Sample records for distributed vod based

  1. Multicast for savings in cache-based video distribution

    NASA Astrophysics Data System (ADS)

    Griwodz, Carsten; Zink, Michael; Liepert, Michael; On, Giwon; Steinmetz, Ralf

    1999-12-01

    Internet video-on-demand (VoD) today streams videos directly from server to clients, because re-distribution is not established yet. Intranet solutions exist but are typically managed centrally. Caching may overcome these management needs, however existing web caching strategies are not applicable because they work in different conditions. We propose movie distribution by means of caching, and study the feasibility from the service providers' point of view. We introduce the combination of our reliable multicast protocol LCRTP for caching hierarchies combined with our enhancement to the patching technique for bandwidth friendly True VoD, not depending on network resource guarantees.

  2. Interacting Effects of Leaf Water Potential and Biomass on Vegetation Optical Depth

    NASA Astrophysics Data System (ADS)

    Momen, M.; Wood, J. D.; Novick, K. A.; Pockman, W.; Konings, A. G.

    2017-12-01

    Remotely-sensed microwave observations of vegetation optical depth (VOD) have been widely used to examine vegetation responses to climate. Such studies have alternately found that VOD is sensitive to both biomass and canopy water content. However, the relative impacts of changes in phenology or water stress on VOD have not been disentangled. In particular, understanding whether leaf water potential (LWP) affects VOD may permit the assimilation of satellite observations into new large-scale plant hydraulic models. Despite extensive validation of the relationship between satellite-derived VOD estimates and vegetation density, relatively few studies have explicitly sought to validate the sensitivity of VOD to canopy water status, and none have studied the effect of variations in LWP on VOD. In this work, we test the sensitivity of VOD to variations in LWP, and present a conceptual framework which relates VOD to a combination of leaf water potential and total biomass including leaves, whose dynamics can be measured through leaf area index, and woody biomass. We used in-situ measurements of LWP data to validate the conceptual model in mixed deciduous forests in Indiana and Missouri, as well as a pinion-juniper woodland in New Mexico. Observed X-band VOD from the AMSR-E and AMSR2 satellites showed dynamics similar to those reconstructed VOD signals based on the new conceptual model which employs in-situ LWP data (R2=0.60-0.80). Because LWP data are not available at global scales, we further estimated ecosystem LWP based on remotely sensed surface soil moisture to better understand the sensitivity of VOD across ecosystems. At the global scale, incorporating a combination of biomass and water potential in the reconstructed VOD signal increased correlations with VOD about 15% compared to biomass alone and about 30% compared to water potential alone. In wetter regions with denser and taller canopy heights, VOD has a higher correlation with leaf area index than with water stress and vice versa in drier regions (see figure 1). Therefore, variations in both phenology and leaf water potential must be accounted for to accurately interpret the dynamics of VOD observations for ecological applications.

  3. Absence of VOD in paediatric thalassaemic HSCT recipients using defibrotide prophylaxis and intravenous Busulphan.

    PubMed

    Cappelli, Barbara; Chiesa, Robert; Evangelio, Costanza; Biffi, Alessandra; Roccia, Tito; Frugnoli, Ilaria; Biral, Erika; Noè, Anna; Fossati, Marco; Finizio, Valentina; Miniero, Roberto; Napolitano, Sara; Ferrua, Francesca; Soliman, Clara; Ciceri, Fabio; Roncarolo, Maria G; Marktel, Sarah

    2009-11-01

    Hepatic veno-occlusive disease (VOD) is a common complication of haematopoietic stem cell transplantation (HSCT), with reported incidences of 5-40% in children. Recently, defibrotide (DF) has been successfully used as prophylaxis and treatment of VOD. This study reports data on 63 human leucocyte antigen-matched HSCT performed in 57 children affected by beta thalassemia at very high risk for developing VOD (liver fibrosis, iron overload, hepatitis C virus infections, busulphan-based conditioning, methotraexate + ciclosporine). All patients received a busulphan-based conditioning regimen, either orally (four HSCT) or intravenously (59 HSCT). All patients received oral DF (40 mg/kg per day, final dose) as VOD prophylaxis from median day -9 to median day +29. In order to overcome the lack of oral paediatric formulations, a galenic formulation was administered. DF was well tolerated. Only one patient fulfilled Seattle Criteria for VOD diagnosis. This patient had discontinued DF 6 d prior to VOD onset, due to high risk of haemorrhage. We concluded that oral defibrotide prophylaxis and i.v. busulphan safely abated VOD incidence in high-risk patients who had undergone HSCT. A galenic preparation of oral DF also permits this treatment in low-weight patients. Costs of DF prophylaxis are acceptable considering the reduced incidence of VOD.

  4. Assessing the relationship between microwave vegetation optical depth and gross primary production

    NASA Astrophysics Data System (ADS)

    Teubner, Irene E.; Forkel, Matthias; Jung, Martin; Liu, Yi Y.; Miralles, Diego G.; Parinussa, Robert; van der Schalie, Robin; Vreugdenhil, Mariette; Schwalm, Christopher R.; Tramontana, Gianluca; Camps-Valls, Gustau; Dorigo, Wouter A.

    2018-03-01

    At the global scale, the uptake of atmospheric carbon dioxide by terrestrial ecosystems through photosynthesis is commonly estimated through vegetation indices or biophysical properties derived from optical remote sensing data. Microwave observations of vegetated areas are sensitive to different components of the vegetation layer than observations in the optical domain and may therefore provide complementary information on the vegetation state, which may be used in the estimation of Gross Primary Production (GPP). However, the relation between GPP and Vegetation Optical Depth (VOD), a biophysical quantity derived from microwave observations, is not yet known. This study aims to explore the relationship between VOD and GPP. VOD data were taken from different frequencies (L-, C-, and X-band) and from both active and passive microwave sensors, including the Advanced Scatterometer (ASCAT), the Soil Moisture Ocean Salinity (SMOS) mission, the Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) and a merged VOD data set from various passive microwave sensors. VOD data were compared against FLUXCOM GPP and Solar-Induced chlorophyll Fluorescence (SIF) from the Global Ozone Monitoring Experiment-2 (GOME-2). FLUXCOM GPP estimates are based on the upscaling of flux tower GPP observations using optical satellite data, while SIF observations present a measure of photosynthetic activity and are often used as a proxy for GPP. For relating VOD to GPP, three variables were analyzed: original VOD time series, temporal changes in VOD (ΔVOD), and positive changes in VOD (ΔVOD≥0). Results show widespread positive correlations between VOD and GPP with some negative correlations mainly occurring in dry and wet regions for active and passive VOD, respectively. Correlations between VOD and GPP were similar or higher than between VOD and SIF. When comparing the three variables for relating VOD to GPP, correlations with GPP were higher for the original VOD time series than for ΔVOD or ΔVOD≥0 in case of sparsely to moderately vegetated areas and evergreen forests, while the opposite was true for deciduous forests. Results suggest that original VOD time series should be used jointly with changes in VOD for the estimation of GPP across biomes, which may further benefit from combining active and passive VOD data.

  5. Cost-Effectiveness of Defibrotide in the Prophylaxis of Veno-Occlusive Disease after Pediatric Allogeneic Stem Cell Transplantation.

    PubMed

    Pichler, Herbert; Horner, Karolina; Engstler, Gernot; Poetschger, Ulrike; Glogova, Evgenia; Karlhuber, Susanne; Martin, Manuel; Eibler, Werner; Witt, Volker; Holter, Wolfgang; Matthes-Martin, Susanne

    2017-07-01

    Veno-occlusive disease (VOD) remains a serious complication after allogeneic hematopoietic stem cell transplantation (HSCT). Prophylactic use of defibrotide (DF) might further reduce VOD rates but has no impact on the incidence of severe VOD or VOD-associated mortality. We investigated the cost-effectiveness of prophylactic DF according to the British Committee for Standards in Haematology/British Society for Blood and Marrow Transplantation guidelines in 348 children who underwent transplantation between 2001 and 2014 in our hospital, 138 of whom were at risk for VOD. The VOD incidence was 7.4% for the total cohort. Patients at risk had a higher incidence of VOD compared with patients without risk factors (15.2% versus 2.4%, P < .0001). VOD occurred more often in patients after busulfan-based myeloablative conditioning than in patients after total body irradiation (11.2% versus 3.5%, P = .001). Donor types or the transplantation-related mortality (TRM) risk score did not correlate with VOD incidence. In 81% of patients who responded to therapeutic DF, VOD resolved completely. Overall VOD-associated mortality was .3% for the complete cohort, 3.7% for patients diagnosed with VOD, and 20% for patients with severe VOD. Neither the cumulative incidence of TRM (19% ± 8% versus 17% ± 2%, P = .706) nor the median length of hospitalization differed between patients with VOD and patients without. The median costs per HSCT in patients with VOD were about one-third higher than the overall median costs per transplantation at our institution. The calculated total costs of prophylactic DF treatment for 138 patients at risk was almost 6 times as high as the incremental costs for patients with VOD. We conclude that prophylactic DF for children at risk for VOD is not cost-effective with respect to TRM and length of hospital stay. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  6. Hepatic veno-occlusive disease in pediatric stem cell transplantation: impact of pre-emptive antithrombin III replacement and combined antithrombin III/defibrotide therapy.

    PubMed

    Haussmann, Ursula; Fischer, Joachim; Eber, Stefan; Scherer, Franziska; Seger, Reinhard; Gungor, Tayfun

    2006-06-01

    Hepatic veno-occlusive disease (VOD) remains a serious complication after hematopoietic stem cell transplantation (HSCT). Based on a protective effect of antithrombin III (ATIII) on endothelial cells, we assessed the incidence of VOD after pre-emptive ATIII replacement and the outcome of VOD after combined high dose defibrotide (DF) and ATIII therapy. This prospective case series comprised two phases. In the first phase 71 children did not receive any specific VOD prophylaxis or therapy (controls). In the second phase 91 children were given pre-emptive ATIII replacement in case of decreased ATIII activity (< or =70%). If VOD was diagnosed clinically (according to modified Seattle criteria), high dose defibrotide (60 mg/day) and ATIII replacement therapy were combined. The severity of VOD was determined according to the degree of multiple organ dysfunction. The incidence of VOD was similar in both groups (13/71, 18% vs. 14/91, 15%). All 14 patients in the second group who developed VOD showed decreased ATIII activity not more than 1 day prior to the clinical diagnosis of VOD. The resulting short duration of pre-emptive ATIII therapy failed to prevent VOD (OR 0.96). None of the patients (n=72) maintaining normal ATIII levels developed VOD. All 14 patients with VOD who received combined therapy achieved complete remission and 93 % (13/14) survived until day +100, compared to six survivors (46%) in the first group. Pre-emptive ATIII administration did not alter the incidence of VOD. Combination treatment with ATIII and defibrotide was safe and yielded excellent remission and survival rates.

  7. Exploiting the synergy between SMAP and SMOS to improve brightness temperature simulations and soil moisture retrievals in arid regions

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Mohsen; Alavipanah, Seyed Kazem; Hamzeh, Saeid; Amiraslani, Farshad; Neysani Samany, Najmeh; Wigneron, Jean-Pierre

    2018-02-01

    The objective of this study was to exploit the synergy between SMOS and SMAP based on vegetation optical depth (VOD) to improve brightness temperature (TB) simulations and land surface soil moisture (SM) retrievals in arid regions of the world. In the current operational algorithm of SMAP (level 2), vegetation water content (VWC) is considered as a proxy to compute VOD which is calculated by an empirical conversion function of NDVI. Avoiding the empirical estimation of VOD, the SMOS algorithm is used to retrieve simultaneously SM and VOD from TB observations. The present study attempted to improve SMAP TB simulations and SM retrievals by benefiting from the advantages of the SMOS (L-MEB) algorithm. This was achieved by using a synergy method based on replacing the default value of SMAP VOD with the retrieved value of VOD from the SMOS multi angular and bi-polarization observations of TB. The insitu SM measurements, used as reference SM in this study, were obtained from the International Soil Moisture Network (ISMN) over 180 stations located in arid regions of the world. Furthermore, four stations were randomly selected to analyze the temporal variations in VOD and SM. Results of the synergy method showed that the accuracy of the TB simulations and SM retrievals was respectively improved at 144 and 124 stations (out of a total of 180 stations) in terms of coefficient of determination (R2) and unbiased root mean squared error (UbRMSE). Analyzing the temporal variations in VOD showed that the SMOS VOD, conversely to the SMAP VOD, can better illustrate the presence of herbaceous plants and may be a better indicator of the seasonal changes in the vegetation density and biomass over the year.

  8. Estimating fire severity and carbon emissions over Australian tropical savannas based on passive microwave satellite observations

    NASA Astrophysics Data System (ADS)

    Chen, X.; Liu, Y.; Evans, J. P.; Parinussa, R.

    2017-12-01

    Carbon emissions from large-scale fire activity over the Australian tropical savannas have strong inter-annual variability, due mainly to variations in fuel accumulation in response to rainfall. We investigated the use of a recently developed satellite-based vegetation optical depth (VOD) dataset to estimate fire severity and carbon emission. VOD is sensitive to the dynamics of all aboveground vegetation and available nearly every two days. For areas burned during 2003 - 2010, we calculated the VOD change (ΔVOD) pre- and post-fire and the associated loss in above ground biomass carbon. Both results compare well with widely-accepted approaches: ΔVOD agreed well with the Normalized Burn Ratio change (ΔNBR) and carbon loss with modelled emissions from the Global Fire Emissions Database (GFED). We found that the ΔVOD and ΔNBR are generally linearly related. The Pearson correlation coefficients (R) between VOD- and GFED-based fire carbon emissions for monthly and annual total estimates are very high, 0.92 and 0.96 respectively. A key feature of fire carbon emissions is the strong inter-annual variation, ranging from 21.1 million tonnes in 2010 to 84.3 million tonnes in 2004. This study demonstrates that a reasonable estimate of fire carbon emissions can be achieved in a timely manner based on multiple satellite observations over the regions where the emissions are primarily from aboveground vegetation loss, which can be complementary to the currently used approaches.

  9. Late-onset hepatic veno-occlusive disease post autologous peripheral stem cell transplantation successfully treated with oral defibrotide.

    PubMed

    Shah, Mithun S; Jeevangi, Nandish Kumar S; Joshi, Amit; Khattry, Navin

    2009-01-01

    Hepatic veno-occlusive disease (VOD) remains one of the commonest and most serious complications after myeloablative hematopoietic stem cell transplantation (HSCT). Clinical diagnosis of hepatic VOD is based on the finding of the triad of painful hepatomegaly, hyperbilirubinemia, and unexplained fluid retention occurring within 21 days of the transplant. However, the uncommon clinical entity of late-onset VOD can occur even beyond 20 days and should be considered in the differential diagnosis of any liver disease of more than 3 weeks' duration. While mild cases usually resolve spontaneously, severe VOD is associated with a grim prognosis. Defibrotide, a polydisperse mixture of single-stranded oligonucleotide with antithrombotic and fibrinolytic effects on microvascular endothelium, has emerged as an effective and safe therapy for patients with severe VOD. We describe a patient who presented 55 days post transplant with clinical features suggestive of VOD. Upon treatment with oral defibrotide, he showed complete resolution of the VOD.

  10. Interacting Effects of Leaf Water Potential and Biomass on Vegetation Optical Depth: Effects of LWP and Biomass on VOD

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Momen, Mostafa; Wood, Jeffrey D.; Novick, Kimberly A.

    Remotely sensed microwave observations of vegetation optical depth (VOD) have been widely used for examining vegetation responses to climate. Nevertheless, the relative impacts of phenological changes in leaf biomass and water stress on VOD have not been explicitly disentangled. In particular, determining whether leaf water potential (ψL) affects VOD may allow these data sets as a constraint for plant hydraulic models. Here we test the sensitivity of VOD to variations in ψL and present a conceptual framework that relates VOD to ψL and total biomass including leaves, whose dynamics are measured through leaf area index, and woody components. We usedmore » measurements of ψL from three sites across the US—a mixed deciduous forests in Indiana and Missouri and a piñon-juniper woodland in New Mexico—to validate the conceptual model. The temporal dynamics of X-band VOD were similar to those of the VOD signal estimated from the new conceptual model with observed ψL (R2 = 0.6–0.8). At the global scale, accounting for a combination of biomass and estimated ψL (based on satellite surface soil moisture data) increased correlations with VOD by ~ 15% and 30% compared to biomass and water potential, respectively. In wetter regions with denser and taller canopy heights, VOD has a higher correlation with leaf area index than with water stress and vice versa in drier regions. Our results demonstrate that variations in both phenology and ψL must be considered to accurately interpret the dynamics of VOD observations for ecological applications.« less

  11. Interacting Effects of Leaf Water Potential and Biomass on Vegetation Optical Depth

    NASA Astrophysics Data System (ADS)

    Momen, Mostafa; Wood, Jeffrey D.; Novick, Kimberly A.; Pangle, Robert; Pockman, William T.; McDowell, Nate G.; Konings, Alexandra G.

    2017-11-01

    Remotely sensed microwave observations of vegetation optical depth (VOD) have been widely used for examining vegetation responses to climate. Nevertheless, the relative impacts of phenological changes in leaf biomass and water stress on VOD have not been explicitly disentangled. In particular, determining whether leaf water potential (ψL) affects VOD may allow these data sets as a constraint for plant hydraulic models. Here we test the sensitivity of VOD to variations in ψL and present a conceptual framework that relates VOD to ψL and total biomass including leaves, whose dynamics are measured through leaf area index, and woody components. We used measurements of ψL from three sites across the US—a mixed deciduous forests in Indiana and Missouri and a piñon-juniper woodland in New Mexico—to validate the conceptual model. The temporal dynamics of X-band VOD were similar to those of the VOD signal estimated from the new conceptual model with observed ψL (R2 = 0.6-0.8). At the global scale, accounting for a combination of biomass and estimated ψL (based on satellite surface soil moisture data) increased correlations with VOD by 15% and 30% compared to biomass and water potential, respectively. In wetter regions with denser and taller canopy heights, VOD has a higher correlation with leaf area index than with water stress and vice versa in drier regions. Our results demonstrate that variations in both phenology and ψL must be considered to accurately interpret the dynamics of VOD observations for ecological applications.

  12. Veno-occlusive disease/sinusoidal obstruction syndrome after haematopoietic stem cell transplantation: Middle East/North Africa regional consensus on prevention, diagnosis and management.

    PubMed

    Al Jefri, A H; Abujazar, H; Al-Ahmari, A; Al Rawas, A; Al Zahrani, Z; Alhejazi, A; Bekadja, M A; Ibrahim, A; Lahoucine, M; Ousia, S; Bazarbachi, A

    2017-04-01

    Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) of the liver is a serious, early complication of haematopoietic stem cell transplantation (HSCT), severe and very severe forms of which are associated with a high mortality rate. A wide variety of patient, disease and treatment-related risk factors for VOD/SOS have been identified. Several bodies have published recommendations for the diagnosis, prevention and management of VOD/SOS following HSCT. A group of regional experts have developed a consensus statement on the diagnosis, prevention and management of VOD/SOS in the Middle East and North Africa region to help in the management of HSCT patients in the region. Risk factors of particular relevance in the region include iron overload in thalassaemia patients, some hereditary metabolic disorders due to consanguinity and infection with hepatitis virus B or C. Recommendations include diagnosis of VOD/SOS based on established clinical criteria, prophylaxis with defibrotide and/or ursodeoxycholic acid in patients at increased risk of VOD/SOS, and treatment with defibrotide for patients with severe/very severe VOD/SOS (and, if clinically indicated, in those with moderate or rapidly progressing VOD/SOS, as per the new European Society for Blood and Marrow Transplantation classification).

  13. Hepatic veno-occlusive disease after hematopoietic stem cell transplantation: update on defibrotide and other current investigational therapies.

    PubMed

    Ho, V T; Revta, C; Richardson, P G

    2008-02-01

    Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), remains one of the most serious and common complications after myeloablative hematopoietic stem cell transplantation (HSCT). Clinical diagnosis of hepatic VOD is based on the clinical triad of (1) painful hepatomegaly, (2) hyperbilirubinemia and (3) unexplained fluid retention. While milder cases usually resolve spontaneously, severe VOD is associated with a grim prognosis. Defibrotide (DF), a polydisperse mixture of single-stranded oligonucleotide with antithrombotic and fibrinolytic effects on microvascular endothelium, has emerged as an effective and safe therapy for patients with severe VOD. Multiple studies, including a recent large international multicenter phase II clinical trial, have demonstrated 30-60% complete remission rates with DF, even among patients with severe VOD and multiorgan failure. This article will review our current understanding of hepatic VOD, and update the clinical trial experience with DF and other potential therapies for this feared transplant complication.

  14. The Relationship of Temporal Variations in SMAP Vegetation Optical Depth to Plant Hydraulic Behavior

    NASA Astrophysics Data System (ADS)

    Konings, A. G.

    2016-12-01

    The soil emissions measured by L-band radiometers such as that on the NASA Soil Moisture Active/Passive mission are modulated by vegetation cover as quantified by the soil scattering albedo and the vegetation optical depth (VOD). The VOD is linearly proportional to the total vegetation water content, which is dependent on both the biomass and relative water content of the plant. Biomass is expected to vary more slowly than water content. Variations in vegetation water content are highly informative as they are directly indicative of the degree of hydraulic stress (or lack thereof) experienced by the plant. However, robust retrievals are needed in order for SMAP VOD observations to be useful. This is complicated by the fact that multiple unknowns (soil moisture, VOD, and albedo) need to be determined from two highly correlated polarizations. This presentation will discuss the application to SMAP of a recently developed timeseries algorithm for VOD and albedo retrieval - the Multi-Temporal Dual Channel Algorithm MTDCA, and its interpretation for plant hydraulic applications. The MT-DCA is based on the assumption that, for consecutive overpasses at a given time of day, VOD varies more slowly than soil moisture. A two-overpass moving average can then be used to determine variations in VOD that are less sensitive to high-frequency noise than classical dual-channel algorithms. Seasonal variations of SMAP VOD are presented and compared to expected patterns based on rainfall and radiation seasonality. Taking advantage of the large diurnal variation (relative to the seasonal variation) of canopy water potention, diurnal variations (between 6AM and 6PM observations) of SMAP VOD are then used to calculate global variations in ecosystem-scale isohydricity - the degree of stomatal closure and xylem conductivity loss in response to water stress. Lastly, the effect of satellite sensing frequency and overpass time on water content across canopies of different height will be discussed.

  15. Development and Preliminary Psychometric Properties of an Instrument for the Measurement of Obsessional Dissociative Experiences: The Van Obsessional Dissociation Questionnaire (VOD-Q).

    PubMed

    Boysan, Murat; Yıldırım, Abdullah; Beşiroğlu, Lütfullah; Kefeli, Mehmet Celal; Kağan, Mücahit

    2018-01-04

    A growing body of research evidence documents the substantial associations between obsessive-compulsive disorder (OCD) and dissociation. This article describes the development and preliminary psychometric properties of the Van Obsessional Dissociation Questionnaire (VOD-Q). Obsessional dissociation is defined as a tendency to dissociate in reaction to distressing, unwanted and intrusive thoughts, images and impulses. The screening tool is conceptualized to tap obsessional dissociation across three dimensions: obsessional absorption, obsessional depersonalization/ derealization and obsessional amnesia. The VOD-Q, the Padua Inventory-Revised (PI-R), the Dissociative Experiences Scale (DES), and the Obsessive Belief Questionnaire (OBQ-44) were administered in this study. The results showed that the VOD-Q had excellent test-retest reliability (ranging from 0.73 to 0.90) and internal consistency (ranging from 0.90 to 0.97). The VOD-Q total and subscale scores were significantly associated with measures of obsessive-compulsive symptoms and dissociative experiences. OCD patients scored significantly higher on the VOD-Q than community participants. Based on the present findings, the VOD-Q appears to be a reliable and valid instrument for the measurement of obsessional dissociative experiences.

  16. Packet-aware transport for video distribution [Invited

    NASA Astrophysics Data System (ADS)

    Aguirre-Torres, Luis; Rosenfeld, Gady; Bruckman, Leon; O'Connor, Mannix

    2006-05-01

    We describe a solution based on resilient packet rings (RPR) for the distribution of broadcast video and video-on-demand (VoD) content over a packet-aware transport network. The proposed solution is based on our experience in the design and deployment of nationwide Triple Play networks and relies on technologies such as RPR, multiprotocol label switching (MPLS), and virtual private LAN service (VPLS) to provide the most efficient solution in terms of utilization, scalability, and availability.

  17. Evaluation of thromboelastometry parameters as predictive markers for sinusoidal obstruction syndrome in patients undergoing allogeneic stem cell transplantation for acute leukaemia

    PubMed Central

    Rupa-Matysek, Joanna; Gil, Lidia; Wojtasińska, Ewelina; Kanduła, Zuzanna; Nowicki, Adam; Matuszak, Magdalena; Komarnicki, Mieczysław

    2017-01-01

    Hepatic sinusoidal obstruction syndrome (previously named veno-occlusive disease, SOS/VOD) is a serious complication of allogeneic stem cell transplantation (HSCT). Early identification of patients at risk of SOS/VOD may possibly improve the outcome and reduce mortality. Rotation thromboelastometry (ROTEM) is global assay allowing for the precise assessment of both bleeding and thrombotic conditions, however, its usefulness in patients undergoing HSCT for acute leukaemia has not been studied. We evaluated the thromboelastometry parameters in patients undergoing allogeneic HSCT for acute leukaemia to identify candidate biomarkers of SOS/VOD occurrence. ROTEM assays (INTEM, EXTEM, FIBTEM, APTEM) were performed on day -10, on the day of stem cell infusion (day 0) and on days +12 and +28 post-HSCT. The diagnosis of SOS/VOD was based on the Baltimore criteria. Seven patients (26%) developed SOS/VOD. On day +12, the patients with SOS/VOD had statistically significant longer INTEM-CT (clotting time, 199 ± 33.41vs166 ± 23.65s, p = 0.0033), EXTEM-CT (69.5 ± 6.39vs.52 ± 3.42s, p = 0.0139) and FIBTEM-CT (69.5 ± 22.75vs. 50.8 ± 14.31s, p = 0.0124) compared to SOS/VOD (-). ROC curve on day +12 indicated a cut-off value of 179s in INTEM-CT (AUC = 0.91), 69s in EXTEM-CT (AUC = 0.90) and 102s in FIBTEM-CT (AUC = 0.82) for the prediction of SOS/VOD. This is the first study evaluating the usefulness of ROTEM assays in the early detection of haemostasis abnormalities predictive of SOS/VOD development in patients undergoing HSCT for acute leukemia. Patients with SOS/VOD had a significant delay in the initiation of thrombin formation in the analysed ROTEM assays. The utility of ROTEM assays in the optimal management of patients undergoing HSCT should be clarified in further prospective studies. PMID:28938703

  18. Manifestations and management of veno-occlusive disease/sinusoidal obstruction syndrome in the era of contemporary therapies.

    PubMed

    Tewari, Priti; Wallis, Whitney; Kebriaei, Partow

    2017-02-01

    The concept of veno-occlusive disease (VOD), along with our understanding of it, has historically been and remains an evolving phenomenon. This review presents a broad view of VOD, also known as sinusoidal obstruction syndrome (SOS), including (1) traditional hematopoietic stem cell transplant-associated VOD/SOS, (2) late-onset VOD/SOS, (3) pulmonary VOD, and (4) VOD/SOS associated with chemotherapy only. Several VOD/SOS management modalities exist that include modes for both prophylaxis and treatment. An extensive review of the literature on monoclonal antibodies, both approved and pending approval by the US Food and Drug Administration, reveals that only a few have been associated with an increased risk for VOD/SOS. In fact, bevacizumab appears to have a protective effect against the development of VOD/SOS. As the landscape of cancer treatment changes, careful attention needs to be focused on how new therapies affect the incidence of VOD/SOS.

  19. Disentangling the Virgo Overdensity with RR Lyrae stars

    NASA Astrophysics Data System (ADS)

    Vivas, A. Katherina; Zinn, Robert; Farmer, John; Duffau, Sonia; Ping, Yiding

    2016-11-01

    We use a combination of spatial distribution and radial velocity to search for halo substructures in a sample of 412 RR Lyrae stars (RRLSs) that covers a region of ∼525 square degrees of the Virgo overdensity (VOD) and spans distances from the Sun from 4 to 75 kpc. With a friends-of-friends algorithm we identified six high-significance groups of RRLSs in phase space, which we associate mainly with the VOD and with the Sagittarius stream. Four other groups were also flagged as less significant overdensities. Three high-significance and three lower-significance groups have distances between ∼10 and 20 kpc, which places them in the distance range attributed by others to the VOD. The largest of these is the Virgo stellar stream at 19 kpc, which has 18 RRLSs, a factor of two increase over the number known previously. While these VOD groups are distinct according to our selection criteria, their overlap in position and distance and, in a few cases, similarity in radial velocity are suggestive that they may not all stem from separate accretion events. Even so, the VOD appears to be caused by more than one overdensity. The Sagittarius (Sgr) stream is a very obvious feature in the background of the VOD at a mean distance of 44 kpc. Two additional high-significance groups were detected at distances \\gt 40 {kpc}. Their radial velocities and locations differ from the expected path of the Sgr debris in this part of the sky, and they are likely to be remnants of other accretion events.

  20. A distributed multichannel demand-adaptive P2P VoD system with optimized caching and neighbor-selection

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Chen, Minghua; Parekh, Abhay; Ramchandran, Kannan

    2011-09-01

    We design a distributed multi-channel P2P Video-on-Demand (VoD) system using "plug-and-play" helpers. Helpers are heterogenous "micro-servers" with limited storage, bandwidth and number of users they can serve simultaneously. Our proposed system has the following salient features: (1) it jointly optimizes over helper-user connection topology, video storage distribution and transmission bandwidth allocation; (2) it minimizes server load, and is adaptable to varying supply and demand patterns across multiple video channels irrespective of video popularity; and (3) it is fully distributed and requires little or no maintenance overhead. The combinatorial nature of the problem and the system demand for distributed algorithms makes the problem uniquely challenging. By utilizing Lagrangian decomposition and Markov chain approximation based arguments, we address this challenge by designing two distributed algorithms running in tandem: a primal-dual storage and bandwidth allocation algorithm and a "soft-worst-neighbor-choking" topology-building algorithm. Our scheme provably converges to a near-optimal solution, and is easy to implement in practice. Packet-level simulation results show that the proposed scheme achieves minimum sever load under highly heterogeneous combinations of supply and demand patterns, and is robust to system dynamics of user/helper churn, user/helper asynchrony, and random delays in the network.

  1. Late-Onset Hepatic Veno-Occlusive Disease after Allografting: Report of Two Cases with Atypical Clinical Features Successfully Treated with Defibrotide.

    PubMed

    Castellino, Alessia; Guidi, Stefano; Dellacasa, Chiara Maria; Gozzini, Antonella; Donnini, Irene; Nozzoli, Chiara; Manetta, Sara; Aydin, Semra; Giaccone, Luisa; Festuccia, Moreno; Brunello, Lucia; Maffini, Enrico; Bruno, Benedetto; David, Ezio; Busca, Alessandro

    2018-01-01

    Hepatic Veno-Occlusive Disease (VOD) is a potentially severe complication of hematopoietic stem cell transplantation (HSCT). Here we report two patients receiving an allogeneic HSCT who developed late onset VOD with atypical clinical features. The two patients presented with only few risk factors, namely, advanced acute leukemia, a myeloablative busulphan-containing regimen and received grafts from an unrelated donor. The first patient did not experience painful hepatomegaly and weight gain and both patients showed only a mild elevation in total serum bilirubin level. Most importantly, the two patients developed clinical signs beyond day 21 post-HSCT. Hepatic transjugular biopsy confirmed the diagnosis of VOD. Intravenous defibrotide was promptly started leading to a marked clinical improvement. Based on our experience, liver biopsy may represent a useful diagnostic tool when the clinical features of VOD are ambiguous. Early therapeutic intervention with defibrotide represents a crucial issue for the successful outcome of patients with VOD.

  2. Late-Onset Hepatic Veno-Occlusive Disease after Allografting: Report of Two Cases with Atypical Clinical Features Successfully Treated with Defibrotide

    PubMed Central

    Castellino, Alessia; Guidi, Stefano; Dellacasa, Chiara Maria; Gozzini, Antonella; Donnini, Irene; Nozzoli, Chiara; Manetta, Sara; Aydin, Semra; Giaccone, Luisa; Festuccia, Moreno; Brunello, Lucia; Maffini, Enrico; Bruno, Benedetto; David, Ezio; Busca, Alessandro

    2018-01-01

    Hepatic Veno-Occlusive Disease (VOD) is a potentially severe complication of hematopoietic stem cell transplantation (HSCT). Here we report two patients receiving an allogeneic HSCT who developed late onset VOD with atypical clinical features. The two patients presented with only few risk factors, namely, advanced acute leukemia, a myeloablative busulphan-containing regimen and received grafts from an unrelated donor. The first patient did not experience painful hepatomegaly and weight gain and both patients showed only a mild elevation in total serum bilirubin level. Most importantly, the two patients developed clinical signs beyond day 21 post-HSCT. Hepatic transjugular biopsy confirmed the diagnosis of VOD. Intravenous defibrotide was promptly started leading to a marked clinical improvement. Based on our experience, liver biopsy may represent a useful diagnostic tool when the clinical features of VOD are ambiguous. Early therapeutic intervention with defibrotide represents a crucial issue for the successful outcome of patients with VOD. PMID:29326798

  3. Global relation between microwave satellite vegetation products and vegetation productivity

    NASA Astrophysics Data System (ADS)

    Teubner, Irene E.; Forkel, Matthias; Jung, Martin; Miralles, Diego G.; Dorigo, Wouter A.

    2017-04-01

    The occurrence of unfavourable environmental conditions like droughts commonly reduces the photosynthetic activity of ecosystems and, hence, their potential to take up carbon from the atmosphere. Ecosystem photosynthetic activity is commonly determined using remote sensing observations in the optical domain, which however have limitations particularly in regions of frequent cloud cover, e.g. the tropics. In this study, we explore the potential of vegetation optical depth (VOD) from microwave satellite observations as an alternative source for assessing vegetation productivity. VOD serves as an estimate for vegetation density and water content, which has an impact on plant physiological processes and hence should potentially provide a link to gross primary production (GPP). However, to date, it is unclear how microwave-retrieved VOD data and GPP data are related. We compare seasonal dynamics and anomalies of VOD retrievals from different satellite sensors and microwave frequencies with site level and global GPP estimates. We use VOD observations from active (ASCAT) and passive microwave sensors (AMSR-E, SMOS). We include eddy covariance measurements from the FLUXNET2015 dataset to assess the VOD products at site level. For a global scale analysis, we use the solar-induced chlorophyll fluorescence (SIF) observations from GOME-2 as a proxy for GPP and the FLUXCOM GPP product, which presents an upscaling of site measurements based on remote sensing data. Our results demonstrate that in general a good agreement between VOD and GPP or SIF exists. However, the strength of these relations depends on the microwave frequency, land cover type, and the time within the growing season. Correlations between anomalies of VOD and GPP or SIF support the assumption that microwave-derived VOD can be used to monitor vegetation productivity dynamics. The study is performed as part of the EOWAVE project funded by the Vienna University of Technology (http://eowave.geo.tuwien.ac.at/) and the STR3S project funded by the Belgian Science Policy Office (BELSPO) as part of the STEREO III programme.

  4. Clinical predictors of vestibulo-ocular dysfunction in pediatric sports-related concussion.

    PubMed

    Ellis, Michael J; Cordingley, Dean M; Vis, Sara; Reimer, Karen M; Leiter, Jeff; Russell, Kelly

    2017-01-01

    OBJECTIVE There were 2 objectives of this study. The first objective was to identify clinical variables associated with vestibulo-ocular dysfunction (VOD) detected at initial consultation among pediatric patients with acute sports-related concussion (SRC) and postconcussion syndrome (PCS). The second objective was to reexamine the prevalence of VOD in this clinical cohort and evaluate the effect of VOD on length of recovery and the development of PCS. METHODS A retrospective review was conducted for all patients with acute SRC and PCS who were evaluated at a pediatric multidisciplinary concussion program from September 2013 to May 2015. Acute SRS was defined as presenting < 30 days postinjury, and PCS was defined according to the International Classification of Diseases, 10th Revision criteria and included being symptomatic 30 days or longer postinjury. The initial assessment included clinical history and physical examination performed by 1 neurosurgeon. Patients were assessed for VOD, defined as the presence of more than 1 subjective vestibular and oculomotor complaint (dizziness, diplopia, blurred vision, etc.) and more than 1 objective physical examination finding (abnormal near point of convergence, smooth pursuits, saccades, or vestibulo-ocular reflex testing). Poisson regression analysis was used to identify factors that increased the risk of VOD at initial presentation and the development of PCS. RESULTS Three hundred ninety-nine children, including 306 patients with acute SRC and 93 with PCS, were included. Of these patients, 30.1% of those with acute SRC (65.0% male, mean age 13.9 years) and 43.0% of those with PCS (41.9% male, mean age 15.4 years) met the criteria for VOD at initial consultation. Independent predictors of VOD at initial consultation included female sex, preinjury history of depression, posttraumatic amnesia, and presence of dizziness, blurred vision, or difficulty focusing at the time of injury. Independent predictors of PCS among patients with acute SRC included the presence of VOD at initial consultation, preinjury history of depression, and posttraumatic amnesia at the time of injury. CONCLUSIONS This study identified important potential risk factors for the development of VOD following pediatric SRC. These results provide confirmatory evidence that VOD at initial consultation is associated with prolonged recovery and is an independent predictor for the development of PCS. Future studies examining clinical prediction rules in pediatric concussion should include VOD. Additional research is needed to elucidate the natural history of VOD following SRC and establish evidence-based indications for targeted vestibular rehabilitation.

  5. Efficient data replication for the delivery of high-quality video content over P2P VoD advertising networks

    NASA Astrophysics Data System (ADS)

    Ho, Chien-Peng; Yu, Jen-Yu; Lee, Suh-Yin

    2011-12-01

    Recent advances in modern television systems have had profound consequences for the scalability, stability, and quality of transmitted digital data signals. This is of particular significance for peer-to-peer (P2P) video-on-demand (VoD) related platforms, faced with an immediate and growing demand for reliable service delivery. In response to demands for high-quality video, the key objectives in the construction of the proposed framework were user satisfaction with perceived video quality and the effective utilization of available resources on P2P VoD networks. This study developed a peer-based promoter to support online advertising in P2P VoD networks based on an estimation of video distortion prior to the replication of data stream chunks. The proposed technology enables the recovery of lost video using replicated stream chunks in real time. Load balance is achieved by adjusting the replication level of each candidate group according to the degree-of-distortion, thereby enabling a significant reduction in server load and increased scalability in the P2P VoD system. This approach also promotes the use of advertising as an efficient tool for commercial promotion. Results indicate that the proposed system efficiently satisfies the given fault tolerances.

  6. Stem cell transplantation in children with infantile osteopetrosis is associated with a high incidence of VOD, which could be prevented with defibrotide.

    PubMed

    Corbacioglu, S; Hönig, M; Lahr, G; Stöhr, S; Berry, G; Friedrich, W; Schulz, A S

    2006-10-01

    Malignant infantile osteopetrosis (MIOP) is a rare hereditary disorder of osteoclast function, which can be reversed by hematopoietic stem cell transplantation (SCT). We observed a high incidence of hepatic veno-occlusive disease (VOD) in transplanted patients and explored the prevention of this complication by using defibrotide (DF) as a prophylaxis. Twenty children with MIOP were consecutively transplanted in our center between 1996 and 2005. Eleven of these patients were transplanted between 1996 and 2001 and experienced an overall incidence of VOD of 63.6% (7/11). VOD was severe in three patients and one patient succumbed to VOD-related multi-organ failure. Owing to this very high incidence of VOD, DF prophylaxis was initiated in nine patients consecutively transplanted between 2001 and 2005. In this group, only one patient (11.1%) was diagnosed with moderate VOD. We report here a very high risk in patients with MIOP to develop VOD after transplantation. Prophylactic DF was implemented in our current transplant protocol and reduced the VOD rate significantly in this high-risk population.

  7. Low, fixed dose defibrotide in management of hepatic veno-occlusive disease post stem cell transplantation.

    PubMed

    Bagal, Bhausaheb; Chandrasekharan, Arun; Chougle, Aliya; Khattry, Navin

    2018-03-01

    Hepatic veno-occlusive disease (VOD) is well recognized potentially serious regimen-related toxicity seen after stem cell transplantation. Severe VOD is associated with poor long-term outcomes with very high mortality. Besides supportive care, only defibrotide has been found to be effective in the management of VOD. The recommended dose of defibrotide is 25mg/kg/d but there has been no classical dose finding study done for this drug. A higher dose of defibrotide is associated with increased risk of bleeding and this drug is prohibitively expensive. We report our experience of using fixed low dose of defibrotide in patients with VOD. We retrospectively evaluated 511 patients who underwent stem cell transplant at our center from November 2007 and December 2015. All patients received ursodeoxycholic acid as VOD prophylaxis. Modified Seattle criterion was used for diagnosis and severity grading of VOD. Patients developing VOD were initially treated with furosemide and adequate analgesia. Defibrotide was started within 12 to 24 hours of diagnosis of VOD. All adult patients received defibrotide at a fixed dose of 200mg twice daily while two children were given dose of 100mg and 50mg twice daily. Nine (1.7%) of our patients developed VOD. Daily dose of defibrotide ranged from 5mg/kg/d to 20mg/kg/d till resolution of VOD. All patients had complete resolution of VOD. None of our patients required ventilator support or dialysis. No episodes of bleeding were observed. No dose response relationship was observed between defibrotide dose and time to resolution of VOD. Low fixed dose defibrotide initiated early seems to be effective and safe in treatment of VOD. This is relevant in a resource limited setting and warrants prospective evaluation. Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

  8. Use of defibrotide in the treatment and prevention of veno-occlusive disease.

    PubMed

    Richardson, Paul; Linden, Erica; Revta, Carolyn; Ho, Vincent

    2009-08-01

    Hepatic veno-occlusive disease (VOD) is one of the most important complications of high-dose chemotherapy and stem cell transplantation. VOD is a clinical syndrome characterized by jaundice, hepatic enlargement and fluid retention typically seen by day +30 after transplantation. Severe VOD is complicated by multiorgan failure and a high mortality rate approaching 100%. Defibrotide (DF) is a novel agent with both antithrombotic and fibrinolytic properties that has emerged as an effective therapy for severe VOD. In Phase II studies, treatment of severe VOD has resulted in complete responses of 30-60% and survival past day 100 ranging between 32-50%. A Phase III, historically controlled study of DF for treatment of severe VOD has recently been completed and results are awaited with interest. In addition, DF may be effective prophylaxis for VOD in high-risk patients. This review will focus on a summary of the pharmacology of DF and the clinical evidence for its use in VOD.

  9. Changing Climate and Overgrazing Are Decimating Mongolian Steppes

    PubMed Central

    Liu, Yi Y.; Evans, Jason P.; McCabe, Matthew F.; de Jeu, Richard A. M.; van Dijk, Albert I. J. M.; Dolman, Albertus J.; Saizen, Izuru

    2013-01-01

    Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988–2008) record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass), to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation. PMID:23451249

  10. Changing climate and overgrazing are decimating Mongolian steppes.

    PubMed

    Liu, Yi Y; Evans, Jason P; McCabe, Matthew F; de Jeu, Richard A M; van Dijk, Albert I J M; Dolman, Albertus J; Saizen, Izuru

    2013-01-01

    Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988-2008) record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass), to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation.

  11. Veno-occlusive disease nurse management: development of a dynamic monitoring tool by the GITMO nursing group.

    PubMed

    Botti, Stefano; Orlando, Laura; Gargiulo, Gianpaolo; Cecco, Valentina De; Banfi, Marina; Duranti, Lorenzo; Samarani, Emanuela; Netti, Maria Giovanna; Deiana, Marco; Galuppini, Vera; Pignatelli, Adriana Concetta; Ceresoli, Rosanna; Vedovetto, Alessio; Rostagno, Elena; Bambaci, Marilena; Dellaversana, Cristina; Luminari, Stefano; Bonifazi, Francesca

    2016-01-01

    Veno-occlusive disease (VOD) is a complication arising from the toxicity of conditioning regimens that have a significant impact on the survival of patients who undergo stem cell transplantation. There are several known risk factors for developing VOD and their assessment before the start of conditioning regimens could improve the quality of care. Equally important are early identification of signs and symptoms ascribable to VOD, rapid diagnosis, and timely adjustment of support therapy and treatment. Nurses have a fundamental role at the stages of assessment and monitoring for signs and symptoms; therefore, they should have documented skills and training. The literature defines nurses' areas of competence in managing VOD, but in the actual clinical practice, this is not so clear. Moreover, there is an intrinsic difficulty in managing VOD due to its rapid and often dramatic evolution, together with a lack of care tools to guide nurses. Through a complex evidence-based process, the Gruppo Italiano per il Trapianto di Midollo Osseo (GITMO), cellule staminali emopoietiche e terapia cellulare nursing board has developed an operational flowchart and a dynamic monitoring tool applicable to haematopoietic stem cell transplantation patients, whether they develop this complication or not.

  12. Veno-occlusive disease nurse management: development of a dynamic monitoring tool by the GITMO nursing group

    PubMed Central

    Botti, Stefano; Orlando, Laura; Gargiulo, Gianpaolo; Cecco, Valentina De; Banfi, Marina; Duranti, Lorenzo; Samarani, Emanuela; Netti, Maria Giovanna; Deiana, Marco; Galuppini, Vera; Pignatelli, Adriana Concetta; Ceresoli, Rosanna; Vedovetto, Alessio; Rostagno, Elena; Bambaci, Marilena; Dellaversana, Cristina; Luminari, Stefano; Bonifazi, Francesca

    2016-01-01

    Veno-occlusive disease (VOD) is a complication arising from the toxicity of conditioning regimens that have a significant impact on the survival of patients who undergo stem cell transplantation. There are several known risk factors for developing VOD and their assessment before the start of conditioning regimens could improve the quality of care. Equally important are early identification of signs and symptoms ascribable to VOD, rapid diagnosis, and timely adjustment of support therapy and treatment. Nurses have a fundamental role at the stages of assessment and monitoring for signs and symptoms; therefore, they should have documented skills and training. The literature defines nurses’ areas of competence in managing VOD, but in the actual clinical practice, this is not so clear. Moreover, there is an intrinsic difficulty in managing VOD due to its rapid and often dramatic evolution, together with a lack of care tools to guide nurses. Through a complex evidence-based process, the Gruppo Italiano per il Trapianto di Midollo Osseo (GITMO), cellule staminali emopoietiche e terapia cellulare nursing board has developed an operational flowchart and a dynamic monitoring tool applicable to haematopoietic stem cell transplantation patients, whether they develop this complication or not. PMID:27594906

  13. Deformation of the total ozone content field in the tropical zone

    NASA Technical Reports Server (NTRS)

    Vasilyev, Victor I.

    1994-01-01

    Presented are the ozone investigation results obtained in the tropical zone. Measurements of the total ozone content (TOC) were carried out by the ozonometer M-124. The ozonometer was automated to investigate the ozone intradiurnal variations and to increase precision of the TOC measurements. Obtained results allowed us to follow the effect of tropical cyclones (TC) on the TOC field. Several days before the TC formation the TOC increase is observed in daily mean course compared with the background one. Three types of trend can be singled out in the TOC intradiurnal course: zero, parabolic, quasi-linear. Maximum velocities of a trend are observed some days before the TC formation. Analogous harmonic constituents are mainly presented as spectrum of daily means of ozone, mean and absolute velocities of trend and dispersion as well as spectra of meteorological, hydrometeorological and actinometric values. Revealed is a number of day-to-day ozone variations concerned with large-scale circulations; moisture content in the atmosphere. Obtained are the data about short-period ozone waves (period less than a day). Thin-film silver sensors were used to measure the vertical ozone distribution (VOD). Atmospheric aerosol and VOD measurements were carried out simultaneously, they gave data of the VOD layered structure, where the VOD local minima coincided with the position of aerosol layers' maxima.

  14. Earlier defibrotide initiation post-diagnosis of veno-occlusive disease/sinusoidal obstruction syndrome improves Day +100 survival following haematopoietic stem cell transplantation.

    PubMed

    Richardson, Paul G; Smith, Angela R; Triplett, Brandon M; Kernan, Nancy A; Grupp, Stephan A; Antin, Joseph H; Lehmann, Leslie; Miloslavsky, Maja; Hume, Robin; Hannah, Alison L; Nejadnik, Bijan; Soiffer, Robert J

    2017-07-01

    Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a progressive, potentially fatal complication of conditioning for haematopoietic stem cell transplant (HSCT). The VOD/SOS pathophysiological cascade involves endothelial-cell activation and damage, and a prothrombotic-hypofibrinolytic state. Severe VOD/SOS (typically characterized by multi-organ dysfunction) may be associated with >80% mortality. Defibrotide is approved for treating severe hepatic VOD/SOS post-HSCT in the European Union, and for hepatic VOD/SOS with renal or pulmonary dysfunction post-HSCT in the United States. Previously, defibrotide (25 mg/kg/day in 4 divided doses for a recommended ≥21 days) was available through an expanded-access treatment protocol for patients with VOD/SOS. Data from this study were examined post-hoc to determine if the timing of defibrotide initiation post-VOD/SOS diagnosis affected Day +100 survival post-HSCT. Among 573 patients, defibrotide was started on the day of VOD/SOS diagnosis in approximately 30%, and within 7 days in >90%. The relationship between Day +100 survival and treatment initiation before/after specific days post-diagnosis showed superior survival when treatment was initiated closer to VOD/SOS diagnosis with a statistically significant trend over time for better outcomes with earlier treatment initiation (P < 0·001). These results suggest that initiation of defibrotide should not be delayed after diagnosis of VOD/SOS. © 2017 The Authors. British Journal of Haematology published by John Wiley & Sons Ltd.

  15. Effects of changes in vertical occlusal dimension on heart rate fluctuations in guinea pigs.

    PubMed

    Taga, Hitoshi; Azuma, Yukio; Maehara, Kiyoshi; Nomura, Shuichi

    2012-01-01

    We have previously reported that the decrease of the vertical occlusal dimension (VOD) led to heart failure and abnormalities in creatine phosphokinase (CPK) in guinea pigs. In the present study, we investigated the autonomic activity and the origin of the abnormality in CPK under different occlusal conditions. Guinea pigs were separated into the following five groups: untreated control, reduced VOD, slit, restored VOD and increased VOD groups and compared for their electrocardiogram and heart rate fluctuations for two weeks using Fluclet, computer software. The control group revealed no changes in heart rate fluctuations or posture. The reduced VOD group exhibited a two-phase wave of heart rate fluctuations, with the first peak 0-2 days after teeth grinding, and the second peak starting from 4 days after teeth grinding until sudden death (usually 12th day), accompanied by head drop. The slit and the restored VOD groups exhibited only the first peak. The increased VOD group, with approximately 3 mm-thick acrylic pellets bonded to the posterior teeth, showed no heart rate fluctuations. Body weight loss was most prominent in the reduced VOD group, and became much milder in the order of increased VOD, restored and slit groups. The reduced VOD group exhibited transient elevation of skeletal muscle type of CPK isozyme activity within two days after treatment. The present study suggests that the first peak of heart rate fluctuations is caused by pulpal stimulation, and the second peak by excessive contraction (excessive excitation of the motor output system and the autonomic nervous system) of the masticatory muscles. On the other hand, increased VOD did not influence either the motor or the autonomic nervous system.

  16. High Variability in the Reported Management of Hepatic Veno-Occlusive Disease in Children after Hematopoietic Stem Cell Transplantation.

    PubMed

    Skeens, Micah A; McArthur, Jennifer; Cheifetz, Ira M; Duncan, Christine; Randolph, Adrienne G; Stanek, Joseph; Lehman, Leslie; Bajwa, Rajinder

    2016-10-01

    Veno-occlusive disease (VOD) is a potentially fatal complication of hematopoietic stem cell transplantation (HSCT). Patients with VOD are often critically ill and require close collaboration between transplant physicians and intensivists. We surveyed members of a consortium of pediatric intensive care unit (PICU) and transplant physicians to assess variability in the self-reported approach to the diagnosis and management of VOD. An internet-based self-administered survey was sent to pediatric HSCT and PICU providers from September 2014 to February 2015. The survey contained questions relating to the diagnosis and treatment of VOD. The response rate was 41% of 382 providers surveyed. We found significant variability in the diagnostic and management approaches to VOD in children. Even though ultrasound is not part of the diagnostic criteria, providers reported using reversal of portal venous flow seen on abdominal ultrasound in addition to Seattle criteria (70%) or Baltimore criteria to make the diagnosis of VOD. Almost 40% of respondents did not diagnose VOD in anicteric patients (bilirubin < 2 mg/dL). Most providers (75%) initiated treatment with defibrotide at the time of diagnosis, but 14%, 7%, and 6% of the providers waited for reversal of portal venous flow, renal dysfunction, or pulmonary dysfunction, respectively, to develop before initiating therapy. Only 50% of the providers restricted fluids to 75% of the daily maintenance, whereas 21% did not restrict fluids at all. Albumin with diuretics was used by 95% of respondents. Platelets counts were maintained at 20,000 to 50,000/mm(3) and 10,000 to 20,000/mm(3) by 64% and 20% of the respondents, respectively. Paracentesis was generally initiated in the setting of oliguria or hypoxia, and nearly 50% of the providers used continuous drainage to gravity, whereas the remainder used an intermittent drainage approach. Nearly 73% of the transplant providers used VOD prophylaxis, whereas the remainder did not use any medications for VOD prophylaxis. There was also considerable variation in the management strategies among the transplant and critical care providers. We conclude that there is considerable self-reported variability in the diagnosis and management of VOD in children. The practice variations reported in this study should encourage the development of standard practice guidelines, which will be helpful in improving the outcome of this potentially fatal complication. Copyright © 2016 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  17. Defibrotide for Treatment of Severe Veno-Occlusive Disease in Pediatrics and Adults: An Exploratory Analysis Using Data from the CIBMTR

    PubMed Central

    Strouse, Christopher; Richardson, Paul; Prentice, Grant; Korman, Sandra; Hume, Robin; Nejadnik, Bijan; Horowitz, Mary M.; Saber, Wael

    2016-01-01

    Veno-occlusive disease (VOD) is an early and serious complication of hematopoietic cell transplantation (HCT) that is associated with inferior survival, particularly when it is complicated by multi-organ failure (severe VOD). We evaluated the efficacy of defibrotide in the treatment of severe VOD using observational data from the Center for International Blood and Marrow Transplant Research (CIBMTR). Eight thousand three hundred forty-one patients treated by HCT between 2008 and 2011 were identified from the CIBMTR clinical database; 3.2% met criteria for VOD and 1.2% met criteria for severe VOD. Patients with a diagnosis of VOD as reported to the CIBMTR by their transplanting centers, who had no prior history of cirrhosis, and who had a maximum total bilirubin >2.0mg/dl by day +100 post-HCT were selected for study. Severe VOD was defined as VOD occurring in the setting of renal impairment requiring dialysis or any non-infectious pulmonary abnormality. Patients with severe VOD were divided into two groups for analysis: those treated with defibrotide (n=41) and those not treated with defibrotide (n=55). Patients in the non-defibrotide group were older, were more likely to be male, were more likely to have a history of previous fungal infection, and had a higher proportion of clinically significant pre-existing disease or organ impairment. Survival at day +100 was 39% (95% CI: 24.8–54.3%) in patients receiving defibrotide and 30.9% (95% CI: 19.5% – 43.6%) in those not receiving defibrotide. Resolution of VOD at day +100 was 51% in the defibrotide group, and 29% in the non-defibrotide group (difference 22.1%, 95% CI: 2.6% – 42%). The results of our study are consistent with previously reported experiences with defibrotide, confirm the poor outcome of this syndrome, and suggest defibrotide is effective in the treatment of severe VOD. PMID:27108694

  18. Consensus Report by Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees: Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents, Part 1: Focus on Investigations, Prophylaxis, and Specific Treatment.

    PubMed

    Bajwa, Rajinder P S; Mahadeo, Kris M; Taragin, Benjamin H; Dvorak, Christopher C; McArthur, Jennifer; Jeyapalan, Asumthia; Duncan, Christine N; Tamburro, Robert; Gehred, Alison; Lehmann, Leslie; Richardson, Paul; Auletta, Jeffery J; Woolfrey, Ann E

    2017-11-01

    Veno-occlusive disease (VOD) is a common and potentially fatal complication in children undergoing hematopoietic cell transplantation (HCT). It occurs in about one-third of all patients undergoing transplantation and is fatal in 50% of patients with severe disease. Early intervention and specific treatment with defibrotide are associated with improved outcomes. However, there is a lack of supportive care guidelines for management of the multiorgan dysfunction seen in most cases. There is high variability in the management of VOD, which may contribute to the increased morbidity and mortality. Although there is ample research in the specific treatment of VOD, there is paucity of literature regarding the management of ascites, transfusions requirements, fluids and electrolyte dysfunction, delirium, and investigations in children with VOD. The joint working committees of the Pediatric Acute Lung Injury and Sepsis Investigators and the Pediatric Blood and Marrow Transplantation Consortium collaborated to develop a series of evidence-based supportive care guidelines for management of VOD. The quality of evidence was rated and recommendations were made using Grading of Recommendations, Assessment, Development and Evaluation criteria. This manuscript is part 1 of the series and focuses on the need to develop these guidelines; methodology used to establish the guidelines; and investigations needed for diagnosis, prophylaxis, and treatment of VOD in children. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  19. Sinusoidal obstruction syndrome/veno-occlusive disease: current situation and perspectives—a position statement from the European Society for Blood and Marrow Transplantation (EBMT)

    PubMed Central

    Mohty, M; Malard, F; Abecassis, M; Aerts, E; Alaskar, A S; Aljurf, M; Arat, M; Bader, P; Baron, F; Bazarbachi, A; Blaise, D; Ciceri, F; Corbacioglu, S; Dalle, J-H; Duarte, R F; Fukuda, T; Huynh, A; Masszi, T; Michallet, M; Nagler, A; NiChonghaile, M; Pagluica, T; Peters, C; Petersen, F B; Richardson, P G; Ruutu, T; Savani, B N; Wallhult, E; Yakoub-Agha, I; Carreras, E

    2015-01-01

    Sinusoidal obstruction syndrome or veno-occlusive disease (SOS/VOD) is a potentially life-threatening complication of hematopoietic SCT (HSCT). This review aims to highlight, on behalf of the European Society for Blood and Marrow Transplantation, the current knowledge on SOS/VOD pathophysiology, risk factors, diagnosis and treatments. Our perspectives on SOS/VOD are (i) to accurately identify its risk factors; (ii) to define new criteria for its diagnosis; (iii) to search for SOS/VOD biomarkers and (iv) to propose prospective studies evaluating SOS/VOD prevention and treatment in adults and children. PMID:25798682

  20. Defibrotide for the treatment of sinusoidal obstruction syndrome: evaluation of response to therapy and patient outcomes.

    PubMed

    Coutsouvelis, John; Avery, Sharon; Dooley, Michael; Kirkpatrick, Carl; Spencer, Andrew

    2018-03-01

    Defibrotide is an agent used to treat sinusoidal obstruction syndrome (SOS/VOD) in patients undergoing haemopoietic stem cell transplantation. The aim of this study was to evaluate the effectiveness of defibrotide used within institutional guidelines for the treatment of SOS/VOD in patients undergoing haemopoietic stem cell transplantation (HSCT). Data for 23 patients was retrospectively reviewed to evaluate the effectiveness of defibrotide and the utility of response criteria to direct therapy as specified within institution guidelines. Patients met institutional criteria for a diagnosis of SOS/VOD based on predominantly Baltimore criteria and received defibrotide. Stabilisation or improvement in symptoms and biochemical markers was required for continuation of therapy with defibrotide. Overall, 14 patients responded to therapy. Survival at day 100 post HSCT was 70%. Median serum (total) bilirubin concentrations in all evaluable patients had decreased at days 5 and 10 (p < 0.001). There was a proportional reduction in median weight of 4% by day 5 and 6.6% by day 10 (p < 0.001). On cessation of defibrotide, there was a decrease in the proportion of patients exhibiting hepatomegaly (p = 0.02), ascites (p < 0.01) and requiring oxygen supplementation (p < 0.01), with 70% survival at day 100 post HSCT. Defibrotide to treat SOS/VOD and continued based on attainment of early response was effective management of this condition. Defibrotide should be considered in any consensus protocol providing guidance on the management of SOS/VOD, with future studies considered to assess appropriate time points for response to therapy during treatment.

  1. Defibrotide in the prevention and treatment of veno-occlusive disease in autologous and allogeneic stem cell transplantation in children.

    PubMed

    Qureshi, Amrana; Marshall, Lynley; Lancaster, Donna

    2008-04-01

    Hepatic veno-occlusive disease (VOD) is a common (10-50%) and serious complication of haematological stem cell transplantation (HSCT), with up to 90% mortality rates. We carried out a study to assess whether the use of prophylactic defibrotide in paediatric patients undergoing HSCT results in a lower frequency or severity of hepatic VOD. Forty-seven successive patients who underwent transplantation between April 2004 and December 2005 were given defibrotide prophylaxis and were compared with 56 historical controls transplanted between November 2001 and April 2004. No serious side effects were reported. High risk patients in the control group received ursodeoxycholic acid and tinzaparin as VOD prophylaxis. The groups were matched for sex, age, type of transplant and risk. In the defibrotide group, four patients developed clinical VOD (Seattle criteria) although two had liver biopsies which showed graft versus host disease (GvHD). Defibrotide dose was increased and symptoms resolved within 14 days. Of the control group four patients had VOD. Two of these patients had reversed hepatic vein flow and died 30 days post-transplant, partly due to VOD. VOD was associated with busulfan conditioning (P = 0.001) and not with age, sex, type of transplant, GvHD, abnormal liver function prior to transplant or type of antifungal prophylaxis. VOD incidence and severity was reduced in the defibrotide group which suggests that defibrotide might be effective in preventing and treating VOD. Sufficiently powered randomised trials are now required to definitively test the role of defibrotide in this setting. (c) 2008 Wiley-Liss, Inc.

  2. Global Scale Simultaneous Retrieval of Smoothened Vegetation Optical Depth and Surface Roughness Parameter using AMSR-E X-band Observations

    NASA Astrophysics Data System (ADS)

    Lanka, Karthikeyan; Pan, Ming; Konings, Alexandra; Piles, María; D, Nagesh Kumar; Wood, Eric

    2017-04-01

    Traditionally, passive microwave retrieval algorithms such as Land Parameter Retrieval Model (LPRM) estimate simultaneously soil moisture and Vegetation Optical Depth (VOD) using brightness temperature (Tb) data. The algorithm requires a surface roughness parameter which - despite implications - is generally assumed to be constant at global scale. Due to inherent noise in the satellite data and retrieval algorithm, the VOD retrievals are usually observed to be highly fluctuating at daily scale which may not occur in reality. Such noisy VOD retrievals along with spatially invariable roughness parameter may affect the quality of soil moisture retrievals. The current work aims to smoothen the VOD retrievals (with an assumption that VOD remains constant over a period of time) and simultaneously generate, for the first time, global surface roughness map using multiple descending X-band Tb observations of AMSR-E. The methodology utilizes Tb values under a moving-time-window-setup to estimate concurrently the soil moisture of each day and a constant VOD in the window. Prior to this step, surface roughness parameter is estimated using the complete time series of Tb record. Upon carrying out the necessary sensitivity analysis, the smoothened VOD along with soil moisture retrievals is generated for the 10-year duration of AMSR-E (2002-2011) with a 7-day moving window using the LPRM framework. The spatial patterns of resulted global VOD maps are in coherence with vegetation biomass and climate conditions. The VOD results also exhibit a smoothening effect in terms of lower values of standard deviation. This is also evident from time series comparison of VOD and LPRM VOD retrievals without optimization over moving windows at several grid locations across the globe. The global surface roughness map also exhibited spatial patterns that are strongly influenced by topography and land use conditions. Some of the noticeable features include high roughness over mountainous regions and heavily vegetated tropical rainforests, low roughness in desert areas and moderate roughness value over higher latitudes. The new datasets of VOD and surface roughness can help improving the quality of soil moisture retrievals. Also, the methodology proposed is generic by nature and can be implemented over currently operating AMSR2, SMOS, and SMAP soil moisture missions.

  3. Defibrotide for the prevention of hepatic veno-occlusive disease after hematopoietic stem cell transplantation: a systematic review.

    PubMed

    Zhang, Lifei; Wang, Yebo; Huang, He

    2012-01-01

    Prophylactic use of defibrotide (DF) to prevent veno-occlusive disease (VOD), a relatively common and high-risk complication of hematopoietic stem cell transplantation (HSCT), may be an encouraging modality to reduce morbidity and mortality from VOD. However, conclusions remain unclear. We carried out a systematic review to summarize the state of knowledge. One randomized controlled trial (RCT), four cohort studies and eight case series studies were found, including a total of 1230 patients. The overall mean incidence of VOD in patients using DF was 4.7% (95% CI, 3.3-6.1) which was significantly lower than the data 13.7% (95% CI, 13.3-14.1) across 135 studies using no VOD prophylaxis (p < 0.005). The meta-analysis of the incidence of VOD in controlled trials revealed a statistical reduction in VOD incidence in the DF group (RR = 0.47, 95% CI, 0.31-0.73). The overall mean incidence of severe VOD was 0.8% (95% CI, 0.2-1.4). The RR was 0.31 (95% CI, 0.09-1.06). However, the lack of RCTs and the methodological weaknesses of the studies may preclude making generalizable conclusions. Our review described that DF appears promising for VOD prevention and large RCT is needed for further confirmation. © 2012 John Wiley & Sons A/S.

  4. Defibrotide for Treatment of Severe Veno-Occlusive Disease in Pediatrics and Adults: An Exploratory Analysis Using Data from the Center for International Blood and Marrow Transplant Research.

    PubMed

    Strouse, Christopher; Richardson, Paul; Prentice, Grant; Korman, Sandra; Hume, Robin; Nejadnik, Bijan; Horowitz, Mary M; Saber, Wael

    2016-07-01

    Veno-occlusive disease (VOD) is an early and serious complication of hematopoietic cell transplantation (HCT) that is associated with inferior survival, particularly when it is complicated by multiorgan failure (severe VOD). We evaluated the efficacy of defibrotide in the treatment of severe VOD using observational data from the Center for International Blood and Marrow Transplant Research (CIBMTR). Eight thousand three hundred forty-one patients treated by HCT between 2008 and 2011 were identified from the CIBMTR clinical database; 3.2% met criteria for VOD and 1.2% met criteria for severe VOD. Patients with a diagnosis of VOD as reported to the CIBMTR by their transplanting centers, who had no prior history of cirrhosis, and who had a maximum total bilirubin level > 2.0 mg/dL by day +100 post-HCT were selected for study. Severe VOD was defined as VOD occurring in the setting of renal impairment requiring dialysis or any noninfectious pulmonary abnormality. Patients with severe VOD were divided into 2 groups for analysis: those treated with defibrotide (n = 41) and those not treated with defibrotide (n = 55). Patients in the nondefibrotide group were older, were more likely to be male, were more likely to have a history of previous fungal infection, and had a higher proportion of clinically significant pre-existing disease or organ impairment. Survival rate at day +100 was 39% (95% CI, 24.8% to 54.3%) in patients receiving defibrotide and 30.9% (95% CI, 19.5% to 43.6%) in those not receiving defibrotide. Resolution rate of VOD at day +100 was 51% in the defibrotide group and 29% in the nondefibrotide group (difference, 22.1%; 95% CI, 2.6% to 42%). The results of our study are consistent with previously reported experiences with defibrotide, confirm the poor outcome of this syndrome, and suggest defibrotide is effective in the treatment of severe VOD. Copyright © 2016 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  5. Defibrotide for Patients with Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome: Interim Results from a Treatment IND Study.

    PubMed

    Richardson, Paul G; Smith, Angela R; Triplett, Brandon M; Kernan, Nancy A; Grupp, Stephan A; Antin, Joseph H; Lehmann, Leslie; Shore, Tsiporah; Iacobelli, Massimo; Miloslavsky, Maja; Hume, Robin; Hannah, Alison L; Nejadnik, Bijan; Soiffer, Robert J

    2017-06-01

    Hepatic veno-occlusive disease, or sinusoidal obstruction syndrome (VOD/SOS), is a serious and potentially fatal complication of conditioning for hematopoietic stem cell transplantation (HSCT) or of chemotherapy regimens alone. Defibrotide is a complex mixture of single-stranded polydeoxyribonucleotides that is approved in the United States for treating hepatic VOD/SOS with renal or pulmonary dysfunction post-HSCT and in the European Union, Israel, and South Korea for treating severe hepatic VOD/SOS post-HSCT. Defibrotide was previously available in the United States as an investigational drug through a treatment protocol (treatment IND) study. Interim results of that large, treatment IND study of patients with VOD/SOS and with or without multiorgan dysfunction (MOD; also known as multiorgan failure) are presented here. Defibrotide was administered i.v. at 6.25 mg/kg every 6 hours (25 mg/kg/day), with a recommended treatment duration of at least 21 days. Enrolled patients (n = 681) were diagnosed with VOD/SOS based on Baltimore or modified Seattle criteria or liver biopsy analysis. Among the 573 HSCT recipients, 288 (50.3%; 95% confidence interval [CI], 46.2% to 54.4%) were alive at day +100 post-HSCT. Day +100 survival for the pediatric (≤16 years) and adult (>16 years) subgroups was 54.5% (95% CI, 49.1% to 60.0%; n = 174 of 319) and 44.9% (95% CI, 38.8% to 51.0%; n = 114 of 254), respectively. In the MOD subgroup, 159 of 351 patients (45.3%; 95% CI, 40.1% to 50.5%) of patients were alive at day +100 post-HSCT. Treatment with defibrotide was generally well tolerated, and drug-related toxicities were consistent with previous studies. Adverse events were reported in 69.6% of safety-evaluable patients (399 of 573). Other than VOD/SOS and associated MOD symptoms, the most commonly reported treatment-emergent adverse event was hypotension (13.8%). Day +100 survival results observed in this trial were consistent with results seen in previous trials of defibrotide for VOD/SOS in adult and pediatric patients. These data support the potential benefit of defibrotide in treating a VOD/SOS patient population that includes those with and without MOD. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  6. Defibrotide for the treatment of hepatic veno-occlusive disease in children after hematopoietic stem cell transplantation.

    PubMed

    Corbacioglu, Selim; Kernan, Nancy; Lehmann, Leslie; Brochstein, Joel; Revta, Carolyn; Grupp, Stephan; Martin, Paul; Richardson, Paul G

    2012-06-01

    Hepatic veno-occlusive disease (VOD) is a serious complication of stem cell transplantation in children. VOD is characterized by rapid weight gain, hepatomegaly, hyperbilirubinemia and ascites. The pathogenesis of VOD is thought to involve chemotherapy and radiation-induced damage to the sinusoidal endothelium, resulting in endothelial injury, microthrombosis, subendothelial damage and cytokine activation. These processes lead to concomitant progressive hepatocellular dysfunction and subsequent fluid retention and renal impairment. Severe VOD is typically associated with multiorgan failure and high mortality. A number of possible strategies for the prevention and/or treatment of VOD in children have been investigated. The most promising agent to date is defibrotide, a novel polydeoxyribonucleotide with fibrinolytic properties but no major bleeding risk. Numerous studies, including Phase II/III trials, have shown clinical benefit in pediatric patients with the use of defibrotide treatment and prophylaxis. This review discusses VOD in children and focuses on therapeutic options, including defibrotide, in this patient population.

  7. Safety and efficacy of defibrotide for the treatment of severe hepatic veno-occlusive disease.

    PubMed

    Richardson, Paul G; Ho, Vincent T; Giralt, Sergio; Arai, Sally; Mineishi, Shin; Cutler, Corey; Antin, Joseph H; Stavitzski, Nicole; Niederwieser, Dietger; Holler, Ernst; Carreras, Enric; Soiffer, Robert

    2012-08-01

    Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome, is a potentially life-threatening complication of chemotherapeutic conditioning used in preparation for hematopoietic stem-cell transplantation (SCT). VOD may occur in up to 62% of patients undergoing SCT, with onset generally within the first month after SCT. In severe cases, 100-day mortality is in excess of 80%. Current management consists of best supportive care, with no agents to date approved for treatment in the USA or the EU. Defibrotide, a polydisperse oligonucleotide, has been shown in phase II and III trials to improve complete response and survival in patients undergoing SCT with severe VOD. This article reviews our current understanding of VOD, and examines recent clinical findings on defibrotide for the treatment and prophylaxis of VOD.

