination of a Worst-Case Acceptor for Large-Scale Sympathetic Detonation Testing

    DTIC Science & Technology

    1994-07-01

    UNMASIlE SAR NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-69) vaicraoed b ANSI Std 13g-18 PREFACE On 30 September 1992, tht S. Army Balistic Reseah...Army Materiel Command ATI’N: AMSTA-JSK ( Armor Eng. Br.) ATTN: AMCAM Wanrn, MI 48397-5000 5001 Eienhower Ave. Alexandria. VA 22333-0001 1 Director U.S

  12. Beyond Worst-Case Analysis in Privacy and Clustering: Exploiting Explicit and Implicit Assumptions

    DTIC Science & Technology

    2013-08-01

    satisfy: svi(A) ≤ svi(B) Weyl’s inequality is a corollary of the max-min characterization of the singular values of a matrix. 11 Theorem 2.3 ( Courant ... Courant -Fischer Min-Max principle, Lindskii’s inequality follows from a generalization of the Courant -Fischer prin- ciple. Theorem 2.5 (Wielandt’s Min...30] Maria-Florina Balcan, Heiko Röglin, and Shang-Hua Teng. Agnostic clustering. In ALT, 2009. 4.2.1, 7.2.2 [31] Richard Baraniuk, Mark Davenport

  13. Modeling Mission-Specific Worst-Case Solar Energetic Particle Environments

    NASA Technical Reports Server (NTRS)

    Adam, James H., Jr.; Dietrich, William F.; Xapsos, Michael A.

    2011-01-01

    To plan and design safe and reliable space missions, it is necessary to take into account the effects of the space radiation environment. The environment during large solar energetic particle events poses the greatest challenge to missions. As a starting point for planning and design, a reference environment must be specified representing the most challenging environment to be encountered during the mission at some confidence level. The engineering challenge is then to find plans and mission design solutions that insure safe and reliable operations in this reference environment. This paper describes progress toward developing a model that provides such reference space radiation environments at user-specified confidence levels.

  14. Development of a QSAR for worst case estimates of acute toxicity of chemically reactive compounds.

    PubMed

    Freidig, A P; Dekkers, S; Verwei, M; Zvinavashe, E; Bessems, J G M; van de Sandt, J J M

    2007-05-15

    Future EU legislations enforce a fast hazard and risk assessment of thousands of existing chemicals. If conducted by means of present data requirements, this assessment will use a huge number of test animals and will be neither cost nor time effective. The purpose of the current research was to develop methods to increase the acceptability of in vitro data for classification and labelling regarding acute toxicity. For this purpose, a large existing database containing in vitro and in vivo data was analysed. For more than 300 compounds in the database, relations between in vitro cytotoxicity and rat or mouse intravenous and oral in vivo LD50 values were re-evaluated and the possibilities for definition of mechanism based chemical subclasses were investigated. A high in vitro-in vivo correlation was found for chemicals classified as irritants. This can be explained by a shared unspecific cytotoxicity of these compounds which will act as the predominant mode of action for both endpoints, irritation and acute toxicity. For this subclass, which covered almost 40% of all compounds in the database, the LD50 values after intravenous dosing could be predicted with high accuracy. A somewhat lower accuracy was found for the prediction of oral LD50 values based on in vitro cytotoxicity data. Based on this successful correlation, a classification and labelling scheme was developed, that includes a hazard based definition of the applicability domain (irritants) and a prediction of the labelling of compounds for their acute iv and oral toxicity. The scheme was tested by an external validation.

  15. Evaluation of Bias Correction Methods for "Worst-case" Selective Non-participation in NAEP

    ERIC Educational Resources Information Center

    McLaughlin, Don; Gallagher, Larry; Stancavage, Fran

    2004-01-01

    With the advent of No Child Left Behind (NCLB), the context for NAEP participation is changing. Whereas in the past participation in NAEP has always been voluntary, participation is now mandatory for some grade and subjects among schools receiving Title I funds. While this will certainly raise school-level participation rates in the mandated…

  16. The year-long unprecedented European heat and drought of 1540 - a worst case

    NASA Astrophysics Data System (ADS)

    Wetter, Oliver

    2015-04-01

    The heat waves of 2003 in Western Europe and 2010 in Russia, commonly labelled as rare climatic anomalies outside of previous experience, are often taken as harbingers of more frequent extremes in the global warming-influenced future. However, a recent reconstruction of spring-summer temperatures for WE resulted in the likelihood of significantly higher temperatures in 1540. In order to check the plausibility of this result we investigated the severity of the 1540 drought by putting forward the argument of the known soil desiccation-temperature feedback. Based on more than 300 first-hand documentary weather report sources originating from an area of 2 to 3 million km2, we show that Europe was affected by an unprecedented 11-month-long Megadrought. The estimated number of precipitation days and precipitation amount for Central and Western Europe in 1540 is significantly lower than the 100-year minima of the instrumental measurement period for spring, summer and autumn. This result is supported by independent documentary evidence about extremely low river flows and Europe-wide wild-, forestand settlement fires. We found that an event of this severity cannot be simulated by state-of-the-art climate models.

  17. Particle production in Ekpyrotic scenarios

    SciTech Connect

    Hipólito-Ricaldi, W.S.; Brandenberger, Robert; Ferreira, Elisa G.M.; Graef, L.L.

    2016-11-09

    We consider Parker particle production in the Ekpyrotic scenario (in particular in the New Ekpyrotic model) and show that the density of particles produced by the end of the phase of Ekpyrotic contraction can be sufficient to lead to a hot state of matter after the bounce. Hence, no separate reheating mechanism is necessary.

  18. Space resources. Volume 1: Scenarios

    NASA Technical Reports Server (NTRS)

    Mckay, Mary Fae (Editor); Mckay, David S. (Editor); Duke, Michael B. (Editor)

    1992-01-01

    A number of possible future paths for space exploration and development are presented. The topics covered include the following: (1) the baseline program; (2) alternative scenarios utilizing nonterrestrial resources; (3) impacts of sociopolitical conditions; (4) common technologies; and issues for further study.

  19. Future Scenarios and Environmental Education

    ERIC Educational Resources Information Center

    Kopnina, Helen

    2014-01-01

    This article explores a number of questions about visions of the future and their implications for environmental education (EE). If the future were known, what kind of actions would be needed to maintain the positive aspects and reverse the negative ones? How could these actions be translated into the aims of EE? Three future scenarios are…

  20. Ultra-Perfect Sorting Scenarios

    NASA Astrophysics Data System (ADS)

    Ouangraoua, Aïda; Bergeron, Anne; Swenson, Krister M.

    Perfection has been used as a criteria to select rearrangement scenarios since 2004. However, there is a fundamental bias towards extant species in the original definition: ancestral species are not bound to perfection. Here we develop a new theory of perfection that takes an egalitarian view of species, and apply it to the complex evolution of mammal chromosome X.

  1. Transportation scenarios for risk analysis.

    SciTech Connect

    Weiner, Ruth F.

    2010-09-01

    Transportation risk, like any risk, is defined by the risk triplet: what can happen (the scenario), how likely it is (the probability), and the resulting consequences. This paper evaluates the development of transportation scenarios, the associated probabilities, and the consequences. The most likely radioactive materials transportation scenario is routine, incident-free transportation, which has a probability indistinguishable from unity. Accident scenarios in radioactive materials transportation are of three different types: accidents in which there is no impact on the radioactive cargo, accidents in which some gamma shielding may be lost but there is no release of radioactive material, and accident in which radioactive material may potentially be released. Accident frequencies, obtainable from recorded data validated by the U.S. Department of Transportation, are considered equivalent to accident probabilities in this study. Probabilities of different types of accidents are conditional probabilities, conditional on an accident occurring, and are developed from event trees. Development of all of these probabilities and the associated highway and rail accident event trees are discussed in this paper.

  2. Modelling regional climate change and urban planning scenarios and their impacts on the urban environment in two cities with WRF-ACASA

    NASA Astrophysics Data System (ADS)

    Falk, M.; Pyles, R. D.; Marras, S.; Spano, D.; Paw U, K. T.

    2011-12-01

    The number of urban metabolism studies has increased in recent years, due to the important impact that energy, water and carbon exchange over urban areas have on climate change. Urban modeling is therefore crucial in the future design and management of cities. This study presents the ACASA model coupled to the Weather Research and Forecasting (WRF-ARW) mesoscale model to simulate urban fluxes at a horizontal resolution of 200 meters for urban areas of roughly 100 km^2. As part of the European Project "BRIDGE", these regional simulations were used in combination with remotely sensed data to provide constraints on the land surface types and the exchange of carbon and energy fluxes from urban centers. Surface-atmosphere exchanges of mass and energy were simulated using the Advanced Canopy Atmosphere Soil Algorithm (ACASA). ACASA is a multi-layer high-order closure model, recently modified to work over natural, agricultural as well as urban environments. In particular, improvements were made to account for the anthropogenic contribution to heat and carbon production. For two cities four climate change and four urban planning scenarios were simulated: The climate change scenarios include a base scenario (Sc0: 2008 Commit in IPCC), a medium emission scenario (Sc1: IPCC A2), a worst case emission scenario (Sce2: IPCC A1F1) and finally a best case emission scenario (Sce3: IPCC B1). The urban planning scenarios include different development scenarios such as smart growth. The two cities are a high latitude city, Helsinki (Finland) and an historic city, Florence (Italy). Helsinki is characterized by recent, rapid urbanization that requires a substantial amount of energy for heating, while Florence is representative of cities in lower latitudes, with substantial cultural heritage and a comparatively constant architectural footprint over time. In general, simulated fluxes matched the point observations well and showed consistent improvement in the energy partitioning over

  3. Exploring NASA Human Spaceflight and Pioneering Scenarios

    NASA Technical Reports Server (NTRS)

    Zapata, Edgar; Wilhite, Alan

    2015-01-01

    The life cycle cost analysis of space exploration scenarios is explored via a merger of (1) scenario planning, separating context and (2) modeling and analysis of specific content. Numerous scenarios are presented, leading to cross-cutting recommendations addressing life cycle costs, productivity, and approaches applicable to any scenarios. Approaches address technical and non-technical factors.

  4. A Native American exposure scenario.

    PubMed

    Harris, S G; Harper, B L

    1997-12-01

    EPA's Risk Assessment Guidance for Superfund (RAGS) and later documents provide guidance for estimating exposures received from suburban and agricultural activity patterns and lifestyles. However, these methods are not suitable for typical tribal communities whose members pursue, at least in part, traditional lifestyles. These lifestyles are derived from a long association with all of the resources in a particular region. We interviewed 35 members of a Columbia River Basin tribe to develop a lifestyle-based subsistence exposure scenario that represents a midrange exposure that a traditional tribal member would receive. This scenario provides a way to partially satisfy Executive Order 12,898 on environmental justice, which requires a specific evaluation of impacts from federal actions to peoples with subsistence diets. Because a subsistence diet is only a portion of what is important to a traditional lifestyle, we also used information obtained from the interviews to identify parameters for evaluating impacts to environmental and sociocultural quality of life.

  5. [Eukaryotes origin: a new scenario].

    PubMed

    Gonchikov, G G

    2010-01-01

    A new scenario of eukaryotes origin is proposed that explains the cytoskeleton genesis, and the genesis of cell nucleus as a "cell within cell" structure. The scenario is based on the peculiarities of spore-forming firmicutes life cycle and structure, unique for prokaryotes. It is supposed that a euryarchaeon cell was engulfed by a "bare" sporangium of an ancient polyendosporogenic and endoskeletal clostridia, bearer of microtubular endospore appendages, in the process of "abortive" forespore engulfment. In the result, a new driving force for cell transitions was formed, associated with compartmentalization of prokaryotic chromosomes. Further recombination of chromosomes induced two transitions: transformation of euryarchaeon into true cell nucleus, and transformation of microtubular endospore appendages into nucleus mitotic apparatus. In-cell reproducing organelles, such as mitochondrion and plastids, appeared later. Forthcoming full-genome studies of endoskeletal firmicutes, bearers of microtubular endospore appendages, and some eukaryotes may help to reveal the mystery of the first true nuclear cell origin.

  6. Various Tumor-Mimicking Lesions in the Musculoskeletal System: Causes and Diagnostic Approach

    PubMed Central

    Kim, Sue Yon; Ryu, Kyung Nam; Jin, Wook; Park, So Young

    2011-01-01

    Tumor-mimicking lesions in the musculoskeletal system can be defined as lesions mistaken as tumors due to the presence of palpation upon physical examination or a tumor-like appearance upon radiological examination. Moreover, tumor-mimicking lesions show diverse etiologies and anatomic locations. We illustrated the various tumor-mimicking lesions involving bone and soft tissue. In this review, the tumor-mimicking lesions were classified into those based on clinical examination and those based on radiological examination in musculoskeletal radiology. Awareness of the various causes of tumor-mimicking lesions, correctly obtaining clinical information, and the proper selection of imaging modality are important for the differentiation of tumor-mimicking lesions from true neoplasms. PMID:21430940

  7. Tsunami Hazard in La Réunion Island (SW Indian Ocean): Scenario-Based Numerical Modelling on Vulnerable Coastal Sites

    NASA Astrophysics Data System (ADS)

    Allgeyer, S.; Quentel, É.; Hébert, H.; Gailler, A.; Loevenbruck, A.

    2017-08-01

    Several major tsunamis have affected the southwest Indian Ocean area since the 2004 Sumatra event, and some of them (2005, 2006, 2007 and 2010) have hit La Réunion Island in the southwest Indian Ocean. However, tsunami hazard is not well defined for La Réunion Island where vulnerable coastlines can be exposed. This study offers a first tsunami hazard assesment for La Réunion Island. We first review the historical tsunami observations made on the coastlines, where high tsunami waves (2-3 m) have been reported on the western coast, especially during the 2004 Indian Ocean tsunami. Numerical models of historical scenarios yield results consistent with available observations on the coastal sites (the harbours of La Pointe des Galets and Saint-Paul). The 1833 Pagai earthquake and tsunami can be considered as the worst-case historical scenario for this area. In a second step, we assess the tsunami exposure by covering the major subduction zones with syntethic events of constant magnitude (8.7, 9.0 and 9.3). The aggregation of magnitude 8.7 scenarios all generate strong currents in the harbours (3-7 m s^{-1}) and about 2 m of tsunami maximum height without significant inundation. The analysis of the magnitude 9.0 events confirms that the main commercial harbour (Port Est) is more vulnerable than Port Ouest and that flooding in Saint-Paul is limited to the beach area and the river mouth. Finally, the magnitude 9.3 scenarios show limited inundations close to the beach and in the riverbed in Saint-Paul. More generally, the results confirm that for La Runion, the Sumatra subduction zone is the most threatening non-local source area for tsunami generation. This study also shows that far-field coastal sites should be prepared for tsunami hazard and that further work is needed to improve operational warning procedures. Forecast methods should be developed to provide tools to enable the authorities to anticipate the local effects of tsunamis and to evacuate the harbours in

  8. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario.

    PubMed

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-07-07

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.

  9. Designing Asteroid Impact Scenario Trajectories

    NASA Astrophysics Data System (ADS)

    Chodas, Paul

    2016-05-01

    In order to study some of the technical and geopolitical issues of dealing with an asteroid on impact trajectory, a number of hypothetical impact scenarios have been presented over the last ten years or so. These have been used, for example, at several of the Planetary Defense Conferences (PDCs), as well as in tabletop exercises with the Federal Emergency Management Agency (FEMA), along with other government agencies. The exercise at the 2015 PDC involved most of the attendees, consisted of seven distinct steps (“injects”), and with all the presentations and discussions, took up nearly 10 hours of conference time. The trajectory for the PDC15 scenario was entirely realistic, and was posted ahead of the meeting. It was made available in the NEO Program’s Horizons ephemeris service so that users could , for example, design their own deflection missions. The simulated asteroid and trajectory had to meet numerous very exacting requirements: becoming observable on the very first day of the conference, yet remaining very difficult to observe for the following 7 years, and far enough away from Earth that it was out of reach of radar until just before impact. It had to be undetectable in the past, and yet provide multiple perihelion opportunities for deflection in the future. It had to impact in a very specific region of the Earth, a specific number of years after discovery. When observations of the asteroid are simulated to generate an uncertainty region, that entire region must impact the Earth along an axis that cuts across specific regions of the Earth, the “risk corridor”. This is important because asteroid deflections generally move an asteroid impact point along this corridor. One scenario had a requirement that the asteroid pass through a keyhole several years before impact. The PDC15 scenario had an additional constraint that multiple simulated kinetic impactor missions altered the trajectory at a deflection point midway between discovery and impact

  10. Characterization of Transverse Isotropy in Compressed Tissue Mimicking Phantoms

    PubMed Central

    Urban, Matthew W.; Lopera, Manuela; Aristizabal, Sara; Amador, Carolina; Nenadic, Ivan; Kinnick, Randall R.; Weston, Alexander D.; Qiang, Bo; Zhang, Xiaoming; Greenleaf, James F.

    2015-01-01

    Tissues such as skeletal muscle and kidneys have well-defined structure that affects the measurements of mechanical properties. As an approach to characterize the material properties of these tissues, different groups have assumed that they are transversely isotropic (TI) and measure the shear wave velocity as it varies with angle with respect to the structural architecture of the organ. To refine measurements in these organs, it is desirable to have tissue mimicking phantoms that exhibit similar anisotropic characteristics. Some approaches involve embedding fibers into a material matrix. However, if a homogeneous solid is under compression due to a static stress, an acoustoelastic effect can manifest which makes the measured wave velocities change with the compression stress. We propose to exploit this characteristic to demonstrate that stressed tissue mimicking phantoms can be characterized as a TI material. We tested six phantoms made with different concentrations of gelatin and agar. Stress was applied by the weight of a water container centered on top of a plate on top of the phantom. A linear array transducer and a V-1 Verasonics system were used to induce and measure shear waves in the phantoms. The shear wave motion was measured using a compound plane wave imaging technique. Autocorrelation was applied to the received in-phase/quadrature data. The shear wave velocity, c, was estimated using a Radon transform method. The transducer was mounted on a rotating stage so measurements were made every 10° over a range of 0–360°, where the stress is applied along 0–180° direction. The shear moduli were estimated. A TI model was fit to the data and the fractional anisotropy was evaluated. This approach can be used to explore many configurations of transverse isotropy with the same phantom, simply by applying stress to the tissue mimicking phantom. PMID:26067038

  11. Lepra Reaction with Lucio Phenomenon Mimicking Cutaneous Vasculitis

    PubMed Central

    Misra, Durga Prasanna; Parida, Jyoti Ranjan; Chowdhury, Abhra Chandra; Pani, Krushna Chandra; Kumari, Niraj; Krishnani, Narendra

    2014-01-01

    Leprosy is a disease typically found in the tropics. Patients with leprosy can have varying presentation with constitutional symptoms, joint pains, skin nodules, and rarely a vasculitis-like picture with skin ulcers and neuropathy. We present a young lady who presented with the rare manifestation of skin infarcts mimicking cutaneous vasculitis, diagnosed on histopathology to have Lucio phenomenon on a background of lepromatous leprosy. With increasing migration and widespread use of biologic response modifiers, clinicians all over the world need to be aware of various presentations of leprosy as well as needing to keep an open mind while considering the differential diagnoses of vasculitis. PMID:25580317

  12. Lepra reaction with lucio phenomenon mimicking cutaneous vasculitis.

    PubMed

    Misra, Durga Prasanna; Parida, Jyoti Ranjan; Chowdhury, Abhra Chandra; Pani, Krushna Chandra; Kumari, Niraj; Krishnani, Narendra; Agarwal, Vikas

    2014-01-01

    Leprosy is a disease typically found in the tropics. Patients with leprosy can have varying presentation with constitutional symptoms, joint pains, skin nodules, and rarely a vasculitis-like picture with skin ulcers and neuropathy. We present a young lady who presented with the rare manifestation of skin infarcts mimicking cutaneous vasculitis, diagnosed on histopathology to have Lucio phenomenon on a background of lepromatous leprosy. With increasing migration and widespread use of biologic response modifiers, clinicians all over the world need to be aware of various presentations of leprosy as well as needing to keep an open mind while considering the differential diagnoses of vasculitis.

  13. Simple bone cyst of mandible mimicking periapical cyst

    PubMed Central

    HS, Charan Babu; Rai, Bhagawan Das; Nair, Manju A.; Astekar, Madhusudan S.

    2012-01-01

    Simple bone cysts (SBC) are pseudocysts occurring less commonly in the maxillofacial region. The uncertain and unclear etiopathogenesis led to numerous synonyms to refer this particular cyst. These cysts are devoid of an epithelial lining and are usually empty or contain blood or straw-colored fluid. In jaws initially it mimics a periapical cyst and later can lead to cortical bone expansion warranting for radical approach, which is seldom required. SBC is predominantly diagnosed in first two decades of life. Here we report a case of solitary bone cyst mimicking a periapical cyst of a mandibular molar in a 37-year-old patient. PMID:24765458

  14. Simple bone cyst of mandible mimicking periapical cyst.

    PubMed

    Hs, Charan Babu; Rai, Bhagawan Das; Nair, Manju A; Astekar, Madhusudan S

    2012-05-29

    Simple bone cysts (SBC) are pseudocysts occurring less commonly in the maxillofacial region. The uncertain and unclear etiopathogenesis led to numerous synonyms to refer this particular cyst. These cysts are devoid of an epithelial lining and are usually empty or contain blood or straw-colored fluid. In jaws initially it mimics a periapical cyst and later can lead to cortical bone expansion warranting for radical approach, which is seldom required. SBC is predominantly diagnosed in first two decades of life. Here we report a case of solitary bone cyst mimicking a periapical cyst of a mandibular molar in a 37-year-old patient.