  8. Combination of High-Dose Methylprednisolone and Defibrotide for Veno-Occlusive Disease in Pediatric Hematopoietic Stem Cell Transplant Recipients.

    PubMed

    Gloude, Nicholas J; Jodele, Sonata; Teusink-Cross, Ashley; Grimley, Michael; Davies, Stella M; Lane, Adam; Myers, Kasiani C

    2018-01-01

    Veno-occlusive disease (VOD) is a serious complication of hematopoietic stem cell transplant (HSCT), with high mortality in severe cases and until recently very limited therapeutic options consisting largely of supportive care. Defibrotide was recently approved in the United States for the treatment of severe VOD in patients with renal or pulmonary dysfunction after HSCT. Our group previously published on the use of high-dose methylprednisolone (500 mg/m 2 per dose every 12 hours for 6 doses) in patients with VOD, showing good success. A small subset of these individuals were also treated with defibrotide, but additional studies using the combination of high-dose methylprednisolone and defibrotide for the treatment of VOD are lacking. We present a single-institution retrospective chart review of 15 HSCT patients with VOD treated with the combination of high-dose methylprednisolone and defibrotide. VOD developed at a median of 17 days post-HSCT, and combination therapy was initiated within 1 day of VOD diagnosis. Twelve of 15 patients (80%) had multiorgan failure. Our single-center experience using both high-dose methylprednisolone and defibrotide showed a day +100 survival rate of 73% and an overall VOD complete resolution rate of 66.7%, higher than the rates reported in the recent literature using defibrotide alone (40% to 50% day +100 overall survival). These data suggest that the combination of high-dose steroids and defibrotide may be superior to defibrotide alone and warrant further investigation. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  9. Drug safety evaluation of defibrotide.

    PubMed

    Richardson, Paul G; Corbacioglu, Selim; Ho, Vincent Trien-Vinh; Kernan, Nancy A; Lehmann, Leslie; Maguire, Craig; Maglio, Michelle; Hoyle, Margaret; Sardella, Marco; Giralt, Sergio; Holler, Ernst; Carreras, Enric; Niederwieser, Dietger; Soiffer, Robert

    2013-01-01

    Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of chemotherapeutic conditioning used in preparation for hematopoietic stem-cell transplantation (SCT). Defibrotide (DF) has been shown in Phase II and III trials to improve complete response in patients with severe VOD (sVOD). None of the articles, to date, provide a comprehensive review of the safety of DF in VOD and/or a range of other conditions. This article reviews current clinical findings on DF, primarily in terms of safety for use in treatment and prophylaxis of VOD, and relevant safety data for its use in other diseases. The literature review was conducted using a PubMed search with the fixed term 'defibrotide' in combination with ≥ 1 of 'safety', 'veno-occlusive disease' (with and without 'treatment', 'prevention'), 'oncology', 'myeloma', 'microangiopathy', 'anti-thrombotic' and 'peripheral vascular disorder'. Related articles from the EBMT and ASH conference websites were also included. DF was well tolerated in majority of the studies. The safety profile of DF is largely favourable with toxicities comparable to control populations in the setting of SCT complicated by sVOD.

  10. Designing a scalable video-on-demand server with data sharing

    NASA Astrophysics Data System (ADS)

    Lim, Hyeran; Du, David H.

    2000-12-01

    As current disk space and transfer speed increase, the bandwidth between a server and its disks has become critical for video-on-demand (VOD) services. Our VOD server consists of several hosts sharing data on disks through a ring-based network. Data sharing provided by the spatial-reuse ring network between servers and disks not only increases the utilization towards full bandwidth but also improves the availability of videos. Striping and replication methods are introduced in order to improve the efficiency of our VOD server system as well as the availability of videos. We consider tow kinds of resources of a VOD server system. Given a representative access profile, our intention is to propose an algorithm to find an initial condition, place videos on disks in the system successfully. If any copy of a video cannot be placed due to lack of resources, more servers/disks are added. When all videos are place on the disks by our algorithm, the final configuration is determined with indicator of how tolerable it is against the fluctuation in demand of videos. Considering it is a NP-hard problem, our algorithm generates the final configuration with O(M log M) at best, where M is the number of movies.

  11. Designing a scalable video-on-demand server with data sharing

    NASA Astrophysics Data System (ADS)

    Lim, Hyeran; Du, David H. C.

    2001-01-01

    As current disk space and transfer speed increase, the bandwidth between a server and its disks has become critical for video-on-demand (VOD) services. Our VOD server consists of several hosts sharing data on disks through a ring-based network. Data sharing provided by the spatial-reuse ring network between servers and disks not only increases the utilization towards full bandwidth but also improves the availability of videos. Striping and replication methods are introduced in order to improve the efficiency of our VOD server system as well as the availability of videos. We consider tow kinds of resources of a VOD server system. Given a representative access profile, our intention is to propose an algorithm to find an initial condition, place videos on disks in the system successfully. If any copy of a video cannot be placed due to lack of resources, more servers/disks are added. When all videos are place on the disks by our algorithm, the final configuration is determined with indicator of how tolerable it is against the fluctuation in demand of videos. Considering it is a NP-hard problem, our algorithm generates the final configuration with O(M log M) at best, where M is the number of movies.

  12. Safety and efficacy of defibrotide for the treatment of severe hepatic veno-occlusive disease

    PubMed Central

    Ho, Vincent T.; Giralt, Sergio; Arai, Sally; Mineishi, Shin; Cutler, Corey; Antin, Joseph H.; Stavitzski, Nicole; Niederwieser, Dietger; Holler, Ernst; Carreras, Enric; Soiffer, Robert

    2012-01-01

    Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome, is a potentially life-threatening complication of chemotherapeutic conditioning used in preparation for hematopoietic stem-cell transplantation (SCT). VOD may occur in up to 62% of patients undergoing SCT, with onset generally within the first month after SCT. In severe cases, 100-day mortality is in excess of 80%. Current management consists of best supportive care, with no agents to date approved for treatment in the USA or the EU. Defibrotide, a polydisperse oligonucleotide, has been shown in phase II and III trials to improve complete response and survival in patients undergoing SCT with severe VOD. This article reviews our current understanding of VOD, and examines recent clinical findings on defibrotide for the treatment and prophylaxis of VOD. PMID:23606935

  13. Prevention of veno-occlusive disease with defibrotide after allogeneic stem cell transplantation.

    PubMed

    Chalandon, Yves; Roosnek, Eddy; Mermillod, Bernadette; Newton, Anita; Ozsahin, Hulya; Wacker, Pierre; Helg, Claudine; Chapuis, Bernard

    2004-05-01

    Veno-occlusive disease (VOD) of the liver occurs in 10% to 50% of patients after allogeneic stem cell transplantation, ranging from mild reversible disease to severe disease, with a mortality rate almost always close to 100%. Recently, promising results in the treatment of established VOD with defibrotide were reported. Therefore, defibrotide may be used as a prophylactic regimen for hepatic VOD in stem cell transplantation for hematologic malignancies. Fifty-two successive patients who underwent transplantation between October 1999 and June 2002 received defibrotide prophylaxis intravenously from day -7 to day +20 after transplantation in addition to heparin and were compared with historical controls who underwent transplantation successively between February 1997 and September 1999. In the defibrotide group, the maximum total bilirubin levels and the number of patients with serum levels exceeding 50 micromol/L were significantly lower than in the control group (5 of 52 versus 18 of 52, respectively; P =.004). None of the 52 patients developed VOD (Baltimore criteria), and no side effects occurred. These results were significantly different (P =.001) from controls (10/52 [19%] with VOD, 3 of whom died of severe VOD). In addition, day 100 event-free survival was significantly higher in the study group (P =.02), with a trend toward better day 100 overall survival (P =.07). These results suggest that defibrotide given in addition to heparin may be an efficient prophylaxis for VOD.

  14. High-Dose Methylprednisolone for Veno-Occlusive Disease of the Liver in Pediatric Hematopoietic Stem Cell Transplantation Recipients

    PubMed Central

    Myers, Kasiani C.; Lawrence, Julia; Marsh, Rebecca A.; Davies, Stella M.; Jodele, Sonata

    2017-01-01

    Veno-occlusive disease (VOD) of the liver is a well-recognized serious complication of hematopoietic stem cell transplantation (HSCT), with few successful treatment modalities available for severe disease. Some reports have demonstrated success in adults with the use of high-dose steroid therapy, but experience in the pediatric population is lacking. We retrospectively reviewed HSCT patients treated at our institution since 2003 and identified 15 (2.4%) who developed VOD. Of these, nine (60%) were treated with intravenous high-dose methylprednisolone (500 mg/m2 per dose every 12 hours for six doses). Steroid therapy was initiated at or before first ultrasound evidence of reversal of portal venous flow and before meeting criteria for initiation of defibrotide therapy. Four patients were also treated with defibrotide starting 2 to 5 days after initiation of steroids. Eight of nine patients (88%) with VOD were diagnosed with multiorgan failure. Response to high-dose steroid therapy as defined by decrease in bilirubin by 50% in 10 days from therapy initiation was noted in six of nine patients (67%), occurring within 3 to 6 days of steroid therapy. Two patients died from multiorgan failure due to VOD. Seven survivors of VOD recovered at the median 6 days (range, 5 to 38) from VOD diagnosis. Overall, VOD survival as a group was 78%; however, survival among responders was 100%. No serious toxicities related to high-dose steroid therapy were observed. We conclude that high-dose steroid therapy if initiated early may reverse VOD of the liver in pediatric HSCT patients, abrogating the need for defibrotide therapy with its associated toxicities and regulatory difficulties. PMID:23211838

  15. Veno-Occlusive Disease of the Liver in the Absence of Elevation in Bilirubin in Pediatric Patients after Hematopoietic Stem Cell Transplantation

    PubMed Central

    Myers, Kasiani C.; Dandoy, Christopher; El-Bietar, Javier; Davies, Stella M.; Jodele, Sonata

    2016-01-01

    Veno-occlusive disease (VOD) of the liver is a well-described and significant complication of hematopoietic stem cell transplantation (HSCT), with limited successful therapeutic options in severe cases. Prompt diagnosis and initiation of treatment is crucial to restrict the extent of disease. However, a subset of patients may not meet all current diagnostic criteria at presentation, and waiting for these to be met may delay therapy. We retrospectively reviewed 794 HSCT patients treated at our institution between 2003 and 2013, identifying 17 (2.1%) who developed VOD. Of these, 5 (29%) were noted to have an absence of elevated bilirubin at the time of VOD diagnosis and reversal of portal venous flow on ultrasound. Median total and conjugated bilirubin at VOD diagnosis were 1.0 and 0.2 mg/dL, respectively. All 5 patients were subsequently diagnosed with multiorgan failure associated with VOD, including 1 with encephalopathy. Four were treated with intravenous high-dose methylprednisolone (500 mg/m2 per dose every 12 hours for 6 doses). One patient received defibrotide therapy in addition to steroids and another supportive care alone. VOD resolved in 4 of 5 patients, with median time to resolution of VOD, defined as recovery of all organ function and normalization of bilirubin and portal venous flow, of 8 days. Two patients died later from progressive primary disease and chronic graft-versus-host disease, respectively. We conclude that a high index of suspicion for VOD should be maintained in patients despite lack of bilirubin elevation in the presence of other diagnostic criteria such as hepatomegaly, abdominal pain, ascites, or weight gain. Early ultrasound evaluation in these patients may lead to more timely diagnosis and therapeutic interventions. PMID:25300869

  16. Defibrotide sodium for the treatment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome.

    PubMed

    Richardson, Paul G; Triplett, Brandon M; Ho, Vincent T; Chao, Nelson; Dignan, Fiona L; Maglio, Michelle; Mohty, Mohamad

    2018-02-01

    Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is an unpredictable condition associated with endothelial-cell damage due to conditioning for hematopoietic stem-cell transplantation (HSCT) or chemotherapy without HSCT. Mortality in patients with VOD/SOS and multi-organ dysfunction (MOD) may be >80%. Areas covered: Defibrotide is the only approved drug for the treatment of severe hepatic VOD/SOS after HSCT in the European Union and hepatic VOD/SOS with renal or pulmonary dysfunction in the United States. Its efficacy in patients with VOD/SOS with MOD post-HSCT was demonstrated in a clinical-trial program that included a historically controlled treatment study, a phase 2 trial, and a large T-IND expanded-access program that also included patients without MOD and who received chemotherapy without HSCT. Expert commentary: Defibrotide appears to protect endothelial cells and restore the thrombolytic-fibrinolytic balance. It addresses a significant clinical need and has demonstrated favorable Day +100 survival and overall adverse-event rates that seem similar to control groups receiving supportive care alone. Currently, defibrotide is under investigation for the prevention of VOD/SOS in high-risk pediatric and adult patients.

  17. Hepatic veno-occlusive disease after hematopoietic stem cell transplantation: review and update on the use of defibrotide.

    PubMed

    Ho, Vincent T; Linden, Erica; Revta, Carolyn; Richardson, Paul G

    2007-06-01

    Veno-occlusive disease (VOD) of the liver remains one of the most feared complications associated with high-dose chemotherapy and hematopoietic stem cell transplantation (SCT). As a clinical syndrome characterized by fluid retention, hyperbilirubinemia, and painful hepatomegaly, VOD incidence varies widely, but it is universally recognized that severe cases of VOD have an extremely poor prognosis, with mortality at day 100 after SCT in excess of 80%. Systemic anticoagulant and thrombolytic therapies have been tested extensively in this disease, but are largely ineffective and are associated with significant bleeding complications. In recent years, defibrotide (DF; a polydisperse oligonucleotide derived from porcine intestinal mucosa with antithrombotic and protective properties on the microvasculature but minimal hemorrhagic risk) has emerged as a promising therapy for VOD. In large, multicenter, international phase I/II trials targeting patients with severe VOD, DF has been associated with complete response rates between 36 and 60%, survival past transplant day 100 in the range of 32 to 50%, and few significant attributable side effects. On the basis of these encouraging results, a pivotal, prospective, multinational, phase III trial of DF is underway in patients with severe VOD, and should provide validation of this agent as a therapy for established disease with a high risk of mortality. This article reviews our current understanding of hepatic VOD after SCT and provides a summary of the data to date on the use of DF as both therapy and prophylaxis for this disease.

  18. Vestibulo-ocular dysfunction in pediatric sports-related concussion.

    PubMed

    Ellis, Michael J; Cordingley, Dean; Vis, Sara; Reimer, Karen; Leiter, Jeff; Russell, Kelly

    2015-09-01

    The objective of this study was 2-fold: 1) to examine the prevalence of vestibulo-ocular dysfunction (VOD) among children and adolescents with acute sports-related concussion (SRC) and postconcussion syndrome (PCS) who were referred to a multidisciplinary pediatric concussion program; and 2) to determine if VOD is associated with the development of PCS in this cohort. The authors conducted a retrospective review of all patients with acute SRC (presenting 30 days or less postinjury) and PCS (3 or more symptoms for at least 1 month) referred to a multidisciplinary pediatric concussion program between September 2013 and July 2014. Initial assessment included clinical history, physical examination, and Post-Concussion Symptom Scale assessment. Patients were also assessed for VOD, which was defined as more than one subjective vestibular and oculomotor complaint (dizziness, blurred vision, and so on) and more than one objective physical examination finding (abnormal smooth pursuits, saccades, vestibulo-ocular reflex, and so on). This study was approved by the local institutional ethics review board. A total of 101 patients (mean age 14.2 years, SD 2.3 years; 63 male and 38 female patients) participated, including 77 (76.2%) with acute SRC and 24 (23.8%) with PCS. Twenty-two of the 77 patients (28.6%) with acute SRC and 15 of the 24 (62.5%) with PCS met the clinical criteria for VOD. The median duration of symptoms was 40 days (interquartile range [IQR] 28.5-54 days) for patients with acute SRC who had VOD compared with 21 days (IQR 13-32 days) for those without VOD (p = 0.0001). There was a statistically significant increase in the adjusted odds of developing PCS among patients with acute SRC who had VOD compared with those without VOD (adjusted OR 4.10; 95% CI 1.04-16.16). Evidence of VOD was detected in a significant proportion of children and adolescents with acute SRC and PCS who were referred to a multidisciplinary pediatric concussion program. This clinical feature was a significant risk factor for the subsequent development of PCS in this pediatric acute SRC cohort.

  19. An Intercomparison of Vegetation Products from Satellite-based Observations used for Soil Moisture Retrievals

    NASA Astrophysics Data System (ADS)

    Vreugdenhil, Mariette; de Jeu, Richard; Wagner, Wolfgang; Dorigo, Wouter; Hahn, Sebastian; Bloeschl, Guenter

    2013-04-01

    Vegetation and its water content affect active and passive microwave soil moisture retrievals and need to be taken into account in such retrieval methodologies. This study compares the vegetation parameterisation that is used in the TU-Wien soil moisture retrieval algorithm to other vegetation products, such as the Vegetation Optical Depth (VOD), Net Primary Production (NPP) and Leaf Area Index (LAI). When only considering the retrieval algorithm for active microwaves, which was developed by the TU-Wien, the effect of vegetation on the backscattering coefficient is described by the so-called slope [1]. The slope is the first derivative of the backscattering coefficient in relation to the incidence angle. Soil surface backscatter normally decreases quite rapidly with the incidence angle over bare or sparsely vegetated soils, whereas the contribution of dense vegetation is fairly uniform over a large range of incidence angles. Consequently, the slope becomes less steep with increasing vegetation. Because the slope is a derivate of noisy backscatter measurements, it is characterised by an even higher level of noise. Therefore, it is averaged over several years assuming that the state of the vegetation doesn't change inter-annually. The slope is compared to three dynamic vegetation products over Australia, the VOD, NPP and LAI. The VOD was retrieved from AMSR-E passive microwave data using the VUA-NASA retrieval algorithm and provides information on vegetation with a global coverage of approximately every two days [2]. LAI is defined as half the developed area of photosynthetically active elements of the vegetation per unit horizontal ground area. In this study LAI is used from the Geoland2 products derived from SPOT Vegetation*. The NPP is the net rate at which plants build up carbon through photosynthesis and is a model-based estimate from the BiosEquil model [3, 4]. Results show that VOD and slope correspond reasonably well over vegetated areas, whereas in arid areas, where the microwave signals mostly stem from the soil surface and deeper soil layers, they are negatively correlated. A second comparison of monthly values of both vegetation parameters to modelled NPP data shows that particularly over dry areas the VOD corresponds better to the NPP, with r=0.79 for VOD-NPP and r=-0.09 for slope-NPP. 1. Wagner, W., et al., A Study of Vegetation Cover Effects on ERS Scatterometer Data. IEEE Transactions on Geoscience and Remote Sensing, 1999. 37(2): p. 938-948. 2. Owe, M., R. de Jeu, and J. Walker, A methodology for surface soil moisture and vegetation optical depth retrieval using the microwave polarization difference index. Geoscience and Remote Sensing, IEEE Transactions on, 2001. 39(8): p. 1643-1654. 3. Raupach, M.R., et al., Balances of Water, Carbon, Nitrogen and Phosphorus in Australian Landscapes: (1) Project Description and Results, 2001, Sustainable Minerals Institute, CSIRO Land and Water. 4. Raupach, M.R., et al., Balances of Water, Carbon, Nitrogen and Phosporus in Australian Landscapes: (2) Model Formulation and Testing, 2001, Sustainable Minerals Institute, CSIRO Land and Water. * These products are the joint property of INRA, CNES and VITO under copyright of Geoland2. They are generated from the SPOT VEGETATION data under copyright CNES and distribution by VITO.

  20. Validation of a Pressed Pentolite Donor for the Large Scale Gap Test (LGST) at DSTO

    DTIC Science & Technology

    2013-03-01

    20.5 a based on dent depth measurement and referenced to RT 60/40 3.1.3 Modelling Data The VoD and PCJ were calculated using CHEETAH 4.0...compositions as well as ideal explosives. It should be noted that CHEETAH assumes the charge is of infinite length as it can not model size effects. It can...calculated from CHEETAH 4.0 and Experimental data Donor Origin Density (g.cm-3) Calculated PCJ (GPa) Experimental P (GPa) Calculated VoD (m.s-1

  1. A Study of Carrier Based Aircraft Readiness Sustainability in the Event of External Air Logistic Support Deprivation

    DTIC Science & Technology

    1987-06-01

    equation for 7R investment has been used in combination with the linear equation for COD/VOD delivery to produce six " iso -readiness" lines. Each iso ...readiness line represents the value of inventory investment and days since last COD/VOD delivery required to maintain a specific level of FMC. The iso ...Truett, D.B., Manaaerial Economics, second edition, South-Western Publish..ng Co., 1984, p. 65. 158 Iso -Readiness Plot o80mna4C Mad" of ?R Ve COO/VOo WO

  2. Syndicated RSS Feeds for Course Information Distribution

    ERIC Educational Resources Information Center

    Glotzbach, Ronald J.; Mordkovich, Dorina A.; Radwan, Jaime E.

    2008-01-01

    Students in higher education today are technologically savvy and expect faculty to use myriad web technologies for course delivery. This includes taking advantage of email, course web sites, and online learning communities. However, expectations now also include RSS, blogs, web-, pod-, and vod-casting, extending the classroom experience to provide…

  3. [Central blood pressure and vascular damage].

    PubMed

    Pérez-Lahiguera, Francisco; Rodilla, Enrique; Costa, José Antonio; Pascual, José María

    2015-07-20

    The aim of this study was to assess the relationship between central blood pressure and vascular damage. This cross-sectional study involved 393 never treated hypertensive patients (166 women). Clinical blood pressure (BP), 24h blood pressure (BP24h) and central blood pressure (CBP) were measured. Vascular organ damage (VOD) was assessed by calculating the albumin/creatinine ratio (ACR), wave pulse pressure velocity and echocardiographic left ventricular mass index (LVMI). Patients with VOD had higher values of BP, BP24h, and CBP than patients without ACR. When comparing several systolic BP, systolic BP24h had a higher linear correlation with CBP (Z Steiger test: 2.26; P=.02) and LVMI (Z Steiger test: 3.23; P=.01) than PAC. In a multiple regression analysis corrected by age, sex and metabolic syndrome, all pressures were related with VOD but systolic BP24h showed the highest correlation. In a logistic regression analysis, having the highest tercile of systolic BP24h was the stronger predictor of VOD (multivariate odds ratio: 3.4; CI 95%: 2.5-5.5, P=.001). CBP does not have more correlation with VOD than other measurements of peripheral BP. Systolic BP24h is the BP measurement that best predicts VOD. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  4. Defibrotide for children and adults with hepatic veno-occlusive disease post hematopoietic cell transplantation.

    PubMed

    Corbacioglu, Selim; Richardson, Paul G

    2017-10-01

    Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a complication that is typically associated with conditioning for hematopoietic stem cell transplantation (HSCT). In patients with concomitant multi-organ dysfunction, mortality may be >80%. Recently, the European Society for Blood and Marrow Transplantation established separate criteria for diagnosis and severity of VOD/SOS for adults and children, to better reflect current understanding of the disease. Areas covered: This review provides an overview of post-HSCT hepatic VOD/SOS and defibrotide, including its pharmacological, clinical, and regulatory profile. In children and adults following HSCT, defibrotide is approved for the treatment of hepatic VOD/SOS with concomitant renal or pulmonary dysfunction in the United States and for the treatment of severe hepatic VOD/SOS in the European Union. Day +100 survival rates with defibrotide are superior to those of historical controls receiving best supportive care only, and safety profiles are similar. Expert commentary: Defibrotide appears to act through multiple mechanisms to restore thrombo-fibrinolytic balance and protect endothelial cells, and there are promising data on the use of defibrotide for VOD/SOS prophylaxis in high-risk children undergoing HSCT. An ongoing randomized controlled trial in children and adults will better assess the clinical value of defibrotide as a preventive medication.

  5. Estimating grassland curing with remotely sensed data

    NASA Astrophysics Data System (ADS)

    Chaivaranont, Wasin; Evans, Jason P.; Liu, Yi Y.; Sharples, Jason J.

    2018-06-01

    Wildfire can become a catastrophic natural hazard, especially during dry summer seasons in Australia. Severity is influenced by various meteorological, geographical, and fuel characteristics. Modified Mark 4 McArthur's Grassland Fire Danger Index (GFDI) is a commonly used approach to determine the fire danger level in grassland ecosystems. The degree of curing (DOC, i.e. proportion of dead material) of the grass is one key ingredient in determining the fire danger. It is difficult to collect accurate DOC information in the field, and therefore ground-observed measurements are rather limited. In this study, we explore the possibility of whether adding satellite-observed data responding to vegetation water content (vegetation optical depth, VOD) will improve DOC prediction when compared with the existing satellite-observed data responding to DOC prediction models based on vegetation greenness (normalised difference vegetation index, NDVI). First, statistically significant relationships are established between selected ground-observed DOC and satellite-observed vegetation datasets (NDVI and VOD) with an r2 up to 0.67. DOC levels estimated using satellite observations were then evaluated using field measurements with an r2 of 0.44 to 0.55. Results suggest that VOD-based DOC estimation can reasonably reproduce ground-based observations in space and time and is comparable to the existing NDVI-based DOC estimation models.

  6. Defibrotide for Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease Prophylaxis in High-Risk Adult Patients: A Single-Center Experience Study.

    PubMed

    Picod, Adrien; Bonnin, Agnès; Battipaglia, Giorgia; Giannotti, Federica; Ruggeri, Annalisa; Brissot, Eolia; Malard, Florent; Médiavilla, Clémence; Belhocine, Ramdane; Vekhoff, Anne; Gueye, Mor Sény; Lapusan, Simona; Adaeva, Rosa; Isnard, Françoise; Legrand, Ollivier; Baylatry, Minh-Tam; Joly, Anne-Christine; Labopin, Myriam; Duléry, Rémy; Mohty, Mohamad

    2018-03-01

    Sinusoidal obstruction syndrome (SOS), also known as hepatic veno-occlusive disease (VOD), is a serious complication after hematopoietic stem cell transplantation (HSCT). SOS/VOD usually occurs within 3 weeks of HSCT, but the 2016 European Society for Blood and Marrow Transplantation diagnosis criteria have been revised to include late forms. Prophylactic use of defibrotide is recommended in the pediatric setting, but its value remains uncertain in the adult population. We report here a single-center series of 63 adult patients considered at high risk for SOS/VOD who received defibrotide prophylaxis in combination with ursodeoxycholic acid between May 2012 and August 2016. The median duration of defibrotide therapy was 23 days. Bleeding occurred in 14 patients (21.5%). Defibrotide prophylaxis was discontinued in 7 patients (10.8%): 4 cases (6.3%) due to bleeding and 3 cases (4.6%) because of the need for antithrombotic therapy. Overall, SOS/VOD occurred in 4 cases (6.3%) within 21 days after HSCT (days 13 and 14) in 2 cases and late-onset SOS/VOD (days 57 and 58) in the other 2 cases. SOS/VOD was moderate in 1 case, very severe in 3 cases, with 2 deaths related to SOS/VOD. Cumulative incidence of grades II to IV acute graft-versus-host disease and transplant-associated thrombotic microangiopathy were 22.2% and 3.2%, respectively. With a median follow-up of 31 months (range, 10.7 to 60.3), the rates of 2-year overall survival, progression-free survival, incidence of relapse, and nonrelapse mortality were 56.5%, 49%, 28.7%, and 22.3%, respectively. In our experience defibrotide prophylaxis is associated with a low incidence of SOS/VOD after allogeneic HSCT in a high-risk adult population with an acceptable safety profile. Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  7. Defibrotide for the treatment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome following nontransplant-associated chemotherapy: Final results from a post hoc analysis of data from an expanded-access program.

    PubMed

    Kernan, Nancy A; Richardson, Paul G; Smith, Angela R; Triplett, Brandon M; Antin, Joseph H; Lehmann, Leslie; Messinger, Yoav; Liang, Wei; Hume, Robin; Tappe, William; Soiffer, Robert J; Grupp, Stephan A

    2018-06-06

    Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially fatal complication of conditioning for hematopoietic stem cell transplantation (HSCT) but can occur after nontransplant-associated chemotherapy. Following HSCT, VOD/SOS with multi-organ dysfunction (MOD) may be associated with >80% mortality. Defibrotide is approved to treat severe hepatic VOD/SOS post-HSCT in patients aged >1 month in the European Union and hepatic VOD/SOS with renal or pulmonary dysfunction post-HSCT in the United States. Prior to US approval, defibrotide was available to treat VOD/SOS through an expanded-access treatment (T-IND) program. A post hoc analysis of nontransplant-associated VOD/SOS patients treated with defibrotide initiated within 30 days of starting chemotherapy and followed for 70 days is presented. Patients were diagnosed by Baltimore or modified Seattle criteria or biopsy, and received defibrotide 25 mg/kg/day in four divided doses (≥21 days recommended). Of the 1,154 patients in the T-IND, 137 had nontransplant-associated VOD/SOS, 82 of whom developed VOD/SOS within 30 days of starting chemotherapy. Of them, 66 (80.5%) were aged ≤16 years. Across all the 82 patients, Kaplan-Meier estimated day +70 survival was 74.1%, 65.8% in patients with MOD (n = 38), and 81.3% in patients without MOD (n = 44). By age group, Kaplan-Meier estimated day +70 survival was 80.1% in pediatric patients (n = 66) and 50.0% in adults (n = 16). Treatment-related adverse events occurred in 26.8%. In this post hoc analysis of 82 patients initiating defibrotide within 30 days of starting chemotherapy, Kaplan-Meier estimated survival was 74.1% at 70 days after defibrotide initiation. Safety profile was consistent with prior defibrotide studies. © 2018 The Authors. Pediatric Blood & Cancer Published by Wiley Periodicals, Inc.

  8. Defibrotide for the Treatment of Hepatic Veno-Occlusive Disease: Final Results From the International Compassionate-Use Program.

    PubMed

    Corbacioglu, Selim; Carreras, Enric; Mohty, Mohamad; Pagliuca, Antonio; Boelens, Jaap Jan; Damaj, Gandhi; Iacobelli, Massimo; Niederwieser, Dietger; Olavarría, Eduardo; Suarez, Felipe; Ruutu, Tapani; Verdonck, Leo; Hume, Robin; Nejadnik, Bijan; Lai, Chinglin; Finetto, Giorgia; Richardson, Paul

    2016-10-01

    Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is an unpredictable and potentially fatal complication of hematopoietic cell transplantation (HCT) or nontransplantation-associated chemotherapy/radiotherapy. In cases of severe hepatic VOD/SOS, typically defined by associated multiorgan failure (MOF, also known as multiorgan dysfunction), mortality exceeds 80%. Preclinical and early clinical data have provided a rationale for defibrotide treatment in hepatic VOD/SOS. Based on this evidence and in recognition of the dismal prognosis for these patients, defibrotide was made available through an international multicenter compassionate-use program conducted from December 1998 to March 2009. Physicians participating in the program voluntarily provided demographic and outcome data for patients given defibrotide. Efficacy and safety analyses were performed using the data received for 710 treated patients. Defibrotide was given at 10, 25, 40, 60, or 80 mg/kg/day for a median of 15 days (range, 1 to 119 days). By Kaplan-Meier analysis, the estimated overall day +100 survival was 54% (58% in the 25 mg/kg/day dose group). Adverse events (AEs) were reported in 53% of patients. The most common AEs were MOF, progression of hepatic VOD/SOS, sepsis, and graft-versus-host disease, which were consistent with the AEs expected for this patient population. No clinically meaningful trends in AEs were identified by gender, age, or dose group. Safety and efficacy resultswere consistent with prior studies of defibrotide in hepatic VOD/SOS, and subgroup analyses lend support to the use of the 25 mg/kg/day dose. Copyright © 2016 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  9. Initializing carbon cycle predictions from the Community Land Model by assimilating global biomass observations

    NASA Astrophysics Data System (ADS)

    Fox, A. M.; Hoar, T. J.; Smith, W. K.; Moore, D. J.

    2017-12-01

    The locations and longevity of terrestrial carbon sinks remain uncertain, however it is clear that in order to predict long-term climate changes the role of the biosphere in surface energy and carbon balance must be understood and incorporated into earth system models (ESMs). Aboveground biomass, the amount of carbon stored in vegetation, is a key component of the terrestrial carbon cycle, representing the balance of uptake through gross primary productivity (GPP), losses from respiration, senescence and mortality over hundreds of years. The best predictions of current and future land-atmosphere fluxes are likely from the integration of process-based knowledge contained in models and information from observations of changes in carbon stocks using data assimilation (DA). By exploiting long times series, it is possible to accurately detect variability and change in carbon cycle dynamics through monitoring ecosystem states, for example biomass derived from vegetation optical depth (VOD), and use this information to initialize models before making predictions. To make maximum use of information about the current state of global ecosystems when using models we have developed a system that combines the Community Land Model (CLM) with the Data Assimilation Research Testbed (DART), a community tool for ensemble DA. This DA system is highly innovative in its complexity, completeness and capabilities. Here we described a series of activities, using both Observation System Simulation Experiments (OSSEs) and real observations, that have allowed us to quantify the potential impact of assimilating VOD data into CLM-DART on future land-atmosphere fluxes. VOD data are particularly suitable to use in this activity due to their long temporal coverage and appropriate scale when combined with CLM, but their absolute values rely on many assumptions. Therefore, we have had to assess the implications of the VOD retrieval algorithms, with an emphasis on detecting uncertainty due to assumptions and inputs in the algorithms that are incompatible with those encoded within CLM. It is probable that VOD describes changes in biomass more accurately than absolute values, so in additional to sequential assimilation of observations, we have tested alternative filter algorithms, and assimilating VOD anomalies.

  10. Defibrotide for the management of sinusoidal obstruction syndrome in patients who undergo haemopoietic stem cell transplantation.

    PubMed

    Coutsouvelis, John; Avery, Sharon; Dooley, Michael; Kirkpatrick, Carl; Spencer, Andrew

    2016-11-01

    Sinusoidal obstruction syndrome, previously known as veno-occlusive disease (VOD/SOS), is a complication in patients undergoing haemopoietic stem cell transplantation (HSCT). Severe VOD/SOS, including progression to multi-organ failure, has resulted in a mortality of greater than 80%. Defibrotide's varying pharmacological actions, particularly on endothelial cells, make it is a useful agent to consider for prophylaxis and treatment of VOD/SOS. Barriers to its routine use include the high acquisition cost and the fact that neither the oral or parenteral formulations are licensed products in many countries at this time. This review summarises available literature on the use of defibrotide in the management of VOD/SOS. Publications consist predominantly of single centre cohort studies and case series. Available evidence indicates that defibrotide is effective in the management of VOD/SOS. Using defibrotide prophylaxis should also be considered, especially in the paediatric setting, where there are available results from a large, open label, randomized controlled trial. Patient outcome data from the larger studies and compassionate programs can inform consensus recommendations on dosing regimen and criteria for the treatment of VOD/SOS with defibrotide in the adult population. The reviewed literature indicates an effective and safe dose for treatment is 25mg/kg/day, continued for at least 14days or until complete response is achieved. Further studies are required to determine the optimal dose and duration of treatment in both paediatric patients and adults. Recent recommendations and a phase 3 trial using historical controls indicate that defibrotide should be included as a pharmacotherapy option in protocols guiding management of VOD/SOS. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Defibrotide: a review of its use in severe hepatic veno-occlusive disease following haematopoietic stem cell transplantation.

    PubMed

    Keating, Gillian M

    2014-12-01

    Defibrotide (Defitelio(®)) was recently approved in the EU for the treatment of severe hepatic veno-occlusive disease (VOD), also known as sinusoidal obstructive syndrome, in haematopoietic stem cell transplantation (HSCT) therapy. It is indicated in adults, adolescents, children and infants over 1 month of age. Defibrotide is also available in the US via an expanded-access protocol. Defibrotide is thought to protect endothelial cells and restore the thrombo-fibrinolytic balance in VOD. In a multicentre, phase III trial, the complete response rate by day +100 (primary endpoint) was significantly higher, and mortality at day +100 was significantly lower, in patients with severe hepatic VOD and multiorgan failure following HSCT who received intravenous defibrotide 6.25 mg/kg every 6 h than in a group of historical controls. The efficacy of defibrotide in severe hepatic VOD following HSCT was also supported by findings from a phase II dose-finding study, compassionate-use data and information provided from an independent transplant registry. Intravenous defibrotide was generally well tolerated in patients with severe hepatic VOD following HSCT, and was not associated with an increased risk of haemorrhagic adverse events. In conclusion, defibrotide is the only agent approved (in the EU) for use in severe hepatic VOD following HSCT and represents a useful advance in the treatment of this condition.

  12. Prototype system of secure VOD

    NASA Astrophysics Data System (ADS)

    Minemura, Harumi; Yamaguchi, Tomohisa

    1997-12-01

    Secure digital contents delivery systems are to realize copyright protection and charging mechanism, and aim at secure delivery service of digital contents. Encrypted contents delivery and history (log) management are means to accomplish this purpose. Our final target is to realize a video-on-demand (VOD) system that can prevent illegal usage of video data and manage user history data to achieve a secure video delivery system on the Internet or Intranet. By now, mainly targeting client-server systems connected with enterprise LAN, we have implemented and evaluated a prototype system based on the investigation into the delivery method of encrypted video contents.

  13. Satellite passive microwaves for monitoring deforestation and drought-induced carbon losses in sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Brandt, M.; Wigneron, J. P.; Chave, J.; Tagesson, T.; Penuelas, J.; Ciais, P.; Rasmussen, K.; Tian, F.; Mbow, C.; Al-Yaari, A.; Rodriguez-Fernandez, N.; Zhang, W.; Kerr, Y. H.; Tucker, C. J.; Mialon, A.; Verger, A.; Fensholt, R.

    2017-12-01

    The African continent is facing one of the driest periods in the past three decades and continuing deforestation. These disturbances threaten vegetation carbon (C) stocks and highlight the need for an operational tool for monitoring carbon stock dynamics. Knowledge of the amount, distribution, and turnover of carbon in African vegetation is crucial for understanding the effects of human pressure and climate change, but the shortcomings of optical and radar satellite products and the lack of systematic field inventories have led to considerable uncertainty in documenting patterns and dynamics of carbon stocks, in particular for drylands. Static carbon maps have been developed, but the temporal dynamics of carbon stocks cannot be derived from the benchmark maps, impeding timely, repeated, and reliable carbon assessments. The Soil Moisture and Ocean Salinity (SMOS) mission launched in 2009 was the first passive microwave-based satellite system operating at L-band (1.4 GHz) frequency. The low frequencies allow the satellite to sense deep within the canopy layer with less influence by the green non-woody plant components. The vegetation optical depth (VOD) derived from SMOS, henceforth L-VOD, is thus less sensitive to saturation effects, marking an important step forward in the monitoring of carbon as a natural resource. In this study, we apply for the first time L-VOD to quantify the inter-annual dynamics of aboveground carbon stocks for the period 2010-2016. We use this new technique to document patterns of carbon gains and losses in sub-Saharan Africa with a focus of dryland response to recent dry years. Results show that drylands lost carbon at a rate of -0.06 Pg C y-1 associated with drying trends, while humid areas lost only -0.02 Pg C y-1. These trends reflect a high inter-annual variability with a very wet (2011) and a very dry year (2016) associated with carbon gains and losses respectively. This study demonstrates, first, the operational applicability of L-VOD to monitor the dynamics of carbon loss and gain due to climate variations and deforestation, and second, the importance of the highly dynamic and drought prone carbon pool of dryland savannahs for the global carbon balance, despite the relatively low carbon stock per unit area.

  14. Defibrotide for the treatment of veno-occlusive disease after liver transplantation.

    PubMed

    Mor, E; Pappo, O; Bar-Nathan, N; Shaharabani, E; Shapira, Z; Tur-Kaspa, R; Ben-Ari, Z

    2001-10-15

    Veno-occlusive disease (VOD) after liver transplantation is associated with acute rejection and poor outcome. The use of antithrombotic and thrombolytic agents is limited by their toxicity. Defibrotide is a polydeoxyribonucleotide with thrombolytic and antithrombotic properties and no systemic anticoagulant effect. Defibrotide, 35-40 mg/kg/day, was administered intravenously for 21 days on a compassionate-use basis to two patients aged 66 and 49 years. VOD had developed 6 weeks and 4 months after orthotopic liver transplantation for hepatitis C and hepatitis B infection, respectively. VOD was diagnosed clinically by findings of weight gain (8.5% and 16%), ascites, jaundice (serum bilirubin 5.4 mg/dl and 21.7 mg/dl), and severe coagulopathy (in one patient), and histologically by the presence of hemorrhagic centrilobular necrosis and fibrous stenosis of the hepatic venules. One of the patients had received azathioprine as part of the immunosuppressive regimen. There was no evidence of acute cellular rejection histologically. After 3 weeks of defibrotide administration, the first patient showed complete clinical resolution of the VOD, and serum bilirubin level normalized. He is alive 6 months after transplantation. The second patient, treated at a later stage of disease, showed marked improvement in the coagulopathic state, but there was no resolution of the VOD. He died 2 months later of multiorgan failure due to Escherichia coli sepsis. Neither patient had side effects from the drug. Defibrotide is a promising drug for the treatment of VOD after liver transplantation and needs to be evaluated in large, prospective studies.

  15. Determination of microwave vegetation optical depth and water content in the source region of the Yellow River

    NASA Astrophysics Data System (ADS)

    Liu, R.; Wen, J.; Wang, X.

    2017-12-01

    In this study, we use dual polarization brightness temperature observational data at the K frequency band collected by the Micro Wave Radiation Imager (MWRI) on board the Fengyun-3B satellite (FY-3B) to improve the τ-ω model by considering the contribution of water bodies in the pixels to radiation in the wetland area of the Yellow River source region. We define a dual polarization slope parameter and express the surface emissivity in the τ-ω model as the sum of the soil and water body emissivity to retrieve the vegetation optical depth (VOD); however, in regions without water body coverage, we still use the τ-ω model to solve for the VOD. By using the field observation data on the vegetation water content (VWC) in the source region of the Yellow River during the summer of 2012, we establish the regression relationship between the VOD and VWC and retrieve the spatial distribution of the VWC. The results indicate that in the entire source region of the Yellow River in 2012, the VOD was in the range of 0.20-1.20 and the VWC was in the range of 0.20 to 1.40, thereby exhibiting a trend of low values in the west and high values in the east. The area with the largest regional variation is along the Yellow River. We compare the results from remote-sensing estimated and ground-measured vegetation water content, and the root-mean-square error is 0.12. The analysis results indicated that by considering the coverage of seasonal wetlands in the source region of the Yellow River, the microwave remote sensing data collected by the FY-3B MWRI can be used to retrieve the vegetation water content in the source region of the Yellow River.

  16. Assessing the value of delay to truckers and carriers.

    DOT National Transportation Integrated Search

    2011-07-01

    This project evaluates the value of delay (VOD) to commercial vehicle operators due to highway congestion. : The VOD for congestion is a fundamental parameter driving the private sectors response to public freight : projects and policies such as c...

  17. Assessing the value of delay to truckers and carriers.

    DOT National Transportation Integrated Search

    2011-07-01

    This project evaluates the value of delay (VOD) to commercial vehicle operators due to highway congestion. The VOD for : congestion is a fundamental parameter driving the private sectors response to public freight projects and policies such as cor...

  18. Prophylactic defibrotide in allogeneic stem cell transplantation: minimal morbidity and zero mortality from veno-occlusive disease.

    PubMed

    Dignan, F; Gujral, D; Ethell, M; Evans, S; Treleaven, J; Morgan, G; Potter, M

    2007-07-01

    Veno-occlusive disease (VOD) is a common and high-risk complication of allogeneic stem cell transplantation (SCT). Defibrotide has recently been used successfully to treat the disorder. We report on 58 patients who received defibrotide prophylaxis without concurrent heparin. No patients fulfilled the Baltimore criteria for VOD or died of the condition within 100 days of SCT. None of this group developed haemorrhagic complications secondary to defibrotide. These observations suggest that prophylaxis with defibrotide alone may reduce the incidence of VOD post-SCT although a randomised controlled trial is warranted to further evaluate its role.

  19. Comparison of soil moisture retrieval algorithms based on the synergy between SMAP and SMOS-IC

    NASA Astrophysics Data System (ADS)

    Ebrahimi-Khusfi, Mohsen; Alavipanah, Seyed Kazem; Hamzeh, Saeid; Amiraslani, Farshad; Neysani Samany, Najmeh; Wigneron, Jean-Pierre

    2018-05-01

    This study was carried out to evaluate possible improvements of the soil moisture (SM) retrievals from the SMAP observations, based on the synergy between SMAP and SMOS. We assessed the impacts of the vegetation and soil roughness parameters on SM retrievals from SMAP observations. To do so, the effects of three key input parameters including the vegetation optical depth (VOD), effective scattering albedo (ω) and soil roughness (HR) parameters were assessed with the emphasis on the synergy with the VOD product derived from SMOS-IC, a new and simpler version of the SMOS algorithm, over two years of data (April 2015 to April 2017). First, a comprehensive comparison of seven SM retrieval algorithms was made to find the best one for SM retrievals from the SMAP observations. All results were evaluated against in situ measurements over 548 stations from the International Soil Moisture Network (ISMN) in terms of four statistical metrics: correlation coefficient (R), root mean square error (RMSE), bias and unbiased RMSE (UbRMSE). The comparison of seven SM retrieval algorithms showed that the dual channel algorithm based on the additional use of the SMOS-IC VOD product (selected algorithm) led to the best results of SM retrievals over 378, 399, 330 and 271 stations (out of a total of 548 stations) in terms of R, RMSE, UbRMSE and both R & UbRMSE, respectively. Moreover, comparing the measured and retrieved SM values showed that this synergy approach led to an increase in median R value from 0.6 to 0.65 and a decrease in median UbRMSE from 0.09 m3/m3 to 0.06 m3/m3. Second, using the algorithm selected in a first step and defined above, the ω and HR parameters were calibrated over 218 rather homogenous ISMN stations. 72 combinations of various values of ω and HR were used for the calibration over different land cover classes. In this calibration process, the optimal values of ω and HR were found for the different land cover classes. The obtained results indicated that the impact of the VOD parameter on SM retrievals is more considerable than the effects of HR and ω. Overall, the inclusion of the VOD parameter in the SMAP SM retrieval algorithm was found to be a very interesting approach and showed the large potential benefit of the synergy between SMAP and SMOS.

  20. Comparing land surface phenology derived from satellite and GPS network microwave remote sensing.

    PubMed

    Jones, Matthew O; Kimball, John S; Small, Eric E; Larson, Kristine M

    2014-08-01

    The land surface phenology (LSP) start of season (SOS) metric signals the seasonal onset of vegetation activity, including canopy growth and associated increases in land-atmosphere water, energy and carbon (CO2) exchanges influencing weather and climate variability. The vegetation optical depth (VOD) parameter determined from satellite passive microwave remote sensing provides for global LSP monitoring that is sensitive to changes in vegetation canopy water content and biomass, and insensitive to atmosphere and solar illumination constraints. Direct field measures of canopy water content and biomass changes desired for LSP validation are generally lacking due to the prohibitive costs of maintaining regional monitoring networks. Alternatively, a normalized microwave reflectance index (NMRI) derived from GPS base station measurements is sensitive to daily vegetation water content changes and may provide for effective microwave LSP validation. We compared multiyear (2007-2011) NMRI and satellite VOD records at over 300 GPS sites in North America, and their derived SOS metrics for a subset of 24 homogenous land cover sites to investigate VOD and NMRI correspondence, and potential NMRI utility for LSP validation. Significant correlations (P<0.05) were found at 276 of 305 sites (90.5 %), with generally favorable correspondence in the resulting SOS metrics (r (2)=0.73, P<0.001, RMSE=36.8 days). This study is the first attempt to compare satellite microwave LSP metrics to a GPS network derived reflectance index and highlights both the utility and limitations of the NMRI data for LSP validation, including spatial scale discrepancies between local NMRI measurements and relatively coarse satellite VOD retrievals.

  1. Escalation to High Dose Defibrotide in Patients with Hepatic Veno-Occlusive Disease

    PubMed Central

    Triplett, Brandon M.; Kuttab, Hani I.; Kang, Guolian; Leung, Wing

    2015-01-01

    Hepatic veno-occlusive disease (VOD) is a serious complication of high-dose chemotherapy regimens, such as those utilized in hematopoietic cell transplantation recipients. Defibrotide is considered a safe and effective treatment when dosed at 25 mg/kg/day. However, patients who develop VOD still have increased mortality despite the use of defibrotide. Data are limited on the use of doses above 60 mg/kg/day for persistent VOD. In this prospective clinical trial, 34 patients received escalating doses of defibrotide. For patients with persistent VOD despite doses of 60 mg/kg/day, doses were increased to a maximum of 110 mg/kg/day. There was no observed increase in toxicity until doses rose beyond 100 mg/kg/day. Patients receiving doses between 10–100 mg/kg/day experienced an average of 3 bleeding episodes per 100 days of treatment, while those receiving doses >100 mg/kg/day experienced 13.2 bleeding episodes per 100 days (p=0.008). Moreover, dose reductions due to toxicity were needed at doses of 110 mg/kg/day more often than at lower doses. Defibrotide may be safely escalated to doses well above the current standard without an increase in bleeding risk. However, the efficacy of this dose escalation strategy remains unclear, as outcomes were similar to published cohorts of patients receiving standard doses of defibrotide for VOD. PMID:26278046

  2. Consensus Report by the Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees on Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents, Part 3: Focus on Cardiorespiratory Dysfunction, Infections, Liver Dysfunction, and Delirium.

    PubMed

    Ovchinsky, Nadia; Frazier, Warren; Auletta, Jeffery J; Dvorak, Christopher C; Ardura, Monica; Song, Enkyung; McArthur, Jennifer; Jeyapalan, Asumthia; Tamburro, Robert; Mahadeo, Kris M; Traube, Chani; Duncan, Christine N; Bajwa, Rajinder P S

    2018-02-01

    Some patients with veno-occlusive disease (VOD) have multiorgan dysfunction, and multiple teams are involved in their daily care in the pediatric intensive care unit. Cardiorespiratory dysfunction is critical in these patients, requiring immediate action. The decision of whether to use a noninvasive or an invasive ventilation strategy may be difficult in the setting of mucositis or other comorbidities in patients with VOD. Similarly, monitoring of organ functions may be very challenging in these patients, who may have fulminant hepatic failure with or without hepatic encephalopathy complicated by delirium and/or infections. In this final guideline of our series on supportive care in patients with VOD, we address some of these questions and provide evidence-based recommendations on behalf of the Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  3. Assessment of Vegetation Responses and Sensitivity to the Millennium Drought in Australia

    NASA Astrophysics Data System (ADS)

    Jiao, T.; Williams, C. A.

    2016-12-01

    During the period from 1997 to 2009, Australia experienced one of the most severe and persistent drought known as the Millennium Drought (MD). Major water shortages were reported across the Australian continent as well as a great many tree mortality during and post this drought event. Given the projection of hotter and drier conditions for much of the continent, it is critical to analyze the impacts of climate extremes like MD as an indicator of possible impacts of future trends. Despite many field investigation, large-area monitoring of vegetation decline from MD remains lacking. Here, multi-source remote sensing datasets and novel methods were employed to assess the impacts of MD on vegetation in Australia in terms of the magnitude and sensitivity. Vegetation variables examined include fraction of photosynthetically absorbed radiation (fPar), vegetation optical depth (VOD) and aboveground biomass (AGB). Drought indicators are calculated based on precipitation and potential evapotranspiration from meteorological data. We found consistent spatial patterns in drought-induced declines among fPar, VOD and AGB. Common declines were observed in the east of New South Wales (NSW), the southeast of Queensland, the center and east of Victoria, and Tasmania. Severe declines (>0.2) in fPar concentrate in open forests and shrub lands while regions with more than 0.1 of decline in VOD are found widely across biome types. The net decrease in AGB could reach more than 20 Mg C per ha in the west of Victoria and the southwest of NSW. Sensitivity analysis shows that forests followed by herbaceous are more sensitive to drought than shrubs in terms of declines in fPar and VOD. In addition, vegetation tends to have larger sensitivity in semi-arid or semi-mesic regions than in areas that are either too dry or too wet.

  4. Escalation to High-Dose Defibrotide in Patients with Hepatic Veno-Occlusive Disease.

    PubMed

    Triplett, Brandon M; Kuttab, Hani I; Kang, Guolian; Leung, Wing

    2015-12-01

    Hepatic veno-occlusive disease (VOD) is a serious complication of high-dose chemotherapy regimens, such as those used in hematopoietic cell transplantation recipients. Defibrotide is considered a safe and effective treatment when dosed at 25 mg/kg/day. However, patients who develop VOD still have increased mortality despite the use of defibrotide. Data are limited on the use of doses above 60 mg/kg/day for persistent VOD. In this prospective clinical trial 34 patients received escalating doses of defibrotide. For patients with persistent VOD despite doses of 60 mg/kg/day, doses were increased to a maximum of 110 mg/kg/day. Increased toxicity was not observed until doses rose beyond 100 mg/kg/day. Patients receiving doses between 10 and 100 mg/kg/day experienced an average of 3 bleeding episodes per 100 days of treatment, whereas those receiving doses >100 mg/kg/day experienced 13.2 bleeding episodes per 100 days (P = .008). Moreover, dose reductions due to toxicity were needed at doses of 110 mg/kg/day more often than at lower doses. Defibrotide may be safely escalated to doses well above the current standard without an increase in bleeding risk. However, the efficacy of this dose-escalation strategy remains unclear, because outcomes were similar to published cohorts of patients receiving standard doses of defibrotide for VOD. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  5. Overview of Explosive Initiators

    DTIC Science & Technology

    2015-11-01

    of a relatively small stimulus, be it impact, friction, shock, heat, or electrostatic discharge (ref. 2). On the whole, they tend to be less potent...5200 RDX 7.5 120 > 250 1.82 205 8750 ESD – electrostatic discharge DSC – differential scanning calorimetry VOD – velocity of detonation Current...Center P.O. Box 8000 Corona , CA 91718-8000 gidep@gidep.org UNCLASSIFIED Approved for public release; distribution is unlimited. 18 Steven M. Nicolich Steven M. Nicolich Andrew Pskowski

  6. Does defibrotide induce a delay to polymorphonuclear neutrophil engraftment after hematopoietic stem cell transplantation? Observation in a pediatric population.

    PubMed

    Maximova, Natalia; Pizzol, Antonio; Giurici, Nagua; Granzotto, Marilena

    2015-04-01

    In recent years, defibrotide (DFT) has emerged as a promising therapy for veno-occlusive disease (VOD). The aim of this study was to investigate whether DFT prophylaxis affects neutrophil engraftment in patients undergoing hematopoietic stem cell transplantation (HSCT). A cohort of 44 consecutive pediatric patients who underwent HSCT was retrospectively analyzed to see the role of DFT on engraftment. Patients were assigned into two groups based on the use or non-use of prophylaxis with DFT. The mean time to engraftment was statistically different between the two groups for both polymorphonuclear neutrophils (PMN) and white blood cells. Our study supports the hypothesis that prophylaxis with DFT for VOD leads to a delay to the engraftment of PMN in pediatric patients that underwent HSCT.

  7. Defibrotide for the treatment of severe hepatic veno-occlusive disease and multiorgan failure after stem cell transplantation: a multicenter, randomized, dose-finding trial.

    PubMed

    Richardson, Paul G; Soiffer, Robert J; Antin, Joseph H; Uno, Hajime; Jin, Zhezhen; Kurtzberg, Joanne; Martin, Paul L; Steinbach, Gideon; Murray, Karen F; Vogelsang, Georgia B; Chen, Allen R; Krishnan, Amrita; Kernan, Nancy A; Avigan, David E; Spitzer, Thomas R; Shulman, Howard M; Di Salvo, Donald N; Revta, Carolyn; Warren, Diane; Momtaz, Parisa; Bradwin, Gary; Wei, L J; Iacobelli, Massimo; McDonald, George B; Guinan, Eva C

    2010-07-01

    Therapeutic options for severe hepatic veno-occlusive disease (VOD) are limited and outcomes are dismal, but early phase I/II studies have suggested promising activity and acceptable toxicity using the novel polydisperse oligonucleotide defibrotide. This randomized phase II dose-finding trial determined the efficacy of defibrotide in patients with severe VOD following hematopoietic stem cell transplantation (HSCT) and identified an appropriate dose for future trials. Adult and pediatric patients received either lower-dose (arm A: 25 mg/kg/day; n = 75) or higher-dose (arm B: 40 mg/kg/day; n = 74) i.v. defibrotide administered in divided doses every 6 hours for > or =14 days or until complete response, VOD progression, or any unacceptable toxicity occurred. Overall complete response and day +100 post-HSCT survival rates were 46% and 42%, respectively, with no significant difference between treatment arms. The incidence of treatment-related adverse events was low (8% overall; 7% in arm A, 10% in arm B); there was no significant difference in the overall rate of adverse events between treatment arms. Early stabilization or decreased bilirubin was associated with better response and day +100 survival, and decreased plasminogen activator inhibitor type 1 (PAI-1) during treatment was associated with better outcome; changes were similar in both treatment arms. Defibrotide 25 or 40 mg/kg/day also appears effective in treating severe VOD following HSCT. In the absence of any differences in activity, toxicity or changes in PAI-1 level, defibrotide 25 mg/kg/day was selected for ongoing phase III trials in VOD.

  8. Defibrotide: An Oligonucleotide for Sinusoidal Obstruction Syndrome.

    PubMed

    Aziz, May T; Kakadiya, Payal P; Kush, Samantha M; Weigel, Kylie; Lowe, Denise K

    2018-02-01

    To review the efficacy and safety of defibrotide as well as its pharmacology, mechanism of action, pharmacokinetics (PK), drug-drug interactions, dosing, cost considerations, and place in therapy. A PubMed search was performed through August 2017 using the terms defibrotide, oligonucleotide, hepatic veno-occlusive disease (VOD), sinusoidal obstruction syndrome (SOS), and hematopoietic cell transplantation (HCT). Other data sources were from references of identified studies, review articles, and conference abstracts plus manufacturer product labeling and website, the Food and Drug Administration website, and clinicaltrials.gov. English-language trials that examined defibrotide's pharmacodynamics, mechanism, PK, efficacy, safety, dosing, and cost-effectiveness were included. Trials have confirmed the safety and efficacy of defibrotide for treatment of VOD/SOS in adult and pediatric HCT patients, with complete response rates and day +100 overall survival rates ranging from 25.5% to 76% and 35% to 64%, respectively. The British Committee for Standards in Haematology/British Society for Blood and Marrow Transplantation Guidelines recommend defibrotide prophylaxis in pediatric and adult HCT patients with risk factors for VOD/SOS; however, its prophylactic use in the United States is controversial. Although there are efficacy data to support this strategy, cost-effectiveness data have not shown it to be cost-effective. Defibrotide has manageable toxicities, with low rates of grade 3 to 4 adverse effects. Defibrotide is the first medication approved in the United States for the treatment of adults and children with hepatic VOD/SOS, with renal or pulmonary dysfunction following HCT. Data evaluating defibrotide for VOD/SOS prevention are conflicting and have not shown cost-effectiveness.

  9. Final results from a defibrotide treatment-IND study for patients with hepatic veno-occlusive disease/sinusoidal obstruction syndrome.

    PubMed

    Kernan, Nancy A; Grupp, Stephan; Smith, Angela R; Arai, Sally; Triplett, Brandon; Antin, Joseph H; Lehmann, Leslie; Shore, Tsiporah; Ho, Vincent T; Bunin, Nancy; Iacobelli, Massimo; Liang, Wei; Hume, Robin; Tappe, William; Soiffer, Robert; Richardson, Paul

    2018-05-16

    Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of haematopoietic stem cell transplant (HSCT) conditioning and chemotherapy. Defibrotide is approved for treatment of hepatic VOD/SOS with pulmonary or renal dysfunction [i.e., multi-organ dysfunction (MOD)] after HSCT in the United States and severe VOD/SOS after HSCT in patients aged older than 1 month in the European Union. Defibrotide was available as an investigational drug by an expanded-access treatment programme (T-IND; NCT00628498). In the completed T-IND, the Kaplan-Meier estimated Day +100 survival for 1000 patients with documented defibrotide treatment after HSCT was 58·9% [95% confidence interval (CI), 55·7-61·9%]. Day +100 survival was also analysed by age and MOD status, and post hoc analyses were performed to determine Day +100 survival by transplant type, timing of VOD/SOS onset (≤21 or >21 days) and timing of defibrotide treatment initiation after VOD/SOS diagnosis. Day +100 survival in paediatric patients was 67·9% (95% CI, 63·8-71·6%) and 47·1% (95% CI, 42·3-51·8%) in adults. All patient subgroups without MOD had higher Day +100 survival than those with MOD; earlier defibrotide initiation was also associated with higher Day +100 survival. The safety profile of defibrotide in the completed T-IND study was similar to previous reports. © 2018 The Authors. British Journal of Haematology published by John Wiley & Sons Ltd.

  10. Land Surface Phenologies and Seasonalities of Croplands and Grasslands in the US Prairie Pothole Region Using Passive Microwave Data (2003-2015)

    NASA Astrophysics Data System (ADS)

    Alemu, W. G.; Henebry, G. M.

    2017-12-01

    Grasslands and wetlands in the Prairie Pothole Region (PPR) have been converted to croplands in recent years. Crops cultivated in the PPR are also changing: spring wheat and alfalfa/hay are being switched to corn and soybean due to biofuel demand. According to the USDA Cropland Data Layer (CDL) from 2003 to 2015, spring wheat significantly decreased (r2 = 0.74), while corn and soybeans significantly increased (r2 = 0.86). We characterized land surface phenologies and land surface seasonalities across the PPR using the finer temporal (twice daily) but much lower spatial (25 km) resolution Advanced Microwave Scanning Radiometer (AMSR: blended from AMSR-E and AMSR2) enhanced land surface parameters for 2003-2015 (DOY 91-330 annual cycles). We tracked the temporal development of these land surface parameters as a function of accumulated growing degree-days (AGDD) based on the AMSR retrieved air temperature data. Growing degree-days (GDD) revealed distinct seasonality typical to temperate grasslands and croplands. GDD peaks were 23°C and it peaks at 1700°C AGDD. Precipitable water vapor (V) displayed seasonality comparable to GDD. Vegetation optical depth (VOD) revealed distinct land surface phenologies for grasslands versus croplands. We explored the changing crop fractions within the 25 km AMSR pixels using the CDL. Crop-dominated sites VOD time series caught the early spring growth, ploughing, and crop growth dynamics. In contrast, the VOD time series at grass-dominated sites exhibited a lower but more extended amplitude throughout the non-frozen season. VODs peaked at 1.6 and 1.3 for croplands and grasslands, respectively. Croplands peaked about a month later than grasslands (2200 °C AGDD vs. 1600 °C AGDD). The other parameters available from the AMSR dataset—soil moisture (sm), and fractional open water (fw)—together with the AGDD time series constructed from the AMSR air temperature data revealed the passage of storm systems during the growing season. Soil moisture and fractional water were slightly higher in early spring compared to the main growing season; however, neither parameter exhibited distinct seasonality. VOD and fw time series curves displayed significant interannual variation that can enable to augment drought-monitoring efforts.

  11. Assessment of Vegetation Responses and Sensitivity to the Millennium Drought in Australia

    NASA Astrophysics Data System (ADS)

    Jiao, T.; Williams, C. A.

    2017-12-01

    During the period from 1997 to 2009, Australia experienced one of the most severe and persistent drought known as the Millennium Drought (MD). Major water shortages were reported across the Australian continent as well as a great many tree mortality during and post this drought event. Given the projection of hotter and drier conditions for much of the continent (Hughes 2003), it is critical to analyze the impacts of climate extremes like MD as an indicator of possible impacts of future trends. A few drought assessments have been performed for the MD but their utilization of single-source Remote sensing data like vegetation indices makes it difficult to produce a comprehensive understanding of drought responses for diverse ecosystems in Australia. Furthermore, methods adopted in past drought assessments did not distinguish vegetation responses to drought events with different intensity, duration and sequence, which are critically important in determining the magnitude of vegetation responses to drought. Here, multi-source remote sensing datasets and an event-based drought assessment method were employed to assess the impacts of MD on vegetation in Australia in terms of the magnitude and sensitivity. Vegetation variables examined include fraction of photosynthetically absorbed radiation (Fpar), vegetation optical depth (VOD) and aboveground biomass (AGB). Drought indicators were calculated based on precipitation and potential evapotranspiration. Results show that most of Eastern Australia experienced abnormal water deficit during the MD and drought intensity was greatest in humid regions. The decline in aboveground biomass (ABC) demonstrates consistent variation with drought intensity across aridity levels. Drought impacts on Fpar and VOD were greatest at intermediate dryness and for woodier ecosystems, with impacts appearing in Fpar before VOD. Drought sensitivity was also greatest at intermediate dryness and for woodier ecosystems. The small difference in drought sensitivity, in terms of Fpar and VOD, across biomes suggests that trees, shrubs, and herbaceous are equally vulnerable to canopy dieback while the high drought sensitivity of trees as shown in ABC implies that a large amount of carbon could be released to the atmosphere if intense and long-duration drought occurs in forested areas.

  12. Development of a clinical applicable graphical user interface to automatically detect exercise oscillatory ventilation: The VOdEX-tool.

    PubMed

    Cornelis, Justien; Denis, Tim; Beckers, Paul; Vrints, Christiaan; Vissers, Dirk; Goossens, Maggy

    2017-08-01

    Cardiopulmonary exercise testing (CPET) gained importance in the prognostic assessment of especially patients with heart failure (HF). A meaningful prognostic parameter for early mortality in HF is exercise oscillatory ventilation (EOV). This abnormal respiratory pattern is recognized by hypo- and hyperventilation during CPET. Up until now, assessment of EOV is mainly done upon visual agreement or manual calculation. The purpose of this research was to automate the interpretation of EOV so this prognostic parameter could be readily investigated during CPET. Preliminary, four definitions describing the original characteristics of EOV, were selected and integrated in the "Ventilatory Oscillations during Exercise-tool" (VOdEX-tool), a graphical user interface that allows automate calculation of EOV. A Discrete Meyer Level 2 wavelet transformation appeared to be the optimal filter to apply on the collected breath-by-breath minute ventilation CPET data. Divers aspects of the definitions i.e. cycle length, amplitude, regularity and total duration of EOV were combined and calculated. The oscillations meeting the criteria were visualised. Filter methods and cut-off criteria were made adjustable for clinical application and research. The VOdEX-tool was connected to a database. The VOdEX-tool provides the possibility to calculate EOV automatically and to present the clinician an overview of the presence of EOV at a glance. The computerized analysis of EOV can be made readily available in clinical practice by integrating the tool in the manufactures existing CPET software. The VOdEX-tool enhances assessment of EOV and therefore contributes to the estimation of prognosis in especially patients with HF. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Defibrotide for the Treatment of Severe Hepatic Veno-Occlusive Disease and Multiorgan Failure after Stem Cell Transplantation: A Multicenter, Randomized, Dose-Finding Trial

    PubMed Central

    Richardson, Paul G.; Soiffer, Robert J.; Antin, Joseph H.; Uno, Hajime; Jin, Zhezhen; Kurtzberg, Joanne; Martin, Paul L.; Steinbach, Gideon; Murray, Karen F.; Vogelsang, Georgia B.; Chen, Allen R.; Krishnan, Amrita; Kernan, Nancy A.; Avigan, David E.; Spitzer, Thomas R.; Shulman, Howard M.; Di Salvo, Donald N.; Revta, Carolyn; Warren, Diane; Momtaz, Parisa; Bradwin, Gary; Wei, L. J.; Iacobelli, Massimo; McDonald, George B.; Guinan, Eva C.

    2010-01-01

    Therapeutic options for severe hepatic veno-occlusive disease (VOD) are limited and outcomes are dismal, but early phase I/II studies have suggested promising activity and acceptable toxicity using the novel polydisperse oligonucleotide defibrotide. This randomized phase II dose-finding trial determined the efficacy of defibrotide in patients with severe VOD following hematopoietic stem cell transplantation (HSCT) and identified an appropriate dose for future trials. Adult and pediatric patients received either lower-dose (arm A: 25 mg/kg/day; n = 75) or higher-dose (arm B: 40 mg/kg/day; n = 74) i.v. defibrotide administered in divided doses every 6 hours for ≥ 14 days or until complete response, VOD progression, or any unacceptable toxicity occurred. Overall complete response and day + 100 post-HSCT survival rates were 46% and 42%, respectively, with no significant difference between treatment arms. The incidence of treatment-related adverse events was low (8% overall; 7% in arm A, 10% in arm B); there was no significant difference in the overall rate of adverse events between treatment arms. Early stabilization or decreased bilirubin was associated with better response and day + 100 survival, and decreased plasminogen activator inhibitor type 1 (PAI-1) during treatment was associated with better outcome; changes were similar in both treatment arms. Defibrotide 25 or 40 mg/kg/day also appears effective in treating severe VOD following HSCT. In the absence of any differences in activity, toxicity or changes in PAI-1 level, defibrotide 25 mg/kg/day was selected for ongoing phase III trials in VOD. PMID:20167278

  14. On the Design of the Peer-Assisted UGC VoD System

    NASA Astrophysics Data System (ADS)

    Wan, Yi; Asaka, Takuya; Takahashi, Tatsuro

    User Generated Content (UGC) VoD services such as YouTube are becoming more and more popular, and their maintenance costs are growing as well. Many P2P solutions have been proposed to reduce server load in such systems, but almost all of them focus on the single-video approach, which only has limited effect on the systems serving short videos such as UGC. The purpose of this paper is to investigate the potential of an alternative approach, the multi-video approach, and we use a very simple method called collaborative caching to show that methods using the multi-video approach are generally more suitable for current UGC VoD systems. We also study the influence of the major design factors through simulations and provide guidelines for efficiently building systems with this method.

  15. Assessment of Wildfire Risk in Southern California with Live Fuel Moisture Measurement and Remotely Sensed Vegetation Water Content Proxies

    NASA Astrophysics Data System (ADS)

    Jia, S.; Kim, S. H.; Nghiem, S. V.; Kafatos, M.

    2017-12-01

    Live fuel moisture (LFM) is the water content of live herbaceous plants expressed as a percentage of the oven-dry weight of plant. It is a critical parameter in fire ignition in Mediterranean climate and routinely measured in sites selected by fire agencies across the U.S. Vegetation growing cycle, meteorological metrics, soil type, and topography all contribute to the seasonal and inter-annual variation of LFM, and therefore, the risk of wildfire. The optical remote sensing-based vegetation indices (VIs) have been used to estimate the LFM. Comparing to the VIs, microwave remote sensing products have advantages like less saturation effect in greenness and representing the water content of the vegetation cover. In this study, we established three models to evaluate the predictability of LFM in Southern California using MODIS NDVI, vegetation temperature condition index (VTCI) from downscaled Soil Moisture Active Passive (SMAP) products, and vegetation optical depth (VOD) derived by Land Parameter Retrieval Model. Other ancillary variables, such as topographic factors (aspects and slope) and meteorological metrics (air temperature, precipitation, and relative humidity), are also considered in the models. The model results revealed an improvement of LFM estimation from SMAP products and VOD, despite the uncertainties introduced in the downscaling and parameter retrieval. The estimation of LFM using remote sensing data can provide an assessment of wildfire danger better than current methods using NDVI-based growing seasonal index. Future study will test the VOD estimation from SMAP data using the multi-temporal dual channel algorithm (MT-DCA) and extend the LFM modeling to a regional scale.

  16. Probabilistic Seeking Prediction in P2P VoD Systems

    NASA Astrophysics Data System (ADS)

    Wang, Weiwei; Xu, Tianyin; Gao, Yang; Lu, Sanglu

    In P2P VoD streaming systems, user behavior modeling is critical to help optimise user experience as well as system throughput. However, it still remains a challenging task due to the dynamic characteristics of user viewing behavior. In this paper, we consider the problem of user seeking prediction which is to predict the user's next seeking position so that the system can proactively make response. We present a novel method for solving this problem. In our method, frequent sequential patterns mining is first performed to extract abstract states which are not overlapped and cover the whole video file altogether. After mapping the raw training dataset to state transitions according to the abstract states, we use a simpel probabilistic contingency table to build the prediction model. We design an experiment on the synthetic P2P VoD dataset. The results demonstrate the effectiveness of our method.

  17. A Scalable QoS-Aware VoD Resource Sharing Scheme for Next Generation Networks

    NASA Astrophysics Data System (ADS)

    Huang, Chenn-Jung; Luo, Yun-Cheng; Chen, Chun-Hua; Hu, Kai-Wen

    In network-aware concept, applications are aware of network conditions and are adaptable to the varying environment to achieve acceptable and predictable performance. In this work, a solution for video on demand service that integrates wireless and wired networks by using the network aware concepts is proposed to reduce the blocking probability and dropping probability of mobile requests. Fuzzy logic inference system is employed to select appropriate cache relay nodes to cache published video streams and distribute them to different peers through service oriented architecture (SOA). SIP-based control protocol and IMS standard are adopted to ensure the possibility of heterogeneous communication and provide a framework for delivering real-time multimedia services over an IP-based network to ensure interoperability, roaming, and end-to-end session management. The experimental results demonstrate that effectiveness and practicability of the proposed work.

  18. Application of Liquid Paraffin in Castable CL-20-Based PBX

    NASA Astrophysics Data System (ADS)

    Zhang, Pu; Guo, Xue-Yong; Zhang, Jing-Yuan; Jiao, Qing-Jie

    2014-10-01

    Hydroxy-terminated polybutadiene (HTPB)/CL-20 castable explosives plasticized with liquid paraffin were processed successfully by a cast-curing method. The compatibility of liquid paraffin with CL-20, influence of liquid paraffin on CL-20 phase transition, and viscosity of the cast mixture were tested and analyzed. The thermal decomposition characteristics, thermal stability, mechanical sensitivity, and velocity of detonation (VOD) of the HTPB/CL-20 plastic-bonded explosives (PBXs) were also measured. The experimental results showed that liquid paraffin was well compatible with CL-20, and it did not have a distinct effect on the ɛ- to γ-phase transition of CL-20. In addition, the casting mixture was free-flowing with sufficiently low viscosity. When the content of CL-20 is 90% by weight, the measured VOD reached 8,775 m/s (density of 1.78 g/cm3), and the PBXs exhibited moderate mechanical sensitivity and good thermal stability.

  19. Estimating Global Ecosystem Isohydry/Anisohydry Using Active and Passive Microwave Satellite Data

    NASA Astrophysics Data System (ADS)

    Li, Yan; Guan, Kaiyu; Gentine, Pierre; Konings, Alexandra G.; Meinzer, Frederick C.; Kimball, John S.; Xu, Xiangtao; Anderegg, William R. L.; McDowell, Nate G.; Martinez-Vilalta, Jordi; Long, David G.; Good, Stephen P.

    2017-12-01

    The concept of isohydry/anisohydry describes the degree to which plants regulate their water status, operating from isohydric with strict regulation to anisohydric with less regulation. Though some species level measures of isohydry/anisohydry exist at a few locations, ecosystem-scale information is still largely unavailable. In this study, we use diurnal observations from active (Ku-Band backscatter from QuikSCAT) and passive (X-band vegetation optical depth (VOD) from Advanced Microwave Scanning Radiometer on EOS Aqua) microwave satellite data to estimate global ecosystem isohydry/anisohydry. Here diurnal observations from both satellites approximate predawn and midday plant canopy water contents, which are used to estimate isohydry/anisohydry. The two independent estimates from radar backscatter and VOD show reasonable agreement at low and middle latitudes but diverge at high latitudes. Grasslands, croplands, wetlands, and open shrublands are more anisohydric, whereas evergreen broadleaf and deciduous broadleaf forests are more isohydric. The direct validation with upscaled in situ species isohydry/anisohydry estimates indicates that the VOD-based estimates have much better agreement than the backscatter-based estimates. The indirect validation with prior knowledge suggests that both estimates are generally consistent in that vegetation water status of anisohydric ecosystems more closely tracks environmental fluctuations of water availability and demand than their isohydric counterparts. However, uncertainties still exist in the isohydry/anisohydry estimate, primarily arising from the remote sensing data and, to a lesser extent, from the methodology. The comprehensive assessment in this study can help us better understand the robustness, limitation, and uncertainties of the satellite-derived isohydry/anisohydry estimates. The ecosystem isohydry/anisohydry has the potential to reveal new insights into spatiotemporal ecosystem response to droughts.

  20. Sorption of phenanthrene and benzene on differently structural kerogen: important role of micropore-filling.

    PubMed

    Zhang, Yulong; Ma, Xiaoxuan; Ran, Yong

    2014-02-01

    Shale was thermally treated to obtain a series of kerogen with varied maturation. Their chemical, structural and porous properties were related to the sorption and/or desorption behaviors of phenanthrene and benzene. As the treatment temperature increases, aliphatic and carbonyl carbon of the kerogen samples decrease, while their aromaticity and maturation increase. Meanwhile, the isothermal nonlinearity of phenanthrene and benzene increases whereas the sorption capacity and micropore adsorption volumes (Vo,d) initially increase and then decrease. The Vo,d of benzene is significantly correlated with, but higher than that of phenanthrene, suggesting similar micropore filling mechanism and molecular sieve effect. The benzene desorption exhibits hysteresis, which is related to the pore deformation of the kerogen and the entrapment of solute in the kerogen matrix. The Vo,d of phenanthrene and benzene on the kerogen samples accounts for 23-46% and 36-65% of the maximum sorption volumes, respectively, displaying the importance of the micropore filling. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Integration of satellite-induced fluorescence and vegetation optical depth to improve the retrieval of land evaporation

    NASA Astrophysics Data System (ADS)

    Pagán, B. R.; Martens, B.; Maes, W. H.; Miralles, D. G.

    2017-12-01

    Global satellite-based data sets of land evaporation overcome limitations in coverage of in situ measurements while retaining some observational nature. Although their potential for real world applications are promising, their value during dry conditions is still poorly understood. Most evaporation retrieval algorithms are not directly sensitive to soil moisture. An exception is the Global Land Evaporation Amsterdam Model (GLEAM), which uses satellite surface soil moisture and precipitation to account for land water availability. The existing methodology may greatly benefit from the optimal integration of novel observations of the land surface. Microwave vegetation optical depth (VOD) and near-infrared solar-induced fluorescence (SIF) are expected to reflect different aspects of evaporative stress. While the former is considered to be a proxy of vegetation water content, the latter is indicative of the activity of photosynthetic machinery. As stomata regulate both photosynthesis and transpiration, we expect a relationship between SIF and transpiration. An important motivation to incorporate observations in land evaporation calculations is that plant transpiration - usually the largest component of the flux - is extremely challenging to model due to species-dependent responses to drought. Here we present an innovative integration of VOD and SIF into the GLEAM evaporative stress function. VOD is utilized as a measurement of isohydricity to improve the representation of species specific drought responses. SIF is used for transpiration modelling, a novel application, and standardized by incoming solar radiation to better account for radiation-limited periods. Results are validated with global FLUXNET and International Soil Moisture Network data and demonstrate that the incorporation of VOD and SIF can yield accurate estimates of transpiration over large-scales, which are essential to further understand ecosystem-atmosphere feedbacks and the response of terrestrial hydrology and ecology to meteorological drought. The resulting retrievals of land evaporation can be used to benchmark climate model representation of turbulent fluxes, at a time when these models still consider water stress rudimentarily, and typically assume the same sensitivity for all vegetation types to drought stress.

  2. Transfusional iron burden and liver toxicity after bone marrow transplantation for acute myelogenous leukemia and hemoglobinopathies.

    PubMed

    Jastaniah, Wasil; Harmatz, Paul; Pakbaz, Zahra; Fischer, Roland; Vichinsky, Elliott; Walters, Mark C

    2008-02-01

    While it is appropriate to treat transfusional iron overload to limit end-organ injury after bone marrow transplantation (BMT) for beta-thalassemia major (TM), this approach after BMT for sickle cell disease (SCD) and hematological malignancies has not been studied. Fifteen children with SCD (n = 4), TM (n = 6), or acute myelogenous leukemia (AML, n = 5) underwent HLA-identical sibling BMT between 2000 and 2003. Prospective evaluations of iron biomarkers were performed and the three groups were compared. The pre-BMT duration and volume of RBC transfusions varied among the three groups, but baseline ferritin and liver iron concentration (LIC) were similar. In contrast, liver histology differed. Liver inflammation was present in four TM patients and portal fibrosis was observed in five TM and one SCD patient. Hepatic veno-occlusive disease (VOD) developed in 5 of 15 patients. VOD was not associated with age, ferritin, ALT, or transfusions, but an association with liver inflammation and elevated LIC was suggested. Phlebotomy was performed in five patients after BMT. Changes in LIC were minimal in non-phlebotomized patients (P = 0.02). Iron biomarkers demonstrated significant iron overload before BMT in patients with malignant and non-malignant disorders. However, iron overload was associated with liver inflammation and VOD primarily in TM patients. The clinical significance of iron overload in patients after BMT remains uncertain, but this is the first study to suggest that VOD may be associated with transfusional iron burden. (c) 2007 Wiley-Liss, Inc.

  3. Global-scale assessment and combination of SMAP with ASCAT (active) and AMSR2 (passive) soil moisture products

    NASA Astrophysics Data System (ADS)

    Kim, Hyunglok; Parinussa, Robert; Konings, Alexandra G.; Wagner, Wolfgang; Cosh, Michael H.; Lakshmi, Venkat; Zohaib, Muhammad; Choi, Minha

    2018-01-01

    Global-scale surface soil moisture (SSM) products retrieved from active and passive microwave remote sensing provide an effective method for monitoring near-real-time SSM content with nearly daily temporal resolution. In the present study, we first inter-compared global-scale error patterns and combined the Soil Moisture Active Passive (SMAP), Advanced Scatterometer (ASCAT), and Advanced Microwave Scanning Radiometer 2 (AMSR2) SSM products using a triple collocation (TC) analysis and the maximized Pearson correlation coefficient (R) method from April 2015 to December 2016. The Global Land Data Assimilation System (GLDAS) and global in situ observations were utilized to investigate and to compare the quality of satellite-based SSM products. The average R-values of SMAP, ASCAT, and AMSR2 were 0.74, 0.64, and 0.65 when they compared with in situ networks, respectively. The ubRMSD values were (0.0411, 0.0625, and 0.0708) m3 m- 3; and the bias values were (- 0.0460, 0.0010, and 0.0418) m3 m- 3 for SMAP, ASCAT, and AMSR2, respectively. The highest average R-values from SMAP against the in situ results are very encouraging; only SMAP showed higher R-values than GLDAS in several in situ networks with low ubRMSD (0.0438 m3 m- 3). Overall, SMAP showed a dry bias (- 0.0460 m3 m- 3) and AMSR2 had a wet bias (0.0418 m3 m- 3); while ASCAT showed the least bias (0.0010 m3 m- 3) among all the products. Each product was evaluated using TC metrics with respect to the different ranges of vegetation optical depth (VOD). Under vegetation scarce conditions (VOD < 0.10), such as desert and semi-desert regions, all products have difficulty obtaining SSM information. In regions with moderately vegetated areas (0.10 < VOD < 0.40), SMAP showed the highest Signal-to-Noise Ratio. Over highly vegetated regions (VOD > 0.40) ASCAT showed comparatively better performance than did the other products. Using the maximized R method, SMAP, ASCAT, and AMSR2 products were combined one by one using the GLDAS dataset for reference SSM values. When the satellite products were combined, R-values of the combined products were improved or degraded depending on the VOD ranges produced, when compared with the results from the original products alone. The results of this study provide an overview of SMAP, ASCAT, and AMSR2 reliability and the performance of their combined products on a global scale. This study is the first to show the advantages of the recently available SMAP dataset for effective merging of different satellite products and of their application to various hydro-meteorological problems.

  4. Consensus Report by the Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplant Consortium Joint Working Committees on Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents: Part 2-Focus on Ascites, Fluid and Electrolytes, Renal, and Transfusion Issues.

    PubMed

    Mahadeo, Kris M; McArthur, Jennifer; Adams, Roberta H; Radhi, Mohamed; Angelo, Joseph; Jeyapalan, Asumthia; Nicol, Kathleen; Su, Leon; Rabi, Hanna; Auletta, Jeffery J; Pai, Vinita; Duncan, Christine N; Tamburro, Robert; Dvorak, Christopher C; Bajwa, Rajinder P S

    2017-12-01

    Even though hepatic veno-occlusive disease (VOD) is a potentially fatal complication of hematopoietic cell transplantation (HCT), there is paucity of research on the management of associated multiorgan dysfunction. To help provide standardized care for the management of these patients, the HCT Subgroup of the Pediatric Acute Lung Injury and Sepsis Investigators and the Supportive Care Committee of the Pediatric Blood and Marrow Transplant Consortium, collaborated to develop evidence-based consensus guidelines. After conducting an extensive literature search, in part 2 of this series we discuss the management of fluids and electrolytes, renal dysfunction; ascites, pleural effusion, and transfusion and coagulopathy issues in patients with VOD. We consider the available evidence using the GRADE criteria. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  5. Design issues and caching strategies for CD-ROM-based multimedia storage

    NASA Astrophysics Data System (ADS)

    Shastri, Vijnan; Rajaraman, V.; Jamadagni, H. S.; Venkat-Rangan, P.; Sampath-Kumar, Srihari

    1996-03-01

    CD-ROMs have proliferated as a distribution media for desktop machines for a large variety of multimedia applications (targeted for a single-user environment) like encyclopedias, magazines and games. With CD-ROM capacities up to 3 GB being available in the near future, they will form an integral part of Video on Demand (VoD) servers to store full-length movies and multimedia. In the first section of this paper we look at issues related to the single- user desktop environment. Since these multimedia applications are highly interactive in nature, we take a pragmatic approach, and have made a detailed study of the multimedia application behavior in terms of the I/O request patterns generated to the CD-ROM subsystem by tracing these patterns. We discuss prefetch buffer design and seek time characteristics in the context of the analysis of these traces. We also propose an adaptive main-memory hosted cache that receives caching hints from the application to reduce the latency when the user moves from one node of the hyper graph to another. In the second section we look at the use of CD-ROM in a VoD server and discuss the problem of scheduling multiple request streams and buffer management in this scenario. We adapt the C-SCAN (Circular SCAN) algorithm to suit the CD-ROM drive characteristics and prove that it is optimal in terms of buffer size management. We provide computationally inexpensive relations by which this algorithm can be implemented. We then propose an admission control algorithm which admits new request streams without disrupting the continuity of playback of the previous request streams. The algorithm also supports operations such as fast forward and replay. Finally, we discuss the problem of optimal placement of MPEG streams on CD-ROMs in the third section.

  6. The budget impact and cost-effectiveness of defibrotide for treatment of veno-occlusive disease with multi-organ dysfunction in patients post-hematopoietic stem cell transplant.

    PubMed

    Veenstra, David L; Guzauskas, Gregory F; Villa, Kathleen F; Boudreau, Denise M

    2017-05-01

    A Phase-3 study of defibrotide compared with historical controls demonstrated a 23% improvement in 100-day survival post-hematopoietic stem cell transplantation (HSCT) among patients with veno-occlusive disease with multi-organ dysfunction (VOD with MOD). To estimate the budget impact and cost-effectiveness of introducing defibrotide to a transplant center. The authors developed a budget impact model from the perspective of a bone-marrow transplant center. It was estimated that 2.3% of adults and 4.2% of children would develop VOD with MOD following HSCT based on a retrospective hospital database analysis and the effect that treating patients with defibrotide would have on costs for adult and pediatric centers was estimated. A cost-utility analysis (CUA) was also developed to capture the long-term cost-effectiveness of defibrotide. Projected life expectancies in the two groups were estimated based on trial data, transplant registry data, studies of long-term survival among HSCT patients, and US population life-tables. There was an estimated 3% increase ($330,706) per year in total adult transplantation center costs associated with adopting defibrotide, and a <1% increase ($106,385) for pediatric transplant centers, assuming 100 transplants per year. In the CUA, the lifetime increase in cost per patient was $106,928, life expectancy increased by 3.74 years, and quality-adjusted life-years (QALYs) increased by 2.24. The incremental cost-effectiveness ratio (ICER) was $47,736 per QALY gained; 88% probability defibrotide was cost-effective at a $100,000/QALY threshold. The budget impact of defibrotide for a transplant center is relatively modest compared to the overall cost of transplantation. Defibrotide provides an important survival advantage for VOD with MOD patients, and the life years gained lead to defibrotide being highly cost-effective.

  7. Phase 3 trial of defibrotide for the treatment of severe veno-occlusive disease and multi-organ failure

    PubMed Central

    Riches, Marcie L.; Kernan, Nancy A.; Brochstein, Joel A.; Mineishi, Shin; Termuhlen, Amanda M.; Arai, Sally; Grupp, Stephan A.; Guinan, Eva C.; Martin, Paul L.; Steinbach, Gideon; Krishnan, Amrita; Nemecek, Eneida R.; Giralt, Sergio; Rodriguez, Tulio; Duerst, Reggie; Doyle, John; Antin, Joseph H.; Smith, Angela; Lehmann, Leslie; Champlin, Richard; Gillio, Alfred; Bajwa, Rajinder; D’Agostino, Ralph B.; Massaro, Joseph; Warren, Diane; Miloslavsky, Maja; Hume, Robin L.; Iacobelli, Massimo; Nejadnik, Bijan; Hannah, Alison L.; Soiffer, Robert J.

    2016-01-01

    Hepatic veno-occlusive disease (VOD), also called sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). Untreated hepatic VOD/SOS with multi-organ failure (MOF) is associated with >80% mortality. Defibrotide has shown promising efficacy treating hepatic VOD/SOS with MOF in phase 2 studies. This phase 3 study investigated safety and efficacy of defibrotide in patients with established hepatic VOD/SOS and advanced MOF. Patients (n = 102) given defibrotide 25 mg/kg per day were compared with 32 historical controls identified out of 6867 medical charts of HSCT patients by blinded independent reviewers. Baseline characteristics between groups were well balanced. The primary endpoint was survival at day +100 post-HSCT; observed rates equaled 38.2% in the defibrotide group and 25% in the controls (23% estimated difference; 95.1% confidence interval [CI], 5.2-40.8; P = .0109, using a propensity-adjusted analysis). Observed day +100 complete response (CR) rates equaled 25.5% for defibrotide and 12.5% for controls (19% difference using similar methodology; 95.1% CI, 3.5-34.6; P = .0160). Defibrotide was generally well tolerated with manageable toxicity. Related adverse events (AEs) included hemorrhage or hypotension; incidence of common hemorrhagic AEs (including pulmonary alveolar [11.8% and 15.6%] and gastrointestinal bleeding [7.8% and 9.4%]) was similar between the defibrotide and control groups, respectively. Defibrotide was associated with significant improvement in day +100 survival and CR rate. The historical-control methodology offers a novel, meaningful approach for phase 3 evaluation of orphan diseases associated with high mortality. This trial was registered at www.clinicaltrials.gov as #NCT00358501. PMID:26825712

  8. Vegetation optical depth measured by microwave radiometry as an indicator of tree mortality risk

    NASA Astrophysics Data System (ADS)

    Rao, K.; Anderegg, W.; Sala, A.; Martínez-Vilalta, J.; Konings, A. G.

    2017-12-01

    Increased drought-related tree mortality has been observed across several regions in recent years. Vast spatial extent and high temporal variability makes field monitoring of tree mortality cumbersome and expensive. With global coverage and high temporal revisit, satellite remote sensing offers an unprecedented tool to monitor terrestrial ecosystems and identify areas at risk of large drought-driven tree mortality events. To date, studies that use remote sensing data to monitor tree mortality have focused on external climatic thresholds such as temperature and evapotranspiration. However, this approach fails to consider internal water stress in vegetation - which can vary across trees even for similar climatic conditions due to differences in hydraulic behavior, soil type, etc - and may therefore be a poor basis for measuring mortality events. There is a consensus that xylem hydraulic failure often precedes drought-induced mortality, suggesting depleted canopy water content shortly before onset of mortality. Observations of vegetation optical depth (VOD) derived from passive microwave are proportional to canopy water content. In this study, we propose to use variations in VOD as an indicator of potential tree mortality. Since VOD accounts for intrinsic water stress undergone by vegetation, it is expected to be more accurate than external climatic stress indicators. Analysis of tree mortality events in California, USA observed by airborne detection shows a consistent relationship between mortality and the proposed VOD metric. Although this approach is limited by the kilometer-scale resolution of passive microwave radiometry, our results nevertheless demonstrate that microwave-derived estimates of vegetation water content can be used to study drought-driven tree mortality, and may be a valuable tool for mortality predictions if they can be combined with higher-resolution variables.

  9. Phase 3 trial of defibrotide for the treatment of severe veno-occlusive disease and multi-organ failure.

    PubMed

    Richardson, Paul G; Riches, Marcie L; Kernan, Nancy A; Brochstein, Joel A; Mineishi, Shin; Termuhlen, Amanda M; Arai, Sally; Grupp, Stephan A; Guinan, Eva C; Martin, Paul L; Steinbach, Gideon; Krishnan, Amrita; Nemecek, Eneida R; Giralt, Sergio; Rodriguez, Tulio; Duerst, Reggie; Doyle, John; Antin, Joseph H; Smith, Angela; Lehmann, Leslie; Champlin, Richard; Gillio, Alfred; Bajwa, Rajinder; D'Agostino, Ralph B; Massaro, Joseph; Warren, Diane; Miloslavsky, Maja; Hume, Robin L; Iacobelli, Massimo; Nejadnik, Bijan; Hannah, Alison L; Soiffer, Robert J

    2016-03-31

    Hepatic veno-occlusive disease (VOD), also called sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). Untreated hepatic VOD/SOS with multi-organ failure (MOF) is associated with >80% mortality. Defibrotide has shown promising efficacy treating hepatic VOD/SOS with MOF in phase 2 studies. This phase 3 study investigated safety and efficacy of defibrotide in patients with established hepatic VOD/SOS and advanced MOF. Patients (n = 102) given defibrotide 25 mg/kg per day were compared with 32 historical controls identified out of 6867 medical charts of HSCT patients by blinded independent reviewers. Baseline characteristics between groups were well balanced. The primary endpoint was survival at day +100 post-HSCT; observed rates equaled 38.2% in the defibrotide group and 25% in the controls (23% estimated difference; 95.1% confidence interval [CI], 5.2-40.8;P= .0109, using a propensity-adjusted analysis). Observed day +100 complete response (CR) rates equaled 25.5% for defibrotide and 12.5% for controls (19% difference using similar methodology; 95.1% CI, 3.5-34.6;P= .0160). Defibrotide was generally well tolerated with manageable toxicity. Related adverse events (AEs) included hemorrhage or hypotension; incidence of common hemorrhagic AEs (including pulmonary alveolar [11.8% and 15.6%] and gastrointestinal bleeding [7.8% and 9.4%]) was similar between the defibrotide and control groups, respectively. Defibrotide was associated with significant improvement in day +100 survival and CR rate. The historical-control methodology offers a novel, meaningful approach for phase 3 evaluation of orphan diseases associated with high mortality. This trial was registered at www.clinicaltrials.gov as #. © 2016 by The American Society of Hematology.

  10. Veno occlusive disease: Update on clinical management

    PubMed Central

    Senzolo, M; Germani, G; Cholongitas, E; Burra, P; Burroughs, AK

    2007-01-01

    Hepatic veno-occlusive disease is a clinical syndrome characterized by hepatomegaly, ascites, weight gain and jaundice, due to sinusoidal congestion which can be caused by alkaloid ingestion, but the most frequent cause is haematopoietic stem cell transplantation (STC) and is also seen after solid organ transplantation. The incidence of veno occlusive disease (VOD) after STC ranges from 0 to 70%, but is decreasing. Survival is good when VOD is a mild form, but when it is severe and associated with an increase of hepatic venous pressure gradient > 20 mmHg, and mortality is about 90%. Prevention remains the best therapeutic strategy, by using non-myeloablative conditioning regimens before STC. Prophylactic administration of ursodeoxycholic acid, being an antioxidant and antiapoptotic agent, can have some benefit in reducing overall mortality. Defibrotide, which has pro-fibrinolytic and antithrombotic properties, is the most effective therapy; decompression of the sinusoids by a transjugular intrahepatic portosystemic shunt (TIPS) can be tried, especially to treat VOD after liver transplantation and when multiorgan failure (MOF) is not present. Liver transplantation can be the last option, but can not be considered a standard rescue therapy, because usually the concomitant presence of multiorgan failure contraindicates this procedure. PMID:17663504

  11. Comparative structural analysis of cytidine, ethenocytidine and their protonated salts. II. IR spectral studies.

    PubMed Central

    Krzyzosiak, W; Jaskólski, M; Sierzputowska-Gracz, H; Wiewiórowski, M

    1982-01-01

    The IR spectra of crystalline cytidine (Cyd), ethenocytidine (epsilon Cyd), and their hydrochlorides (Cyd-Hcl and epsilon CyD-HCl) have been analyzed to determine the spectroscopic manifestations of the structural differences that were previously established for these nucleosides from X-ray studies. O,N-Deuteration of the samples turned out to be a successful approach to obtaining interpretable spectra. The analysis was carried out in three frequency ranges: (i) The 2600-1900 cm-1 range originating from the vO-D and VN-D vibrations. All intermolecular hydrogen bonds could be recognized here. The positions of the individual vO-D (vN-D) bands were correlated with the geometrical delta HB parameters presenting the strengths of hydrogen bonds in which these groups act as donors (ii) The 1750-1500 cm-1 region originating from the stretching vibrations of double bonds. All absorption bands in this region were interpreted in terms of electronic structures of the base fragments. (iii) The region of the C-H stretching vibrations of the base fragments (3200-3000 cm-1) and sugar moieties (3000-2800 cm-1). The Csp2-H vibrations also reflect the electronic structures of the base fragments, whereas the vCsp-H frequencies seem to be sensitive to etheno-bridging and to the presence of an intramolecular C6-H...05' hydrogen bond. PMID:7079184

  12. Phreatic activity and hydrothermal alteration in the Valley of Desolation, Dominica, Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Mayer, Klaus; Scheu, Bettina; Yilmaz, Tim I.; Montanaro, Cristian; Albert Gilg, H.; Rott, Stefanie; Joseph, Erouscilla P.; Dingwell, Donald B.

    2017-12-01

    Phreatic eruptions are possibly the most dramatic surface expressions of hydrothermal activity, and they remain poorly understood. The near absence of precursory signals makes phreatic eruptions unpredictable with respect to both time and magnitude. The Valley of Desolation (VoD), Dominica, located close to the Boiling Lake, the second largest high-temperature volcanic crater lake in the world, hosts vigorous hydrothermal activity with hot springs, mud pools, fumaroles, and steaming ground. A phreatic or phreatomagmatic eruption from this site is considered to be the most likely scenario for future volcanic activity on Dominica. Yet there is little information regarding the trigger mechanisms and eruption processes of explosive events at this active hydrothermal center, and only a very small number of studies have investigated hydrothermal activity in the VoD. We therefore conducted two field campaigns in the VoD to map hydrothermal activity and its surficial phenomena. We also investigated alteration processes and their effects on degassing and phreatic eruption processes. We collected in situ petrophysical properties of clay-rich unconsolidated samples, and together with consolidated rock samples, we investigated the range of supergene and hydrothermal alteration in the laboratory. In addition, we performed rapid decompression experiments on unconsolidated soil samples. Our results show that alteration leads to an increasing abundance of clay minerals and a decrease in both strength and permeability of the rocks. In the immediate vicinity of degassing acid-sulfate fluids, advanced argillic alteration yields a mineral zoning which is influenced by meteoric water. The water-saturated basal zone is dominated by kaolinite run 0whereas alunite formation is favored at and above the groundwater table where atmospheric oxidation of H2S to H2SO4 occurs (e.g., steam-heated alteration). Alteration effects may in turn inhibit degassing at the surface, increasing the potential for pressurization in the subsurface and thus lead to phreatic eruptions. Rapid decompression experiments, together with ballistic trajectory calculations, constrain estimates of the conditions prior to the 1997 small-scale phreatic event in the VoD. The results presented here may serve as a contribution to the understanding of the hazard potential of ongoing hydrothermal activity within the VoD. On a broader perspective, our results will help evaluate hydrothermal activity in similar areas worldwide which might also have the potential for phreatic eruptions, for instance Poas (Costa Rica) or Tongariro and Waimangu (New Zealand).

  13. Defibrotide in the treatment of hepatic veno-occlusive disease

    PubMed Central

    Fulgenzi, Alessandro; Ferrero, Maria Elena

    2016-01-01

    Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), represents the most frequent complication in patients in early phase following hematopoietic stem-cell transplantation (HSCT). In its severe form, VOD/SOS can be associated with multiorgan failure and with a mortality rate >80% by day +100. Defibrotide (DF) (a mixture of 90% single-stranded phosphodiester oligonucleotides and 10% double-stranded phosphodiester oligonucleotides derived from controlled depolarization of porcine intestinal mucosal DNA) has been proposed for the treatment of SOS due to its ability to restore thrombo-fibrinolytic balance and protect endothelial cells. The present review highlights why the mechanisms of action of DF allow its successful use in the prevention and treatment of SOS following HSCT. PMID:27843363

  14. Defibrotide in the treatment of hepatic veno-occlusive disease.

    PubMed

    Fulgenzi, Alessandro; Ferrero, Maria Elena

    2016-01-01

    Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), represents the most frequent complication in patients in early phase following hematopoietic stem-cell transplantation (HSCT). In its severe form, VOD/SOS can be associated with multiorgan failure and with a mortality rate >80% by day +100. Defibrotide (DF) (a mixture of 90% single-stranded phosphodiester oligonucleotides and 10% double-stranded phosphodiester oligonucleotides derived from controlled depolarization of porcine intestinal mucosal DNA) has been proposed for the treatment of SOS due to its ability to restore thrombo-fibrinolytic balance and protect endothelial cells. The present review highlights why the mechanisms of action of DF allow its successful use in the prevention and treatment of SOS following HSCT.

  15. Ambulatory Patient Groups. An Evaluation for Military Health Care Use

    DTIC Science & Technology

    1993-01-01

    ELECTE UEC 14 W3 HR 93-004. November 1993 Tisdcmn ha~s boan a2ppio~vod i ý zelease a~nd Sale; its UNITED STATES ARMY MEDICAL DEPARTMENT CENTER AND...to allocate resources based on a diagnosis related groups type system, a team of researchers from the U.S. Army Medical Department Center and School...patient visits recorded from six Army Medical Treatment Facilities (MTFs). The MTFs were selected for their diverse missions and populations constituting a

  16. Pharmacokinetic profile of defibrotide in patients with renal impairment.

    PubMed

    Tocchetti, Paola; Tudone, Elena; Marier, Jean-Francois; Marbury, Thomas C; Zomorodi, Katie; Eller, Mark

    2016-01-01

    Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is an unpredictable, potentially life-threatening complication of hematopoietic stem cell transplant conditioning. Severe VOD/SOS, generally associated with multiorgan dysfunction (pulmonary or renal dysfunction), may be associated with >80% mortality. Defibrotide, recently approved in the US, has demonstrated efficacy treating hepatic VOD/SOS with multiorgan dysfunction. Because renal impairment is prevalent in patients with VOD/SOS, this Phase I, open-label, two-part study in adults examined the effects of hemodialysis and severe or end-stage renal disease (ESRD) on defibrotide pharmacokinetics (PK). Part 1 compared defibrotide PK during single 6.25 mg/kg doses infused with and without dialysis. Part 2 assessed defibrotide plasma PK after multiple 6.25 mg/kg doses in nondialysis-dependent subjects with severe/ESRD versus healthy matching subjects. Among six subjects enrolled in Part 1, percent ratios of least-squares mean and 90% confidence intervals (CIs) on dialysis and nondialysis days were 109.71 (CI: 97.23, 123.78) for maximum observed plasma concentration (Cmax); 108.39 (CI: 97.85, 120.07) for area under the concentration-time curve to the time of the last quantifiable plasma concentration (AUC0-t); and 109.98 (CI: 99.39, 121.70) for AUC extrapolated to infinity (AUC0-∞). These ranges were within 80%-125%, indicating no significant effect of dialysis on defibrotide exposure/clearance. In Part 2, defibrotide exposure parameters in six subjects with severe/ESRD after multiple doses (AUC0-t, 113 µg·h/mL; AUC over dosing interval, 113 µg·h/mL; Cmax, 53.8 µg/mL) were within 5%-8% of parameters after the first dose (AUC0-t, 117 µg·h/mL; AUC0-∞, 118 µg·h/mL; Cmax, 54.9 µg/mL), indicating no accumulation. Defibrotide peak and extent of exposures in those with severe/ESRD were ~35%-37% and 50%-60% higher, respectively, versus controls, following single and multiple doses. One adverse event (vomiting, possibly drug-related) was reported. These findings support defibrotide prescribing guidance stating no dose adjustment is necessary for hemodialysis or severe/ESRD.

  17. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chiappetta, R.F.

    An explosive`s velocity of detonation (VOD), can be used to indicate a number of important characteristics regarding the product`s performance under specific field and test conditions. A number of new characteristic and transient VOD curves have been identified in the field, which can be used to evaluate explosive performance, control ground vibration amplitudes and frequencies, select the correct amount and type of stemming for use at the collar and in stem decks, eliminate explosive desensitization, evaluate primer performance, design air deck based blasts, evaluate contaminated explosives and to overcome post blast noxious fumes. Tests were conducted over a six yearmore » period in single and multi-hole blasts using laboratory and full scale blast environments. Explosives tested ranged from pure Emulsion to Anfo and various grades of Emulsion/Anfo blends. Field test parameters were; borehole diameter (1 1/2--30 inches), hole depths (10--120 feet), primer size (0.5--6.4 pounds) and the blast environment varied from soft, jelly-like tar sands to some of the hardest iron ore formations. Most tests were instrumented with an array of blast monitoring instrumentation systems consisting of continuous velocity of detonation recorders, high-speed 16 mm cameras, laser-surveying instrumentation and seismographs which were placed in the near and far fields.« less

  18. Defibrotide, a polydisperse mixture of single-stranded phosphodiester oligonucleotides with lifesaving activity in severe hepatic veno-occlusive disease: clinical outcomes and potential mechanisms of action.

    PubMed

    Kornblum, Noah; Ayyanar, Kanyalakshmi; Benimetskaya, Luba; Richardson, Paul; Iacobelli, Massimo; Stein, C A

    2006-01-01

    Veno-occlusive disease of the liver (VOD) remains a troubling and potentially fatal complication of high-dose chemotherapy and hematopoietic stem cell transplantation conditioning regimens. No effective therapy has been available for these patients to date, and the best supportive care measures remain woefully inadequate. Defibrotide (DF) (Gentium, S.p.A., Como, Italy), a polydisperse mixture of all the single-stranded phosphodiester oligodeoxyribonucleotides that can be obtained from the controlled depolymerization of porcine intestinal mucosal genomic DNA, seems to offer a safe and effective treatment for some patients suffering from severe VOD, a condition for which no accepted standard therapy currently exists. Early clinical studies evaluating the efficacy of DF for the treatment of severe VOD in patients undergoing hematopoietic stem cell transplantation have been very encouraging. Approximately 45% of the patients treated in multiple initial phase II clinical trials achieved a complete response at day +100, demonstrating normalization of serum bilirubin and resolution of the clinical syndrome. However, although multi-institutional, these represented single arm studies. A large, FDA-approved, pivotal, prospective, multi-institutional, global phase III trial of DF vs. historical controls (best available therapy) commenced in the first quarter of 2006 and should provide further validation of DF's efficacy. The drug seems to have few significant side effects, and almost all test subjects who have received this treatment have tolerated it well. Although the mechanism of action remains unclear, the drug exerts minimal systemic anticoagulant effects yet appears to induce numerous antithrombotic and profibrinolytic effects both in vitro and in vivo. It may function as an adenosine receptor agonist and causes increased concentrations of endogenous prostaglandins, which modulate thrombomodulin, platelets, and fibrinolysis. It also appears to block lipopolysaccharide (LPS)-induced tissue factor (TF) expression. However, despite the fact the DF is composed of oligonucleotides, its mechanism of action, which at the present time is unclear, is not related to Watson-Crick base pair-dependent downregulation of gene expression but is rather likely a result of its polyanionic nature.

  19. Assessment of the Effect of Blast Hole Diameter on the Number of Oversize Boulders Using ANN Model

    NASA Astrophysics Data System (ADS)

    Dhekne, Prakash; Pradhan, Manoj; Jade, Ravi Krishnarao

    2016-04-01

    Now-a-days, blasts are planned using large diameter blast holes. The loading density (kg/m) and subsequently the energy available for the breakage of the rockmass increase with the diameter. The in-hole velocity of detonation (VoD) of non-ideal explosive also boosts up with the increase in diameter till the optimum diameter is reached. The increase in the energy content and in-hole VoD cause a sizable effect on the rock fragmentation. The effect can be assessed by counting the number of oversize boulders. This paper explains as to how the technique of artificial neural network modeling was used to predict the number of oversize boulders resulting from ANFO and SME blasts with blast holes of different diameters. The results from ANFO blasts indicated that there was no significant variation in the number of oversize boulders with the diameter whereas a perceptible variation was noticed in case of SME blasts with the change in the diameter. The change in the number of oversize boulders in ANFO blasts was negligible because mean energy factor remained almost same even when the diameter of the blast holes was altered. The decrease in the number of oversize boulders in SME blasts was on account of increase in mean energy factor when the blast hole diameter was increased. The increase in the in-hole VoD due to increase in the diameter of the hole was not found to have an effect on the generation of oversize boulders as this increase was not substantial both in SME and ANFO blasts.

  20. Pharmacokinetic profile of defibrotide in patients with renal impairment

    PubMed Central

    Tocchetti, Paola; Tudone, Elena; Marier, Jean-Francois; Marbury, Thomas C; Zomorodi, Katie; Eller, Mark

    2016-01-01

    Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is an unpredictable, potentially life-threatening complication of hematopoietic stem cell transplant conditioning. Severe VOD/SOS, generally associated with multiorgan dysfunction (pulmonary or renal dysfunction), may be associated with >80% mortality. Defibrotide, recently approved in the US, has demonstrated efficacy treating hepatic VOD/SOS with multiorgan dysfunction. Because renal impairment is prevalent in patients with VOD/SOS, this Phase I, open-label, two-part study in adults examined the effects of hemodialysis and severe or end-stage renal disease (ESRD) on defibrotide pharmacokinetics (PK). Part 1 compared defibrotide PK during single 6.25 mg/kg doses infused with and without dialysis. Part 2 assessed defibrotide plasma PK after multiple 6.25 mg/kg doses in nondialysis-dependent subjects with severe/ESRD versus healthy matching subjects. Among six subjects enrolled in Part 1, percent ratios of least-squares mean and 90% confidence intervals (CIs) on dialysis and nondialysis days were 109.71 (CI: 97.23, 123.78) for maximum observed plasma concentration (Cmax); 108.39 (CI: 97.85, 120.07) for area under the concentration–time curve to the time of the last quantifiable plasma concentration (AUC0–t); and 109.98 (CI: 99.39, 121.70) for AUC extrapolated to infinity (AUC0–∞). These ranges were within 80%–125%, indicating no significant effect of dialysis on defibrotide exposure/clearance. In Part 2, defibrotide exposure parameters in six subjects with severe/ESRD after multiple doses (AUC0–t, 113 µg·h/mL; AUC over dosing interval, 113 µg·h/mL; Cmax, 53.8 µg/mL) were within 5%–8% of parameters after the first dose (AUC0–t, 117 µg·h/mL; AUC0–∞, 118 µg·h/mL; Cmax, 54.9 µg/mL), indicating no accumulation. Defibrotide peak and extent of exposures in those with severe/ESRD were ~35%–37% and 50%–60% higher, respectively, versus controls, following single and multiple doses. One adverse event (vomiting, possibly drug-related) was reported. These findings support defibrotide prescribing guidance stating no dose adjustment is necessary for hemodialysis or severe/ESRD. PMID:27574402

  1. FDA Approval Summary: Mylotarg for Treatment of Patients with Relapsed or Refractory CD33-Positive Acute Myeloid Leukemia.

    PubMed

    Norsworthy, Kelly J; Ko, Chia-Wen; Lee, Jee Eun; Liu, Jiang; John, Christy S; Przepiorka, Donna; Farrell, Ann T; Pazdur, Richard

    2018-04-12

    On September 2, 2017, the U.S. Food and Drug Administration approved gemtuzumab ozogamicin (GO; Mylotarg; Pfizer, New York City, NY) for treatment of relapsed or refractory (R/R) CD33-positive acute myeloid leukemia (AML) in patients 2 years of age and older. GO is a CD33-directed antibody drug conjugate linked to the cytotoxic antibiotic calicheamicin. It originally received accelerated approval for treatment of older patients with relapsed CD33-positive AML in 2000, but it was withdrawn from the market in 2010 when the confirmatory trial failed to demonstrate clinical benefit among safety concerns, such as a higher rate of induction fatalities on the GO combination arm compared with chemotherapy alone. In addition, GO was associated with hepatic veno-occlusive disease (VOD), which has substantial morbidity and mortality. Pharmacokinetic analyses suggested a lower maximum concentration of GO would result in less VOD without affecting target saturation or efficacy. A meta-analysis across dose schedules of GO in patients with R/R AML showed that a lower-dose "fractionated" schedule of 3 mg/m 2 days 1, 4, and 7 was associated with less early mortality, hemorrhage, and VOD, without an apparent decrease in complete remission (CR) rate. MyloFrance 1 was a single-arm study evaluating response rates in patients with relapsed CD33-positive AML treated with the lower-dose fractionated GO regimen. The CR rate was 26% (95% confidence interval 16%-40%). Common adverse reactions were fever, infections, nausea, vomiting, constipation, bleeding, increased liver enzymes, and mucositis. There were no cases of VOD. These results supported the approval of GO as monotherapy for R/R CD33-positive AML using the lower-dose fractionated regimen. Gemtuzumab ozogamicin (GO) 3 mg/m 2 days 1, 4, and 7 is an active regimen for induction of remission when used to treat patients with relapsed or refractory CD33-positive acute myeloid leukemia without curative intent. The risks of hepatic veno-occlusive disease and early mortality with this regimen appear to be lower than reported previously for GO 9 mg/m 2 days 1 and 15. The data were not sufficient to enable conclusions about the safety of GO in children younger than 2 years of age. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  2. 75 FR 66433 - Mandatory Reporting of Greenhouse Gases

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... oxygen process furnace shops. Lime Production 327410 Calcium oxide, calcium hydroxide, dolomitic hydrates... Chemists AOD argon-oxygen decarburization API American Petroleum Institute ASTM American Society for... Mandates Reform Act of 1995 VOD vacuum oxygen decarburization Table of Contents I. Background A. How is...

  3. Variations in global land surface phenology: a comparison of satellite optical and passive microwave data

    NASA Astrophysics Data System (ADS)

    Tong, X.; Tian, F.; Brandt, M.; Zhang, W.; Liu, Y.; Fensholt, R.

    2017-12-01

    Changes in vegetation phenological events are among the most sensitive biological responses to climate change. In last decades, facilitating by satellite remote sensing techniques, land surface phenology (LSP) have been monitored at global scale using proxy approaches as tracking the temporal change of a satellite-derived vegetation index. However, the existing global assessments of changes in LSP are all established on the basis of leaf phenology using NDVI derived from optical sensors, being responsive to vegetation canopy cover and greenness. Instead, the vegetation optical depth (VOD) parameter from passive microwave sensors, which is sensitive to the aboveground vegetation water content by including as well the woody components in the observations, provides an alternative, independent and comprehensive means for global vegetation phenology monitoring. We used the unique long-term global VOD record available for the period 1992-2012 to monitoring the dynamics of LSP metrics (length of season, start of season and end of season) in comparison with the dynamics of LSP metrics derived from the latest GIMMS NDVI3G V1. We evaluated the differences in the linear trends of LSP metrics between two datasets. Currently, our results suggest that the level of seasonality variation of vegetation water content is less than the vegetation greenness. We found significant phenological changes in vegetation water content in African woodlands, where has been reported with little leaf phenological change regardless of the delays in rainfall onset. Therefore, VOD might allow us to detect temporal shifts in the timing difference of vegetation water storage vs. leaf emergence and to see if some ecophysiological thresholds seem to be reached, that could cause species turnover as climate change-driven alterations to the African monsoon proceed.

  4. THE NEXT GENERATION VIRGO CLUSTER SURVEY. XIX. TOMOGRAPHY OF MILKY WAY SUBSTRUCTURES IN THE NGVS FOOTPRINT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lokhorst, Deborah; Starkenburg, Else; Navarro, Julio F.

    2016-03-10

    The Next Generation Virgo Cluster Survey (NGVS) is a deep u*giz survey targeting the Virgo Cluster of galaxies at 16.5 Mpc. This survey provides high-quality photometry over an ∼100 deg{sup 2} region straddling the constellations of Virgo and Coma Berenices. This sightline through the Milky Way is noteworthy in that it intersects two of the most prominent substructures in the Galactic halo: the Virgo overdensity (VOD) and Sagittarius stellar stream (close to its bifurcation point). In this paper, we use deep u*gi imaging from the NGVS to perform tomography of the VOD and Sagittarius stream using main-sequence turnoff (MSTO) starsmore » as a halo tracer population. The VOD, whose centroid is known to lie at somewhat lower declinations (α ∼ 190°, δ ∼ −5°) than is covered by the NGVS, is nevertheless clearly detected in the NGVS footprint at distances between ∼8 and 25 kpc. By contrast, the Sagittarius stream is found to slice directly across the NGVS field at distances between 25 and 40 kpc, with a density maximum at ≃35 kpc. No evidence is found for new substructures beyond the Sagittarius stream, at least out to a distance of ∼90 kpc—the largest distance to which we can reliably trace the halo using MSTO stars. We find clear evidence for a distance gradient in the Sagittarius stream across the ∼30° of sky covered by the NGVS and its flanking fields. We compare our distance measurements along the stream with those predicted by leading stream models.« less

  5. Estimating ecosystem iso/anisohydry using microwave satellite data and its applications in ecohydrology

    NASA Astrophysics Data System (ADS)

    Li, Y.; Guan, K.; Gentine, P.; Konings, A. G.; Bhattacharya, A.; Meinzer, F. C.; Kimball, J. S.; Xu, X.; Anderegg, W.; McDowell, N. G.; Martínez-Vilalta, J.; Long, D. G.; Good, S. P.

    2017-12-01

    The concept of iso/anisohydry describes the degree to which plants regulate their water status, operating from isohydric with strict stomatal closure to anisohydric with greater stomatal conductance under drying conditions. Though some species-level measures of iso/anisohydry exist at limited locations, ecosystem scale information is still largely unavailable. In this study, we use diurnal observations from active (Ku-Band backscatter from QuikSCAT) and passive (X-band Vegetation Optical Depth [VOD] from AMSR-E) microwave satellite data to estimate global ecosystem iso/anisohydry. The two independent estimates from radar backscatter and VOD show good agreement at low and mid-latitudes but diverge at high latitudes. Grasslands, croplands, wetlands, and open shrublands are more anisohydric, whereas evergreen broadleaf and deciduous broadleaf forests are more isohydric. The direct validation with upscaled in-situ species iso/anisohydry estimates indicates that the VOD estimates have much better agreement than the backscatter in terms of their iso/anisohydry metrics. The indirect validation suggests that both estimates are consistent with prior knowledge that vegetation water status of anisohydric ecosystems more closely tracks environmental fluctuations of water availability and demand than their isohydric counterparts. The ecosystem level iso/anisohydry can be applied to reveal new insights into spatio-temporal ecosystem response to droughts. We conducted a case study to demonstrate the potential application of iso/anisohydry. We find that during the 2011 drought in US, over the drought affected region in the southern US, isohydric ecosystems experienced larger decline in productivity (NDVI and GPP) than anisohydric ones. However, during the 2012 drought in central US, both isohydric and anisohydric ecosystems exhibited similar decline in productivity.

  6. Development of multi-component explosive lenses for arbitrary phase velocity generation

    NASA Astrophysics Data System (ADS)

    Loiseau, Jason; Huneault, Justin; Petel, Oren; Goroshin, Sam; Frost, David; Higgins, Andrew; Zhang, Fan

    2013-06-01

    The combination of explosives with different detonation velocities and lens-like geometric shaping is a well-established technique for producing structured detonation waves. This technique can be extended to produce nearly arbitrary detonation phase velocities for the purposes of sequentially imploding pressurized tubes or driving Mach disks through high-density metalized explosives. The current study presents the experimental development of accelerating, multi-component lenses designed using simple geometric optics and idealized front curvature. The fast explosive component is either Composition C4 (VOD = 8 km/s) or Primasheet 1000 (VOD = 7 km/s), while the slow component varies from heavily amine-diluted nitromethane (amine mass fraction exceeding 20%) to packed metal and glass particle beds wetted with amine-sensitized nitromethane. The applicability of the geometric optic analog to such highly heterogeneous explosives is also investigated. The multi-layered lens technique is further developed as a means of generating a directed mass and momentum flux of metal particles via Mach-disk formation and jetting in circular and oval planar lenses.

  7. Analysis of an ABE Scheme with Verifiable Outsourced Decryption.

    PubMed

    Liao, Yongjian; He, Yichuan; Li, Fagen; Jiang, Shaoquan; Zhou, Shijie

    2018-01-10

    Attribute-based encryption (ABE) is a popular cryptographic technology to protect the security of users' data in cloud computing. In order to reduce its decryption cost, outsourcing the decryption of ciphertexts is an available method, which enables users to outsource a large number of decryption operations to the cloud service provider. To guarantee the correctness of transformed ciphertexts computed by the cloud server via the outsourced decryption, it is necessary to check the correctness of the outsourced decryption to ensure security for the data of users. Recently, Li et al. proposed a full verifiability of the outsourced decryption of ABE scheme (ABE-VOD) for the authorized users and unauthorized users, which can simultaneously check the correctness of the transformed ciphertext for both them. However, in this paper we show that their ABE-VOD scheme cannot obtain the results which they had shown, such as finding out all invalid ciphertexts, and checking the correctness of the transformed ciphertext for the authorized user via checking it for the unauthorized user. We first construct some invalid ciphertexts which can pass the validity checking in the decryption algorithm. That means their "verify-then-decrypt" skill is unavailable. Next, we show that the method to check the validity of the outsourced decryption for the authorized users via checking it for the unauthorized users is not always correct. That is to say, there exist some invalid ciphertexts which can pass the validity checking for the unauthorized user, but cannot pass the validity checking for the authorized user.

  8. Analysis of an ABE Scheme with Verifiable Outsourced Decryption

    PubMed Central

    He, Yichuan; Li, Fagen; Jiang, Shaoquan; Zhou, Shijie

    2018-01-01

    Attribute-based encryption (ABE) is a popular cryptographic technology to protect the security of users’ data in cloud computing. In order to reduce its decryption cost, outsourcing the decryption of ciphertexts is an available method, which enables users to outsource a large number of decryption operations to the cloud service provider. To guarantee the correctness of transformed ciphertexts computed by the cloud server via the outsourced decryption, it is necessary to check the correctness of the outsourced decryption to ensure security for the data of users. Recently, Li et al. proposed a full verifiability of the outsourced decryption of ABE scheme (ABE-VOD) for the authorized users and unauthorized users, which can simultaneously check the correctness of the transformed ciphertext for both them. However, in this paper we show that their ABE-VOD scheme cannot obtain the results which they had shown, such as finding out all invalid ciphertexts, and checking the correctness of the transformed ciphertext for the authorized user via checking it for the unauthorized user. We first construct some invalid ciphertexts which can pass the validity checking in the decryption algorithm. That means their “verify-then-decrypt” skill is unavailable. Next, we show that the method to check the validity of the outsourced decryption for the authorized users via checking it for the unauthorized users is not always correct. That is to say, there exist some invalid ciphertexts which can pass the validity checking for the unauthorized user, but cannot pass the validity checking for the authorized user. PMID:29320418

  9. Relative skills of soil moisture and vegetation optical depth retrievals for agricultural drought monitoring

    USDA-ARS?s Scientific Manuscript database

    Soil moisture condition is an important indicator for agricultural drought monitoring. Through the Land Parameter Retrieval Model (LPRM), vegetation optical depth (VOD) as well as surface soil moisture (SM) can be retrieved simultaneously from brightness temperature observations from the Advanced Mi...

  10. Assessing public benefits and costs of freight transportation projects : measuring shippers' value of delay on the freight system.

    DOT National Transportation Integrated Search

    2012-07-01

    Freight delay is detrimental to the national economy. In an effort to gauge the economic impact of freight delay due : to highway congestion, this project focuses on estimating shippers value of delay (VOD). We have accomplished : this through thr...

  11. The Vod Couple

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2009-01-01

    This article features two high school chemistry teachers, Aaron Sams and Jonathan Bergmann, who have overturned conventional classroom instruction by using video podcasts to form the root of a new learning model. Thumbing through an issue of "MacWorld" a few years ago, Aaron Sams was struck by an article about an application called ProfCast that…

  12. Inotuzumab ozogamicin in adults with relapsed or refractory CD22-positive acute lymphoblastic leukemia: a phase 1/2 study.

    PubMed

    DeAngelo, Daniel J; Stock, Wendy; Stein, Anthony S; Shustov, Andrei; Liedtke, Michaela; Schiffer, Charles A; Vandendries, Erik; Liau, Katherine; Ananthakrishnan, Revathi; Boni, Joseph; Laird, A Douglas; Fostvedt, Luke; Kantarjian, Hagop M; Advani, Anjali S

    2017-06-27

    This study evaluated the safety, antitumor activity, pharmacokinetics, and pharmacodynamics of inotuzumab ozogamicin (InO) for CD22-positive relapsed/refractory acute lymphoblastic leukemia. In phase 1, patients received InO 1.2 (n = 3), 1.6 (n = 12), or 1.8 (n = 9) mg/m 2 per cycle on days 1, 8, and 15 over a 28-day cycle (≤6 cycles). The recommended phase 2 dose (RP2D) was confirmed (expansion cohort; n = 13); safety and activity of InO were assessed in patients receiving the RP2D in phase 2 (n = 35) and in all treated patients (n = 72). The RP2D was 1.8 mg/m 2 per cycle (0.8 mg/m 2 on day 1; 0.5 mg/m 2 on days 8 and 15), with reduction to 1.6 mg/m 2 per cycle after complete remission (CR) or CR with incomplete marrow recovery (CRi). Treatment-related toxicities were primarily cytopenias. Four patients experienced treatment-related venoocclusive disease/sinusoidal obstruction syndrome (VOD/SOS; 1 fatal). Two VOD/SOS events occurred during treatment without intervening transplant; of 24 patients proceeding to poststudy transplant, 2 experienced VOD/SOS after transplant. Forty-nine (68%) patients had CR/CRi, with 41 (84%) achieving minimal residual disease (MRD) negativity. Median progression-free survival was 3.9 (95% confidence interval, 2.9-5.4) months; median overall survival was 7.4 (5.7-9.2) months for all treated patients, with median 23.7 (range, 6.8-29.8) months of follow-up for all treated patients alive at data cutoff. Achievement of MRD negativity was associated with higher InO exposure. InO was well tolerated and demonstrated high single-agent activity and MRD-negativity rates. This trial was registered at www.clinicaltrials.gov as #NCT01363297.

  13. Emulsion based cast booster - a priming system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gupta, R.N.; Mishra, A.K.

    2005-07-01

    This paper explores the potential of emulsion based cast booster to be used as primer to initiate bulk delivered emulsion explosives used in mines. An attempt has been made for comparative study between conventional cast booster and emulsion based cast booster in terms of the initiation process developed and their capability to develop and maintain the stable detonation process in the column explosives. The study has been conducted using a continuous velocity of detonation (VOD) measuring instrument. During this study three blasts have been monitored. In each blast two holes have been selected for study, the first hole being initiatedmore » with conventional cast booster while the other one with emulsion based cast booster. The findings of the study advocates that emulsion based cast booster is capable of efficient priming of bulk delivered column explosive with stable detonation process in the column. Further, the booster had advantages over the conventional PETN/TNT based cast booster. 5 refs., 2 figs., 1 tab., 1 photo.« less

  14. Update on the use of defibrotide.

    PubMed

    Guglielmelli, Tommasina; Bringhen, Sara; Palumbo, Antonio

    2012-03-01

    Defibrotide is a polydisperse oligonucleotide obtained from porcine intestinal mucosa and prepared by controlled depolymerization of DNA. It is a nucleic acid polymer, predominantly single-stranded, which has anti-ischemic and anti-thrombotic properties. The efficacy and safety of defibrotide in the treatment of veno-occlusive disease (VOD) occurring after high-dose chemotherapy and hematopoietic stem-cell transplantation is now well established in Phase II - III trials. A recent randomized, Phase III trial in pediatric patients has also demonstrated its role in the prevention of VOD. Preclinical studies reported the inhibitory effects of defibrotide on myeloma cells' growth through an antiangiogenic action and a regulation of the tumor-microenvironment interactions. A recent Phase II trial underlines the efficacy and safety of defibrotide-thalidomide-melphalan combination in the treatment of relapsed/refractory multiple myeloma. Defibrotide may be effective in the prophylaxis and the treatment of veno-occlusive disease. Recent experimental results suggest that defibrotide may belong to the new generation of anti-cancer drugs that can prevent tumor angiogenesis. In multiple myeloma, defibrotide may overcome the prothrombotic effect of thalidomide on endothelial cells. Further preclinical and clinical investigations are needed to assess the precise role of defibrotide in the treatment of patients with multiple myeloma.

  15. Framework for analysis of guaranteed QOS systems

    NASA Astrophysics Data System (ADS)

    Chaudhry, Shailender; Choudhary, Alok

    1997-01-01

    Multimedia data is isochronous in nature and entails managing and delivering high volumes of data. Multiprocessors with their large processing power, vast memory, and fast interconnects, are an ideal candidate for the implementation of multimedia applications. Initially, multiprocessors were designed to execute scientific programs and thus their architecture was optimized to provide low message latency and efficiently support regular communication patterns. Hence, they have a regular network topology and most use wormhole routing. The design offers the benefits of a simple router, small buffer size, and network latency that is almost independent of path length. Among the various multimedia applications, video on demand (VOD) server is well-suited for implementation using parallel multiprocessors. Logical models for VOD servers are presently mapped onto multiprocessors. Our paper provides a framework for calculating bounds on utilization of system resources with which QoS parameters for each isochronous stream can be guaranteed. Effects of the architecture of multiprocessors, and efficiency of various local models and mapping on particular architectures can be investigated within our framework. Our framework is based on rigorous proofs and provides tight bounds. The results obtained may be used as the basis for admission control tests. To illustrate the versatility of our framework, we provide bounds on utilization for various logical models applied to mesh connected architectures for a video on demand server. Our results show that worm hole routing can lead to packets waiting for transmission of other packets that apparently share no common resources. This situation is analogous to head-of-the-line blocking. We find that the provision of multiple VCs per link and multiple flit buffers improves utilization (even under guaranteed QoS parameters). This analogous to parallel iterative matching.

  16. Annual FAA Forecast Conference Proceedings (5th).

    DTIC Science & Technology

    1979-10-01

    UNCLASSFIEID N 11111 U-0 1 1112.0 IH ~ 118. MICROCOP RESOLUTION TEST NATI64Al. iUEUO Ao 1 c o 11th 4 4 v% ( 9 1 0 080 AVA n of raporatVod FoA Public 9egtn...bigger challenges that we face. There is no question public-because of the compounded effect of inflation that the acquisition rate of general aviation

  17. Same-session dorsal vein ligation and testing by intracavernous injection prior to penile prosthesis implantation (DVL-ICI-PPI).

    PubMed

    Shaeer, Osama; Shaeer, Kamal

    2014-09-01

    Complications of penile prosthesis implantation (PPI) are rare, nevertheless can be grave. In cases with veno-occlusive dysfunction (VOD), alternative surgical techniques such as dorsal vein ligation (DVL) are controversial. Some patients may opt for trial at DVL to avoid the possible complications of PPI. However, this may be associated with disappointment if DVL fails and another procedure is required. The aim if this study is to evaluate the results of a combined approach involving DVL, same-session testing by intracavernous injection (ICI) of prostaglandin E1 (PGE1), and immediate implantation of a penile prosthesis (PPI) in case of poor response to DVL. Long-term erectile function in cases with favorable intraoperative response to DVL. Twenty-six patients with refractory VOD were operated upon. Through a peno-pubic incision, DVL was performed, followed by ICI of 20 µg PGE1 in two divided doses, 10 µg each, 15 minutes apart. Group 1 exhibited full rigidity in response to the first dose. Group 2 exhibited full rigidity in response to the second dose. PPI was not performed for either. Group 3 exhibited suboptimal response to both doses, and PPI was performed through the same incision. Patients were followed up from 24 to 48 months using International Index of Erectile Function-5 scoring. For Group 1 (n = 8), six patients experienced normal erectile function following DVL throughout the whole follow-up period of 48 months (23.1% of all patients), and two patients relapsed. Group 2 (n = 6) (23.1%) reported normal erectile function for an average of 6 months, then relapsed. Group 3 (n = 12) had a penile prosthesis implanted in the same setting. Combined DVL-ICI-PPI can spare around 23.1% of young patients with VOD from PPI, at no additional risk. Full response to 10 µg PGE1 at intraoperative testing carries good prognosis to DVL on the long run. Investigation of a larger number of patients is necessary before reaching a final conclusion. © 2014 International Society for Sexual Medicine.

  18. European Union RACE program contributions to digital audiovisual communications and services

    NASA Astrophysics Data System (ADS)

    de Albuquerque, Augusto; van Noorden, Leon; Badique', Eric

    1995-02-01

    The European Union RACE (R&D in advanced communications technologies in Europe) and the future ACTS (advanced communications technologies and services) programs have been contributing and continue to contribute to world-wide developments in audio-visual services. The paper focuses on research progress in: (1) Image data compression. Several methods of image analysis leading to the use of encoders based on improved hybrid DCT-DPCM (MPEG or not), object oriented, hybrid region/waveform or knowledge-based coding methods are discussed. (2) Program production in the aspects of 3D imaging, data acquisition, virtual scene construction, pre-processing and sequence generation. (3) Interoperability and multimedia access systems. The diversity of material available and the introduction of interactive or near- interactive audio-visual services led to the development of prestandards for video-on-demand (VoD) and interworking of multimedia services storage systems and customer premises equipment.

  19. Fiber to the home: next generation network

    NASA Astrophysics Data System (ADS)

    Yang, Chengxin; Guo, Baoping

    2006-07-01

    Next generation networks capable of carrying converged telephone, television (TV), very high-speed internet, and very high-speed bi-directional data services (like video-on-demand (VOD), Game etc.) strategy for Fiber To The Home (FTTH) is presented. The potential market is analyzed. The barriers and some proper strategy are also discussed. Several technical problems like various powering methods, optical fiber cables, and different network architecture are discussed too.

  20. Analyzing Vehicle Operator Deviations

    DTIC Science & Technology

    2008-07-01

    Organization Report No. Scarborough A, Bailey L, Pounds J 9. Performing Organization Name and Address 10. Work Unit No. ( TRAIS ) FAA Civil...Investigation Reporting Form Instructions Use the accompanying flow charts (D4-D14) and Data Reporting Form (D15-D18) to document the results of the...happened, use the Entry Level Flow Chart (D3) to identify the relevant mental processes that were involved in the VOD. For each mental process identified

  1. Integrated multimedia information system on interactive CATV network

    NASA Astrophysics Data System (ADS)

    Lee, Meng-Huang; Chang, Shin-Hung

    1998-10-01

    In the current CATV system architectures, they provide one- way delivery of a common menu of entertainment to all the homes through the cable network. Through the technologies evolution, the interactive services (or two-way services) can be provided in the cable TV systems. They can supply customers with individualized programming and support real- time two-way communications. With a view to the service type changed from the one-way delivery systems to the two-way interactive systems, `on demand services' is a distinct feature of multimedia systems. In this paper, we present our work of building up an integrated multimedia system on interactive CATV network in Shih Chien University. Besides providing the traditional analog TV programming from the cable operator, we filter some channels to reserve them as our campus information channels. In addition to the analog broadcasting channel, the system also provides the interactive digital multimedia services, e.g. Video-On- Demand (VOD), Virtual Reality, BBS, World-Wide-Web, and Internet Radio Station. These two kinds of services are integrated in a CATV network by the separation of frequency allocation for the analog broadcasting service and the digital interactive services. Our ongoing work is to port our previous work of building up a VOD system conformed to DAVIC standard (for inter-operability concern) on Ethernet network into the current system.

  2. Satellite observed global variations in ecosystem-scale plant water storage

    NASA Astrophysics Data System (ADS)

    Tian, F.; Wigneron, J. P.; Brandt, M.; Fensholt, R.

    2017-12-01

    Plant water storage is a key component in ecohydrological processes and tightly coupled with global carbon and energy budgets. Field measurements of individual trees have revealed diurnal and seasonal variations in plant water storage across different tree species and sizes. However, global estimation of plant water storage is challenged by up-scaling from individual trees to an ecosystem scale. The L-band passive microwaves are sensitive to water stored in the stems, branches and leaves, with dependence on the vegetation structure. Thus, the L-band vegetation optical depth (L-VOD) parameter retrieved from satellite passive microwave observations can be used as a proxy for ecosystem-scale plant water storage. Here, we employ the recently developed SMOS (Soil Moisture and Ocean Salinity) L-VOD dataset to investigate spatial patterns in global plant water storage and its diurnal and seasonal variations. In addition, we compare the spatiotemporal patterns between plant water storage and canopy greenness (i.e., enhanced vegetation indices, EVI) to gain ecohydrological insights among different territorial biomes, including boreal forest and tropical woodland. Generally, seasonal dynamics of plant water storage is much smaller than canopy greenness, yet the temporal coupling of these two traits is totally different between boreal and tropical regions, which could be related to their strategies in plant water regulation.

  3. Cropland land surface phenology and seasonality in East Africa: Ethiopia, Tanzania, and South Sudan

    NASA Astrophysics Data System (ADS)

    Alemu, W. G.; Henebry, G. M.

    2015-12-01

    Most people in East Africa depend on rainfed agriculture. Rainfall in the region has been decreasing recently and is highly variable in space and time leading to high food insecurity. A comprehensive understanding of the regional cropland dynamics is therefore needed. Land surface phenology and land surface seasonality have important roles in monitoring cropland dynamics in a region with sparse coverage of in situ climatic and biophysical observations. However, commonly used optical satellite data are often degraded by cloud cover, aerosols, and dust and they are restricted to daytime observations. Here we used near-daily passive microwave (PM) data at 25 km spatial resolution from a series of microwave radiometers—AMSR-E, FengYun3B/MWRI, AMSR2—to study cropland dynamics for 2003-2013 in three important grain production areas of East Africa: Ethiopia, Tanzania, and South Sudan. PM data can be collected through clouds and at night. Based on Google Earth imagery, we identified several cropland areas corresponding to PM grid cells. Rainfall from TRMM and atmospheric water vapor (V) from PM data displayed temporal patterns that were unimodal in Ethiopia and South Sudan, but bimodal in Tanzania. We fitted convex quadratic models to link growing season increments of V and vegetation optical depth (VOD) to accumulated V (AV). The models yielded high coefficients of determination (r2 ≥0.8) and phenometrics calculated from the parameter coefficients. Peak rainfall lagged peak V, but preceded peak VOD. Growing degree-days (GDD), calculated from the PM air temperature data, displayed a weaker bimodal seasonality in which the lowest values occurred during the peak rainy season, due to the cooling effect of latent heat flux and coupled with higher reflection of insolation by the cloud deck. V as a function of GDD displays quasi-periodic behavior. Drier sites in the region displayed larger (smaller) intra-annual dynamic range of V (GDD) compared to the moister sites.

  4. Angiogenesis alteration by defibrotide: implications for its mechanism of action in severe hepatic veno-occlusive disease.

    PubMed

    Benimetskaya, Luba; Wu, Sijian; Voskresenskiy, Anatoliy M; Echart, Cinara; Zhou, Jin-Feng; Shin, Joongho; Iacobelli, Massimo; Richardson, Paul; Ayyanar, Kanyalakshmi; Stein, C A

    2008-11-15

    Defibrotide (DF) is a mixture of porcine-derived single-stranded phosphodiester oligonucleotides (9-80-mer; average, 50-mer) that has been successfully used to treat severe hepatic veno-occlusive disease (sVOD) with multiorgan failure (MOF) in patients who have received cytotoxic chemotherapy in preparation for bone marrow transplantation. However, its mechanism of action is unknown. Herein, we show that DF and phosphodiester oligonucleotides can bind to heparin-binding proteins (eg, basic fibroblast growth factor [bFGF] but not vascular endothelial growth factor [VEGF] 165) with low nanomolar affinity. This binding occurred in a length- and concentration-dependent manner. DF can mobilize proangiogenic factors such as bFGF from their depot or storage sites on bovine corneal endothelial matrix. However, these molecules do not interfere with high-affinity binding of bFGF to FGFR1 IIIc but can replace heparin as a required cofactor for binding and hence cellular mitogenesis. DF also protects bFGF against digestion by trypsin and chymotrypsin and from air oxidation. In addition, DF binds to collagen I with low nanomolar affinity and can promote human microvascular endothelial cell-1 (HMEC-1) cell mitogenesis and tubular morphogenesis in three-dimensional collagen I gels. Thus, our data suggest that DF may provide a stimulus to the sinusoidal endothelium of a liver that has suffered a severe angiotoxic event, thus helping to ameliorate the clinical sVOD/MOF syndrome.

  5. Herbal medicines and veno-occlusive disease in India.

    PubMed Central

    Datta, D. V.; Khuroo, M. S.; Mattocks, A. R.; Aikat, B. K.; Chhuttani, P. N.

    1978-01-01

    Six cases are described of veno-occlusive disease (VOD) after medicinal herb ingestion. The herb Heliotropium eichwaldii, taken by three patients, was found to contain the toxic pyrrolizidine alkaloid, heliotrine. Two patients presented with fulminant hepatic failure while the other four patients had a clinical picture suggestive of decompensated cirrhosis. The medical use of this herb may possibly be responsible for a significant proportion of acute and chronic liver disease in India, making it of public health importance. Images Fig. 1 Fig. 2 Fig. 3 PMID:733681

  6. Climatic drivers of vegetation based on wavelet analysis

    NASA Astrophysics Data System (ADS)

    Claessen, Jeroen; Martens, Brecht; Verhoest, Niko E. C.; Molini, Annalisa; Miralles, Diego

    2017-04-01

    Vegetation dynamics are driven by climate, and at the same time they play a key role in forcing the different bio-geochemical cycles. As climate change leads to an increase in frequency and intensity of hydro-meteorological extremes, vegetation is expected to respond to these changes, and subsequently feed back on their occurrence. This response can be analysed using time series of different vegetation diagnostics observed from space, in the optical (e.g. Normalised Difference Vegetation Index (NDVI), Solar Induced Fluorescence (SIF)) and microwave (Vegetation Optical Depth (VOD)) domains. In this contribution, we compare the climatic drivers of different vegetation diagnostics, based on a monthly global data-cube of 24 years at a 0.25° resolution. To do so, we calculate the wavelet coherence between each vegetation-related observation and observations of air temperature, precipitation and incoming radiation. The use of wavelet coherence allows unveiling the scale-by-scale response and sensitivity of the diverse vegetation indices to their climatic drivers. Our preliminary results show that the wavelet-based statistics prove to be a suitable tool for extracting information from different vegetation indices. Going beyond traditional methods based on linear correlations, the application of wavelet coherence provides information about: (a) the specific periods at which the correspondence between climate and vegetation dynamics is larger, (b) the frequencies at which this correspondence occurs (e.g. monthly or seasonal scales), and (c) the time lag in the response of vegetation to their climate drivers, and vice versa. As expected, areas of high rainfall volumes are characterised by a strong control of radiation and temperature over vegetation. Furthermore, precipitation is the most important driver of vegetation variability over short terms in most regions of the world - which can be explained by the rapid response of leaf development towards available water content - while at seasonal scales the vegetative response is dominated by solar radiation in most regions. At the higher latitudes, the trends in all vegetation diagnostics agree with the hypothesis of a greening pattern explained by the increase in temperature. At the same time, substantial differences can be observed between the responses of the different vegetation indices as well. As an example, the VOD - thought to be a close proxy for vegetation water content - shows a larger sensitivity to precipitation than traditional optical indices like the NDVI. Our findings help to further understand the physical attributes of vegetation that each remotely-sensed vegetation index is responding to in order to optimize their use in global bio-geoscience research.