  15. Primary oral leishmaniasis mimicking oral cancer: a case report.

    PubMed

    Celentano, A; Ruoppo, E; Mansueto, G; Mignogna, M D

    2015-04-01

    Primary mucosal leishmaniasis is a rare infectious disease, particularly in immunocompetent patients. We present a 50-year-old patient with a 6-week history of a painful lesion of the left buccal mucosa that mimicked cancer. The exophytic lesion looked invasive, and we took an incisional biopsy specimen to exclude cancer. The diagnosis of leishmaniasis was unexpected, and the patient was successfully treated with amphotericin B for five weeks. After five months the patient had a visceral recurrence. Chronic exophytic and ulcerated mucosal lesions that do not heal within 3-4 weeks should be regarded as the first signs of oral cancer, but primary oral leishmaniasis can easily mimic it.

  16. Iliacus pyomyositis mimicking septic arthritis of the hip joint.

    PubMed

    Chen W-S; Wan Y-L

    1996-01-01

    The iliacus muscle is closely associated with the psoas muscle, femoral nerve, hip joint, pelvic and intraabdominal structures; thus, its disorders may present as lower abdominal pain, hip pain, or femoral neuropathy. Iliacus pyomyositis, a primary bacterial infection of the skeletal muscle not secondary to a contiguous skin, bone, or soft-tissue infection, presenting as hip pain, femoral neuropathy, and sympathetic effusion of the hip joint in an 8-year-old boy mimicked septic arthritis of the hip joint. Computed tomography was helpful in delineating the accurate location of the lesion. Surgical drainage and appropriate antibiotic therapy led to complete resolution and full functional recovery.

  17. Steroid-responsive Hashimoto encephalopathy mimicking Creutzfeldt-Jakob disease.

    PubMed

    Santoro, Domenico; Colombo, Irene; Ghione, Isabella; Peverelli, Lorenzo; Bresolin, Nereo; Sciacco, Monica; Prelle, Alessandro

    2011-08-01

    Hashimoto's encephalopathy (HE) is a rare neurological disorder with a heterogeneous group of neurological symptoms associated with high titres of anti-thyroid antibodies. Clinical manifestations may include encephalopathic features such as seizures, behavioural and psychiatric manifestations, movement disorders and coma. The objective of this presentation is to describe a patient with this rare and controversial clinical syndrome mimicking Creutzfeldt-Jakob disease, associated with a Hashimoto euthyroid thyroiditis and with a significant response to high dose intravenous prednisone. The responsiveness of this syndrome to steroids suggests that this disorder involves immune pathogenic mechanisms, as previous reviews reported.

  18. Superficial Fibromatosis Mimicking Glomus Tumor of the Second Toe

    PubMed Central

    Jo, Hyang Jeong; Kim, Gang Deuk; Kim, Yeung Jin; Choi, Deok Hwa; Park, Jae In

    2015-01-01

    Various types of tumor can occur in the subungual space, including glomus tumors, subungual exostosis, hemangioma, epidermal cysts, and malignant tumors. While fibromatosis can occur at various sites throughout the body, it is very rarely seen in the toe. Here, we are the first to report a case of superficial fibromatosis mimicking a glomus tumor in the subungual space of the second toe. The presentation of this condition shows the possibility of encountering uncommon superficial fibromatosis in the distal phalanx of the toe, and suggests that superficial fibromatosis should be included in the differential diagnosis of a glomus tumor in the toe. PMID:26330970

  19. Subarachnoid haemorrhage mimicking transient ST-segment elevation myocardial infarction.

    PubMed

    Lai, C-H; Juan, Y-H; Chang, S-L; Lee, W-L; How, C-K; Hsu, T-F

    2015-08-01

    Patients often present to the emergency department with loss of consciousness. The differential diagnosis of such condition may be difficult because of limited clinical information. The authors present a case of subarachnoid haemorrhage (SAH) with initial electrocardiographic (ECG) finding mimicking ST-segment elevation myocardial infarction (STEMI), which was confirmed to resolve in a follow-up study. Accurate and timely diagnosis of SAH-related ST-segment elevation was important, as the therapeutic strategy for SAH is completely different from that for STEMI. If the clinicians do not have other tools for diagnosis, the follow-up ECG may help us make a most possible diagnosis.

  20. Brucellosis mimicking Henoch-Schönlein purpura.

    PubMed

    Massasso, David; Gibson, Kathryn

    2007-06-04

    A young male immigrant from Syria with a vasculitic-appearing leg rash, asymmetrical polyarthritis, microscopic haematuria, and raised inflammatory markers was provisionally diagnosed with Henoch-Schönlein purpura. Skin biopsy showed leukocytoclastic vasculitis. Low-grade fevers persisted despite non-steroidal anti-inflammatory therapy, and Brucella sp. was subsequently grown from both blood and synovial fluid aspirates. Further tests gave positive results for B. abortus, and triple antibiotic therapy produced a rapid clinical response. Cutaneous vasculitis has rarely been described in brucellosis, and this is the first report in the English medical literature of brucellosis mimicking Henoch-Schönlein purpura.

  1. Subcutaneous Phaeohyphomycosis Due to Pyrenochaeta romeroi Mimicking a Synovial Cyst

    PubMed Central

    Dinh, Aurélien; Levy, Bruno; Bouchand, Frédérique; Davido, Benjamin; Duran, Clara; Cristi, Marin; Felter, Adrien; Salomon, Jérôme; Ait Ammar, Nawel

    2016-01-01

    Opportunistic subcutaneous fungal infections are increasing nowadays due to the growing number of medical conditions causing immunosuppression, especially organ transplant. The incidence rate of subcutaneous phaeohyphomycosis is very low. Most studies found are case reports. They showed a wide variation of clinical presentations. Pyrenochaeta romeroi, a fungus from the Dematiaceae group is a saprophyte found in soil and plants and a possible causative agent of phaeohyphomycosis. We present a rare case of subcutaneous phaeohyphomycosis caused by P. romeroi mimicking a synovial cyst in a diabetic patient. PMID:27630637

  2. Multiple uterine angioleiomyomas mimicking an ovarian neoplasm: a case report.

    PubMed

    Hakverdi, S; Dolapçioğlu, K; Güngören, A; Yaldiz, M; Hakverdi, A U

    2009-01-01

    Angioleiomyoma is a rare benign neoplasm that originates from smooth muscle cells and contains thick-walled blood vessels. A 69-year-old woman had been complaining of progressive abdominal distention for the last five years. At the exploration, a tumoral mass that could not be differentiated as to whether it had its origin from the uterus or ovary was specified. The patient underwent total hysterectomy and bilateral salpingo-oophorectomy (TAH+BSO). On pathologic examination of the specimen, the tumor was diagnosed as an angioleiomyoma. Here, we present a case of giant-multiple uterine angioleiomyomas mimicking an ovarian neoplasm.

  3. Aggressive Indeterminate Dendritic Cell Tumor Mimicking Scalp Angiosarcoma.

    PubMed

    Li, Yun; Wang, Ting-Ting; Zhang, Zi-Hui; Wang, Lin

    2017-10-01

    Indeterminate dendritic cell tumor (IDCT) is a proliferation of CD1a+, S100+ and langerin- histiocytes with a generally benign course. Here, we describe a case of a 90-year-old male who developed skin lesions on his scalp mimicking angiosarcoma and lymphadenopathy. He died six months after the onset of skin lesions despite of months' radiotherapy. Pathological examination ruled out scalp angiosarcoma and showed a high Ki-67 index. The appearance of skin lesions and lymphadenopathy led to challenges in diagnosis and the development of a treatment plan.

  4. Intimal Sarcoma of the Descending Aorta Mimicking Aortitis

    PubMed Central

    Pucci, Angela; De Martino, Andrea; Levantino, Maurizio; Berchiolli, Raffaella; Basolo, Fulvio; Bortolotti, Uberto

    2016-01-01

    We describe a 74-year-old male patient with an intimal sarcoma of the descending aorta mimicking aortitis. The patient presented with lower back pain, fever, and increased C-reactive protein, erythrocyte sedimentation rate, and immunoglobulin G4 (IgG4) serum levels, together with Staphylococcus epidermidis-positive blood cultures. These findings, together with evidence of a 49-mm pseudoaneurysm of the descending thoracic aorta, caused us to suspect aortitis. However, postoperative histology and immunohistochemistry demonstrated the presence of an intimal aortic sarcoma. At the 8-month follow-up, local recurrence of the neoplasm and lung metastases were noted. PMID:28097198

  5. Klebsiella pneumoniae pharyngitis mimicking malignancy: a diagnostic dilemma.

    PubMed

    Yeh, C-F; Li, W-Y; Hsu, Y-B

    2014-12-01

    Acute pharyngitis is a common disease. However, acute pharyngitis caused by Klebsiella pneumoniae with a gross appearance mimicking hypopharyngeal malignancy has never previously been reported. We report the case of a 57-year-old man with a right hypopharyngeal tumor which was disclosed by fiberoptic laryngoscopy and computed tomography scan. However, both the frozen and final pathologies showed no evidence of malignant cells, and a bacterial culture revealed the growth of K. pneumoniae. The hypopharyngeal lesion completely regressed after 2 weeks of antibiotic treatment. Clinicians should perform biopsy along with tissue culture for tumor-like lesions because infectious agents can lead to lesions with malignancy-like appearance.

  6. A case of generalized ostraceous psoriasis mimicking dermatitis neglecta.

    PubMed

    Nascimento, Bianca Angelina Macêdo do; Carvalho, Alessandra Haber; Dias, Carolina Moraes; Lage, Thaiane Lima; Carneiro, Clívia Maria Oliveira; Bittencourt, Maraya de Jesus Semblano

    2015-01-01

    Lithium has been implicated in the exacerbation of pre-existing psoriasis, in the induction of psoriasis on previously uninvolved skin of psoriasis patients, and in the triggering of psoriasis for the first time in patients without a personal or family history. Lithium-induced psoriasis (and its resistance to treatment) is one of the major reasons for noncompliance in patients treated with lithium. We describe a male patient who developed generalized ostraceous psoriasis whose clinical appearance mimicked dermatitis neglecta, 10 months after starting therapy with lithium.

  7. Hepatitis A infection mimicking adult onset Still's disease.

    PubMed

    Sridharan, S; Mossad, S; Hoffman, G

    2000-07-01

    Fever, rash, and arthritis may be components of the prodrome of viral hepatitis. In the absence of jaundice and abnormal liver function tests, this form of polyarthritis is easily confused with primary autoimmune diseases. Whereas the association of systemic illness with musculoskeletal symptoms and numerous viral infections is well known, such an association with hepatitis A has only been rarely reported. We describe a case of hepatitis A infection mimicking adult onset Still's disease, and review the pathogenesis and differential diagnosis of Still's disease and the extraarticular manifestations of hepatitis.

  8. Subacute combined degeneration mimicking traumatic spinal cord injury.

    PubMed

    Paul, Ian; Reichard, R Ross

    2009-03-01

    Subacute combined degeneration (SCD) of the spinal cord is the most common neurologic manifestation of vitamin B12 (cobalamin) deficiency and is usually secondary to autoimmune gastritis, but may also be seen in malnutrition syndromes such as chronic alcoholism, strict vegetarianism, gastrectomy, and also in nitrous oxide abuse. Although traumatic spinal cord injury is routinely encountered in the medical examiner's office, medical causes of spinal cord abnormalities such as SCD should be considered in the appropriate clinical setting. We report a case of alcohol-associated SCD mimicking traumatic spinal cord injury.

  9. Endometriosis after surgical menopause mimicking pelvic malignancy: surgeons' predicament.

    PubMed

    Bhat, Rani A; Teo, Melissa; Bhat, Akhil Krishnanand

    2014-05-01

    Prevalence of persistent endometriosis in women after menopause without any hormonal replacement therapy is very rare. This is a case of a woman with previous history of total hysterectomy and bilateral salpingo-oophorectomy for endometriosis who presented with hemoperitoneum, vaginal bleeding, pelvic mass, and pulmonary thromboembolism mimicking as rectovaginal septum carcinoma. This is the first case report with a unique mode of presentation wherein the patient presented with hemoperitoneum requiring emergency embolization of the vessel to stabilize the patient. She underwent en bloc resection of the tumor with high anterior resection of the rectum. Histopathology confirmed endometriosis.

  10. Endometriosis After Surgical Menopause Mimicking Pelvic Malignancy: Surgeons’ Predicament

    PubMed Central

    Bhat, Rani A.; Teo, Melissa; Bhat, Akhil Krishnanand

    2014-01-01

    Prevalence of persistent endometriosis in women after menopause without any hormonal replacement therapy is very rare. This is a case of a woman with previous history of total hysterectomy and bilateral salpingo-oophorectomy for endometriosis who presented with hemoperitoneum, vaginal bleeding, pelvic mass, and pulmonary thromboembolism mimicking as rectovaginal septum carcinoma. This is the first case report with a unique mode of presentation wherein the patient presented with hemoperitoneum requiring emergency embolization of the vessel to stabilize the patient. She underwent en bloc resection of the tumor with high anterior resection of the rectum. Histopathology confirmed endometriosis. PMID:24936277

  11. A case of generalized ostraceous psoriasis mimicking dermatitis neglecta*

    PubMed Central

    do Nascimento, Bianca Angelina Macêdo; Carvalho, Alessandra Haber; Dias, Carolina Moraes; Lage, Thaiane Lima; Carneiro, Clívia Maria Oliveira; Bittencourt, Maraya de Jesus Semblano

    2015-01-01

    Lithium has been implicated in the exacerbation of pre-existing psoriasis, in the induction of psoriasis on previously uninvolved skin of psoriasis patients, and in the triggering of psoriasis for the first time in patients without a personal or family history. Lithium-induced psoriasis (and its resistance to treatment) is one of the major reasons for noncompliance in patients treated with lithium. We describe a male patient who developed generalized ostraceous psoriasis whose clinical appearance mimicked dermatitis neglecta, 10 months after starting therapy with lithium. PMID:26312715

  12. Anisotropic microstructured poly(vinyl alcohol) tissue-mimicking phantoms.

    PubMed

    Dawson, Andrew; Harris, Paul; Gouws, Gideon

    2010-07-01

    Novel microstructured PVA phantoms mimicking fibrous tissues have been developed using a simple freeze-casting process. Scanning electron micrographs reveal highly anisotropic microstructure with dimensions of the order of 5 to 100 microm. Characterization of an example phantom revealed acoustic properties consistent with those found in fibrous tissues. At 20 MHz, the velocity measured parallel to the microstructure orientation of 1555 ms(-1) was significantly greater than that perpendicular to the microstructure of 1537 ms(-1). The attenuation coefficient was measured to be 5 dBxmm(-1) and proportional to the 1.6 power of frequency, which is in good agreement with that for normal human myocardium.

  13. Giant submandibular gland duct sialolith mimicking an impacted canine tooth

    PubMed Central

    Bhullar, Ramandeep Singh; Dhawan, Amit; Bhullar, Kanwalpreet; Malhotra, Sonia

    2015-01-01

    Sialolithiasis is the most common disease affecting the salivary glands and accounts for 80% of salivary gland disorders. Chronic sialolithiasis promotes stone formation. Size of the salivary stones may range from 0.1 mm to 30 mm or be even bigger. Those salivary stones, the size of which exceeds 15 mm in any one dimension or 1 g in weight are classified as giant sialoliths. Giant sialoliths of the submandibular gland duct are rarely reported. Here, we report a case of a giant sialolith of the submandibular gland duct mimicking an impacted mandibular canine tooth on routine radiographic examination and its surgical management through an intraoral approach. PMID:26668461

  14. Tissue-Mimicking Materials Using Segmented Polyurethane Gel and Their Acoustic Properties

    NASA Astrophysics Data System (ADS)

    Yoshida, Tomoji; Tanaka, Kouhei; Kondo, Toshio; Yasukawa, Kazuhiro; Miyamoto, Nobuaki; Taniguchi, Masahiko; Shikinami, Yasuo

    2012-07-01

    Accurate testing of an instrument by phantoms requires a tissue-mimicking material that has the acoustic velocity and density defined in the International Electrotechnical Commission (IEC) standard, and furthermore the tissue-mimicking material must be stable over time. To achieve the tissue-mimicking materials with the desired acoustic velocity and density defined in the IEC standard, new materials have been developed. The form of tissue-mimicking materials reported comprised polystyrene and poly(methyl methacrylate) (PMMA) particles dispersed in segmented polyurethane gel. They were stable over a period of 40 days and the changes in weight and acoustic velocity did not exceed 0.5%.

  15. Europa Explorer Operational Scenarios Development

    NASA Technical Reports Server (NTRS)

    Lock, Robert E.; Pappalardo, Robert T.; Clark, Karla B.

    2008-01-01

    In 2007, NASA conducted four advanced mission concept studies for outer planets targets: Europa, Ganymede, Titan and Enceladus. The studies were conducted in close cooperation with the planetary science community. Of the four, the Europa Explorer Concept Study focused on refining mission options, science trades and implementation details for a potential flagship mission to Europa in the 2015 timeframe. A science definition team (SDT) was appointed by NASA to guide the study. A JPL-led engineering team worked closely with the science team to address 3 major focus areas: 1) credible cost estimates, 2) rationale and logical discussion of radiation risk and mitigation approaches, and 3) better definition and exploration of science operational scenario trade space. This paper will address the methods and results of the collaborative process used to develop Europa Explorer operations scenarios. Working in concert with the SDT, and in parallel with the SDT's development of a science value matrix, key mission capabilities and constraints were challenged by the science and engineering members of the team. Science goals were advanced and options were considered for observation scenarios. Data collection and return strategies were tested via simulation, and mission performance was estimated and balanced with flight and ground system resources and science priorities. The key to this successful collaboration was a concurrent development environment in which all stakeholders could rapidly assess the feasibility of strategies for their success in the full system context. Issues of science and instrument compatibility, system constraints, and mission opportunities were treated analytically and objectively leading to complementary strategies for observation and data return. Current plans are that this approach, as part of the system engineering process, will continue as the Europa Explorer Concept Study moves toward becoming a development project.

  16. Spent fuel receipt scenarios study

    SciTech Connect

    Ballou, L.B.; Montan, D.N.; Revelli, M.A.

    1990-09-01

    This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs.

  17. Europa Explorer Operational Scenarios Development

    NASA Technical Reports Server (NTRS)

    Lock, Robert E.; Pappalardo, Robert T.; Clark, Karla B.

    2008-01-01

    In 2007, NASA conducted four advanced mission concept studies for outer planets targets: Europa, Ganymede, Titan and Enceladus. The studies were conducted in close cooperation with the planetary science community. Of the four, the Europa Explorer Concept Study focused on refining mission options, science trades and implementation details for a potential flagship mission to Europa in the 2015 timeframe. A science definition team (SDT) was appointed by NASA to guide the study. A JPL-led engineering team worked closely with the science team to address 3 major focus areas: 1) credible cost estimates, 2) rationale and logical discussion of radiation risk and mitigation approaches, and 3) better definition and exploration of science operational scenario trade space. This paper will address the methods and results of the collaborative process used to develop Europa Explorer operations scenarios. Working in concert with the SDT, and in parallel with the SDT's development of a science value matrix, key mission capabilities and constraints were challenged by the science and engineering members of the team. Science goals were advanced and options were considered for observation scenarios. Data collection and return strategies were tested via simulation, and mission performance was estimated and balanced with flight and ground system resources and science priorities. The key to this successful collaboration was a concurrent development environment in which all stakeholders could rapidly assess the feasibility of strategies for their success in the full system context. Issues of science and instrument compatibility, system constraints, and mission opportunities were treated analytically and objectively leading to complementary strategies for observation and data return. Current plans are that this approach, as part of the system engineering process, will continue as the Europa Explorer Concept Study moves toward becoming a development project.

  18. Threatened species and the potential loss of phylogenetic diversity: conservation scenarios based on estimated extinction probabilities and phylogenetic risk analysis.

    PubMed

    Faith, Daniel P

    2008-12-01

    New species conservation strategies, including the EDGE of Existence (EDGE) program, have expanded threatened species assessments by integrating information about species' phylogenetic distinctiveness. Distinctiveness has been measured through simple scores that assign shared credit among species for evolutionary heritage represented by the deeper phylogenetic branches. A species with a high score combined with a high extinction probability receives high priority for conservation efforts. Simple hypothetical scenarios for phylogenetic trees and extinction probabilities demonstrate how such scoring approaches can provide inefficient priorities for conservation. An existing probabilistic framework derived from the phylogenetic diversity measure (PD) properly captures the idea of shared responsibility for the persistence of evolutionary history. It avoids static scores, takes into account the status of close relatives through their extinction probabilities, and allows for the necessary updating of priorities in light of changes in species threat status. A hypothetical phylogenetic tree illustrates how changes in extinction probabilities of one or more species translate into changes in expected PD. The probabilistic PD framework provided a range of strategies that moved beyond expected PD to better consider worst-case PD losses. In another example, risk aversion gave higher priority to a conservation program that provided a smaller, but less risky, gain in expected PD. The EDGE program could continue to promote a list of top species conservation priorities through application of probabilistic PD and simple estimates of current extinction probability. The list might be a dynamic one, with all the priority scores updated as extinction probabilities change. Results of recent studies suggest that estimation of extinction probabilities derived from the red list criteria linked to changes in species range sizes may provide estimated probabilities for many different species

  19. Characterization of various tissue mimicking materials for medical ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Thouvenot, Audrey; Poepping, Tamie; Peters, Terry M.; Chen, Elvis C. S.

    2016-04-01

    Tissue mimicking materials are physical constructs exhibiting certain desired properties, which are used in machine calibration, medical imaging research, surgical planning, training, and simulation. For medical ultrasound, those specific properties include acoustic propagation speed and attenuation coefficient over the diagnostic frequency range. We investigated the acoustic characteristics of polyvinyl chloride (PVC) plastisol, polydimethylsiloxane (PDMS), and isopropanol using a time-of-light technique, where a pulse was passed through a sample of known thickness contained in a water bath. The propagation speed in PVC is approximately 1400ms-1 depending on the exact chemical composition, with the attenuation coefficient ranging from 0:35 dB cm-1 at 1MHz to 10:57 dB cm-1 at 9 MHz. The propagation speed in PDMS is in the range of 1100ms-1, with an attenuation coefficient of 1:28 dB cm-1 at 1MHz to 21:22 dB cm-1 at 9 MHz. At room temperature (22 °C), a mixture of water-isopropanol (7:25% isopropanol by volume) exhibits a propagation speed of 1540ms-1, making it an excellent and inexpensive tissue-mimicking liquid for medical ultrasound imaging.

  20. Circumscribed choroidal haemangioma mimicking chronic central serous chorioretinopathy.

    PubMed

    Rahman, W; Horgan, N; Hungerford, J

    2013-03-01

    We describe a rare case of bilateral circumscribed choroidal haemangioma in an otherwise healthy male, which mimicked chronic central serous chorioretinopathy (CSCR). A 52-year-old Asian man presented with a one-year history of visual decline in his left eye. The vision in the right eye had been reduced for 15 years. Visual acuity was 6/60 in the right eye and 6/18 in the left eye. Fundus examination of the right eye revealed an area of discoloration with overlying retinal pigment epithelial changes in the macula and evidence of prior surrounding argon laser photocoagulation. The left macula showed a raised choroidal lesion with overlying retinal pigment epithelial changes and associated subretinal fluid. This appearance illustrates how chronic retinal pigment epithelial alterations associated with longstanding subretinal fluid exudation from circumscribed choroidal haemangiomas may mimick the appearance of chronic central serous chorioretinopathy. B-scan ultrasonography, fluorescein angiography, indocyanine green angiography and optical coherence tomography helped to establish the diagnosis. The active lesion in the left eye was treated with verteporfin photodynamic therapy with improvement in vision.

  1. Tissue-mimicking phantoms for photoacoustic and ultrasonic imaging

    PubMed Central

    Cook, Jason R.; Bouchard, Richard R.; Emelianov, Stanislav Y.

    2011-01-01

    In both photoacoustic (PA) and ultrasonic (US) imaging, overall image quality is influenced by the optical and acoustical properties of the medium. Consequently, with the increased use of combined PA and US (PAUS) imaging in preclinical and clinical applications, the ability to provide phantoms that are capable of mimicking desired properties of soft tissues is critical. To this end, gelatin-based phantoms were constructed with various additives to provide realistic acoustic and optical properties. Forty-micron, spherical silica particles were used to induce acoustic scattering, Intralipid® 20% IV fat emulsion was employed to enhance optical scattering and ultrasonic attenuation, while India Ink, Direct Red 81, and Evans blue dyes were utilized to achieve optical absorption typical of soft tissues. The following parameters were then measured in each phantom formulation: speed of sound, acoustic attenuation (from 6 to 22 MHz), acoustic backscatter coefficient (from 6 to 22 MHz), optical absorption (from 400 nm to 1300 nm), and optical scattering (from 400 nm to 1300 nm). Results from these measurements were then compared to similar measurements, which are offered by the literature, for various soft tissue types. Based on these comparisons, it was shown that a reasonably accurate tissue-mimicking phantom could be constructed using a gelatin base with the aforementioned additives. Thus, it is possible to construct a phantom that mimics specific tissue acoustical and/or optical properties for the purpose of PAUS imaging studies. PMID:22076278

  2. Spontaneous motor entrainment to music in multiple vocal mimicking species.

    PubMed

    Schachner, Adena; Brady, Timothy F; Pepperberg, Irene M; Hauser, Marc D

    2009-05-26

    The human capacity for music consists of certain core phenomena, including the tendency to entrain, or align movement, to an external auditory pulse [1-3]. This ability, fundamental both for music production and for coordinated dance, has been repeatedly highlighted as uniquely human [4-11]. However, it has recently been hypothesized that entrainment evolved as a by-product of vocal mimicry, generating the strong prediction that only vocal mimicking animals may be able to entrain [12, 13]. Here we provide comparative data demonstrating the existence of two proficient vocal mimicking nonhuman animals (parrots) that entrain to music, spontaneously producing synchronized movements resembling human dance. We also provide an extensive comparative data set from a global video database systematically analyzed for evidence of entrainment in hundreds of species both capable and incapable of vocal mimicry. Despite the higher representation of vocal nonmimics in the database and comparable exposure of mimics and nonmimics to humans and music, only vocal mimics showed evidence of entrainment. We conclude that entrainment is not unique to humans and that the distribution of entrainment across species supports the hypothesis that entrainment evolved as a by-product of selection for vocal mimicry.

  3. Scenarios for coastal vulnerability assessment

    USGS Publications Warehouse

    Nicholls, Robert J.; Woodroffe, Colin D.; Burkett, Virginia; Hay, John; Wong, Poh Poh; Nurse, Leonard; Wolanski, Eric; McLusky, Donald S.

    2011-01-01

    Coastal vulnerability assessments tend to focus mainly on climate change and especially on sea-level rise. Assessment of the influence of nonclimatic environmental change or socioeconomic change is less well developed and these drivers are often completely ignored. Given that the most profound coastal changes of the twentieth century due to nonclimate drivers are likely to continue through the twenty-first century, this is a major omission. It may result in not only overstating the importance of climate change but also overlooking significant interactions of climate change and other drivers. To support the development of policies relating to climate change and coastal management, integrated assessments of climatic change in coastal areas are required, including the effects of all the relevant drivers. This chapter explores the development of scenarios (or "plausible futures") of relevant climate and nonclimate drivers that can be used for coastal analysis, with an emphasis on the nonclimate drivers. It shows the importance of analyzing the impacts of climate change and sea-level rise in a broader context of coastal change and all its drivers. This will improve the analysis of impacts, key vulnerabilities, and adaptation needs and, hence, inform climate and coastal policy. Stakeholder engagement is important in the development of scenarios, and the underlying assumptions need to be explicit, transparent, and open to scientific debate concerning their uncertainties/realism and likelihood.

  4. Scenario Development for the Southwestern United States

    NASA Astrophysics Data System (ADS)

    Mahmoud, M.; Gupta, H.; Stewart, S.; Liu, Y.; Hartmann, H.; Wagener, T.

    2006-12-01

    The primary goal of employing a scenario development approach for the U.S. southwest is to inform regional policy by examining future possibilities related to regional vegetation change, water-leasing, and riparian restoration. This approach is necessary due to a lack of existing explicit water resources application of scenarios to the entire southwest region. A formal approach for scenario development is adopted and applied towards water resources issues within the arid and semi-arid regions of the U.S. southwest following five progressive and reiterative phases: scenario definition, scenario construction, scenario analysis, scenario assessment, and risk management. In the scenario definition phase, the inputs of scientists, modelers, and stakeholders were collected in order to define and construct relevant scenarios to the southwest and its water sustainability needs. From stakeholder-driven scenario workshops and breakout sessions, the three main axes of principal change were identified to be climate change, population development patterns, and quality of information monitoring technology. Based on the extreme and varying conditions of these three main axes, eight scenario narratives were drafted to describe the state of each scenario's respective future and the events which led to it. Events and situations are described within each scenario narrative with respect to key variables; variables that are both important to regional water resources (as distinguished by scientists and modelers), and are good tracking and monitoring indicators of change. The current phase consists of scenario construction, where the drafted scenarios are re-presented to regional scientists and modelers to verify that proper key variables are included (or excluded) from the eight narratives. The next step is to construct the data sets necessary to implement the eight scenarios on the respective computational models of modelers investigating vegetation change, water-leasing, and riparian

  5. Development and Change through Scenario Planning

    ERIC Educational Resources Information Center

    Chermack, Thomas J.; Walton, John S.

    2004-01-01

    This paper examines the role of scenario planning as a development and change intervention. To do so, this article provides an overview of scenario planning and an overview of development and change in organizations. The article then builds on the philosophical orientations of development and change through scenario planning introducing the…

  6. Acute chylous ascites mimicking acute appendicitis in a patient with pancreatitis.

    PubMed

    Smith, Emily K; Ek, Edmund; Croagh, Daniel; Spain, Lavinia A; Farrell, Stephen

    2009-10-14

    We report a case of acute chylous peritonitis mimicking acute appendicitis in a man with acute on chronic pancreatitis. Pancreatitis, both acute and chronic, causing the development of acute chylous ascites and peritonitis has rarely been reported in the English literature. This is the fourth published case of acute chylous ascites mimicking acute appendicitis in the literature.

  7. Tsunami hazard potential for the equatorial southwestern Pacific atolls of Tokelau from scenario-based simulations

    NASA Astrophysics Data System (ADS)

    Orpin, A. R.; Rickard, G. J.; Gerring, P. K.; Lamarche, G.

    2015-07-01

    Devastating tsunami over the last decade have significantly heightened awareness of the potential consequences and vulnerability to tsunami for low-lying Pacific islands and coastal regions. Our tsunami risk assessment for the atolls of the Tokelau Islands was based on a tsunami source-propagation-inundation model using Gerris Flow Solver, adapted from the companion study by Lamarche et al. (2015) for the islands of Wallis and Futuna. We assess whether there is potential for tsunami flooding on any of the village islets from a series of fourteen earthquake-source experiments that apply a combination of well-established fault parameters to represent plausible "high-risk scenarios" for each of the tsunamigenic sources. Earthquake source location and moment magnitude were related to tsunami wave heights and tsunami flood depths simulated for each of the three atolls of Tokelau. This approach was adopted to yield indicative and instructive results for a community advisory, rather than being fully deterministic. Results from our modelling show that wave fields are channelled by the bathymetry of the Pacific basin in such a way that the swathes of the highest waves sweep immediately northeast of the Tokelau Islands. From our series of limited simulations a great earthquake from the Kuril Trench poses the most significant inundation threat to Tokelau, with maximum modelled-wave heights in excess of 1 m, which may last a few hours and include several wave trains. Other sources can impact specific sectors of the atolls, particularly from regional sources to the south, and northern and eastern distant sources that generate trans-Pacific tsunami. In many cases impacts are dependent on the wave orientation and direct exposure to the oncoming tsunami. This study shows that dry areas remain around the villages in nearly all our "worst-case" tsunami simulations of the Tokelau Islands. Consistent with the oral history of little or no perceived tsunami threat, simulations from the

  8. The ShakeOut Scenario

    USGS Publications Warehouse

    Jones, Lucile M.; Bernknopf, Richard; Cox, Dale; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Perry, Suzanne; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne

    2008-01-01

    This is the initial publication of the results of a cooperative project to examine the implications of a major earthquake in southern California. The study comprised eight counties: Imperial, Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura. Its results will be used as the basis of an emergency response and preparedness exercise, the Great Southern California ShakeOut, and for this purpose we defined our earthquake as occurring at 10:00 a.m. on November 13, 2008. As members of the southern California community use the ShakeOut Scenario to plan and execute the exercise, we anticipate discussion and feedback. This community input will be used to refine our assessment and will lead to a formal publication in early 2009. Our goal in the ShakeOut Scenario is to identify the physical, social and economic consequences of a major earthquake in southern California and in so doing, enable the users of our results to identify what they can change now?before the earthquake?to avoid catastrophic impact after the inevitable earthquake occurs. To do so, we had to determine the physical damages (casualties and losses) caused by the earthquake and the impact of those damages on the region?s social and economic systems. To do this, we needed to know about the earthquake ground shaking and fault rupture. So we first constructed an earthquake, taking all available earthquake research information, from trenching and exposed evidence of prehistoric earthquakes, to analysis of instrumental recordings of large earthquakes and the latest theory in earthquake source physics. We modeled a magnitude (M) 7.8 earthquake on the southern San Andreas Fault, a plausible event on the fault most likely to produce a major earthquake. This information was then fed forward into the rest of the ShakeOut Scenario. The damage impacts of the scenario earthquake were estimated using both HAZUS-MH and expert opinion through 13 special studies and 6 expert panels, and fall into four

  9. Superclustering in the explosion scenario

    NASA Technical Reports Server (NTRS)

    Weinberg, David H.; Ostriker, Jeremiah P.; Dekel, Avishai

    1989-01-01

    A simple toy model is used to study the spatial distribution of rich clusters in a generic type of explosion scenario. The model, parameterized by the distribution of shell radii and the filling factor, places spherical shells at random and identifies each 'knot' as a cluster. The resulting cluster correlation function is close to a power law extending to the diameter of the largest spheres. Richer clusters form at the intersections of bigger shells and so have stronger correlations. Typical shell radii and filling factors are required to produce the observed number density of clusters. Models with a power-law radius distribution also reproduce the richness distribution of clusters in the Abell catalog. Supercluster multiplicity functions, void probabilities, number counts, topology statistics, and velocity correlations confirm the presence of strong superclustering and quantify the non-Gaussian nature of the model.

  10. Superclustering in the explosion scenario

    NASA Technical Reports Server (NTRS)

    Weinberg, David H.; Ostriker, Jeremiah P.; Dekel, Avishai

    1989-01-01

    A simple toy model is used to study the spatial distribution of rich clusters in a generic type of explosion scenario. The model, parameterized by the distribution of shell radii and the filling factor, places spherical shells at random and identifies each 'knot' as a cluster. The resulting cluster correlation function is close to a power law extending to the diameter of the largest spheres. Richer clusters form at the intersections of bigger shells and so have stronger correlations. Typical shell radii and filling factors are required to produce the observed number density of clusters. Models with a power-law radius distribution also reproduce the richness distribution of clusters in the Abell catalog. Supercluster multiplicity functions, void probabilities, number counts, topology statistics, and velocity correlations confirm the presence of strong superclustering and quantify the non-Gaussian nature of the model.

  11. Radiation Detection Computational Benchmark Scenarios

    SciTech Connect

    Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

    2013-09-24

    Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for

  12. Hydropower and water supply: competing water uses under a future drier climate modeling scenarios for the Tagus River basin, Portugal

    NASA Astrophysics Data System (ADS)

    Alexandre Diogo, Paulo; Nunes, João Pedro; Carmona Rodrigues, António; João Cruz, Maria; Grosso, Nuno

    2014-05-01

    drought periods, probably more acute by the year 2100 and in scenario A2. As a result, a decrease in inflows to the Castelo de Bode reservoir between 20 to 34% is expected, with emphasis in autumn. While for the near-term scenarios this is mostly due to a decrease in median annual inflow; for the long-term scenarios this is accompanied by lower inter-annual variability and a decrease of magnitude of wet year inflows. Associated with increased precipitation erosion potential, watershed sediment transport will probably tend to increase, enhancing phosphorous transport into surface water and thus contributing to potential eutrophication problems. However, modeling results do not indicate compromising water quality degradation. Decreased reservoir inflows should nevertheless be sufficient to sustain water supply, considering an average annual consumption of 160 hm3 y-1 and the legal prioritization of water supply over hydropower production, as worst case average annual inflows scenarios are estimated between 1 000 and 1 500 hm3 y-1. On the other hand, considering that hydropower comprises downstream releases averaging 1 400 hm3 y-1, restrictions to energy production will probably be required to compensate lower inflow periods and guaranty necessary water supply storage volumes. The presented modeling framework provided an adequate tool for assessing climate change impacts on water resources, demonstrating that climate scenarios are not likely to threaten Lisbon's water supply system but emphasizing the need for adequate reservoir management strategies contemplating the risk of competitive water uses in the Castelo de Bode reservoir.

  13. Atypical Ormond's disease associated with bile duct stricture mimicking cholangiocarcinoma.

    PubMed

    Quante, Michael; Appenrodt, Beate; Randerath, Simone; Wolff, Martin; Fischer, Hans-Peter; Sauerbruch, Tilman

    2009-01-01

    A 55-year-old woman with suspected hilar cholangiocarcinoma presented with jaundice and dilated intrahepatic bile ducts owing to high-grade hepatic duct confluence stenosis. The suspected tumour and the entire extrahepatic bile duct system were resected and Roux-en-Y hepaticojejunostomy was performed. Histological investigations showed perihepatic fibrosis but no signs of malignancy. One year later the patient developed bilateral hydronephrosis caused by ureteral obstruction. Since the patient had a gynaecological history of widespread inflammation, she was referred for transabdominal operative ureterolysis combined with hysterectomy and adnexectomy. Histological investigations as well as fluorodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) findings were compatible with retroperitoneal fibrosis (Ormond's disease). Treatment with tamoxifen was initiated. To the best of our knowledge, only a few cases of intraperitoneal fibroses mimicking cholangiocarcinoma followed by the typical symptoms of retroperitoneal Ormond's disease have been reported.

  14. Intussusception of Rectosigmoid Colon Cancer Mimicking a Pedunculated Tumor

    PubMed Central

    Saigusa, Susumu; Ohi, Masaki; Imaoka, Hiroki; Shimura, Tadanobu; Inoue, Yasuhiro; Kusunoki, Masato

    2014-01-01

    Intussusception in adults is a rare phenomenon involving the colon in approximately 20% of cases. A 65-year-old man was hospitalized with anorexia, anemia, dehydration, and melena. Digital rectal examination revealed a palpable mass approximately 5 cm from the anal verge. The mass moved between the rectosigmoid colon and the rectum below the peritoneal reflection during radiographic examinations and during sigmoidoscopy. We strongly suspected a rectosigmoid pedunculated tumor and performed a low anterior resection. Intraoperatively we observed intussusception of the rectosigmoid colon with easy manual reduction. The tumor was palpable in the rectosigmoid colon. The postoperative course was uneventful. This case illustrates intussusception of a rectosigmoid type 1 colon adenocarcinoma mimicking a pedunculated tumor. PMID:24963434

  15. Sarcoidosis mimicking a venous ulcer: a case report.

    PubMed

    Joshi, Smita S; Romanelli, Paolo; Kirsner, Robert S

    2009-11-01

    Sarcoidosis--a chronic, multisystem disease of unknown etiology characterized by noncaseating granulomas--may cause ulcerative lesions, particularly in African American women. A case of ulcerative sarcoidosis mimicking a venous ulcer is presented. The patient is a 44-year-old African American hypertensive, obese woman with a nonhealing medially based lower leg ulcer of 3 years' duration clinically consistent with a venous ulcer. The ulcer did not heal with compression therapy and pentoxifylline. Subsequent biopsies showed granulomatous inflammation consistent with sarcoidosis. When intralesional triamcinolone was added to compression therapy, the ulcer resolved after 3 months. Given its propensity toward formation on the lower extremities and ulcerative and atrophic appearance, ulcerative sarcoidosis should be considered in the differential diagnosis of a venous ulcer refractory to standard therapy, especially in African American women.

  16. Optofluidic phantom mimicking optical properties of porcine livers

    PubMed Central

    Long, Ruiqi; King, Travis; Akl, Tony; Ericson, M. Nance; Wilson, Mark; Coté, Gerard L.; McShane, Michael J.

    2011-01-01

    One strategy for assessing efficacy of a liver transplant is to monitor perfusion and oxygenation after transplantation. An implantable optical sensor is being developed to overcome inadequacies of current monitoring approaches. To facilitate sensor design while minimizing animal use, a polydimethylsiloxane (PDMS)-based liver phantom was developed to mimic the optical properties of porcine liver in the 630-1000 nm wavelength range and the anatomical geometry of liver parenchyma. Using soft lithography to construct microfluidic channels in pigmented elastomer enabled the 2D approximation of hexagonal liver lobules with 15mm sinusoidal channels, which will allow perfusion with blood-mimicking fluids to facilitate the development of the liver perfusion and oxygenation monitoring system. PMID:21750766

  17. An Adolescent Patient with Scabies Mimicking Gottron Papules.

    PubMed

    Yoshinaga, Eiji; Oiso, Naoki; Kawara, Shigeru; Kawada, Akira

    2009-01-13

    Atypical features of scabies occur in infants and children and patients with prolonged use of corticosteroids or immunosuppression. We report a non-immunosuppressed 15-year-old female case of scabies showing scaly reddish papules over the proximal interphalangeal joints mimicking Gottron papules in classic dermatomyositis. Periungal erythema was also seen. Four months' topical corticosteroids from previous clinics had been used. Dermoscopic findings were consistent with typical pictures of scabies. Scraping of hand crusts demonstrated scabies mites and ova. Skin lesions of the patient were cured with oral ivermectin and topical 10% crotamiton. This case suggests that a lesion resembling Gottron papules may be added to the panel of unusual presentations of scabies.

  18. An Adolescent Patient with Scabies Mimicking Gottron Papules

    PubMed Central

    Yoshinaga, Eiji; Oiso, Naoki; Kawara, Shigeru; Kawada, Akira

    2010-01-01

    Atypical features of scabies occur in infants and children and patients with prolonged use of corticosteroids or immunosuppression. We report a non-immunosuppressed 15-year-old female case of scabies showing scaly reddish papules over the proximal interphalangeal joints mimicking Gottron papules in classic dermatomyositis. Periungal erythema was also seen. Four months’ topical corticosteroids from previous clinics had been used. Dermoscopic findings were consistent with typical pictures of scabies. Scraping of hand crusts demonstrated scabies mites and ova. Skin lesions of the patient were cured with oral ivermectin and topical 10% crotamiton. This case suggests that a lesion resembling Gottron papules may be added to the panel of unusual presentations of scabies. PMID:21173918

  19. Dense Deposit Disease Mimicking a Renal Small Vessel Vasculitis

    PubMed Central

    Singh, Lavleen; Bhardwaj, Swati; Sinha, Aditi; Bagga, Arvind; Dinda, Amit

    2016-01-01

    Dense deposit disease is caused by fluid-phase dysregulation of the alternative complement pathway and frequently deviates from the classic membranoproliferative pattern of injury on light microscopy. Other patterns of injury described for dense deposit disease include mesangioproliferative, acute proliferative/exudative, and crescentic GN. Regardless of the histologic pattern, C3 glomerulopathy, which includes dense deposit disease and C3 GN, is defined by immunofluorescence intensity of C3c two or more orders of magnitude greater than any other immune reactant (on a 0–3 scale). Ultrastructural appearances distinguish dense deposit disease and C3 GN. Focal and segmental necrotizing glomerular lesions with crescents, mimicking a small vessel vasculitis such as ANCA-associated GN, are a very rare manifestation of dense deposit disease. We describe our experience with this unusual histologic presentation and distinct clinical course of dense deposit disease, discuss the pitfalls in diagnosis, examine differential diagnoses, and review the relevant literature. PMID:26361799

  20. Subungual onycholemmal cyst of the toenail mimicking subungual melanoma.

    PubMed

    Busquets, Joanna; Banala, Mounica; Campanelli, Carmen; Sahu, Joya; Lee, Jason B

    2016-08-01

    This report highlights a rare case of a woman with horizontal ridging and tenderness of the right great toenail associated with dyspigmentation of 5 years' duration. Histopathology revealed a cystic structure with an epithelial lining mostly reminiscent of an isthmus-catagen cyst admixed with the presence of both an intermittent, focal granular layer and an eosinophilic cuticle surrounding pink, laminated keratin, most consistent with a diagnosis of subungual onycholemmal cyst (SOC). It is a rare and distinctive nail abnormality occurring in the dermis of the nail bed. We present a case of an SOC in the toenail mimicking subungual malignant melanoma, which may be an underrecognized and common entity that must be considered when discussing tumors of the nail unit, especially subungual melanoma.