  7. Early stellate cell activation and veno-occlusive-disease (VOD)-like hepatotoxicity in dogs treated with AR-H047108, an imidazopyridine proton pump inhibitor.

    PubMed

    Berg, Anna-Lena; Böttcher, Gerhard; Andersson, Kjell; Carlsson, Enar; Lindström, Anna-Karin; Huby, Russell; Håkansson, Helen; Skånberg-Wilhelmsson, Inger; Hellmold, Heike

    2008-07-01

    Dogs treated with AR-H047108, an imidazopyridine potassium competitive acid blocker (P-CAB), developed clinical signs of hepatic dysfunction as well as morphologically manifest hepatotoxicity in repeat-dose toxicity studies. An investigative one-month study was performed, with interim euthanasia after one and two weeks. A detailed histopathological and immunohistochemical characterization of the liver lesions was conducted, including markers for fibrosis, Kupffer cell activation, apoptosis, and endothelial injury. In addition, hepatic retinoid and procollagen 1alpha2 mRNA levels in livers of dogs treated with AR-H047108 were analyzed. The results showed an early inflammatory process in central veins and centrilobular areas, present after one week of treatment. This inflammatory reaction was paralleled by activation of stellate/Ito cells to myofibroblasts and was associated with sinusoidal and centrivenular fibrosis. The early activation of stellate cells coincided with a significant decrease in retinyl ester levels, and a significant increase in procollagen 1alpha2 mRNA levels, in the liver. At later time points (three and six months), there was marked sinusoidal fibrosis in centrilobular areas, as well as occlusion of central veins resulting from a combination of fibrosis and increased thickness of smooth muscle bundles in the vessel wall. The pattern of lesions suggests a veno-occlusive-disease (VOD)-like scenario, possibly linked to the imidazopyridine chemical structure of the compound facilitated by specific morphological features of the dog liver.

  8. Circulatory kinetics of intravenously injected {sup 238}Pu(IV) citrate and {sup 14}C-CaNa{sub 3}-DTPA in mice: Comparison with rat, dog, and Reference Man

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Durbin, P.W.; Kullgren, B.; Schmidt, C.T.

    1997-02-01

    New ligands for in vivo chelation of Pu(IV) are being synthesized and evaluated in mice for efficacy and toxicity. Biokinetic studies of the new ligands, CaNa{sub 3}-DTPA, and Pu(IV) are major components of those investigations. Young adult female mice were injected intravenously (iv) with {sup 3}H-inulin, {sup 14}C-CaNa{sub 3}-DTPA, or {sup 238}Pu(IV) citrate to provide base- line data for plasma clearance, tissue uptake, and excretion rates and to determine the dilution volume (VOD) and renal clearance rate (RC) of filterable substances. Published plasma clearance data in Reference Man, dog, and rat were collected. Based on combined data for {sup 3}H-inulinmore » and {sup 14}C-CaNa{sub 3}-DTPA, VOD = 17% of body weight and RC = 18 mL kg{sup -1} min{sup -1} for mice. Retention of {sup 14}C-CaNa{sub 3}-DTPA in the four species is proportional to body weight and inversely proportional to RC: Integrals of the retention of {sup 14}C-CaNa{sub 3}-DTPA from R(t) = 1.0 to R(t) = 0.05 are 108, 43, 28, and 10 DF min, respectively, for Reference Man, dog, rat, and mouse. Clearances of iv-injected Pu(IV) citrate from plasma are in the same order: The plasma curve integrals from injection to 1440 min are 840, 640, 280, and 67 DF min, respectively, for Reference Man, dog, rat, and mouse. In mice, a large fraction of newly injected Pu(IV) is rapidly transferred to the interstitial water of bulk soft tissue (excluding liver and kidneys), from which it is cleared at the same rate as from the plasma. Rapid plasma clearance, escape into interstitial water (22%ID at 20 min), significant early urinary excretion (8%ID in 12 h), and prompt deposition in liver and skeleton (complete in 12 h) are evidence of inefficient binding to plasma protein of newly injected Pu(IV) in mice. Slow plasma clearance, little early urinary excretion, and delayed deposition in liver and skeleton reflect more efficient binding of newly injected Pu(IV) in Reference Man and dog. 39 refs., 6 figs., 3 tabs.« less

  9. Bandwidth reduction for video-on-demand broadcasting using secondary content insertion

    NASA Astrophysics Data System (ADS)

    Golynski, Alexander; Lopez-Ortiz, Alejandro; Poirier, Guillaume; Quimper, Claude-Guy

    2005-01-01

    An optimal broadcasting scheme under the presence of secondary content (i.e. advertisements) is proposed. The proposed scheme works both for movies encoded in a Constant Bit Rate (CBR) or a Variable Bit Rate (VBR) format. It is shown experimentally that secondary content in movies can make Video-on-Demand (VoD) broadcasting systems more efficient. An efficient algorithm is given to compute the optimal broadcasting schedule with secondary content, which in particular significantly improves over the best previously known algorithm for computing the optimal broadcasting schedule without secondary content.

  10. Oral 6-mercaptopurine versus oral 6-thioguanine and veno-occlusive disease in children with standard-risk acute lymphoblastic leukemia: report of the Children's Oncology Group CCG-1952 clinical trial

    PubMed Central

    Matloub, Yousif; Broxson, Emmett; La, Mei; Yanofsky, Rochelle; Sather, Harland; Hutchinson, Ray; Heerema, Nyla A.; Sorrell, April D.; Masterson, Margaret; Bleyer, Archie; Gaynon, Paul S.

    2010-01-01

    The Children's Cancer Group 1952 (CCG-1952) clinical trial studied the substitution of oral 6-thioguanine (TG) for 6-mercaptopurine (MP) and triple intrathecal therapy (ITT) for intrathecal methotrexate (IT-MTX) in the treatment of standard-risk acute lymphoblastic leukemia. After remission induction, 2027 patients were randomized to receive MP (n = 1010) or TG (n = 1017) and IT-MTX (n = 1018) or ITT (n = 1009). The results of the thiopurine comparison are as follows. The estimated 7-year event-free survival (EFS) for subjects randomized to TG was 84.1% (± 1.8%) and to MP was 79.0% (± 2.1%; P = .004 log rank), although overall survival was 91.9% (± 1.4%) and 91.2% (± 1.5%), respectively (P = .6 log rank). The TG starting dose was reduced from 60 to 50 mg/m2 per day after recognition of hepatic veno-occlusive disease (VOD). A total of 257 patients on TG (25%) developed VOD or disproportionate thrombocytopenia and switched to MP. Once portal hypertension occurred, all subjects on TG were changed to MP. The benefit of randomization to TG over MP, as measured by EFS, was evident primarily in boys who began TG at 60 mg/m2 (relative hazard rate [RHR] 0.65, P = .002). The toxicities of TG preclude its protracted use as given in this study. This study is registered at http://clinicaltrials.gov as NCT00002744. PMID:20124218

  11. [Myometrial invasion as a prognostic factor in endometrial adenocarcinoma].

    PubMed

    Mihalcea, D; Aursulesei, D

    2009-01-01

    Myometrial invasion is one of the most important prognostic factors in endometrial cancer. We have studied a cohort of 62 patients with endometrial cancer who underwent surgery in 4-th Gynecology Clinic of "Cuza Vodă" Hospital, Iaşi between 1997-2008. Myometrial invasion was determined intraoperatory by gross visual inspection and frozen section exam and by histopathological exam after surgery. We have investigated the relationship between myometrial invasion and other prognostic factors: histological type, grading and lymph node metastasis. In 36 cases the invasion was absent or minimal, and only in a cases the myometrum was completely invaded.

  12. Logistical Support of AirLand Operations: Myth or Magic?

    DTIC Science & Technology

    1992-05-04

    I4 May 1992 Master’s Thesis, 4 Aug 91-5 Jun 92 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS .Support of AirLand Operations: Myth or Magic 6. AUTHOR(S) HA•J...SUPPORT OF AIRLAND OPERATIONS: MYTH OR MAGIC A thesis nresented to the Faculty of the U.S. Army Command and General Staff College in oartial fulfillment of...inerati,,,: Myth or Magic . Aprroved by: .Theq is Comni tt-t- fTh~airrnan; J ),I i .5 .a rria A.n . T.T! 3:•, J!. Pnwe r. M’. P. A . " ,ý) VoD" Member

  13. Analysis and application of intelligence network based on FTTH

    NASA Astrophysics Data System (ADS)

    Feng, Xiancheng; Yun, Xiang

    2008-12-01

    With the continued rapid growth of Internet, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. The bandwidth requirement increase continuously. Network technique, optical device technical development is swift and violent. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network. Firstly, it introduces the main service which FTTH supports, main analysis key technology such as FTTH system composition way, topological structure, multiplexing, optical cable and device. It focus two kinds of realization methods - PON, P2P technology. Then it proposed that the solution of FTTH can support comprehensive access (service such as broadband data, voice, video and narrowband private line). Finally, it shows the engineering application for FTTH in the district and building. It brings enormous economic benefits and social benefit.

  14. A new IPQAM modulator with high integrated degree for digital TV

    NASA Astrophysics Data System (ADS)

    He, Yejun; Liu, Deming; Zhu, Guangxi; Jiang, Tao; Sun, Gongxian

    2008-12-01

    As video on demand (VOD) services are deployed, cable operators will experience a fundamental shift in their business, moving from broadcast to unicast content delivery. Another significant change is the introduction of Gigabit Ethernet into their network, which is providing an unprecedented opportunity to turn the cable operator's infrastructure into a sustainable competitive advantage. However, Gigabit Ethernet is more than just transport; it's the foundation of the Next-Generation Digital Video Network. IPQAM modulator, which is a main equipment, aren't made in China so far. It is the first time that we did design IPQAM modulator and will apply it to interactive TV based on DWDM (dense wavelength-division multiplexing). This paper introduces the principle of IPQAM modulator and transmission approach. The differences between IPQAM and conventional QAM are analysed. Some key techniques such as scrambling, statistical multiplexing, Data over Cable Service Interface Specification (DOCSIS) 3.0, software defined radio as well as DVB simulcrypt are also studied.

  15. Design definition study of a lift/cruise fan technology V/STOL aircraft. Volume 1: Navy operational aircraft

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Aircraft were designed and sized to meet Navy mission requirements. Five missions were established for evaluation: anti-submarine warfare (ASW), surface attack (SA), combat search and rescue (CSAR), surveillance (SURV), and vertical on-board delivery (VOD). All missions were performed with a short takeoff and a vertical landing. The aircraft were defined using existing J97-GE gas generators or reasonable growth derivatives in conjunction with turbotip fans reflecting LF460 type technology. The multipurpose aircraft configuration established for U.S. Navy missions utilizes the turbotip driven lift/cruise fan concept for V/STOL aircraft.

  16. Soil moisture extremes drive tree canopy death in 2011 Texas drought: multispectral (Landsat, NAIP) and L-band passive microwave remote sensing (SMOS-IC)

    NASA Astrophysics Data System (ADS)

    Swenson, J. J.; Schwantes, A. M.; Johnson, D. M.; Domec, J. C.; Wigneron, J. P.

    2017-12-01

    Climate change is bringing more frequent and intense droughts that are causing broad scale tree mortality events. Detecting regional drought stress is now more frequently monitored with passive microwave satellite sensing of soil moisture (SM) and vegetation water status (through the vegetation optical depth (VOD) index), that can be validated with in-situ measurements of soil moisture or corroborated with satellite multispectral indices of greenness. The detection of canopy death however marks the passing of a definitive physiological threshold. We compare soil moisture from the L-band SMOS-IC passive microwave product (2010-20176) to an accurate and detailed (30-m spatial resolution) map of canopy loss across the US state of Texas during the record breaking 2011 drought. The SMOS-IC product (25 km) is a new and simpler product of soil moisture and VOD that has been shown to be more accurate than past SMOS products and it is independent of ancillary data. Canopy loss was mapped from Landsat imagery trained with 186, 41 km2 subplots of classified National Agriculture Inventory Program color infrared aerial imagery recorded before and after the drought. Bringing these two datasets of disparate spatial resolution together and averaging them across the state, we find that areas with at least 25% tree cover that experienced the most canopy loss (highest quartile) had lower soil moisture compared to areas with less canopy loss in 2011. These areas with the most loss, experienced up to 9 weeks of the growing season at < 0.05 SM (m3/m3), while the rest of Texas forests, experienced just 1 week at that SM. The following years, 2012 - 2016, dropped below 0.05 SM very rarely (two weeks each in 2012 and 2015, and never for 2013, 2014, 2016). Forests during the drought of 2011 experienced the absolute lowest SM (0.031) and had the earliest onset of low SM across the 6 years analyzed. Analyzing areas of drought induced canopy loss with SM preceding and during drought across a large area provides the opportunity to better understand plant behavior under stress as well as the effects of topography, soil, and climate. Having more information on plant hydraulic limits would lend itself to modeling and prediction of die offs based on satellite tracked SM.

  17. Digital cinema system using JPEG2000 movie of 8-million pixel resolution

    NASA Astrophysics Data System (ADS)

    Fujii, Tatsuya; Nomura, Mitsuru; Shirai, Daisuke; Yamaguchi, Takahiro; Fujii, Tetsuro; Ono, Sadayasu

    2003-05-01

    We have developed a prototype digital cinema system that can store, transmit and display extra high quality movies of 8-million pixel resolution, using JPEG2000 coding algorithm. The image quality is 4 times better than HDTV in resolution, and enables us to replace conventional films with digital cinema archives. Using wide-area optical gigabit IP networks, cinema contents are distributed and played back as a video-on-demand (VoD) system. The system consists of three main devices, a video server, a real-time JPEG2000 decoder, and a large-venue LCD projector. All digital movie data are compressed by JPEG2000 and stored in advance. The coded streams of 300~500 Mbps can be continuously transmitted from the PC server using TCP/IP. The decoder can perform the real-time decompression at 24/48 frames per second, using 120 parallel JPEG2000 processing elements. The received streams are expanded into 4.5Gbps raw video signals. The prototype LCD projector uses 3 pieces of 3840×2048 pixel reflective LCD panels (D-ILA) to show RGB 30-bit color movies fed by the decoder. The brightness exceeds 3000 ANSI lumens for a 300-inch screen. The refresh rate is chosen to 96Hz to thoroughly eliminate flickers, while preserving compatibility to cinema movies of 24 frames per second.

  18. Ferritin as an early marker of graft rejection after allogeneic hematopoietic stem cell transplantation in pediatric patients.

    PubMed

    Döring, Michaela; Cabanillas Stanchi, Karin Melanie; Feucht, Judith; Queudeville, Manon; Teltschik, Heiko-Manuel; Lang, Peter; Feuchtinger, Tobias; Handgretinger, Rupert; Müller, Ingo

    2016-01-01

    Diagnosis of adverse events following hematopoietic stem cell transplantation (HSCT) is mainly assigned to clinical symptoms or biopsies and thus rather unspecific and/or invasive. Studies indicate a distinct role of serum ferritin in HSCT and its correlation with adverse events such as graft-versus-host disease (GvHD), veno-occlusive disease (VOD), or infections. However, published data on the relevance of ferritin as a prognostic marker for post-transplant adverse events is rare, especially in pediatric patients. The present study analyzes ferritin plasma concentrations of 138 pediatric patients after HSCT between 2007 and 2010 including the control group (n = 21). Given the initial results regarding ferritin as a significant predictor for acute graft rejection after allogeneic HSCT in 9 of the 138 pediatric patients, serum ferritin of all pediatric patients (n = 27) who experienced graft rejection between 2007 and 2014 was analyzed. In addition, laboratory parameters including C-reactive protein (CRP), lactate dehydrogenase (LDH), fibrinogen, and D-dimer as possible differentiation markers for graft rejection were determined. In 24 (88.9 %) of the 27 pediatric patients with graft rejection, a significant increase of ferritin levels was observed 1 to 7 days prior to (P < 0.0001) and at the time of graft rejection (P < 0.0001). Moreover, there was an increase of D-dimer, CRP, LDH, and fibrinogen 1-7 days before graft rejection. Ferritin increased significantly at time of VOD (P = 0.0067), at time of intestinal (P < 0.0001) and skin GvHD (P < 0.0001), and at time of sepsis (P = 0.0005) and bacteremia (P = 0.0029). Ferritin might serve as a readily available identification marker for differentiation and identification of adverse events after HSCT in combination with other laboratory markers.

  19. A pilot study and novel angiographic classification for superior sagittal sinus stenting in patients with non-thrombotic intracranial venous occlusive disease.

    PubMed

    Raper, Daniel M S; Buell, Thomas J; Ding, Dale; Pomeraniec, I Jonathan; Crowley, R Webster; Liu, Kenneth C

    2018-01-01

    Safety and efficacy of superior sagittal sinus (SSS) stenting for non-thrombotic intracranial venous occlusive disease (VOD) is unknown. The aim of this retrospective cohort study is to evaluate outcomes after SSS stenting. We evaluated an institutional database to identify patients who underwent SSS stenting. Radiographic and clinical outcomes were analyzed and a novel angiographic classification of the SSS was proposed. We identified 19 patients; 42% developed SSS stenosis after transverse sinus stenting. Pre-stent maximum mean venous pressure (MVP) in the SSS of 16.2 mm Hg decreased to 13.1 mm Hg after stenting (p=0.037). Preoperative trans-stenosis pressure gradient of 4.2 mm Hg decreased to 1.5 mm Hg after stenting (p<0.001). No intraprocedural complication or junctional SSS stenosis distal to the stent construct was noted. Improvement in headache, tinnitus, and visual obscurations was reported by 66.7%, 63.6%, and 50% of affected patients, respectively, at mean follow-up of 5.2 months. We divided the SSS into four anatomically equal segments, numbered S1-S4, from the torcula to frontal pole. SSS stenosis typically occurs in the S1 segment, and the anterior extent of SSS stents was deployed at the S1-S2 junction in all but one case. SSS stenting is reasonably safe, may improve clinical symptoms, and significantly reduces maximum MVP and trans-stenosis pressure gradients in patients with VOD with SSS stenosis. The S1 segment is most commonly stenotic, and minimum pressure gradients for symptomatic SSS stenosis may be lower than for transverse or sigmoid stenosis. Additional studies and follow-up are necessary to better elucidate appropriate clinical indications and long-term efficacy of SSS stenting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. The global SMOS Level 3 daily soil moisture and brightness temperature maps

    NASA Astrophysics Data System (ADS)

    Bitar, Ahmad Al; Mialon, Arnaud; Kerr, Yann H.; Cabot, François; Richaume, Philippe; Jacquette, Elsa; Quesney, Arnaud; Mahmoodi, Ali; Tarot, Stéphane; Parrens, Marie; Al-Yaari, Amen; Pellarin, Thierry; Rodriguez-Fernandez, Nemesio; Wigneron, Jean-Pierre

    2017-06-01

    The objective of this paper is to present the multi-orbit (MO) surface soil moisture (SM) and angle-binned brightness temperature (TB) products for the SMOS (Soil Moisture and Ocean Salinity) mission based on a new multi-orbit algorithm. The Level 3 algorithm at CATDS (Centre Aval de Traitement des Données SMOS) makes use of MO retrieval to enhance the robustness and quality of SM retrievals. The motivation of the approach is to make use of the longer temporal autocorrelation length of the vegetation optical depth (VOD) compared to the corresponding SM autocorrelation in order to enhance the retrievals when an acquisition occurs at the border of the swath. The retrieval algorithm is implemented in a unique operational processor delivering multiple parameters (e.g. SM and VOD) using multi-angular dual-polarisation TB from MO. A subsidiary angle-binned TB product is provided. In this study the Level 3 TB V310 product is showcased and compared to SMAP (Soil Moisture Active Passive) TB. The Level 3 SM V300 product is compared to the single-orbit (SO) retrievals from the Level 2 SM processor from ESA with aligned configuration. The advantages and drawbacks of the Level 3 SM product (L3SM) are discussed. The comparison is done on a global scale between the two datasets and on the local scale with respect to in situ data from AMMA-CATCH and USDA ARS Watershed networks. The results obtained from the global analysis show that the MO implementation enhances the number of retrievals: up to 9 % over certain areas. The comparison with the in situ data shows that the increase in the number of retrievals does not come with a decrease in quality, but rather at the expense of an increased time lag in product availability from 6 h to 3.5 days, which can be a limiting factor for applications like flood forecast but reasonable for drought monitoring and climate change studies. The SMOS L3 soil moisture and L3 brightness temperature products are delivered using an open licence and free of charge using a web application (https://www.catds.fr/sipad/). The RE04 products, versions 300 and 310, used in this paper are also available at ftp://ext-catds-cpdc:catds2010@ftp.ifremer.fr/Land_products/GRIDDED/L3SM/RE04/.

  1. Norfolk Lake Highway Bridges, Baxter County, Arkansas, White River and Tributaries, North Fork River, Arkansas Foundation Report.

    DTIC Science & Technology

    1983-06-01

    50 19 F20 mi mune d o f Cry-o Hadboto swi ve I I OL~~ Hzr Har Str 5 -45 H0 Back on !4rpn -USANDY DOLQ-1rrE - Vod ’og - 2 R r Ard - ard ---5 2 r...t OFOPALC70 * C",.. 0E- ** 36.78 1466.581 R~ktt I lrAtI- SAND Str 33 19 Is.. /2 mn CEIMnq GROUT - - 1 1M *-..dd Rou. 156:22 Stem Ke 465.4 /-yecg...FCAO O . . - L o ’ str Woeror e E.-IS 533.4’ I0 Rate cont L C , Dolomite - Grey - Hard 21 nd 17rpm 57. - Silic Kelly & DH Ass: 532.9’ 50 10.2 -S, -a’i

  2. A global satellite environmental data record derived from AMSR-E and AMSR2 microwave Earth observations

    NASA Astrophysics Data System (ADS)

    Du, Jinyang; Kimball, John S.; Jones, Lucas A.; Kim, Youngwook; Glassy, Joseph; Watts, Jennifer D.

    2017-11-01

    Spaceborne microwave remote sensing is widely used to monitor global environmental changes for understanding hydrological, ecological, and climate processes. A new global land parameter data record (LPDR) was generated using similar calibrated, multifrequency brightness temperature (Tb) retrievals from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and the Advanced Microwave Scanning Radiometer 2 (AMSR2). The resulting LPDR provides a long-term (June 2002-December 2015) global record of key environmental observations at a 25 km grid cell resolution, including surface fractional open water (FW) cover, atmosphere precipitable water vapor (PWV), daily maximum and minimum surface air temperatures (Tmx and Tmn), vegetation optical depth (VOD), and surface volumetric soil moisture (VSM). Global mapping of the land parameter climatology means and seasonal variability over the full-year records from AMSR-E (2003-2010) and AMSR2 (2013-2015) observation periods is consistent with characteristic global climate and vegetation patterns. Quantitative comparisons with independent observations indicated favorable LPDR performance for FW (R ≥ 0.75; RMSE ≤ 0.06), PWV (R ≥ 0.91; RMSE ≤ 4.94 mm), Tmx and Tmn (R ≥ 0.90; RMSE ≤ 3.48 °C), and VSM (0.63 ≤ R ≤ 0.84; bias-corrected RMSE ≤ 0.06 cm3 cm-3). The LPDR-derived global VOD record is also proportional to satellite-observed NDVI (GIMMS3g) seasonality (R ≥ 0.88) due to the synergy between canopy biomass structure and photosynthetic greenness. Statistical analysis shows overall LPDR consistency but with small biases between AMSR-E and AMSR2 retrievals that should be considered when evaluating long-term environmental trends. The resulting LPDR and potential updates from continuing AMSR2 operations provide for effective global monitoring of environmental parameters related to vegetation activity, terrestrial water storage, and mobility and are suitable for climate and ecosystem studies. The LPDR dataset is publicly available at http://files.ntsg.umt.edu/data/LPDR_v2/.<

  3. Sinusoidal obstruction syndrome.

    PubMed

    Valla, Dominique-Charles; Cazals-Hatem, Dominique

    2016-09-01

    Sinusoidal obstruction syndrome (SOS) is characterized by damage to small hepatic vessels affecting particularly sinusoidal endothelium. Damaged sinusoids can be associated with a partial or complete occlusion of small hepatic veins, hence the previous denomination of hepatic veno-occlusive disease (VOD). Exposure to certain exogenous toxins appears to be specific to this condition and is frequently included in its definition. Typical histopathological features of SOS in a liver biopsy specimen are presented in the text. The purpose of this article is to provide an overview on the different entities corresponding to this general definition. Such entities include: (i) liver disease related to pyrrolizidine alcaloids; (ii) liver injury related to conditioning for hematopoietic stem cell transplantation; (iii) vascular liver disease occurring in patients treated with chemotherapy for liver metastasis of colorectal cancer; and (iv) other liver diseases related to toxic agents. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. [Thrombotic Microangiopathies].

    PubMed

    Schubert, Jörg; Dechant, Michael

    2018-06-01

    Thrombotic microangiopathies are almost devastating diseases leading to death at high frequency if untreated. They consist of at least five distinct entities, TTP, HUS, aHUS, TMA due to drug interference, systemic disease or post therapy TMA. Around 10 years ago there was only one established therapeutic approach as plasmapheresis. Meanwhile, there are new drugs been licensed or within licensing process. Patients with atypical HUS can be treated successfully by the Complement inhibitor Eculizumab. In addition, there is a new inhibitor of von-Willebrand-Polymerisation available. Caplacizumab provides a significantly better remission and decrease in TMA-related death. For therapy associated TMA as VOD/SOS Defibrotide could be established within a phase III study to significantly improve outcomes. In order to select these new medical approaches individual diagnostic parameters need to be established in order to rapidly distinguish between the TMA entities and start targeted therapy. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Investigation of Mineral Alteration in Andesite and Dacite from Three Different Volcano Hydrothermal Systems on Dominica, Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Smith, C. I. V.; Frey, H. M.; Joseph, E. P.; Manon, M. R. F.

    2017-12-01

    The thermal discharges of Dominica are classified as steam-heated acidic-sulphate waters, produced by the mixing of shallow ground waters heated by sulphur bearing gases coming from magmatic sources. This study investigates the mineral alteration associated with three hydrothermal areas in Dominica that exhibit different temperature, pH, water composition and surface water abundance. Hydrothermal features (fumaroles, pools, springs) from Sulphur Springs ranged in temperature from 41 - 97 °C and pH from 1-3 in a predominantly gaseous environment, whereas the Valley of Desolation (69-98 °C and pH 1- 4) and the Cold Soufriere (18-32 °C and pH 1-4) have significant inputs of surface water. At each location, the host andesite-dacite rock was enveloped by a thin rind (up 2 cm) of precipitates, but the degree of alteration and rind thickness/composition varied with location. Cobbles from Sulphur Springs (SS) are grayish white in color with a thin outer rind (3-13 mm), and seemingly unaltered cores. Valley of Desolation (VoD) samples have a variety of patterns of alteration, with some clasts a uniform white-orange color, whereas others have variable thicknesses of an altered rind (1-20 mm), with relatively unaltered cores. Multiple hydrothermal minerals precipitated in the outer rinds display distinctive colors, suggestive of sulphides (dark gray), sulphates (orange and yellow), and iron oxides(?) (pink and purple). Cold Soufriere (CS) samples appear to be the most altered, often crumbling at touch. Others had rinds (2-10 mm) and pinkish gray cores that suggest more alteration compared to VoD and SS samples. Preliminary mineral identification of rind compositions was determined by XRD. Scans indicate the presence of silica polymorphs cristobalite and tridymite, as well as pyrite and sulphur. Elemental maps created using a SEM to identify any gradation caused by the elemental leaching and/or precipitation show that the boundaries between the weathering rind and the host rock are distinct. Pyroxenes in the rind are significantly altered and contained gypsum and silica veins, and plagioclase is completely replaced by clay minerals. In the groundmass, there is significant sulphur precipitation, as well as a Ti sulphate/sulfide phase. Additional analysis will allow comparison between the different hydrothermal regions.

  6. [An outbreak of Heliotrope food poisoning, Tadjikistan, November 1992-March 1993].

    PubMed

    Chauvin, P; Dillon, J C; Moren, A

    1994-01-01

    The seeds and roots of Heliotropium lasocarpium, contain a pyrrolizidine alkaloid which causes toxic liver injury and veno-occlusive disease (VOD), characterised by an occlusive lesion of the centrolobular veins of the liver, when consumed by humans. The Farkhar region of Southern Tadjikistan, was blockaded from May to November 1992. This led to a famine and a delay of two months in the wheat harvest. Heliotropium lasocarpium had time to grow in the fields and their seeds were therefore collected with the wheat. The contaminated wheat was distributed to the population, who milled it and made bread. The first case of liver toxicity was six weeks after the first consumption of the contaminated bread. By March 1993, 3,906 cases had been recorded (attack rate = 4%). The attack rate were 0.4%, 5.4%, 4.0%, 2.8% and 1.5% for the less than 1 year, 1-14 years, 15-30 years, 31-50 years and over 50 years age groups respectively. The overall case fatality ratio (CFR) was 1.3% and increased with age from 0 to 5.9% in the same age groups. Two of the ten collective farms represented 83.3% of the cases attack rate of 16.9% and 23.6%. Four stages of illness were defined. Stage I corresponds to abdominal pain, nausea or vomiting, and asthenia. All stage I patients (55.5%) recovered rapidly. Stage II is an association of Stage I and hepatomegalia (29.9%). Stage III includes ascites in addition to these symptoms (13.7%) and stage IV alteration of consciousness (0.9%). The last case was reported on March 4th 1993.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Satellite Soil Moisture and Water Storage Observations Identify Early and Late Season Water Supply Influencing Plant Growth in the Missouri Watershed

    NASA Astrophysics Data System (ADS)

    A, G.; Velicogna, I.; Kimball, J. S.; Du, J.; Kim, Y.; Colliander, A.; Njoku, E. G.

    2017-12-01

    We employ an array of continuously overlapping global satellite sensor observations including combined surface soil moisture (SM) estimates from SMAP, AMSR-E and AMSR-2, GRACE terrestrial water storage (TWS), and satellite precipitation measurements, to characterize seasonal timing and inter-annual variations of the regional water supply pattern and its associated influence on vegetation growth estimates from MODIS enhanced vegetation index (EVI), AMSR-E/2 vegetation optical depth (VOD) and GOME-2 solar-induced florescence (SIF). Satellite SM is used as a proxy of plant-available water supply sensitive to relatively rapid changes in surface condition, GRACE TWS measures seasonal and inter-annual variations in regional water storage, while precipitation measurements represent the direct water input to the analyzed ecosystem. In the Missouri watershed, we find surface SM variations are the dominant factor controlling vegetation growth following the peak of the growing season. Water supply to growth responds to both direct precipitation inputs and groundwater storage carry-over from prior seasons (winter and spring), depending on land cover distribution and regional climatic condition. For the natural grassland in the more arid central and northwest watershed areas, an early season anomaly in precipitation or surface temperature can have a lagged impact on summer vegetation growth by affecting the surface SM and the underlying TWS supplies. For the croplands in the more humid eastern portions of the watershed, the correspondence between surface SM and plant growth weakens. The combination of these complementary remote-sensing observations provides an effective means for evaluating regional variations in the timing and availability of water supply influencing vegetation growth.

  8. Fire and Deforestation Dynamics in South America over the Past 50 Years

    NASA Astrophysics Data System (ADS)

    van Marle, M.; Field, R. D.; van der Werf, G.

    2015-12-01

    Fires play an important role in the Earth system and are one of the major sources of greenhouse gases and aerosols. Satellites have been key to understand their spatial and temporal variability in space and time, but the most frequently used satellite datasets start only in 1995. There are still large uncertainties about the frequency and intensity of fires in the pre-satellite time period, especially in regions with active deforestation, which may have changed dramatically in intensity in the past decades influencing fire dynamics. We used two datasets to extend the record of fires and deforestation in the Amazon region back in time: 1) annual forest loss rates starting in 1990 derived from Vegetation Optical Depth (VOD), which is a satellite-based vegetation product that can be used as proxy for forest loss, and 2) horizontal visibility as proxy for fire emissions, reported by weather stations and airports in the Amazon, which started around 1940, and having widespread coverage since 1973. We show that these datasets overlap with fire emission estimates from the Global Fire Emissions Database (GFED) enabling us to estimate fire emissions over the last 50 years. We will discuss how fires have varied over time in this region with globally significant emissions, how droughts have influenced fire activity and deforestation rates, and what the impact is of land-use change caused by fire on emissions in the Amazon region.

  9. Expectations and Decisions in the Volunteer’s Dilemma: Effects of Social Distance and Social Projection

    PubMed Central

    Krueger, Joachim I.; Ullrich, Johannes; Chen, Leonard J.

    2016-01-01

    In a Volunteer’s Dilemma (VoD) one individual needs to bear a cost so that a public good can be provided. Expectations regarding what others will do play a critical role because they would ideally be negatively correlated with own decisions; yet, a social-projection heuristic generates positive correlations. In a series of 2-person-dilemma studies with over 1,000 participants, we find that expectations are indeed correlated with own choice, and that people tend to volunteer more than game-theoretic benchmarks and their own expectations would allow. We also find strong evidence for a social-distance heuristic, according to which a person’s own probability to volunteer and the expectation that others will volunteer decrease as others become socially more remote. Experimentally induced expectations make opposite behavior more likely, but respondents underweight these expectations. As a result, there is a small but systematic effect of over-volunteering among psychologically close individuals. PMID:28018257

  10. Oospila bulava, a new emerald geometrid moth from South America (Lepidoptera, Geometridae, Geometrinae).

    PubMed

    Lindt, Aare; Viidalepp, Jaan

    2015-12-15

    Warren (1897) described the genus Oospila for Phorodesma trilunaria Guenée, 1857 from Brazil. Prout (1912; 1932-1933) revised the genus, listing 48 species in the first publication and 58 species in the latter one, in Oospila. Cook and Scoble (1995) grouped eight related genera under Oospila, including 73 species and dividing these into 13 species groups. Pitkin (1996) relied on this revision while publishing a monographic review of the Neotropical geometrine genera. Parsons et al. (1999) attributed the same species that in Cook and Scoble (1995) to the genus. Two species are described later (Viidalepp, 2002; Lévèque & Viidalepp, 2015). While revising collections from the Neotropical region during the last decade, the authors of the present article have found several undescribed taxa: cryptic species are frequently overlooked in large-scale works (Vodă et al., 2014). The result of one case study is published in this article. The primary and subsequent descriptions of relevant taxa are consulted.

  11. Drying effects on the antioxidant properties of tomatoes and ginger.

    PubMed

    Gümüşay, Özlem Aktürk; Borazan, Alev Akpınar; Ercal, Nuran; Demirkol, Omca

    2015-04-15

    In this study, the effects of four different drying processes, sun drying (SD), oven drying (OD), vacuum oven drying (VOD) and freeze drying (FD) for tomatoes (Solanum lycopersicum) and ginger (Zingiber officinale) in terms of thiolic and phenolic contents have been studied. Thiol content, total phenolic content (TPC), ascorbic acid (AA) content, and cupric ion reducing antioxidant capacity (CUPRAC) were determined in fresh and dried samples. Glutathione (GSH) and cysteine (Cys) were determined as the thiol contents of tomatoes and ginger. Significant losses were observed in the contents of TPC, AA, GSH and Cys and CUPRAC values in all samples that were dried using the thermal method. There was a statistically significant difference in the losses of the TPC, AA, and thiol contents between the use of thermal drying and freeze drying (except Cys in tomatoes) methods. Freeze dried tomato and ginger samples have been found to have better antioxidant properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Salvage Chemoimmunotherapy With Inotuzumab Ozogamicin Combined With Mini-Hyper-CVD for Patients With Relapsed or Refractory Philadelphia Chromosome-Negative Acute Lymphoblastic Leukemia: A Phase 2 Clinical Trial.

    PubMed

    Jabbour, Elias; Ravandi, Farhad; Kebriaei, Partow; Huang, Xuelin; Short, Nicholas J; Thomas, Deborah; Sasaki, Koji; Rytting, Michael; Jain, Nitin; Konopleva, Marina; Garcia-Manero, Guillermo; Champlin, Richard; Marin, David; Kadia, Tapan; Cortes, Jorge; Estrov, Zeev; Takahashi, Koichi; Patel, Yogin; Khouri, Maria R; Jacob, Jovitta; Garris, Rebecca; O'Brien, Susan; Kantarjian, Hagop

    2018-02-01

    The outcome of patients with relapsed or refractory (R/R) acute lymphoblastic leukemia (ALL) is poor. Inotuzumab ozogamicin, a CD22 monoclonal antibody bound to calicheamicin, has single-agent activity in R/R ALL. To evaluate the efficacy and safety of inotuzumab ozogamicin plus low-intensity chemotherapy in patients with R/R ALL. A single-arm, phase 2 study of adults with R/R B-cell ALL conducted at The University of Texas MD Anderson Cancer Center, Houston. The chemotherapy used was lower intensity than hyper-CVAD (cyclophosphamide, vincristine, doxorubicin [trade name, Adriamycin; Pfizer], and dexamethasone) and is referred to as mini-hyper-CVD (mini-HCVD: cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, and cytarabine at 0.5 g/m2 × 4 doses). Inotuzumab was given on day 3 of the first 4 courses at 1.8 to 1.3 mg/m2 for cycle 1 followed by 1.3 to 1.0 mg/m2 for subsequent cycles. The primary end points were the overall response rate and overall survival (OS). Secondary end points included safety, relapse-free survival (RFS), the rate of allogeneic stem cell transplantation (ASCT), and the minimal residual disease (MRD) negativity rate. Fifty-nine patients (30 women and 29 men) with a median age of 35 years (range, 18-87 years) were treated. Overall, 46 patients (78%) responded, 35 of them (59%) achieving complete response. The overall MRD negativity rate among responders was 82%. Twenty-six patients (44%) received ASCT. Grade 3 to 4 toxic effects included prolonged thrombocytopenia (81%; n = 48), infections (73%; n = 43), and hyperbilirubinemia (14%; n = 8). Veno-occlusive disease (VOD) occurred in 9 patients (15%). With a median follow-up of 24 months, the median RFS and OS were 8 and 11 months, respectively. The 1-year RFS and OS rates were 40% and 46%, respectively. The 1-year OS rates for patients treated in salvage 1, salvage 2, and salvage 3 or beyond were 57%, 26%, and 39%, respectively (P = .03). The combination of inotuzumab with low-intensity mini-HCVD chemotherapy shows encouraging results in R/R ALL. The risk of VOD should be considered carefully in patients with previous liver damage and among transplant candidates. clinicaltrials.gov Identifier: NCT01371630.

  13. Testing and reference model analysis of FTTH system

    NASA Astrophysics Data System (ADS)

    Feng, Xiancheng; Cui, Wanlong; Chen, Ying

    2009-08-01

    With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN , WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network.. Fiber to the Home (FTTH) will be the goal of telecommunications cable broadband access. In accordance with the development trend of telecommunication services, to enhance the capacity of integrated access network, to achieve triple-play (voice, data, image), based on the existing optical Fiber to the curb (FTTC), Fiber To The Zone (FTTZ), Fiber to the Building (FTTB) user optical cable network, the optical fiber can extend to the FTTH system of end-user by using EPON technology. The article first introduced the basic components of FTTH system; and then explain the reference model and reference point for testing of the FTTH system; Finally, by testing connection diagram, the testing process, expected results, primarily analyze SNI Interface Testing, PON interface testing, Ethernet performance testing, UNI interface testing, Ethernet functional testing, PON functional testing, equipment functional testing, telephone functional testing, operational support capability testing and so on testing of FTTH system. ...

  14. Research of application mode for FTTX technology

    NASA Astrophysics Data System (ADS)

    Wang, Zhong; Yun, Xiang; Huang, Wei

    2009-08-01

    With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN, WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network. In this paper, technique theory of EPON is introduced at first. At the same time, MAC frame structure, automatic detection and ranging of MPCP, DBA,and multi-LLID of EPON is analyzed. Then, service development ability, cost advantage and maintenance superiority based on EPON technology are carried out. At last,with Cost comparison between FTTH / FTTB building model and the traditional model, FTTB + LAN mode which is suitable for the newadding residential users in general areas and FTTN + DSL mode which is suitable for the old city and rural access network transformation are built up in detail. And FTTN + DSL project of rural information in rural areas and FTTH broadband HOUSE project on service solutions program are analyzed. comparing to the traditional access technologies, EPON technology has the obvious advantages, such as distance transmission, high or wide band, saving line resources, service abilities, etc. These are the qualities which not only be served for home users, but solve more access problems for us effectively.

  15. Solid organ transplants following hematopoietic stem cell transplant in children.

    PubMed

    Bunin, Nancy; Guzikowski, Virginia; Rand, Elizabeth R; Goldfarb, Samuel; Baluarte, Jorge; Meyers, Kevin; Olthoff, Kim M

    2010-12-01

    SOT may be indicated for a select group of pediatric patients who experience permanent organ failure following HSCT. However, there is limited information available about outcomes. We identified eight children at our center who received an SOT following an HSCT. Patients were six months to 18 yr at HSCT. Diseases for which children underwent HSCT included thalassemia, Wiskott-Aldrich syndrome, Shwachman-Diamond/bone marrow failure, sickle cell disease (SCD), erythropoietic porphyria (EP), ALL, chronic granulomatous disease, and neuroblastoma. Time from HSCT to SOT was 13 days to seven yr (median, 27 months. Lung SOT was performed for two patients with BO, kidney transplants for three patients, and liver transplants for three patients (VOD, chronic GVHD). Seven patients are alive with functioning allografts 6-180 months from SOT. Advances in organ procurement, operative technique, immunosuppressant therapy, and infection control may allow SOT for a select group of patients post-HSCT. However, scarcity of donor organs available in a timely fashion continues to be a limiting factor. Children who have undergone HSCT and develop single organ failure should be considered for an SOT if there is a high likelihood of cure of the primary disease. © 2010 John Wiley & Sons A/S.

  16. Successful treatment with defibrotide for sinusoidal obstruction syndrome after hematopoietic stem cell transplantation.

    PubMed

    Yakushijin, Kimikazu; Matsui, Toshimitsu; Okamura, Atsuo; Yamamoto, Katsuya; Ito, Mitsuhiro; Chihara, Kazuo

    2005-01-01

    Sinusoidal obstruction syndrome (SOS) (formerly known as hepatic veno-occlusive disease (VOD)) is a life-threatening complication subsequent to hematopoietic stem cell transplantation. However, no completely satisfactory strategies for the treatment of SOS have been established yet. Defibrotide is a single-stranded polydeoxyribonucleotide with anti-thrombotic, anti-ischemic, anti-inflammatory and thrombolytic properties, but without systemic anticoagulant effects, and some encouraging results have been reported in western countries. We treated four patients with defibrotide for SOS, since there seemed to be no possibility to cure the patients with conventionally available treatments in Japan. All patients showed evidence of multiple organ failure at the start of the treatment. Defibrotide was administered intravenously in normal saline in four divided doses for 14 to 27 days. Three patients (75%) responded to the therapy, while one died of SOS and cytomegalovirus infection despite intensive therapy. None of the patients suffered from significant adverse effects such as severe hemorrhage. This is the first report dealing with the treatment with defibrotide of Japanese patients with SOS. Because defibrotide is considered to be promising for the treatment of SOS, it is important to start a phase II study as soon as possible.

  17. Dose-Reduced Busulfan, Cyclophosphamide, and Autologous Stem Cell Transplantation for Human Immunodeficiency Virus–Associated Lymphoma: AIDS Malignancy Consortium Study 020

    PubMed Central

    Spitzer, Thomas R.; Ambinder, Richard F.; Lee, Jeannette Y.; Kaplan, Lawrence D.; Wachsman, William; Straus, David J.; Aboulafia, David M.; Scadden, David T.

    2013-01-01

    Intensive chemotherapy for human immunodeficiency virus (HIV)-associated non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) has resulted in durable remissions in a substantial proportion of patients. High-dose chemotherapy and autologous stem cell transplantation (AuSCT), moreover, has resulted in sustained complete remissions in selected patients with recurrent chemosensitive disease. Based on a favorable experience with dose-reduced high-dose busulfan, cyclophosphamide, and AuSCT for older patients with non-HIV–associated aggressive lymphomas, an AIDS Malignancy Consortium multicenter trial was undertaken using the same dose-reduced busulfan and cyclophosphamide preparative regimen with AuSCT for recurrent HIV-associated NHL and HL. Of the 27 patients in the study, 20 received an AuSCT. The median time to achievement of an absolute neutrophil count (ANC) of ≥ 0.5 × 109/L was 11 days (range, 9-16 days). The median time to achievement of an unsupported platelet count of ≥ 20 × 109/L was 13 days (range, 6-57 days). One patient died on day +33 posttransplantation from hepatic veno-occlusive disease (VOD) and multiorgan failure. No other fatal regimen-related toxicity occurred. Ten of 19 patients (53%) were in complete remission at the time of their day +100 post-AuSCT evaluation. Of the 20 patients, 10 were alive and event-free at a median of 23 weeks post-AuSCT. Median overall survival (OS) was not reached by 13 of the 20 patients alive at the time of last follow-up. This multi-institutional trial demonstrates that a regimen of dose-reduced high-dose busulfan, cyclophosphamide, and AuSCT is well tolerated and is associated with favorable disease-free survival (DFS) and OS probabilities for selected patients with HIV-associated NHL and HL. PMID:18158962

  18. A large-scale video codec comparison of x264, x265 and libvpx for practical VOD applications

    NASA Astrophysics Data System (ADS)

    De Cock, Jan; Mavlankar, Aditya; Moorthy, Anush; Aaron, Anne

    2016-09-01

    Over the last years, we have seen exciting improvements in video compression technology, due to the introduction of HEVC and royalty-free coding specifications such as VP9. The potential compression gains of HEVC over H.264/AVC have been demonstrated in different studies, and are usually based on the HM reference software. For VP9, substantial gains over H.264/AVC have been reported in some publications, whereas others reported less optimistic results. Differences in configurations between these publications make it more difficult to assess the true potential of VP9. Practical open-source encoder implementations such as x265 and libvpx (VP9) have matured, and are now showing high compression gains over x264. In this paper, we demonstrate the potential of these encoder imple- mentations, with settings optimized for non-real-time random access, as used in a video-on-demand encoding pipeline. We report results from a large-scale video codec comparison test, which includes x264, x265 and libvpx. A test set consisting of a variety of titles with varying spatio-temporal characteristics from our catalog is used, resulting in tens of millions of encoded frames, hence larger than test sets previously used in the literature. Re- sults are reported in terms of PSNR, SSIM, MS-SSIM, VIF and the recently introduced VMAF quality metric. BD-rate calculations show that using x265 and libvpx vs. x264 can lead to significant bitrate savings for the same quality. x265 outperforms libvpx in most cases, but the performance gap narrows (or even reverses) at the higher resolutions.

  19. Sinusoidal Obstruction Syndrome (Hepatic Veno-Occlusive Disease)

    PubMed Central

    Fan, Cathy Q.; Crawford, James M.

    2014-01-01

    Hepatic sinusoidal obstruction syndrome (SOS) is an obliterative venulitis of the terminal hepatic venules, which in its more severe forms imparts a high risk of mortality. SOS, also known as veno-occlusive disease (VOD), occurs as a result of cytoreductive therapy prior to hematopoietic stem cell transplantation (HSCT), following oxaliplatin-containing adjuvant or neoadjuvant chemotherapy for colorectal carcinoma metastatic to the liver and treated by partial hepatectomy, in patients taking pyrrolizidine alkaloid-containing herbal remedies, and in other particular settings such as the autosomal recessive condition of veno-occlusive disease with immunodeficiency (VODI). A central pathogenic event is toxic destruction of hepatic sinusoidal endothelial cells (SEC), with sloughing and downstream occlusion of terminal hepatic venules. Contributing factors are SEC glutathione depletion, nitric oxide depletion, increased intrahepatic expression of matrix metalloproteinases and vascular endothelial growth factor (VEGF), and activation of clotting factors. The clinical presentation of SOS includes jaundice, development of right upper-quadrant pain and tender hepatomegaly, ascites, and unexplained weight gain. Owing to the potentially critical condition of these patients, transjugular biopsy may be the preferred route for liver biopsy to exclude other potential causes of liver dysfunction and to establish a diagnosis of SOS. Treatment includes rigorous fluid management so as to avoid excessive fluid overload while avoiding too rapid diuresis or pericentesis, potential use of pharmaceutics such as defibrotide, coagulolytic agents, or methylprednisolone, and liver transplantation. Proposed strategies for prevention and prophylaxis include reduced-intensity conditioning radiation for HSCT, treatment with ursodeoxycholic acid, and inclusion of bevacizumab with oxaliplatin-based chemotherapeutic regimes. While significant progress has been made in understanding the pathogenesis of SOS and in mitigating against its adverse outcomes, this condition remains a serious complication of a selective group of medical treatments. PMID:25755580

  20. Assessing change in sensitivity of tropical vegetation to climate based on wavelet analysis

    NASA Astrophysics Data System (ADS)

    Claessen, J.; Martens, B.; Verhoest, N.; Molini, A.; Miralles, D. G.

    2017-12-01

    Vegetation dynamics are driven by climate, and at the same time they play a key role in forcing the different bio-geochemical cycles. As climate change leads to an increase in frequency and intensity of hydro-meteorological extremes, vegetation is expected to respond to these changes, and subsequently feed back on their occurrence. Future responses can be better understood by analysing the past using time series of different vegetation diagnostics observed from space, both in the optical and microwave domain. In this contribution, the climatic drivers (air temperature, precipitation, and incoming radiation) of these different vegetation diagnostics are analysed using a monthly global data-cube of 32 years at a 0.25° resolution. To do so, we analyse the wavelet coherence between each vegetation index and the climatic drivers of vegetation. The use of wavelet coherence allows unveiling the different response and sensitivity of the diverse vegetation indices to their climatic drivers, simultaneously in the time and frequency domains. Our results show that the wavelet-based statistics are suitable for extracting information from the different vegetation indices. Areas of high rainfall volumes are characterised by a strong control of radiation and temperature over vegetation. At higher latitudes, the positive trends in all vegetation diagnostics agree with the hypothesis of a greening pattern, which is coherent with the increase in temperature. At the same time, substantial differences can be observed between the responses of the different vegetation indices as well. As an example, the VOD - thought to be a close proxy for vegetation water content - shows a larger sensitivity to precipitation than traditional optical indices such as the NDVI. Further, important temporal changes in the wavelet coherence between vegetation and climate are identified. For instance, the Amazonian rainforest shows an increased correspondence with precipitation dynamics, indicating positive shifts in ecosystem sensitivity to water availability, which can arguably be related to an increase in the amplitude of the seasonal cycle in rainfall. These results are in line with the expected intensification of the water cycle due to climate change and point to the complex response of the biosphere to climatic changes.

  1. Distinguishing the vegetation dynamics induced by anthropogenic factors using vegetation optical depth and AVHRR NDVI: A cross-border study on the Mongolian Plateau.

    PubMed

    Zhou, Xiang; Yamaguchi, Yasushi; Arjasakusuma, Sanjiwana

    2018-03-01

    Distinguishing the vegetation dynamics induced by anthropogenic factors and identifying the major drivers can provide crucial information for designing actionable and practical countermeasures to restore degraded grassland ecosystems. Based on the residual trend (RESTREND) method, this study distinguished the vegetation dynamics induced by anthropogenic factors from the effects of climate variability on the Mongolian Plateau during 1993-2012 using vegetation optical depth (VOD) and normalized difference vegetation index (NDVI), which measure vegetation water content in aboveground biomass and chlorophyll abundance in canopy cover respectively; afterwards, the major drivers within different agricultural zones and socio-institutional periods were identified by integrating agricultural statistics with statistical analysis techniques. The results showed that grasslands in Mongolia and the grazing zone of Inner Mongolia Autonomous Region (IMAR), China underwent a significant human-induced decrease in aboveground biomass during 1993-2012 and 1993-2000 respectively, which was attributable to the rapid growth of livestock densities stimulated by livestock privatization and market factors; by contrast, grasslands in these two regions did not experience a concurrent human-induced reduction in canopy greenness. Besides, the results indicated that grasslands in the grazing zone of IMAR underwent a significant human-induced increase in aboveground biomass since 2000, which was attributable to the reduced grazing pressure induced by China's ecological restoration programs; concurrently, grasslands in this region also experienced a remarkable increase in canopy greenness, however, this increase was found not directly caused by the decreased stocking densities. Furthermore, the results revealed that the farming and semi-grazing/farming zone of IMAR underwent a significant human-induced increase in both aboveground biomass and canopy greenness since 2000, which was attributable to the intensified grain production stimulated by market factors, open grazing regulation and confined feeding popularization. These findings suggest that China's grassland restoration practice has important implications for Mongolia to reverse the severe and continuous grassland degradation in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Effect of Velocity of Detonation of Explosives on Seismic Radiation

    NASA Astrophysics Data System (ADS)

    Stroujkova, A. F.; Leidig, M.; Bonner, J. L.

    2014-12-01

    We studied seismic body wave generation from four fully contained explosions of approximately the same yields (68 kg of TNT equivalent) conducted in anisotropic granite in Barre, VT. The explosions were detonated using three types of explosives with different velocities of detonation (VOD): Black Powder (BP), Ammonium Nitrate Fuel Oil/Emulsion (ANFO), and Composition B (COMP B). The main objective of the experiment was to study differences in seismic wave generation among different types of explosives, and to determine the mechanism responsible for these differences. The explosives with slow burn rate (BP) produced lower P-wave amplitude and lower corner frequency, which resulted in lower seismic efficiency (0.35%) in comparison with high burn rate explosives (2.2% for ANFO and 3% for COMP B). The seismic efficiency estimates for ANFO and COMP B agree with previous studies for nuclear explosions in granite. The body wave radiation pattern is consistent with an isotropic explosion with an added azimuthal component caused by vertical tensile fractures oriented along pre-existing micro-fracturing in the granite, although the complexities in the P- and S-wave radiation patterns suggest that more than one fracture orientation could be responsible for their generation. High S/P amplitude ratios and low P-wave amplitudes suggest that a significant fraction of the BP source mechanism can be explained by opening of the tensile fractures as a result of the slow energy release.

  3. Regional climate model downscaling may improve the prediction of alien plant species distributions

    NASA Astrophysics Data System (ADS)

    Liu, Shuyan; Liang, Xin-Zhong; Gao, Wei; Stohlgren, Thomas J.

    2014-12-01

    Distributions of invasive species are commonly predicted with species distribution models that build upon the statistical relationships between observed species presence data and climate data. We used field observations, climate station data, and Maximum Entropy species distribution models for 13 invasive plant species in the United States, and then compared the models with inputs from a General Circulation Model (hereafter GCM-based models) and a downscaled Regional Climate Model (hereafter, RCM-based models).We also compared species distributions based on either GCM-based or RCM-based models for the present (1990-1999) to the future (2046-2055). RCM-based species distribution models replicated observed distributions remarkably better than GCM-based models for all invasive species under the current climate. This was shown for the presence locations of the species, and by using four common statistical metrics to compare modeled distributions. For two widespread invasive taxa ( Bromus tectorum or cheatgrass, and Tamarix spp. or tamarisk), GCM-based models failed miserably to reproduce observed species distributions. In contrast, RCM-based species distribution models closely matched observations. Future species distributions may be significantly affected by using GCM-based inputs. Because invasive plants species often show high resilience and low rates of local extinction, RCM-based species distribution models may perform better than GCM-based species distribution models for planning containment programs for invasive species.

  4. Busulfan pharmacokinetics following intravenous and oral dosing regimens in children receiving high-dose myeloablative chemotherapy for high-risk neuroblastoma as part of the HR-NBL-1/SIOPEN trial.

    PubMed

    Veal, G J; Nguyen, L; Paci, A; Riggi, M; Amiel, M; Valteau-Couanet, D; Brock, P; Ladenstein, R; Vassal, G

    2012-11-01

    Busulfan is widely used in a neuroblastoma setting, with several studies reporting marked inter-patient variability in busulfan pharmacokinetics and pharmacodynamics. The current study reports on the pharmacokinetics of oral versus intravenous (IV) busulfan in high-risk neuroblastoma patients treated on the European HR-NBL-1/SIOPEN study. Busulfan was administered four times daily for 4 days to children aged 0.7-13.1 years, either orally (1.45-1.55 mg/kg) or by the IV route (0.8-1.2mg/kg according to body weight strata). Blood samples were obtained prior to administration, 2, 4, and 6h after the start of administration on dose 1. Busulfan analysis was carried out by gas chromatography-mass spectrometry and data analysed using a NONMEM population pharmacokinetic approach. Busulfan plasma concentrations obtained from 38 patients receiving IV busulfan and 25 patients receiving oral busulfan, were fitted simultaneously using a one-compartment pharmacokinetic model. Lower variability in drug exposure was observed following IV administration, with a mean busulfan area under the plasma concentration versus time curve (AUC) of 1146 ± 187 μM.min (range 838-1622), as compared to 953 ± 290 μM.min (range 434-1427) following oral busulfan. A total of 87% of children treated with IV busulfan achieved AUC values within the target of 900-1500 μM.min versus 56% of patients following oral busulfan. Busulfan AUC values were significantly higher in HR-NBL-1/SIOPEN trial patients who experienced hepatic toxicity or veno-occlusive disease (VOD) (1177 ± 189 μM.min versus 913 ± 256 μM.min; p=0.0086). Further stratification based on route of administration suggested that the incidence of hepatic toxicity was related to both high busulfan AUC and oral drug administration. The reduced pharmacokinetic variability and improved control of busulfan AUC observed following IV administration support its utility within the ongoing HR-NBL-1/SIOPEN trial. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Pregnancy and recurrence rates in infertile patients operated for ovarian endometriosis.

    PubMed

    Luţuc, Monica Holicov; Nemescu, D; Onofriescu, Alina; Târnovanu, Mihaela; Moscalu, Mihaela; Onofriescu, M

    2015-01-01

    The study deals with the preoperative ultrasound diagnosis of ovarian endometriosis, postoperative ultrasound reassessment, laparoscopic surgical resolution of ovarian endometriosis, estimation of recurrence risk 12 months after surgery by ultrasound, reappearance of clinical symptoms (such as pain) or second-look laparoscopy, and pregnancy rate 2 years after surgery. 140 patients with en- dometriosis and infertility admitted to the Iasi "Cuza-Vodă" Clinical Hospital of Obstetrics and Gynecology between the years 2009-2011 were included in the study. The patients were divided into 2 groups: group 1-59 cases that refused in vitro fertilization procedures, did not afford in vitro fertilization (IVF) or had minimal endometriosis and young ages and thus a possibility of delaying treatment, and group 2--62 cases which underwent IVF procedures immediately after surgery. No significant differences in the chance of becoming pregnant were found between the two groups (χ2 = 2.06, p = 0.0891, 95% CI); in group 1, 11.86% pregnancies were obtained while in group 2 the pregnancy rate was 11.29%. Based on the nonparametric method of analysis of contingency tables we could estimate the odds of becoming pregnant in the study groups, obtaining an odds ratio (OR = 1.16, CI: 1.04-2.23, 95% CI). This result indicated that in group 1 the odds of becoming pregnant was not significantly higher, and the estimation was made for a confidence interval of 95%. The study had in view the assessment of pregnancies obtained in the study groups and the time interval (number of weeks) from the time of intervention until the occurrence of pregnancy. The Kaplan-Meier analysis enabled the assessment of the mean value and the median value of the number of weeks until becoming pregnant, and these values did not show significant differences (χ2 = 1.55, p = 0.212, 95% CI). For endometriosis associated with infertility, hormonal suppression does not improve fertility, and therefore surgery followed by controlled ovarian hyperstimulation and intrauterine insemi- nation (IUI), provided the anatomy of the pelvis is preserved in early cases or in vitro fertilization in severe cases is preferred.

  6. Transforming for Distribution Based Logistics

    DTIC Science & Technology

    2005-05-26

    distribution process, and extracts elements of distribution and distribution management . Finally characteristics of an effective Army distribution...eventually evolve into a Distribution Management Element. Each organization is examined based on their ability to provide centralized command, with an...distribution and distribution management that together form the distribution system. Clearly all of the physical distribution activities including

  7. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Snelson, C. M., Chipman, V. D., White, R. L., Emmitt, R. F., Townsend, M. J., Barker, D., Lee, P.

    Understanding the changes in seismic energy as it travels from the near field to the far field is the ultimate goal in monitoring for explosive events of interest. This requires a clear understanding of explosion phenomenology as it relates to seismic, infrasound, and acoustic signals. Although there has been much progress in modeling these phenomena, this has been primarily based in the empirical realm. As a result, the logical next step in advancing the seismic monitoring capability of the United States is to conduct field tests that can expand the predictive capability of the physics-based modeling currently under development. Themore » Source Physics Experiment at the Nevada National Security Site (SPE-N) is the first step in this endeavor to link the empirically based with the physics-based modeling. This is a collaborative project between National Security Technologies (NSTec), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), the Defense Threat Reduction Agency (DTRA), and the Air Force Technical Applications Center (AFTAC). The test series require both the simple and complex cases to fully characterize the problem, which is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and how anisotropy controls seismic energy transmission and partitioning. The current series is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the fairly homogenous granite; the location of previous nuclear tests in the same rock body; and generally the geology has been well characterized. The simple geology series is planned for 7 shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD), down-hole accelerometers, surface accelerometers, infrasound, and a suite of seismic sensors of various frequency bands from the near field to the far field. This allows for the use of a single test bed in the simple geology case instead of multiple tests beds to obtain the same results. The shots are planned at various depths to obtain a Green’s function, scaled-depth of burial data, nominal depth of burial data and damage zone data. SPE1-N was conducted in May 2011 as a 220 lb (100 kg) TNT equivalent calibration shot at a depth of 180 ft (55 m). SPE2-N was conducted in October 2011 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m). SPE3-N was conducted in July 2012 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m) in the damaged zone. Over 400 data channels were recorded for each of these shots and data recovery was about 95% with high signal to noise ratio. Once the simple geology site data has been utilized, a new test bed will be developed in a complex geology site to test these physics based models. Ultimately, the results from this project will provide the next advances in the science of monitoring to enable a physics-based predicative capability.« less

  8. Bivariate Rainfall and Runoff Analysis Using Shannon Entropy Theory

    NASA Astrophysics Data System (ADS)

    Rahimi, A.; Zhang, L.

    2012-12-01

    Rainfall-Runoff analysis is the key component for many hydrological and hydraulic designs in which the dependence of rainfall and runoff needs to be studied. It is known that the convenient bivariate distribution are often unable to model the rainfall-runoff variables due to that they either have constraints on the range of the dependence or fixed form for the marginal distributions. Thus, this paper presents an approach to derive the entropy-based joint rainfall-runoff distribution using Shannon entropy theory. The distribution derived can model the full range of dependence and allow different specified marginals. The modeling and estimation can be proceeded as: (i) univariate analysis of marginal distributions which includes two steps, (a) using the nonparametric statistics approach to detect modes and underlying probability density, and (b) fitting the appropriate parametric probability density functions; (ii) define the constraints based on the univariate analysis and the dependence structure; (iii) derive and validate the entropy-based joint distribution. As to validate the method, the rainfall-runoff data are collected from the small agricultural experimental watersheds located in semi-arid region near Riesel (Waco), Texas, maintained by the USDA. The results of unviariate analysis show that the rainfall variables follow the gamma distribution, whereas the runoff variables have mixed structure and follow the mixed-gamma distribution. With this information, the entropy-based joint distribution is derived using the first moments, the first moments of logarithm transformed rainfall and runoff, and the covariance between rainfall and runoff. The results of entropy-based joint distribution indicate: (1) the joint distribution derived successfully preserves the dependence between rainfall and runoff, and (2) the K-S goodness of fit statistical tests confirm the marginal distributions re-derived reveal the underlying univariate probability densities which further assure that the entropy-based joint rainfall-runoff distribution are satisfactorily derived. Overall, the study shows the Shannon entropy theory can be satisfactorily applied to model the dependence between rainfall and runoff. The study also shows that the entropy-based joint distribution is an appropriate approach to capture the dependence structure that cannot be captured by the convenient bivariate joint distributions. Joint Rainfall-Runoff Entropy Based PDF, and Corresponding Marginal PDF and Histogram for W12 Watershed The K-S Test Result and RMSE on Univariate Distributions Derived from the Maximum Entropy Based Joint Probability Distribution;

  9. Predicting fundamental and realized distributions based on thermal niche: A case study of a freshwater turtle

    NASA Astrophysics Data System (ADS)

    Rodrigues, João Fabrício Mota; Coelho, Marco Túlio Pacheco; Ribeiro, Bruno R.

    2018-04-01

    Species distribution models (SDM) have been broadly used in ecology to address theoretical and practical problems. Currently, there are two main approaches to generate SDMs: (i) correlative, which is based on species occurrences and environmental predictor layers and (ii) process-based models, which are constructed based on species' functional traits and physiological tolerances. The distributions estimated by each approach are based on different components of species niche. Predictions of correlative models approach species realized niches, while predictions of process-based are more akin to species fundamental niche. Here, we integrated the predictions of fundamental and realized distributions of the freshwater turtle Trachemys dorbigni. Fundamental distribution was estimated using data of T. dorbigni's egg incubation temperature, and realized distribution was estimated using species occurrence records. Both types of distributions were estimated using the same regression approaches (logistic regression and support vector machines), both considering macroclimatic and microclimatic temperatures. The realized distribution of T. dorbigni was generally nested in its fundamental distribution reinforcing theoretical assumptions that the species' realized niche is a subset of its fundamental niche. Both modelling algorithms produced similar results but microtemperature generated better results than macrotemperature for the incubation model. Finally, our results reinforce the conclusion that species realized distributions are constrained by other factors other than just thermal tolerances.

  10. A distributed data base management system. [for Deep Space Network

    NASA Technical Reports Server (NTRS)

    Bryan, A. I.

    1975-01-01

    Major system design features of a distributed data management system for the NASA Deep Space Network (DSN) designed for continuous two-way deep space communications are described. The reasons for which the distributed data base utilizing third-generation minicomputers is selected as the optimum approach for the DSN are threefold: (1) with a distributed master data base, valid data is available in real-time to support DSN management activities at each location; (2) data base integrity is the responsibility of local management; and (3) the data acquisition/distribution and processing power of a third-generation computer enables the computer to function successfully as a data handler or as an on-line process controller. The concept of the distributed data base is discussed along with the software, data base integrity, and hardware used. The data analysis/update constraint is examined.

  11. A Multi-level Fuzzy Evaluation Method for Smart Distribution Network Based on Entropy Weight

    NASA Astrophysics Data System (ADS)

    Li, Jianfang; Song, Xiaohui; Gao, Fei; Zhang, Yu

    2017-05-01

    Smart distribution network is considered as the future trend of distribution network. In order to comprehensive evaluate smart distribution construction level and give guidance to the practice of smart distribution construction, a multi-level fuzzy evaluation method based on entropy weight is proposed. Firstly, focus on both the conventional characteristics of distribution network and new characteristics of smart distribution network such as self-healing and interaction, a multi-level evaluation index system which contains power supply capability, power quality, economy, reliability and interaction is established. Then, a combination weighting method based on Delphi method and entropy weight method is put forward, which take into account not only the importance of the evaluation index in the experts’ subjective view, but also the objective and different information from the index values. Thirdly, a multi-level evaluation method based on fuzzy theory is put forward. Lastly, an example is conducted based on the statistical data of some cites’ distribution network and the evaluation method is proved effective and rational.

  12. Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for High-Grade Gliomas in Children and Adolescents

    PubMed Central

    2017-01-01

    With the aim to investigate the outcome of tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) for high-grade gliomas (HGGs), we retrospectively reviewed the medical records of 30 patients with HGGs (16 glioblastomas, 7 anaplastic astrocytomas, and 7 other HGGs) between 2006 and 2015. Gross or near total resection was possible in 11 patients. Front-line treatment after surgery was radiotherapy (RT) in 14 patients and chemotherapy in the remaining 16 patients including 3 patients less than 3 years of age. Eight of 12 patients who remained progression free and 5 of the remaining 18 patients who experienced progression during induction treatment underwent the first HDCT/auto-SCT with carboplatin + thiotepa + etoposide (CTE) regimen and 11 of them proceeded to the second HDCT/auto-SCT with cyclophosphamide + melphalan (CyM) regimen. One patient died from hepatic veno-occlusive disease (VOD) during the second HDCT/auto-SCT; otherwise, toxicities were manageable. Four patients in complete response (CR) and 3 of 7 patients in partial response (PR) or second PR at the first HDCT/auto-SCT remained event free: however, 2 patients with progressive tumor experienced progression again. The probabilities of 3-year overall survival (OS) after the first HDCT/auto-SCT in 11 patients in CR, PR, or second PR was 58.2% ± 16.9%. Tumor status at the first HDCT/auto-SCT was the only significant factor for outcome after HDCT/auto-SCT. There was no difference in survival between glioblastoma and other HGGs. This study suggests that the outcome of HGGs in children and adolescents after HDCT/auto-SCT is encouraging if the patient could achieve CR or PR before HDCT/auto-SCT. PMID:28049229

  13. Preclinical Studies in Support of Defibrotide for the Treatment of Multiple Myeloma and Other Neoplasias

    PubMed Central

    Mitsiades, Constantine S.; Rouleau, Cecile; Echart, Cinara; Menon, Krishna; Teicher, Beverly; Distaso, Maria; Palumbo, Antonio; Boccadoro, Mario; Anderson, Kenneth C.; Iacobelli, Massimo; Richardson, Paul G.

    2015-01-01

    Purpose of the study Defibrotide (DF), an orally bioavailable polydisperse oligonucleotide has promising activity in hepatic veno-occlusive disease (VOD), a stem cell transplantation-related toxicity, characterized by microangiopathy. The anti-thrombotic properties of DF and its minimal hemorrhagic risk could serve for treatment of cancer-associated thrombotic complications. Given its cytoprotective effect on endothelium, we investigated whether DF protects tumor cells from cytotoxic anti-tumor agents. Further, given its anti-adhesive properties, we evaluated whether DF modulates the protection conferred to multiple myeloma (MM) cells by bone marrow stromal cells (BMSCs). Methods-Results DF lacks significant single-agent in vitro cytotoxicity on MM or solid tumor cells and does not attenuate their in vitro response to dexamethasone, bortezomib, immunomodulatory thalidomide derivatives, and conventional chemotherapeutics, including melphalan and cyclophosphamide. Importantly, DF enhances in vivo chemosensitivity of MM and mammary carcinoma xenografts in animal models. In co-cultures of MM cells with BMSCs in vitro, DF enhances the MM cell sensitivity to melphalan and dexamethasone, decreases MM-BMSC adhesion and its sequelae, including NF-κB activation in MM and BMSCs, and associated cytokine production. Moreover, DF inhibits expression and/or function of key mediators of MM interaction with BMSC and endothelium, including heparanase, angiogenic cytokines and adhesion molecules. Conclusion Defibrotide’s in vivo chemosensitizing properties and lack of direct in vitro activity against tumor cells suggest that it favorably modulates antitumor interactions between BMSC and endothelia in the tumor microenvironment. These data support clinical studies of DF in combination with conventional and novel therapies to potentially improve patient outcome in MM and other malignancies. PMID:19228727

  14. Investigation of targeted pyrrolizidine alkaloids in traditional Chinese medicines and selected herbal teas sourced in Ireland using LC-ESI-MS/MS.