  1. Somatostatin-secreting Pheochromocytoma Mimicking Insulin-dependent Diabetes Mellitus

    PubMed Central

    Hirai, Hiroyuki; Midorikawa, Sanae; Suzuki, Shinichi; Sasano, Hironobu; Watanabe, Tsuyoshi; Satoh, Hiroaki

    2016-01-01

    We herein present the findings of a 42-year-old woman with either adrenal pheochromocytoma or intraadrenal paraganglioma that simultaneously secreted somatostatin, thus mimicking insulin-dependent diabetes mellitus. Pheochromocytoma was clinically diagnosed based on scintigraphy, elevated catecholamine levels, and finally a histopathological analysis of resected specimens. The patient had diabetic ketosis, requiring 40 U insulin for treatment. Following laparoscopic adrenalectomy, insulin therapy was discontinued and the urinary c-peptide levels changed from 5.5-9.0 to 81.3-87.0 μg/day. Histologically, somatostatin immunoreactivity was detected and the somatostatin levels were elevated in the serum-like fluid obtained from the tumor. Clinicians should be aware of the possible occurrence of simultaneous ectopic hormone secretion in patients with pheochromocytoma. PMID:27746437

  2. Somatostatin-secreting Pheochromocytoma Mimicking Insulin-dependent Diabetes Mellitus.

    PubMed

    Hirai, Hiroyuki; Midorikawa, Sanae; Suzuki, Shinichi; Sasano, Hironobu; Watanabe, Tsuyoshi; Satoh, Hiroaki

    We herein present the findings of a 42-year-old woman with either adrenal pheochromocytoma or intraadrenal paraganglioma that simultaneously secreted somatostatin, thus mimicking insulin-dependent diabetes mellitus. Pheochromocytoma was clinically diagnosed based on scintigraphy, elevated catecholamine levels, and finally a histopathological analysis of resected specimens. The patient had diabetic ketosis, requiring 40 U insulin for treatment. Following laparoscopic adrenalectomy, insulin therapy was discontinued and the urinary c-peptide levels changed from 5.5-9.0 to 81.3-87.0 μg/day. Histologically, somatostatin immunoreactivity was detected and the somatostatin levels were elevated in the serum-like fluid obtained from the tumor. Clinicians should be aware of the possible occurrence of simultaneous ectopic hormone secretion in patients with pheochromocytoma.

  3. Recurrent histoplasmosis in AIDS mimicking a colonic carcinoma.

    PubMed

    Aisenberg, G; Marcos, L A; Ogbaa, I

    2009-06-01

    The prevalence rate of lower gastrointestinal bleeding in patients with AIDS is around 2.6%. A 42-year-old woman with AIDS (CD(4) count 9/microL) and recently treated for disseminated histoplasmosis presented to the emergency room with melena, severe anaemia and fever. A colonoscopy showed an umbilicated colonic nodule mimicking a carcinoma of the colon. The biopsy showed intracytoplasmic microorganisms compatible with Histoplasma capsulatum. She had poor compliance to the itraconazole when discharge on previous admission. Despite the fact that colonic histoplasmosis is uncommon, the mortality rate is around 8% and clinicians should be aware of the clinical presentation of histoplasmosis when recur, especially in patients not taking the itraconazole for long-term treatment.

  4. [Amputation neuroma mimicking common bile duct cancer: a case report].

    PubMed

    Koh, Dong Wook; Lee, Woo Jin; Kim, Ji Hoon; Choi, Jun-Il; Kim, Seong Hoon; Hong, Eun Kyung; Park, Joong-Won; Kim, Chang-Min

    2008-07-01

    Amputation neuroma or traumatic neuroma is a tumor-like secondary hyperplasia that may develop after an accidental or surgical trauma. Amputation neuroma of the bile duct has occasionally been reported which occurred in the cystic duct stump late after the cholecystectomy. However, even if the amputation neuroma is suspected in a patient with late-onset jaundice after cholecystectomy, the differential diagnosis from a malignancy is difficult preoperatively. We experienced a case of the amputation neuroma of common bile duct (CBD) developed in a 70-year-old man who presented with a polypoid mass in CBD. He had undergone cholecystectomy 25 years ago and choledochojejunostomy 12 years ago, respectively. We have performed pylorus-preserving pancreatico-duodenectomy (PPPD) under the impression of CBD cancer. He had not been diagnosed of amputation neuroma until having undergone PPPD. We report a case of CBD neuroma mimicking CBD cancer, which was confirmed after PPPD.

  5. Liquid optical phantoms mimicking spectral characteristics of laboratory mouse biotissues

    NASA Astrophysics Data System (ADS)

    Loginova, D. A.; Sergeeva, E. A.; Krainov, A. D.; Agrba, P. D.; Kirillin, M. Yu

    2016-06-01

    Optical phantoms mimicking optical properties of real biotissues in the visible and IR spectral regions are developed based on measurements of the spectral characteristics of ex vivo samples of laboratory mouse biotissues. The phantoms are composed of aqueous solutions of Lipofundin, Indian ink and red ink with different spectral characteristics. The deviations of the measured absorption and scattering coefficients of phantoms in the wavelength range 480 - 580 nm from the corresponding values for real biotissues do not exceed 25% and 2%, respectively. For phantoms in the wavelength region 580 - 880 nm, the deviations of the absorption coefficient do not exceed 40% and the deviations of the scattering coefficient do not exceed 25%. These values, in general, fall within the range of variations for different individual mice of one strain.

  6. Mimicking diffuse supernova antineutrinos with the sun as a source

    SciTech Connect

    Raffelt, G. G.; Rashba, T. I.

    2010-04-15

    Measuring the {nu}-bar{sub e} component of the cosmic diffuse supernova neutrino background (DSNB) is the next ambitious goal for low-energy neutrino astronomy. The largest flux is expected in the lowest accessible energy bin. However, for E {<=} 15 MeV a possible signal can be mimicked by a solar {nu}-bar{sub e} flux that originates from the usual {sup 8}B neutrinos by spin-flavor oscillations. We show that such an interpretation is possible within the allowed range of neutrino electromagnetic transition moments and solar turbulent field strengths and distributions. Therefore, an unambiguous detection of the DSNB requires a significant number of events at E {>=} 15 MeV.

  7. Enterobiasis in ectopic locations mimicking tumor-like lesions.

    PubMed

    Pampiglione, Silvio; Rivasi, Francesco

    2009-01-01

    Both the clinical and the histopathological diagnostic difficulties of oxyuriasis in unusual sites and their importance from a clinical point of view are pointed out. The authors report two ectoptic cases of enterobiasis observed in Northern Italy, one located in a fallopian tube of a 57-year-old woman and the other in a perianal subcutaneous tissue of a 59-year-old man, mimicking tumor-like lesions. The authors take advantage of the occasion to focus the attention of the medical world on this subject, lamenting the scarce importance given to this parasitosis in university courses of medical schools and in medical textbooks as it is incorrectly considered "out-of-fashion."

  8. Giant cystic sacral schwannoma mimicking tarlov cyst: a case report.

    PubMed

    Attiah, Mark A; Syre, Peter P; Pierce, John; Belyaeva, Elizaveta; Welch, William C

    2016-05-01

    To present a rare case of a giant schwannoma of the sacrum mimicking a Tarlov cyst. A 58-year-old woman had a 1-year history of low back pain. MRI revealed a large cystic mass in the sacral canal with bony erosion. Radiological diagnosis of Tarlov cyst was made. The patient underwent surgical treatment for the lesion, which revealed a solid mass. Histopathological examination of the tumor confirmed the diagnosis of schwannoma. The postoperative course was uneventful and the patient has had significant improvement in her pain 1 month postoperatively. Giant cystic schwannoma of the sacrum is a very rare diagnosis overlooked by practitioners for more common cystic etiologies, but its treatment is significantly different. Care should be taken to include this diagnosis in a differential for a cystic sacral mass.

  9. Eosinophilic Cystitis Mimicking Bladder Tumour – A Rare Case Report

    PubMed Central

    D, Manimaran; T M, Karthikeyan; M, Sreenivasulu; V R, Mrinalini; V, Gopinath

    2013-01-01

    A 16–year–old male presented with urinary urgency, a frequency of 4 months duration and intermittent gross haematuria which were there since one month. Eosinophilia was noted in complete blood count and CT KUB with contrast showed a filling defect in the right lateral wall, over the vesicoureteric junction. Cystoscopy revealed a sessile mass lesion over right vesico–ureteric junction, with bullous oedema . Rest of the mucosa was normal. Transurethral resection of lesion was performed and histological examination showed features of eosinophilic cystitis. Patient was treated with corticosteroids, antimicrobial agents and antihistaminics and he is recovering well. We are presenting this case for its rare presentation and its possibility of mimicking a bladder tumour. Biopsy of the lesion was diagnostic and an early treatment showed good results. PMID:24298501

  10. Blood-Mimicking Fluid for Testing Ultrasonic Diagnostic Instrument

    NASA Astrophysics Data System (ADS)

    Tanaka, Kouhei; Yoshida, Tomoji; Sato, Kazuishi; Kondo, Toshio; Yasukawa, Kazuhiro; Miyamoto, Nobuaki; Taniguchi, Masahiko

    2012-07-01

    We present a blood-mimicking fluid (BMF) for the Doppler test object of medical diagnostic instruments. Accurate measurement in a flow Doppler test requires a BMF that has the acoustic velocity and density defined in the International Electrotechnical Commission (IEC) standard, and furthermore, they must be stable over time. To formulate a fluid with the desired density and acoustic velocity, we have developed a new fluid made of glycerine and water-soluble silicone oil. The new BMF includes dispersed polystyrene particles as scatterers. The density of the liquid can be adjusted to maintain it at the same value as that of the polystyrene particles, thus ensuring neutral buoyancy of the particles. The MBF was stable over a period of 2 weeks, during which the density and acoustic velocity did not change.

  11. Dense Deposit Disease Mimicking a Renal Small Vessel Vasculitis.

    PubMed

    Singh, Lavleen; Singh, Geetika; Bhardwaj, Swati; Sinha, Aditi; Bagga, Arvind; Dinda, Amit

    2016-01-01

    Dense deposit disease is caused by fluid-phase dysregulation of the alternative complement pathway and frequently deviates from the classic membranoproliferative pattern of injury on light microscopy. Other patterns of injury described for dense deposit disease include mesangioproliferative, acute proliferative/exudative, and crescentic GN. Regardless of the histologic pattern, C3 glomerulopathy, which includes dense deposit disease and C3 GN, is defined by immunofluorescence intensity of C3c two or more orders of magnitude greater than any other immune reactant (on a 0-3 scale). Ultrastructural appearances distinguish dense deposit disease and C3 GN. Focal and segmental necrotizing glomerular lesions with crescents, mimicking a small vessel vasculitis such as ANCA-associated GN, are a very rare manifestation of dense deposit disease. We describe our experience with this unusual histologic presentation and distinct clinical course of dense deposit disease, discuss the pitfalls in diagnosis, examine differential diagnoses, and review the relevant literature.

  12. Isolated angiitis in the hypothalamus mimicking brain tumor.

    PubMed

    Tsutsumi, Satoshi; Ito, Masanori; Yasumoto, Yukimasa; Kaneda, Kazuhiko

    2008-01-01

    A 64-year-old female presented with exaggerating somnolence without contributory medical and lifestyle histories. She was not aware of any preceding infection or headache. Cerebral magnetic resonance imaging demonstrated an isolated enhanced mass in the hypothalamus without meningeal enhancement. Blood and cerebrospinal fluid examinations showed no significant findings except for hypernatremia and hyperprolactinemia. She underwent an open biopsy via the interhemispheric route. Histological examination revealed marked perivascular lymphocytic aggregation with polyclonal immunostaining both for B and T lymphocytes. No findings suggestive of underlying malignancy were recognized. Extensive work-up aiming at systemic vasculitis and lymphoma revealed no signs of extracranial lesion, so the most probable diagnosis was isolated angiitis in the hypothalamus. Angiitis may originate from the hypothalamus and should be considered in the differential diagnosis of hypothalamic lesion mimicking brain tumor on neuroimaging.

  13. An ideal blood mimicking fluid for doppler ultrasound phantoms.

    PubMed

    Samavat, H; Evans, J A

    2006-10-01

    In order to investigate the problems of detecting tumours by ultrasound it is very important to have a portable Doppler flow test object to use as a standardising tool. The flow Doppler test objects are intended to mimic the flow in human arteries. To make the test meaningful, the acoustic properties of the main test object components (tissue and blood mimic) should match closely the properties of the corresponding human tissues, while the tube should ideally have little influence. The blood mimic should also represent the haemodynamic properties of blood. An acceptable flow test object has been designed to closely mimic blood flow in arteries. We have evaluated the properties of three blood mimicking fluid: two have been described recently in the literature, the third is a local design. One of these has emerged as being particularly well matched to the necessary characteristics for in-vitro work.

  14. Granulomatous prostatitis after intravesical immunotherapy mimicking prostate cancer.

    PubMed

    Białek, Waldemar; Rudzki, Sławomir; Iberszer, Paweł; Wronecki, Lech

    2016-12-01

    Intravesical immunotherapy with attenuated strains of Mycobacterium bovis is a widely used therapeutic option in patients with non-muscle-invasive transitional cell carcinoma of the bladder. A rare complication of intravesical therapy with the Bacillus Calmette-Guérin vaccine is granulomatous prostatitis, which due to increasing levels of prostate-specific antigen and abnormalities found in transrectal examination of the prostate may suggest concomitant prostate cancer. A case of extensive granulomatous prostatitis in a 61-year-old patient which occurred after the first course of a well-tolerated Bacillus Calmette-Guérin therapy is presented. Due to abnormalities found in rectal examination and an abnormal transrectal ultrasound image of the prostate with extensive infiltration mimicking neoplastic hyperplasia a core biopsy of the prostate was performed. Histopathological examination revealed inflammatory infiltration sites of tuberculosis origin.

  15. Surgicel® granuloma mimicking ovarian cancer: A case report

    PubMed Central

    Cormio, Luigi; Cormio, Gennaro; Di Fino, Giuseppe; Scavone, Carmen; Sanguedolce, Francesca; Loizzi, Vera; Carrieri, Giuseppe

    2016-01-01

    Surgicel® is an absorbable sterile mesh composed of oxidized cellulose that is used to control intraoperative capillary or venous bleeding, due to its capacity to bind hemoglobin, thus allowing the formation of an artificial clot. In the present study, a large granuloma mimicking ovarian cancer, which developed following placement of a Surgicel® sponge during a combined pubovaginal sling procedure and cystocele repair, is reported. The aim of the present case report is to emphasize the fact that hemostatic measures should be removed following their use, and to alert surgeons to the risk of using and leaving in situ oxidized cellulose. Furthermore, accurate evaluation of the surgical history of the patient should always be performed prior to attempting surgery. PMID:27446398

  16. Enzyme-Mimicking properties of silicates and other minerals

    NASA Astrophysics Data System (ADS)

    Siegel, B. Z.; Siegel, S. M.

    The adsorptive and/or catalytic properties of clays, silicates in general, and other minerals are well known. More recently, their probable role in prebiotic syntheses of bio-organic compounds has become a matter of record. We demonstrate that, in addition to their role in de novo formation of important biomolecules, clays, micas, fibrous silicates and other minerals mimick the activities of contemporary enzymes including oxidases, esterases, phosphatases and glucosidases. The existence of such capabilities in substances likely to be represented on the surfaces of Earth-like planets may offer a challenge to the technology and design of remote life detection systems which must then distinguish between bona fide biological chemistry and mineral-base pseudometabolism. It also raises questions about the importance of mineral surfaces in post-mortem transformations of organic metabolites in our own biosphere.

  17. A Rare Presentation of Peritoneal Tuberculosis Mimicking Malignancy

    PubMed Central

    Swe, Thein; Naing, Akari Thein; Phyo, Zaw Win; Thwin, Malar

    2016-01-01

    Our search of literature revealed combined elevations of serum cancer antigen 125 levels and rheumatoid factor levels in a patient with peritoneal tuberculosis has rarely been reported. Thus, we describe the case of a 63-year-old female with large abdominal ascites and malignancy was ruled out with biopsy. High levels of serum cancer antigen and rheumatoid factor were noted. Physicians should be aware that tuberculosis infection could induce elevation of rheumatoid factor levels in the absence of rheumatologic symptoms or disease. A high index of suspicion is required because peritoneal tuberculosis is a great mimicker of other abdominal pathology, especially intraabdominal malignancies and can mislead physicians to undergo unnecessary interventions. PMID:27900335

  18. Granulomatous prostatitis after intravesical immunotherapy mimicking prostate cancer

    PubMed Central

    Rudzki, Sławomir; Iberszer, Paweł; Wronecki, Lech

    2016-01-01

    Intravesical immunotherapy with attenuated strains of Mycobacterium bovis is a widely used therapeutic option in patients with non-muscle-invasive transitional cell carcinoma of the bladder. A rare complication of intravesical therapy with the Bacillus Calmette-Guérin vaccine is granulomatous prostatitis, which due to increasing levels of prostate-specific antigen and abnormalities found in transrectal examination of the prostate may suggest concomitant prostate cancer. A case of extensive granulomatous prostatitis in a 61-year-old patient which occurred after the first course of a well-tolerated Bacillus Calmette-Guérin therapy is presented. Due to abnormalities found in rectal examination and an abnormal transrectal ultrasound image of the prostate with extensive infiltration mimicking neoplastic hyperplasia a core biopsy of the prostate was performed. Histopathological examination revealed inflammatory infiltration sites of tuberculosis origin. PMID:28138411

  19. Mimicking biological stress-strain behaviour with synthetic elastomers.

    PubMed

    Vatankhah-Varnosfaderani, Mohammad; Daniel, William F M; Everhart, Matthew H; Pandya, Ashish A; Liang, Heyi; Matyjaszewski, Krzysztof; Dobrynin, Andrey V; Sheiko, Sergei S

    2017-09-28

    Despite the versatility of synthetic chemistry, certain combinations of mechanical softness, strength, and toughness can be difficult to achieve in a single material. These combinations are, however, commonplace in biological tissues, and are therefore needed for applications such as medical implants, tissue engineering, soft robotics, and wearable electronics. Present materials synthesis strategies are predominantly Edisonian, involving the empirical mixing of assorted monomers, crosslinking schemes, and occluded swelling agents, but this approach yields limited property control. Here we present a general strategy for mimicking the mechanical behaviour of biological materials by precisely encoding their stress-strain curves in solvent-free brush- and comb-like polymer networks (elastomers). The code consists of three independent architectural parameters-network strand length, side-chain length and grafting density. Using prototypical poly(dimethylsiloxane) elastomers, we illustrate how this parametric triplet enables the replication of the strain-stiffening characteristics of jellyfish, lung, and arterial tissues.

  20. Disulfiram ethanol reaction mimicking anaphylactic, cardiogenic, and septic shock.

    PubMed

    Bourcier, Simon; Mongardon, Nicolas; Daviaud, Fabrice; Moachon, Laurence; Arnould, Marc-Antoine; Perruche, Franck; Pène, Frédéric; Cariou, Alain

    2013-01-01

    Shock is a common reason for medical intensive care unit admission, with septic and cardiogenic accounting for most of the etiologies. However, the potential severity of adverse side effects of drugs indicates that any medication should be carefully scrutinized for potential pharmacokinetic and pharmacodynamic interactions that may result. We herein report the case of a life-threatening shock mimicking successively anaphylactic, cardiogenic, and septic shock, which was finally related to disulfiram ethanol reaction. Indeed, disulfiram ethanol reaction is known to provoke unpleasant symptoms through vasodilatation in various organs. However, extreme manifestations of vasodilatory shock may lead to circulatory failure and lactic acidosis. Because of large prevalence of alcoholism and disulfiram medication, emergency physicians and medical specialists should be aware of this life-threatening condition, with its misleading presentation.

  1. Adenoid Cystic Carcinoma Mimicking an Oroantral Fistula: A Case Report

    PubMed Central

    Monteiro, Bárbara Vanessa de Brito; Grempel, Rafael Grotta; Gomes, Daliana Queiroga de Castro; Godoy, Gustavo Pina; Miguel, Márcia Cristina da Costa

    2013-01-01

    Introduction Adenoid cystic carcinoma (ACC) is one of the most frequent malignant salivary gland tumors, which commonly affects the minor salivary glands of the mouth and is rare in the nose and paranasal sinuses. In the maxillary sinus, ACC can mimic inflammatory diseases and has a poor prognosis. Objective To report a case of a 50-year-old man with ACC of the maxillary sinus whose clinical findings in the alveolar ridge mimicked an oroantral fistula. Case Report An excisional biopsy was performed and histopathologic analysis revealed ACC. Lung metastases and residual tumor in the maxillary sinus were detected by imaging methods. In view of the poor general health of the patient, no new surgical intervention was performed and he was only treated by radiotherapy and follow-up. Conclusion Although rare in the maxillary sinus, ACC should be included in the differential diagnosis of lesions affecting this site. PMID:25992095

  2. Tissue-mimicking gel phantoms for thermal therapy studies.

    PubMed

    Dabbagh, Ali; Abdullah, Basri Johan Jeet; Ramasindarum, Chanthiriga; Abu Kasim, Noor Hayaty

    2014-10-01

    Tissue-mimicking phantoms that are currently available for routine biomedical applications may not be suitable for high-temperature experiments or calibration of thermal modalities. Therefore, design and fabrication of customized thermal phantoms with tailored properties are necessary for thermal therapy studies. A multitude of thermal phantoms have been developed in liquid, solid, and gel forms to simulate biological tissues in thermal therapy experiments. This article is an attempt to outline the various materials and techniques used to prepare thermal phantoms in the gel state. The relevant thermal, electrical, acoustic, and optical properties of these phantoms are presented in detail and the benefits and shortcomings of each type are discussed. This review could assist the researchers in the selection of appropriate phantom recipes for their in vitro study of thermal modalities and highlight the limitations of current phantom recipes that remain to be addressed in further studies. © The Author(s) 2014.

  3. Oropharyngeal trauma mimicking a first branchial cleft anomaly.

    PubMed

    Larem, Aisha; Sheikh, Rashid; Al Qahtani, Abdulsalam; Khais, Frat; Ganesan, Shanmugam; Haidar, Hassan

    2016-06-01

    We present a unique and challenging case of a remnant foreign body that presented to us in a child disguised as a strongly suspected congenital branchial cleft anomaly. This case entailed oropharyngeal trauma, with a delayed presentation as a retroauricular cyst accompanied by otorrhea that mimicked the classic presentation of an infected first branchial cleft anomaly. During surgical excision of the presumed branchial anomaly, a large wooden stick was found in the tract. The diagnostic and therapeutic obstacles in the management of such cases are highlighted. In addition to exploring the existing literature, we retrospectively analyzed a plausible explanation of the findings of this case. Laryngoscope, 126:E224-E226, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  4. Multi-modality tissue-mimicking phantom for thermal therapy.

    PubMed

    McDonald, Mark; Lochhead, Shanna; Chopra, Rajiv; Bronskill, Michael J

    2004-07-07

    A tissue-mimicking phantom material has been developed for use with thermal therapy devices and techniques. This material has magnetic resonance properties (primarily T2) which change drastically upon thermal coagulation, enabling its use for device characterization and treatment verification using simple T2-weighted imaging techniques. The coagulation temperature of the phantom can be changed from 50-60 degrees C by adjusting the pH from 4.3 to 4.7. The energy absorption properties can be adjusted to match the acoustical and optical properties of tissues. T2 relaxation measurements are provided as a function of temperature, along with T2-weighted MR images to illustrate the visualization of heating patterns. A complete recipe for fabricating phantoms is provided.

  5. Mesenteric lymphangioma mimicking a cystic ovarian mass on imaging.

    PubMed

    Hitzerd, Emilie; van Hamont, Dennis; Pijnenborg, Johanna M A

    2016-02-01

    Pelvic cystic masses are frequently observed in women. Most lesions are benign and of ovarian origin. However, non-ovarian lesions can be easily confused with cystic ovarian masses on imaging, which hampers diagnostic and therapeutic management. In this report, a rare case of mesenteric lymphangioma mimicking an ovarian cystic mass, discovered as an incidental finding on orthopaedic MRI in an adult female, is presented. The report highlights the sometimes difficult diagnostic process of pelvic cystic masses, due to an extensive differential diagnosis and the fact that imaging is often inconclusive. Even though most cystic masses are of ovarian origin, non-ovarian causes can mimic ovarian masses and should be considered as differential diagnoses. Surgical exploration may be necessary to exclude malignant causes. 2016 BMJ Publishing Group Ltd.

  6. A salivary gland adenocarcinoma mimicking a microcystic adnexal carcinoma.

    PubMed

    Basile, John R; Lin, Yi-Ling

    2010-04-01

    The microcystic adnexal carcinoma (MAC) is a rare, slow-growing but locally aggressive neoplasm arising in the midface and lips of middle-aged adults. The MAC is histologically characterized by deeply infiltrating nests and islands of basaloid or squamous cells forming cysts and ductal structures, proliferating in a dense sclerotic stroma and occasionally exhibiting perineural invasion. We describe a salivary gland adenocarcinoma arising in the lower lip, characterized by ductal structures and cords, 3-5 cell layers in thickness, set in a dense fibrous stroma and also invading nerves, thus mimicking a MAC in both its clinical and its histopathologic appearance. The diagnostic dilemma presented by this lesion is discussed, along with a differential diagnosis and brief review of the literature.

  7. Huge uterine-cervical diverticulum mimicking as a cyst.

    PubMed

    Chufal, S; Thapliyal, Naveen; Gupta, Manoj; Pangtey, Nirmal

    2012-01-01

    Here we report an incidental huge uterine-cervical diverticulum from a total abdominal hysterectomy specimen in a perimenopausal woman who presented with acute abdominal pain. The diverticulum was mimicking with various cysts present in the lateral side of the female genital tract. Histopathological examination confirmed this to be a cervical diverticulum with communication to uterine cavity through two different openings. They can attain huge size if left ignored for long duration and present a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, diverticula should also be included as a differential diagnosis. Its histopathological confirmation also highlights that diverticula can present as an acute abdomen, requiring early diagnosis with appropriate timely intervention. Immunohistochemistry CD 10 has also been used to differentiate it from a mesonephric cyst.

  8. Optofluidic phantom mimicking optical properties of porcine livers

    SciTech Connect

    Long, Ruiqi; King, Travis; Akl, Tony; Ericson, Milton Nance; Wilson, Mark A.; Cote, Gerard L.; McShane, Michael J.

    2011-01-01

    One strategy for assessing efficacy of a liver transplant is to monitor perfusion and oxygenation after transplantation. An implantable optical sensor is being developed to overcome inadequacies of current monitoring approaches. To facilitate sensor design while minimizing animal use, a polydimethylsiloxane (PDMS)-based liver phantom was developed to mimic the optical properties of porcine liver in the 630-1000 nm wavelength range and the anatomical geometry of liver parenchyma. Using soft lithography to construct microfluidic channels in pigmented elastomer enabled the 2D approximation of hexagonal liver lobules with 15mm sinusoidal channels, which will allow perfusion with blood-mimicking fluids to facilitate the development of the liver perfusion and oxygenation monitoring system.

  9. Teflon granulomas mimicking cerebellopontine angle tumors following microvascular decompression.

    PubMed

    Deep, Nicholas L; Graffeo, Christopher S; Copeland, William R; Link, Michael J; Atkinson, John L; Neff, Brian A; Raghunathan, Aditya; Carlson, Matthew L

    2017-03-01

    To report two patients with a history of microvascular decompression (MVD) for hemifacial spasm who presented with Teflon granulomas (TG) mimicking cerebellopontine angle (CPA) tumors and to perform a systematic review of the English-language literature. Case series at a single tertiary academic referral center and systematic review. Retrospective chart review with analysis of clinical, radiological, and histopathological findings. Systematic review using PubMed, Embase, MEDLINE, and Web of Science databases. Two patients with large skull base TGs mimicking CPA tumors clinically and radiographically were managed at the authors' institution. The first presented 4 years after MVD with asymmetrical sensorineural hearing loss, multiple progressive cranial neuropathies, and brainstem edema due to a growing TG. Reoperation with resection of the granuloma confirmed a foreign-body reaction consisting of multinucleated giant cells containing intracytoplasmic Teflon particles. The second patient presented 11 years after MVD with asymmetrical sensorineural hearing loss and recurrent hemifacial spasm. No growth was noted over 2 years, and the patient has been managed expectantly. Only one prior case of TG after MVD for hemifacial spasm has been reported in the English literature. TG is a rare complication of MVD for hemifacial spasm. The diagnosis should be suspected in patients presenting with a new-onset enhancing mass of the CPA after MVD, even when performed decades earlier. A thorough clinical and surgical history is critical toward establishing an accurate diagnosis to guide management and prevent unnecessary morbidity. Surgical intervention is not required unless progressive neurologic complications ensue. 4 Laryngoscope, 127:715-719, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  10. Primary scattered multifocal melanocytomas in spinal canal mimicking neurofibromatosis.

    PubMed

    Yang, Chenlong; Fang, Jingyi; Li, Guang; Yang, Jun; Xu, Yulun

    2016-08-01

    Meningeal melanocytoma is an extremely rare pigmented tumor derived from leptomeningeal melanocytes. By and large, it is considered to be a well-differentiated and slow-growing benign lesion. Generally, meningeal melanocytomas are solitary lesions, and the occurrence of the primary multifocal form in the central nervous system is exceedingly rare; it has been previously reported in only six cases. The present report illustrates a 41-year-old woman with primary multifocal meningeal melanocytoma in the spinal canal. Contrary to earlier reports, the tumors presented with a scattered appearance mimicking neurofibromatosis. This study is a case report and review of literature. On admission, the cerebral magnetic resonance images of the patient were normal, whereas the spinal magnetic resonance images showed scattered multifocal nodules mimicking neurofibromatosis. Surgical resection of the responsible lesions was scheduled. In addition to this case presentation, relevant previous reports were reviewed, and the challenging diagnosis, management, and prognosis of meningeal melanocytoma are discussed. Gross total resection of the two largest lesions was achieved, and histopathological examinations confirmed the diagnosis. Despite the benign histopathological findings, the patient had an aggressive clinical course. On follow-up at 18 months after surgery, she succumbed to the disease. Clinicians should be alert to a potential aggressive clinical course of meningeal melanocytoma, despite its benign histopathological nature. Of particular note is multifocality and diffuse leptomeningeal hyperpigmentation, which may suggest a poor prognosis. A combined treatment including surgical resection and adjuvant radiotherapy should be considered, and long-term close follow-up is necessary. Copyright © 2016. Published by Elsevier Inc.

  11. Acoustical characterization of polysaccharide polymers tissue-mimicking materials.

    PubMed

    Cuccaro, Rugiada; Musacchio, Chiara; Giuliano Albo, P Alberto; Troia, Adriano; Lago, Simona

    2015-02-01

    Tissue-mimicking phantoms play a crucial role in medical ultrasound research because they can simulate biological soft tissues. In last years, many types of polymeric tissues have been proposed and characterized from an acoustical and a thermal point of view, but, rarely, a deep discussion about the quality of the measurements, in terms of the uncertainty evaluation, has been reported. In this work, considering the necessity to develop laboratory standards for the measurement of ultrasonic exposure and dose quantities, a detailed description of the experimental apparatuses for the sound speed and the attenuation coefficient measurements is given, focusing the attention on the uncertainty evaluation both of the results and analysis algorithms. In particular, this algorithm reveals a novel empirical relation, fixing a limit to the energy content (therefore limits the number of cycles) of the three parts in which the authors have proposed to divide the acoustical signal. Furthermore, the realisation of multi-components phantoms, Agar and Phytagel based tissue-mimicking gels along with others long chain molecules (dextrane or polyvinyl alcohol) and scattering materials (silicon carbide and kieselguhr) are investigated. This paper reports accurate speed of sound and attenuation coefficient measurements. Speed of sound is measured by a pulse-echo technique in far-field condition, using an optical glass buffer rod; while attenuation coefficient is determined by an insertion technique, using demineralized water as reference material. The experimental sound speed results are subjected to an overall estimated relative uncertainty of about 1.5% and the attenuation coefficient uncertainty is less than 2.5%. For the development of laboratory standards, a detailed analysis of the measurement uncertainty is fundamental to make sample properties comparable. The authors believe this study could represent the right direction to make phantoms characterizations referable and traceable.

  12. Toward XML Representation of NSS Simulation Scenario for Mission Scenario Exchange Capability

    DTIC Science & Technology

    2003-09-01

    Combat XXI Program...........................13 2. Transition NSS to a Java Environment ...........................................13 3. Shift to an...and Reconnaissance IV&V Independent Verification and Validation xvi JCS Joint Chiefs of Staff JDOM Java Document Object Model...Scenario .xml NSS Simulation Scenario .xsd NSS Simulation Scenario . java NSS Simulation Scenario Text ? XML .xslt NSS Simulation

  13. Web Based Tool for Mission Operations Scenarios

    NASA Technical Reports Server (NTRS)

    Boyles, Carole A.; Bindschadler, Duane L.

    2008-01-01

    A conventional practice for spaceflight projects is to document scenarios in a monolithic Operations Concept document. Such documents can be hundreds of pages long and may require laborious updates. Software development practice utilizes scenarios in the form of smaller, individual use cases, which are often structured and managed using UML. We have developed a process and a web-based scenario tool that utilizes a similar philosophy of smaller, more compact scenarios (but avoids the formality of UML). The need for a scenario process and tool became apparent during the authors' work on a large astrophysics mission. It was noted that every phase of the Mission (e.g., formulation, design, verification and validation, and operations) looked back to scenarios to assess completeness of requirements and design. It was also noted that terminology needed to be clarified and structured to assure communication across all levels of the project. Attempts to manage, communicate, and evolve scenarios at all levels of a project using conventional tools (e.g., Excel) and methods (Scenario Working Group meetings) were not effective given limitations on budget and staffing. The objective of this paper is to document the scenario process and tool created to offer projects a low-cost capability to create, communicate, manage, and evolve scenarios throughout project development. The process and tool have the further benefit of allowing the association of requirements with particular scenarios, establishing and viewing relationships between higher- and lower-level scenarios, and the ability to place all scenarios in a shared context. The resulting structured set of scenarios is widely visible (using a web browser), easily updated, and can be searched according to various criteria including the level (e.g., Project, System, and Team) and Mission Phase. Scenarios are maintained in a web-accessible environment that provides a structured set of scenario fields and allows for maximum

  14. Web Based Tool for Mission Operations Scenarios

    NASA Technical Reports Server (NTRS)

    Boyles, Carole A.; Bindschadler, Duane L.

    2008-01-01

    A conventional practice for spaceflight projects is to document scenarios in a monolithic Operations Concept document. Such documents can be hundreds of pages long and may require laborious updates. Software development practice utilizes scenarios in the form of smaller, individual use cases, which are often structured and managed using UML. We have developed a process and a web-based scenario tool that utilizes a similar philosophy of smaller, more compact scenarios (but avoids the formality of UML). The need for a scenario process and tool became apparent during the authors' work on a large astrophysics mission. It was noted that every phase of the Mission (e.g., formulation, design, verification and validation, and operations) looked back to scenarios to assess completeness of requirements and design. It was also noted that terminology needed to be clarified and structured to assure communication across all levels of the project. Attempts to manage, communicate, and evolve scenarios at all levels of a project using conventional tools (e.g., Excel) and methods (Scenario Working Group meetings) were not effective given limitations on budget and staffing. The objective of this paper is to document the scenario process and tool created to offer projects a low-cost capability to create, communicate, manage, and evolve scenarios throughout project development. The process and tool have the further benefit of allowing the association of requirements with particular scenarios, establishing and viewing relationships between higher- and lower-level scenarios, and the ability to place all scenarios in a shared context. The resulting structured set of scenarios is widely visible (using a web browser), easily updated, and can be searched according to various criteria including the level (e.g., Project, System, and Team) and Mission Phase. Scenarios are maintained in a web-accessible environment that provides a structured set of scenario fields and allows for maximum

  15. Innovations in science and scenarios for assessment

    DOE PAGES

    Kunkel, Kenneth E.; Moss, Richard; Parris, Adam

    2015-08-29

    Scenarios for the Third National Climate Assessment (NCA3) were produced for physical climate and sea level rise with substantial input from disciplinary and regional experts. These scenarios underwent extensive review and were published as NOAA Technical Reports. For land use/cover and socioeconomic conditions, scenarios already developed by other agencies were specified for use in the NCA3. Efforts to enhance participatory scenario planning as an assessment activity were pursued, but with limited success. Issues and challenges included the timing of availability of scenarios, the need for guidance in use of scenarios, the need for approaches to nest information within multiple scalesmore » and sectors, engagement and collaboration of end users in scenario development, and development of integrated scenarios. Future assessments would benefit from an earlier start to scenarios development, the provision of training in addition to guidance documents, new and flexible approaches for nesting information, ongoing engagement and advice from both scientific and end user communities, and the development of consistent and integrated scenarios.« less

  16. Innovations in science and scenarios for assessment

    SciTech Connect

    Kunkel, Kenneth E.; Moss, Richard; Parris, Adam

    2015-08-29

    Scenarios for the Third National Climate Assessment (NCA3) were produced for physical climate and sea level rise with substantial input from disciplinary and regional experts. These scenarios underwent extensive review and were published as NOAA Technical Reports. For land use/cover and socioeconomic conditions, scenarios already developed by other agencies were specified for use in the NCA3. Efforts to enhance participatory scenario planning as an assessment activity were pursued, but with limited success. Issues and challenges included the timing of availability of scenarios, the need for guidance in use of scenarios, the need for approaches to nest information within multiple scales and sectors, engagement and collaboration of end users in scenario development, and development of integrated scenarios. Future assessments would benefit from an earlier start to scenarios development, the provision of training in addition to guidance documents, new and flexible approaches for nesting information, ongoing engagement and advice from both scientific and end user communities, and the development of consistent and integrated scenarios.

  17. Innovations in science and scenarios for assessment.

    PubMed

    Kunkel, Kenneth E; Moss, Richard; Parris, Adam

    Scenarios for the Third National Climate Assessment (NCA3) were produced for physical climate and sea level rise with substantial input from disciplinary and regional experts. These scenarios underwent extensive review and were published as NOAA Technical Reports. For land use/cover and socioeconomic conditions, scenarios already developed by other agencies were specified for use in the NCA3. Efforts to enhance participatory scenario planning as an assessment activity were pursued, but with limited success. Issues and challenges included the timing of availability of scenarios, the need for guidance in use of scenarios, the need for approaches to nest information within multiple scales and sectors, engagement and collaboration of end users in scenario development, and development of integrated scenarios. Future assessments would benefit from an earlier start to scenarios development, the provision of training in addition to guidance documents, new and flexible approaches for nesting information, ongoing engagement and advice from both scientific and end user communities, and the development of consistent and integrated scenarios.

  18. Innovations in science and scenarios for assessment

    SciTech Connect

    Kunkel, Kenneth E.; Moss, Richard; Parris, Adam

    2015-08-29

    Scenarios for the Third National Climate Assessment (NCA3) were produced for physical climate and sea level rise with substantial input from disciplinary and regional experts. These scenarios underwent extensive review and were published as NOAA Technical Reports. For land use/cover and socioeconomic conditions, scenarios already developed by other agencies were specified for use in the NCA3. Efforts to enhance participatory scenario planning as an assessment activity were pursued, but with limited success. Issues and challenges included the timing of availability of scenarios, the need for guidance in use of scenarios, the need for approaches to nest information within multiple scales and sectors, engagement and collaboration of end users in scenario development, and development of integrated scenarios. Future assessments would benefit from an earlier start to scenarios development, the provision of training in addition to guidance documents, new and flexible approaches for nesting information, ongoing engagement and advice from both scientific and end user communities, and the development of consistent and integrated scenarios.

  19. The narcissistic scenarios of parenthood.

    PubMed

    Manzano, J; Palacio Espasa, F; Zilkha, N

    1999-06-01

    The authors begin by pointing out that Freud always considered parent-child relations in terms of the child's psychic development and took little account of the parents' experience of the relationship and its psychic effects on them. They recall Freud's distinction between the anaclitic and narcissistic modes of relationship and show how these are unconsciously embodied and enacted in varying proportions in the cases observed in their own clinical practice of therapeutic consultations with parents and young children. After a review of the relevant psychoanalytic literature, the authors present their concept of the narcissistic scenarios of parenthood, which include parental projection on to the child, parental counter-identification, a specific aim and a relational dynamic that is acted out. Depending on the individual situation, the effects may help to structure the developing psyche or, if the narcissistic element is excessive, they may be pathological. The authors consider the literature on the application of psychoanalysis to therapeutic interventions with parents and children, stressing the technical importance of establishing a therapeutic focus. These ideas are illustrated by a detailed case history showing the interaction between a mother and a 4-year-old girl and how it was modified by a short therapy. The differences between interpretation in this situation and in the classical psychoanalytic setting are explained, and the paper ends with some comments on the transmission of psychic elements from generation to generation.

  20. Agricultural Baseline (BL0) scenario

    DOE Data Explorer

    Davis, Maggie R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000181319328); Hellwinckel, Chad M [University of Tennessee] (ORCID:0000000173085058); Eaton, Laurence [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000312709626); Turhollow, Anthony [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000228159350); Brandt, Craig [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000214707379); Langholtz, Matthew H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000281537154)

    2016-07-13

    Scientific reason for data generation: to serve as the reference case for the BT16 volume 1 agricultural scenarios. The agricultural baseline runs from 2015 through 2040; a starting year of 2014 is used. Date the data set was last modified: 02/12/2016 How each parameter was produced (methods), format, and relationship to other data in the data set: simulation was developed without offering a farmgate price to energy crops or residues (i.e., building on both the USDA 2015 baseline and the agricultural census data (USDA NASS 2014). Data generated are .txt output files by year, simulation identifier, county code (1-3109). Instruments used: POLYSYS (version POLYS2015_V10_alt_JAN22B) supplied by the University of Tennessee APAC The quality assurance and quality control that have been applied: • Check for negative planted area, harvested area, production, yield and cost values. • Check if harvested area exceeds planted area for annuals. • Check FIPS codes.

  1. Nanofibrous heparin and heparin-mimicking multilayers as highly effective endothelialization and antithrombogenic coatings.