    PubMed

    Griffin, Caroline T; Gosetto, Francesca; Danaher, Martin; Sabatini, Stefano; Furey, Ambrose

    2014-01-01

    Publications linking hepatotoxicity to the use of herbal preparations are escalating. Herbal teas, traditional Chinese medicines (TCMs) and dietary supplements have been shown to contain pyrrolizidine alkaloids (PAs). Acute PA toxicosis of the liver can result in sinusoidal-obstruction syndrome, also known as veno-occlusive disease (VOD). This paper describes a sensitive and robust method for the detection of targeted PAs and their N-oxides (PANOs) in herbal products (selected herbal teas and TCMs) sourced within Ireland. The sample preparation includes a simple acidic extraction with clean-up via solid-phase extraction (SPE). Sample extracts were accurately analysed by using LC-ESI-MS/MS applying for the first time a pentafluorophenyl (PFP) core-shell column to the chromatographic separation of PAs and PANOs. The method was validated for selectivity, taking into consideration matrix effects, specificity, linearity, precision and trueness. Limits of detection (LOD) and limits of quantitation (LOQ) were quantified for all PAs and PANOs ranging from 0.4 to 1.9 µg kg⁻¹ and from 1.3 to 6.3 µg kg⁻¹, respectively. In this study 10 PAs and four PANOs were targeted because they are commercially available as reference standards. Therefore, this study can only report the levels of these PAs and PANOs analysed in the herbal teas and TCMs. The results reported represent the minimum levels of PAs and PANOs present in the samples analysed; commercially available herbal teas (n = 18) and TCMs (n = 54). A total of 50% herbal teas and 78% Chinese medicines tested positive for one or more PAs and/or PANOs included within this study, ranging from 10 to 1733 and from 13 to 3668 µg kg⁻¹, respectively.

  15. Brain potentials predict substance abuse treatment completion in a prison sample.

    PubMed

    Fink, Brandi C; Steele, Vaughn R; Maurer, Michael J; Fede, Samantha J; Calhoun, Vince D; Kiehl, Kent A

    2016-08-01

    National estimates suggest that up to 80% of prison inmates meet diagnostic criteria for a substance use disorder. Because more substance abuse treatment while incarcerated is associated with better post-release outcomes, including a reduced risk of accidental overdose death, the stakes are high in developing novel predictors of substance abuse treatment completion in inmate populations. Using electroencephalography (EEG), this study investigated stimulus-locked ERP components elicited by distractor stimuli in three tasks (VO-Distinct, VO-Repeated, Go/NoGo) as a predictor of treatment discontinuation in a sample of male and female prison inmates. We predicted that those who discontinued treatment early would exhibit a less positive P3a amplitude elicited by distractor stimuli. Our predictions regarding ERP components were partially supported. Those who discontinued treatment early exhibited a less positive P3a amplitude and a less positive PC4 in the VO-D task. In the VO-R task, however, those who discontinued treatment early exhibited a more negative N200 amplitude rather than the hypothesized less positive P3a amplitude. The discontinuation group also displayed less positive PC4 amplitude. Surprisingly, there were no time-domain or principle component differences among the groups in the Go/NoGo task. Support Vector Machine (SVM) models of the three tasks accurately classified individuals who discontinued treatment with the best model accurately classifying 75% of inmates. PCA techniques were more sensitive in differentiating groups than the classic time-domain windowed approach. Our pattern of findings are consistent with the context-updating theory of P300 and may help identify subtypes of ultrahigh-risk substance abusers who need specialized treatment programs.

  16. 45 CFR 2516.600 - How are funds for school-based service-learning programs distributed?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false How are funds for school-based service-learning... (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE SCHOOL-BASED SERVICE-LEARNING PROGRAMS Distribution of Funds § 2516.600 How are funds for school-based service-learning programs distributed? (a) Of...

  17. 45 CFR 2516.600 - How are funds for school-based service-learning programs distributed?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false How are funds for school-based service-learning... (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE SCHOOL-BASED SERVICE-LEARNING PROGRAMS Distribution of Funds § 2516.600 How are funds for school-based service-learning programs distributed? (a) Of...

  18. 45 CFR 2517.600 - How are funds for community-based service-learning programs distributed?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false How are funds for community-based service-learning... (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE COMMUNITY-BASED SERVICE-LEARNING PROGRAMS Distribution of Funds § 2517.600 How are funds for community-based service-learning programs distributed? All...

  19. 45 CFR 2517.600 - How are funds for community-based service-learning programs distributed?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false How are funds for community-based service-learning... (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE COMMUNITY-BASED SERVICE-LEARNING PROGRAMS Distribution of Funds § 2517.600 How are funds for community-based service-learning programs distributed? All...

  20. Ship Detection in SAR Image Based on the Alpha-stable Distribution

    PubMed Central

    Wang, Changcheng; Liao, Mingsheng; Li, Xiaofeng

    2008-01-01

    This paper describes an improved Constant False Alarm Rate (CFAR) ship detection algorithm in spaceborne synthetic aperture radar (SAR) image based on Alpha-stable distribution model. Typically, the CFAR algorithm uses the Gaussian distribution model to describe statistical characteristics of a SAR image background clutter. However, the Gaussian distribution is only valid for multilook SAR images when several radar looks are averaged. As sea clutter in SAR images shows spiky or heavy-tailed characteristics, the Gaussian distribution often fails to describe background sea clutter. In this study, we replace the Gaussian distribution with the Alpha-stable distribution, which is widely used in impulsive or spiky signal processing, to describe the background sea clutter in SAR images. In our proposed algorithm, an initial step for detecting possible ship targets is employed. Then, similar to the typical two-parameter CFAR algorithm, a local process is applied to the pixel identified as possible target. A RADARSAT-1 image is used to validate this Alpha-stable distribution based algorithm. Meanwhile, known ship location data during the time of RADARSAT-1 SAR image acquisition is used to validate ship detection results. Validation results show improvements of the new CFAR algorithm based on the Alpha-stable distribution over the CFAR algorithm based on the Gaussian distribution. PMID:27873794

  1. ProbOnto: ontology and knowledge base of probability distributions.

    PubMed

    Swat, Maciej J; Grenon, Pierre; Wimalaratne, Sarala

    2016-09-01

    Probability distributions play a central role in mathematical and statistical modelling. The encoding, annotation and exchange of such models could be greatly simplified by a resource providing a common reference for the definition of probability distributions. Although some resources exist, no suitably detailed and complex ontology exists nor any database allowing programmatic access. ProbOnto, is an ontology-based knowledge base of probability distributions, featuring more than 80 uni- and multivariate distributions with their defining functions, characteristics, relationships and re-parameterization formulas. It can be used for model annotation and facilitates the encoding of distribution-based models, related functions and quantities. http://probonto.org mjswat@ebi.ac.uk Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

  2. Design and implementation of a distributed large-scale spatial database system based on J2EE

    NASA Astrophysics Data System (ADS)

    Gong, Jianya; Chen, Nengcheng; Zhu, Xinyan; Zhang, Xia

    2003-03-01

    With the increasing maturity of distributed object technology, CORBA, .NET and EJB are universally used in traditional IT field. However, theories and practices of distributed spatial database need farther improvement in virtue of contradictions between large scale spatial data and limited network bandwidth or between transitory session and long transaction processing. Differences and trends among of CORBA, .NET and EJB are discussed in details, afterwards the concept, architecture and characteristic of distributed large-scale seamless spatial database system based on J2EE is provided, which contains GIS client application, web server, GIS application server and spatial data server. Moreover the design and implementation of components of GIS client application based on JavaBeans, the GIS engine based on servlet, the GIS Application server based on GIS enterprise JavaBeans(contains session bean and entity bean) are explained.Besides, the experiments of relation of spatial data and response time under different conditions are conducted, which proves that distributed spatial database system based on J2EE can be used to manage, distribute and share large scale spatial data on Internet. Lastly, a distributed large-scale seamless image database based on Internet is presented.

  3. A New Harmonized Approach to Estimate Busulfan Exposure Predicts Survival and Toxicity after Hematopoietic Cell Transplantation in Children and Young Adults: a Multicenter Retrospective Cohort Analysis

    PubMed Central

    Bartelink, I.H.; Lalmohamed, Arief; van Reij, Elisabeth M.L.; Dvorak, Chris C.; Savic, Rada M.; Zwaveling, Juliette; Bredius, Robbert. G.M.; Egberts, Antoine C.G.; Bierings, M.; Kletzel, M.; Shaw, Peter J.; Nath, Christa E.; Hempel, George; Ansari, M.; Krajinovic, M.; Theoret, Yves; Duval, Michel; Keizer, Ron J.; Bittencourt, Henriette; Hassan, Moustapha; Güngör, Tayfun; Wynn, Robert F.; Veys, Paul; Cuvelier, Geoff D.E.; Marktel, Sarah; Chiesa, Robert; Cowan, Morton J.; Slatter, Mary A.; Stricherz, Melisa K.; Jennissen, Cathryn; Long-Boyle, Janel R.; Boelens, Jaap Jan

    2016-01-01

    Background Intravenous-busulfan (IV-busulfan) combined with therapeutic drug monitoring to guide dosing improves outcomes after allogeneic hematopoietic cell transplantation (allo-HCT). The best method to estimate busulfan exposure and the optimal exposure in children/young adults remains unclear. We therefore evaluated three approaches to estimate IV-Bu exposure (expressed as cumulative-area-under-the-curve; AUC) and associated busulfan-AUC with clinical outcomes in children/young adults undergoing allo-HCT. Methods In this retrospective analysis, patients (0.1–30.4 years) receiving busulfan-based conditioning regimen from 15 centers were included. Cumulative AUC was calculated by numerical integration using non-linear mixed effect modeling (AUCNONMEM), non-compartmental analysis (AUC0-infinity and AUC to the end of the dose interval AUC0-tau) and by individual centers using a variety of approaches (AUCcenter). Main outcome of interest was event-free survival (EFS). Other outcomes of interest were overall survival, graft-failure, relapse, transplantation related mortality (TRM), acute toxicity (veno-occlusive disease (VOD) and/or acute graft versus-host disease (aGvHD), chronic GvHD (cGvHD) and cGVHD-free event-free survival (GEFS). Propensity score adjusted cox proportional hazard models, Weibull models, and Fine-Gray competing risk regressions were used. Results 674 patients were included (41% malignant, 59% non-malignant) Estimated 2-year EFS was 69.7%. The median busulfan AUCNONMEM was 74.4 mg*h/L (CI95% 31.1–104.6 mg*h/L). The median AUCNONMEM correlated poorly with AUCcenter (R2 = 0.254). Patients with optimal IV-busulfan AUC of 78–101 mg*h/L showed 81% EFS at 2 years compared to 66.1% and 49.5% in the low (<78 mg*h/L) and high (>101 mg*h/L) busulfan AUC group respectively (P=0.011). Graft-failure/relapse occurred more frequently in the low AUC group (HR=1.75 P<0.001). Acute toxicity, cGvHD and TRM was significantly higher in the high AUC group (HR 1.69, 2.99 and 1.30), independent of indication. Interpretation These results demonstrate that improved clinical outcomes may be achieved by targeting the busulfan-AUC to 78–101 mg*h/L using a new validated pharmacokinetic-model for all indications. PMID:27746112

  4. A Variance Distribution Model of Surface EMG Signals Based on Inverse Gamma Distribution.

    PubMed

    Hayashi, Hideaki; Furui, Akira; Kurita, Yuichi; Tsuji, Toshio

    2017-11-01

    Objective: This paper describes the formulation of a surface electromyogram (EMG) model capable of representing the variance distribution of EMG signals. Methods: In the model, EMG signals are handled based on a Gaussian white noise process with a mean of zero for each variance value. EMG signal variance is taken as a random variable that follows inverse gamma distribution, allowing the representation of noise superimposed onto this variance. Variance distribution estimation based on marginal likelihood maximization is also outlined in this paper. The procedure can be approximated using rectified and smoothed EMG signals, thereby allowing the determination of distribution parameters in real time at low computational cost. Results: A simulation experiment was performed to evaluate the accuracy of distribution estimation using artificially generated EMG signals, with results demonstrating that the proposed model's accuracy is higher than that of maximum-likelihood-based estimation. Analysis of variance distribution using real EMG data also suggested a relationship between variance distribution and signal-dependent noise. Conclusion: The study reported here was conducted to examine the performance of a proposed surface EMG model capable of representing variance distribution and a related distribution parameter estimation method. Experiments using artificial and real EMG data demonstrated the validity of the model. Significance: Variance distribution estimated using the proposed model exhibits potential in the estimation of muscle force. Objective: This paper describes the formulation of a surface electromyogram (EMG) model capable of representing the variance distribution of EMG signals. Methods: In the model, EMG signals are handled based on a Gaussian white noise process with a mean of zero for each variance value. EMG signal variance is taken as a random variable that follows inverse gamma distribution, allowing the representation of noise superimposed onto this variance. Variance distribution estimation based on marginal likelihood maximization is also outlined in this paper. The procedure can be approximated using rectified and smoothed EMG signals, thereby allowing the determination of distribution parameters in real time at low computational cost. Results: A simulation experiment was performed to evaluate the accuracy of distribution estimation using artificially generated EMG signals, with results demonstrating that the proposed model's accuracy is higher than that of maximum-likelihood-based estimation. Analysis of variance distribution using real EMG data also suggested a relationship between variance distribution and signal-dependent noise. Conclusion: The study reported here was conducted to examine the performance of a proposed surface EMG model capable of representing variance distribution and a related distribution parameter estimation method. Experiments using artificial and real EMG data demonstrated the validity of the model. Significance: Variance distribution estimated using the proposed model exhibits potential in the estimation of muscle force.

  5. Derivation of low flow frequency distributions under human activities and its implications

    NASA Astrophysics Data System (ADS)

    Gao, Shida; Liu, Pan; Pan, Zhengke; Ming, Bo; Guo, Shenglian; Xiong, Lihua

    2017-06-01

    Low flow, refers to a minimum streamflow in dry seasons, is crucial to water supply, agricultural irrigation and navigation. Human activities, such as groundwater pumping, influence low flow severely. In order to derive the low flow frequency distribution functions under human activities, this study incorporates groundwater pumping and return flow as variables in the recession process. Steps are as follows: (1) the original low flow without human activities is assumed to follow a Pearson type three distribution, (2) the probability distribution of climatic dry spell periods is derived based on a base flow recession model, (3) the base flow recession model is updated under human activities, and (4) the low flow distribution under human activities is obtained based on the derived probability distribution of dry spell periods and the updated base flow recession model. Linear and nonlinear reservoir models are used to describe the base flow recession, respectively. The Wudinghe basin is chosen for the case study, with daily streamflow observations during 1958-2000. Results show that human activities change the location parameter of the low flow frequency curve for the linear reservoir model, while alter the frequency distribution function for the nonlinear one. It is indicated that alter the parameters of the low flow frequency distribution is not always feasible to tackle the changing environment.

  6. Integrating DNA-based data into bioassessments improves our understanding of species distributions and species habitat relationships

    EPA Science Inventory

    The integration of DNA-based identification methods into bioassessments could result in more accurate representations of species distributions and species-habitat relationships. DNA-based approaches may be particularly informative for tracking the distributions of rare and/or inv...

  7. Research on Three-phase Four-wire Inverter

    NASA Astrophysics Data System (ADS)

    Xin, W. D.; Li, X. K.; Huang, G. Z.; Fan, X. C.; Gong, X. J.; Sun, L.; Wang, J.; Zhu, D. W.

    2017-05-01

    The concept of Voltage Source Converter (VSC) based hybrid AC and DC distribution system architecture is proposed, which can solve the traditional AC distribution power quality problems and respond to the request of DC distribution development. At first, a novel VSC system structure combining the four-leg based three-phase four-wire with LC filter is adopted, using the overall coordination control scheme of the AC current tracking compensation based grid-interfaced VSC. In the end, the 75 kW simulation experimental system is designed and tested to verify the performance of the proposed VSC under DC distribution, distributed DC sources conditions, as well as power quality management of AC distribution.

  8. Entropy-based goodness-of-fit test: Application to the Pareto distribution

    NASA Astrophysics Data System (ADS)

    Lequesne, Justine

    2013-08-01

    Goodness-of-fit tests based on entropy have been introduced in [13] for testing normality. The maximum entropy distribution in a class of probability distributions defined by linear constraints induces a Pythagorean equality between the Kullback-Leibler information and an entropy difference. This allows one to propose a goodness-of-fit test for maximum entropy parametric distributions which is based on the Kullback-Leibler information. We will focus on the application of the method to the Pareto distribution. The power of the proposed test is computed through Monte Carlo simulation.

  9. Bayesian alternative to the ISO-GUM's use of the Welch Satterthwaite formula

    NASA Astrophysics Data System (ADS)

    Kacker, Raghu N.

    2006-02-01

    In certain disciplines, uncertainty is traditionally expressed as an interval about an estimate for the value of the measurand. Development of such uncertainty intervals with a stated coverage probability based on the International Organization for Standardization (ISO) Guide to the Expression of Uncertainty in Measurement (GUM) requires a description of the probability distribution for the value of the measurand. The ISO-GUM propagates the estimates and their associated standard uncertainties for various input quantities through a linear approximation of the measurement equation to determine an estimate and its associated standard uncertainty for the value of the measurand. This procedure does not yield a probability distribution for the value of the measurand. The ISO-GUM suggests that under certain conditions motivated by the central limit theorem the distribution for the value of the measurand may be approximated by a scaled-and-shifted t-distribution with effective degrees of freedom obtained from the Welch-Satterthwaite (W-S) formula. The approximate t-distribution may then be used to develop an uncertainty interval with a stated coverage probability for the value of the measurand. We propose an approximate normal distribution based on a Bayesian uncertainty as an alternative to the t-distribution based on the W-S formula. A benefit of the approximate normal distribution based on a Bayesian uncertainty is that it greatly simplifies the expression of uncertainty by eliminating altogether the need for calculating effective degrees of freedom from the W-S formula. In the special case where the measurand is the difference between two means, each evaluated from statistical analyses of independent normally distributed measurements with unknown and possibly unequal variances, the probability distribution for the value of the measurand is known to be a Behrens-Fisher distribution. We compare the performance of the approximate normal distribution based on a Bayesian uncertainty and the approximate t-distribution based on the W-S formula with respect to the Behrens-Fisher distribution. The approximate normal distribution is simpler and better in this case. A thorough investigation of the relative performance of the two approximate distributions would require comparison for a range of measurement equations by numerical methods.

  10. Molecular Isotopic Distribution Analysis (MIDAs) with Adjustable Mass Accuracy

    NASA Astrophysics Data System (ADS)

    Alves, Gelio; Ogurtsov, Aleksey Y.; Yu, Yi-Kuo

    2014-01-01

    In this paper, we present Molecular Isotopic Distribution Analysis (MIDAs), a new software tool designed to compute molecular isotopic distributions with adjustable accuracies. MIDAs offers two algorithms, one polynomial-based and one Fourier-transform-based, both of which compute molecular isotopic distributions accurately and efficiently. The polynomial-based algorithm contains few novel aspects, whereas the Fourier-transform-based algorithm consists mainly of improvements to other existing Fourier-transform-based algorithms. We have benchmarked the performance of the two algorithms implemented in MIDAs with that of eight software packages (BRAIN, Emass, Mercury, Mercury5, NeutronCluster, Qmass, JFC, IC) using a consensus set of benchmark molecules. Under the proposed evaluation criteria, MIDAs's algorithms, JFC, and Emass compute with comparable accuracy the coarse-grained (low-resolution) isotopic distributions and are more accurate than the other software packages. For fine-grained isotopic distributions, we compared IC, MIDAs's polynomial algorithm, and MIDAs's Fourier transform algorithm. Among the three, IC and MIDAs's polynomial algorithm compute isotopic distributions that better resemble their corresponding exact fine-grained (high-resolution) isotopic distributions. MIDAs can be accessed freely through a user-friendly web-interface at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/midas/index.html.

  11. Molecular Isotopic Distribution Analysis (MIDAs) with adjustable mass accuracy.

    PubMed

    Alves, Gelio; Ogurtsov, Aleksey Y; Yu, Yi-Kuo

    2014-01-01

    In this paper, we present Molecular Isotopic Distribution Analysis (MIDAs), a new software tool designed to compute molecular isotopic distributions with adjustable accuracies. MIDAs offers two algorithms, one polynomial-based and one Fourier-transform-based, both of which compute molecular isotopic distributions accurately and efficiently. The polynomial-based algorithm contains few novel aspects, whereas the Fourier-transform-based algorithm consists mainly of improvements to other existing Fourier-transform-based algorithms. We have benchmarked the performance of the two algorithms implemented in MIDAs with that of eight software packages (BRAIN, Emass, Mercury, Mercury5, NeutronCluster, Qmass, JFC, IC) using a consensus set of benchmark molecules. Under the proposed evaluation criteria, MIDAs's algorithms, JFC, and Emass compute with comparable accuracy the coarse-grained (low-resolution) isotopic distributions and are more accurate than the other software packages. For fine-grained isotopic distributions, we compared IC, MIDAs's polynomial algorithm, and MIDAs's Fourier transform algorithm. Among the three, IC and MIDAs's polynomial algorithm compute isotopic distributions that better resemble their corresponding exact fine-grained (high-resolution) isotopic distributions. MIDAs can be accessed freely through a user-friendly web-interface at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/midas/index.html.

  12. Recommendations for scale-up of community-based misoprostol distribution programs.

    PubMed

    Robinson, Nuriya; Kapungu, Chisina; Carnahan, Leslie; Geller, Stacie

    2014-06-01

    Community-based distribution of misoprostol for prevention of postpartum hemorrhage (PPH) in resource-poor settings has been shown to be safe and effective. However, global recommendations for prenatal distribution and monitoring within a community setting are not yet available. In order to successfully translate misoprostol and PPH research into policy and practice, several critical points must be considered. A focus on engaging the community, emphasizing the safe nature of community-based misoprostol distribution, supply chain management, effective distribution, coverage, and monitoring plans are essential elements to community-based misoprostol program introduction, expansion, or scale-up. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  13. A Story-Based Simulation for Teaching Sampling Distributions

    ERIC Educational Resources Information Center

    Turner, Stephen; Dabney, Alan R.

    2015-01-01

    Statistical inference relies heavily on the concept of sampling distributions. However, sampling distributions are difficult to teach. We present a series of short animations that are story-based, with associated assessments. We hope that our contribution can be useful as a tool to teach sampling distributions in the introductory statistics…

  14. 2014 Distributed Wind Market Report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Orell, A.; Foster, N.

    2015-08-01

    The cover of the 2014 Distributed Wind Market Report.According to the 2014 Distributed Wind Market Report, distributed wind reached a cumulative capacity of almost 1 GW (906 MW) in the United States in 2014, reflecting nearly 74,000 wind turbines deployed across all 50 states, Puerto Rico, and the U.S. Virgin Islands. In total, 63.6 MW of new distributed wind capacity was added in 2014, representing nearly 1,700 units and $170 million in investment across 24 states. In 2014, America's distributed wind energy industry supported a growing domestic industrial base as exports from United States-based small wind turbine manufacturers accounted formore » nearly 80% of United States-based manufacturers' sales.« less

  15. Problem-Based Learning and Problem-Solving Tools: Synthesis and Direction for Distributed Education Environments.

    ERIC Educational Resources Information Center

    Friedman, Robert S.; Deek, Fadi P.

    2002-01-01

    Discusses how the design and implementation of problem-solving tools used in programming instruction are complementary with both the theories of problem-based learning (PBL), including constructivism, and the practices of distributed education environments. Examines how combining PBL, Web-based distributed education, and a problem-solving…

  16. The Source Physics Experiments (SPE) at the Nevada National Security Site (NNSS): An Overview

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Chipman, V.; White, R. L.; Emmitt, R.; Townsend, M.; Barker, D.; Lee, P.

    2012-12-01

    Understanding the changes in seismic energy as it travels from the near field to the far field is the ultimate goal in monitoring for explosive events of interest. This requires a clear understanding of explosion phenomenology as it relates to seismic, infrasound, and acoustic signals. Although there has been much progress in modeling these phenomena, this has been primarily based in the empirical realm. As a result, the logical next step in advancing the seismic monitoring capability of the United States is to conduct field tests that can expand the predictive capability of the physics-based modeling currently under development. The Source Physics Experiment at the Nevada National Security Site (SPE) is the first step in this endeavor to link the empirically based with the physics-based modeling. This is a collaborative project between National Security Technologies (NSTec), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), the Defense Threat Reduction Agency (DTRA), and the Air Force Technical Applications Center (AFTAC). The test series require both the simple and complex cases to fully characterize the problem, which is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and how anisotropy controls seismic energy transmission and partitioning. The current series is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the fairly homogenous granite; the location of previous nuclear tests in the same rock body; and generally the geology has been well characterized. The simple geology series is planned for 7 shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD), down-hole accelerometers, surface accelerometers, infrasound, and a suite of seismic sensors of various frequency bands from the near field to the far field. This allows for the use of a single test bed in the simple geology case instead of multiple tests beds to obtain the same results. The shots are planned at various depths to obtain a Green's function, scaled-depth of burial data, nominal depth of burial data and damage zone data. SPE1 was conducted in May 2011 as a 220 lb (100 kg) TNT equivalent calibration shot at a depth of 180 ft (55 m). SPE2 was conducted in October 2011 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m). SPE3 was conducted in July 2012 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m) in the damaged zone. Over 400 data channels were recorded for each of these shots and data recovery was about 95% with high signal to noise ratio. Once the simple geology site data has been utilized, a new test bed will be developed in a complex geology site to test these physics based models. Ultimately, the results from this project will provide the next advances in the science of monitoring to enable a physics-based predicative capability. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946--1584

  17. Evaluation of a Delay-Doppler Imaging Algorithm Based on the Wigner-Ville Distribution

    DTIC Science & Technology

    1989-10-18

    exchanging the frequency and time variables. 2.3 PROPERTIES OF THE WIGNER - VILLE DISTRIBUTION A partial list of the properties of the WVD is provided...ESD-TH-89-163 N Technical Report (N R55 00 Lfl Evaluation of a Delay-Doppler Imaging Algorithm Based on the Wigner - Ville Distribution K.I. Schultz 18...DOPPLER IMAGING ALGORITHM BASED ON THE WIGNER - VILLE DISTRIBUTION K.I. SCHULTZ Group 52 TECHNICAL REPORT 855 18 OCTOBER 1989 Approved for public release

  18. A distributed data base management facility for the CAD/CAM environment

    NASA Technical Reports Server (NTRS)

    Balza, R. M.; Beaudet, R. W.; Johnson, H. R.

    1984-01-01

    Current/PAD research in the area of distributed data base management considers facilities for supporting CAD/CAM data management in a heterogeneous network of computers encompassing multiple data base managers supporting a variety of data models. These facilities include coordinated execution of multiple DBMSs to provide for administration of and access to data distributed across them.

  19. A Semantics-Based Information Distribution Framework for Large Web-Based Course Forum System

    ERIC Educational Resources Information Center

    Chim, Hung; Deng, Xiaotie

    2008-01-01

    We propose a novel data distribution framework for developing a large Web-based course forum system. In the distributed architectural design, each forum server is fully equipped with the ability to support some course forums independently. The forum servers collaborating with each other constitute the whole forum system. Therefore, the workload of…

  20. Mathematical Frameworks for Diagnostics, Prognostics and Condition Based Maintenance Problems

    DTIC Science & Technology

    2008-08-15

    REPORT Mathematical Frameworks for Diagnostics, Prognostics and Condition Based Maintenance Problems (W911NF-05-1-0426) 14. ABSTRACT 16. SECURITY ...other documentation. 12. DISTRIBUTION AVAILIBILITY STATEMENT Approved for Public Release; Distribution Unlimited 9. SPONSORING/MONITORING AGENCY NAME...parallel and distributed computing environment were researched. In support of the Condition Based Maintenance (CBM) philosophy, a theoretical framework

  1. A Metrics-Based Approach to Intrusion Detection System Evaluation for Distributed Real-Time Systems

    DTIC Science & Technology

    2002-04-01

    Based Approach to Intrusion Detection System Evaluation for Distributed Real - Time Systems Authors: G. A. Fink, B. L. Chappell, T. G. Turner, and...Distributed, Security. 1 Introduction Processing and cost requirements are driving future naval combat platforms to use distributed, real - time systems of...distributed, real - time systems . As these systems grow more complex, the timing requirements do not diminish; indeed, they may become more constrained

  2. Few-mode fiber based distributed curvature sensor through quasi-single-mode Brillouin frequency shift.

    PubMed

    Wu, Hao; Wang, Ruoxu; Liu, Deming; Fu, Songnian; Zhao, Can; Wei, Huifeng; Tong, Weijun; Shum, Perry Ping; Tang, Ming

    2016-04-01

    We proposed and demonstrated a few-mode fiber (FMF) based optical-fiber sensor for distributed curvature measurement through quasi-single-mode Brillouin frequency shift (BFS). By central-alignment splicing FMF and single-mode fiber (SMF) with a fusion taper, a SMF-components-compatible distributed curvature sensor based on FMF is realized using the conventional Brillouin optical time-domain analysis system. The distributed BFS change induced by bending in FMF has been theoretically and experimentally investigated. The precise BFS response to the curvature along the fiber link has been calibrated. A proof-of-concept experiment is implemented to validate its effectiveness in distributed curvature measurement.

  3. Development of uncertainty-based work injury model using Bayesian structural equation modelling.

    PubMed

    Chatterjee, Snehamoy

    2014-01-01

    This paper proposed a Bayesian method-based structural equation model (SEM) of miners' work injury for an underground coal mine in India. The environmental and behavioural variables for work injury were identified and causal relationships were developed. For Bayesian modelling, prior distributions of SEM parameters are necessary to develop the model. In this paper, two approaches were adopted to obtain prior distribution for factor loading parameters and structural parameters of SEM. In the first approach, the prior distributions were considered as a fixed distribution function with specific parameter values, whereas, in the second approach, prior distributions of the parameters were generated from experts' opinions. The posterior distributions of these parameters were obtained by applying Bayesian rule. The Markov Chain Monte Carlo sampling in the form Gibbs sampling was applied for sampling from the posterior distribution. The results revealed that all coefficients of structural and measurement model parameters are statistically significant in experts' opinion-based priors, whereas, two coefficients are not statistically significant when fixed prior-based distributions are applied. The error statistics reveals that Bayesian structural model provides reasonably good fit of work injury with high coefficient of determination (0.91) and less mean squared error as compared to traditional SEM.

  4. Analytical performance specifications for changes in assay bias (Δbias) for data with logarithmic distributions as assessed by effects on reference change values.

    PubMed

    Petersen, Per H; Lund, Flemming; Fraser, Callum G; Sölétormos, György

    2016-11-01

    Background The distributions of within-subject biological variation are usually described as coefficients of variation, as are analytical performance specifications for bias, imprecision and other characteristics. Estimation of specifications required for reference change values is traditionally done using relationship between the batch-related changes during routine performance, described as Δbias, and the coefficients of variation for analytical imprecision (CV A ): the original theory is based on standard deviations or coefficients of variation calculated as if distributions were Gaussian. Methods The distribution of between-subject biological variation can generally be described as log-Gaussian. Moreover, recent analyses of within-subject biological variation suggest that many measurands have log-Gaussian distributions. In consequence, we generated a model for the estimation of analytical performance specifications for reference change value, with combination of Δbias and CV A based on log-Gaussian distributions of CV I as natural logarithms. The model was tested using plasma prolactin and glucose as examples. Results Analytical performance specifications for reference change value generated using the new model based on log-Gaussian distributions were practically identical with the traditional model based on Gaussian distributions. Conclusion The traditional and simple to apply model used to generate analytical performance specifications for reference change value, based on the use of coefficients of variation and assuming Gaussian distributions for both CV I and CV A , is generally useful.

  5. A gossip based information fusion protocol for distributed frequent itemset mining

    NASA Astrophysics Data System (ADS)

    Sohrabi, Mohammad Karim

    2018-07-01

    The computational complexity, huge memory space requirement, and time-consuming nature of frequent pattern mining process are the most important motivations for distribution and parallelization of this mining process. On the other hand, the emergence of distributed computational and operational environments, which causes the production and maintenance of data on different distributed data sources, makes the parallelization and distribution of the knowledge discovery process inevitable. In this paper, a gossip based distributed itemset mining (GDIM) algorithm is proposed to extract frequent itemsets, which are special types of frequent patterns, in a wireless sensor network environment. In this algorithm, local frequent itemsets of each sensor are extracted using a bit-wise horizontal approach (LHPM) from the nodes which are clustered using a leach-based protocol. Heads of clusters exploit a gossip based protocol in order to communicate each other to find the patterns which their global support is equal to or more than the specified support threshold. Experimental results show that the proposed algorithm outperforms the best existing gossip based algorithm in term of execution time.

  6. Location and Size Planning of Distributed Photovoltaic Generation in Distribution network System Based on K-means Clustering Analysis

    NASA Astrophysics Data System (ADS)

    Lu, Siqi; Wang, Xiaorong; Wu, Junyong

    2018-01-01

    The paper presents a method to generate the planning scenarios, which is based on K-means clustering analysis algorithm driven by data, for the location and size planning of distributed photovoltaic (PV) units in the network. Taken the power losses of the network, the installation and maintenance costs of distributed PV, the profit of distributed PV and the voltage offset as objectives and the locations and sizes of distributed PV as decision variables, Pareto optimal front is obtained through the self-adaptive genetic algorithm (GA) and solutions are ranked by a method called technique for order preference by similarity to an ideal solution (TOPSIS). Finally, select the planning schemes at the top of the ranking list based on different planning emphasis after the analysis in detail. The proposed method is applied to a 10-kV distribution network in Gansu Province, China and the results are discussed.

  7. Statistical analysis of multivariate atmospheric variables. [cloud cover

    NASA Technical Reports Server (NTRS)

    Tubbs, J. D.

    1979-01-01

    Topics covered include: (1) estimation in discrete multivariate distributions; (2) a procedure to predict cloud cover frequencies in the bivariate case; (3) a program to compute conditional bivariate normal parameters; (4) the transformation of nonnormal multivariate to near-normal; (5) test of fit for the extreme value distribution based upon the generalized minimum chi-square; (6) test of fit for continuous distributions based upon the generalized minimum chi-square; (7) effect of correlated observations on confidence sets based upon chi-square statistics; and (8) generation of random variates from specified distributions.

  8. The Application Research of Modern Intelligent Cold Chain Distribution System Based on Internet of Things Technology

    NASA Astrophysics Data System (ADS)

    Fan, Dehui; Gao, Shan

    This paper implemented an intelligent cold chain distribution system based on the technology of Internet of things, and took the protoplasmic beer logistics transport system as example. It realized the remote real-time monitoring material status, recorded the distribution information, dynamically adjusted the distribution tasks and other functions. At the same time, the system combined the Internet of things technology with weighted filtering algorithm, realized the real-time query of condition curve, emergency alarming, distribution data retrieval, intelligent distribution task arrangement, etc. According to the actual test, it can realize the optimization of inventory structure, and improve the efficiency of cold chain distribution.

  9. Fuzzy comprehensive evaluation for grid-connected performance of integrated distributed PV-ES systems

    NASA Astrophysics Data System (ADS)

    Lv, Z. H.; Li, Q.; Huang, R. W.; Liu, H. M.; Liu, D.

    2016-08-01

    Based on the discussion about topology structure of integrated distributed photovoltaic (PV) power generation system and energy storage (ES) in single or mixed type, this paper focuses on analyzing grid-connected performance of integrated distributed photovoltaic and energy storage (PV-ES) systems, and proposes a comprehensive evaluation index system. Then a multi-level fuzzy comprehensive evaluation method based on grey correlation degree is proposed, and the calculations for weight matrix and fuzzy matrix are presented step by step. Finally, a distributed integrated PV-ES power generation system connected to a 380 V low voltage distribution network is taken as the example, and some suggestions are made based on the evaluation results.

  10. Design of Distributed Engine Control Systems with Uncertain Delay.

    PubMed

    Liu, Xiaofeng; Li, Yanxi; Sun, Xu

    Future gas turbine engine control systems will be based on distributed architecture, in which, the sensors and actuators will be connected to the controllers via a communication network. The performance of the distributed engine control (DEC) is dependent on the network performance. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS). Typical turboshaft engine-distributed controllers are designed based on the NCCS framework with a H∞ output feedback under network-induced time delays and uncertain disturbances. The sufficient conditions for robust stability are derived via the Lyapunov stability theory and linear matrix inequality approach. Both numerical and hardware-in-loop simulations illustrate the effectiveness of the presented method.

  11. Design of Distributed Engine Control Systems with Uncertain Delay

    PubMed Central

    Li, Yanxi; Sun, Xu

    2016-01-01

    Future gas turbine engine control systems will be based on distributed architecture, in which, the sensors and actuators will be connected to the controllers via a communication network. The performance of the distributed engine control (DEC) is dependent on the network performance. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS). Typical turboshaft engine-distributed controllers are designed based on the NCCS framework with a H∞ output feedback under network-induced time delays and uncertain disturbances. The sufficient conditions for robust stability are derived via the Lyapunov stability theory and linear matrix inequality approach. Both numerical and hardware-in-loop simulations illustrate the effectiveness of the presented method. PMID:27669005

  12. The Study of Substitution and Elimination Reactions Using Gas Chromatography: An Examination of the Effects of Alkane and Base Structure on Product Distributions

    ERIC Educational Resources Information Center

    Wharry, Donald L.

    2011-01-01

    An experiment that compares product distribution obtained by either substitution or elimination utilizing alkyl bromides and methoxide, ethoxide, or t-butoxide as the base (or nucleophile) is described. The change in product distribution caused by steric effects of the base and substrate are readily apparent. Prior work on this experiment focused…

  13. An Event-Based Approach to Distributed Diagnosis of Continuous Systems

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew; Roychoudhurry, Indranil; Biswas, Gautam; Koutsoukos, Xenofon

    2010-01-01

    Distributed fault diagnosis solutions are becoming necessary due to the complexity of modern engineering systems, and the advent of smart sensors and computing elements. This paper presents a novel event-based approach for distributed diagnosis of abrupt parametric faults in continuous systems, based on a qualitative abstraction of measurement deviations from the nominal behavior. We systematically derive dynamic fault signatures expressed as event-based fault models. We develop a distributed diagnoser design algorithm that uses these models for designing local event-based diagnosers based on global diagnosability analysis. The local diagnosers each generate globally correct diagnosis results locally, without a centralized coordinator, and by communicating a minimal number of measurements between themselves. The proposed approach is applied to a multi-tank system, and results demonstrate a marked improvement in scalability compared to a centralized approach.

  14. An XML-Based Protocol for Distributed Event Services

    NASA Technical Reports Server (NTRS)

    Smith, Warren; Gunter, Dan; Quesnel, Darcy; Biegel, Bryan (Technical Monitor)

    2001-01-01

    A recent trend in distributed computing is the construction of high-performance distributed systems called computational grids. One difficulty we have encountered is that there is no standard format for the representation of performance information and no standard protocol for transmitting this information. This limits the types of performance analysis that can be undertaken in complex distributed systems. To address this problem, we present an XML-based protocol for transmitting performance events in distributed systems and evaluate the performance of this protocol.

  15. Research and Design of the Three-tier Distributed Network Management System Based on COM / COM + and DNA

    NASA Astrophysics Data System (ADS)

    Liang, Likai; Bi, Yushen

    Considered on the distributed network management system's demand of high distributives, extensibility and reusability, a framework model of Three-tier distributed network management system based on COM/COM+ and DNA is proposed, which adopts software component technology and N-tier application software framework design idea. We also give the concrete design plan of each layer of this model. Finally, we discuss the internal running process of each layer in the distributed network management system's framework model.

  16. Native Amazonian children forego egalitarianism in merit-based tasks when they learn to count.

    PubMed

    Jara-Ettinger, Julian; Gibson, Edward; Kidd, Celeste; Piantadosi, Steve

    2016-11-01

    Cooperation often results in a final material resource that must be shared, but deciding how to distribute that resource is not straightforward. A distribution could count as fair if all members receive an equal reward (egalitarian distributions), or if each member's reward is proportional to their merit (merit-based distributions). Here, we propose that the acquisition of numerical concepts influences how we reason about fairness. We explore this possibility in the Tsimane', a farming-foraging group who live in the Bolivian rainforest. The Tsimane' learn to count in the same way children from industrialized countries do, but at a delayed and more variable timeline, allowing us to de-confound number knowledge from age and years in school. We find that Tsimane' children who can count produce merit-based distributions, while children who cannot count produce both merit-based and egalitarian distributions. Our findings establish that the ability to count - a non-universal, language-dependent, cultural invention - can influence social cognition. © 2015 John Wiley & Sons Ltd.

  17. The Extended Erlang-Truncated Exponential distribution: Properties and application to rainfall data.

    PubMed

    Okorie, I E; Akpanta, A C; Ohakwe, J; Chikezie, D C

    2017-06-01

    The Erlang-Truncated Exponential ETE distribution is modified and the new lifetime distribution is called the Extended Erlang-Truncated Exponential EETE distribution. Some statistical and reliability properties of the new distribution are given and the method of maximum likelihood estimate was proposed for estimating the model parameters. The usefulness and flexibility of the EETE distribution was illustrated with an uncensored data set and its fit was compared with that of the ETE and three other three-parameter distributions. Results based on the minimized log-likelihood ([Formula: see text]), Akaike information criterion (AIC), Bayesian information criterion (BIC) and the generalized Cramér-von Mises [Formula: see text] statistics shows that the EETE distribution provides a more reasonable fit than the one based on the other competing distributions.

  18. Competency Based Competitive Events. Integrating DECA into the DE Instructional Program.

    ERIC Educational Resources Information Center

    Cosgrove, Glenna; Moore, Harold W.

    Designed to be integrated into a competency-based distributive education program, these competitive DECA (Distributive Education Clubs of America) events were developed, utilized, and evaluated by distributive education and cooperative education coordinators in Arkansas. These events are organized under the following occupational categories: food…

  19. RTDS-Based Design and Simulation of Distributed P-Q Power Resources in Smart Grid

    NASA Astrophysics Data System (ADS)

    Taylor, Zachariah David

    In this Thesis, we propose to utilize a battery system together with its power electronics interfaces and bidirectional charger as a distributed P-Q resource in power distribution networks. First, we present an optimization-based approach to operate such distributed P-Q resources based on the characteristics of the battery and charger system as well as the features and needs of the power distribution network. Then, we use the RTDS Simulator, which is an industry-standard simulation tool of power systems, to develop two RTDS-based design approaches. The first design is based on an ideal four-quadrant distributed P-Q power resource. The second design is based on a detailed four-quadrant distributed P-Q power resource that is developed using power electronics components. The hardware and power electronics circuitry as well as the control units are explained for the second design. After that, given the two-RTDS designs, we conducted extensive RTDS simulations to assess the performance of the designed distributed P-Q Power Resource in an IEEE 13 bus test system. We observed that the proposed design can noticeably improve the operational performance of the power distribution grid in at least four key aspects: reducing power loss, active power peak load shaving at substation, reactive power peak load shaving at substation, and voltage regulation. We examine these performance measures across three design cases: Case 1: There is no P-Q Power Resource available on the power distribution network. Case 2: The installed P-Q Power Resource only supports active power, i.e., it only utilizes its battery component. Case 3: The installed P-Q Power Resource supports both active and reactive power, i.e., it utilizes both its battery component and its power electronics charger component. In the end, we present insightful interpretations on the simulation results and suggest some future works.

  20. Optimal placement and sizing of wind / solar based DG sources in distribution system

    NASA Astrophysics Data System (ADS)

    Guan, Wanlin; Guo, Niao; Yu, Chunlai; Chen, Xiaoguang; Yu, Haiyang; Liu, Zhipeng; Cui, Jiapeng

    2017-06-01

    Proper placement and sizing of Distributed Generation (DG) in distribution system can obtain maximum potential benefits. This paper proposes quantum particle swarm algorithm (QPSO) based wind turbine generation unit (WTGU) and photovoltaic (PV) array placement and sizing approach for real power loss reduction and voltage stability improvement of distribution system. Performance modeling of wind and solar generation system are described and classified into PQ\\PQ (V)\\PI type models in power flow. Considering the WTGU and PV based DGs in distribution system is geographical restrictive, the optimal area and DG capacity limits of each bus in the setting area need to be set before optimization, the area optimization method is proposed . The method has been tested on IEEE 33-bus radial distribution systems to demonstrate the performance and effectiveness of the proposed method.

  1. A new framework of statistical inferences based on the valid joint sampling distribution of the observed counts in an incomplete contingency table.

    PubMed

    Tian, Guo-Liang; Li, Hui-Qiong

    2017-08-01

    Some existing confidence interval methods and hypothesis testing methods in the analysis of a contingency table with incomplete observations in both margins entirely depend on an underlying assumption that the sampling distribution of the observed counts is a product of independent multinomial/binomial distributions for complete and incomplete counts. However, it can be shown that this independency assumption is incorrect and can result in unreliable conclusions because of the under-estimation of the uncertainty. Therefore, the first objective of this paper is to derive the valid joint sampling distribution of the observed counts in a contingency table with incomplete observations in both margins. The second objective is to provide a new framework for analyzing incomplete contingency tables based on the derived joint sampling distribution of the observed counts by developing a Fisher scoring algorithm to calculate maximum likelihood estimates of parameters of interest, the bootstrap confidence interval methods, and the bootstrap testing hypothesis methods. We compare the differences between the valid sampling distribution and the sampling distribution under the independency assumption. Simulation studies showed that average/expected confidence-interval widths of parameters based on the sampling distribution under the independency assumption are shorter than those based on the new sampling distribution, yielding unrealistic results. A real data set is analyzed to illustrate the application of the new sampling distribution for incomplete contingency tables and the analysis results again confirm the conclusions obtained from the simulation studies.

  2. Study of Charge Transport in Vertically Aligned Nitride Nanowire Based Core Shell P-I-N Junctions

    DTIC Science & Technology

    2016-07-01

    Vertically- Aligned Nitride Nanowire Based Core Shell P-I-N Junctions Distribution Statement A. Approved for public release; distribution is...Study of Charge Transport in Vertically- Aligned Nitride Nanowire Based Core Shell P-I-N Junctions Grant Number: HDTRA1-14-1-0003 Principal...Investigator: Abhishek Motayed University of Maryland DISTRIBUTION A: Public Release Study of Charge Transport in Vertically-Aligned Nitride Nanowire

  3. Distributive Education Competency-Based Curriculum Models by Occupational Clusters. Final Report.

    ERIC Educational Resources Information Center

    Davis, Rodney E.; Husted, Stewart W.

    To meet the needs of distributive education teachers and students, a project was initiated to develop competency-based curriculum models for marketing and distributive education clusters. The models which were developed incorporate competencies, materials and resources, teaching methodologies/learning activities, and evaluative criteria for the…

  4. Content Management Middleware for the Support of Distributed Teaching

    ERIC Educational Resources Information Center

    Tsalapatas, Hariklia; Stav, John B.; Kalantzis, Christos

    2004-01-01

    eCMS is a web-based federated content management system for the support of distributed teaching based on an open, distributed middleware architecture for the publication, discovery, retrieval, and integration of educational material. The infrastructure supports the management of both standalone material and structured courses, as well as the…

  5. Indiana Distributive Education Competency Based Model.

    ERIC Educational Resources Information Center

    Davis, Rod; And Others

    This Indiana distributive education competency-based curriculum model is designed to help teachers and local administrators plan and conduct a comprehensive marketing and distributive education program. It is divided into three levels--one level for each year of a three-year program. The competencies common to a variety of marketing and…

  6. Evaluating simplistic methods to understand current distributions and forecast distribution changes under climate change scenarios: An example with coypu (Myocastor coypus)

    USGS Publications Warehouse

    Jarnevich, Catherine S.; Young, Nicholas E; Sheffels, Trevor R.; Carter, Jacoby; Systma, Mark D.; Talbert, Colin

    2017-01-01

    Invasive species provide a unique opportunity to evaluate factors controlling biogeographic distributions; we can consider introduction success as an experiment testing suitability of environmental conditions. Predicting potential distributions of spreading species is not easy, and forecasting potential distributions with changing climate is even more difficult. Using the globally invasive coypu (Myocastor coypus [Molina, 1782]), we evaluate and compare the utility of a simplistic ecophysiological based model and a correlative model to predict current and future distribution. The ecophysiological model was based on winter temperature relationships with nutria survival. We developed correlative statistical models using the Software for Assisted Habitat Modeling and biologically relevant climate data with a global extent. We applied the ecophysiological based model to several global circulation model (GCM) predictions for mid-century. We used global coypu introduction data to evaluate these models and to explore a hypothesized physiological limitation, finding general agreement with known coypu distribution locally and globally and support for an upper thermal tolerance threshold. Global circulation model based model results showed variability in coypu predicted distribution among GCMs, but had general agreement of increasing suitable area in the USA. Our methods highlighted the dynamic nature of the edges of the coypu distribution due to climate non-equilibrium, and uncertainty associated with forecasting future distributions. Areas deemed suitable habitat, especially those on the edge of the current known range, could be used for early detection of the spread of coypu populations for management purposes. Combining approaches can be beneficial to predicting potential distributions of invasive species now and in the future and in exploring hypotheses of factors controlling distributions.

  7. Delineating Hydrofacies Spatial Distribution by Integrating Ensemble Data Assimilation and Indicator Geostatistics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Xuehang; Chen, Xingyuan; Ye, Ming

    2015-07-01

    This study develops a new framework of facies-based data assimilation for characterizing spatial distribution of hydrofacies and estimating their associated hydraulic properties. This framework couples ensemble data assimilation with transition probability-based geostatistical model via a parameterization based on a level set function. The nature of ensemble data assimilation makes the framework efficient and flexible to be integrated with various types of observation data. The transition probability-based geostatistical model keeps the updated hydrofacies distributions under geological constrains. The framework is illustrated by using a two-dimensional synthetic study that estimates hydrofacies spatial distribution and permeability in each hydrofacies from transient head data.more » Our results show that the proposed framework can characterize hydrofacies distribution and associated permeability with adequate accuracy even with limited direct measurements of hydrofacies. Our study provides a promising starting point for hydrofacies delineation in complex real problems.« less

  8. A relational data-knowledge base system and its potential in developing a distributed data-knowledge system

    NASA Technical Reports Server (NTRS)

    Rahimian, Eric N.; Graves, Sara J.

    1988-01-01

    A new approach used in constructing a rational data knowledge base system is described. The relational database is well suited for distribution due to its property of allowing data fragmentation and fragmentation transparency. An example is formulated of a simple relational data knowledge base which may be generalized for use in developing a relational distributed data knowledge base system. The efficiency and ease of application of such a data knowledge base management system is briefly discussed. Also discussed are the potentials of the developed model for sharing the data knowledge base as well as the possible areas of difficulty in implementing the relational data knowledge base management system.

  9. Reliability Estimation of Aero-engine Based on Mixed Weibull Distribution Model

    NASA Astrophysics Data System (ADS)

    Yuan, Zhongda; Deng, Junxiang; Wang, Dawei

    2018-02-01

    Aero-engine is a complex mechanical electronic system, based on analysis of reliability of mechanical electronic system, Weibull distribution model has an irreplaceable role. Till now, only two-parameter Weibull distribution model and three-parameter Weibull distribution are widely used. Due to diversity of engine failure modes, there is a big error with single Weibull distribution model. By contrast, a variety of engine failure modes can be taken into account with mixed Weibull distribution model, so it is a good statistical analysis model. Except the concept of dynamic weight coefficient, in order to make reliability estimation result more accurately, three-parameter correlation coefficient optimization method is applied to enhance Weibull distribution model, thus precision of mixed distribution reliability model is improved greatly. All of these are advantageous to popularize Weibull distribution model in engineering applications.

  10. Full Waveform Inversion Using Student's t Distribution: a Numerical Study for Elastic Waveform Inversion and Simultaneous-Source Method

    NASA Astrophysics Data System (ADS)

    Jeong, Woodon; Kang, Minji; Kim, Shinwoong; Min, Dong-Joo; Kim, Won-Ki

    2015-06-01

    Seismic full waveform inversion (FWI) has primarily been based on a least-squares optimization problem for data residuals. However, the least-squares objective function can suffer from its weakness and sensitivity to noise. There have been numerous studies to enhance the robustness of FWI by using robust objective functions, such as l 1-norm-based objective functions. However, the l 1-norm can suffer from a singularity problem when the residual wavefield is very close to zero. Recently, Student's t distribution has been applied to acoustic FWI to give reasonable results for noisy data. Student's t distribution has an overdispersed density function compared with the normal distribution, and is thus useful for data with outliers. In this study, we investigate the feasibility of Student's t distribution for elastic FWI by comparing its basic properties with those of the l 2-norm and l 1-norm objective functions and by applying the three methods to noisy data. Our experiments show that the l 2-norm is sensitive to noise, whereas the l 1-norm and Student's t distribution objective functions give relatively stable and reasonable results for noisy data. When noise patterns are complicated, i.e., due to a combination of missing traces, unexpected outliers, and random noise, FWI based on Student's t distribution gives better results than l 1- and l 2-norm FWI. We also examine the application of simultaneous-source methods to acoustic FWI based on Student's t distribution. Computing the expectation of the coefficients of gradient and crosstalk noise terms and plotting the signal-to-noise ratio with iteration, we were able to confirm that crosstalk noise is suppressed as the iteration progresses, even when simultaneous-source FWI is combined with Student's t distribution. From our experiments, we conclude that FWI based on Student's t distribution can retrieve subsurface material properties with less distortion from noise than l 1- and l 2-norm FWI, and the simultaneous-source method can be adopted to improve the computational efficiency of FWI based on Student's t distribution.

  11. Circular distributions based on nonnegative trigonometric sums.

    PubMed

    Fernández-Durán, J J

    2004-06-01

    A new family of distributions for circular random variables is proposed. It is based on nonnegative trigonometric sums and can be used to model data sets which present skewness and/or multimodality. In this family of distributions, the trigonometric moments are easily expressed in terms of the parameters of the distribution. The proposed family is applied to two data sets, one related with the directions taken by ants and the other with the directions taken by turtles, to compare their goodness of fit versus common distributions used in the literature.

  12. Pharmacy-based distribution system for enteral nutrition products.

    PubMed

    Craig, S A; Paulson, M F

    1985-12-01

    A hospital pharmacy department's implementation of enteral nutrition product distribution and its proposal for an enteral nutrition product admixture service are described. Responsibility for the distribution of enteral nutrition formulations was transferred from the central distribution department to the pharmacy after problems with inventory control, billing procedures, and inappropriate administration of enteral nutrition products were recognized by personnel from the central-distribution area and nutrition services. After additional problems were identified using a multi-disciplinary approach, the pharmacy department implemented an enteral nutrition product distribution system and developed an enteral nutrition product formulary. A proposal was developed for a pharmacy-based enteral nutrition admixture service, but implementation of this service was deferred because data from a cost-effectiveness evaluation and random bacteriologic monitoring did not justify adding the service. Pharmacy-based distribution and formulary control of enteral nutrition products alleviated problems with inaccurate patient charges and accumulation of stock on the nursing units. Pharmacists at this hospital hope to develop an enteral nutrition product admixture program that will result in cost savings for the institution.

  13. Simultaneous reconstruction of 3D refractive index, temperature, and intensity distribution of combustion flame by double computed tomography technologies based on spatial phase-shifting method

    NASA Astrophysics Data System (ADS)

    Guo, Zhenyan; Song, Yang; Yuan, Qun; Wulan, Tuya; Chen, Lei

    2017-06-01

    In this paper, a transient multi-parameter three-dimensional (3D) reconstruction method is proposed to diagnose and visualize a combustion flow field. Emission and transmission tomography based on spatial phase-shifted technology are combined to reconstruct, simultaneously, the various physical parameter distributions of a propane flame. Two cameras triggered by the internal trigger mode capture the projection information of the emission and moiré tomography, respectively. A two-step spatial phase-shifting method is applied to extract the phase distribution in the moiré fringes. By using the filtered back-projection algorithm, we reconstruct the 3D refractive-index distribution of the combustion flow field. Finally, the 3D temperature distribution of the flame is obtained from the refractive index distribution using the Gladstone-Dale equation. Meanwhile, the 3D intensity distribution is reconstructed based on the radiation projections from the emission tomography. Therefore, the structure and edge information of the propane flame are well visualized.

  14. Study of distributed learning as a solution to category proliferation in Fuzzy ARTMAP based neural systems.

    PubMed

    Parrado-Hernández, Emilio; Gómez-Sánchez, Eduardo; Dimitriadis, Yannis A

    2003-09-01

    An evaluation of distributed learning as a means to attenuate the category proliferation problem in Fuzzy ARTMAP based neural systems is carried out, from both qualitative and quantitative points of view. The study involves two original winner-take-all (WTA) architectures, Fuzzy ARTMAP and FasArt, and their distributed versions, dARTMAP and dFasArt. A qualitative analysis of the distributed learning properties of dARTMAP is made, focusing on the new elements introduced to endow Fuzzy ARTMAP with distributed learning. In addition, a quantitative study on a selected set of classification problems points out that problems have to present certain features in their output classes in order to noticeably reduce the number of recruited categories and achieve an acceptable classification accuracy. As part of this analysis, distributed learning was successfully adapted to a member of the Fuzzy ARTMAP family, FasArt, and similar procedures can be used to extend distributed learning capabilities to other Fuzzy ARTMAP based systems.

  15. [Study on suitable distribution areas of Grifola umbellate in Sichuan province based on remote sensing and GIS].

    PubMed

    Zhang, You; Wang, Juan; Zhang, Jie; Peng, Wen-Fu; Xu, Xin-Liang; Fang, Qing-Mao

    2016-09-01

    Grifola umbellate is the important medicinal materials in China which has a very high medicinal value. This study analyzedthe suitable distribution areasof G. umbellate and provided scientific basis for determining G. umbellate planting regions and planning production distribution reasonably. The suitable distribution areas of G. umbellate in Sichuan province was researched based on TM, ETM+, and DEM data,the key ecological factors that affect the growth of G. umbellate were extracted, including elevation, slope, aspect, average annual temperature,average annual precipitation,forest information,soil information, following remote sensing and GIS techniques, combining field researchdata. The results showed that the G. umbellate resources in Sichuan province were mainly distributed in Pingwu, Beichuan, Licountry, Yanyuan, Xichang, Dechang, Yanbian, Miyi, Huidong, Panzhihua and so on, the suitability distribution areas is 276.214 4 km² approximately and accounting for more than 0.143 3% of the total area.According to the related document information and the field investigation, showed that the suitability distribution based on RS and GIS were corresponded with the actual distribution areas of G. umbellate. Copyright© by the Chinese Pharmaceutical Association.

  16. Model-Based Diagnosis in a Power Distribution Test-Bed

    NASA Technical Reports Server (NTRS)

    Scarl, E.; McCall, K.

    1998-01-01

    The Rodon model-based diagnosis shell was applied to a breadboard test-bed, modeling an automated power distribution system. The constraint-based modeling paradigm and diagnostic algorithm were found to adequately represent the selected set of test scenarios.

  17. Content Based Image Retrieval based on Wavelet Transform coefficients distribution

    PubMed Central

    Lamard, Mathieu; Cazuguel, Guy; Quellec, Gwénolé; Bekri, Lynda; Roux, Christian; Cochener, Béatrice

    2007-01-01

    In this paper we propose a content based image retrieval method for diagnosis aid in medical fields. We characterize images without extracting significant features by using distribution of coefficients obtained by building signatures from the distribution of wavelet transform. The research is carried out by computing signature distances between the query and database images. Several signatures are proposed; they use a model of wavelet coefficient distribution. To enhance results, a weighted distance between signatures is used and an adapted wavelet base is proposed. Retrieval efficiency is given for different databases including a diabetic retinopathy, a mammography and a face database. Results are promising: the retrieval efficiency is higher than 95% for some cases using an optimization process. PMID:18003013

  18. Unfolding sphere size distributions with a density estimator based on Tikhonov regularization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Weese, J.; Korat, E.; Maier, D.

    1997-12-01

    This report proposes a method for unfolding sphere size distributions given a sample of radii that combines the advantages of a density estimator with those of Tikhonov regularization methods. The following topics are discusses in this report to achieve this method: the relation between the profile and the sphere size distribution; the method for unfolding sphere size distributions; the results based on simulations; and the experimental data comparison.

  19. A Study on the Feasibility of Creating a Web-Accessible Marine Mammal Sound Library Based upon the Collections at the Woods Hole Oceanographic Institution

    DTIC Science & Technology

    2008-09-01

    NPS-OC-08-005 NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA Approved for public release; distribution is...official policy or position of the Department of Defense or the U.S. Government. 12a. DISTRIBUTION / AVAILABILITY STATEMENT Approved for public...release; distribution is unlimited. 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) A universally accessible web-based marine

  20. PRAIS: Distributed, real-time knowledge-based systems made easy

    NASA Technical Reports Server (NTRS)

    Goldstein, David G.

    1990-01-01

    This paper discusses an architecture for real-time, distributed (parallel) knowledge-based systems called the Parallel Real-time Artificial Intelligence System (PRAIS). PRAIS strives for transparently parallelizing production (rule-based) systems, even when under real-time constraints. PRAIS accomplishes these goals by incorporating a dynamic task scheduler, operating system extensions for fact handling, and message-passing among multiple copies of CLIPS executing on a virtual blackboard. This distributed knowledge-based system tool uses the portability of CLIPS and common message-passing protocols to operate over a heterogeneous network of processors.

  1. Time difference of arrival estimation of microseismic signals based on alpha-stable distribution

    NASA Astrophysics Data System (ADS)

    Jia, Rui-Sheng; Gong, Yue; Peng, Yan-Jun; Sun, Hong-Mei; Zhang, Xing-Li; Lu, Xin-Ming

    2018-05-01

    Microseismic signals are generally considered to follow the Gauss distribution. A comparison of the dynamic characteristics of sample variance and the symmetry of microseismic signals with the signals which follow α-stable distribution reveals that the microseismic signals have obvious pulse characteristics and that the probability density curve of the microseismic signal is approximately symmetric. Thus, the hypothesis that microseismic signals follow the symmetric α-stable distribution is proposed. On the premise of this hypothesis, the characteristic exponent α of the microseismic signals is obtained by utilizing the fractional low-order statistics, and then a new method of time difference of arrival (TDOA) estimation of microseismic signals based on fractional low-order covariance (FLOC) is proposed. Upon applying this method to the TDOA estimation of Ricker wavelet simulation signals and real microseismic signals, experimental results show that the FLOC method, which is based on the assumption of the symmetric α-stable distribution, leads to enhanced spatial resolution of the TDOA estimation relative to the generalized cross correlation (GCC) method, which is based on the assumption of the Gaussian distribution.

  2. Analysis of Product Distribution Strategy in Digital Publishing Industry Based on Game-Theory

    NASA Astrophysics Data System (ADS)

    Xu, Li-ping; Chen, Haiyan

    2017-04-01

    The digital publishing output increased significantly year by year. It has been the most vigorous point of economic growth and has been more important to press and publication industry. Its distribution channel has been diversified, which is different from the traditional industry. A deep research has been done in digital publishing industry, for making clear of the constitution of the industry chain and establishing the model of industry chain. The cooperative and competitive relationship between different distribution channels have been analyzed basing on a game-theory. By comparing the distribution quantity and the market size between the static distribution strategy and dynamic distribution strategy, we get the theory evidence about how to choose the distribution strategy to get the optimal benefit.

  3. Photon event distribution sampling: an image formation technique for scanning microscopes that permits tracking of sub-diffraction particles with high spatial and temporal resolutions.

    PubMed

    Larkin, J D; Publicover, N G; Sutko, J L

    2011-01-01

    In photon event distribution sampling, an image formation technique for scanning microscopes, the maximum likelihood position of origin of each detected photon is acquired as a data set rather than binning photons in pixels. Subsequently, an intensity-related probability density function describing the uncertainty associated with the photon position measurement is applied to each position and individual photon intensity distributions are summed to form an image. Compared to pixel-based images, photon event distribution sampling images exhibit increased signal-to-noise and comparable spatial resolution. Photon event distribution sampling is superior to pixel-based image formation in recognizing the presence of structured (non-random) photon distributions at low photon counts and permits use of non-raster scanning patterns. A photon event distribution sampling based method for localizing single particles derived from a multi-variate normal distribution is more precise than statistical (Gaussian) fitting to pixel-based images. Using the multi-variate normal distribution method, non-raster scanning and a typical confocal microscope, localizations with 8 nm precision were achieved at 10 ms sampling rates with acquisition of ~200 photons per frame. Single nanometre precision was obtained with a greater number of photons per frame. In summary, photon event distribution sampling provides an efficient way to form images when low numbers of photons are involved and permits particle tracking with confocal point-scanning microscopes with nanometre precision deep within specimens. © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  4. Leads Detection Using Mixture Statistical Distribution Based CRF Algorithm from Sentinel-1 Dual Polarization SAR Imagery

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Li, Fei; Zhang, Shengkai; Zhu, Tingting

    2017-04-01

    Synthetic Aperture Radar (SAR) is significantly important for polar remote sensing since it can provide continuous observations in all days and all weather. SAR can be used for extracting the surface roughness information characterized by the variance of dielectric properties and different polarization channels, which make it possible to observe different ice types and surface structure for deformation analysis. In November, 2016, Chinese National Antarctic Research Expedition (CHINARE) 33rd cruise has set sails in sea ice zone in Antarctic. Accurate leads spatial distribution in sea ice zone for routine planning of ship navigation is essential. In this study, the semantic relationship between leads and sea ice categories has been described by the Conditional Random Fields (CRF) model, and leads characteristics have been modeled by statistical distributions in SAR imagery. In the proposed algorithm, a mixture statistical distribution based CRF is developed by considering the contexture information and the statistical characteristics of sea ice for improving leads detection in Sentinel-1A dual polarization SAR imagery. The unary potential and pairwise potential in CRF model is constructed by integrating the posteriori probability estimated from statistical distributions. For mixture statistical distribution parameter estimation, Method of Logarithmic Cumulants (MoLC) is exploited for single statistical distribution parameters estimation. The iteration based Expectation Maximal (EM) algorithm is investigated to calculate the parameters in mixture statistical distribution based CRF model. In the posteriori probability inference, graph-cut energy minimization method is adopted in the initial leads detection. The post-processing procedures including aspect ratio constrain and spatial smoothing approaches are utilized to improve the visual result. The proposed method is validated on Sentinel-1A SAR C-band Extra Wide Swath (EW) Ground Range Detected (GRD) imagery with a pixel spacing of 40 meters near Prydz Bay area, East Antarctica. Main work is listed as follows: 1) A mixture statistical distribution based CRF algorithm has been developed for leads detection from Sentinel-1A dual polarization images. 2) The assessment of the proposed mixture statistical distribution based CRF method and single distribution based CRF algorithm has been presented. 3) The preferable parameters sets including statistical distributions, the aspect ratio threshold and spatial smoothing window size have been provided. In the future, the proposed algorithm will be developed for the operational Sentinel series data sets processing due to its less time consuming cost and high accuracy in leads detection.

  5. Improving Distributed Diagnosis Through Structural Model Decomposition

    NASA Technical Reports Server (NTRS)

    Bregon, Anibal; Daigle, Matthew John; Roychoudhury, Indranil; Biswas, Gautam; Koutsoukos, Xenofon; Pulido, Belarmino

    2011-01-01

    Complex engineering systems require efficient fault diagnosis methodologies, but centralized approaches do not scale well, and this motivates the development of distributed solutions. This work presents an event-based approach for distributed diagnosis of abrupt parametric faults in continuous systems, by using the structural model decomposition capabilities provided by Possible Conflicts. We develop a distributed diagnosis algorithm that uses residuals computed by extending Possible Conflicts to build local event-based diagnosers based on global diagnosability analysis. The proposed approach is applied to a multitank system, and results demonstrate an improvement in the design of local diagnosers. Since local diagnosers use only a subset of the residuals, and use subsystem models to compute residuals (instead of the global system model), the local diagnosers are more efficient than previously developed distributed approaches.

  6. An automated model-based aim point distribution system for solar towers

    NASA Astrophysics Data System (ADS)

    Schwarzbözl, Peter; Rong, Amadeus; Macke, Ansgar; Säck, Jan-Peter; Ulmer, Steffen

    2016-05-01

    Distribution of heliostat aim points is a major task during central receiver operation, as the flux distribution produced by the heliostats varies continuously with time. Known methods for aim point distribution are mostly based on simple aim point patterns and focus on control strategies to meet local temperature and flux limits of the receiver. Lowering the peak flux on the receiver to avoid hot spots and maximizing thermal output are obviously competing targets that call for a comprehensive optimization process. This paper presents a model-based method for online aim point optimization that includes the current heliostat field mirror quality derived through an automated deflectometric measurement process.

  7. Distributed intrusion detection system based on grid security model

    NASA Astrophysics Data System (ADS)

    Su, Jie; Liu, Yahui

    2008-03-01

    Grid computing has developed rapidly with the development of network technology and it can solve the problem of large-scale complex computing by sharing large-scale computing resource. In grid environment, we can realize a distributed and load balance intrusion detection system. This paper first discusses the security mechanism in grid computing and the function of PKI/CA in the grid security system, then gives the application of grid computing character in the distributed intrusion detection system (IDS) based on Artificial Immune System. Finally, it gives a distributed intrusion detection system based on grid security system that can reduce the processing delay and assure the detection rates.

  8. Autonomous Control Modes and Optimized Path Guidance for Shipboard Landing in High Sea States

    DTIC Science & Technology

    2016-01-29

    Research in Sea-Based Aviation ONR #BAA12-SN-028 CDRL A001 DISTRIBUTION STATEMENT A: Distribution Approved for public release; distribution...is performed under the Office of Naval Research program on Basic and Applied Research in Sea- Based Aviation (ONR BAA12-SN-0028). This project...addresses the Sea Based Aviation (SBA) initiative in Advanced Handling Qualities for Rotorcraft. Landing a rotorcraft on a moving ship deck and under the

  9. Arcade: A Web-Java Based Framework for Distributed Computing

    NASA Technical Reports Server (NTRS)

    Chen, Zhikai; Maly, Kurt; Mehrotra, Piyush; Zubair, Mohammad; Bushnell, Dennis M. (Technical Monitor)

    2000-01-01

    Distributed heterogeneous environments are being increasingly used to execute a variety of large size simulations and computational problems. We are developing Arcade, a web-based environment to design, execute, monitor, and control distributed applications. These targeted applications consist of independent heterogeneous modules which can be executed on a distributed heterogeneous environment. In this paper we describe the overall design of the system and discuss the prototype implementation of the core functionalities required to support such a framework.

  10. Advances in Enterprise Control. AEC Proceedings, November 15-16, 1999/San Diego, California

    DTIC Science & Technology

    1999-11-16

    structure of tropical termite mounds. 2.3. Mechanisms that each agent deposits one unit of pheromone per unit time and that a proportion 0 < E < 1 of the...Stubberud 137 Section 4: Distributed and Agent-Based Strategies 149 Synthetic Pheromones for Distributed Motion Control by H. Van Dyke Parunak and...Computer Engineering, June, 1994. 147 148 Section 4 Distributed and Agent-Based Strategies 149 150 Synthetic Pheromones for Distributed Motion

  11. LEOPARD: A grid-based dispersion relation solver for arbitrary gyrotropic distributions

    NASA Astrophysics Data System (ADS)

    Astfalk, Patrick; Jenko, Frank

    2017-01-01

    Particle velocity distributions measured in collisionless space plasmas often show strong deviations from idealized model distributions. Despite this observational evidence, linear wave analysis in space plasma environments such as the solar wind or Earth's magnetosphere is still mainly carried out using dispersion relation solvers based on Maxwellians or other parametric models. To enable a more realistic analysis, we present the new grid-based kinetic dispersion relation solver LEOPARD (Linear Electromagnetic Oscillations in Plasmas with Arbitrary Rotationally-symmetric Distributions) which no longer requires prescribed model distributions but allows for arbitrary gyrotropic distribution functions. In this work, we discuss the underlying numerical scheme of the code and we show a few exemplary benchmarks. Furthermore, we demonstrate a first application of LEOPARD to ion distribution data obtained from hybrid simulations. In particular, we show that in the saturation stage of the parallel fire hose instability, the deformation of the initial bi-Maxwellian distribution invalidates the use of standard dispersion relation solvers. A linear solver based on bi-Maxwellians predicts further growth even after saturation, while LEOPARD correctly indicates vanishing growth rates. We also discuss how this complies with former studies on the validity of quasilinear theory for the resonant fire hose. In the end, we briefly comment on the role of LEOPARD in directly analyzing spacecraft data, and we refer to an upcoming paper which demonstrates a first application of that kind.