    PubMed

    Nie, Chuanxiong; Ma, Lang; Cheng, Chong; Deng, Jie; Zhao, Changsheng

    2015-03-09

    Combining the advantages of the fibrous nanostructure of carbon nanotubes (CNTs) and the bioactivities of heparin/heparin-mimicking polyanions, functional nanofibrous heparin or heparin-mimicking multilayers were constructed on PVDF membrane with highly promoted endothelialization and antithrombogenic activities. Oxidized CNT (oCNT) was first functionalized with water-soluble chitosan (polycation), then enwrapped with heparin or a typical sulfonated heparin-mimicking polymers (poly(sodium 4-styrenesulfonate-co-sodium methacrylate)) to construct the multilayers. Then, the surface-deposited multilayers were constructed via electrostatic layer-by-layer assembly of the functionalized oCNTs. The scanning electron microscope and atom force microscope images confirmed that the coated multilayers exhibited nanofibrous and porous structure. The live/dead cell staining and cell viability assay results indicated that the coated nanofibrous multilayers had excellent compatibility with endothelial cells. The cell morphology observation further confirmed the promotion ability of surface endothelialization due to the coated heparin/heparin-mimicking multilayers. Further systematical evaluation on blood compatibility revealed that the surface heparin/heparin-mimicking multilayer-coated membranes also had significantly improved blood compatibility including restrained platelet adhesion and activation, prolonged blood clotting times, and inhibited activation of coagulation and complement factors. In summary, the proposed nanofibrous multilayers integrated endothelialization and antithrombogenic properties; meanwhile, the heparin-mimicking coating validated comparable performances as heparin coating. Herein, it is expected that the surface coating of nanofibrous multilayers, especially the facilely constructed heparin-mimicking coating, may have great application potential in biomedical fields.

  2. Transportation accident scenarios for commercial spent fuel

    SciTech Connect

    Wilmot, E L

    1981-02-01

    A spectrum of high severity, low probability, transportation accident scenarios involving commercial spent fuel is presented together with mechanisms, pathways and quantities of material that might be released from spent fuel to the environment. These scenarios are based on conclusions from a workshop, conducted in May 1980 to discuss transportation accident scenarios, in which a group of experts reviewed and critiqued available literature relating to spent fuel behavior and cask response in accidents.

  3. Renormalization-group improved inflationary scenarios

    NASA Astrophysics Data System (ADS)

    Pozdeeva, E. O.; Vernov, S. Yu.

    2017-03-01

    The possibility to construct an inflationary scenario for renormalization-group improved potentials corresponding to the Higgs sector of quantum field models is investigated. Taking into account quantum corrections to the renormalization-group potential which sums all leading logs of perturbation theory is essential for a successful realization of the inflationary scenario, with very reasonable parameters values. The scalar electrodynamics inflationary scenario thus obtained are seen to be in good agreement with the most recent observational data.

  4. MIOSAT Mission Scenario and Design

    NASA Astrophysics Data System (ADS)

    Agostara, C.; Dionisio, C.; Sgroi, G.; di Salvo, A.

    2008-08-01

    MIOSAT ("Mssione Ottica su microSATellite") is a low-cost technological / scientific microsatellite mission for Earth Observation, funded by Italian Space Agency (ASI) and managed by a Group Agreement between Rheinmetall Italia - B.U. Spazio - Contraves as leader and Carlo Gavazzi Space as satellite manufacturer. Several others Italians Companies, SME and Universities are involved in the development team with crucial roles. MIOSAT is a microsatellite weighting around 120 kg and placed in a 525 km altitude sun-synchronuos circular LEO orbit. The microsatellite embarks three innovative optical payloads: Sagnac multi spectral radiometer (IFAC-CNR), Mach Zehender spectrometer (IMM-CNR), high resolution pancromatic camera (Selex Galileo). In addition three technological experiments will be tested in-flight. The first one is an heat pipe based on Marangoni effect with high efficiency. The second is a high accuracy Sun Sensor using COTS components and the last is a GNSS SW receiver that utilizes a Leon2 processor. Finally a new generation of 28% efficiency solar cells will be adopted for the power generation. The platform is highly agile and can tilt along and cross flight direction. The pointing accuracy is in the order of 0,1° for each axe. The pointing determination during images acquisition is <0,02° for the axis normal to the boresight and 0,04° for the boresight. This paper deals with MIOSAT mission scenario and definition, highlighting trade-offs for mission implementation. MIOSAT mission design has been constrained from challenging requirements in terms of satellite mass, mission lifetime, instrument performance, that have implied the utilization of satellite agility capability to improve instruments performance in terms of S/N and resolution. The instruments provide complementary measurements that can be combined in effective ways to exploit new applications in the fields of atmosphere composition analysis, Earth emissions, antropic phenomena, etc. The Mission

  5. The unfolding: scenario planning in nursing.

    PubMed

    Woude, Diana Vander; Damgaard, Gloria; Hegge, Margaret J; Soholt, Deb; Bunkers, Sandra Schmidt

    2003-01-01

    An interdisciplinary consortium organized a group to explore the meaning and the future of nursing in South Dakota using scenario planning. This column provides a general description of the four scenarios that emerged, some observations about how they might evolve, comments on their implications, and first-person stories, as told by fictitious residents. The process of scenario planning is connected to nursing science by explicating how five lessons of scenario planning are linked with Parse's human becoming concepts of creative imagining, glimpsing the paradoxical, and affirming personal becoming.

  6. From Scenarios to Test Implementations Via Promela

    NASA Astrophysics Data System (ADS)

    Ulrich, Andreas; Alikacem, El-Hachemi; Hallal, Hesham H.; Boroday, Sergiy

    We report on a tool for generating executable concurrent tests from scenarios specified as message sequence charts. The proposed approach features three steps: 1) Deriving a MSC test implementation from a MSC scenario, 2) Mapping the test implementation into a Promela model, 3) Generating executable test scripts in Java. The generation of an intermediate Promela model allows for model-checking to inspect the test implementation for properties like soundness, fault detection power as well as for consistency checking between different test scenarios. Moreover decoupling the executable test scripts from the scenario specification makes it possible to use different backend code generators to support other scripting languages when needed.

  7. Study of ultrasound stiffness imaging methods using tissue mimicking phantoms.

    PubMed

    Manickam, Kavitha; Machireddy, Ramasubba Reddy; Seshadri, Suresh

    2014-02-01

    A pilot study was carried out to investigate the performance of ultrasound stiffness imaging methods namely Ultrasound Elastography Imaging (UEI) and Acoustic Radiation Force Impulse (ARFI) Imaging. Specifically their potential for characterizing different classes of solid mass lesions was analyzed using agar based tissue mimicking phantoms. Composite tissue mimicking phantom was prepared with embedded inclusions of varying stiffness from 50 kPa to 450 kPa to represent different stages of cancer. Acoustic properties such as sound speed, attenuation coefficient and acoustic impedance were characterized by pulse echo ultrasound test at 5 MHz frequency and they are ranged from (1564 ± 88 to 1671 ± 124 m/s), (0.6915 ± 0.123 to 0.8268 ± 0.755 db cm(-1)MHz(-1)) and (1.61 × 10(6) ± 0.127 to 1.76 × 10(6) ± 0.045 kg m(-2)s(-1)) respectively. The elastic property Young's Modulus of the prepared samples was measured by conducting quasi static uni axial compression test under a strain rate of 0.5mm/min upto 10 % strain, and the values are from 50 kPa to 450 kPa for a variation of agar concentration from 1.7% to 6.6% by weight. The composite phantoms were imaged by Siemens Acuson S2000 (Siemens, Erlangen, Germany) machine using linear array transducer 9L4 at 8 MHz frequency; strain and displacement images were collected by UEI and ARFI. Shear wave velocity 4.43 ± 0.35 m/s was also measured for high modulus contrast (18 dB) inclusion and X.XX m/s was found for all other inclusions. The images were pre processed and parameters such as Contrast Transfer Efficiency and lateral image profile were computed and reported. The results indicate that both ARFI and UEI represent the abnormalities better than conventional US B mode imaging whereas UEI enhances the underlying modulus contrast into improved strain contrast. The results are corroborated with literature and also with clinical patient images. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Uncertainty in Integrated Assessment Scenarios

    SciTech Connect

    Mort Webster

    2005-10-17

    trends from a model for uncertainty projections. The probability distributions of these critical model drivers, and the resulting uncertainty in projections from a range of models, can provide the basis of future emission scenario set designs.

  9. Development of Vibrational Culture Model Mimicking Vocal Fold Tissues.

    PubMed

    Kim, Dongjoo; Lim, Jae-Yol; Kwon, Soonjo

    2016-10-01

    The vocal folds (VFs) are connective tissues with complex matrix structures that provide the required mechanical properties for voice generation. VF injury leads to changes in tissue structure and properties, resulting in reduced voice quality. However, injury-induced biochemical changes and repair in scarred VF tissues have not been well characterized to date. To treat scarred VFs, it is essential to understand how physiological characteristics of VFs tissue change in response to external perturbation. In this study, we designed a simple vibrational culture model to mimic vibratory microenvironments observed in vivo. This model consists of a flexible culture plate, three linear actuators, a stereo splitter, and a function generator. Human vocal fold fibroblast (hVFF) monolayers were established on the flexible membrane, to which normal phonatory vibrations were delivered from linear actuators and a function generator. The hVFF monolayers were exposed to the vibrational stresses at a frequency of 205 Hz for 2, 6, and 10 h with maximum displacement of 47.1 μm, followed by a 6 h rest. We then observed the changes in cell morphology, cell viability, and gene expression related to extracellular matrix components. In our dynamic culture device mimicking normal phonatory frequencies, cell proliferation increased and expression of hyaluronic acid synthase 2 was downregulated in response to vibrational stresses. The results presented herein will be useful for evaluating cellular responses following VF injuries in the presence or absence of vibrational stresses.

  10. Mimicking static anisotropic fluid spheres in general relativity

    NASA Astrophysics Data System (ADS)

    Boonserm, Petarpa; Ngampitipan, Tritos; Visser, Matt

    2016-11-01

    We argue that an arbitrary general relativistic static anisotropic fluid sphere, (static and spherically symmetric but with transverse pressure not equal to radial pressure), can nevertheless be successfully mimicked by suitable linear combinations of theoretically attractive and quite simple classical matter: a classical (charged) isotropic perfect fluid, a classical electromagnetic field and a classical (minimally coupled) scalar field. While the most general decomposition is not unique, a preferred minimal decomposition can be constructed that is unique. We show how the classical energy conditions for the anisotropic fluid sphere can be related to energy conditions for the isotropic perfect fluid, electromagnetic field, and scalar field components of the model. Furthermore, we show how this decomposition relates to the distribution of both electric charge density and scalar charge density throughout the model. The generalized TOV equation implies that the perfect fluid component in this model is automatically in internal equilibrium, with pressure forces, electric forces, and scalar forces balancing the gravitational pseudo-force. Consequently, we can build theoretically attractive matter models that can be used to mimic almost any static spherically symmetric spacetime.

  11. Orbital compressed air and petroleum injury mimicking necrotizing fasciitis.

    PubMed

    Mellington, Faye E; Bacon, Annette S; Abu-Bakra, Mohammed A J; Martinez-Devesa, Pablo; Norris, Jonathan H

    2014-09-01

    Orbital injury secondary to petroleum-based products is rare. We report the first case, to our knowledge, of a combined compressed air and chemical orbital injury, which mimicked necrotizing fasciitis. A 58-year-old man was repairing his motorcycle engine when a piston inadvertently fired, discharging compressed air and petroleum-based carburetor cleaner into his left eye. He developed surgical emphysema, skin necrosis, and a chemical cellulitis, causing an orbital compartment syndrome. He was treated initially with antibiotics and subsequently with intravenous steroid and orbital decompression surgery. There was almost complete recovery by 4 weeks postsurgery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Petroleum-based products can cause severe skin irritation and necrosis. Compressed air injury can cause surgical emphysema. When these two mechanisms of injury are combined, the resulting orbitopathy and skin necrosis can mimic necrotizing fasciitis and cause diagnostic confusion. A favorable outcome is achievable with aggressive timely management. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Toxicology Analysis of Tissue-Mimicking Phantom Made From Gelatin

    NASA Astrophysics Data System (ADS)

    Dolbashid, A. S.; Hamzah, N.; Zaman, W. S. W. K.; Mokhtar, M. S.

    2017-06-01

    Skin phantom mimics the biological skin tissues as it have the ability to respond to changes in its environment. The development of tissue-mimicking phantom could contributes towards the reduce usage of animal in cosmetics and pharmacokinetics. In this study, the skin phantoms made from gelatin were tested with four different commonly available cosmetic products to determine the toxicity of each substance. The four substances used were; mercury-based whitening face cream, carcinogenic liquid make-up foundation, paraben-based acne cleanser, and organic lip balm. Toxicity test were performed on all of the phantoms. For toxicity testing, topographical and electrophysiological changes of the phantoms were evaluated. The ability of each respective phantom to react with mild toxic substances and its electrical resistance were analysed in to determine the toxicity of all the phantom models. Four-electrode method along with custom made electrical impedance analyser was used to differentiate electrical resistance between intoxicated phantom and non-intoxicated phantom in this study. Electrical resistance values obtained from the phantom models were significantly higher than the control group. The result obtained suggests the phantom as a promising candidate to be used as alternative for toxicology testing in the future.

  13. Sellar and parasellar intravascular lymphoma mimicking pituitary apoplexy.

    PubMed

    Rizek, Philippe; Seitelbach, Maayan; Alturkustani, Murad; Leung, Andrew; Fraser, J Alexander

    2012-03-01

    Intravascular lymphoma (IVL) is a rare subtype of large-cell non-Hodgkin lymphoma, characterized by proliferation of lymphoma cells within the lumina of small vessels. There are no previously reported cases of IVL involving the pituitary gland presenting with neuro-ophthalmic findings. A 68-year-old female presented with headache, right third nerve palsy, and Horner syndrome. MRI showed a 1.4-cm sellar mass consistent with a pituitary macroadenoma. Two weeks later, despite treatment with dexamethasone, the patient developed complete bilateral ophthalmoplegia and ptosis. Repeat MRI showed invasion of the clivus and cavernous sinuses, and a transsphenoidal pituitary biopsy was undertaken. The preliminary histopathology was consistent with bland pituitary apoplexy, but subsequent examination of an incidentally biopsied nasal polyp revealed endovascular malignant lymphoid cells that, on further scrutiny, were also present in the pituitary tissue. The diagnosis of IVL was confirmed, and the patient had an excellent clinical and radiological response to cyclophosphamide, doxorubicin, vincristine, prednisolone, and rituximab (CHOP-R) chemotherapy. IVL may involve the pituitary gland, causing sellar mass effect, cavernous sinus infiltration, and pituitary ischemia, mimicking pituitary apoplexy with neuro-ophthalmic features. It can be effectively treated with CHOP-R chemotherapy.

  14. Auditory-motor entrainment in vocal mimicking species

    PubMed Central

    2010-01-01

    We have recently found robust evidence of motor entrainment to auditory stimuli in multiple species of non-human animal, all of which were capable of vocal mimicry. In contrast, the ability remained markedly absent in many closely related species incapable of vocal mimicry. This suggests that vocal mimicry may be a necessary precondition for entrainment. However, within the vocal mimicking species, entrainment appeared non-randomly, suggesting that other components besides vocal mimicry play a role in the capacity and tendency to entrain. Here we discuss potential additional factors involved in entrainment. New survey data show that both male and female parrots are able to entrain, and that the entrainment capacity appears throughout the lifespan. We suggest routes for future study of entrainment, including both developmental studies in species known to entrain and further work to detect entrainment in species not well represented in our dataset. These studies may shed light on additional factors necessary for entrainment in addition to vocal mimicry. PMID:20714417

  15. Adenomatoid odontogenic tumour mimicking a periapical cyst in pregnant woman.

    PubMed

    Bhandari, Neha; Kothari, Mohit

    2010-06-01

    Adenomatoid odontogenic tumours (AOT) are uncommon odontogenic lesions characterized histologi-cally by duct-like structures derived from the epithelial component of the lesion and can be distinctly classified into follicular, extrafollicular and extraosseous variants (Neville BW, Damm DD, Allen CM, et al. Adenomatoid Odontogenic Tumor. A Text Book for Oral and Maxillofacial Pathology, 2(nd) edition, 621-3). Most of these tumours develop in the second or third decade of life and have a distinct predilection for women. The follicular variant accounts for 75% of reported cases (Curran AE, Miller EJ, Murrah VA. Adenomatoid odontogenic tumor presenting as periapical disease. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997;84:557-60) and is associated with the crown of an impacted tooth, commonly the maxillary canine. We present a rare case of extrafollicular AOT mimicking a periapical cyst that originated in a woman in her first trimester of pregnancy and enlarged rapidly thereafter. The lesion was enucleated and sent for histopathology and immunohistochemistry, which revealed AOT with a cystic component with no dependence on oestrogen or progestrone for its growth. This case of AOT introduces us to the unique variation in its presentation and the difficulty in differentiation from periapical disease of inflammatory origin. Copyright © 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

  16. Red blood cell-mimicking synthetic biomaterial particles.

    PubMed

    Doshi, Nishit; Zahr, Alisar S; Bhaskar, Srijanani; Lahann, Joerg; Mitragotri, Samir

    2009-12-22

    Biomaterials form the basis of current and future biomedical technologies. They are routinely used to design therapeutic carriers, such as nanoparticles, for applications in drug delivery. Current strategies for synthesizing drug delivery carriers are based either on discovery of materials or development of fabrication methods. While synthetic carriers have brought upon numerous advances in drug delivery, they fail to match the sophistication exhibited by innate biological entities. In particular, red blood cells (RBCs), the most ubiquitous cell type in the human blood, constitute highly specialized entities with unique shape, size, mechanical flexibility, and material composition, all of which are optimized for extraordinary biological performance. Inspired by this natural example, we synthesized particles that mimic the key structural and functional features of RBCs. Similar to their natural counterparts, RBC-mimicking particles described here possess the ability to carry oxygen and flow through capillaries smaller than their own diameter. Further, they can also encapsulate drugs and imaging agents. These particles provide a paradigm for the design of drug delivery and imaging carriers, because they combine the functionality of natural RBCs with the broad applicability and versatility of synthetic drug delivery particles.

  17. Solitary spinal dural syphilis granuloma mimicking a spinal meningioma.

    PubMed

    Zhou, Heng-Jun; Zhan, Ren-Ya; Chen, Man-Tao; Cao, Fei; Zheng, Xiu-Jue

    2014-01-01

    Dural granuloma is extremely rare. To our knowledge, there has no case reported solitary spinal dural syphilis granuloma worldwide so far. Here we report our findings in a 49-year-old woman, who presented with 10-year progressive left lower-limb numbness and two weeks of right lower-limb numbness. Magnetic resonance imaging (MRI) suggested a homogeneous enhanced spindle-shaped lesion, 2.9 × 1.5 cm in size, occupying the spinal intradural extramedullary space, at the level of Thoracic (T)-2/3, which mimicked the appearance of spinal meningioma. The Treponema pallidum particle agglutination (TPPA) test titer of 1:8, and the venereal diseases research laboratory of cerebral spinal fluid (VDRL-CSF) was reactive, so confirmed neurosyphilis was considered. After formal anti-syphilis treatment, posterior laminectomy surgery was performed, and the lesion was completely separated and extirpated. Final histopathologic diagnosis of the lesion was confirmed as chronic granulomatous inflammation, combined with the neurosyphilis history, spinal dural syphilis granuloma was finally diagnosed. Postoperatively, the patient recovered without any further treatment.

  18. Tophaceous gout of the lumbar spine mimicking a spinal meningioma.

    PubMed

    Ribeiro da Cunha, Pedro; Peliz, António Judice; Barbosa, Marcos

    2016-11-05

    Although gout is a common metabolic disorder, it usually affects distal joints of the appendicular skeleton. Axial spine involvement is rare, with only 131 cases reported in the literature. The authors report a rare case of lumbar spinal gout mimicking a spinal meningioma. A 77-year-old man with a history of gout presented with chronic low back pain and progressive paraparesis. Imaging revealed a lumbar spine compressive mass lesion with a dural tail signal. The differential diagnosis was thought to be straightforward favoring a spinal meningioma. Tophaceous gout was never considered. The presence of a dural tail associated with the lesion is an interesting detail of this case, that strongly misguided it and to the best of our knowledge it is the first one reported in the literature. The patient underwent surgery and intra-operative findings were surprisingly different from those expected, revealing a chalky white mass lesion firmly adherent and compressing the dural sac. It was completely excised, leaving the dura intact. Histopathology confirmed the diagnosis of tophaceous gout. The patient was sent to physical therapy and had a complete remission of pain and neurological deficit, regaining his walking capacity. Although spinal gout is rare, it should be considered in the differential diagnosis for patients presenting with symptoms of spinal stenosis, a suspicion of neoplastic lesion of the spine, and a previous history of gout. Early diagnosis can ensure proper and timely medical management, perhaps avoiding neurological compromise and the need for surgery.

  19. Mimicking Oxygen delivery and waste removal functions of blood.

    PubMed

    Zhang, Huaifa; Barralet, Jake E

    2017-02-15

    In addition to immunological and wound healing cell and platelet delivery, ion stasis and nutrient supply, blood delivers oxygen to cells and tissues and removes metabolic wastes. For decades researchers have been trying to develop approaches that mimic these two immediately vital functions of blood. Oxygen is crucial for the long-term survival of tissues and cells in vertebrates. Hypoxia (oxygen deficiency) and even at times anoxia (absence of oxygen) can occur during organ preservation, organ and cell transplantation, wound healing, in tumors and engineering of tissues. Different approaches have been developed to deliver oxygen to tissues and cells, including hyperbaric oxygen therapy (HBOT), normobaric hyperoxia therapy (NBOT), using biochemical reactions and electrolysis, employing liquids with high oxygen solubility, administering hemoglobin, myoglobin and red blood cells (RBCs), introducing oxygen-generating agents, using oxygen-carrying microparticles, persufflation, and peritoneal oxygenation. Metabolic waste accumulation is another issue in biological systems when blood flow is insufficient. Metabolic wastes change the microenvironment of cells and tissues, influence the metabolic activities of cells, and ultimately cause cell death. This review examines advances in blood mimicking systems in the field of biomedical engineering in terms of oxygen delivery and metabolic waste removal.

  20. Mimicking the magnetic properties of rare earth elements using superatoms

    PubMed Central

    Cheng, Shi-Bo; Berkdemir, Cuneyt; Castleman, A. W.

    2015-01-01

    Rare earth elements (REs) consist of a very important group in the periodic table that is vital to many modern technologies. The mining process, however, is extremely damaging to the environment, making them low yield and very expensive. Therefore, mimicking the properties of REs in a superatom framework is especially valuable but at the same time, technically challenging and requiring advanced concepts about manipulating properties of atom/molecular complexes. Herein, by using photoelectron imaging spectroscopy, we provide original idea and direct experimental evidence that chosen boron-doped clusters could mimic the magnetic characteristics of REs. Specifically, the neutral LaB and NdB clusters are found to have similar unpaired electrons and magnetic moments as their isovalent REs (namely Nd and Eu, respectively), opening up the great possibility in accomplishing rare earth mimicry. Extension of the superatom concept into the rare earth group not only further shows the power and advance of this concept but also, will stimulate more efforts to explore new superatomic clusters to mimic the chemistry of these heavy atoms, which will be of great importance in designing novel building blocks in the application of cluster-assembled nanomaterials. Additionally, based on these experimental findings, a novel “magic boron” counting rule is proposed to estimate the numbers of unpaired electrons in diatomic LnB clusters. PMID:25848014

  1. Acoustic resolution photoacoustic Doppler velocimetry in blood-mimicking fluids

    PubMed Central

    Brunker, Joanna; Beard, Paul

    2016-01-01

    Photoacoustic Doppler velocimetry provides a major opportunity to overcome limitations of existing blood flow measuring methods. By enabling measurements with high spatial resolution several millimetres deep in tissue, it could probe microvascular blood flow abnormalities characteristic of many different diseases. Although previous work has demonstrated feasibility in solid phantoms, measurements in blood have proved significantly more challenging. This difficulty is commonly attributed to the requirement that the absorber spatial distribution is heterogeneous relative to the minimum detectable acoustic wavelength. By undertaking a rigorous study using blood-mimicking fluid suspensions of 3 μm absorbing microspheres, it was discovered that the perceived heterogeneity is not only limited by the intrinsic detector bandwidth; in addition, bandlimiting due to spatial averaging within the detector field-of-view also reduces perceived heterogeneity and compromises velocity measurement accuracy. These detrimental effects were found to be mitigated by high-pass filtering to select photoacoustic signal components associated with high heterogeneity. Measurement under-reading due to limited light penetration into the flow vessel was also observed. Accurate average velocity measurements were recovered using “range-gating”, which furthermore maps the cross-sectional velocity profile. These insights may help pave the way to deep-tissue non-invasive mapping of microvascular blood flow using photoacoustic methods. PMID:26892989

  2. Hematological Changes Mimicking Myelodysplastic Syndrome Following Treatment for Osteosarcoma.

    PubMed

    Løhmann, Ditte J A; Hasle, Henrik

    2015-04-01

    Therapy-related myelodysplastic syndrome/acute myeloid leukemia (t-MDS/AML) is a feared long-term complication of pediatric cancer. Few osteosarcoma patients develop t-MDS/AML, but the frequency of hematological abnormalities after therapy is unknown. We reviewed biochemistry from osteosarcoma patients up to 3 years posttreatment. All children diagnosed with osteosarcoma at our department from 2006 to 2012 without relapse 1 month posttherapy were included (n=14). Serial blood counts posttherapy were analyzed. The median increase of mean corpuscular volume (MCV) from baseline was 8 fL 6 months posttherapy and remained >5 throughout follow-up. All posttreatment levels of MCV were above 90 fL in 5 patients. Six months posttherapy, the median difference for platelets, white blood count, and absolute neutrophil count had decreased from baseline. They remained under baseline throughout follow-up. Hemoglobin remained stable. Ferritin level was associated with increased MCV. MDS with monosomy 7 was diagnosed in 1 patient. Hypoplastic refractory cytopenia was found in another patient showing spontaneous normalization of hematologic values. More than a third of patients treated for osteosarcoma developed hematological abnormalities mimicking early MDS, but only 1 developed t-MDS/AML. Close hematological monitoring of patients recovering from osteosarcoma is essential and it is worth noting that hematological abnormalities are frequent and may be transitory.

  3. Postictal spectroscopy and imaging findings mimicking brain tumor recurrence.

    PubMed

    Hattingen, Elke; Franz, Kea; Pilatus, Ulrich; Weidauer, Stefan; Lanfermann, Heiner

    2006-07-01

    (1)H magnetic resonance spectroscopic imaging (MRSI) was performed on a patient with an admission diagnosis of recurrent astrocytoma. The patient had undergone surgical resection and radiation therapy for a left occipital astrocytoma WHO grade III 12 years previously, and presented with aphasia, right-sided hemiparesis, and severe headache. Postcontrast T1-weighted images showed cortical enhancement of the left parietotemporal lobe near the post-resection cavity. MRSI revealed a marked increase of trimethylamines (TMA), elevated creatine/creatinephosphate (tCr), and reduced N-acetyl-aspartate (tNAA) in the same brain region. The spectroscopic data were consistent with tumor recurrence. However, the pattern of contrast enhancement on magnetic resonance imaging (MRI), evidence of an epileptic focus on electroencephalography (EEG), and spontaneous regression of the symptoms argued against tumor recurrence. In a 4-week follow-up, the contrast enhancement disappeared on MRI and the EEG abnormalities and neurological symptoms resolved. Follow-up spectroscopic data showed a decrease in TMA compared to normal values. The tCr signal remained elevated but returned to normal values after 5 months. In conclusion, postictal neurological deficits with a temporary increase in TMA and tCr were diagnosed. This is the first report of seizure-induced MRS abnormalities mimicking tumor recurrence. (c) 2006 Wiley-Liss, Inc.

  4. Development and characterization of a brain tumor mimicking fluorescence phantom

    NASA Astrophysics Data System (ADS)

    Haj-Hosseini, Neda; Kistler, Benjamin; Wârdell, Karin

    2014-03-01

    Fluorescence guidance using 5-aminolevulinic acid (5-ALA) for brain tumor resection is a recent technique applied to the highly malignant brain tumors. Five-ALA accumulates as protoporphyrin IX fluorophore in the tumor cells in different concentrations depending on the tumor environment and cell properties. Our group has developed a fluorescence spectroscopy system used with a hand-held probe intra-operatively. The system has shown improvement of fluorescence detection and allows quantification that preliminarily correlates with tumor malignancy grade during surgery. However, quantification of fluorescence is affected by several factors including the initial fluorophore concentration, photobleaching due to operating lamps and attenuation from the blood. Accordingly, an optical phantom was developed to enable controlled fluorescence measurements and evaluation of the system outside of the surgical procedure. The phantom mimicked the optical properties of glioma at the specific fluorescence excitation wavelength when different concentrations of the fluorophore were included in the phantom. To allow evaluation of photobleaching, kinetics of fluorophore molecules in the phantom was restricted by solidifying the phantoms. Moreover, a model for tissue autofluorescence was added. The fluorescence intensity's correlation with fluorophore concentration in addition to the photobleaching properties were investigated in the phantoms and were compared to the clinical data measured on the brain tumor.

  5. Idiopathic Transverse Myelitis Mimicking an Intramedullary Spinal Cord Tumor

    PubMed Central

    Fanous, Andrew A.; Olszewski, Nathan P.; Lipinski, Lindsay J.; Qiu, Jingxin

    2016-01-01

    The differential diagnoses for spinal cord lesions include spinal tumors and inflammatory processes. The distinction between these pathologies can be difficult if solely based on imaging. We report for the first time to our knowledge a case of idiopathic transverse myelitis (ITM) mimicking a discrete cervical spinal lesion in a 66-year-old man who presented with gait instability and neck pain. The patient's symptoms failed to resolve after an initial course of steroid therapy. Surgical biopsy confirmed the diagnosis of ITM. Subsequent treatment with dexamethasone resulted in complete resolution of the symptoms as well as the intramedullary enhancement. ITM is most common in the cervical and thoracic spine, spanning 3-4 spinal segments. It usually occupies more than 50% of the cross-sectional area of the spinal cord and tends to be central, uniform, and symmetric. It exhibits patchy and peripheral contrast enhancement. These criteria are useful guidelines that help distinguish ITM from neoplastic spinal lesions. A decision to perform biopsy must take into consideration the patient's clinical symptoms, the rate of progression of neurological deficits, and the imaging characteristics of the lesion. Surgical biopsy for questionable lesions should be reserved for patients with progressive neurological deficits refractory to empirical medical therapy. PMID:27672469

  6. Mimicking Neural Stem Cell Niche by Biocompatible Substrates

    PubMed Central

    Regalado-Santiago, Citlalli; Juárez-Aguilar, Enrique; Olivares-Hernández, Juan David; Tamariz, Elisa

    2016-01-01

    Neural stem cells (NSCs) participate in the maintenance, repair, and regeneration of the central nervous system. During development, the primary NSCs are distributed along the ventricular zone of the neural tube, while, in adults, NSCs are mainly restricted to the subependymal layer of the subventricular zone of the lateral ventricles and the subgranular zone of the dentate gyrus in the hippocampus. The circumscribed areas where the NSCs are located contain the secreted proteins and extracellular matrix components that conform their niche. The interplay among the niche elements and NSCs determines the balance between stemness and differentiation, quiescence, and proliferation. The understanding of niche characteristics and how they regulate NSCs activity is critical to building in vitro models that include the relevant components of the in vivo niche and to developing neuroregenerative approaches that consider the extracellular environment of NSCs. This review aims to examine both the current knowledge on neurogenic niche and how it is being used to develop biocompatible substrates for the in vitro and in vivo mimicking of extracellular NSCs conditions. PMID:26880934

  7. Hypoxia-Mimicking Nanofibrous Scaffolds Promote Endogenous Bone Regeneration.

    PubMed

    Yao, Qingqing; Liu, Yangxi; Tao, Jianning; Baumgarten, Keith M; Sun, Hongli

    2016-11-30

    Utilizing biomimetic materials to potentiate endogenous cell growth or signaling is superior to relying on exogenous cells or signals for bone formation. Desferoxamine (DFO), which is a hypoxia-mimetic agent that chelates iron (Fe(3+)), mimics hypoxia to encourage bone healing. However, high cytotoxicity, off-target effects, and the short half-life of DFO have significantly impeded its further applications. We mitigated these side effects by locally immobilizing DFO onto a gelatin nanofibrous (GF) scaffold that retained DFO's ability to chelate Fe(3+). Moreover, DFO-functionalized GF (GF-DFO) scaffolds, which have similar micro/macrostructures to GF scaffolds, not only demonstrated decreased cytotoxicity on both human umbilical vein endothelial cells and human mesenchymal stem cells but also significantly increased vascular endothelial growth factor (VEGF) expression in vitro. Most importantly, in our in vivo experiments on a critical-sized cranial bone defect mouse model, a significant amount of bone was formed in most of the GF-DFO scaffolds after six weeks, while very little new bone was observed in the GF scaffolds. These data suggest that use of a hypoxia-mimicking nanofibrous scaffold is a promising strategy for promoting endogenous bone formation.

  8. Gorham's disease of the mandible mimicking periodontal disease on radiograph.

    PubMed

    Mignogna, Michele Davide; Fedele, Stefano; Lo Russo, Lucio; Lanza, Alessandro; Marenzi, Gaetano; Sammartino, Gilberto

    2005-09-01

    Gorham's disease is a rare disorder characterized by spontaneous and progressive osteolysis of one or more skeletal bones. The radiographic findings associated with Gorham's disease are particularly dramatic, as in some cases a complete resorption of the involved bone can occur, leading to the definition of phantom bone, vanishing bone, or disappearing bone disease. A 24-year-old female patient with a previous diagnosis of periodontal disease and progressive mandibular alveolar bone loss was referred to our Oral Medicine section. The initial radiographic picture showed infrabony defects and horizontal bone loss. After further extensive local and systemic evaluation, including histopathological, laboratory and imagine techniques investigations, the patient was diagnosed to be affected by Gorham's disease. Meanwhile the progression of the osteolytic process had caused the loosening of all the left mandibular teeth and a pathologic fracture. Appropriate medical therapy was successful in stabilizating the resorptive process, with no evidence of further progressive disease. When Gorham's disease involves the mandible, the role of the periodontologist is extremely important in diagnosing promptly the disorder and preventing the functional and aesthetic consequences of advanced and extensive bone loss. Gorham's disease should be included among the pathologic entities mimicking periodontal disease on radiograph, such as inflammatory disease (e.g. osteomyelitis), endocrine disease (e.g. hyperparathyroidism), intra-osseous malignancies or metastases, lymphoma, histiocytosis X, mainly eosinophilic granuloma, infective process (e.g. tuberculosis and actinomycosis), odontogenic tumours.

  9. Modulated Fluorophore Signal Recovery Buried within Tissue Mimicking Phantoms

    PubMed Central

    Sarkar, Saugata; Fan, Chaoyang; Hsiang, Jung-Cheng; Dickson, Robert M.

    2013-01-01

    Optically modulated fluorescence from ~140nM Cy5 is visualized when embedded up to 6 mm within skin tissue-mimicking phantoms, even in the presence of overwhelming background fluorescence and scatter. Experimental and finite element analysis (FEA)-based computational models yield excellent agreement in signal levels and predict biocompatible temperature changes. Using Synchronously Amplified Fluorescence Image Recovery (SAFIRe), dual laser excitation (primary laser: λ = 594nm, 0.29 kW/cm2; secondary laser: λ = 710nm, 5.9 kW/cm2, intensity-modulated at 100Hz) simultaneously excites fluorescence, and dynamically optically reverses the dark state buildup of primary laser-excited Cy5 molecules. As the modulated secondary laser both directly modulates Cy5 emission and is of lower energy than the collected Cy5 fluorescence, modulated Cy5 fluorescence in phantoms is free of obscuring background emission. The modulated fluorescence emission due to the secondary laser was recovered by Fourier transformation, yielding a specific and unique signature of the introduced fluorophores, with largely background-free detection, at excitation intensities close to the maximum permissible exposure (MPE) for skin. Experimental and computational models agree to within 8%, validating the computational model. As modulated fluorescence depends on the presence of both lasers, depth information as a function of focal position is also readily obtained from recovered modulated signal strength. PMID:23692258

  10. Wernicke's Encephalopathy Mimicking Acute Onset Stroke Diagnosed by CT Perfusion

    PubMed Central

    Advani, Rajiv; Kurz, Kathinka D.; Kurz, Martin W.

    2014-01-01

    Background. Metabolic syndromes such as Wernicke's encephalopathy may present with a sudden neurological deficit, thus mimicking acute onset stroke. Due to current emphasis on rapid admission and treatment of acute stroke patients, there is a significant risk that these stroke mimics may end up being treated with thrombolysis. Rigorous clinical and radiological skills are necessary to correctly identify such metabolic stroke mimics, in order to avoid doing any harm to these patients due to the unnecessary use of thrombolysis. Patient. A 51-year-old Caucasian male was admitted to our hospital with suspicion of an acute stroke due to sudden onset dysarthria and unilateral facial nerve paresis. Clinical examination revealed confusion and dysconjugate gaze. Computed tomography (CT) including a CT perfusion (CTP) scan revealed bilateral thalamic hyperperfusion. The use of both clinical and radiological findings led to correctly diagnosing Wernicke's encephalopathy. Conclusion. The application of CTP as a standard diagnostic tool in acute stroke patients can improve the detection of stroke mimics caused by metabolic syndromes as shown in our case report. PMID:24716022

  11. Multimodal 3D cancer-mimicking optical phantom

    PubMed Central

    Smith, Gennifer T.; Lurie, Kristen L.; Zlatev, Dimitar V.; Liao, Joseph C.; Ellerbee Bowden, Audrey K.

    2016-01-01

    Three-dimensional (3D) organ-mimicking phantoms provide realistic imaging environments for testing various aspects of optical systems, including for evaluating new probe designs, characterizing the diagnostic potential of new technologies, and assessing novel image processing algorithms prior to validation in real tissue. We introduce and characterize the use of a new material, Dragon Skin (Smooth-On Inc.), and fabrication technique, air-brushing, for fabrication of a 3D phantom that mimics the appearance of a real organ under multiple imaging modalities. We demonstrate the utility of the material and technique by fabricating the first 3D, hollow bladder phantom with realistic normal and multi-stage pathology features suitable for endoscopic detection using the gold standard imaging technique, white light cystoscopy (WLC), as well as the complementary imaging modalities of optical coherence tomography and blue light cystoscopy, which are aimed at improving the sensitivity and specificity of WLC to bladder cancer detection. The flexibility of the material and technique used for phantom construction allowed for the representation of a wide range of diseased tissue states, ranging from inflammation (benign) to high-grade cancerous lesions. Such phantoms can serve as important tools for trainee education and evaluation of new endoscopic instrumentation. PMID:26977369

  12. Acoustic resolution photoacoustic Doppler velocimetry in blood-mimicking fluids

    NASA Astrophysics Data System (ADS)

    Brunker, Joanna; Beard, Paul

    2016-02-01

    Photoacoustic Doppler velocimetry provides a major opportunity to overcome limitations of existing blood flow measuring methods. By enabling measurements with high spatial resolution several millimetres deep in tissue, it could probe microvascular blood flow abnormalities characteristic of many different diseases. Although previous work has demonstrated feasibility in solid phantoms, measurements in blood have proved significantly more challenging. This difficulty is commonly attributed to the requirement that the absorber spatial distribution is heterogeneous relative to the minimum detectable acoustic wavelength. By undertaking a rigorous study using blood-mimicking fluid suspensions of 3 μm absorbing microspheres, it was discovered that the perceived heterogeneity is not only limited by the intrinsic detector bandwidth; in addition, bandlimiting due to spatial averaging within the detector field-of-view also reduces perceived heterogeneity and compromises velocity measurement accuracy. These detrimental effects were found to be mitigated by high-pass filtering to select photoacoustic signal components associated with high heterogeneity. Measurement under-reading due to limited light penetration into the flow vessel was also observed. Accurate average velocity measurements were recovered using “range-gating”, which furthermore maps the cross-sectional velocity profile. These insights may help pave the way to deep-tissue non-invasive mapping of microvascular blood flow using photoacoustic methods.

  13. Acoustic resolution photoacoustic Doppler velocimetry in blood-mimicking fluids.

    PubMed

    Brunker, Joanna; Beard, Paul

    2016-02-19

    Photoacoustic Doppler velocimetry provides a major opportunity to overcome limitations of existing blood flow measuring methods. By enabling measurements with high spatial resolution several millimetres deep in tissue, it could probe microvascular blood flow abnormalities characteristic of many different diseases. Although previous work has demonstrated feasibility in solid phantoms, measurements in blood have proved significantly more challenging. This difficulty is commonly attributed to the requirement that the absorber spatial distribution is heterogeneous relative to the minimum detectable acoustic wavelength. By undertaking a rigorous study using blood-mimicking fluid suspensions of 3 μm absorbing microspheres, it was discovered that the perceived heterogeneity is not only limited by the intrinsic detector bandwidth; in addition, bandlimiting due to spatial averaging within the detector field-of-view also reduces perceived heterogeneity and compromises velocity measurement accuracy. These detrimental effects were found to be mitigated by high-pass filtering to select photoacoustic signal components associated with high heterogeneity. Measurement under-reading due to limited light penetration into the flow vessel was also observed. Accurate average velocity measurements were recovered using "range-gating", which furthermore maps the cross-sectional velocity profile. These insights may help pave the way to deep-tissue non-invasive mapping of microvascular blood flow using photoacoustic methods.

  14. Moderately nonlinear ultrasound propagation in blood-mimicking fluid.

    PubMed

    Kharin, Nikolay A; Vince, D Geoffrey

    2004-04-01

    In medical diagnostic ultrasound (US), higher than-in-water nonlinearity of body fluids and tissue usually does not produce strong nonlinearly distorted waves because of the high absorption. The relative influence of absorption and nonlinearity can be characterized by the Gol'dberg number Gamma. There are two limiting cases in nonlinear acoustics: weak waves (Gamma < 1) or strong waves (Gamma > 1). However, at diagnostic frequencies in tissue and body fluids, the nonlinear effects and effects of absorption more likely are comparable (Gol'dberg number Gamma approximately 1). The aim of this work was to study the nonlinear propagation of a moderately nonlinear US second harmonic signal in a blood-mimicking fluid. Quasilinear solutions to the KZK equation are presented, assuming radiation from a flat and geometrically focused circular Gaussian source. The solutions are expressed in a new simplified closed form and are in very good agreement with those of previous studies measuring and modeling Gaussian beams. The solutions also show good agreement with the measurements of the beams produced by commercially available transducers, even without special Gaussian shading.

  15. Biotinidase deficiency mimicking neuromyelitis optica: Initially exhibiting symptoms in adulthood.

    PubMed

    Bottin, Laure; Prud'hon, Sabine; Guey, Stéphanie; Giannesini, Claire; Wolf, Barry; Pindolia, Kirit; Stankoff, Bruno

    2015-10-01

    Children with untreated biotinidase deficiency can experience variable symptoms depending on their age of presentation. Older children and adolescents can exhibit predominant neurological deficits including para- or tetraparesis and vision loss. We report the first case of delayed-onset biotinidase deficiency in a young adult. A 22-year-old man presented with a disabling extensive myelopathy and bilateral optic neuropathy which mimicked the findings of a (seronegative) neuromyelitis optica. Imaging investigations were characterized by an MRI T2 hyper-intensity involving the spinal cord, the optic nerves, the fornix and the mammillar bodies, together with an increased (18)F-FDG uptake on positron emission tomography. He was ultimately shown to have profound biotinidase deficiency due to a novel missense mutation and was partly improved by oral biotin therapy. This individual exemplifies the need to include biotinidase deficiency in the differential diagnosis of patients with extensive myelopathy and/or bilateral optic neuropathy and argues for newborn screening for the disorder. © The Author(s), 2015.