  12. An object-based storage model for distributed remote sensing images

    NASA Astrophysics Data System (ADS)

    Yu, Zhanwu; Li, Zhongmin; Zheng, Sheng

    2006-10-01

    It is very difficult to design an integrated storage solution for distributed remote sensing images to offer high performance network storage services and secure data sharing across platforms using current network storage models such as direct attached storage, network attached storage and storage area network. Object-based storage, as new generation network storage technology emerged recently, separates the data path, the control path and the management path, which solves the bottleneck problem of metadata existed in traditional storage models, and has the characteristics of parallel data access, data sharing across platforms, intelligence of storage devices and security of data access. We use the object-based storage in the storage management of remote sensing images to construct an object-based storage model for distributed remote sensing images. In the storage model, remote sensing images are organized as remote sensing objects stored in the object-based storage devices. According to the storage model, we present the architecture of a distributed remote sensing images application system based on object-based storage, and give some test results about the write performance comparison of traditional network storage model and object-based storage model.

  13. Systems of frequency distributions for water and environmental engineering

    NASA Astrophysics Data System (ADS)

    Singh, Vijay P.

    2018-09-01

    A wide spectrum of frequency distributions are used in hydrologic, hydraulic, environmental and water resources engineering. These distributions may have different origins, are based on different hypotheses, and belong to different generating systems. Review of literature suggests that different systems of frequency distributions employed in science and engineering in general and environmental and water engineering in particular have been derived using different approaches which include (1) differential equations, (2) distribution elasticity, (3) genetic theory, (4) generating functions, (5) transformations, (6) Bessel function, (7) expansions, and (8) entropy maximization. This paper revisits these systems of distributions and discusses the hypotheses that are used for deriving these systems. It also proposes, based on empirical evidence, another general system of distributions and derives a number of distributions from this general system that are used in environmental and water engineering.

  14. Comprehensive evaluation index system of total supply capability in distribution network

    NASA Astrophysics Data System (ADS)

    Zhang, Linyao; Wu, Guilian; Yang, Jingyuan; Jia, Shuangrui; Zhang, Wei; Sun, Weiqing

    2018-01-01

    Aiming at the lack of a comprehensive evaluation of the distribution network, based on the existing distribution network evaluation index system, combined with the basic principles of constructing the evaluation index, put forward a new evaluation index system of distribution network capacity. This paper is mainly based on the total supply capability of the distribution network, combining single index and various factors, into a multi-evaluation index of the distribution network, thus forming a reasonable index system, and various indicators of rational quantification make the evaluation results more intuitive. In order to have a comprehensive judgment of distribution network, this paper uses weights to analyse the importance of each index, verify the rationality of the index system through the example, it is proved that the rationality of the index system, so as to guide the direction of distribution network planning.

  15. Organization of the secure distributed computing based on multi-agent system

    NASA Astrophysics Data System (ADS)

    Khovanskov, Sergey; Rumyantsev, Konstantin; Khovanskova, Vera

    2018-04-01

    Nowadays developing methods for distributed computing is received much attention. One of the methods of distributed computing is using of multi-agent systems. The organization of distributed computing based on the conventional network computers can experience security threats performed by computational processes. Authors have developed the unified agent algorithm of control system of computing network nodes operation. Network PCs is used as computing nodes. The proposed multi-agent control system for the implementation of distributed computing allows in a short time to organize using of the processing power of computers any existing network to solve large-task by creating a distributed computing. Agents based on a computer network can: configure a distributed computing system; to distribute the computational load among computers operated agents; perform optimization distributed computing system according to the computing power of computers on the network. The number of computers connected to the network can be increased by connecting computers to the new computer system, which leads to an increase in overall processing power. Adding multi-agent system in the central agent increases the security of distributed computing. This organization of the distributed computing system reduces the problem solving time and increase fault tolerance (vitality) of computing processes in a changing computing environment (dynamic change of the number of computers on the network). Developed a multi-agent system detects cases of falsification of the results of a distributed system, which may lead to wrong decisions. In addition, the system checks and corrects wrong results.

  16. Data center thermal management

    DOEpatents

    Hamann, Hendrik F.; Li, Hongfei

    2016-02-09

    Historical high-spatial-resolution temperature data and dynamic temperature sensor measurement data may be used to predict temperature. A first formulation may be derived based on the historical high-spatial-resolution temperature data for determining a temperature at any point in 3-dimensional space. The dynamic temperature sensor measurement data may be calibrated based on the historical high-spatial-resolution temperature data at a corresponding historical time. Sensor temperature data at a plurality of sensor locations may be predicted for a future time based on the calibrated dynamic temperature sensor measurement data. A three-dimensional temperature spatial distribution associated with the future time may be generated based on the forecasted sensor temperature data and the first formulation. The three-dimensional temperature spatial distribution associated with the future time may be projected to a two-dimensional temperature distribution, and temperature in the future time for a selected space location may be forecasted dynamically based on said two-dimensional temperature distribution.

  17. Bluetooth-based distributed measurement system

    NASA Astrophysics Data System (ADS)

    Tang, Baoping; Chen, Zhuo; Wei, Yuguo; Qin, Xiaofeng

    2007-07-01

    A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

  18. A development framework for artificial intelligence based distributed operations support systems

    NASA Technical Reports Server (NTRS)

    Adler, Richard M.; Cottman, Bruce H.

    1990-01-01

    Advanced automation is required to reduce costly human operations support requirements for complex space-based and ground control systems. Existing knowledge based technologies have been used successfully to automate individual operations tasks. Considerably less progress has been made in integrating and coordinating multiple operations applications for unified intelligent support systems. To fill this gap, SOCIAL, a tool set for developing Distributed Artificial Intelligence (DAI) systems is being constructed. SOCIAL consists of three primary language based components defining: models of interprocess communication across heterogeneous platforms; models for interprocess coordination, concurrency control, and fault management; and for accessing heterogeneous information resources. DAI applications subsystems, either new or existing, will access these distributed services non-intrusively, via high-level message-based protocols. SOCIAL will reduce the complexity of distributed communications, control, and integration, enabling developers to concentrate on the design and functionality of the target DAI system itself.

  19. Density-based empirical likelihood procedures for testing symmetry of data distributions and K-sample comparisons.

    PubMed

    Vexler, Albert; Tanajian, Hovig; Hutson, Alan D

    In practice, parametric likelihood-ratio techniques are powerful statistical tools. In this article, we propose and examine novel and simple distribution-free test statistics that efficiently approximate parametric likelihood ratios to analyze and compare distributions of K groups of observations. Using the density-based empirical likelihood methodology, we develop a Stata package that applies to a test for symmetry of data distributions and compares K -sample distributions. Recognizing that recent statistical software packages do not sufficiently address K -sample nonparametric comparisons of data distributions, we propose a new Stata command, vxdbel, to execute exact density-based empirical likelihood-ratio tests using K samples. To calculate p -values of the proposed tests, we use the following methods: 1) a classical technique based on Monte Carlo p -value evaluations; 2) an interpolation technique based on tabulated critical values; and 3) a new hybrid technique that combines methods 1 and 2. The third, cutting-edge method is shown to be very efficient in the context of exact-test p -value computations. This Bayesian-type method considers tabulated critical values as prior information and Monte Carlo generations of test statistic values as data used to depict the likelihood function. In this case, a nonparametric Bayesian method is proposed to compute critical values of exact tests.

  20. The Case For Prediction-based Best-effort Real-time Systems.

    DTIC Science & Technology

    1999-01-01

    Real - time Systems Peter A. Dinda Loukas Kallivokas January...DISTRIBUTION STATEMENT A Approved for Public Release Distribution Unlimited DTIG QUALBR DISSECTED X The Case For Prediction-based Best-effort Real - time Systems Peter...Mellon University Pittsburgh, PA 15213 A version of this paper appeared in the Seventh Workshop on Parallel and Distributed Real - Time Systems

  1. Item Response Theory with Estimation of the Latent Population Distribution Using Spline-Based Densities

    ERIC Educational Resources Information Center

    Woods, Carol M.; Thissen, David

    2006-01-01

    The purpose of this paper is to introduce a new method for fitting item response theory models with the latent population distribution estimated from the data using splines. A spline-based density estimation system provides a flexible alternative to existing procedures that use a normal distribution, or a different functional form, for the…

  2. Local Anesthetic Microencapsulation.

    DTIC Science & Technology

    1983-11-04

    tollowing I.M. injection of microencapsulated lidocaine and etidocaine than following solution injections. Local toxicity of these microcapsule injections...Distribution 41 Table 12 Processing Summary of Lidocaine (Base) 43 Microencapsulation Table 13 Lidocaine (Base) Microcapsule Size 44 Distribution...Table 14 Processing Summary of Et’idocaine-HCl 45 Microencapsulation Table 15 Etidocaine-HCl Microcapsule Size 47 Distribution Table 16 Process Summary

  3. Distance Learning: A Way of Life-Long Learning

    DTIC Science & Technology

    2005-09-01

    promise of future benefits. 15. SUBJECT TERMS training, educational technology , distributed learning , distance learning , collaboration, online instruction...knowledge." - Aristotle Introduction Modern learning technology assumes various names: distance learning , distributed training, computer-based...training, web-based learning , or advanced distributed learning . No matter the name, the basic concept is using computer technology for instruction with no

  4. Distributed Prognostic Health Management with Gaussian Process Regression

    NASA Technical Reports Server (NTRS)

    Saha, Sankalita; Saha, Bhaskar; Saxena, Abhinav; Goebel, Kai Frank

    2010-01-01

    Distributed prognostics architecture design is an enabling step for efficient implementation of health management systems. A major challenge encountered in such design is formulation of optimal distributed prognostics algorithms. In this paper. we present a distributed GPR based prognostics algorithm whose target platform is a wireless sensor network. In addition to challenges encountered in a distributed implementation, a wireless network poses constraints on communication patterns, thereby making the problem more challenging. The prognostics application that was used to demonstrate our new algorithms is battery prognostics. In order to present trade-offs within different prognostic approaches, we present comparison with the distributed implementation of a particle filter based prognostics for the same battery data.

  5. Classification of Complete Proteomes of Different Organisms and Protein Sets Based on Their Protein Distributions in Terms of Some Key Attributes of Proteins

    PubMed Central

    Ma, Yue; Tuskan, Gerald A.

    2018-01-01

    The existence of complete genome sequences makes it important to develop different approaches for classification of large-scale data sets and to make extraction of biological insights easier. Here, we propose an approach for classification of complete proteomes/protein sets based on protein distributions on some basic attributes. We demonstrate the usefulness of this approach by determining protein distributions in terms of two attributes: protein lengths and protein intrinsic disorder contents (ID). The protein distributions based on L and ID are surveyed for representative proteome organisms and protein sets from the three domains of life. The two-dimensional maps (designated as fingerprints here) from the protein distribution densities in the LD space defined by ln(L) and ID are then constructed. The fingerprints for different organisms and protein sets are found to be distinct with each other, and they can therefore be used for comparative studies. As a test case, phylogenetic trees have been constructed based on the protein distribution densities in the fingerprints of proteomes of organisms without performing any protein sequence comparison and alignments. The phylogenetic trees generated are biologically meaningful, demonstrating that the protein distributions in the LD space may serve as unique phylogenetic signals of the organisms at the proteome level. PMID:29686995

  6. Resource Guide to Competency-Based Vocational Education: Distributive Education.

    ERIC Educational Resources Information Center

    Foster, Phillip R., Comp.

    This resource guide for classroom teachers contains annotations of resources representing recent instructional development in competency-based education for distributive education. It is also intended to assist curriculum specialists, administrators, and supervisors in development of performance-based instructional programs. The guide is divided…

  7. Motion Trajectories for Wide-area Surveying with a Rover-based Distributed Spectrometer

    NASA Technical Reports Server (NTRS)

    Tunstel, Edward; Anderson, Gary; Wilson, Edmond

    2006-01-01

    A mobile ground survey application that employs remote sensing as a primary means of area coverage is highlighted. It is distinguished from mobile robotic area coverage problems that employ contact or proximity-based sensing. The focus is on a specific concept for performing mobile surveys in search of biogenic gases on planetary surfaces using a distributed spectrometer -- a rover-based instrument designed for wide measurement coverage of promising search areas. Navigation algorithms for executing circular and spiral survey trajectories are presented for widearea distributed spectroscopy and evaluated based on area covered and distance traveled.

  8. Optical Access Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Ansari, Nirwan

    2005-02-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks.

  9. On the Feasibility of Prefetching and Caching for Online TV Services: A Measurement Study on Hulu

    NASA Astrophysics Data System (ADS)

    Krishnappa, Dilip Kumar; Khemmarat, Samamon; Gao, Lixin; Zink, Michael

    Lately researchers are looking at ways to reduce the delay on video playback through mechanisms like prefetching and caching for Video-on-Demand (VoD) services. The usage of prefetching and caching also has the potential to reduce the amount of network bandwidth usage, as most popular requests are served from a local cache rather than the server containing the original content. In this paper, we investigate the advantages of having such a prefetching and caching scheme for a free hosting service of professionally created video (movies and TV shows) named "hulu". We look into the advantages of using a prefetching scheme where the most popular videos of the week, as provided by the hulu website, are prefetched and compare this approach with a conventional LRU caching scheme with limited storage space and a combined scheme of prefetching and caching. Results from our measurement and analysis shows that employing a basic caching scheme at the proxy yields a hit ratio of up to 77.69%, but requires storage of about 236GB. Further analysis shows that a prefetching scheme where the top-100 popular videos of the week are downloaded to the proxy yields a hit ratio of 44% with a storage requirement of 10GB. A LRU caching scheme with a storage limitation of 20GB can achieve a hit ratio of 55% but downloads 4713 videos to achieve such high hit ratio compared to 100 videos in prefetching scheme, whereas a scheme with both prefetching and caching with the same storage yields a hit ratio of 59% with download requirement of 4439 videos. We find that employing a scheme of prefetching along with caching with trade-off on the storage will yield a better hit ratio and bandwidth saving than individual caching or prefetching schemes.

  10. Terrestrial Water Storage and Vegetation Resilience to Drought

    NASA Astrophysics Data System (ADS)

    Meyer, V.; Reager, J. T., II; Konings, A. G.

    2017-12-01

    The expected increased occurrences of hydrologic extreme events such as droughts in the coming decades motivates studies to better understand and predict the response of vegetation to such extreme conditions. Previous studies have addressed vegetation resilience to drought, defined as its ability to recover from a perturbation (Hirota et al., 2011; Vicente-Serrano et al., 2012), but appear to only focus on precipitation and a couple of vegetation indices, hence lacking a key element: terrestrial water storage (TWS). In this study, we combine and compare multiple remotely-sensed hydro-ecological datasets providing information on climatic and hydrological conditions (Tropical Rainfall Measuring Mission (TRMM), Gravity Recovery and Climate Experiment (GRACE)) and indices characterizing the state of the vegetation (vegetation water content using Vegetation Optical Depth (VOD) from SMAP (Soil Moisture Active and Passive), Gross Primary Production (GPP) from FluxCom and Specific Fluorescence Intensity (SFI, from GOSat)) to assess the ability of vegetation to face and recover from droughts across the globe. Our results suggest that GRACE hydrological data bridge the knowledge gap between precipitation deficit and vegetation response. All products are aggregated at a 0.5º spatial resolution and a monthly temporal resolution to match the GRACE Mascon product. Despite these coarse spatiotemporal resolutions, we find that the relationship between existing remotely-sensed eco-hydrologic data varies spatially, both in terms of strength of relationship and time lag, showing the response time of vegetation characteristics to hydrological changes and highlighting the role of water storage. A special attention is given to the Amazon river basin, where two well documented droughts occurred in 2005 and 2010, and where a more recent drought occurred in 2015/2016. References : Hirota, Marina, et al. "Global resilience of tropical forest and savanna to critical transitions." Science 334.6053 (2011): 232-235. Vicente-Serrano, Sergio M., et al. "Response of vegetation to drought time-scales across global land biomes." Proceedings of the National Academy of Sciences 110.1 (2013): 52-57.

  11. [Alteration of Microparticle Levels in Early Complications During Hematopoietic Stem Cell Transplantation].

    PubMed

    Zhou, Li-Li; Han, Yue; Zhu, Qian; Zhao, Shi-Xiang; Wang, Qian; Zhu, Ming-Qing; Dai, Lan; Shen, Wen-Hong; Wu, De-Pei

    2015-12-01

    To investigate the alteration of microparticles (MP) in the recipients following hematopoietic stem cell transplantation (HSCT) and its significance, and to search the early diagnostic indicators of thrombotic complications after transplantation. According to the occurrence of transplantation-associated complications, 94 allo-HSCT patients were divided into 4 groups: thrombotic group (VOD n = 7, TMA n = 2), acute graft-versus-host disease (aGVHD) group (n = 27), infection group (n = 41) and non-complication group (n = 17). Alterations of serum concentration of tissue factor positive microparticles (TF(+) MP) and endothelial microparticles (EMP) were analyzed by flow cytometry during the process of conditioning treatment and the early stage after transplantation. The relation of these 2 kinds of MP with complications was analysed. (1) The levels of TF(+) MP and EMP of patients undogoing allo-HSCT before conditioning treatment were obviously higher than those in normal controls, and showed some elevation during different times, but there was no significant statistical difference. Although the levels of TF(+) MP and EMP at the end of conditioning treatment were some higher than those before conditioning treatment, but there was no statistical difference between them. (2)The levels of TF(+) MP and EMP in thrombotic group were obviously higher than those in aGVHD group and infection group (P < 0.05). (3)The levels of TF(+) MP and EMP in thrombotic group at different times were significant differences from those in other groups (P < 0.05), and the levels of TF(+) MP and EMP were no significant difference from those in non-complication group. The increase of the TF(+) MP and EMP levels may be associated with occurrence of thrombosis after transplantation, indicating occurrence of the thrombotic complications, like hepatic vein occulusive disease (HVOD). The dynamically monitoring levels of TF(+) MP and EMP contributes to early discovery of thrombotic complications.

  12. Exploring super-Gaussianity toward robust information-theoretical time delay estimation.

    PubMed

    Petsatodis, Theodoros; Talantzis, Fotios; Boukis, Christos; Tan, Zheng-Hua; Prasad, Ramjee

    2013-03-01

    Time delay estimation (TDE) is a fundamental component of speaker localization and tracking algorithms. Most of the existing systems are based on the generalized cross-correlation method assuming gaussianity of the source. It has been shown that the distribution of speech, captured with far-field microphones, is highly varying, depending on the noise and reverberation conditions. Thus the performance of TDE is expected to fluctuate depending on the underlying assumption for the speech distribution, being also subject to multi-path reflections and competitive background noise. This paper investigates the effect upon TDE when modeling the source signal with different speech-based distributions. An information theoretical TDE method indirectly encapsulating higher order statistics (HOS) formed the basis of this work. The underlying assumption of Gaussian distributed source has been replaced by that of generalized Gaussian distribution that allows evaluating the problem under a larger set of speech-shaped distributions, ranging from Gaussian to Laplacian and Gamma. Closed forms of the univariate and multivariate entropy expressions of the generalized Gaussian distribution are derived to evaluate the TDE. The results indicate that TDE based on the specific criterion is independent of the underlying assumption for the distribution of the source, for the same covariance matrix.

  13. Automated Planning and Scheduling for Planetary Rover Distributed Operations

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.; Rabideau, Gregg; Tso, Kam S.; Chien, Steve

    1999-01-01

    Automated planning and Scheduling, including automated path planning, has been integrated with an Internet-based distributed operations system for planetary rover operations. The resulting prototype system enables faster generation of valid rover command sequences by a distributed planetary rover operations team. The Web Interface for Telescience (WITS) provides Internet-based distributed collaboration, the Automated Scheduling and Planning Environment (ASPEN) provides automated planning and scheduling, and an automated path planner provided path planning. The system was demonstrated on the Rocky 7 research rover at JPL.

  14. An estimation of distribution method for infrared target detection based on Copulas

    NASA Astrophysics Data System (ADS)

    Wang, Shuo; Zhang, Yiqun

    2015-10-01

    Track-before-detect (TBD) based target detection involves a hypothesis test of merit functions which measure each track as a possible target track. Its accuracy depends on the precision of the distribution of merit functions, which determines the threshold for a test. Generally, merit functions are regarded Gaussian, and on this basis the distribution is estimated, which is true for most methods such as the multiple hypothesis tracking (MHT). However, merit functions for some other methods such as the dynamic programming algorithm (DPA) are non-Guassian and cross-correlated. Since existing methods cannot reasonably measure the correlation, the exact distribution can hardly be estimated. If merit functions are assumed Guassian and independent, the error between an actual distribution and its approximation may occasionally over 30 percent, and is divergent by propagation. Hence, in this paper, we propose a novel estimation of distribution method based on Copulas, by which the distribution can be estimated precisely, where the error is less than 1 percent without propagation. Moreover, the estimation merely depends on the form of merit functions and the structure of a tracking algorithm, and is invariant to measurements. Thus, the distribution can be estimated in advance, greatly reducing the demand for real-time calculation of distribution functions.

  15. On the appropriateness of applying chi-square distribution based confidence intervals to spectral estimates of helicopter flyover data

    NASA Technical Reports Server (NTRS)

    Rutledge, Charles K.

    1988-01-01

    The validity of applying chi-square based confidence intervals to far-field acoustic flyover spectral estimates was investigated. Simulated data, using a Kendall series and experimental acoustic data from the NASA/McDonnell Douglas 500E acoustics test, were analyzed. Statistical significance tests to determine the equality of distributions of the simulated and experimental data relative to theoretical chi-square distributions were performed. Bias and uncertainty errors associated with the spectral estimates were easily identified from the data sets. A model relating the uncertainty and bias errors to the estimates resulted, which aided in determining the appropriateness of the chi-square distribution based confidence intervals. Such confidence intervals were appropriate for nontonally associated frequencies of the experimental data but were inappropriate for tonally associated estimate distributions. The appropriateness at the tonally associated frequencies was indicated by the presence of bias error and noncomformity of the distributions to the theoretical chi-square distribution. A technique for determining appropriate confidence intervals at the tonally associated frequencies was suggested.

  16. On Prolonging Network Lifetime through Load-Similar Node Deployment in Wireless Sensor Networks

    PubMed Central

    Li, Qiao-Qin; Gong, Haigang; Liu, Ming; Yang, Mei; Zheng, Jun

    2011-01-01

    This paper is focused on the study of the energy hole problem in the Progressive Multi-hop Rotational Clustered (PMRC)-structure, a highly scalable wireless sensor network (WSN) architecture. Based on an analysis on the traffic load distribution in PMRC-based WSNs, we propose a novel load-similar node distribution strategy combined with the Minimum Overlapping Layers (MOL) scheme to address the energy hole problem in PMRC-based WSNs. In this strategy, sensor nodes are deployed in the network area according to the load distribution. That is, more nodes shall be deployed in the range where the average load is higher, and then the loads among different areas in the sensor network tend to be balanced. Simulation results demonstrate that the load-similar node distribution strategy prolongs network lifetime and reduces the average packet latency in comparison with existing nonuniform node distribution and uniform node distribution strategies. Note that, besides the PMRC structure, the analysis model and the proposed load-similar node distribution strategy are also applicable to other multi-hop WSN structures. PMID:22163809

  17. Metocean design parameter estimation for fixed platform based on copula functions

    NASA Astrophysics Data System (ADS)

    Zhai, Jinjin; Yin, Qilin; Dong, Sheng

    2017-08-01

    Considering the dependent relationship among wave height, wind speed, and current velocity, we construct novel trivariate joint probability distributions via Archimedean copula functions. Total 30-year data of wave height, wind speed, and current velocity in the Bohai Sea are hindcast and sampled for case study. Four kinds of distributions, namely, Gumbel distribution, lognormal distribution, Weibull distribution, and Pearson Type III distribution, are candidate models for marginal distributions of wave height, wind speed, and current velocity. The Pearson Type III distribution is selected as the optimal model. Bivariate and trivariate probability distributions of these environmental conditions are established based on four bivariate and trivariate Archimedean copulas, namely, Clayton, Frank, Gumbel-Hougaard, and Ali-Mikhail-Haq copulas. These joint probability models can maximize marginal information and the dependence among the three variables. The design return values of these three variables can be obtained by three methods: univariate probability, conditional probability, and joint probability. The joint return periods of different load combinations are estimated by the proposed models. Platform responses (including base shear, overturning moment, and deck displacement) are further calculated. For the same return period, the design values of wave height, wind speed, and current velocity obtained by the conditional and joint probability models are much smaller than those by univariate probability. Considering the dependence among variables, the multivariate probability distributions provide close design parameters to actual sea state for ocean platform design.

  18. Resilient Core Networks for Energy Distribution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kuntze, Nicolai; Rudolph, Carsten; Leivesley, Sally

    2014-07-28

    Abstract—Substations and their control are crucial for the availability of electricity in today’s energy distribution. Ad- vanced energy grids with Distributed Energy Resources require higher complexity in substations, distributed functionality and communication between devices inside substations and between substations. Also, substations include more and more intelligent devices and ICT based systems. All these devices are connected to other systems by different types of communication links or are situated in uncontrolled environments. Therefore, the risk of ICT based attacks on energy grids is growing. Consequently, security measures to counter these risks need to be an intrinsic part of energy grids. Thismore » paper introduces the concept of a Resilient Core Network to interconnected substations. This core network provides essen- tial security features, enables fast detection of attacks and allows for a distributed and autonomous mitigation of ICT based risks.« less

  19. Finite Element Simulation and Experimental Verification of Internal Stress of Quenched AISI 4140 Cylinders

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Qin, Shengwei; Hao, Qingguo; Chen, Nailu; Zuo, Xunwei; Rong, Yonghua

    2017-03-01

    The study of internal stress in quenched AISI 4140 medium carbon steel is of importance in engineering. In this work, the finite element simulation (FES) was employed to predict the distribution of internal stress in quenched AISI 4140 cylinders with two sizes of diameter based on exponent-modified (Ex-Modified) normalized function. The results indicate that the FES based on Ex-Modified normalized function proposed is better consistent with X-ray diffraction measurements of the stress distribution than FES based on normalized function proposed by Abrassart, Desalos and Leblond, respectively, which is attributed that Ex-Modified normalized function better describes transformation plasticity. Effect of temperature distribution on the phase formation, the origin of residual stress distribution and effect of transformation plasticity function on the residual stress distribution were further discussed.

  20. Microscopic understanding of heavy-tailed return distributions in an agent-based model

    NASA Astrophysics Data System (ADS)

    Schmitt, Thilo A.; Schäfer, Rudi; Münnix, Michael C.; Guhr, Thomas

    2012-11-01

    The distribution of returns in financial time series exhibits heavy tails. It has been found that gaps between the orders in the order book lead to large price shifts and thereby to these heavy tails. We set up an agent-based model to study this issue and, in particular, how the gaps in the order book emerge. The trading mechanism in our model is based on a double-auction order book. In situations where the order book is densely occupied with limit orders we do not observe fat-tailed distributions. As soon as less liquidity is available, a gap structure forms which leads to return distributions with heavy tails. We show that return distributions with heavy tails are an order-book effect if the available liquidity is constrained. This is largely independent of specific trading strategies.

  1. A Distributed Data Base Version of INGRES.

    ERIC Educational Resources Information Center

    Stonebraker, Michael; Neuhold, Eric

    Extensions are required to the currently operational INGRES data base system for it to manage a data base distributed over multiple machines in a computer network running the UNIX operating system. Three possible user views include: (1) each relation in a unique machine, (2) a user interaction with the data base which can only span relations at a…

  2. Ice Water Classification Using Statistical Distribution Based Conditional Random Fields in RADARSAT-2 Dual Polarization Imagery

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Li, F.; Zhang, S.; Hao, W.; Zhu, T.; Yuan, L.; Xiao, F.

    2017-09-01

    In this paper, Statistical Distribution based Conditional Random Fields (STA-CRF) algorithm is exploited for improving marginal ice-water classification. Pixel level ice concentration is presented as the comparison of methods based on CRF. Furthermore, in order to explore the effective statistical distribution model to be integrated into STA-CRF, five statistical distribution models are investigated. The STA-CRF methods are tested on 2 scenes around Prydz Bay and Adélie Depression, where contain a variety of ice types during melt season. Experimental results indicate that the proposed method can resolve sea ice edge well in Marginal Ice Zone (MIZ) and show a robust distinction of ice and water.

  3. Distributed semantic networks and CLIPS

    NASA Technical Reports Server (NTRS)

    Snyder, James; Rodriguez, Tony

    1991-01-01

    Semantic networks of frames are commonly used as a method of reasoning in many problems. In most of these applications the semantic network exists as a single entity in a single process environment. Advances in workstation hardware provide support for more sophisticated applications involving multiple processes, interacting in a distributed environment. In these applications the semantic network may well be distributed over several concurrently executing tasks. This paper describes the design and implementation of a frame based, distributed semantic network in which frames are accessed both through C Language Integrated Production System (CLIPS) expert systems and procedural C++ language programs. The application area is a knowledge based, cooperative decision making model utilizing both rule based and procedural experts.

  4. Address tracing for parallel machines

    NASA Technical Reports Server (NTRS)

    Stunkel, Craig B.; Janssens, Bob; Fuchs, W. Kent

    1991-01-01

    Recently implemented parallel system address-tracing methods based on several metrics are surveyed. The issues specific to collection of traces for both shared and distributed memory parallel computers are highlighted. Five general categories of address-trace collection methods are examined: hardware-captured, interrupt-based, simulation-based, altered microcode-based, and instrumented program-based traces. The problems unique to shared memory and distributed memory multiprocessors are examined separately.

  5. Network Capacity Assessment of CHP-based Distributed Generation on Urban Energy Distribution Networks

    NASA Astrophysics Data System (ADS)

    Zhang, Xianjun

    The combined heat and power (CHP)-based distributed generation (DG) or dis-tributed energy resources (DERs) are mature options available in the present energy market, considered to be an effective solution to promote energy efficiency. In the urban environment, the electricity, water and natural gas distribution networks are becoming increasingly interconnected with the growing penetration of the CHP-based DG. Subsequently, this emerging interdependence leads to new topics meriting serious consideration: how much of the CHP-based DG can be accommodated and where to locate these DERs, and given preexisting constraints, how to quantify the mutual impacts on operation performances between these urban energy distribution networks and the CHP-based DG. The early research work was conducted to investigate the feasibility and design methods for one residential microgrid system based on existing electricity, water and gas infrastructures of a residential community, mainly focusing on the economic planning. However, this proposed design method cannot determine the optimal DG sizing and siting for a larger test bed with the given information of energy infrastructures. In this context, a more systematic as well as generalized approach should be developed to solve these problems. In the later study, the model architecture that integrates urban electricity, water and gas distribution networks, and the CHP-based DG system was developed. The proposed approach addressed the challenge of identifying the optimal sizing and siting of the CHP-based DG on these urban energy networks and the mutual impacts on operation performances were also quantified. For this study, the overall objective is to maximize the electrical output and recovered thermal output of the CHP-based DG units. The electricity, gas, and water system models were developed individually and coupled by the developed CHP-based DG system model. The resultant integrated system model is used to constrain the DG's electrical output and recovered thermal output, which are affected by multiple factors and thus analyzed in different case studies. The results indicate that the designed typical gas system is capable of supplying sufficient natural gas for the DG normal operation, while the present water system cannot support the complete recovery of the exhaust heat from the DG units.

  6. Design and characterization of planar capacitive imaging probe based on the measurement sensitivity distribution

    NASA Astrophysics Data System (ADS)

    Yin, X.; Chen, G.; Li, W.; Huthchins, D. A.

    2013-01-01

    Previous work indicated that the capacitive imaging (CI) technique is a useful NDE tool which can be used on a wide range of materials, including metals, glass/carbon fibre composite materials and concrete. The imaging performance of the CI technique for a given application is determined by design parameters and characteristics of the CI probe. In this paper, a rapid method for calculating the whole probe sensitivity distribution based on the finite element model (FEM) is presented to provide a direct view of the imaging capabilities of the planar CI probe. Sensitivity distributions of CI probes with different geometries were obtained. Influencing factors on sensitivity distribution were studied. Comparisons between CI probes with point-to-point triangular electrode pair and back-to-back triangular electrode pair were made based on the analysis of the corresponding sensitivity distributions. The results indicated that the sensitivity distribution could be useful for optimising the probe design parameters and predicting the imaging performance.

  7. Coupling of the simultaneous heat and water model with a distributed hydrological model and evaluation of the combined model in a cold region watershed

    USDA-ARS?s Scientific Manuscript database

    To represent the effects of frozen soil on hydrology in cold regions, a new physically based distributed hydrological model has been developed by coupling the simultaneous heat and water model (SHAW) with the geomorphology based distributed hydrological model (GBHM), under the framework of the water...

  8. Development of a distributed biosphere hydrological model and its evaluation with the Southern Great Plains Experiments (SGP97 and SGP99)

    USDA-ARS?s Scientific Manuscript database

    A distributed biosphere hydrological model, the so called water and energy budget-based distributed hydrological model (WEB-DHM), has been developed by fully coupling a biosphere scheme (SiB2) with a geomorphology-based hydrological model (GBHM). SiB2 describes the transfer of turbulent fluxes (ener...

  9. Distributed Storage Algorithm for Geospatial Image Data Based on Data Access Patterns.

    PubMed

    Pan, Shaoming; Li, Yongkai; Xu, Zhengquan; Chong, Yanwen

    2015-01-01

    Declustering techniques are widely used in distributed environments to reduce query response time through parallel I/O by splitting large files into several small blocks and then distributing those blocks among multiple storage nodes. Unfortunately, however, many small geospatial image data files cannot be further split for distributed storage. In this paper, we propose a complete theoretical system for the distributed storage of small geospatial image data files based on mining the access patterns of geospatial image data using their historical access log information. First, an algorithm is developed to construct an access correlation matrix based on the analysis of the log information, which reveals the patterns of access to the geospatial image data. Then, a practical heuristic algorithm is developed to determine a reasonable solution based on the access correlation matrix. Finally, a number of comparative experiments are presented, demonstrating that our algorithm displays a higher total parallel access probability than those of other algorithms by approximately 10-15% and that the performance can be further improved by more than 20% by simultaneously applying a copy storage strategy. These experiments show that the algorithm can be applied in distributed environments to help realize parallel I/O and thereby improve system performance.

  10. The Application of Observational Practice and Educational Networking in Simulation-Based and Distributed Medical Education Contexts.

    PubMed

    Welsher, Arthur; Rojas, David; Khan, Zain; VanderBeek, Laura; Kapralos, Bill; Grierson, Lawrence E M

    2018-02-01

    Research has revealed that individuals can improve technical skill performance by viewing demonstrations modeled by either expert or novice performers. These findings support the development of video-based observational practice communities that augment simulation-based skill education and connect geographically distributed learners. This study explores the experimental replicability of the observational learning effect when demonstrations are sampled from a community of distributed learners and serves as a context for understanding learner experiences within this type of training protocol. Participants from 3 distributed medical campuses engaged in a simulation-based learning study of the elliptical excision in which they completed a video-recorded performance before being assigned to 1 of 3 groups for a 2-week observational practice intervention. One group observed expert demonstrations, another observed novice demonstrations, and the third observed a combination of both. Participants returned for posttesting immediately and 1 month after the intervention. Participants also engaged in interviews regarding their perceptions of the usability and relevance of video-based observational practice to clinical education. Checklist (P < 0.0001) and global rating (P < 0.0001) measures indicate that participants, regardless of group assignment, improved after the intervention and after a 1-month retention period. Analyses revealed no significant differences between groups. Qualitative analyses indicate that participants perceived the observational practice platform to be usable, relevant, and potentially improved with enhanced feedback delivery. Video-based observational practice involving expert and/or novice demonstrations enhances simulation-based skill learning in a group of geographically distributed trainees. These findings support the use of Internet-mediated observational learning communities in distributed and simulation-based medical education contexts.

  11. [Evoked Potential Blind Extraction Based on Fractional Lower Order Spatial Time-Frequency Matrix].

    PubMed

    Long, Junbo; Wang, Haibin; Zha, Daifeng

    2015-04-01

    The impulsive electroencephalograph (EEG) noises in evoked potential (EP) signals is very strong, usually with a heavy tail and infinite variance characteristics like the acceleration noise impact, hypoxia and etc., as shown in other special tests. The noises can be described by a stable distribution model. In this paper, Wigner-Ville distribution (WVD) and pseudo Wigner-Ville distribution (PWVD) time-frequency distribution based on the fractional lower order moment are presented to be improved. We got fractional lower order WVD (FLO-WVD) and fractional lower order PWVD (FLO-PWVD) time-frequency distribution which could be suitable for a stable distribution process. We also proposed the fractional lower order spatial time-frequency distribution matrix (FLO-STFM) concept. Therefore, combining with time-frequency underdetermined blind source separation (TF-UBSS), we proposed a new fractional lower order spatial time-frequency underdetermined blind source separation (FLO-TF-UBSS) which can work in a stable distribution environment. We used the FLO-TF-UBSS algorithm to extract EPs. Simulations showed that the proposed method could effectively extract EPs in EEG noises, and the separated EPs and EEG signals based on FLO-TF-UBSS were almost the same as the original signal, but blind separation based on TF-UBSS had certain deviation. The correlation coefficient of the FLO-TF-UBSS algorithm was higher than the TF-UBSS algorithm when generalized signal-to-noise ratio (GSNR) changed from 10 dB to 30 dB and a varied from 1. 06 to 1. 94, and was approximately e- qual to 1. Hence, the proposed FLO-TF-UBSS method might be better than the TF-UBSS algorithm based on second order for extracting EP signal under an EEG noise environment.

  12. An Overview of the Source Physics Experiments (SPE) at the Nevada National Security Site (NNSS)

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Barker, D. L.; White, R. L.; Emmitt, R. F.; Townsend, M. J.; Graves, T. E.; Becker, S. A.; Teel, M. G.; Lee, P.; Antoun, T. H.; Rodgers, A.; Walter, W. R.; Mellors, R. J.; Brunish, W. M.; Bradley, C. R.; Patton, H. J.; Hawkins, W. L.; Corbell, B. H.; Abbott, R. E.; SPE Working Group

    2011-12-01

    Modeling of explosion phenomenology has been primarily empirically based when looking at the seismic, infrasound, and acoustic signals. In order to detect low-yield nuclear explosions under the Comprehensive Nuclear Test-Ban Treaty (CTBT), we must be able to understand and model the explosive source in settings beyond where we have empirical data. The Source Physics Experiments (SPE) at the Nevada National Security Site are the first step in this endeavor to link the empirically based with the physics-based modeling to develop this predictive capability. The current series of tests is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the site's expected "simple geology"-the granite is a fairly homogeneous body. In addition, data are available from underground nuclear tests that were conducted in the same rock body, and the nature of the geology has been well-documented. Among the project goals for the SPE is to provide fully coupled seismic energy to the seismic and acoustic seismic arrays so that the transition between the near and far-field data can be modeled and our scientists can begin to understand how non-linear effects and anisotropy control seismic energy transmission and partitioning. The first shot for the SPE was conducted in May 2011 as a calibration shot (SPE1) with 220 lb (100 kg) of chemical explosives set at a depth of 180 ft (55 m). An array of sensors and diagnostics recorded the shot data, including accelerometers, geophones, rotational sensors, short-period and broadband seismic sensors, Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD) as well as infrasound sensors. The three-component accelerometer packages were set at depths of 180 ft (55 m), 150 ft (46 m), and 50 ft (15 m) in two rings around ground zero (GZ); the inner ring was at 10 m and the outer ring was 20 m from GZ. Six sets of surface accelerometers (100 and 500 g) were placed along in an azimuth of SW from GZ every 10 m. Seven infrasound sensors were placed in an array around the GZ, extending from tens of meters to kilometers. Over 100 seismic stations were positioned, most of which were in five radial lines from GZ out to 2 km. Over 400 data channels were recorded for SPE1, and data recovery was about 95% with high signal to noise ratio. Future tests will be conducted in the same shot hole as SPE1. The SPE2 experiment will consist of 2200 lb (1000 kg) of chemical explosives shot at 150 ft (46 m) depth utilizing the above-described instrumentation. Subsequent SPE shots will be the same size, within the same shot hole, and within the damage zone. The ultimate goal of the SPE Project is to develop predictive capability for using seismic energy as a tool for CTBT issues. This work was done by National Security Technologies, LLC, under Contract No. DE AC52 06NA25946 with the U.S. Department of Energy.

  13. The development of intention-based sociomoral judgment and distribution behavior from a third-party stance.

    PubMed

    Li, Jing; Tomasello, Michael

    2018-03-01

    The current study investigated children's intention-based sociomoral judgments and distribution behavior from a third-party stance. An actor puppet showed either positive or negative intention toward a target puppet, which had previously performed a prosocial or antisocial action toward others (i.e., children witnessed various types of indirect reciprocity). Children (3- and 5-year-olds) were asked to make sociomoral judgments and to distribute resources to the actor puppet. Results showed that 5-year-olds were more likely than 3-year-olds to be influenced by intention when they made their judgment and distributed resources. The target's previous actions affected only 5-year-olds' intent-based social preference. These results suggest that children's judgments about intent-based indirect reciprocity develop from ages 3 to 5 years. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Effects of naloxone distribution to likely bystanders: Results of an agent-based model.

    PubMed

    Keane, Christopher; Egan, James E; Hawk, Mary

    2018-05-01

    Opioid overdose deaths in the US rose dramatically in the past 16 years, creating an urgent national health crisis with no signs of immediate relief. In 2017, the President of the US officially declared the opioid epidemic to be a national emergency and called for additional resources to respond to the crisis. Distributing naloxone to community laypersons and people at high risk for opioid overdose can prevent overdose death, but optimal distribution methods have not yet been pinpointed. We conducted a sequential exploratory mixed methods design using qualitative data to inform an agent-based model to improve understanding of effective community-based naloxone distribution to laypersons to reverse opioid overdose. The individuals in the model were endowed with cognitive and behavioral variables and accessed naloxone via community sites such as pharmacies, hospitals, and urgent-care centers. We compared overdose deaths over a simulated 6-month period while varying the number of distribution sites (0, 1, and 10) and number of kits given to individuals per visit (1 versus 10). Specifically, we ran thirty simulations for each of thirteen distribution models and report average overdose deaths for each. The baseline comparator was no naloxone distribution. Our simulations explored the effects of distribution through syringe exchange sites with and without secondary distribution, which refers to distribution of naloxone kits by laypersons within their social networks and enables ten additional laypersons to administer naloxone to reverse opioid overdose. Our baseline model with no naloxone distribution predicted there would be 167.9 deaths in a six month period. A single distribution site, even with 10 kits picked up per visit, decreased overdose deaths by only 8.3% relative to baseline. However, adding secondary distribution through social networks to a single site resulted in 42.5% fewer overdose deaths relative to baseline. That is slightly higher than the 39.9% decrease associated with a tenfold increase in the number of sites, all distributing ten kits but with no secondary distribution. This suggests that, as long as multiple kits are picked up per visit, adding secondary distribution is at least as effective as increasing sites from one to ten. Combining the addition of secondary distribution with an increase in sites from one to ten resulted in a 61.1% drop in deaths relative to the baseline. Adding distribution through a syringe exchange site resulted in a drop of approximately 65% of deaths relative to baseline. In fact, when enabling distribution through a clean-syringe site, the secondary distribution through networks contributed no additional drops in deaths. Community-based naloxone distribution to reverse opioid overdose may significantly reduce deaths. Optimal distribution methods may include secondary distribution so that the person who picks up naloxone kits can enable others in the community to administer naloxone, as well as targeting naloxone distribution to sites where individuals at high-risk for opioid overdose death are likely to visit, such as syringe-exchange programs. This study design, which paired exploratory qualitative data with agent-based modeling, can be used in other settings seeking to implement and improve naloxone distribution programs. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  15. Ontology-Based Multimedia Authoring Tool for Adaptive E-Learning

    ERIC Educational Resources Information Center

    Deng, Lawrence Y.; Keh, Huan-Chao; Liu, Yi-Jen

    2010-01-01

    More video streaming technologies supporting distance learning systems are becoming popular among distributed network environments. In this paper, the authors develop a multimedia authoring tool for adaptive e-learning by using characterization of extended media streaming technologies. The distributed approach is based on an ontology-based model.…

  16. On Nonequivalence of Several Procedures of Structural Equation Modeling

    ERIC Educational Resources Information Center

    Yuan, Ke-Hai; Chan, Wai

    2005-01-01

    The normal theory based maximum likelihood procedure is widely used in structural equation modeling. Three alternatives are: the normal theory based generalized least squares, the normal theory based iteratively reweighted least squares, and the asymptotically distribution-free procedure. When data are normally distributed and the model structure…

  17. Motion/imagery secure cloud enterprise architecture analysis

    NASA Astrophysics Data System (ADS)

    DeLay, John L.

    2012-06-01

    Cloud computing with storage virtualization and new service-oriented architectures brings a new perspective to the aspect of a distributed motion imagery and persistent surveillance enterprise. Our existing research is focused mainly on content management, distributed analytics, WAN distributed cloud networking performance issues of cloud based technologies. The potential of leveraging cloud based technologies for hosting motion imagery, imagery and analytics workflows for DOD and security applications is relatively unexplored. This paper will examine technologies for managing, storing, processing and disseminating motion imagery and imagery within a distributed network environment. Finally, we propose areas for future research in the area of distributed cloud content management enterprises.

  18. Parallel Harmony Search Based Distributed Energy Resource Optimization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ceylan, Oguzhan; Liu, Guodong; Tomsovic, Kevin

    2015-01-01

    This paper presents a harmony search based parallel optimization algorithm to minimize voltage deviations in three phase unbalanced electrical distribution systems and to maximize active power outputs of distributed energy resources (DR). The main contribution is to reduce the adverse impacts on voltage profile during a day as photovoltaics (PVs) output or electrical vehicles (EVs) charging changes throughout a day. The IEEE 123- bus distribution test system is modified by adding DRs and EVs under different load profiles. The simulation results show that by using parallel computing techniques, heuristic methods may be used as an alternative optimization tool in electricalmore » power distribution systems operation.« less

  19. Plant Distribution Data Show Broader Climatic Limits than Expert-Based Climatic Tolerance Estimates

    PubMed Central

    Curtis, Caroline A.; Bradley, Bethany A.

    2016-01-01

    Background Although increasingly sophisticated environmental measures are being applied to species distributions models, the focus remains on using climatic data to provide estimates of habitat suitability. Climatic tolerance estimates based on expert knowledge are available for a wide range of plants via the USDA PLANTS database. We aim to test how climatic tolerance inferred from plant distribution records relates to tolerance estimated by experts. Further, we use this information to identify circumstances when species distributions are more likely to approximate climatic tolerance. Methods We compiled expert knowledge estimates of minimum and maximum precipitation and minimum temperature tolerance for over 1800 conservation plant species from the ‘plant characteristics’ information in the USDA PLANTS database. We derived climatic tolerance from distribution data downloaded from the Global Biodiversity and Information Facility (GBIF) and corresponding climate from WorldClim. We compared expert-derived climatic tolerance to empirical estimates to find the difference between their inferred climate niches (ΔCN), and tested whether ΔCN was influenced by growth form or range size. Results Climate niches calculated from distribution data were significantly broader than expert-based tolerance estimates (Mann-Whitney p values << 0.001). The average plant could tolerate 24 mm lower minimum precipitation, 14 mm higher maximum precipitation, and 7° C lower minimum temperatures based on distribution data relative to expert-based tolerance estimates. Species with larger ranges had greater ΔCN for minimum precipitation and minimum temperature. For maximum precipitation and minimum temperature, forbs and grasses tended to have larger ΔCN while grasses and trees had larger ΔCN for minimum precipitation. Conclusion Our results show that distribution data are consistently broader than USDA PLANTS experts’ knowledge and likely provide more robust estimates of climatic tolerance, especially for widespread forbs and grasses. These findings suggest that widely available expert-based climatic tolerance estimates underrepresent species’ fundamental niche and likely fail to capture the realized niche. PMID:27870859

  20. A Weibull distribution accrual failure detector for cloud computing.

    PubMed

    Liu, Jiaxi; Wu, Zhibo; Wu, Jin; Dong, Jian; Zhao, Yao; Wen, Dongxin

    2017-01-01

    Failure detectors are used to build high availability distributed systems as the fundamental component. To meet the requirement of a complicated large-scale distributed system, accrual failure detectors that can adapt to multiple applications have been studied extensively. However, several implementations of accrual failure detectors do not adapt well to the cloud service environment. To solve this problem, a new accrual failure detector based on Weibull Distribution, called the Weibull Distribution Failure Detector, has been proposed specifically for cloud computing. It can adapt to the dynamic and unexpected network conditions in cloud computing. The performance of the Weibull Distribution Failure Detector is evaluated and compared based on public classical experiment data and cloud computing experiment data. The results show that the Weibull Distribution Failure Detector has better performance in terms of speed and accuracy in unstable scenarios, especially in cloud computing.

  1. A non-stationary cost-benefit based bivariate extreme flood estimation approach

    NASA Astrophysics Data System (ADS)

    Qi, Wei; Liu, Junguo

    2018-02-01

    Cost-benefit analysis and flood frequency analysis have been integrated into a comprehensive framework to estimate cost effective design values. However, previous cost-benefit based extreme flood estimation is based on stationary assumptions and analyze dependent flood variables separately. A Non-Stationary Cost-Benefit based bivariate design flood estimation (NSCOBE) approach is developed in this study to investigate influence of non-stationarities in both the dependence of flood variables and the marginal distributions on extreme flood estimation. The dependence is modeled utilizing copula functions. Previous design flood selection criteria are not suitable for NSCOBE since they ignore time changing dependence of flood variables. Therefore, a risk calculation approach is proposed based on non-stationarities in both marginal probability distributions and copula functions. A case study with 54-year observed data is utilized to illustrate the application of NSCOBE. Results show NSCOBE can effectively integrate non-stationarities in both copula functions and marginal distributions into cost-benefit based design flood estimation. It is also found that there is a trade-off between maximum probability of exceedance calculated from copula functions and marginal distributions. This study for the first time provides a new approach towards a better understanding of influence of non-stationarities in both copula functions and marginal distributions on extreme flood estimation, and could be beneficial to cost-benefit based non-stationary bivariate design flood estimation across the world.

  2. Coordinated control of micro-grid based on distributed moving horizon control.

    PubMed

    Ma, Miaomiao; Shao, Liyang; Liu, Xiangjie

    2018-05-01

    This paper proposed the distributed moving horizon coordinated control scheme for the power balance and economic dispatch problems of micro-grid based on distributed generation. We design the power coordinated controller for each subsystem via moving horizon control by minimizing a suitable objective function. The objective function of distributed moving horizon coordinated controller is chosen based on the principle that wind power subsystem has the priority to generate electricity while photovoltaic power generation coordinates with wind power subsystem and the battery is only activated to meet the load demand when necessary. The simulation results illustrate that the proposed distributed moving horizon coordinated controller can allocate the output power of two generation subsystems reasonably under varying environment conditions, which not only can satisfy the load demand but also limit excessive fluctuations of output power to protect the power generation equipment. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  3. TOPICS IN THEORY OF GENERALIZED PARTON DISTRIBUTIONS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Radyushkin, Anatoly V.

    Several topics in the theory of generalized parton distributions (GPDs) are reviewed. First, we give a brief overview of the basics of the theory of generalized parton distributions and their relationship with simpler phenomenological functions, viz. form factors, parton densities and distribution amplitudes. Then, we discuss recent developments in building models for GPDs that are based on the formalism of double distributions (DDs). A special attention is given to a careful analysis of the singularity structure of DDs. The DD formalism is applied to construction of a model GPDs with a singular Regge behavior. Within the developed DD-based approach, wemore » discuss the structure of GPD sum rules. It is shown that separation of DDs into the so-called ``plus'' part and the $D$-term part may be treated as a renormalization procedure for the GPD sum rules. This approach is compared with an alternative prescription based on analytic regularization.« less

  4. Analysis and numerical simulation research of the heating process in the oven

    NASA Astrophysics Data System (ADS)

    Chen, Yawei; Lei, Dingyou

    2016-10-01

    How to use the oven to bake delicious food is the most concerned problem of the designers and users of the oven. For this intent, this paper analyzed the heat distribution in the oven based on the basic operation principles and proceeded the data simulation of the temperature distribution on the rack section. Constructing the differential equation model of the temperature distribution changes in the pan when the oven works based on the heat radiation and heat transmission, based on the idea of utilizing cellular automation to simulate heat transfer process, used ANSYS software to proceed the numerical simulation analysis to the rectangular, round-cornered rectangular, elliptical and circular pans and giving out the instantaneous temperature distribution of the corresponding shapes of the pans. The temperature distribution of the rectangular and circular pans proves that the product gets overcooked easily at the corners and edges of rectangular pans but not of a round pan.

  5. Classification of Complete Proteomes of Different Organisms and Protein Sets Based on Their Protein Distributions in Terms of Some Key Attributes of Proteins

    DOE PAGES

    Guo, Hao-Bo; Ma, Yue; Tuskan, Gerald A.; ...

    2018-01-01

    The existence of complete genome sequences makes it important to develop different approaches for classification of large-scale data sets and to make extraction of biological insights easier. Here, we propose an approach for classification of complete proteomes/protein sets based on protein distributions on some basic attributes. We demonstrate the usefulness of this approach by determining protein distributions in terms of two attributes: protein lengths and protein intrinsic disorder contents (ID). The protein distributions based on L and ID are surveyed for representative proteome organisms and protein sets from the three domains of life. The two-dimensional maps (designated as fingerprints here)more » from the protein distribution densities in the LD space defined by ln( L ) and ID are then constructed. The fingerprints for different organisms and protein sets are found to be distinct with each other, and they can therefore be used for comparative studies. As a test case, phylogenetic trees have been constructed based on the protein distribution densities in the fingerprints of proteomes of organisms without performing any protein sequence comparison and alignments. The phylogenetic trees generated are biologically meaningful, demonstrating that the protein distributions in the LD space may serve as unique phylogenetic signals of the organisms at the proteome level.« less

  6. Classification of Complete Proteomes of Different Organisms and Protein Sets Based on Their Protein Distributions in Terms of Some Key Attributes of Proteins

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guo, Hao-Bo; Ma, Yue; Tuskan, Gerald A.

    The existence of complete genome sequences makes it important to develop different approaches for classification of large-scale data sets and to make extraction of biological insights easier. Here, we propose an approach for classification of complete proteomes/protein sets based on protein distributions on some basic attributes. We demonstrate the usefulness of this approach by determining protein distributions in terms of two attributes: protein lengths and protein intrinsic disorder contents (ID). The protein distributions based on L and ID are surveyed for representative proteome organisms and protein sets from the three domains of life. The two-dimensional maps (designated as fingerprints here)more » from the protein distribution densities in the LD space defined by ln( L ) and ID are then constructed. The fingerprints for different organisms and protein sets are found to be distinct with each other, and they can therefore be used for comparative studies. As a test case, phylogenetic trees have been constructed based on the protein distribution densities in the fingerprints of proteomes of organisms without performing any protein sequence comparison and alignments. The phylogenetic trees generated are biologically meaningful, demonstrating that the protein distributions in the LD space may serve as unique phylogenetic signals of the organisms at the proteome level.« less

  7. Changes in Urban-Rural Social Structure and Distribution of High School Educational Opportunities--An Analysis Based on Middle School Graduation Education Tracking in Q County, Gansu

    ERIC Educational Resources Information Center

    Baoyan, Yang; Minggang, Wan

    2015-01-01

    To a certain extent, the distribution of high school education opportunities among the population determines the stratification of high school education opportunities. The researchers examined the distribution of high school education opportunities within the county region based on survey data on middle school graduation education tracking in Q…

  8. Distribution of permanent plots to evaluate silvicultural treatments in the Inland Empire

    Treesearch

    John C. Byrne; Albert R. Stage; David L. Renner

    1988-01-01

    To assess the adequacy of a permanent-plot data base for estimating growth and yield, one first needs to know how the plots in the data base are distributed in relation to the population they are presumed to represent. The distribution of permanent plots to study forest growth in the Inland Empire (northeastern Washington, northern Idaho, and western Montana) is...

  9. Distributed Pheromone-Based Swarming Control of Unmanned Air and Ground Vehicles for RSTA

    DTIC Science & Technology

    2008-03-20

    Forthcoming in Proceedings of SPIE Defense & Security Conference, March 2008, Orlando, FL Distributed Pheromone -Based Swarming Control of Unmanned...describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of...onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm

  10. Prediction-based dynamic load-sharing heuristics

    NASA Technical Reports Server (NTRS)

    Goswami, Kumar K.; Devarakonda, Murthy; Iyer, Ravishankar K.

    1993-01-01

    The authors present dynamic load-sharing heuristics that use predicted resource requirements of processes to manage workloads in a distributed system. A previously developed statistical pattern-recognition method is employed for resource prediction. While nonprediction-based heuristics depend on a rapidly changing system status, the new heuristics depend on slowly changing program resource usage patterns. Furthermore, prediction-based heuristics can be more effective since they use future requirements rather than just the current system state. Four prediction-based heuristics, two centralized and two distributed, are presented. Using trace driven simulations, they are compared against random scheduling and two effective nonprediction based heuristics. Results show that the prediction-based centralized heuristics achieve up to 30 percent better response times than the nonprediction centralized heuristic, and that the prediction-based distributed heuristics achieve up to 50 percent improvements relative to their nonprediction counterpart.

  11. Radiolytic preparation of ETFE and PFA based anion exchange membranes for alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Ko, Beom-Seok; Sohn, Joon-Yong; Nho, Young-Chang; Shin, Junhwa

    2011-11-01

    In this study, a versatile monomer, vinylbenzyl chloride (VBC) was radiolytically grafted onto a partially fluorinated ETFE and perfluorinated polymer PFA films. The VBC grafted films were treated with trimethylamine to prepare the alkaline anion exchange membranes (AAEMs). No significant differences in the ion exchange capacities and water uptakes were observed between the ETFE and PFA based AAEMs with similar degree of grafting (DOG). However, the distribution patterns of the graft chains over the cross-section of the ETFE and PFA based AAEMs were found to be quite different; the even distribution was observed from the ETFE based AAEMs while the uneven distribution was observed from the PFA based AAEMs. It was also found that the PFA based AAEMs have the higher ionic conductivity and chemical stability, compared to the ETFE based AAEMs.

  12. Fuzzy-Neural Controller in Service Requests Distribution Broker for SOA-Based Systems

    NASA Astrophysics Data System (ADS)

    Fras, Mariusz; Zatwarnicka, Anna; Zatwarnicki, Krzysztof

    The evolution of software architectures led to the rising importance of the Service Oriented Architecture (SOA) concept. This architecture paradigm support building flexible distributed service systems. In the paper the architecture of service request distribution broker designed for use in SOA-based systems is proposed. The broker is built with idea of fuzzy control. The functional and non-functional request requirements in conjunction with monitoring of execution and communication links are used to distribute requests. Decisions are made with use of fuzzy-neural network.

  13. Distributed software framework and continuous integration in hydroinformatics systems

    NASA Astrophysics Data System (ADS)

    Zhou, Jianzhong; Zhang, Wei; Xie, Mengfei; Lu, Chengwei; Chen, Xiao

    2017-08-01

    When encountering multiple and complicated models, multisource structured and unstructured data, complex requirements analysis, the platform design and integration of hydroinformatics systems become a challenge. To properly solve these problems, we describe a distributed software framework and it’s continuous integration process in hydroinformatics systems. This distributed framework mainly consists of server cluster for models, distributed database, GIS (Geographic Information System) servers, master node and clients. Based on it, a GIS - based decision support system for joint regulating of water quantity and water quality of group lakes in Wuhan China is established.

  14. One Step Quantum Key Distribution Based on EPR Entanglement.

    PubMed

    Li, Jian; Li, Na; Li, Lei-Lei; Wang, Tao

    2016-06-30

    A novel quantum key distribution protocol is presented, based on entanglement and dense coding and allowing asymptotically secure key distribution. Considering the storage time limit of quantum bits, a grouping quantum key distribution protocol is proposed, which overcomes the vulnerability of first protocol and improves the maneuverability. Moreover, a security analysis is given and a simple type of eavesdropper's attack would introduce at least an error rate of 46.875%. Compared with the "Ping-pong" protocol involving two steps, the proposed protocol does not need to store the qubit and only involves one step.

  15. A new distributed systems scheduling algorithm: a swarm intelligence approach

    NASA Astrophysics Data System (ADS)

    Haghi Kashani, Mostafa; Sarvizadeh, Raheleh; Jameii, Mahdi

    2011-12-01

    The scheduling problem in distributed systems is known as an NP-complete problem, and methods based on heuristic or metaheuristic search have been proposed to obtain optimal and suboptimal solutions. The task scheduling is a key factor for distributed systems to gain better performance. In this paper, an efficient method based on memetic algorithm is developed to solve the problem of distributed systems scheduling. With regard to load balancing efficiently, Artificial Bee Colony (ABC) has been applied as local search in the proposed memetic algorithm. The proposed method has been compared to existing memetic-Based approach in which Learning Automata method has been used as local search. The results demonstrated that the proposed method outperform the above mentioned method in terms of communication cost.

  16. A Distributed Ambient Intelligence Based Multi-Agent System for Alzheimer Health Care

    NASA Astrophysics Data System (ADS)

    Tapia, Dante I.; RodríGuez, Sara; Corchado, Juan M.

    This chapter presents ALZ-MAS (Alzheimer multi-agent system), an ambient intelligence (AmI)-based multi-agent system aimed at enhancing the assistance and health care for Alzheimer patients. The system makes use of several context-aware technologies that allow it to automatically obtain information from users and the environment in an evenly distributed way, focusing on the characteristics of ubiquity, awareness, intelligence, mobility, etc., all of which are concepts defined by AmI. ALZ-MAS makes use of a services oriented multi-agent architecture, called flexible user and services oriented multi-agent architecture, to distribute resources and enhance its performance. It is demonstrated that a SOA approach is adequate to build distributed and highly dynamic AmI-based multi-agent systems.

  17. Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks

    PubMed Central

    Lam, William H. K.; Li, Qingquan

    2017-01-01

    Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks. PMID:29210978

  18. Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks.

    PubMed

    Shi, Chaoyang; Chen, Bi Yu; Lam, William H K; Li, Qingquan

    2017-12-06

    Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks.

  19. Development of gravity theory application in the internalregional inter-zone commodity movement distribution with the origin zone movement generation boundary

    NASA Astrophysics Data System (ADS)

    Akbardin, J.; Parikesit, D.; Riyanto, B.; TMulyono, A.

    2018-05-01

    Zones that produce land fishery commodity and its yields have characteristics that is limited in distribution capability because infrastructure conditions availability. High demand for fishery commodities caused to a growing distribution at inefficient distribution distance. The development of the gravity theory with the limitation of movement generation from the production zone can increase the interaction inter-zones by distribution distances effectively and efficiently with shorter movement distribution distances. Regression analysis method with multiple variable of transportation infrastructure condition based on service level and quantitative capacity is determined to estimate the 'mass' of movement generation that is formed. The resulting movement distribution (Tid) model has the equation Tid = 27.04 -0.49 tid. Based on barrier function of power model with calibration value β = 0.0496. In the way of development of the movement generation 'mass' boundary at production zone will shorten the distribution distance effectively with shorter distribution distances. Shorter distribution distances will increase the accessibility inter-zones to interact according to the magnitude of the movement generation 'mass'.

  20. The Potential for Spatial Distribution Indices to Signal Thresholds in Marine Fish Biomass

    PubMed Central

    Reuchlin-Hugenholtz, Emilie

    2015-01-01

    The frequently observed positive relationship between fish population abundance and spatial distribution suggests that changes in distribution can be indicative of trends in abundance. If contractions in spatial distribution precede declines in spawning stock biomass (SSB), spatial distribution reference points could complement the SSB reference points that are commonly used in marine conservation biology and fisheries management. When relevant spatial distribution information is integrated into fisheries management and recovery plans, risks and uncertainties associated with a plan based solely on the SSB criterion would be reduced. To assess the added value of spatial distribution data, we examine the relationship between SSB and four metrics of spatial distribution intended to reflect changes in population range, concentration, and density for 10 demersal populations (9 species) inhabiting the Scotian Shelf, Northwest Atlantic. Our primary purpose is to assess their potential to serve as indices of SSB, using fisheries independent survey data. We find that metrics of density offer the best correlate of spawner biomass. A decline in the frequency of encountering high density areas is associated with, and in a few cases preceded by, rapid declines in SSB in 6 of 10 populations. Density-based indices have considerable potential to serve both as an indicator of SSB and as spatially based reference points in fisheries management. PMID:25789624

  1. Ethnicity-specific birthweight distributions improve identification of term newborns at risk for short-term morbidity.

    PubMed

    Hanley, Gillian E; Janssen, Patricia A

    2013-11-01

    We aimed to determine whether ethnicity-specific birthweight distributions more accurately identify newborns at risk for short-term neonatal morbidity associated with small for gestational age (SGA) birth than population-based distributions not stratified on ethnicity. We examined 100,463 singleton term infants born to parents in Washington State between Jan. 1, 2006, and Dec. 31, 2008. Using multivariable logistic regression models, we compared the ability of an ethnicity-specific growth distribution and a population-based growth distribution to predict which infants were at increased risk for Apgar score <7 at 5 minutes, admission to the neonatal intensive care unit, ventilation, extended length of stay in hospital, hypothermia, hypoglycemia, and infection. Newborns considered SGA by ethnicity-specific weight distributions had the highest rates of each of the adverse outcomes assessed-more than double those of infants only considered SGA by the population-based standards. When controlling for mother's age, parity, body mass index, education, gestational age, mode of delivery, and marital status, newborns considered SGA by ethnicity-specific birthweight distributions were between 2 and 7 times more likely to suffer from the adverse outcomes listed above than infants who were not SGA. In contrast, newborns considered SGA by population-based birthweight distributions alone were at no higher risk of any adverse outcome except hypothermia (adjusted odds ratio, 2.76; 95% confidence interval, 1.68-4.55) and neonatal intensive care unit admission (adjusted odds ratio, 1.40; 95% confidence interval, 1.18-1.67). Ethnicity-specific birthweight distributions were significantly better at identifying the infants at higher risk of short-term neonatal morbidity, suggesting that their use could save resources and unnecessary parental anxiety. Copyright © 2013 Mosby, Inc. All rights reserved.

  2. NHPP-Based Software Reliability Models Using Equilibrium Distribution

    NASA Astrophysics Data System (ADS)

    Xiao, Xiao; Okamura, Hiroyuki; Dohi, Tadashi

    Non-homogeneous Poisson processes (NHPPs) have gained much popularity in actual software testing phases to estimate the software reliability, the number of remaining faults in software and the software release timing. In this paper, we propose a new modeling approach for the NHPP-based software reliability models (SRMs) to describe the stochastic behavior of software fault-detection processes. The fundamental idea is to apply the equilibrium distribution to the fault-detection time distribution in NHPP-based modeling. We also develop efficient parameter estimation procedures for the proposed NHPP-based SRMs. Through numerical experiments, it can be concluded that the proposed NHPP-based SRMs outperform the existing ones in many data sets from the perspective of goodness-of-fit and prediction performance.

  3. Instructional Designers' Media Selection Practices for Distributed Problem-Based Learning Environments

    ERIC Educational Resources Information Center

    Fells, Stephanie

    2012-01-01

    The design of online or distributed problem-based learning (dPBL) is a nascent, complex design problem. Instructional designers are challenged to effectively unite the constructivist principles of problem-based learning (PBL) with appropriate media in order to create quality dPBL environments. While computer-mediated communication (CMC) tools and…

  4. Virtual Sensor Web Architecture

    NASA Astrophysics Data System (ADS)

    Bose, P.; Zimdars, A.; Hurlburt, N.; Doug, S.

    2006-12-01

    NASA envisions the development of smart sensor webs, intelligent and integrated observation network that harness distributed sensing assets, their associated continuous and complex data sets, and predictive observation processing mechanisms for timely, collaborative hazard mitigation and enhanced science productivity and reliability. This paper presents Virtual Sensor Web Infrastructure for Collaborative Science (VSICS) Architecture for sustained coordination of (numerical and distributed) model-based processing, closed-loop resource allocation, and observation planning. VSICS's key ideas include i) rich descriptions of sensors as services based on semantic markup languages like OWL and SensorML; ii) service-oriented workflow composition and repair for simple and ensemble models; event-driven workflow execution based on event-based and distributed workflow management mechanisms; and iii) development of autonomous model interaction management capabilities providing closed-loop control of collection resources driven by competing targeted observation needs. We present results from initial work on collaborative science processing involving distributed services (COSEC framework) that is being extended to create VSICS.

  5. An extended continuous estimation of distribution algorithm for solving the permutation flow-shop scheduling problem

    NASA Astrophysics Data System (ADS)

    Shao, Zhongshi; Pi, Dechang; Shao, Weishi

    2017-11-01

    This article proposes an extended continuous estimation of distribution algorithm (ECEDA) to solve the permutation flow-shop scheduling problem (PFSP). In ECEDA, to make a continuous estimation of distribution algorithm (EDA) suitable for the PFSP, the largest order value rule is applied to convert continuous vectors to discrete job permutations. A probabilistic model based on a mixed Gaussian and Cauchy distribution is built to maintain the exploration ability of the EDA. Two effective local search methods, i.e. revolver-based variable neighbourhood search and Hénon chaotic-based local search, are designed and incorporated into the EDA to enhance the local exploitation. The parameters of the proposed ECEDA are calibrated by means of a design of experiments approach. Simulation results and comparisons based on some benchmark instances show the efficiency of the proposed algorithm for solving the PFSP.

  6. A novel multitarget model of radiation-induced cell killing based on the Gaussian distribution.

    PubMed

    Zhao, Lei; Mi, Dong; Sun, Yeqing

    2017-05-07

    The multitarget version of the traditional target theory based on the Poisson distribution is still used to describe the dose-survival curves of cells after ionizing radiation in radiobiology and radiotherapy. However, noting that the usual ionizing radiation damage is the result of two sequential stochastic processes, the probability distribution of the damage number per cell should follow a compound Poisson distribution, like e.g. Neyman's distribution of type A (N. A.). In consideration of that the Gaussian distribution can be considered as the approximation of the N. A. in the case of high flux, a multitarget model based on the Gaussian distribution is proposed to describe the cell inactivation effects in low linear energy transfer (LET) radiation with high dose-rate. Theoretical analysis and experimental data fitting indicate that the present theory is superior to the traditional multitarget model and similar to the Linear - Quadratic (LQ) model in describing the biological effects of low-LET radiation with high dose-rate, and the parameter ratio in the present model can be used as an alternative indicator to reflect the radiation damage and radiosensitivity of the cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Emulation of Industrial Control Field Device Protocols

    DTIC Science & Technology

    2013-03-01

    platforms such as the Arduino ( based on the Atmel AVR architecture) or popular PIC architecture based devices, which are programmed for specific functions...UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base , Ohio DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION...confidence intervals for the mean. Based on these results, extensive knowledge of the specific implementations of the protocols or timing profiles of the

  8. Evaluation of community-based continuous distribution of long-lasting insecticide-treated nets in Toamasina II District, Madagascar.

    PubMed

    de Beyl, Celine Zegers; Kilian, Albert; Brown, Andrea; Sy-Ar, Mohamad; Selby, Richmond Ato; Randriamanantenasoa, Felicien; Ranaivosoa, Jocelyn; Zigirumugabe, Sixte; Gerberg, Lilia; Fotheringham, Megan; Lynch, Matthew; Koenker, Hannah

    2017-08-10

    Continuous distribution of insecticide-treated nets (ITNs) is thought to be an effective mechanism to maintain ITN ownership and access between or in the absence of mass campaigns, but evidence is limited. A community-based ITN distribution pilot was implemented and evaluated in Toamasina II District, Madagascar, to assess this new channel for continuous ITN distribution. Beginning 9 months after the December 2012 mass campaign, a community-based distribution pilot ran for an additional 9 months, from September 2013 to June 2014. Households requested ITN coupons from community agents in their village. After verification by the agents, households exchanged the coupon for an ITN at a distribution point. The evaluation was a two-stage cluster survey with a sample size of 1125 households. Counterfactual ITN ownership and access were calculated by excluding ITNs received through the community pilot. At the end of the pilot, household ownership of any ITN was 96.5%, population access to ITN was 81.5 and 61.5% of households owned at least 1 ITN for every 2 people. Without the ITNs provided through the community channel, household ownership of any ITN was estimated at 74.6%, population access to an ITN at 55.5%, and households that owned at least 1 ITN for 2 people at only 34.7%, 18 months after the 2012 campaign. Ownership of community-distributed ITNs was higher among the poorest wealth quintiles. Over 80% of respondents felt the community scheme was fair and simple to use. Household ITN ownership and population ITN access exceeded RBM targets after the 9-month community distribution pilot. The pilot successfully provided coupons and ITNs to households requesting them, particularly for the least poor wealth quintiles, and the scheme was well-perceived by communities. Further research is needed to determine whether community-based distribution can sustain ITN ownership and access over the long term, how continuous availability of ITNs affects household net replacement behaviour, and whether community-based distribution is cost-effective when combined with mass campaigns, or if used with other continuous channels instead of mass campaigns.