  16. Riboswitch Structure: an Internal Residue Mimicking the Purine Ligand

    SciTech Connect

    Delfosse, V.; Bouchard, P; Bonneau, E; Dagenais, P; Lemay, J; Lafontaine, D; Legault, P

    2009-01-01

    The adenine and guanine riboswitches regulate gene expression in response to their purine ligand. X-ray structures of the aptamer moiety of these riboswitches are characterized by a compact fold in which the ligand forms a Watson-Crick base pair with residue 65. Phylogenetic analyses revealed a strict restriction at position 39 of the aptamer that prevents the G39-C65 and A39-U65 combinations, and mutational studies indicate that aptamers with these sequence combinations are impaired for ligand binding. In order to investigate the rationale for sequence conservation at residue 39, structural characterization of the U65C mutant from Bacillus subtilis pbuE adenine riboswitch aptamer was undertaken. NMR spectroscopy and X-ray crystallography studies demonstrate that the U65C mutant adopts a compact ligand-free structure, in which G39 occupies the ligand-binding site of purine riboswitch aptamers. These studies present a remarkable example of a mutant RNA aptamer that adopts a native-like fold by means of ligand mimicking and explain why this mutant is impaired for ligand binding. Furthermore, this work provides a specific insight into how the natural sequence has evolved through selection of nucleotide identities that contribute to formation of the ligand-bound state, but ensures that the ligand-free state remains in an active conformation.

  17. Synchrony and motor mimicking in chimpanzee observational learning

    PubMed Central

    Fuhrmann, Delia; Ravignani, Andrea; Marshall-Pescini, Sarah; Whiten, Andrew

    2014-01-01

    Cumulative tool-based culture underwrote our species' evolutionary success, and tool-based nut-cracking is one of the strongest candidates for cultural transmission in our closest relatives, chimpanzees. However the social learning processes that may explain both the similarities and differences between the species remain unclear. A previous study of nut-cracking by initially naïve chimpanzees suggested that a learning chimpanzee holding no hammer nevertheless replicated hammering actions it witnessed. This observation has potentially important implications for the nature of the social learning processes and underlying motor coding involved. In the present study, model and observer actions were quantified frame-by-frame and analysed with stringent statistical methods, demonstrating synchrony between the observer's and model's movements, cross-correlation of these movements above chance level and a unidirectional transmission process from model to observer. These results provide the first quantitative evidence for motor mimicking underlain by motor coding in apes, with implications for mirror neuron function. PMID:24923651

  18. Modulated Fluorophore Signal Recovery Buried within Tissue Mimicking Phantoms

    NASA Astrophysics Data System (ADS)

    Sarkar, Saugata; Fan, Chaoyang; Hsiang, Jung-Cheng; Dickson, Robert M.

    2013-10-01

    Optically modulated fluorescence from -140 nM Cy5 is visualized when embedded up to 6 mm within skin tissue mimicking phantoms, even in the presence of overwhelming background fluorescence and scatter. Experimental and finite element analysis (FEA)-based computational models yield excellent agreement in signal levels and predict biocompatible temperature changes. Using synchronously amplified fluorescence image recovery (SAFIRe), dual-laser excitation (primary laser: - = 594 nm, 0.29 kW/cm2; secondary laser: - = 710 nm, 5.9 kW/cm2, intensity-modulated at 100 Hz) simultaneously excites fluorescence and dynamically optically reverses the dark state buildup of primary laser-excited Cy5 molecules. As the modulated secondary laser both directly modulates Cy5 emission and is of lower energy than the collected Cy5 fluorescence, modulated Cy5 fluorescence in phantoms is free of obscuring background emission. The modulated fluorescence emission due to the secondary laser was recovered by Fourier transformation, yielding a specific and unique signature of the introduced fluorophores, with largely background-free detection, at excitation intensities close to the maximum permissible exposure (MPE) for skin. Experimental and computational models agree to within 8%, validating the computational model. As modulated fluorescence depends on the presence of both lasers, depth information as a function of focal position is also readily obtained from recovered modulated signal strength.

  19. Synchrony and motor mimicking in chimpanzee observational learning.

    PubMed

    Fuhrmann, Delia; Ravignani, Andrea; Marshall-Pescini, Sarah; Whiten, Andrew

    2014-06-13

    Cumulative tool-based culture underwrote our species' evolutionary success, and tool-based nut-cracking is one of the strongest candidates for cultural transmission in our closest relatives, chimpanzees. However the social learning processes that may explain both the similarities and differences between the species remain unclear. A previous study of nut-cracking by initially naïve chimpanzees suggested that a learning chimpanzee holding no hammer nevertheless replicated hammering actions it witnessed. This observation has potentially important implications for the nature of the social learning processes and underlying motor coding involved. In the present study, model and observer actions were quantified frame-by-frame and analysed with stringent statistical methods, demonstrating synchrony between the observer's and model's movements, cross-correlation of these movements above chance level and a unidirectional transmission process from model to observer. These results provide the first quantitative evidence for motor mimicking underlain by motor coding in apes, with implications for mirror neuron function.

  20. Trastuzumab-Induced Myocardiotoxicity Mimicking Acute Coronary Syndrome

    PubMed Central

    Ribeiro, K.B.; Miranda, C.H.; Andrade, J.M.; Galli, L.G.; Tiezzi, D.G.; Oliveira, H.F.; Zola, F.E.; Volpe, G.; Pazin-Filho, A.; Peria, F.M.

    2012-01-01

    Trastuzumab is an important biological agent in the treatment of HER2-positive breast cancer, with effects on response rates, progression-free survival, overall survival and quality of life. Although this drug is well tolerated in terms of adverse effects, trastuzumab-associated myocardiotoxicity has been described to have an incidence of 0.6–4.5% and in rare cases, the drug can trigger severe congestive heart failure with progression to death or even mimic acute coronary syndrome with complete left bundle branch blockade. In this paper is reported a case of trastuzumab-associated myocardiotoxicity manifesting as acute coronary syndrome in a 69-year-old female. The patient is currently undergoing a conservative clinical treatment that restricts overexertion. The majority of clinical studies report trastuzumab-induced cardiotoxicity as a rare event, and, when present, characterized by mild to moderate clinical signs, the ease of reversibility with pharmacological measures and the temporary discontinuation of the medication. Conversely, it is vital for the oncologist/cardiologist to consider the possibility that trastuzumab-induced cardiotoxicity may manifest itself as a severe clinical case, mimicking acute coronary syndrome, justifying careful risk stratification and adequate cardiac monitoring, especially in high-risk patients. PMID:22666200

  1. Extramedullary Plasmacytoma Mimicking Pancreatic Cancer: An Unusual Presentation

    PubMed Central

    Sciancalepore, Daniela; Musci, Sergio; Fracella, Maria Rosaria; D'Alesio, Grazia; Sportelli, Azzurra; Ingravallo, Giuseppe; Vacca, Angelo

    2016-01-01

    Multiple myeloma is a plasma cell tumor that homes to and expands in the bone marrow and that, despite the new available drugs, remains incurable. Extramedullary plasmacytoma is a not frequent manifestation during the natural history of multiple myeloma and is frequently associated with plasma cell bone marrow infiltration. The most common locations for an EMP include the gastrointestinal tract, pleura, testis, skin, peritoneum, liver, endocrine glands, and lymph nodes. Primary involvement of the gallbladder fossa is exceedingly rare. In this report, we describe a patient with multiple myeloma who achieved a clinical and serological remission after autologous transplant but progressed rapidly at extramedullary site mimicking a second cancer (i.e., pancreatic or biliary cancer). In this case, the extramedullary localization was refractory to standard therapy, differently from bone marrow localization, but responded to lymphoma-like therapy. In this patient (i) the particular site of developing plasmacytoma is the gallbladder fossa, (ii) the timing of onset of this neoplasm is immediately after autologous transplant, and (iii) its disjunction from primary myeloma is that it appears in clinical and serological remission phase which may be confounding during the diagnostic approach simulating a different tumor (solid tumor). PMID:27847663

  2. Preparation of artificial plasma membrane mimicking vesicles with lipid asymmetry.

    PubMed

    Lin, Qingqing; London, Erwin

    2014-01-01

    Lipid asymmetry, the difference in lipid distribution across the lipid bilayer, is one of the most important features of eukaryotic cellular membranes. However, commonly used model membrane vesicles cannot provide control of lipid distribution between inner and outer leaflets. We recently developed methods to prepare asymmetric model membrane vesicles, but facile incorporation of a highly controlled level of cholesterol was not possible. In this study, using hydroxypropyl-α-cyclodextrin based lipid exchange, a simple method was devised to prepare large unilamellar model membrane vesicles that closely resemble mammalian plasma membranes in terms of their lipid composition and asymmetry (sphingomyelin (SM) and/or phosphatidylcholine (PC) outside/phosphatidylethanolamine (PE) and phosphatidylserine (PS) inside), and in which cholesterol content can be readily varied between 0 and 50 mol%. We call these model membranes "artificial plasma membrane mimicking" ("PMm") vesicles. Asymmetry was confirmed by both chemical labeling and measurement of the amount of externally-exposed anionic lipid. These vesicles should be superior and more realistic model membranes for studies of lipid-lipid and lipid-protein interaction in a lipid environment that resembles that of mammalian plasma membranes.

  3. Mimicking the magnetic properties of rare earth elements using superatoms.

    PubMed

    Cheng, Shi-Bo; Berkdemir, Cuneyt; Castleman, A W

    2015-04-21

    Rare earth elements (REs) consist of a very important group in the periodic table that is vital to many modern technologies. The mining process, however, is extremely damaging to the environment, making them low yield and very expensive. Therefore, mimicking the properties of REs in a superatom framework is especially valuable but at the same time, technically challenging and requiring advanced concepts about manipulating properties of atom/molecular complexes. Herein, by using photoelectron imaging spectroscopy, we provide original idea and direct experimental evidence that chosen boron-doped clusters could mimic the magnetic characteristics of REs. Specifically, the neutral LaB and NdB clusters are found to have similar unpaired electrons and magnetic moments as their isovalent REs (namely Nd and Eu, respectively), opening up the great possibility in accomplishing rare earth mimicry. Extension of the superatom concept into the rare earth group not only further shows the power and advance of this concept but also, will stimulate more efforts to explore new superatomic clusters to mimic the chemistry of these heavy atoms, which will be of great importance in designing novel building blocks in the application of cluster-assembled nanomaterials. Additionally, based on these experimental findings, a novel "magic boron" counting rule is proposed to estimate the numbers of unpaired electrons in diatomic LnB clusters.

  4. Idiopathic hypertrophic pachymeningitis mimicking prolactinoma with recurrent vision loss.

    PubMed

    Lok, Julie Y C; Yip, Nelson K F; Chong, Kelvin K L; Li, C L; Young, Alvin L

    2015-08-01

    Idiopathic hypertrophic pachymeningitis is a rare inflammatory condition with diffuse thickening of the dura mater, which may cause a compressive effect or vascular compromise. We report on a 28-year-old Chinese woman with a history of granulomatous mastitis 7 years previously and oligomenorrhoea, headache, blurred vision, and raised prolactin level 2 years previously, that was diagnosed as prolactinoma and treated conservatively with bromocriptine. However, she had recurrent bilateral vision loss when the bromocriptine was stopped. Her symptoms were resolved by high-dose steroid injection but remained steroid-dependent. Serial magnetic resonance imaging scan showed progressive diffuse thickening of the pachymeningitis with disappearance of pituitary apoplexy. Lumbar puncture showed lymphocytosis with no organisms. Open biopsy of the meninges was performed and histology showed features of inflammatory infiltrates and vasculitis. This is an unusual presentation of a rare condition in this age-group, with co-existing granulomatous mastitis and chronic otitis media, and is a diagnostic challenge mimicking pituitary macroadenoma and meningioma in initial magnetic resonance imaging scans.

  5. Evaluation of tissue mimicking quality of tofu for biomedical ultrasound.

    PubMed

    Kim, Yong Tae; Kim, Ho Chul; Inada-Kim, Matthew; Jung, Sung Soo; Yun, Yong Hyeon; Jho, Moon Jae; Sandstrom, Kurt

    2009-03-01

    The tissue mimicking quality of tofu has been evaluated in terms of acoustic properties and acousto/thermal conversion as functions of frequency and diffraction corrected intensity over the 2 MHz to 18 MHz range using three unfocussed transducers with center frequencies of 5 MHz, 10 MHz and 15 MHz. The density and acoustic velocity were close to the American Institute of Ultrasound in Medicine (AIUM) recommended values for the soft tissue, however, the attenuation increases nonlinearly with frequency as alpha = 0.56 x f(1.3). As a result, the temperature rise in tofu due to ultrasound absorption is expressed by the product of the acousto/thermal conversion factor and the attenuation/diffraction corrected acoustic intensity. The decrease of temperature rise with depth measured by embedded thermocouples agrees with the theoretical exponential decrease of the attenuation/diffraction corrected acoustic intensity. The heat capacity per unit mass of tofu is 0.76 cal/g degrees C (equivalent to 3.18 J/g degrees C) of which about 76% is water. The nonlinear frequency dependence of attenuation in tofu as f(1.3) correctly describes the frequency dependence of temperature rise. The present results suggest that tofu may only be used in a limited low MHz range in view of the estimation of temperature rise and penetration depth due to nonlinear frequency dependence of attenuation.

  6. Modulated fluorophore signal recovery buried within tissue mimicking phantoms.

    PubMed

    Sarkar, Saugata; Fan, Chaoyang; Hsiang, Jung-Cheng; Dickson, Robert M

    2013-10-03

    Optically modulated fluorescence from ∼140 nM Cy5 is visualized when embedded up to 6 mm within skin tissue mimicking phantoms, even in the presence of overwhelming background fluorescence and scatter. Experimental and finite element analysis (FEA)-based computational models yield excellent agreement in signal levels and predict biocompatible temperature changes. Using synchronously amplified fluorescence image recovery (SAFIRe), dual-laser excitation (primary laser: λ = 594 nm, 0.29 kW/cm(2); secondary laser: λ = 710 nm, 5.9 kW/cm(2), intensity-modulated at 100 Hz) simultaneously excites fluorescence and dynamically optically reverses the dark state buildup of primary laser-excited Cy5 molecules. As the modulated secondary laser both directly modulates Cy5 emission and is of lower energy than the collected Cy5 fluorescence, modulated Cy5 fluorescence in phantoms is free of obscuring background emission. The modulated fluorescence emission due to the secondary laser was recovered by Fourier transformation, yielding a specific and unique signature of the introduced fluorophores, with largely background-free detection, at excitation intensities close to the maximum permissible exposure (MPE) for skin. Experimental and computational models agree to within 8%, validating the computational model. As modulated fluorescence depends on the presence of both lasers, depth information as a function of focal position is also readily obtained from recovered modulated signal strength.

  7. Angle-resolved spectroscopy: a tissue-mimicking phantom study

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Vasefi, Fartash; Chamson-Reig, Astrid; Najiminainia, Mohamadreza; Kaminska, Bozena; Carson, Jeffrey J. L.

    2012-03-01

    The Radial Angular Filter Array (RAFA) is a novel optical filter consisting of a radially-distributed series of micromachined channels with a focal length of a few millimeters. The RAFA filters photons passing through the focal point according to the propagation direction and has proven to be capable of collecting the angular distribution and the spectral information of photons simultaneously and non-invasively, which allows angle-resolved spectroscopic measurement of a turbid medium. To explore the feasibility of using this device to characterize the optical abnormalities in human tissues, we tested the performance of an angle-resolved RAFA-based spectroscopy system to detect absorption targets embedded within a tissue-mimicking phantom. The body of the phantom was made of 0.1% IntralipidTM/agarose gel (7 mm in thickness) and the targets were spherical (1.5 mm in radius) and contained 10 μM Indocyanine Green (ICG). The illumination source was a broadband near infrared (NIR) collimated beam. Photons were angularly filtered by the RAFA and spectrally resolved by a pushbroom spectrometer. The experimental results confirmed that the RAFA preferentially filtered photons that carried absorption and scattering information of the embedded targets.

  8. Pulmonary Actinomycosis Mimicking Pulmonary Aspergilloma and a Brief Review of the Literature

    PubMed Central

    Higashi, Yoshitsugu; Nakamura, Shigeki; Ashizawa, Nobuyuki; Oshima, Kazuhiro; Tanaka, Akitaka; Miyazaki, Taiga; Izumikawa, Koichi; Yanagihara, Katsunori; Yamamoto, Yoshihiro; Miyazaki, Yoshitsugu; Mukae, Hiroshi; Kohno, Shigeru

    2017-01-01

    Pulmonary actinomycosis is a rare pulmonary infection that often exhibits unspecific symptoms and radiological findings. We herein report a case of pulmonary actinomycosis that mimicked pulmonary aspergilloma in an immunocompetent patient. PMID:28202870

  9. Bronchogenic/foregut cyst of the ileal mesentery in a child mimicking ovarian mass.

    PubMed

    Markel, Troy A; Lin, Jingmei; Fan, Rong; Billmire, Deborah F

    2013-10-01

    Intraabdominal bronchogenic cysts, a type of foregut cyst, are very rare. We report a case in a 12-year-old female who presented with severe abdominal pain and, in radiology workup, a cystic lesion that mimicked ovarian mass.

  10. Scenarios and decisionmaking for complex environmental systems

    Treesearch

    Stephen R. Carpenter; Adena R. Rissman

    2012-01-01

    Scenarios are used for expanding the scope of imaginable outcomes considered by assessments, planning exercises, or research projects on social-ecological systems. We discuss a global case study, the Millennium Ecosystem Assessment, and a regional project for an urbanizing agricultural watershed. Qualitative and quantitative aspects of scenarios are complementary....

  11. Multimedia Scenario in a Primary School

    ERIC Educational Resources Information Center

    Nulden, Urban; Ward, Bodil

    2002-01-01

    Multimedia as an educational technology tool is used throughout the educational system. In this article we present a research project where multimedia scenario was used to initiate a discussion about Internet use among students and teachers at a primary school. Multimedia scenario is the use of large screen multimedia to initiate and facilitate…

  12. Scenario Planning at College of Marin.

    ERIC Educational Resources Information Center

    College of Marin, Kentfield, CA.

    This article reviews the scenario planning process implemented at the College of Marin (California). Scenario planning is a creative process in which a group of people who share a common fate develop stories about different ways their future might unfold, and use these stories to make decisions about what path to take. The Global Business Network…

  13. Molecular Diagnostic Analysis of Outbreak Scenarios

    ERIC Educational Resources Information Center

    Morsink, M. C.; Dekter, H. E.; Dirks-Mulder, A.; van Leeuwen, W. B.

    2012-01-01

    In the current laboratory assignment, technical aspects of the polymerase chain reaction (PCR) are integrated in the context of six different bacterial outbreak scenarios. The "Enterobacterial Repetitive Intergenic Consensus Sequence" (ERIC) PCR was used to analyze different outbreak scenarios. First, groups of 2-4 students determined optimal…

  14. Eight Scenarios for Work in the Future.

    ERIC Educational Resources Information Center

    Morf, Martin

    1983-01-01

    Changes in society and technology could bring a broad variety of possible futures, as these eight scenarios of the world of work show. The scenarios depict what we can expect if technology continues to progress and reduce the number of jobs available. Future work may be challenging and profitable. (NW)

  15. Architectures for Developing Multiuser, Immersive Learning Scenarios

    ERIC Educational Resources Information Center

    Nadolski, Rob J.; Hummel, Hans G. K.; Slootmaker, Aad; van der Vegt, Wim

    2012-01-01

    Multiuser immersive learning scenarios hold strong potential for lifelong learning as they can support the acquisition of higher order skills in an effective, efficient, and attractive way. Existing virtual worlds, game development platforms, and game engines only partly cater for the proliferation of such learning scenarios as they are often…

  16. Architectures for Developing Multiuser, Immersive Learning Scenarios

    ERIC Educational Resources Information Center

    Nadolski, Rob J.; Hummel, Hans G. K.; Slootmaker, Aad; van der Vegt, Wim

    2012-01-01

    Multiuser immersive learning scenarios hold strong potential for lifelong learning as they can support the acquisition of higher order skills in an effective, efficient, and attractive way. Existing virtual worlds, game development platforms, and game engines only partly cater for the proliferation of such learning scenarios as they are often…

  17. Molecular Diagnostic Analysis of Outbreak Scenarios

    ERIC Educational Resources Information Center

    Morsink, M. C.; Dekter, H. E.; Dirks-Mulder, A.; van Leeuwen, W. B.

    2012-01-01

    In the current laboratory assignment, technical aspects of the polymerase chain reaction (PCR) are integrated in the context of six different bacterial outbreak scenarios. The "Enterobacterial Repetitive Intergenic Consensus Sequence" (ERIC) PCR was used to analyze different outbreak scenarios. First, groups of 2-4 students determined optimal…

  18. Scenario Planning at College of Marin.

    ERIC Educational Resources Information Center

    College of Marin, Kentfield, CA.

    This article reviews the scenario planning process implemented at the College of Marin (California). Scenario planning is a creative process in which a group of people who share a common fate develop stories about different ways their future might unfold, and use these stories to make decisions about what path to take. The Global Business Network…

  19. Evaluation Framework for Dependable Mobile Learning Scenarios

    ERIC Educational Resources Information Center

    Bensassi, Manel; Laroussi, Mona

    2014-01-01

    The goal of the dependability analysis is to predict inconsistencies and to reveal ambiguities and incompleteness in the designed learning scenario. Evaluation, in traditional learning design, is generally planned after the execution of the scenario. In mobile learning, this stage becomes too difficult and expensive to apply due to the complexity…

  20. Writing clinical scenarios for clinical science questions.

    PubMed

    Smith, Phil Em; Mucklow, John C

    2016-04-01

    Written knowledge assessments for physicians in training typically involve multiple-choice questions that use a clinical scenario in a single-best-answer format. The Royal College of Physicians Part 1 MRCP(UK) examination includes basic sciences themes that are challenging to assess through a clinical scenario. A realistic clinical setting based on everyday clinical practice and integral to the question is the clearest demonstration that the knowledge being assessed is clinically relevant. However, without special attention to detail, the scenario in a clinical science question can appear redundant or artificial. Reading unnecessary material frustrates candidates and threatens the reputation of the assessment. In this paper we discuss why a clinical scenario is important for basic science questions and offer advice on setting realistic and plausible clinical scenarios for such questions.