  9. Recent progress in distributed optical fiber Raman photon sensors at China Jiliang University

    NASA Astrophysics Data System (ADS)

    Zhang, Zaixuan; Wang, Jianfeng; Li, Yi; Gong, Huaping; Yu, Xiangdong; Liu, Honglin; Jin, Yongxing; Kang, Juan; Li, Chenxia; Zhang, Wensheng; Zhang, Wenping; Niu, Xiaohui; Sun, Zhongzhou; Zhao, Chunliu; Dong, Xinyong; Jin, Shangzhong

    2012-06-01

    A brief review of recent progress in researches, productions and applications of full distributed fiber Raman photon sensors at China Jiliang University (CJLU) is presented. In order to improve the measurement distance, the accuracy, the space resolution, the ability of multi-parameter measurements, and the intelligence of full distributed fiber sensor systems, a new generation fiber sensor technology based on the optical fiber nonlinear scattering fusion principle is proposed. A series of new generation full distributed fiber sensors are investigated and designed, which consist of new generation ultra-long distance full distributed fiber Raman and Rayleigh scattering photon sensors integrated with a fiber Raman amplifier, auto-correction full distributed fiber Raman photon temperature sensors based on Raman correlation dual sources, full distributed fiber Raman photon temperature sensors based on a pulse coding source, full distributed fiber Raman photon temperature sensors using a fiber Raman wavelength shifter, a new type of Brillouin optical time domain analyzers (BOTDAs) integrated with a fiber Raman amplifier for replacing a fiber Brillouin amplifier, full distributed fiber Raman and Brillouin photon sensors integrated with a fiber Raman amplifier, and full distributed fiber Brillouin photon sensors integrated with a fiber Brillouin frequency shifter. The Internet of things is believed as one of candidates of the next technological revolution, which has driven hundreds of millions of class markets. Sensor networks are important components of the Internet of things. The full distributed optical fiber sensor network (Rayleigh, Raman, and Brillouin scattering) is a 3S (smart materials, smart structure, and smart skill) system, which is easy to construct smart fiber sensor networks. The distributed optical fiber sensor can be embedded in the power grids, railways, bridges, tunnels, roads, constructions, water supply systems, dams, oil and gas pipelines and other facilities, and can be integrated with wireless networks.

  10. A Weibull distribution accrual failure detector for cloud computing

    PubMed Central

    Wu, Zhibo; Wu, Jin; Zhao, Yao; Wen, Dongxin

    2017-01-01

    Failure detectors are used to build high availability distributed systems as the fundamental component. To meet the requirement of a complicated large-scale distributed system, accrual failure detectors that can adapt to multiple applications have been studied extensively. However, several implementations of accrual failure detectors do not adapt well to the cloud service environment. To solve this problem, a new accrual failure detector based on Weibull Distribution, called the Weibull Distribution Failure Detector, has been proposed specifically for cloud computing. It can adapt to the dynamic and unexpected network conditions in cloud computing. The performance of the Weibull Distribution Failure Detector is evaluated and compared based on public classical experiment data and cloud computing experiment data. The results show that the Weibull Distribution Failure Detector has better performance in terms of speed and accuracy in unstable scenarios, especially in cloud computing. PMID:28278229

  11. How required reserve ratio affects distribution and velocity of money

    NASA Astrophysics Data System (ADS)

    Xi, Ning; Ding, Ning; Wang, Yougui

    2005-11-01

    In this paper the dependence of wealth distribution and the velocity of money on the required reserve ratio is examined based on a random transfer model of money and computer simulations. A fractional reserve banking system is introduced to the model where money creation can be achieved by bank loans and the monetary aggregate is determined by the monetary base and the required reserve ratio. It is shown that monetary wealth follows asymmetric Laplace distribution and latency time of money follows exponential distribution. The expression of monetary wealth distribution and that of the velocity of money in terms of the required reserve ratio are presented in a good agreement with simulation results.

  12. Real-time modeling of heat distributions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hamann, Hendrik F.; Li, Hongfei; Yarlanki, Srinivas

    Techniques for real-time modeling temperature distributions based on streaming sensor data are provided. In one aspect, a method for creating a three-dimensional temperature distribution model for a room having a floor and a ceiling is provided. The method includes the following steps. A ceiling temperature distribution in the room is determined. A floor temperature distribution in the room is determined. An interpolation between the ceiling temperature distribution and the floor temperature distribution is used to obtain the three-dimensional temperature distribution model for the room.

  13. An Improved Algorithm to Generate a Wi-Fi Fingerprint Database for Indoor Positioning

    PubMed Central

    Chen, Lina; Li, Binghao; Zhao, Kai; Rizos, Chris; Zheng, Zhengqi

    2013-01-01

    The major problem of Wi-Fi fingerprint-based positioning technology is the signal strength fingerprint database creation and maintenance. The significant temporal variation of received signal strength (RSS) is the main factor responsible for the positioning error. A probabilistic approach can be used, but the RSS distribution is required. The Gaussian distribution or an empirically-derived distribution (histogram) is typically used. However, these distributions are either not always correct or require a large amount of data for each reference point. Double peaks of the RSS distribution have been observed in experiments at some reference points. In this paper a new algorithm based on an improved double-peak Gaussian distribution is proposed. Kurtosis testing is used to decide if this new distribution, or the normal Gaussian distribution, should be applied. Test results show that the proposed algorithm can significantly improve the positioning accuracy, as well as reduce the workload of the off-line data training phase. PMID:23966197

  14. An improved algorithm to generate a Wi-Fi fingerprint database for indoor positioning.

    PubMed

    Chen, Lina; Li, Binghao; Zhao, Kai; Rizos, Chris; Zheng, Zhengqi

    2013-08-21

    The major problem of Wi-Fi fingerprint-based positioning technology is the signal strength fingerprint database creation and maintenance. The significant temporal variation of received signal strength (RSS) is the main factor responsible for the positioning error. A probabilistic approach can be used, but the RSS distribution is required. The Gaussian distribution or an empirically-derived distribution (histogram) is typically used. However, these distributions are either not always correct or require a large amount of data for each reference point. Double peaks of the RSS distribution have been observed in experiments at some reference points. In this paper a new algorithm based on an improved double-peak Gaussian distribution is proposed. Kurtosis testing is used to decide if this new distribution, or the normal Gaussian distribution, should be applied. Test results show that the proposed algorithm can significantly improve the positioning accuracy, as well as reduce the workload of the off-line data training phase.

  15. Selective intra-dinucleotide interactions and periodicities of bases separated by K sites: a new vision and tool for phylogeny analyses.

    PubMed

    Valenzuela, Carlos Y

    2017-02-13

    Direct tests of the random or non-random distribution of nucleotides on genomes have been devised to test the hypothesis of neutral, nearly-neutral or selective evolution. These tests are based on the direct base distribution and are independent of the functional (coding or non-coding) or structural (repeated or unique sequences) properties of the DNA. The first approach described the longitudinal distribution of bases in tandem repeats under the Bose-Einstein statistics. A huge deviation from randomness was found. A second approach was the study of the base distribution within dinucleotides whose bases were separated by 0, 1, 2… K nucleotides. Again an enormous difference from the random distribution was found with significances out of tables and programs. These test values were periodical and included the 16 dinucleotides. For example a high "positive" (more observed than expected dinucleotides) value, found in dinucleotides whose bases were separated by (3K + 2) sites, was preceded by two smaller "negative" (less observed than expected dinucleotides) values, whose bases were separated by (3K) or (3K + 1) sites. We examined mtDNAs, prokaryote genomes and some eukaryote chromosomes and found that the significant non-random interactions and periodicities were present up to 1000 or more sites of base separation and in human chromosome 21 until separations of more than 10 millions sites. Each nucleotide has its own significant value of its distance to neutrality; this yields 16 hierarchical significances. A three dimensional table with the number of sites of separation between the bases and the 16 significances (the third dimension is the dinucleotide, individual or taxon involved) gives directly an evolutionary state of the analyzed genome that can be used to obtain phylogenies. An example is provided.

  16. Measurement of total acid number (TAN) and TAN boiling point distribution in petroleum products by electrospray ionization mass spectrometry.

    PubMed

    Qian, Kuangnan; Edwards, Kathleen E; Dechert, Gary J; Jaffe, Stephen B; Green, Larry A; Olmstead, William N

    2008-02-01

    We report a new method for rapid measurement of total acid number (TAN) and TAN boiling point (BP) distribution for petroleum crude and products. The technology is based on negative ion electrospray ionization mass spectrometry (ESI-MS) for selective ionization of petroleum acid and quantification of acid structures and molecular weight distributions. A chip-based nanoelectrospray system enables microscale (<200 mg) and higher throughput (20 samples/h) measurement. Naphthenic acid structures were assigned based on nominal masses of a set of predefined acid structures. Stearic acid is used as an internal standard to calibrate ESI-MS response factors for quantification purposes. With the use of structure-property correlations, boiling point distributions of TAN values can be calculated from the composition. The rapid measurement of TAN BP distributions by ESI is demonstrated for a series of high-TAN crudes and distillation cuts. TAN values determined by the technique agree well with those by the titration method. The distributed properties compare favorably with those measured by distillation and measurement of TAN of corresponding cuts.

  17. Power System Information Delivering System Based on Distributed Object

    NASA Astrophysics Data System (ADS)

    Tanaka, Tatsuji; Tsuchiya, Takehiko; Tamura, Setsuo; Seki, Tomomichi; Kubota, Kenji

    In recent years, improvement in computer performance and development of computer network technology or the distributed information processing technology has a remarkable thing. Moreover, the deregulation is starting and will be spreading in the electric power industry in Japan. Consequently, power suppliers are required to supply low cost power with high quality services to customers. Corresponding to these movements the authors have been proposed SCOPE (System Configuration Of PowEr control system) architecture for distributed EMS/SCADA (Energy Management Systems / Supervisory Control and Data Acquisition) system based on distributed object technology, which offers the flexibility and expandability adapting those movements. In this paper, the authors introduce a prototype of the power system information delivering system, which was developed based on SCOPE architecture. This paper describes the architecture and the evaluation results of this prototype system. The power system information delivering system supplies useful power systems information such as electric power failures to the customers using Internet and distributed object technology. This system is new type of SCADA system which monitors failure of power transmission system and power distribution system with geographic information integrated way.

  18. Multi-user distribution of polarization entangled photon pairs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Trapateau, J.; Orieux, A.; Diamanti, E.

    We experimentally demonstrate multi-user distribution of polarization entanglement using commercial telecom wavelength division demultiplexers. The entangled photon pairs are generated from a broadband source based on spontaneous parametric down conversion in a periodically poled lithium niobate crystal using a double path setup employing a Michelson interferometer and active phase stabilisation. We test and compare demultiplexers based on various technologies and analyze the effect of their characteristics, such as losses and polarization dependence, on the quality of the distributed entanglement for three channel pairs of each demultiplexer. In all cases, we obtain a Bell inequality violation, whose value depends on themore » demultiplexer features. This demonstrates that entanglement can be distributed to at least three user pairs of a network from a single source. Additionally, we verify for the best demultiplexer that the violation is maintained when the pairs are distributed over a total channel attenuation corresponding to 20 km of optical fiber. These techniques are therefore suitable for resource-efficient practical implementations of entanglement-based quantum key distribution and other quantum communication network applications.« less

  19. Evaluating visibility of age spot and freckle based on simulated spectral reflectance distribution and facial color image

    NASA Astrophysics Data System (ADS)

    Hirose, Misa; Toyota, Saori; Tsumura, Norimichi

    2018-02-01

    In this research, we evaluate the visibility of age spot and freckle with changing the blood volume based on simulated spectral reflectance distribution and the actual facial color images, and compare these results. First, we generate three types of spatial distribution of age spot and freckle in patch-like images based on the simulated spectral reflectance. The spectral reflectance is simulated using Monte Carlo simulation of light transport in multi-layered tissue. Next, we reconstruct the facial color image with changing the blood volume. We acquire the concentration distribution of melanin, hemoglobin and shading components by applying the independent component analysis on a facial color image. We reproduce images using the obtained melanin and shading concentration and the changed hemoglobin concentration. Finally, we evaluate the visibility of pigmentations using simulated spectral reflectance distribution and facial color images. In the result of simulated spectral reflectance distribution, we found that the visibility became lower as the blood volume increases. However, we can see that a specific blood volume reduces the visibility of the actual pigmentations from the result of the facial color images.

  20. Knowledge-base browsing: an application of hybrid distributed/local connectionist networks

    NASA Astrophysics Data System (ADS)

    Samad, Tariq; Israel, Peggy

    1990-08-01

    We describe a knowledge base browser based on a connectionist (or neural network) architecture that employs both distributed and local representations. The distributed representations are used for input and output thereby enabling associative noise-tolerant interaction with the environment. Internally all representations are fully local. This simplifies weight assignment and facilitates network configuration for specific applications. In our browser concepts and relations in a knowledge base are represented using " microfeatures. " The microfeatures can encode semantic attributes structural features contextual information etc. Desired portions of the knowledge base can then be associatively retrieved based on a structured cue. An ordered list of partial matches is presented to the user for selection. Microfeatures can also be used as " bookmarks" they can be placed dynamically at appropriate points in the knowledge base and subsequently used as retrieval cues. A proof-of-concept system has been implemented for an internally developed Honeywell-proprietary knowledge acquisition tool. 1.

  1. Identifying and individuating cognitive systems: a task-based distributed cognition alternative to agent-based extended cognition.

    PubMed

    Davies, Jim; Michaelian, Kourken

    2016-08-01

    This article argues for a task-based approach to identifying and individuating cognitive systems. The agent-based extended cognition approach faces a problem of cognitive bloat and has difficulty accommodating both sub-individual cognitive systems ("scaling down") and some supra-individual cognitive systems ("scaling up"). The standard distributed cognition approach can accommodate a wider variety of supra-individual systems but likewise has difficulties with sub-individual systems and faces the problem of cognitive bloat. We develop a task-based variant of distributed cognition designed to scale up and down smoothly while providing a principled means of avoiding cognitive bloat. The advantages of the task-based approach are illustrated by means of two parallel case studies: re-representation in the human visual system and in a biomedical engineering laboratory.

  2. Distributed Prognostics based on Structural Model Decomposition

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew J.; Bregon, Anibal; Roychoudhury, I.

    2014-01-01

    Within systems health management, prognostics focuses on predicting the remaining useful life of a system. In the model-based prognostics paradigm, physics-based models are constructed that describe the operation of a system and how it fails. Such approaches consist of an estimation phase, in which the health state of the system is first identified, and a prediction phase, in which the health state is projected forward in time to determine the end of life. Centralized solutions to these problems are often computationally expensive, do not scale well as the size of the system grows, and introduce a single point of failure. In this paper, we propose a novel distributed model-based prognostics scheme that formally describes how to decompose both the estimation and prediction problems into independent local subproblems whose solutions may be easily composed into a global solution. The decomposition of the prognostics problem is achieved through structural decomposition of the underlying models. The decomposition algorithm creates from the global system model a set of local submodels suitable for prognostics. Independent local estimation and prediction problems are formed based on these local submodels, resulting in a scalable distributed prognostics approach that allows the local subproblems to be solved in parallel, thus offering increases in computational efficiency. Using a centrifugal pump as a case study, we perform a number of simulation-based experiments to demonstrate the distributed approach, compare the performance with a centralized approach, and establish its scalability. Index Terms-model-based prognostics, distributed prognostics, structural model decomposition ABBREVIATIONS

  3. Improving flood forecasting capability of physically based distributed hydrological model by parameter optimization

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Li, J.; Xu, H.

    2015-10-01

    Physically based distributed hydrological models discrete the terrain of the whole catchment into a number of grid cells at fine resolution, and assimilate different terrain data and precipitation to different cells, and are regarded to have the potential to improve the catchment hydrological processes simulation and prediction capability. In the early stage, physically based distributed hydrological models are assumed to derive model parameters from the terrain properties directly, so there is no need to calibrate model parameters, but unfortunately, the uncertanties associated with this model parameter deriving is very high, which impacted their application in flood forecasting, so parameter optimization may also be necessary. There are two main purposes for this study, the first is to propose a parameter optimization method for physically based distributed hydrological models in catchment flood forecasting by using PSO algorithm and to test its competence and to improve its performances, the second is to explore the possibility of improving physically based distributed hydrological models capability in cathcment flood forecasting by parameter optimization. In this paper, based on the scalar concept, a general framework for parameter optimization of the PBDHMs for catchment flood forecasting is first proposed that could be used for all PBDHMs. Then, with Liuxihe model as the study model, which is a physically based distributed hydrological model proposed for catchment flood forecasting, the improverd Particle Swarm Optimization (PSO) algorithm is developed for the parameter optimization of Liuxihe model in catchment flood forecasting, the improvements include to adopt the linear decreasing inertia weight strategy to change the inertia weight, and the arccosine function strategy to adjust the acceleration coefficients. This method has been tested in two catchments in southern China with different sizes, and the results show that the improved PSO algorithm could be used for Liuxihe model parameter optimization effectively, and could improve the model capability largely in catchment flood forecasting, thus proven that parameter optimization is necessary to improve the flood forecasting capability of physically based distributed hydrological model. It also has been found that the appropriate particle number and the maximum evolution number of PSO algorithm used for Liuxihe model catchment flood forcasting is 20 and 30, respectively.

  4. Defining Equivalence in Medical Education Evaluation and Research: Does a Distribution-Based Approach Work?

    ERIC Educational Resources Information Center

    Rusticus, Shayna A.; Eva, Kevin W.

    2016-01-01

    Educators often seek to demonstrate the equivalence of groups, such as whether or not students achieve comparable success regardless of the site at which they trained. A methodological consideration that is often underappreciated is how to operationalize equivalence. This study examined whether a distribution-based approach, based on effect size,…

  5. Combining Probability Distributions of Wind Waves and Sea Level Variations to Assess Return Periods of Coastal Floods

    NASA Astrophysics Data System (ADS)

    Leijala, U.; Bjorkqvist, J. V.; Pellikka, H.; Johansson, M. M.; Kahma, K. K.

    2017-12-01

    Predicting the behaviour of the joint effect of sea level and wind waves is of great significance due to the major impact of flooding events in densely populated coastal regions. As mean sea level rises, the effect of sea level variations accompanied by the waves will be even more harmful in the future. The main challenge when evaluating the effect of waves and sea level variations is that long time series of both variables rarely exist. Wave statistics are also highly location-dependent, thus requiring wave buoy measurements and/or high-resolution wave modelling. As an initial approximation of the joint effect, the variables may be treated as independent random variables, to achieve the probability distribution of their sum. We present results of a case study based on three probability distributions: 1) wave run-up constructed from individual wave buoy measurements, 2) short-term sea level variability based on tide gauge data, and 3) mean sea level projections based on up-to-date regional scenarios. The wave measurements were conducted during 2012-2014 on the coast of city of Helsinki located in the Gulf of Finland in the Baltic Sea. The short-term sea level distribution contains the last 30 years (1986-2015) of hourly data from Helsinki tide gauge, and the mean sea level projections are scenarios adjusted for the Gulf of Finland. Additionally, we present a sensitivity test based on six different theoretical wave height distributions representing different wave behaviour in relation to sea level variations. As these wave distributions are merged with one common sea level distribution, we can study how the different shapes of the wave height distribution affect the distribution of the sum, and which one of the components is dominating under different wave conditions. As an outcome of the method, we obtain a probability distribution of the maximum elevation of the continuous water mass, which enables a flexible tool for evaluating different risk levels in the current and future climate.

  6. Distribution pattern of public transport passenger in Yogyakarta, Indonesia

    NASA Astrophysics Data System (ADS)

    Narendra, Alfa; Malkhamah, Siti; Sopha, Bertha Maya

    2018-03-01

    The arrival and departure distribution pattern of Trans Jogja bus passenger is one of the fundamental model for simulation. The purpose of this paper is to build models of passengers flows. This research used passengers data from January to May 2014. There is no policy that change the operation system affecting the nature of this pattern nowadays. The roads, buses, land uses, schedule, and people are relatively still the same. The data then categorized based on the direction, days, and location. Moreover, each category was fitted into some well-known discrete distributions. Those distributions are compared based on its AIC value and BIC. The chosen distribution model has the smallest AIC and BIC value and the negative binomial distribution found has the smallest AIC and BIC value. Probability mass function (PMF) plots of those models were compared to draw generic model from each categorical negative binomial distribution models. The value of accepted generic negative binomial distribution is 0.7064 and 1.4504 of mu. The minimum and maximum passenger vector value of distribution are is 0 and 41.

  7. Neural network-based distributed attitude coordination control for spacecraft formation flying with input saturation.

    PubMed

    Zou, An-Min; Kumar, Krishna Dev

    2012-07-01

    This brief considers the attitude coordination control problem for spacecraft formation flying when only a subset of the group members has access to the common reference attitude. A quaternion-based distributed attitude coordination control scheme is proposed with consideration of the input saturation and with the aid of the sliding-mode observer, separation principle theorem, Chebyshev neural networks, smooth projection algorithm, and robust control technique. Using graph theory and a Lyapunov-based approach, it is shown that the distributed controller can guarantee the attitude of all spacecraft to converge to a common time-varying reference attitude when the reference attitude is available only to a portion of the group of spacecraft. Numerical simulations are presented to demonstrate the performance of the proposed distributed controller.

  8. Incorporating linguistic knowledge for learning distributed word representations.

    PubMed

    Wang, Yan; Liu, Zhiyuan; Sun, Maosong

    2015-01-01

    Combined with neural language models, distributed word representations achieve significant advantages in computational linguistics and text mining. Most existing models estimate distributed word vectors from large-scale data in an unsupervised fashion, which, however, do not take rich linguistic knowledge into consideration. Linguistic knowledge can be represented as either link-based knowledge or preference-based knowledge, and we propose knowledge regularized word representation models (KRWR) to incorporate these prior knowledge for learning distributed word representations. Experiment results demonstrate that our estimated word representation achieves better performance in task of semantic relatedness ranking. This indicates that our methods can efficiently encode both prior knowledge from knowledge bases and statistical knowledge from large-scale text corpora into a unified word representation model, which will benefit many tasks in text mining.

  9. Incorporating Linguistic Knowledge for Learning Distributed Word Representations

    PubMed Central

    Wang, Yan; Liu, Zhiyuan; Sun, Maosong

    2015-01-01

    Combined with neural language models, distributed word representations achieve significant advantages in computational linguistics and text mining. Most existing models estimate distributed word vectors from large-scale data in an unsupervised fashion, which, however, do not take rich linguistic knowledge into consideration. Linguistic knowledge can be represented as either link-based knowledge or preference-based knowledge, and we propose knowledge regularized word representation models (KRWR) to incorporate these prior knowledge for learning distributed word representations. Experiment results demonstrate that our estimated word representation achieves better performance in task of semantic relatedness ranking. This indicates that our methods can efficiently encode both prior knowledge from knowledge bases and statistical knowledge from large-scale text corpora into a unified word representation model, which will benefit many tasks in text mining. PMID:25874581

  10. Integration of Geographical Information Systems and Geophysical Applications with Distributed Computing Technologies.

    NASA Astrophysics Data System (ADS)

    Pierce, M. E.; Aktas, M. S.; Aydin, G.; Fox, G. C.; Gadgil, H.; Sayar, A.

    2005-12-01

    We examine the application of Web Service Architectures and Grid-based distributed computing technologies to geophysics and geo-informatics. We are particularly interested in the integration of Geographical Information System (GIS) services with distributed data mining applications. GIS services provide the general purpose framework for building archival data services, real time streaming data services, and map-based visualization services that may be integrated with data mining and other applications through the use of distributed messaging systems and Web Service orchestration tools. Building upon on our previous work in these areas, we present our current research efforts. These include fundamental investigations into increasing XML-based Web service performance, supporting real time data streams, and integrating GIS mapping tools with audio/video collaboration systems for shared display and annotation.

  11. Modeling and experiments of the adhesion force distribution between particles and a surface.

    PubMed

    You, Siming; Wan, Man Pun

    2014-06-17

    Due to the existence of surface roughness in real surfaces, the adhesion force between particles and the surface where the particles are deposited exhibits certain statistical distributions. Despite the importance of adhesion force distribution in a variety of applications, the current understanding of modeling adhesion force distribution is still limited. In this work, an adhesion force distribution model based on integrating the root-mean-square (RMS) roughness distribution (i.e., the variation of RMS roughness on the surface in terms of location) into recently proposed mean adhesion force models was proposed. The integration was accomplished by statistical analysis and Monte Carlo simulation. A series of centrifuge experiments were conducted to measure the adhesion force distributions between polystyrene particles (146.1 ± 1.99 μm) and various substrates (stainless steel, aluminum and plastic, respectively). The proposed model was validated against the measured adhesion force distributions from this work and another previous study. Based on the proposed model, the effect of RMS roughness distribution on the adhesion force distribution of particles on a rough surface was explored, showing that both the median and standard deviation of adhesion force distribution could be affected by the RMS roughness distribution. The proposed model could predict both van der Waals force and capillary force distributions and consider the multiscale roughness feature, greatly extending the current capability of adhesion force distribution prediction.

  12. An Intelligent System for Document Retrieval in Distributed Office Environments.

    ERIC Educational Resources Information Center

    Mukhopadhyay, Uttam; And Others

    1986-01-01

    MINDS (Multiple Intelligent Node Document Servers) is a distributed system of knowledge-based query engines for efficiently retrieving multimedia documents in an office environment of distributed workstations. By learning document distribution patterns and user interests and preferences during system usage, it customizes document retrievals for…

  13. Photoacoustic imaging to assess pixel-based sO2 distributions in experimental prostate tumors.

    PubMed

    Bendinger, Alina L; Glowa, Christin; Peter, Jörg; Karger, Christian P

    2018-03-01

    A protocol for photoacoustic imaging (PAI) has been developed to assess pixel-based oxygen saturation (sO2) distributions of experimental tumor models. The protocol was applied to evaluate the dependence of PAI results on measurement settings, reproducibility of PAI, and for the characterization of the oxygenation status of experimental prostate tumor sublines (Dunning R3327-H, -HI, -AT1) implanted subcutaneously in male Copenhagen rats. The three-dimensional (3-D) PA data employing two wavelengths were used to estimate sO2 distributions. If the PA signal was sufficiently strong, the distributions were independent from signal gain, threshold, and positioning of animals. Reproducibility of sO2 distributions with respect to shape and median values was demonstrated over several days. The three tumor sublines were characterized by the shapes of their sO2 distributions and their temporal response after external changes of the oxygen supply (100% O2 or air breathing and clamping of tumor-supplying artery). The established protocol showed to be suitable for detecting temporal changes in tumor oxygenation as well as differences in oxygenation between tumor sublines. PA results were in accordance with histology for hypoxia, perfusion, and vasculature. The presented protocol for the assessment of pixel-based sO2 distributions provides more detailed information as compared to conventional region-of-interest-based analysis of PAI, especially with respect to the detection of temporal changes and tumor heterogeneity. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  14. Stream-wise distribution of skin-friction drag reduction on a flat plate with bubble injection

    NASA Astrophysics Data System (ADS)

    Qin, Shijie; Chu, Ning; Yao, Yan; Liu, Jingting; Huang, Bin; Wu, Dazhuan

    2017-03-01

    To investigate the stream-wise distribution of skin-friction drag reduction on a flat plate with bubble injection, both experiments and simulations of bubble drag reduction (BDR) have been conducted in this paper. Drag reductions at various flow speeds and air injection rates have been tested in cavitation tunnel experiments. Visualization of bubble flow pattern is implemented synchronously. The computational fluid dynamics (CFD) method, in the framework of Eulerian-Eulerian two fluid modeling, coupled with population balance model (PBM) is used to simulate the bubbly flow along the flat plate. A wide range of bubble sizes considering bubble breakup and coalescence is modeled based on experimental bubble distribution images. Drag and lift forces are fully modeled based on applicable closure models. Both predicted drag reductions and bubble distributions are in reasonable concordance with experimental results. Stream-wise distribution of BDR is revealed based on CFD-PBM numerical results. In particular, four distinct regions with different BDR characteristics are first identified and discussed in this study. Thresholds between regions are extracted and discussed. And it is highly necessary to fully understand the stream-wise distribution of BDR in order to establish a universal scaling law. Moreover, mechanism of stream-wise distribution of BDR is analysed based on the near-wall flow parameters. The local drag reduction is a direct result of near-wall max void fraction. And the near-wall velocity gradient modified by the presence of bubbles is considered as another important factor for bubble drag reduction.

  15. Photoacoustic imaging to assess pixel-based sO2 distributions in experimental prostate tumors

    NASA Astrophysics Data System (ADS)

    Bendinger, Alina L.; Glowa, Christin; Peter, Jörg; Karger, Christian P.

    2018-03-01

    A protocol for photoacoustic imaging (PAI) has been developed to assess pixel-based oxygen saturation (sO2) distributions of experimental tumor models. The protocol was applied to evaluate the dependence of PAI results on measurement settings, reproducibility of PAI, and for the characterization of the oxygenation status of experimental prostate tumor sublines (Dunning R3327-H, -HI, -AT1) implanted subcutaneously in male Copenhagen rats. The three-dimensional (3-D) PA data employing two wavelengths were used to estimate sO2 distributions. If the PA signal was sufficiently strong, the distributions were independent from signal gain, threshold, and positioning of animals. Reproducibility of sO2 distributions with respect to shape and median values was demonstrated over several days. The three tumor sublines were characterized by the shapes of their sO2 distributions and their temporal response after external changes of the oxygen supply (100% O2 or air breathing and clamping of tumor-supplying artery). The established protocol showed to be suitable for detecting temporal changes in tumor oxygenation as well as differences in oxygenation between tumor sublines. PA results were in accordance with histology for hypoxia, perfusion, and vasculature. The presented protocol for the assessment of pixel-based sO2 distributions provides more detailed information as compared to conventional region-of-interest-based analysis of PAI, especially with respect to the detection of temporal changes and tumor heterogeneity.

  16. Distribution System Audits, Leak Detection, and Repair: Kirtland Air Force Base Leak Detection and Repair Program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    Water Best Management Practice #3 Fact Seet: Outlines how a leak detection and repair program helped Kirtland Air Force Base perform distribution system audits, leak detection, and repair to conserve water site-wide.

  17. Epidemic spreading in weighted networks: an edge-based mean-field solution.

    PubMed

    Yang, Zimo; Zhou, Tao

    2012-05-01

    Weight distribution greatly impacts the epidemic spreading taking place on top of networks. This paper presents a study of a susceptible-infected-susceptible model on regular random networks with different kinds of weight distributions. Simulation results show that the more homogeneous weight distribution leads to higher epidemic prevalence, which, unfortunately, could not be captured by the traditional mean-field approximation. This paper gives an edge-based mean-field solution for general weight distribution, which can quantitatively reproduce the simulation results. This method could be applied to characterize the nonequilibrium steady states of dynamical processes on weighted networks.

  18. A spatial scan statistic for survival data based on Weibull distribution.

    PubMed

    Bhatt, Vijaya; Tiwari, Neeraj

    2014-05-20

    The spatial scan statistic has been developed as a geographical cluster detection analysis tool for different types of data sets such as Bernoulli, Poisson, ordinal, normal and exponential. We propose a scan statistic for survival data based on Weibull distribution. It may also be used for other survival distributions, such as exponential, gamma, and log normal. The proposed method is applied on the survival data of tuberculosis patients for the years 2004-2005 in Nainital district of Uttarakhand, India. Simulation studies reveal that the proposed method performs well for different survival distribution functions. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Provably secure time distribution for the electric grid

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith IV, Amos M; Evans, Philip G; Williams, Brian P

    We demonstrate a quantum time distribution (QTD) method that combines the precision of optical timing techniques with the integrity of quantum key distribution (QKD). Critical infrastructure is dependent on microprocessor- and programmable logic-based monitoring and control systems. The distribution of timing information across the electric grid is accomplished by GPS signals which are known to be vulnerable to spoofing. We demonstrate a method for synchronizing remote clocks based on the arrival time of photons in a modifed QKD system. This has the advantage that the signal can be veried by examining the quantum states of the photons similar to QKD.

  20. One Step Quantum Key Distribution Based on EPR Entanglement

    PubMed Central

    Li, Jian; Li, Na; Li, Lei-Lei; Wang, Tao

    2016-01-01

    A novel quantum key distribution protocol is presented, based on entanglement and dense coding and allowing asymptotically secure key distribution. Considering the storage time limit of quantum bits, a grouping quantum key distribution protocol is proposed, which overcomes the vulnerability of first protocol and improves the maneuverability. Moreover, a security analysis is given and a simple type of eavesdropper’s attack would introduce at least an error rate of 46.875%. Compared with the “Ping-pong” protocol involving two steps, the proposed protocol does not need to store the qubit and only involves one step. PMID:27357865

  1. A Distributed Platform for Global-Scale Agent-Based Models of Disease Transmission

    PubMed Central

    Parker, Jon; Epstein, Joshua M.

    2013-01-01

    The Global-Scale Agent Model (GSAM) is presented. The GSAM is a high-performance distributed platform for agent-based epidemic modeling capable of simulating a disease outbreak in a population of several billion agents. It is unprecedented in its scale, its speed, and its use of Java. Solutions to multiple challenges inherent in distributing massive agent-based models are presented. Communication, synchronization, and memory usage are among the topics covered in detail. The memory usage discussion is Java specific. However, the communication and synchronization discussions apply broadly. We provide benchmarks illustrating the GSAM’s speed and scalability. PMID:24465120

  2. Acquisition and Development of a Cognitive Radio Based Wireless Monitoring and Surveillance Testbed for Future Battlefield Communications Research

    DTIC Science & Technology

    2015-03-01

    for Public Release; Distribution Unlimited Final Report: Acquisition and Development of A Cognitive Radio based Wireless Monitoring and Surveillance...journals: Final Report: Acquisition and Development of A Cognitive Radio based Wireless Monitoring and Surveillance Testbed for Future Battlefield...Opeyemi Oduola, Nan Zou, Xiangfang Li, Husheng Li, Lijun Qian. Distributed Spectrum Monitoring and Surveillance using a Cognitive Radio based Testbed

  3. Mars Polar Lander Mission Distributed Operations

    NASA Technical Reports Server (NTRS)

    Norris, J.; Backes, P.; Slostad, J.; Bonitz, R.; Tharp, G.; Tso, K.

    2000-01-01

    The Mars Polar Lander (MPL) mission is the first planetary mission to use Internet-based distributed ground operations where scientists and engineers collaborate in daily mission operations from multiple geographically distributed locations via the Internet.

  4. Review of Vibration-Based Helicopters Health and Usage Monitoring Methods

    DTIC Science & Technology

    2001-04-05

    FM4, NA4, NA4*, NB4 and NB48* (Polyshchuk et al., 1998). The Wigner - Ville distribution ( WVD ) is a joint time-frequency signal analysis. The WVD is one...signal processing methodologies that are of relevance to vibration based damage detection (e.g., Wavelet Transform and Wigner - Ville distribution ) will be...operation cost, reduce maintenance flights, and increase flight safety. Key Words: HUMS; Wavelet Transform; Wigner - Ville distribution ; O&S; Machinery

  5. Breast Cancer Vaccines Based on Dendritic Cells and the Chemokines

    DTIC Science & Technology

    1998-07-01

    Cancer 50: 289, 1992. 13 . Restifo NP, Esquivel F, Dawakami Y , Yewdell JW, Mule JJ, Rosenberg SA, Bennink JR: Identification of human cancers... 13 . REPORT TYPE AND DATES COVERED Annual (l. Jul 97 - 30 Jun 98) 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Breast Cancer Vaccines Based on Dendritic...SUPPLEMENTARY NOTES 19981210 109 - 12a. DISTRIBUTION I AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Approved for public release; distribution unlimited 13

  6. Recommendation System Based On Association Rules For Distributed E-Learning Management Systems

    NASA Astrophysics Data System (ADS)

    Mihai, Gabroveanu

    2015-09-01

    Traditional Learning Management Systems are installed on a single server where learning materials and user data are kept. To increase its performance, the Learning Management System can be installed on multiple servers; learning materials and user data could be distributed across these servers obtaining a Distributed Learning Management System. In this paper is proposed the prototype of a recommendation system based on association rules for Distributed Learning Management System. Information from LMS databases is analyzed using distributed data mining algorithms in order to extract the association rules. Then the extracted rules are used as inference rules to provide personalized recommendations. The quality of provided recommendations is improved because the rules used to make the inferences are more accurate, since these rules aggregate knowledge from all e-Learning systems included in Distributed Learning Management System.

  7. Shallow cumuli ensemble statistics for development of a stochastic parameterization

    NASA Astrophysics Data System (ADS)

    Sakradzija, Mirjana; Seifert, Axel; Heus, Thijs

    2014-05-01

    According to a conventional deterministic approach to the parameterization of moist convection in numerical atmospheric models, a given large scale forcing produces an unique response from the unresolved convective processes. This representation leaves out the small-scale variability of convection, as it is known from the empirical studies of deep and shallow convective cloud ensembles, there is a whole distribution of sub-grid states corresponding to the given large scale forcing. Moreover, this distribution gets broader with the increasing model resolution. This behavior is also consistent with our theoretical understanding of a coarse-grained nonlinear system. We propose an approach to represent the variability of the unresolved shallow-convective states, including the dependence of the sub-grid states distribution spread and shape on the model horizontal resolution. Starting from the Gibbs canonical ensemble theory, Craig and Cohen (2006) developed a theory for the fluctuations in a deep convective ensemble. The micro-states of a deep convective cloud ensemble are characterized by the cloud-base mass flux, which, according to the theory, is exponentially distributed (Boltzmann distribution). Following their work, we study the shallow cumulus ensemble statistics and the distribution of the cloud-base mass flux. We employ a Large-Eddy Simulation model (LES) and a cloud tracking algorithm, followed by a conditional sampling of clouds at the cloud base level, to retrieve the information about the individual cloud life cycles and the cloud ensemble as a whole. In the case of shallow cumulus cloud ensemble, the distribution of micro-states is a generalized exponential distribution. Based on the empirical and theoretical findings, a stochastic model has been developed to simulate the shallow convective cloud ensemble and to test the convective ensemble theory. Stochastic model simulates a compound random process, with the number of convective elements drawn from a Poisson distribution, and cloud properties sub-sampled from a generalized ensemble distribution. We study the role of the different cloud subtypes in a shallow convective ensemble and how the diverse cloud properties and cloud lifetimes affect the system macro-state. To what extent does the cloud-base mass flux distribution deviate from the simple Boltzmann distribution and how does it affect the results from the stochastic model? Is the memory, provided by the finite lifetime of individual clouds, of importance for the ensemble statistics? We also test for the minimal information given as an input to the stochastic model, able to reproduce the ensemble mean statistics and the variability in a convective ensemble. An important property of the resulting distribution of the sub-grid convective states is its scale-adaptivity - the smaller the grid-size, the broader the compound distribution of the sub-grid states.

  8. A Multi Agent-Based Framework for Simulating Household PHEV Distribution and Electric Distribution Network Impact

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cui, Xiaohui; Liu, Cheng; Kim, Hoe Kyoung

    2011-01-01

    The variation of household attributes such as income, travel distance, age, household member, and education for different residential areas may generate different market penetration rates for plug-in hybrid electric vehicle (PHEV). Residential areas with higher PHEV ownership could increase peak electric demand locally and require utilities to upgrade the electric distribution infrastructure even though the capacity of the regional power grid is under-utilized. Estimating the future PHEV ownership distribution at the residential household level can help us understand the impact of PHEV fleet on power line congestion, transformer overload and other unforeseen problems at the local residential distribution network level.more » It can also help utilities manage the timing of recharging demand to maximize load factors and utilization of existing distribution resources. This paper presents a multi agent-based simulation framework for 1) modeling spatial distribution of PHEV ownership at local residential household level, 2) discovering PHEV hot zones where PHEV ownership may quickly increase in the near future, and 3) estimating the impacts of the increasing PHEV ownership on the local electric distribution network with different charging strategies. In this paper, we use Knox County, TN as a case study to show the simulation results of the agent-based model (ABM) framework. However, the framework can be easily applied to other local areas in the US.« less

  9. Probability distributions of bed load particle velocities, accelerations, hop distances, and travel times informed by Jaynes's principle of maximum entropy

    USGS Publications Warehouse

    Furbish, David; Schmeeckle, Mark; Schumer, Rina; Fathel, Siobhan

    2016-01-01

    We describe the most likely forms of the probability distributions of bed load particle velocities, accelerations, hop distances, and travel times, in a manner that formally appeals to inferential statistics while honoring mechanical and kinematic constraints imposed by equilibrium transport conditions. The analysis is based on E. Jaynes's elaboration of the implications of the similarity between the Gibbs entropy in statistical mechanics and the Shannon entropy in information theory. By maximizing the information entropy of a distribution subject to known constraints on its moments, our choice of the form of the distribution is unbiased. The analysis suggests that particle velocities and travel times are exponentially distributed and that particle accelerations follow a Laplace distribution with zero mean. Particle hop distances, viewed alone, ought to be distributed exponentially. However, the covariance between hop distances and travel times precludes this result. Instead, the covariance structure suggests that hop distances follow a Weibull distribution. These distributions are consistent with high-resolution measurements obtained from high-speed imaging of bed load particle motions. The analysis brings us closer to choosing distributions based on our mechanical insight.

  10. Fractional System Identification: An Approach Using Continuous Order-Distributions

    NASA Technical Reports Server (NTRS)

    Hartley, Tom T.; Lorenzo, Carl F.

    1999-01-01

    This paper discusses the identification of fractional- and integer-order systems using the concept of continuous order-distribution. Based on the ability to define systems using continuous order-distributions, it is shown that frequency domain system identification can be performed using least squares techniques after discretizing the order-distribution.

  11. Optimizing Aircraft Utilization for Retrograde Operations

    DTIC Science & Technology

    2012-06-15

    Bardi , E.J. (2011). Transportation: A Supply Chain Perspective (7th edition). Mason, OH: South-Western Cengage Learning. Deboys, J . (2004...Base, Ohio DISTRIBUTION STATEMENT A APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED The views...in Logistics Joel E. Eppley, BS, MA Major, USAF June 2012 DISTRIBUTION STATEMENT A APPROVED FOR PUBLIC RELEASE; DISTRIBUTION

  12. Blockchain for Smart Grid Resilience: Exchanging Distributed Energy at Speed, Scale and Security

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mylrea, Michael E.; Gourisetti, Sri Nikhil Gup

    Blockchain may help solve several complex problems related to integrity and trustworthiness of rapid, distributed, complex energy transactions and data exchanges. In a move towards resilience, blockchain commoditizes trust and enables automated smart contracts to support auditable multiparty transactions based on predefined rules between distributed energy providers and customers. Blockchain based smart contracts also help remove the need to interact with third-parties, facilitating the adoption and monetization of distributed energy transactions and exchanges, both energy flows as well as financial transactions. This may help reduce transactive energy costs and increase the security and sustainability of distributed energy resource (DER) integration,more » helping to remove barriers to a more decentralized and resilient power grid.« less

  13. Performance of distributed multiscale simulations

    PubMed Central

    Borgdorff, J.; Ben Belgacem, M.; Bona-Casas, C.; Fazendeiro, L.; Groen, D.; Hoenen, O.; Mizeranschi, A.; Suter, J. L.; Coster, D.; Coveney, P. V.; Dubitzky, W.; Hoekstra, A. G.; Strand, P.; Chopard, B.

    2014-01-01

    Multiscale simulations model phenomena across natural scales using monolithic or component-based code, running on local or distributed resources. In this work, we investigate the performance of distributed multiscale computing of component-based models, guided by six multiscale applications with different characteristics and from several disciplines. Three modes of distributed multiscale computing are identified: supplementing local dependencies with large-scale resources, load distribution over multiple resources, and load balancing of small- and large-scale resources. We find that the first mode has the apparent benefit of increasing simulation speed, and the second mode can increase simulation speed if local resources are limited. Depending on resource reservation and model coupling topology, the third mode may result in a reduction of resource consumption. PMID:24982258

  14. Estimating Bias Error Distributions

    NASA Technical Reports Server (NTRS)

    Liu, Tian-Shu; Finley, Tom D.

    2001-01-01

    This paper formulates the general methodology for estimating the bias error distribution of a device in a measuring domain from less accurate measurements when a minimal number of standard values (typically two values) are available. A new perspective is that the bias error distribution can be found as a solution of an intrinsic functional equation in a domain. Based on this theory, the scaling- and translation-based methods for determining the bias error distribution arc developed. These methods are virtually applicable to any device as long as the bias error distribution of the device can be sufficiently described by a power series (a polynomial) or a Fourier series in a domain. These methods have been validated through computational simulations and laboratory calibration experiments for a number of different devices.

  15. A physically based catchment partitioning method for hydrological analysis

    NASA Astrophysics Data System (ADS)

    Menduni, Giovanni; Riboni, Vittoria

    2000-07-01

    We propose a partitioning method for the topographic surface, which is particularly suitable for hydrological distributed modelling and shallow-landslide distributed modelling. The model provides variable mesh size and appears to be a natural evolution of contour-based digital terrain models. The proposed method allows the drainage network to be derived from the contour lines. The single channels are calculated via a search for the steepest downslope lines. Then, for each network node, the contributing area is determined by means of a search for both steepest upslope and downslope lines. This leads to the basin being partitioned into physically based finite elements delimited by irregular polygons. In particular, the distributed computation of local geomorphological parameters (i.e. aspect, average slope and elevation, main stream length, concentration time, etc.) can be performed easily for each single element. The contributing area system, together with the information on the distribution of geomorphological parameters provide a useful tool for distributed hydrological modelling and simulation of environmental processes such as erosion, sediment transport and shallow landslides.

  16. Metadata based management and sharing of distributed biomedical data

    PubMed Central

    Vergara-Niedermayr, Cristobal; Liu, Peiya

    2014-01-01

    Biomedical research data sharing is becoming increasingly important for researchers to reuse experiments, pool expertise and validate approaches. However, there are many hurdles for data sharing, including the unwillingness to share, lack of flexible data model for providing context information, difficulty to share syntactically and semantically consistent data across distributed institutions, and high cost to provide tools to share the data. SciPort is a web-based collaborative biomedical data sharing platform to support data sharing across distributed organisations. SciPort provides a generic metadata model to flexibly customise and organise the data. To enable convenient data sharing, SciPort provides a central server based data sharing architecture with a one-click data sharing from a local server. To enable consistency, SciPort provides collaborative distributed schema management across distributed sites. To enable semantic consistency, SciPort provides semantic tagging through controlled vocabularies. SciPort is lightweight and can be easily deployed for building data sharing communities. PMID:24834105

  17. An entropy-based method for determining the flow depth distribution in natural channels

    NASA Astrophysics Data System (ADS)

    Moramarco, Tommaso; Corato, Giovanni; Melone, Florisa; Singh, Vijay P.

    2013-08-01

    A methodology for determining the bathymetry of river cross-sections during floods by the sampling of surface flow velocity and existing low flow hydraulic data is developed . Similar to Chiu (1988) who proposed an entropy-based velocity distribution, the flow depth distribution in a cross-section of a natural channel is derived by entropy maximization. The depth distribution depends on one parameter, whose estimate is straightforward, and on the maximum flow depth. Applying to a velocity data set of five river gage sites, the method modeled the flow area observed during flow measurements and accurately assessed the corresponding discharge by coupling the flow depth distribution and the entropic relation between mean velocity and maximum velocity. The methodology unfolds a new perspective for flow monitoring by remote sensing, considering that the two main quantities on which the methodology is based, i.e., surface flow velocity and flow depth, might be potentially sensed by new sensors operating aboard an aircraft or satellite.

  18. Incorporating Nonstationarity into IDF Curves across CONUS from Station Records and Implications

    NASA Astrophysics Data System (ADS)

    Wang, K.; Lettenmaier, D. P.

    2017-12-01

    Intensity-duration-frequency (IDF) curves are widely used for engineering design of storm-affected structures. Current practice is that IDF-curves are based on observed precipitation extremes fit to a stationary probability distribution (e.g., the extreme value family). However, there is increasing evidence of nonstationarity in station records. We apply the Mann-Kendall trend test to over 1000 stations across the CONUS at a 0.05 significance level, and find that about 30% of stations test have significant nonstationarity for at least one duration (1-, 2-, 3-, 6-, 12-, 24-, and 48-hours). We fit the stations to a GEV distribution with time-varying location and scale parameters using a Bayesian- methodology and compare the fit of stationary versus nonstationary GEV distributions to observed precipitation extremes. Within our fitted nonstationary GEV distributions, we compare distributions with a time-varying location parameter versus distributions with both time-varying location and scale parameters. For distributions with two time-varying parameters, we pay particular attention to instances where location and scale trends have opposing directions. Finally, we use the mathematical framework based on work of Koutsoyiannis to generate IDF curves based on the fitted GEV distributions and discuss the implications that using time-varying parameters may have on simple scaling relationships. We apply the above methods to evaluate how frequency statistics based on a stationary assumption compare to those that incorporate nonstationarity for both short and long term projects. Overall, we find that neglecting nonstationarity can lead to under- or over-estimates (depending on the trend for the given duration and region) of important statistics such as the design storm.

  19. Stability and performance of propulsion control systems with distributed control architectures and failures

    NASA Astrophysics Data System (ADS)

    Belapurkar, Rohit K.

    Future aircraft engine control systems will be based on a distributed architecture, in which, the sensors and actuators will be connected to the Full Authority Digital Engine Control (FADEC) through an engine area network. Distributed engine control architecture will allow the implementation of advanced, active control techniques along with achieving weight reduction, improvement in performance and lower life cycle cost. The performance of a distributed engine control system is predominantly dependent on the performance of the communication network. Due to the serial data transmission policy, network-induced time delays and sampling jitter are introduced between the sensor/actuator nodes and the distributed FADEC. Communication network faults and transient node failures may result in data dropouts, which may not only degrade the control system performance but may even destabilize the engine control system. Three different architectures for a turbine engine control system based on a distributed framework are presented. A partially distributed control system for a turbo-shaft engine is designed based on ARINC 825 communication protocol. Stability conditions and control design methodology are developed for the proposed partially distributed turbo-shaft engine control system to guarantee the desired performance under the presence of network-induced time delay and random data loss due to transient sensor/actuator failures. A fault tolerant control design methodology is proposed to benefit from the availability of an additional system bandwidth and from the broadcast feature of the data network. It is shown that a reconfigurable fault tolerant control design can help to reduce the performance degradation in presence of node failures. A T-700 turbo-shaft engine model is used to validate the proposed control methodology based on both single input and multiple-input multiple-output control design techniques.

  20. Modelling altered revenue function based on varying power consumption distribution and electricity tariff charge using data analytics framework

    NASA Astrophysics Data System (ADS)

    Zainudin, W. N. R. A.; Ramli, N. A.

    2017-09-01

    In 2010, Energy Commission (EC) had introduced Incentive Based Regulation (IBR) to ensure sustainable Malaysian Electricity Supply Industry (MESI), promotes transparent and fair returns, encourage maximum efficiency and maintains policy driven end user tariff. To cater such revolutionary transformation, a sophisticated system to generate policy driven electricity tariff structure is in great need. Hence, this study presents a data analytics framework that generates altered revenue function based on varying power consumption distribution and tariff charge function. For the purpose of this study, the power consumption distribution is being proxy using proportion of household consumption and electricity consumed in KwH and the tariff charge function is being proxy using three-tiered increasing block tariff (IBT). The altered revenue function is useful to give an indication on whether any changes in the power consumption distribution and tariff charges will give positive or negative impact to the economy. The methodology used for this framework begins by defining the revenue to be a function of power consumption distribution and tariff charge function. Then, the proportion of household consumption and tariff charge function is derived within certain interval of electricity power. Any changes in those proportion are conjectured to contribute towards changes in revenue function. Thus, these changes can potentially give an indication on whether the changes in power consumption distribution and tariff charge function are giving positive or negative impact on TNB revenue. Based on the finding of this study, major changes on tariff charge function seems to affect altered revenue function more than power consumption distribution. However, the paper concludes that power consumption distribution and tariff charge function can influence TNB revenue to some great extent.

  1. Calibration of the Diameter Distribution Derived from the Area-based Approach with Individual Tree-based Diameter Estimates Using the Airborne Laser Scanning

    NASA Astrophysics Data System (ADS)

    Xu, Q.; Hou, Z.; Maltamo, M.; Tokola, T.

    2015-12-01

    Diameter distributions of trees are important indicators of current forest stand structure and future dynamics. A new method was proposed in the study to combine the diameter distributions derived from the area-based approach (ABA) and the diameter distribution derived from the individual tree detection (ITD) in order to obtain more accurate forest stand attributes. Since dominant trees can be reliably detected and measured by the Lidar data via the ITD, the focus of the study is to retrieve the suppressed trees (trees that were missed by the ITD) from the ABA. Replacement and histogram matching were respectively employed at the plot level to retrieve the suppressed trees. Cut point was detected from the ITD-derived diameter distribution for each sample plot to distinguish dominant trees from the suppressed trees. The results showed that calibrated diameter distributions were more accurate in terms of error index and the entire growing stock estimates. Compared with the best performer between the ABA and the ITD, calibrated diameter distributions decreased the relative RMSE of the estimated entire growing stock, saw log and pulpwood fractions by 2.81%, 3.05% and 7.73% points respectively. Calibration improved the estimation of pulpwood fraction significantly, resulting in a negligible bias of the estimated entire growing stock.

  2. Distributed Generation Planning using Peer Enhanced Multi-objective Teaching-Learning based Optimization in Distribution Networks

    NASA Astrophysics Data System (ADS)

    Selvam, Kayalvizhi; Vinod Kumar, D. M.; Siripuram, Ramakanth

    2017-04-01

    In this paper, an optimization technique called peer enhanced teaching learning based optimization (PeTLBO) algorithm is used in multi-objective problem domain. The PeTLBO algorithm is parameter less so it reduced the computational burden. The proposed peer enhanced multi-objective based TLBO (PeMOTLBO) algorithm has been utilized to find a set of non-dominated optimal solutions [distributed generation (DG) location and sizing in distribution network]. The objectives considered are: real power loss and the voltage deviation subjected to voltage limits and maximum penetration level of DG in distribution network. Since the DG considered is capable of injecting real and reactive power to the distribution network the power factor is considered as 0.85 lead. The proposed peer enhanced multi-objective optimization technique provides different trade-off solutions in order to find the best compromise solution a fuzzy set theory approach has been used. The effectiveness of this proposed PeMOTLBO is tested on IEEE 33-bus and Indian 85-bus distribution system. The performance is validated with Pareto fronts and two performance metrics (C-metric and S-metric) by comparing with robust multi-objective technique called non-dominated sorting genetic algorithm-II and also with the basic TLBO.

  3. Assessing the availability of LLINs for continuous distribution through routine antenatal care and the Expanded Programme on Immunizations in sub-Saharan Africa.

    PubMed

    Theiss-Nyland, Katherine; Lynch, Michael; Lines, Jo

    2016-05-04

    In addition to mass distribution campaigns, the World Health Organization (WHO) recommends the continuous distribution of long-lasting insecticidal nets (LLINs) to all pregnant women attending antenatal care (ANC) and all infants attending the Expanded Programme on Immunization (EPI) services in countries implementing mosquito nets for malaria control. Countries report LLIN distribution data to the WHO annually. For this analysis, these data were used to assess policy and practice in implementing these recommendations and to compare the numbers of LLINs available through ANC and EPI services with the numbers of women and children attending these services. For each reporting country in sub-Saharan Africa, the presence of a reported policy for LLIN distribution through ANC and EPI was reviewed. Prior to inclusion in the analysis the completeness of data was assessed in terms of the numbers of LLINs distributed through all channels (campaigns, EPI, ANC, other). For each country with adequate data, the numbers of LLINs reportedly distributed by national programmes to ANC was compared to the number of women reportedly attending ANC at least once; the ratio between these two numbers was used as an indicator of LLIN availability at ANC services. The same calculations were repeated for LLINs distributed through EPI to produce the corresponding LLIN availability through this distribution channel. Among 48 malaria-endemic countries in Africa, 33 malaria programmes reported adopting policies of ANC-based continuous distribution of LLINs, and 25 reported adopting policies of EPI-based distribution. Over a 3-year period through 2012, distribution through ANC accounted for 9 % of LLINs distributed, and LLINs distributed through EPI accounted for 4 %. The LLIN availability ratios achieved were 55 % through ANC and 34 % through EPI. For 38 country programmes reporting on LLIN distribution, data to calculate LLIN availability through ANC and EPI was available for 17 and 16, respectively. These continuous LLIN distribution channels appear to be under-utilized, especially EPI-based distribution. However, quality data from more countries are needed for consistent and reliable programme performance monitoring. A greater focus on routine data collection, monitoring and reporting on LLINs distributed through both ANC and EPI can provide insight into both strengths and weaknesses of continuous distribution, and improve the effectiveness of these delivery channels.

  4. Are species photosynthetic characteristics good predictors of seedling post-hurricane demographic patterns and species spatiotemporal distribution in a hurricane impacted wet montane forest?

    NASA Astrophysics Data System (ADS)

    Luke, Denneko; McLaren, Kurt

    2018-05-01

    In situ measurements of leaf level photosynthetic response to light were collected from seedlings of ten tree species from a tropical montane wet forest, the John Crow Mountains, Jamaica. A model-based recursive partitioning ('mob') algorithm was then used to identify species associations based on their fitted photosynthetic response curves. Leaf area dark respiration (RD) and light saturated maximum photosynthetic (Amax) rates were also used as 'mob' partitioning variables, to identify species associations based on seedling demographic patterns (from June 2007 to May 2010) following a hurricane (Aug. 2007) and the spatiotemporal distribution patterns of stems in 2006 and 2012. RD and Amax rates ranged from 1.14 to 2.02 μmol (CO2) m-2s-1 and 2.97-5.87 μmol (CO2) m-2s-1, respectively, placing the ten species in the range of intermediate shade tolerance. Several parsimonious species 'mob' groups were formed based on 1) interspecific differences among species response curves, 2) variations in post-hurricane seedling demographic trends and 3) RD rates and species spatiotemporal distribution patterns at aspects that are more or less exposed to hurricanes. The composition of parsimonious groupings based on photosynthetic curves was not concordant with the groups based on demographic trends but was partially concordant with the RD - species spatiotemporal distribution groups. Our results indicated that the influence of photosynthetic characteristics on demographic traits and species distributions was not straightforward. Rather, there was a complex pattern of interaction between ecophysiological and demographic traits, which determined species successional status, post-hurricane response and ultimately, species distribution at our study site.

  5. Cloud vertical distribution from combined surface and space radar-lidar observations at two Arctic atmospheric observatories

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Yinghui; Shupe, Matthew D.; Wang, Zhien

    Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identifymore » the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25-40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid-containing cloud fraction at Eureka than at Barrow; the differences can be attributed to the generally colder and drier conditions at Eureka relative to Barrow.« less

  6. Cloud vertical distribution from combined surface and space radar-lidar observations at two Arctic atmospheric observatories

    DOE PAGES

    Liu, Yinghui; Shupe, Matthew D.; Wang, Zhien; ...

    2017-05-16

    Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identifymore » the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25-40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid-containing cloud fraction at Eureka than at Barrow; the differences can be attributed to the generally colder and drier conditions at Eureka relative to Barrow.« less

  7. PLUME-MoM 1.0: a new 1-D model of volcanic plumes based on the method of moments

    NASA Astrophysics Data System (ADS)

    de'Michieli Vitturi, M.; Neri, A.; Barsotti, S.

    2015-05-01

    In this paper a new mathematical model for volcanic plumes, named PlumeMoM, is presented. The model describes the steady-state 1-D dynamics of the plume in a 3-D coordinate system, accounting for continuous variability in particle distribution of the pyroclastic mixture ejected at the vent. Volcanic plumes are composed of pyroclastic particles of many different sizes ranging from a few microns up to several centimeters and more. Proper description of such a multiparticle nature is crucial when quantifying changes in grain-size distribution along the plume and, therefore, for better characterization of source conditions of ash dispersal models. The new model is based on the method of moments, which allows description of the pyroclastic mixture dynamics not only in the spatial domain but also in the space of properties of the continuous size-distribution of the particles. This is achieved by formulation of fundamental transport equations for the multiparticle mixture with respect to the different moments of the grain-size distribution. Different formulations, in terms of the distribution of the particle number, as well as of the mass distribution expressed in terms of the Krumbein log scale, are also derived. Comparison between the new moments-based formulation and the classical approach, based on the discretization of the mixture in N discrete phases, shows that the new model allows the same results to be obtained with a significantly lower computational cost (particularly when a large number of discrete phases is adopted). Application of the new model, coupled with uncertainty quantification and global sensitivity analyses, enables investigation of the response of four key output variables (mean and standard deviation (SD) of the grain-size distribution at the top of the plume, plume height and amount of mass lost by the plume during the ascent) to changes in the main input parameters (mean and SD) characterizing the pyroclastic mixture at the base of the plume. Results show that, for the range of parameters investigated, the grain-size distribution at the top of the plume is remarkably similar to that at the base and that the plume height is only weakly affected by the parameters of the grain distribution.

  8. Use of Anecdotal Occurrence Data in Species Distribution Models: An Example Based on the White-Nosed Coati (Nasua narica) in the American Southwest

    PubMed Central

    Frey, Jennifer K.; Lewis, Jeremy C.; Guy, Rachel K.; Stuart, James N.

    2013-01-01

    Simple Summary We evaluated the influence of occurrence records with different reliability on predicted distribution of a unique, rare mammal in the American Southwest, the white-nosed coati (Nasua narica). We concluded that occurrence datasets that include anecdotal records can be used to infer species distributions, providing such data are used only for easily-identifiable species and based on robust modeling methods such as maximum entropy. Use of a reliability rating system is critical for using anecdotal data. Abstract Species distributions are usually inferred from occurrence records. However, these records are prone to errors in spatial precision and reliability. Although influence of spatial errors has been fairly well studied, there is little information on impacts of poor reliability. Reliability of an occurrence record can be influenced by characteristics of the species, conditions during the observation, and observer’s knowledge. Some studies have advocated use of anecdotal data, while others have advocated more stringent evidentiary standards such as only accepting records verified by physical evidence, at least for rare or elusive species. Our goal was to evaluate the influence of occurrence records with different reliability on species distribution models (SDMs) of a unique mammal, the white-nosed coati (Nasua narica) in the American Southwest. We compared SDMs developed using maximum entropy analysis of combined bioclimatic and biophysical variables and based on seven subsets of occurrence records that varied in reliability and spatial precision. We found that the predicted distribution of the coati based on datasets that included anecdotal occurrence records were similar to those based on datasets that only included physical evidence. Coati distribution in the American Southwest was predicted to occur in southwestern New Mexico and southeastern Arizona and was defined primarily by evenness of climate and Madrean woodland and chaparral land-cover types. Coati distribution patterns in this region suggest a good model for understanding the biogeographic structure of range margins. We concluded that occurrence datasets that include anecdotal records can be used to infer species distributions, providing such data are used only for easily-identifiable species and based on robust modeling methods such as maximum entropy. Use of a reliability rating system is critical for using anecdotal data. PMID:26487405

  9. Distribution of Base Pair Alternations in a Periodic DNA Chain: Application of Pólya Counting to a Physical System

    NASA Astrophysics Data System (ADS)

    Hillebrand, Malcolm; Paterson-Jones, Guy; Kalosakas, George; Skokos, Charalampos

    2018-03-01

    In modeling DNA chains, the number of alternations between Adenine-Thymine (AT) and Guanine-Cytosine (GC) base pairs can be considered as a measure of the heterogeneity of the chain, which in turn could affect its dynamics. A probability distribution function of the number of these alternations is derived for circular or periodic DNA. Since there are several symmetries to account for in the periodic chain, necklace counting methods are used. In particular, Polya's Enumeration Theorem is extended for the case of a group action that preserves partitioned necklaces. This, along with the treatment of generating functions as formal power series, allows for the direct calculation of the number of possible necklaces with a given number of AT base pairs, GC base pairs and alternations. The theoretically obtained probability distribution functions of the number of alternations are accurately reproduced by Monte Carlo simulations and fitted by Gaussians. The effect of the number of base pairs on the characteristics of these distributions is also discussed, as well as the effect of the ratios of the numbers of AT and GC base pairs.

  10. Efficient Agent-Based Cluster Ensembles

    NASA Technical Reports Server (NTRS)

    Agogino, Adrian; Tumer, Kagan

    2006-01-01

    Numerous domains ranging from distributed data acquisition to knowledge reuse need to solve the cluster ensemble problem of combining multiple clusterings into a single unified clustering. Unfortunately current non-agent-based cluster combining methods do not work in a distributed environment, are not robust to corrupted clusterings and require centralized access to all original clusterings. Overcoming these issues will allow cluster ensembles to be used in fundamentally distributed and failure-prone domains such as data acquisition from satellite constellations, in addition to domains demanding confidentiality such as combining clusterings of user profiles. This paper proposes an efficient, distributed, agent-based clustering ensemble method that addresses these issues. In this approach each agent is assigned a small subset of the data and votes on which final cluster its data points should belong to. The final clustering is then evaluated by a global utility, computed in a distributed way. This clustering is also evaluated using an agent-specific utility that is shown to be easier for the agents to maximize. Results show that agents using the agent-specific utility can achieve better performance than traditional non-agent based methods and are effective even when up to 50% of the agents fail.

  11. Stratospheric aerosol particle size distribution based on multi-color polarization measurements of the twilight sky

    NASA Astrophysics Data System (ADS)

    Ugolnikov, Oleg S.; Maslov, Igor A.

    2018-03-01

    Polarization measurements of the twilight background with Wide-Angle Polarization Camera (WAPC) are used to detect the depolarization effect caused by stratospheric aerosol near the altitude of 20 km. Based on a number of observations in central Russia in spring and summer 2016, we found the parameters of lognormal size distribution of aerosol particles. This confirmed the previously published results of the colorimetric method as applied to the same twilights. The mean particle radius (about 0.1 micrometers) and size distribution are also in agreement with the recent data of in situ and space-based remote sensing of stratospheric aerosol. Methods considered here provide two independent techniques of the stratospheric aerosol study based on the twilight sky analysis.

  12. Research on logistics scheduling based on PSO

    NASA Astrophysics Data System (ADS)

    Bao, Huifang; Zhou, Linli; Liu, Lei

    2017-08-01

    With the rapid development of e-commerce based on the network, the logistics distribution support of e-commerce is becoming more and more obvious. The optimization of vehicle distribution routing can improve the economic benefit and realize the scientific of logistics [1]. Therefore, the study of logistics distribution vehicle routing optimization problem is not only of great theoretical significance, but also of considerable value of value. Particle swarm optimization algorithm is a kind of evolutionary algorithm, which is based on the random solution and the optimal solution by iteration, and the quality of the solution is evaluated through fitness. In order to obtain a more ideal logistics scheduling scheme, this paper proposes a logistics model based on particle swarm optimization algorithm.

  13. Distributed Optimization Design of Continuous-Time Multiagent Systems With Unknown-Frequency Disturbances.

    PubMed

    Wang, Xinghu; Hong, Yiguang; Yi, Peng; Ji, Haibo; Kang, Yu

    2017-05-24

    In this paper, a distributed optimization problem is studied for continuous-time multiagent systems with unknown-frequency disturbances. A distributed gradient-based control is proposed for the agents to achieve the optimal consensus with estimating unknown frequencies and rejecting the bounded disturbance in the semi-global sense. Based on convex optimization analysis and adaptive internal model approach, the exact optimization solution can be obtained for the multiagent system disturbed by exogenous disturbances with uncertain parameters.

  14. Estimation of synthetic flood design hydrographs using a distributed rainfall-runoff model coupled with a copula-based single storm rainfall generator

    NASA Astrophysics Data System (ADS)

    Candela, A.; Brigandì, G.; Aronica, G. T.

    2014-07-01

    In this paper a procedure to derive synthetic flood design hydrographs (SFDH) using a bivariate representation of rainfall forcing (rainfall duration and intensity) via copulas, which describes and models the correlation between two variables independently of the marginal laws involved, coupled with a distributed rainfall-runoff model, is presented. Rainfall-runoff modelling (R-R modelling) for estimating the hydrological response at the outlet of a catchment was performed by using a conceptual fully distributed procedure based on the Soil Conservation Service - Curve Number method as an excess rainfall model and on a distributed unit hydrograph with climatic dependencies for the flow routing. Travel time computation, based on the distributed unit hydrograph definition, was performed by implementing a procedure based on flow paths, determined from a digital elevation model (DEM) and roughness parameters obtained from distributed geographical information. In order to estimate the primary return period of the SFDH, which provides the probability of occurrence of a hydrograph flood, peaks and flow volumes obtained through R-R modelling were treated statistically using copulas. Finally, the shapes of hydrographs have been generated on the basis of historically significant flood events, via cluster analysis. An application of the procedure described above has been carried out and results presented for the case study of the Imera catchment in Sicily, Italy.

  15. General Metropolis-Hastings jump diffusions for automatic target recognition in infrared scenes

    NASA Astrophysics Data System (ADS)

    Lanterman, Aaron D.; Miller, Michael I.; Snyder, Donald L.

    1997-04-01

    To locate and recognize ground-based targets in forward- looking IR (FLIR) images, 3D faceted models with associated pose parameters are formulated to accommodate the variability found in FLIR imagery. Taking a Bayesian approach, scenes are simulated from the emissive characteristics of the CAD models and compared with the collected data by a likelihood function based on sensor statistics. This likelihood is combined with a prior distribution defined over the set of possible scenes to form a posterior distribution. To accommodate scenes with variable numbers of targets, the posterior distribution is defined over parameter vectors of varying dimension. An inference algorithm based on Metropolis-Hastings jump- diffusion processes empirically samples from the posterior distribution, generating configurations of templates and transformations that match the collected sensor data with high probability. The jumps accommodate the addition and deletion of targets and the estimation of target identities; diffusions refine the hypotheses by drifting along the gradient of the posterior distribution with respect to the orientation and position parameters. Previous results on jumps strategies analogous to the Metropolis acceptance/rejection algorithm, with proposals drawn from the prior and accepted based on the likelihood, are extended to encompass general Metropolis-Hastings proposal densities. In particular, the algorithm proposes moves by drawing from the posterior distribution over computationally tractible subsets of the parameter space. The algorithm is illustrated by an implementation on a Silicon Graphics Onyx/Reality Engine.

  16. Regional model-based computerized ionospheric tomography using GPS measurements: IONOLAB-CIT

    NASA Astrophysics Data System (ADS)

    Tuna, Hakan; Arikan, Orhan; Arikan, Feza

    2015-10-01

    Three-dimensional imaging of the electron density distribution in the ionosphere is a crucial task for investigating the ionospheric effects. Dual-frequency Global Positioning System (GPS) satellite signals can be used to estimate the slant total electron content (STEC) along the propagation path between a GPS satellite and ground-based receiver station. However, the estimated GPS-STEC is very sparse and highly nonuniformly distributed for obtaining reliable 3-D electron density distributions derived from the measurements alone. Standard tomographic reconstruction techniques are not accurate or reliable enough to represent the full complexity of variable ionosphere. On the other hand, model-based electron density distributions are produced according to the general trends of ionosphere, and these distributions do not agree with measurements, especially for geomagnetically active hours. In this study, a regional 3-D electron density distribution reconstruction method, namely, IONOLAB-CIT, is proposed to assimilate GPS-STEC into physical ionospheric models. The proposed method is based on an iterative optimization framework that tracks the deviations from the ionospheric model in terms of F2 layer critical frequency and maximum ionization height resulting from the comparison of International Reference Ionosphere extended to Plasmasphere (IRI-Plas) model-generated STEC and GPS-STEC. The suggested tomography algorithm is applied successfully for the reconstruction of electron density profiles over Turkey, during quiet and disturbed hours of ionosphere using Turkish National Permanent GPS Network.

  17. Virginia Curriculum Management Guide.

    ERIC Educational Resources Information Center

    Virginia Commonwealth Univ., Richmond. School of Education.

    This document is a competency-based curriculum guide for use in marketing/distributive education programs in Virginia high schools. Following a section on the Virginia standards for competency-based education, the guide provides descriptions for all courses in the Virginia curriculum in the marketing/distributive education program. For each…

  18. A knowledge base architecture for distributed knowledge agents

    NASA Technical Reports Server (NTRS)

    Riedesel, Joel; Walls, Bryan

    1990-01-01

    A tuple space based object oriented model for knowledge base representation and interpretation is presented. An architecture for managing distributed knowledge agents is then implemented within the model. The general model is based upon a database implementation of a tuple space. Objects are then defined as an additional layer upon the database. The tuple space may or may not be distributed depending upon the database implementation. A language for representing knowledge and inference strategy is defined whose implementation takes advantage of the tuple space. The general model may then be instantiated in many different forms, each of which may be a distinct knowledge agent. Knowledge agents may communicate using tuple space mechanisms as in the LINDA model as well as using more well known message passing mechanisms. An implementation of the model is presented describing strategies used to keep inference tractable without giving up expressivity. An example applied to a power management and distribution network for Space Station Freedom is given.

  19. Federated software defined network operations for LHC experiments

    NASA Astrophysics Data System (ADS)

    Kim, Dongkyun; Byeon, Okhwan; Cho, Kihyeon

    2013-09-01

    The most well-known high-energy physics collaboration, the Large Hadron Collider (LHC), which is based on e-Science, has been facing several challenges presented by its extraordinary instruments in terms of the generation, distribution, and analysis of large amounts of scientific data. Currently, data distribution issues are being resolved by adopting an advanced Internet technology called software defined networking (SDN). Stability of the SDN operations and management is demanded to keep the federated LHC data distribution networks reliable. Therefore, in this paper, an SDN operation architecture based on the distributed virtual network operations center (DvNOC) is proposed to enable LHC researchers to assume full control of their own global end-to-end data dissemination. This may achieve an enhanced data delivery performance based on data traffic offloading with delay variation. The evaluation results indicate that the overall end-to-end data delivery performance can be improved over multi-domain SDN environments based on the proposed federated SDN/DvNOC operation framework.

  20. Game theoretic sensor management for target tracking

    NASA Astrophysics Data System (ADS)

    Shen, Dan; Chen, Genshe; Blasch, Erik; Pham, Khanh; Douville, Philip; Yang, Chun; Kadar, Ivan

    2010-04-01

    This paper develops and evaluates a game-theoretic approach to distributed sensor-network management for target tracking via sensor-based negotiation. We present a distributed sensor-based negotiation game model for sensor management for multi-sensor multi-target tacking situations. In our negotiation framework, each negotiation agent represents a sensor and each sensor maximizes their utility using a game approach. The greediness of each sensor is limited by the fact that the sensor-to-target assignment efficiency will decrease if too many sensor resources are assigned to a same target. It is similar to the market concept in real world, such as agreements between buyers and sellers in an auction market. Sensors are willing to switch targets so that they can obtain their highest utility and the most efficient way of applying their resources. Our sub-game perfect equilibrium-based negotiation strategies dynamically and distributedly assign sensors to targets. Numerical simulations are performed to demonstrate our sensor-based negotiation approach for distributed sensor management.

  1. Enhanced interfaces for web-based enterprise-wide image distribution.

    PubMed

    Jost, R Gilbert; Blaine, G James; Fritz, Kevin; Blume, Hartwig; Sadhra, Sarbjit

    2002-01-01

    Modern Web browsers support image distribution with two shortcomings: (1) image grayscale presentation at client workstations is often sub-optimal and generally inconsistent with the presentation state on diagnostic workstations and (2) an Electronic Patient Record (EPR) application usually cannot directly access images with an integrated viewer. We have modified our EPR and our Web-based image-distribution system to allow access to images from within the EPR. In addition, at the client workstation, a grayscale transformation is performed that consists of two components: a client-display-specific component based on the characteristic display function of the class of display system, and a modality-specific transformation that is downloaded with every image. The described techniques have been implemented in our institution and currently support enterprise-wide clinical image distribution. The effectiveness of the techniques is reviewed.

  2. Satellite-to-Ground Entanglement-Based Quantum Key Distribution.

    PubMed

    Yin, Juan; Cao, Yuan; Li, Yu-Huai; Ren, Ji-Gang; Liao, Sheng-Kai; Zhang, Liang; Cai, Wen-Qi; Liu, Wei-Yue; Li, Bo; Dai, Hui; Li, Ming; Huang, Yong-Mei; Deng, Lei; Li, Li; Zhang, Qiang; Liu, Nai-Le; Chen, Yu-Ao; Lu, Chao-Yang; Shu, Rong; Peng, Cheng-Zhi; Wang, Jian-Yu; Pan, Jian-Wei

    2017-11-17

    We report on entanglement-based quantum key distribution between a low-Earth-orbit satellite equipped with a space borne entangled-photon source and a ground observatory. One of the entangled photons is measured locally at the satellite, and the other one is sent via a down link to the receiver in the Delingha ground station. The link attenuation is measured to vary from 29 dB at 530 km to 36 dB at 1000 km. We observe that the two-photon entanglement survives after being distributed between the satellite and the ground, with a measured state fidelity of ≥0.86. We then perform the entanglement-based quantum key distribution protocol and obtain an average final key rate of 3.5  bits/s at the distance range of 530-1000 km.

  3. On measures of association among genetic variables

    PubMed Central

    Gianola, Daniel; Manfredi, Eduardo; Simianer, Henner

    2012-01-01

    Summary Systems involving many variables are important in population and quantitative genetics, for example, in multi-trait prediction of breeding values and in exploration of multi-locus associations. We studied departures of the joint distribution of sets of genetic variables from independence. New measures of association based on notions of statistical distance between distributions are presented. These are more general than correlations, which are pairwise measures, and lack a clear interpretation beyond the bivariate normal distribution. Our measures are based on logarithmic (Kullback-Leibler) and on relative ‘distances’ between distributions. Indexes of association are developed and illustrated for quantitative genetics settings in which the joint distribution of the variables is either multivariate normal or multivariate-t, and we show how the indexes can be used to study linkage disequilibrium in a two-locus system with multiple alleles and present applications to systems of correlated beta distributions. Two multivariate beta and multivariate beta-binomial processes are examined, and new distributions are introduced: the GMS-Sarmanov multivariate beta and its beta-binomial counterpart. PMID:22742500

  4. Online monitoring of seismic damage in water distribution systems

    NASA Astrophysics Data System (ADS)

    Liang, Jianwen; Xiao, Di; Zhao, Xinhua; Zhang, Hongwei

    2004-07-01

    It is shown that water distribution systems can be damaged by earthquakes, and the seismic damages cannot easily be located, especially immediately after the events. Earthquake experiences show that accurate and quick location of seismic damage is critical to emergency response of water distribution systems. This paper develops a methodology to locate seismic damage -- multiple breaks in a water distribution system by monitoring water pressure online at limited positions in the water distribution system. For the purpose of online monitoring, supervisory control and data acquisition (SCADA) technology can well be used. A neural network-based inverse analysis method is constructed for locating the seismic damage based on the variation of water pressure. The neural network is trained by using analytically simulated data from the water distribution system, and validated by using a set of data that have never been used in the training. It is found that the methodology provides an effective and practical way in which seismic damage in a water distribution system can be accurately and quickly located.

  5. Spatially distributed modal signals of free shallow membrane shell structronic system

    NASA Astrophysics Data System (ADS)

    Yue, H. H.; Deng, Z. Q.; Tzou, H. S.

    2008-11-01

    Based on the smart material and structronics technology, distributed sensor and control of shell structures have been rapidly developed for the last 20 years. This emerging technology has been utilized in aerospace, telecommunication, micro-electromechanical systems and other engineering applications. However, distributed monitoring technique and its resulting global spatially distributed sensing signals of shallow paraboloidal membrane shells are not clearly understood. In this paper, modeling of free flexible paraboloidal shell with spatially distributed sensor, micro-sensing signal characteristics, and location of distributed piezoelectric sensor patches are investigated based on a new set of assumed mode shape functions. Parametric analysis indicates that the signal generation depends on modal membrane strains in the meridional and circumferential directions in which the latter is more significant than the former, when all bending strains vanish in membrane shells. This study provides a modeling and analysis technique for distributed sensors laminated on lightweight paraboloidal flexible structures and identifies critical components and regions that generate significant signals.

  6. Wealth distribution, Pareto law, and stretched exponential decay of money: Computer simulations analysis of agent-based models

    NASA Astrophysics Data System (ADS)

    Aydiner, Ekrem; Cherstvy, Andrey G.; Metzler, Ralf

    2018-01-01

    We study by Monte Carlo simulations a kinetic exchange trading model for both fixed and distributed saving propensities of the agents and rationalize the person and wealth distributions. We show that the newly introduced wealth distribution - that may be more amenable in certain situations - features a different power-law exponent, particularly for distributed saving propensities of the agents. For open agent-based systems, we analyze the person and wealth distributions and find that the presence of trap agents alters their amplitude, leaving however the scaling exponents nearly unaffected. For an open system, we show that the total wealth - for different trap agent densities and saving propensities of the agents - decreases in time according to the classical Kohlrausch-Williams-Watts stretched exponential law. Interestingly, this decay does not depend on the trap agent density, but rather on saving propensities. The system relaxation for fixed and distributed saving schemes are found to be different.

  7. Technical and Economic Assessment of the Implementation of Measures for Reducing Energy Losses in Distribution Systems

    NASA Astrophysics Data System (ADS)

    Aguila, Alexander; Wilson, Jorge

    2017-07-01

    This paper develops a methodology to assess a group of measures of electrical improvements in distribution systems, starting from the complementation of technical and economic criteria. In order to solve the problem of energy losses in distribution systems, technical and economic analysis was performed based on a mathematical model to establish a direct relationship between the energy saved by way of minimized losses and the costs of implementing the proposed measures. This paper aims at analysing the feasibility of reducing energy losses in distribution systems, by changing existing network conductors by larger crosssection conductors and distribution voltage change at higher levels. The impact of this methodology provides a highly efficient mathematical tool for analysing the feasibility of implementing improvement projects based on their costs which is a very useful tool for the distribution companies that will serve as a starting point to the analysis for this type of projects in distribution systems.

  8. Crack problem in superconducting cylinder with exponential distribution of critical-current density

    NASA Astrophysics Data System (ADS)

    Zhao, Yufeng; Xu, Chi; Shi, Liang

    2018-04-01

    The general problem of a center crack in a long cylindrical superconductor with inhomogeneous critical-current distribution is studied based on the extended Bean model for zero-field cooling (ZFC) and field cooling (FC) magnetization processes, in which the inhomogeneous parameter η is introduced for characterizing the critical-current density distribution in inhomogeneous superconductor. The effect of the inhomogeneous parameter η on both the magnetic field distribution and the variations of the normalized stress intensity factors is also obtained based on the plane strain approach and J-integral theory. The numerical results indicate that the exponential distribution of critical-current density will lead a larger trapped field inside the inhomogeneous superconductor and cause the center of the cylinder to fracture more easily. In addition, it is worth pointing out that the nonlinear field distribution is unique to the Bean model by comparing the curve shapes of the magnetization loop with homogeneous and inhomogeneous critical-current distribution.

  9. Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks.

    PubMed

    Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F; Schnabel, Roman

    2015-10-30

    Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein-Podolsky-Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.

  10. Temperature measurement and damage detection in concrete beams exposed to fire using PPP-BOTDA based fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Bao, Yi; Hoehler, Matthew S.; Smith, Christopher M.; Bundy, Matthew; Chen, Genda

    2017-10-01

    In this study, Brillouin scattering-based distributed fiber optic sensor is implemented to measure temperature distributions and detect cracks in concrete structures subjected to fire for the first time. A telecommunication-grade optical fiber is characterized as a high temperature sensor with pulse pre-pump Brillouin optical time domain analysis (PPP-BODTA), and implemented to measure spatially-distributed temperatures in reinforced concrete beams in fire. Four beams were tested to failure in a natural gas fueled compartment fire, each instrumented with one fused silica, single-mode optical fiber as a distributed sensor and four thermocouples. Prior to concrete cracking, the distributed temperature was validated at locations of the thermocouples by a relative difference of less than 9%. The cracks in concrete can be identified as sharp peaks in the temperature distribution since the cracks are locally filled with hot air. Concrete cracking did not affect the sensitivity of the distributed sensor but concrete spalling broke the optical fiber loop required for PPP-BOTDA measurements.

  11. Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks

    PubMed Central

    Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F.; Schnabel, Roman

    2015-01-01

    Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components. PMID:26514280

  12. Non-contact assessment of melanin distribution via multispectral temporal illumination coding

    NASA Astrophysics Data System (ADS)

    Amelard, Robert; Scharfenberger, Christian; Wong, Alexander; Clausi, David A.

    2015-03-01

    Melanin is a pigment that is highly absorptive in the UV and visible electromagnetic spectra. It is responsible for perceived skin tone, and protects against harmful UV effects. Abnormal melanin distribution is often an indicator for melanoma. We propose a novel approach for non-contact melanin distribution via multispectral temporal illumination coding to estimate the two-dimensional melanin distribution based on its absorptive characteristics. In the proposed system, a novel multispectral, cross-polarized, temporally-coded illumination sequence is synchronized with a camera to measure reflectance under both multispectral and ambient illumination. This allows us to eliminate the ambient illumination contribution from the acquired reflectance measurements, and also to determine the melanin distribution in an observed region based on the spectral properties of melanin using the Beer-Lambert law. Using this information, melanin distribution maps can be generated for objective, quantitative assessment of skin type of individuals. We show that the melanin distribution map correctly identifies areas with high melanin densities (e.g., nevi).

  13. MO-FG-204-08: Optimization-Based Image Reconstruction From Unevenly Distributed Sparse Projection Views

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xie, Huiqiao; Yang, Yi; Tang, Xiangyang

    2015-06-15

    Purpose: Optimization-based reconstruction has been proposed and investigated for reconstructing CT images from sparse views, as such the radiation dose can be substantially reduced while maintaining acceptable image quality. The investigation has so far focused on reconstruction from evenly distributed sparse views. Recognizing the clinical situations wherein only unevenly sparse views are available, e.g., image guided radiation therapy, CT perfusion and multi-cycle cardiovascular imaging, we investigate the performance of optimization-based image reconstruction from unevenly sparse projection views in this work. Methods: The investigation is carried out using the FORBILD and an anthropomorphic head phantoms. In the study, 82 views, whichmore » are evenly sorted out from a full (360°) axial CT scan consisting of 984 views, form sub-scan I. Another 82 views are sorted out in a similar manner to form sub-scan II. As such, a CT scan with sparse (164) views at 1:6 ratio are formed. By shifting the two sub-scans relatively in view angulation, a CT scan with unevenly distributed sparse (164) views at 1:6 ratio are formed. An optimization-based method is implemented to reconstruct images from the unevenly distributed views. By taking the FBP reconstruction from the full scan (984 views) as the reference, the root mean square (RMS) between the reference and the optimization-based reconstruction is used to evaluate the performance quantitatively. Results: In visual inspection, the optimization-based method outperforms the FBP substantially in the reconstruction from unevenly distributed, which are quantitatively verified by the RMS gauged globally and in ROIs in both the FORBILD and anthropomorphic head phantoms. The RMS increases with increasing severity in the uneven angular distribution, especially in the case of anthropomorphic head phantom. Conclusion: The optimization-based image reconstruction can save radiation dose up to 12-fold while providing acceptable image quality for advanced clinical applications wherein only unevenly distributed sparse views are available. Research Grants: W81XWH-12-1-0138 (DoD), Sinovision Technologies.« less

  14. Design of Distributed Engine Control Systems for Stability Under Communication Packet Dropouts

    DTIC Science & Technology

    2009-08-01

    remarks. II. Distributed Engine Control Systems A. FADEC based on Distributed Engine Control Architecture (DEC) In Distributed Engine...Control, the functions of Full Authority Digital Engine Control ( FADEC ) are distributed at the component level. Each sensor/actuator is to be replaced...diagnostics and health management functionality. Dual channel digital serial communication network is used to connect these smart modules with FADEC . Fig

  15. Sampling--how big a sample?

    PubMed

    Aitken, C G

    1999-07-01

    It is thought that, in a consignment of discrete units, a certain proportion of the units contain illegal material. A sample of the consignment is to be inspected. Various methods for the determination of the sample size are compared. The consignment will be considered as a random sample from some super-population of units, a certain proportion of which contain drugs. For large consignments, a probability distribution, known as the beta distribution, for the proportion of the consignment which contains illegal material is obtained. This distribution is based on prior beliefs about the proportion. Under certain specific conditions the beta distribution gives the same numerical results as an approach based on the binomial distribution. The binomial distribution provides a probability for the number of units in a sample which contain illegal material, conditional on knowing the proportion of the consignment which contains illegal material. This is in contrast to the beta distribution which provides probabilities for the proportion of a consignment which contains illegal material, conditional on knowing the number of units in the sample which contain illegal material. The interpretation when the beta distribution is used is much more intuitively satisfactory. It is also much more flexible in its ability to cater for prior beliefs which may vary given the different circumstances of different crimes. For small consignments, a distribution, known as the beta-binomial distribution, for the number of units in the consignment which are found to contain illegal material, is obtained, based on prior beliefs about the number of units in the consignment which are thought to contain illegal material. As with the beta and binomial distributions for large samples, it is shown that, in certain specific conditions, the beta-binomial and hypergeometric distributions give the same numerical results. However, the beta-binomial distribution, as with the beta distribution, has a more intuitively satisfactory interpretation and greater flexibility. The beta and the beta-binomial distributions provide methods for the determination of the minimum sample size to be taken from a consignment in order to satisfy a certain criterion. The criterion requires the specification of a proportion and a probability.

  16. Online location of a break in water distribution systems

    NASA Astrophysics Data System (ADS)

    Liang, Jianwen; Xiao, Di; Zhao, Xinhua; Zhang, Hongwei

    2003-08-01

    Breaks often occur to urban water distribution systems under severely cold weather, or due to corrosion of pipes, deformation of ground, etc., and the breaks cannot easily be located, especially immediately after the events. This paper develops a methodology to locate a break in a water distribution system by monitoring water pressure online at some nodes in the water distribution system. For the purpose of online monitoring, supervisory control and data acquisition (SCADA) technology can well be used. A neural network-based inverse analysis method is constructed for locating the break based on the variation of water pressure. The neural network is trained by using analytically simulated data from the water distribution system, and validated by using a set of data that have never been used in the training. It is found that the methodology provides a quick, effective, and practical way in which a break in a water distribution system can be located.

  17. A dynamic re-partitioning strategy based on the distribution of key in Spark

    NASA Astrophysics Data System (ADS)

    Zhang, Tianyu; Lian, Xin

    2018-05-01

    Spark is a memory-based distributed data processing framework, has the ability of processing massive data and becomes a focus in Big Data. But the performance of Spark Shuffle depends on the distribution of data. The naive Hash partition function of Spark can not guarantee load balancing when data is skewed. The time of job is affected by the node which has more data to process. In order to handle this problem, dynamic sampling is used. In the process of task execution, histogram is used to count the key frequency distribution of each node, and then generate the global key frequency distribution. After analyzing the distribution of key, load balance of data partition is achieved. Results show that the Dynamic Re-Partitioning function is better than the default Hash partition, Fine Partition and the Balanced-Schedule strategy, it can reduce the execution time of the task and improve the efficiency of the whole cluster.

  18. Temperature Measurement and Damage Detection in Concrete Beams Exposed to Fire Using PPP-BOTDA Based Fiber Optic Sensors.

    PubMed

    Bao, Yi; Hoehler, Matthew S; Smith, Christopher M; Bundy, Matthew; Chen, Genda

    2017-10-01

    In this study, distributed fiber optic sensors based on pulse pre-pump Brillouin optical time domain analysis (PPP-BODTA) are characterized and deployed to measure spatially-distributed temperatures in reinforced concrete specimens exposed to fire. Four beams were tested to failure in a natural gas fueled compartment fire, each instrumented with one fused silica, single-mode optical fiber as a distributed sensor and four thermocouples. Prior to concrete cracking, the distributed temperature was validated at locations of the thermocouples by a relative difference of less than 9 %. The cracks in concrete can be identified as sharp peaks in the temperature distribution since the cracks are locally filled with hot air. Concrete cracking did not affect the sensitivity of the distributed sensor but concrete spalling broke the optical fiber loop required for PPP-BOTDA measurements.

  19. Field size, length, and width distributions based on LACIE ground truth data. [large area crop inventory experiment

    NASA Technical Reports Server (NTRS)

    Pitts, D. E.; Badhwar, G.

    1980-01-01

    The development of agricultural remote sensing systems requires knowledge of agricultural field size distributions so that the sensors, sampling frames, image interpretation schemes, registration systems, and classification systems can be properly designed. Malila et al. (1976) studied the field size distribution for wheat and all other crops in two Kansas LACIE (Large Area Crop Inventory Experiment) intensive test sites using ground observations of the crops and measurements of their field areas based on current year rectified aerial photomaps. The field area and size distributions reported in the present investigation are derived from a representative subset of a stratified random sample of LACIE sample segments. In contrast to previous work, the obtained results indicate that most field-size distributions are not log-normally distributed. The most common field size observed in this study was 10 acres for most crops studied.

  20. Quantum key distribution using card, base station and trusted authority

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nordholt, Jane E.; Hughes, Richard John; Newell, Raymond Thorson

    Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trust authority. The keys can be used to set up secure communication, for authentication, for access control, or formore » other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.« less

  1. Quantum key distribution using card, base station and trusted authority

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nordholt, Jane Elizabeth; Hughes, Richard John; Newell, Raymond Thorson

    Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trusted authority. The keys can be used to set up secure communication, for authentication, for access control, or formore » other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.« less

  2. Property Values Associated with the Failure of Individual Links in a System with Multiple Weak and Strong Links.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Helton, Jon C.; Brooks, Dusty Marie; Sallaberry, Cedric Jean-Marie.

    Representations are developed and illustrated for the distribution of link property values at the time of link failure in the presence of aleatory uncertainty in link properties. The following topics are considered: (i) defining properties for weak links and strong links, (ii) cumulative distribution functions (CDFs) for link failure time, (iii) integral-based derivation of CDFs for link property at time of link failure, (iv) sampling-based approximation of CDFs for link property at time of link failure, (v) verification of integral-based and sampling-based determinations of CDFs for link property at time of link failure, (vi) distributions of link properties conditional onmore » time of link failure, and (vii) equivalence of two different integral-based derivations of CDFs for link property at time of link failure.« less

  3. Entropy-based derivation of generalized distributions for hydrometeorological frequency analysis

    NASA Astrophysics Data System (ADS)

    Chen, Lu; Singh, Vijay P.

    2018-02-01

    Frequency analysis of hydrometeorological and hydrological extremes is needed for the design of hydraulic and civil infrastructure facilities as well as water resources management. A multitude of distributions have been employed for frequency analysis of these extremes. However, no single distribution has been accepted as a global standard. Employing the entropy theory, this study derived five generalized distributions for frequency analysis that used different kinds of information encoded as constraints. These distributions were the generalized gamma (GG), the generalized beta distribution of the second kind (GB2), and the Halphen type A distribution (Hal-A), Halphen type B distribution (Hal-B) and Halphen type inverse B distribution (Hal-IB), among which the GG and GB2 distribution were previously derived by Papalexiou and Koutsoyiannis (2012) and the Halphen family was first derived using entropy theory in this paper. The entropy theory allowed to estimate parameters of the distributions in terms of the constraints used for their derivation. The distributions were tested using extreme daily and hourly rainfall data. Results show that the root mean square error (RMSE) values were very small, which indicated that the five generalized distributions fitted the extreme rainfall data well. Among them, according to the Akaike information criterion (AIC) values, generally the GB2 and Halphen family gave a better fit. Therefore, those general distributions are one of the best choices for frequency analysis. The entropy-based derivation led to a new way for frequency analysis of hydrometeorological extremes.

  4. Invasive Species Distribution Modeling (iSDM): Are absence data and dispersal constraints needed to predict actual distributions?

    Treesearch

    Tomáš Václavík; Ross K. Meentemeyer

    2009-01-01

    Species distribution models (SDMs) based on statistical relationships between occurrence data and underlying environmental conditions are increasingly used to predict spatial patterns of biological invasions and prioritize locations for early detection and control of invasion outbreaks. However, invasive species distribution models (iSDMs) face special challenges...

  5. Demonstration of the Competency-Based Curriculum for Distributive Education and Distributive Cooperative Training Programs. Final Report.

    ERIC Educational Resources Information Center

    Marshall Univ., Huntington, WV. Dept. of Occupational, Adult, and Safety Education.

    A core curriculum, training plans, and implementation guide developed by the project are included in this final report, which describes activities to resolve problems encountered by teachers using the IDECC (Interstate Distributive Education Curriculum Consortium) system designed for distributive education (DE) and diversified cooperative training…

  6. Some bivariate distributions for modeling the strength properties of lumber

    Treesearch

    Richard A. Johnson; James W. Evans; David W. Green

    Accurate modeling of the joint stochastic nature of the strength properties of dimension lumber is essential to the determination of reliability-based design safety factors. This report reviews the major techniques for obtaining bivariate distributions and then discusses bivariate distributions whose marginal distributions suggest they might be useful for modeling the...

  7. Emerald: an object-based language for distributed programming

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hutchinson, N.C.

    1987-01-01

    Distributed systems have become more common, however constructing distributed applications remains a very difficult task. Numerous operating systems and programming languages have been proposed that attempt to simplify the programming of distributed applications. Here a programing language called Emerald is presented that simplifies distributed programming by extending the concepts of object-based languages to the distributed environment. Emerald supports a single model of computation: the object. Emerald objects include private entities such as integers and Booleans, as well as shared, distributed entities such as compilers, directories, and entire file systems. Emerald objects may move between machines in the system, but objectmore » invocation is location independent. The uniform semantic model used for describing all Emerald objects makes the construction of distributed applications in Emerald much simpler than in systems where the differences in implementation between local and remote entities are visible in the language semantics. Emerald incorporates a type system that deals only with the specification of objects - ignoring differences in implementation. Thus, two different implementations of the same abstraction may be freely mixed.« less

  8. A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings

    DOE PAGES

    Gerber, Daniel L.; Vossos, Vagelis; Feng, Wei; ...

    2017-06-12

    Direct current (DC) power distribution has recently gained traction in buildings research due to the proliferation of on-site electricity generation and battery storage, and an increasing prevalence of internal DC loads. The research discussed in this paper uses Modelica-based simulation to compare the efficiency of DC building power distribution with an equivalent alternating current (AC) distribution. The buildings are all modeled with solar generation, battery storage, and loads that are representative of the most efficient building technology. A variety of paramet ric simulations determine how and when DC distribution proves advantageous. These simulations also validate previous studies that use simplermore » approaches and arithmetic efficiency models. This work shows that using DC distribution can be considerably more efficient: a medium sized office building using DC distribution has an expected baseline of 12% savings, but may also save up to 18%. In these results, the baseline simulation parameters are for a zero net energy (ZNE) building that can island as a microgrid. DC is most advantageous in buildings with large solar capacity, large battery capacity, and high voltage distribution.« less

  9. A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gerber, Daniel L.; Vossos, Vagelis; Feng, Wei

    Direct current (DC) power distribution has recently gained traction in buildings research due to the proliferation of on-site electricity generation and battery storage, and an increasing prevalence of internal DC loads. The research discussed in this paper uses Modelica-based simulation to compare the efficiency of DC building power distribution with an equivalent alternating current (AC) distribution. The buildings are all modeled with solar generation, battery storage, and loads that are representative of the most efficient building technology. A variety of paramet ric simulations determine how and when DC distribution proves advantageous. These simulations also validate previous studies that use simplermore » approaches and arithmetic efficiency models. This work shows that using DC distribution can be considerably more efficient: a medium sized office building using DC distribution has an expected baseline of 12% savings, but may also save up to 18%. In these results, the baseline simulation parameters are for a zero net energy (ZNE) building that can island as a microgrid. DC is most advantageous in buildings with large solar capacity, large battery capacity, and high voltage distribution.« less

  10. Spatial distribution of grape root borer (Lepidoptera: Sesiidae) infestations in Virginia vineyards and implications for sampling.

    PubMed

    Rijal, J P; Brewster, C C; Bergh, J C

    2014-06-01

    Grape root borer, Vitacea polistiformis (Harris) (Lepidoptera: Sesiidae) is a potentially destructive pest of grape vines, Vitis spp. in the eastern United States. After feeding on grape roots for ≍2 yr in Virginia, larvae pupate beneath the soil surface around the vine base. Adults emerge during July and August, leaving empty pupal exuviae on or protruding from the soil. Weekly collections of pupal exuviae from an ≍1-m-diameter weed-free zone around the base of a grid of sample vines in Virginia vineyards were conducted in July and August, 2008-2012, and their distribution was characterized using both nonspatial (dispersion) and spatial techniques. Taylor's power law showed a significant aggregation of pupal exuviae, based on data from 19 vineyard blocks. Combined use of geostatistical and Spatial Analysis by Distance IndicEs methods indicated evidence of an aggregated pupal exuviae distribution pattern in seven of the nine blocks used for those analyses. Grape root borer pupal exuviae exhibited spatial dependency within a mean distance of 8.8 m, based on the range values of best-fitted variograms. Interpolated and clustering index-based infestation distribution maps were developed to show the spatial pattern of the insect within the vineyard blocks. The temporal distribution of pupal exuviae showed that the majority of moths emerged during the 3-wk period spanning the third week of July and the first week of August. The spatial distribution of grape root borer pupal exuviae was used in combination with temporal moth emergence patterns to develop a quantitative and efficient sampling scheme to assess infestations.

  11. Scoring in genetically modified organism proficiency tests based on log-transformed results.

    PubMed

    Thompson, Michael; Ellison, Stephen L R; Owen, Linda; Mathieson, Kenneth; Powell, Joanne; Key, Pauline; Wood, Roger; Damant, Andrew P

    2006-01-01

    The study considers data from 2 UK-based proficiency schemes and includes data from a total of 29 rounds and 43 test materials over a period of 3 years. The results from the 2 schemes are similar and reinforce each other. The amplification process used in quantitative polymerase chain reaction determinations predicts a mixture of normal, binomial, and lognormal distributions dominated by the latter 2. As predicted, the study results consistently follow a positively skewed distribution. Log-transformation prior to calculating z-scores is effective in establishing near-symmetric distributions that are sufficiently close to normal to justify interpretation on the basis of the normal distribution.

  12. Heartbeat-based error diagnosis framework for distributed embedded systems

    NASA Astrophysics Data System (ADS)

    Mishra, Swagat; Khilar, Pabitra Mohan

    2012-01-01

    Distributed Embedded Systems have significant applications in automobile industry as steer-by-wire, fly-by-wire and brake-by-wire systems. In this paper, we provide a general framework for fault detection in a distributed embedded real time system. We use heartbeat monitoring, check pointing and model based redundancy to design a scalable framework that takes care of task scheduling, temperature control and diagnosis of faulty nodes in a distributed embedded system. This helps in diagnosis and shutting down of faulty actuators before the system becomes unsafe. The framework is designed and tested using a new simulation model consisting of virtual nodes working on a message passing system.

  13. Heartbeat-based error diagnosis framework for distributed embedded systems

    NASA Astrophysics Data System (ADS)

    Mishra, Swagat; Khilar, Pabitra Mohan

    2011-12-01

    Distributed Embedded Systems have significant applications in automobile industry as steer-by-wire, fly-by-wire and brake-by-wire systems. In this paper, we provide a general framework for fault detection in a distributed embedded real time system. We use heartbeat monitoring, check pointing and model based redundancy to design a scalable framework that takes care of task scheduling, temperature control and diagnosis of faulty nodes in a distributed embedded system. This helps in diagnosis and shutting down of faulty actuators before the system becomes unsafe. The framework is designed and tested using a new simulation model consisting of virtual nodes working on a message passing system.

  14. Feasibility study and preliminary design for fishing (TUNA) vessel fuel storage and distribution. Final report. Export trade information

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1995-07-01

    The report is divided into the following sections: (1) Introduction; (2) Conclusions and Recommendations; (3) Existing Conditions and Facilities for a Fuel Distribution Center; (4) Pacific Ocean Regional Tuna Fisheries and Resources; (5) Fishing Effort in the FSMEEZ 1992-1994; (6) Current Transshipping Operations in the Western Pacific Ocean; (7) Current and Probale Bunkering Practices of United States, Japanese, Koren, and Taiwanese Offshore-Based Vessels Operating in FSM and Adjacent Waters; (8) Shore-Based Fish-Handling/Processing; (9) Fuels Forecast; (10) Fuel Supply, Storage and Distribution; (11) Cost Estimates; (12) Economic Evaluation of Fuel Supply, Storage and Distribution.

  15. Inversion of particle-size distribution from angular light-scattering data with genetic algorithms.

    PubMed

    Ye, M; Wang, S; Lu, Y; Hu, T; Zhu, Z; Xu, Y

    1999-04-20

    A stochastic inverse technique based on a genetic algorithm (GA) to invert particle-size distribution from angular light-scattering data is developed. This inverse technique is independent of any given a priori information of particle-size distribution. Numerical tests show that this technique can be successfully applied to inverse problems with high stability in the presence of random noise and low susceptibility to the shape of distributions. It has also been shown that the GA-based inverse technique is more efficient in use of computing time than the inverse Monte Carlo method recently developed by Ligon et al. [Appl. Opt. 35, 4297 (1996)].

  16. Efficient entanglement distribution over 200 kilometers.

    PubMed

    Dynes, J F; Takesue, H; Yuan, Z L; Sharpe, A W; Harada, K; Honjo, T; Kamada, H; Tadanaga, O; Nishida, Y; Asobe, M; Shields, A J

    2009-07-06

    Here we report the first demonstration of entanglement distribution over a record distance of 200 km which is of sufficient fidelity to realize secure communication. In contrast to previous entanglement distribution schemes, we use detection elements based on practical avalanche photodiodes (APDs) operating in a self-differencing mode. These APDs are low-cost, compact and easy to operate requiring only electrical cooling to achieve high single photon detection efficiency. The self-differencing APDs in combination with a reliable parametric down-conversion source demonstrate that entanglement distribution over ultra-long distances has become both possible and practical. Consequently the outlook is extremely promising for real world entanglement-based communication between distantly separated parties.

  17. Draft Environmental Impact Statement. MX Deployment Area Selection and Land Withdrawal/Acquisition DEIS. Volume IV. Part II. Environmental Consequences to the Study Regions and Operating Base Vicinities.

    DTIC Science & Technology

    1980-12-01

    desert tortoise distribution at Coyote Spring OB and vicinity. 4-179 4.3.1.9-3 Utah Prairie Dog distribution and Proposed Action conceptual project...layout. 4-185 4.3.1.9-4 Distribution of Utah prairie dog in the vicinity of the Milford OB. 4-187 4.3.1.9-5 Distribution of Utah prairie dog in the...Coyote Spring. 4-180 4.3.1.9-2 Potential impact to the Utah prairie dog around operating bases (OBs) for the Proposed Action and Alternatives 1-8. 4-188

  18. Distributed sensor architecture for intelligent control that supports quality of control and quality of service.

    PubMed

    Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Simarro, Raúl; Benet, Ginés

    2015-02-25

    This paper is part of a study of intelligent architectures for distributed control and communications systems. The study focuses on optimizing control systems by evaluating the performance of middleware through quality of service (QoS) parameters and the optimization of control using Quality of Control (QoC) parameters. The main aim of this work is to study, design, develop, and evaluate a distributed control architecture based on the Data-Distribution Service for Real-Time Systems (DDS) communication standard as proposed by the Object Management Group (OMG). As a result of the study, an architecture called Frame-Sensor-Adapter to Control (FSACtrl) has been developed. FSACtrl provides a model to implement an intelligent distributed Event-Based Control (EBC) system with support to measure QoS and QoC parameters. The novelty consists of using, simultaneously, the measured QoS and QoC parameters to make decisions about the control action with a new method called Event Based Quality Integral Cycle. To validate the architecture, the first five Braitenberg vehicles have been implemented using the FSACtrl architecture. The experimental outcomes, demonstrate the convenience of using jointly QoS and QoC parameters in distributed control systems.

  19. Distributed Sensor Architecture for Intelligent Control that Supports Quality of Control and Quality of Service

    PubMed Central

    Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Simarro, Raúl; Benet, Ginés

    2015-01-01

    This paper is part of a study of intelligent architectures for distributed control and communications systems. The study focuses on optimizing control systems by evaluating the performance of middleware through quality of service (QoS) parameters and the optimization of control using Quality of Control (QoC) parameters. The main aim of this work is to study, design, develop, and evaluate a distributed control architecture based on the Data-Distribution Service for Real-Time Systems (DDS) communication standard as proposed by the Object Management Group (OMG). As a result of the study, an architecture called Frame-Sensor-Adapter to Control (FSACtrl) has been developed. FSACtrl provides a model to implement an intelligent distributed Event-Based Control (EBC) system with support to measure QoS and QoC parameters. The novelty consists of using, simultaneously, the measured QoS and QoC parameters to make decisions about the control action with a new method called Event Based Quality Integral Cycle. To validate the architecture, the first five Braitenberg vehicles have been implemented using the FSACtrl architecture. The experimental outcomes, demonstrate the convenience of using jointly QoS and QoC parameters in distributed control systems. PMID:25723145

  20. On the development of a new methodology in sub-surface parameterisation on the calibration of groundwater models

    NASA Astrophysics Data System (ADS)

    Klaas, D. K. S. Y.; Imteaz, M. A.; Sudiayem, I.; Klaas, E. M. E.; Klaas, E. C. M.

    2017-10-01

    In groundwater modelling, robust parameterisation of sub-surface parameters is crucial towards obtaining an agreeable model performance. Pilot point is an alternative in parameterisation step to correctly configure the distribution of parameters into a model. However, the methodology given by the current studies are considered less practical to be applied on real catchment conditions. In this study, a practical approach of using geometric features of pilot point and distribution of hydraulic gradient over the catchment area is proposed to efficiently configure pilot point distribution in the calibration step of a groundwater model. A development of new pilot point distribution, Head Zonation-based (HZB) technique, which is based on the hydraulic gradient distribution of groundwater flow, is presented. Seven models of seven zone ratios (1, 5, 10, 15, 20, 25 and 30) using HZB technique were constructed on an eogenetic karst catchment in Rote Island, Indonesia and their performances were assessed. This study also concludes some insights into the trade-off between restricting and maximising the number of pilot points and offers a new methodology for selecting pilot point properties and distribution method in the development of a physically-based groundwater model.

  1. New Educational Modules Using a Cyber-Distribution System Testbed

    DOE PAGES

    Xie, Jing; Bedoya, Juan Carlos; Liu, Chen-Ching; ...

    2018-03-30

    At Washington State University (WSU), a modern cyber-physical system testbed has been implemented based on an industry grade distribution management system (DMS) that is integrated with remote terminal units (RTUs), smart meters, and a solar photovoltaic (PV). In addition, the real model from the Avista Utilities distribution system in Pullman, WA, is modeled in DMS. The proposed testbed environment allows students and instructors to utilize these facilities for innovations in learning and teaching. For power engineering education, this testbed helps students understand the interaction between a cyber system and a physical distribution system through industrial level visualization. The testbed providesmore » a distribution system monitoring and control environment for students. Compared with a simulation based approach, the testbed brings the students' learning environment a step closer to the real world. The educational modules allow students to learn the concepts of a cyber-physical system and an electricity market through an integrated testbed. Furthermore, the testbed provides a platform in the study mode for students to practice working on a real distribution system model. Here, this paper describes the new educational modules based on the testbed environment. Three modules are described together with the underlying educational principles and associated projects.« less

  2. Entropy-based heavy tailed distribution transformation and visual analytics for monitoring massive network traffic

    NASA Astrophysics Data System (ADS)

    Han, Keesook J.; Hodge, Matthew; Ross, Virginia W.

    2011-06-01

    For monitoring network traffic, there is an enormous cost in collecting, storing, and analyzing network traffic datasets. Data mining based network traffic analysis has a growing interest in the cyber security community, but is computationally expensive for finding correlations between attributes in massive network traffic datasets. To lower the cost and reduce computational complexity, it is desirable to perform feasible statistical processing on effective reduced datasets instead of on the original full datasets. Because of the dynamic behavior of network traffic, traffic traces exhibit mixtures of heavy tailed statistical distributions or overdispersion. Heavy tailed network traffic characterization and visualization are important and essential tasks to measure network performance for the Quality of Services. However, heavy tailed distributions are limited in their ability to characterize real-time network traffic due to the difficulty of parameter estimation. The Entropy-Based Heavy Tailed Distribution Transformation (EHTDT) was developed to convert the heavy tailed distribution into a transformed distribution to find the linear approximation. The EHTDT linearization has the advantage of being amenable to characterize and aggregate overdispersion of network traffic in realtime. Results of applying the EHTDT for innovative visual analytics to real network traffic data are presented.

  3. New Educational Modules Using a Cyber-Distribution System Testbed

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xie, Jing; Bedoya, Juan Carlos; Liu, Chen-Ching

    At Washington State University (WSU), a modern cyber-physical system testbed has been implemented based on an industry grade distribution management system (DMS) that is integrated with remote terminal units (RTUs), smart meters, and a solar photovoltaic (PV). In addition, the real model from the Avista Utilities distribution system in Pullman, WA, is modeled in DMS. The proposed testbed environment allows students and instructors to utilize these facilities for innovations in learning and teaching. For power engineering education, this testbed helps students understand the interaction between a cyber system and a physical distribution system through industrial level visualization. The testbed providesmore » a distribution system monitoring and control environment for students. Compared with a simulation based approach, the testbed brings the students' learning environment a step closer to the real world. The educational modules allow students to learn the concepts of a cyber-physical system and an electricity market through an integrated testbed. Furthermore, the testbed provides a platform in the study mode for students to practice working on a real distribution system model. Here, this paper describes the new educational modules based on the testbed environment. Three modules are described together with the underlying educational principles and associated projects.« less

  4. The Reliability Estimation for the Open Function of Cabin Door Affected by the Imprecise Judgment Corresponding to Distribution Hypothesis

    NASA Astrophysics Data System (ADS)

    Yu, Z. P.; Yue, Z. F.; Liu, W.

    2018-05-01

    With the development of artificial intelligence, more and more reliability experts have noticed the roles of subjective information in the reliability design of complex system. Therefore, based on the certain numbers of experiment data and expert judgments, we have divided the reliability estimation based on distribution hypothesis into cognition process and reliability calculation. Consequently, for an illustration of this modification, we have taken the information fusion based on intuitional fuzzy belief functions as the diagnosis model of cognition process, and finished the reliability estimation for the open function of cabin door affected by the imprecise judgment corresponding to distribution hypothesis.

  5. Synaptic shot noise and conductance fluctuations affect the membrane voltage with equal significance.

    PubMed

    Richardson, Magnus J E; Gerstner, Wulfram

    2005-04-01

    The subthreshold membrane voltage of a neuron in active cortical tissue is a fluctuating quantity with a distribution that reflects the firing statistics of the presynaptic population. It was recently found that conductance-based synaptic drive can lead to distributions with a significant skew. Here it is demonstrated that the underlying shot noise caused by Poissonian spike arrival also skews the membrane distribution, but in the opposite sense. Using a perturbative method, we analyze the effects of shot noise on the distribution of synaptic conductances and calculate the consequent voltage distribution. To first order in the perturbation theory, the voltage distribution is a gaussian modulated by a prefactor that captures the skew. The gaussian component is identical to distributions derived using current-based models with an effective membrane time constant. The well-known effective-time-constant approximation can therefore be identified as the leading-order solution to the full conductance-based model. The higher-order modulatory prefactor containing the skew comprises terms due to both shot noise and conductance fluctuations. The diffusion approximation misses these shot-noise effects implying that analytical approaches such as the Fokker-Planck equation or simulation with filtered white noise cannot be used to improve on the gaussian approximation. It is further demonstrated that quantities used for fitting theory to experiment, such as the voltage mean and variance, are robust against these non-Gaussian effects. The effective-time-constant approximation is therefore relevant to experiment and provides a simple analytic base on which other pertinent biological details may be added.

  6. ON A POSSIBLE SIZE/COLOR RELATIONSHIP IN THE KUIPER BELT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pike, R. E.; Kavelaars, J. J., E-mail: repike@uvic.ca

    2013-10-01

    Color measurements and albedo distributions introduce non-intuitive observational biases in size-color relationships among Kuiper Belt Objects (KBOs) that cannot be disentangled without a well characterized sample population with systematic photometry. Peixinho et al. report that the form of the KBO color distribution varies with absolute magnitude, H. However, Tegler et al. find that KBO color distributions are a property of object classification. We construct synthetic models of observed KBO colors based on two B-R color distribution scenarios: color distribution dependent on H magnitude (H-Model) and color distribution based on object classification (Class-Model). These synthetic B-R color distributions were modified tomore » account for observational flux biases. We compare our synthetic B-R distributions to the observed ''Hot'' and ''Cold'' detected objects from the Canada-France Ecliptic Plane Survey and the Meudon Multicolor Survey. For both surveys, the Hot population color distribution rejects the H-Model, but is well described by the Class-Model. The Cold objects reject the H-Model, but the Class-Model (while not statistically rejected) also does not provide a compelling match for data. Although we formally reject models where the structure of the color distribution is a strong function of H magnitude, we also do not find that a simple dependence of color distribution on orbit classification is sufficient to describe the color distribution of classical KBOs.« less

  7. Learning from Multiple Collaborating Intelligent Tutors: An Agent-based Approach.

    ERIC Educational Resources Information Center

    Solomos, Konstantinos; Avouris, Nikolaos

    1999-01-01

    Describes an open distributed multi-agent tutoring system (MATS) and discusses issues related to learning in such open environments. Topics include modeling a one student-many teachers approach in a computer-based learning context; distributed artificial intelligence; implementation issues; collaboration; and user interaction. (Author/LRW)

  8. DataHub knowledge based assistance for science visualization and analysis using large distributed databases

    NASA Technical Reports Server (NTRS)

    Handley, Thomas H., Jr.; Collins, Donald J.; Doyle, Richard J.; Jacobson, Allan S.

    1991-01-01

    Viewgraphs on DataHub knowledge based assistance for science visualization and analysis using large distributed databases. Topics covered include: DataHub functional architecture; data representation; logical access methods; preliminary software architecture; LinkWinds; data knowledge issues; expert systems; and data management.

  9. Managing Distributed Systems with Smart Subscriptions

    NASA Technical Reports Server (NTRS)

    Filman, Robert E.; Lee, Diana D.; Swanson, Keith (Technical Monitor)

    2000-01-01

    We describe an event-based, publish-and-subscribe mechanism based on using 'smart subscriptions' to recognize weakly-structured events. We present a hierarchy of subscription languages (propositional, predicate, temporal and agent) and algorithms for efficiently recognizing event matches. This mechanism has been applied to the management of distributed applications.

  10. EFFECT OF NITRATE-BASED BIOREMEDIATION ON CONTAMINANT DISTRIBUTION AND SEDIMENT TOXICITY-COLUMN STUDY

    EPA Science Inventory

    A laboratory column study was set up to evaluate changes in contaminant distribution and sediment toxicity following nitrate-based bioremediation and to correlate toxicity reduction with loss of fuel components. Glass columns were packed with sediment from an aquifer that had be...

  11. Crumble analysis of the historic sympatric distribution between Dendrortyx macroura and D. barbatus (Aves: Galliformes)

    PubMed Central

    2017-01-01

    In Mexico, the Long-tailed Wood-Partridge (Dendrortyx macroura) is distributed in the mountains of the Trans-Mexican Volcanic Belt, Sierra Madre del Sur and Sierra Norte de Oaxaca; while the Bearded Wood-Partridge (D. barbatus) is distributed in the Sierra Madre Oriental (SMO). There is a controversial overlap in distribution (sympatry) between these two species (on the Cofre de Perote and Pico de Orizaba volcanoes, SMO and Sierra Norte de Oaxaca), based on the ambiguity and current lack of information regarding the distribution of these two species. In order to disentangle the possible presence of both species in the area of sympatry, we conducted a crumble analysis of the historic knowledge regarding the geographic distribution of both species, based on a review of scientific literature, database records, the specimen examination (in ornithological collections), field work and a reconstruction of the distribution range based on Ecological Niche Modeling. Our results support the presence of only one of these two species in the overlapping area, rejecting the existence of such an area of sympatry between the two species. We discuss alternative hypotheses that could explain the historically reported distribution pattern: 1) an error in the single existing historical record; 2) a possible local extinction of the species and 3) the past existence of interspecific competition that has since been resolved under the principle of competitive exclusion. We propose that the Santo Domingo River in northern Oaxaca and western slope of the Sierra Madre Oriental, mark the distribution limits between these species. PMID:28863140

  12. Evaluating De-centralised and Distributional Options for the Distributed Electronic Warfare Situation Awareness and Response Test Bed

    DTIC Science & Technology

    2013-12-01

    effectors (deployed on ground based or aerial platforms) to detect , identify, locate, track or suppress stationary or slow moving surface based RF...ground based or aerial platforms) to detect , identify, locate, track or suppress stationary or slow moving surface based RF emitting targets. In the...Electronic Support EO Electro-Optic FPGAs Field Programmable Gate Arrays IR Infra-red LADAR Laser Detection and Ranging OSX Mac OS X; the apple

  13. Army Logistician. Volume 39, Issue 2, March-April 2007

    DTIC Science & Technology

    2007-04-01

    Most Army Reduces Tactical Supply System Footprint by thoMas h. aMent, jr. Centralizing all of the Army’s Corps/Theater Automated Data Processing...Middleware, which comprises both hardware and software, revises data in the Standard Army Retail Supply System (SARSS), thereby extending the use of the...Logistics: Supply Based or Distribution Based? The Changing Face of Fuel Management Combat Logistics Patrol Methodology Distribution-Based

  14. Information, Understanding, and Influence: An Agency Theory Strategy for Air Base Communications and Cyberspace Support

    DTIC Science & Technology

    2014-05-01

    DISTRIBUTION A. Approved for public release: distribution unlimited. INFORMATION, UNDERSTANDING, AND INFLUENCE: AN AGENCY THEORY STRATEGY ...Influence: An Agency Theory Strategy For Air Base Communications And Cyberspace Support 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...present communications and cyberspace support organizations. Next, it introduces a strategy based on this analysis to bring information, understanding

  15. General specifications for the development of a USL/DBMS NASA/PC R and D distributed workstation

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Chum, Frank Y.

    1984-01-01

    The general specifications for the development of a PC-based distributed workstation (PCDWS) for an information storage and retrieval systems environment are defined. This research proposes the development of a PCDWS prototype as part of the University of Southwestern Louisiana Data Base Management System (USL/DBMS) NASA/PC R and D project in the PC-based workstation environment.

  16. Community-Based Social Networks: Generation of Power Law Degree Distribution and IP Solutions to the KPP

    ERIC Educational Resources Information Center

    Wu, Wentao

    2012-01-01

    The objective of this thesis is two-fold: (1) to investigate the degree distribution property of community-based social networks (CSNs) and (2) to provide solutions to a pertinent problem, the Key Player Problem. In the first part of this thesis, we consider a growing community-based network in which the ability of nodes competing for links to new…

  17. Research on Comprehensive Evaluation Method for Heating Project Based on Analytic Hierarchy Processing

    NASA Astrophysics Data System (ADS)

    Han, Shenchao; Yang, Yanchun; Liu, Yude; Zhang, Peng; Li, Siwei

    2018-01-01

    It is effective to reduce haze in winter by changing the distributed heat supply system. Thus, the studies on comprehensive index system and scientific evaluation method of distributed heat supply project are essential. Firstly, research the influence factors of heating modes, and an index system with multiple dimension including economic, environmental, risk and flexibility was built and all indexes were quantified. Secondly, a comprehensive evaluation method based on AHP was put forward to analyze the proposed multiple and comprehensive index system. Lastly, the case study suggested that supplying heat with electricity has great advantage and promotional value. The comprehensive index system of distributed heating supply project and evaluation method in this paper can evaluate distributed heat supply project effectively and provide scientific support for choosing the distributed heating project.

  18. Integration of piezo-capacitive and piezo-electric nanoweb based pressure sensors for imaging of static and dynamic pressure distribution.

    PubMed

    Jeong, Y J; Oh, T I; Woo, E J; Kim, K J

    2017-07-01

    Recently, highly flexible and soft pressure distribution imaging sensor is in great demand for tactile sensing, gait analysis, ubiquitous life-care based on activity recognition, and therapeutics. In this study, we integrate the piezo-capacitive and piezo-electric nanowebs with the conductive fabric sheets for detecting static and dynamic pressure distributions on a large sensing area. Electrical impedance tomography (EIT) and electric source imaging are applied for reconstructing pressure distribution images from measured current-voltage data on the boundary of the hybrid fabric sensor. We evaluated the piezo-capacitive nanoweb sensor, piezo-electric nanoweb sensor, and hybrid fabric sensor. The results show the feasibility of static and dynamic pressure distribution imaging from the boundary measurements of the fabric sensors.

  19. Vehicle Routing Problem Using Genetic Algorithm with Multi Compartment on Vegetable Distribution

    NASA Astrophysics Data System (ADS)

    Kurnia, Hari; Gustri Wahyuni, Elyza; Cergas Pembrani, Elang; Gardini, Syifa Tri; Kurnia Aditya, Silfa

    2018-03-01

    The problem that is often gained by the industries of managing and distributing vegetables is how to distribute vegetables so that the quality of the vegetables can be maintained properly. The problems encountered include optimal route selection and little travel time or so-called TSP (Traveling Salesman Problem). These problems can be modeled using the Vehicle Routing Problem (VRP) algorithm with rating ranking, a cross order based crossing, and also order based mutation mutations on selected chromosomes. This study uses limitations using only 20 market points, 2 point warehouse (multi compartment) and 5 vehicles. It is determined that for one distribution, one vehicle can only distribute to 4 market points only from 1 particular warehouse, and also one such vehicle can only accommodate 100 kg capacity.

  20. Empirical likelihood-based tests for stochastic ordering

    PubMed Central

    BARMI, HAMMOU EL; MCKEAGUE, IAN W.

    2013-01-01

    This paper develops an empirical likelihood approach to testing for the presence of stochastic ordering among univariate distributions based on independent random samples from each distribution. The proposed test statistic is formed by integrating a localized empirical likelihood statistic with respect to the empirical distribution of the pooled sample. The asymptotic null distribution of this test statistic is found to have a simple distribution-free representation in terms of standard Brownian bridge processes. The approach is used to compare the lengths of rule of Roman Emperors over various historical periods, including the “decline and fall” phase of the empire. In a simulation study, the power of the proposed test is found to improve substantially upon that of a competing test due to El Barmi and Mukerjee. PMID:23874142

  1. Application of Bayesian Classification to Content-Based Data Management

    NASA Technical Reports Server (NTRS)

    Lynnes, Christopher; Berrick, S.; Gopalan, A.; Hua, X.; Shen, S.; Smith, P.; Yang, K-Y.; Wheeler, K.; Curry, C.

    2004-01-01

    The high volume of Earth Observing System data has proven to be challenging to manage for data centers and users alike. At the Goddard Earth Sciences Distributed Active Archive Center (GES DAAC), about 1 TB of new data are archived each day. Distribution to users is also about 1 TB/day. A substantial portion of this distribution is MODIS calibrated radiance data, which has a wide variety of uses. However, much of the data is not useful for a particular user's needs: for example, ocean color users typically need oceanic pixels that are free of cloud and sun-glint. The GES DAAC is using a simple Bayesian classification scheme to rapidly classify each pixel in the scene in order to support several experimental content-based data services for near-real-time MODIS calibrated radiance products (from Direct Readout stations). Content-based subsetting would allow distribution of, say, only clear pixels to the user if desired. Content-based subscriptions would distribute data to users only when they fit the user's usability criteria in their area of interest within the scene. Content-based cache management would retain more useful data on disk for easy online access. The classification may even be exploited in an automated quality assessment of the geolocation product. Though initially to be demonstrated at the GES DAAC, these techniques have applicability in other resource-limited environments, such as spaceborne data systems.

  2. WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Warrell, G; Shvydka, D; Parsai, E I

    Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapymore » seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less than that for the previously-presented NiCu-based seeds.« less

  3. The impact of productivity-based incentives on faculty salary-based compensation.

    PubMed

    Miller, Ronald D; Cohen, Neal H

    2005-07-01

    In industry and academic anesthesia departments, incentives and bonus payments based on productivity are accounting for an increasing proportion of a total compensation. When incentives are primarily based on clinical productivity, the impact on the distribution of total compensation to the faculty is not known. We compared a pure salary-based compensation methodology based entirely on academic rank to salary plus incentives and/or clinical productivity compensation (i.e., billable hours). The change in compensation methodology resulted in two major findings. First, the productivity-based compensation resulted in a large increase in the variability of total compensation among faculty, especially at the Assistant Professor rank. Second, the mean difference in total compensation between Assistant and Full Professors decreased. The authors conclude that this particular incentive plan, primarily directed toward clinical productivity, dramatically changed the distribution of total compensation in favor of junior faculty. Although not analytically investigated, the potential impact of these changes on faculty morale and distribution of faculty activities is discussed.

  4. Base stock system for patient vs impatient customers with varying demand distribution

    NASA Astrophysics Data System (ADS)

    Fathima, Dowlath; Uduman, P. Sheik

    2013-09-01

    An optimal Base-Stock inventory policy for Patient and Impatient Customers using finite-horizon models is examined. The Base stock system for Patient and Impatient customers is a different type of inventory policy. In case of the model I, Base stock for Patient customer case is evaluated using the Truncated Exponential Distribution. The model II involves the study of Base-stock inventory policies for Impatient customer. A study on these systems reveals that the Customers wait until the arrival of the next order or the customers leaves the system which leads to lost sale. In both the models demand during the period [0, t] is taken to be a random variable. In this paper, Truncated Exponential Distribution satisfies the Base stock policy for the patient customer as a continuous model. So far the Base stock for Impatient Customers leaded to a discrete case but, in this paper we have modeled this condition into a continuous case. We justify this approach mathematically and also numerically.

  5. Research in Functionally Distributed Computer Systems Development. Volume XII. Design Considerations in Distributed Data Base Management Systems.

    DTIC Science & Technology

    1977-04-01

    task of data organization, management, and storage has been given to a select group of specialists . These specialists (the Data Base Administrators...report writers, etc.) the task of data organi?9tion, management, and storage has been given to a select group of specialists . These specialists (the...distributed DBMS Involves first identifying a set of two or more tasks blocking each other from a collection of shared 12 records. Once the set of

  6. Experimental study of low-cost fiber optic distributed temperature sensor system performance

    NASA Astrophysics Data System (ADS)

    Dashkov, Michael V.; Zharkov, Alexander D.

    2016-03-01

    The distributed control of temperature is an actual task for various application such as oil & gas fields, high-voltage power lines, fire alarm systems etc. The most perspective are optical fiber distributed temperature sensors (DTS). They have advantages on accuracy, resolution and range, but have a high cost. Nevertheless, for some application the accuracy of measurement and localization aren't so important as cost. The results of an experimental study of low-cost Raman based DTS based on standard OTDR are represented.

  7. Graded-index fibers, Wigner-distribution functions, and the fractional Fourier transform.

    PubMed

    Mendlovic, D; Ozaktas, H M; Lohmann, A W

    1994-09-10

    Two definitions of a fractional Fourier transform have been proposed previously. One is based on the propagation of a wave field through a graded-index medium, and the other is based on rotating a function's Wigner distribution. It is shown that both definitions are equivalent. An important result of this equivalency is that the Wigner distribution of a wave field rotates as the wave field propagates through a quadratic graded-index medium. The relation with ray-optics phase space is discussed.

  8. Optimization of orthotropic distributed-mode loudspeaker using attached masses and multi-exciters.

    PubMed

    Lu, Guochao; Shen, Yong; Liu, Ziyun

    2012-02-01

    Based on the orthotropic model of the plate, the method to optimize the sound response of the distributed-mode loudspeaker (DML) using the attached masses and the multi-exciters has been investigated. The attached masses method will rebuild the modes distribution of the plate, based on which multi-exciter method will smooth the sound response. The results indicate that the method can be used to optimize the sound response of the DML. © 2012 Acoustical Society of America

  9. LWT Based Sensor Node Signal Processing in Vehicle Surveillance Distributed Sensor Network

    NASA Astrophysics Data System (ADS)

    Cha, Daehyun; Hwang, Chansik

    Previous vehicle surveillance researches on distributed sensor network focused on overcoming power limitation and communication bandwidth constraints in sensor node. In spite of this constraints, vehicle surveillance sensor node must have signal compression, feature extraction, target localization, noise cancellation and collaborative signal processing with low computation and communication energy dissipation. In this paper, we introduce an algorithm for light-weight wireless sensor node signal processing based on lifting scheme wavelet analysis feature extraction in distributed sensor network.

  10. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Weiguo, E-mail: wang_weiguo@vip.163.com

    High purity (99.99%) iron samples were cold rolled with a thickness reduction of 87% followed by a annealing at 620 °C for 15 and 45 min, then the grain boundary plane distributions were characterized by electron backscatter diffraction and a stereology and statistics based five parameter analysis. The results showed that the grain boundary planes were mainly distributed on (1 0 0) and such distribution was enhanced obviously when the holding time of annealing increased from 15 to 45 min during which an extensive grain growth and a dramatic texture evolution took place. Further analysis indicated such distribution was largelymore » due to the rotation of grain boundary planes of the [1 0 0] misoriented grains. Additionally, it was also observed that some random boundaries of [1 0 0] misoriented grains were changing from asymmetrical tilt into (1 0 0)/(− 1 0 0) twist when annealing proceeded from 15 to 45 min. Based on the present work and the results reported by other investigators, it was suggested that the chemistry appeared to be critical in determining the grain boundary plane distribution in iron based materials. - Highlights: •Grain boundary (GB) plane distribution (GBPD) in a high purity (99.99%) was studied. •GB planes are mainly distributed on (1 0 0) in the cold rolled and annealed samples. •Such distribution is largely due to the rotation of GB planes of [100] misoriented grains. •Some [1 0 0] asymmetrical tilt boundaries are evolving into twist ones during annealing.« less

  11. Pan-European comparison of candidate distributions for climatological drought indices, SPI and SPEI

    NASA Astrophysics Data System (ADS)

    Stagge, James; Tallaksen, Lena; Gudmundsson, Lukas; Van Loon, Anne; Stahl, Kerstin

    2013-04-01

    Drought indices are vital to objectively quantify and compare drought severity, duration, and extent across regions with varied climatic and hydrologic regimes. The Standardized Precipitation Index (SPI), a well-reviewed meterological drought index recommended by the WMO, and its more recent water balance variant, the Standardized Precipitation-Evapotranspiration Index (SPEI) both rely on selection of univariate probability distributions to normalize the index, allowing for comparisons across climates. The SPI, considered a universal meteorological drought index, measures anomalies in precipitation, whereas the SPEI measures anomalies in climatic water balance (precipitation minus potential evapotranspiration), a more comprehensive measure of water availability that incorporates temperature. Many reviewers recommend use of the gamma (Pearson Type III) distribution for SPI normalization, while developers of the SPEI recommend use of the three parameter log-logistic distribution, based on point observation validation. Before the SPEI can be implemented at the pan-European scale, it is necessary to further validate the index using a range of candidate distributions to determine sensitivity to distribution selection, identify recommended distributions, and highlight those instances where a given distribution may not be valid. This study rigorously compares a suite of candidate probability distributions using WATCH Forcing Data, a global, historical (1958-2001) climate dataset based on ERA40 reanalysis with 0.5 x 0.5 degree resolution and bias-correction based on CRU-TS2.1 observations. Using maximum likelihood estimation, alternative candidate distributions are fit for the SPI and SPEI across the range of European climate zones. When evaluated at this scale, the gamma distribution for the SPI results in negatively skewed values, exaggerating the index severity of extreme dry conditions, while decreasing the index severity of extreme high precipitation. This bias is particularly notable for shorter aggregation periods (1-6 months) during the summer months in southern Europe (below 45° latitude), and can partially be attributed to distribution fitting difficulties in semi-arid regions where monthly precipitation totals cluster near zero. By contrast, the SPEI has potential for avoiding this fitting difficulty because it is not bounded by zero. However, the recommended log-logistic distribution produces index values with less variation than the standard normal distribution. Among the alternative candidate distributions, the best fit distribution and the distribution parameters vary in space and time, suggesting regional commonalities within hydroclimatic regimes, as discussed further in the presentation.

  12. The relative roles of ANC and EPI in the continuous distribution of LLINs: a qualitative study in four countries.

    PubMed

    Theiss-Nyland, Katherine; Koné, Diakalia; Karema, Corine; Ejersa, Waqo; Webster, Jayne; Lines, Jo

    2017-05-01

    The continuous distribution of long-lasting insecticidal nets (LLINs) for malaria prevention, through the antenatal care (ANC) and the Expanded Programme on Immunizations (EPI), is recommended by the WHO to improve and maintain LLIN coverage. Despite these recommendations, little is known about the relative strengths and weaknesses of the ANC and EPI-based LLIN distribution. This study aimed to explore and compare the roles of the ANC and EPI for LLIN distribution in four African countries. In a qualitative evaluation of continuous distribution through the ANC and EPI, semi-structured, individual and group interviews were conducted in Kenya, Malawi, Mali, and Rwanda. Respondents included national, sub-national, and facility-level health staff, and were selected to capture a range of roles related to malaria, ANC and EPI programmes. Policies, guidelines, and data collection tools were reviewed as a means of triangulation to assess the structure of LLIN distribution, and the methods of data collection and reporting for malaria, ANC and EPI programmes. In the four countries visited, distribution of LLINs was more effectively integrated through ANC than through EPI because of a) stronger linkages and involvement between malaria and reproductive health programmes, as compared to malaria and EPI, and b) more complete programme monitoring for ANC-based distribution, compared to EPI-based distribution. Opportunities for improving the distribution of LLINs through these channels exist, especially in the case of EPI. For both ANC and EPI, integrated distribution of LLINs has the potential to act as an incentive, improving the already strong coverage of both these essential services. The collection and reporting of data on LLINs distributed through the ANC and EPI can provide insight into the performance of LLIN distribution within these programmes. Greater attention to data collection and use, by both the global malaria community, and the integrated programmes, can improve this distribution channel strength and effectiveness. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2016; all rights reserved.

  13. Validation of temporal and spatial consistency of facility- and speed-specific vehicle-specific power distributions for emission estimation: A case study in Beijing, China.

    PubMed

    Zhai, Zhiqiang; Song, Guohua; Lu, Hongyu; He, Weinan; Yu, Lei

    2017-09-01

    Vehicle-specific power (VSP) has been found to be highly correlated with vehicle emissions. It is used in many studies on emission modeling such as the MOVES (Motor Vehicle Emissions Simulator) model. The existing studies develop specific VSP distributions (or OpMode distribution in MOVES) for different road types and various average speeds to represent the vehicle operating modes on road. However, it is still not clear if the facility- and speed-specific VSP distributions are consistent temporally and spatially. For instance, is it necessary to update periodically the database of the VSP distributions in the emission model? Are the VSP distributions developed in the city central business district (CBD) area applicable to its suburb area? In this context, this study examined the temporal and spatial consistency of the facility- and speed-specific VSP distributions in Beijing. The VSP distributions in different years and in different areas are developed, based on real-world vehicle activity data. The root mean square error (RMSE) is employed to quantify the difference between the VSP distributions. The maximum differences of the VSP distributions between different years and between different areas are approximately 20% of that between different road types. The analysis of the carbon dioxide (CO 2 ) emission factor indicates that the temporal and spatial differences of the VSP distributions have no significant impact on vehicle emission estimation, with relative error of less than 3%. The temporal and spatial differences have no significant impact on the development of the facility- and speed-specific VSP distributions for the vehicle emission estimation. The database of the specific VSP distributions in the VSP-based emission models can maintain in terms of time. Thus, it is unnecessary to update the database regularly, and it is reliable to use the history vehicle activity data to forecast the emissions in the future. In one city, the areas with less data can still develop accurate VSP distributions based on better data from other areas.

  14. Improving flood forecasting capability of physically based distributed hydrological models by parameter optimization

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Li, J.; Xu, H.

    2016-01-01

    Physically based distributed hydrological models (hereafter referred to as PBDHMs) divide the terrain of the whole catchment into a number of grid cells at fine resolution and assimilate different terrain data and precipitation to different cells. They are regarded to have the potential to improve the catchment hydrological process simulation and prediction capability. In the early stage, physically based distributed hydrological models are assumed to derive model parameters from the terrain properties directly, so there is no need to calibrate model parameters. However, unfortunately the uncertainties associated with this model derivation are very high, which impacted their application in flood forecasting, so parameter optimization may also be necessary. There are two main purposes for this study: the first is to propose a parameter optimization method for physically based distributed hydrological models in catchment flood forecasting by using particle swarm optimization (PSO) algorithm and to test its competence and to improve its performances; the second is to explore the possibility of improving physically based distributed hydrological model capability in catchment flood forecasting by parameter optimization. In this paper, based on the scalar concept, a general framework for parameter optimization of the PBDHMs for catchment flood forecasting is first proposed that could be used for all PBDHMs. Then, with the Liuxihe model as the study model, which is a physically based distributed hydrological model proposed for catchment flood forecasting, the improved PSO algorithm is developed for the parameter optimization of the Liuxihe model in catchment flood forecasting. The improvements include adoption of the linearly decreasing inertia weight strategy to change the inertia weight and the arccosine function strategy to adjust the acceleration coefficients. This method has been tested in two catchments in southern China with different sizes, and the results show that the improved PSO algorithm could be used for the Liuxihe model parameter optimization effectively and could improve the model capability largely in catchment flood forecasting, thus proving that parameter optimization is necessary to improve the flood forecasting capability of physically based distributed hydrological models. It also has been found that the appropriate particle number and the maximum evolution number of PSO algorithm used for the Liuxihe model catchment flood forecasting are 20 and 30 respectively.

  15. MADE 2. Marketing and Distributive Education Competency Based Curriculum Guide.

    ERIC Educational Resources Information Center

    New Jersey State Dept. of Education, Trenton. Div. of Vocational Education.

    This curriculum guide is one in a series of three competency-based instructional materials dealing with marketing and distributive education (MADE). Covered in the individual sections of the guide are the following topics: job orientation (personal appearance, job opportunities, job interviews, basic skills, training plans, legal requirements, and…

  16. Simulations inform design of regional occupancy-based monitoring for a sparsely distributed, territorial species

    Treesearch

    Quresh S. Latif; Martha M. Ellis; Victoria A. Saab; Kim Mellen-McLean

    2017-01-01

    Sparsely distributed species attract conservation concern, but insufficient information on population trends challenges conservation and funding prioritization. Occupancy-based monitoring is attractive for these species, but appropriate sampling design and inference depend on particulars of the study system. We employed spatially explicit simulations to identify...

  17. DISTRIBUTED GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEM EMISSION OFFSET ASSESSMENT: STATISTICAL TEST OF SIMULATED- AND MEASURED-BASED DATA

    EPA Science Inventory

    This study assessed the pollutant emission offset potential of distributed grid-connected photovoltaic (PV) power systems. Computer-simulated performance results were utilized for 211 PV systems located across the U.S. The PV systems' monthly electrical energy outputs were based ...

  18. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... considering the number of samples in the background data base, the data distribution, and the range of the... the background data base, the data distribution, and the range of the concentration values for each... samples collected to establish ground-water quality data must be consistent with the appropriate...

  19. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... considering the number of samples in the background data base, the data distribution, and the range of the... the background data base, the data distribution, and the range of the concentration values for each... samples collected to establish ground-water quality data must be consistent with the appropriate...

  20. Distance-Based and Distributed Learning: A Decision Tool for Education Leaders.

    ERIC Educational Resources Information Center

    McGraw, Tammy M.; Ross, John D.

    This decision tool presents a progression of data collection and decision-making strategies that can increase the effectiveness of distance-based or distributed learning instruction. A narrative and flow chart cover the following steps: (1) basic assumptions, including purpose of instruction, market scan, and financial resources; (2) needs…

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