Sample records for model significantly overestimates

  1. Significant overestimation of global aerosol optical thickness by MODIS over land

    Institute of Scientific and Technical Information of China (English)

    XIA Xiang'ao


    Global aerosol optical thickness (AOT)data over land obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) are evaluated through comparisons with AOT data retrieved by Aerosol Robotic Network (AERONET). In general,MODIS overestimates AOT except at a few AERONET sites in Africa and eastern Asia. MODIS/AOTs are, on average, larger than AERONET/AOTs by 0.041 and 0.090 at 470 nm and 660 nm, respectively. The AOT bias at 660 nm is significantly correlated to the surface reflectance at 2130 nm. Both facts suggest that the underestimation of the surface reflectance is the principal reason for this bias at 660 nm. To use the MODIS/AOT at 470 nm is strongly recommended because it is much more reliable than the AOT at 660 nm.

  2. The total infrared luminosity may significantly overestimate the star formation rate of recently quenched galaxies

    CERN Document Server

    Hayward, Christopher C; Ashby, Matthew L N; Fazio, Giovanni; Hernquist, Lars; Martínez-Galarza, Juan Rafael; Noeske, Kai; Smith, Howard A; Wuyts, Stijn; Zezas, Andreas


    The total infrared (IR) luminosity is very useful for estimating the star formation rate (SFR) of galaxies, but converting the IR luminosity into an SFR relies on assumptions that do not hold for all galaxies. We test the effectiveness of the IR luminosity as an SFR indicator by applying it to synthetic spectral energy distributions generated from three-dimensional hydrodynamical simulations of isolated disc galaxies and galaxy mergers. In general, the SFR inferred from the IR luminosity agrees well with the true instantaneous SFR of the simulated galaxies. However, for the major mergers in which a strong starburst is induced, the SFR inferred from the IR luminosity can overestimate the instantaneous SFR during the post-starburst phase by greater than two orders of magnitude. Even though the instantaneous SFR decreases rapidly after the starburst, the stars that were formed in the starburst remain dust-obscured and thus produce significant IR luminosity. Consequently, use of the IR luminosity as an SFR indica...

  3. Mitotic figure counts are significantly overestimated in resection specimens of invasive breast carcinomas. (United States)

    Lehr, Hans-Anton; Rochat, Candice; Schaper, Cornelia; Nobile, Antoine; Shanouda, Sherien; Vijgen, Sandrine; Gauthier, Arnaud; Obermann, Ellen; Leuba, Susana; Schmidt, Marcus; C, Curzio Ruegg; Delaloye, Jean-Francois; Simiantonaki, Nectaria; Schaefer, Stephan C


    Several authors have demonstrated an increased number of mitotic figures in breast cancer resection specimen when compared with biopsy material. This has been ascribed to a sampling artifact where biopsies are (i) either too small to allow formal mitotic figure counting or (ii) not necessarily taken form the proliferating tumor periphery. Herein, we propose a different explanation for this phenomenon. Biopsy and resection material of 52 invasive ductal carcinomas was studied. We counted mitotic figures in 10 representative high power fields and quantified MIB-1 immunohistochemistry by visual estimation, counting and image analysis. We found that mitotic figures were elevated by more than three-fold on average in resection specimen over biopsy material from the same tumors (20±6 vs 6±2 mitoses per 10 high power fields, P=0.008), and that this resulted in a relative diminution of post-metaphase figures (anaphase/telophase), which made up 7% of all mitotic figures in biopsies but only 3% in resection specimen (Pmitotic figures in resection specimen. We propose that the increase in mitotic figures in resection specimen and the significant shift towards metaphase figures is not due to a sampling artifact, but reflects ongoing cell cycle activity in the resected tumor tissue due to fixation delay. The dwindling energy supply will eventually arrest tumor cells in metaphase, where they are readily identified by the diagnostic pathologist. Taken together, we suggest that the rapidly fixed biopsy material better represents true tumor biology and should be privileged as predictive marker of putative response to cytotoxic chemotherapy.

  4. Overestimated Oncologic Significance of Lymph Node Metastasis in G1 Nonfunctioning Neuroendocrine Tumor in the Left Side of the Pancreas. (United States)

    Yoo, Young Jin; Yang, Seok Jeong; Hwang, Ho Kyoung; Kang, Chang Moo; Kim, Hogeun; Lee, Woo Jung


    Recent studies have expounded on the oncologic significance of lymph node metastasis in nonfunctioning (NF) neuroendocrine tumors (NETs) of the pancreas and suggest regional lymph node dissection for treating pancreatic NET. We tested this recommendation in NF pancreatic NET-G1, as these tumors are generally small and suitable for function-preserving minimally invasive pancreatectomy.From January 2005 to December 2014, medical records of patients who underwent pancreatectomy for pathologically confirmed NF NET-G1 of the left side of the pancreas were retrospectively reviewed. Oncologic outcomes were compared between limited pancreatectomy and distal pancreatosplenectomy.Thirty-five patients (14 males and 21 females) with a mean age of 55.9 ± 11.4 years were enrolled in this study. Six patients (17.1%) underwent distal pancreatosplenectomy. Limited pancreatectomies comprised 15 spleen-preserving distal pancreatectomies (42.8%), 10 enucleations (28.6%), and 4 central pancreatectomies (11.4%). Lymph node metastasis was not found in 6 patients who underwent distal pancreatectomy with a splenectomy; meanwhile, the others were regarded as pNx since no lymph node retrieval was attempted during the limited pancreatectomy. Overall disease-free survival was 36.5 months (95% confidence interval [CI]: 25.9-47.1) and no tumor-related mortality was noted. Minimally invasive pancreatectomy (P = 0.557) and limited pancreatectomy (P = 0.758) showed no adverse impact in treating NF NET-G1 of the left side of the pancreas.The oncologic significance of lymph node metastasis is overestimated in NF NET-G1 of the left side of the pancreas. Routine conventional distal pancreatosplenectomy to retrieve regional lymph nodes may be too excessive in treating NF NET-G1 of the distal pancreas.

  5. A preliminary model to avoid the overestimation of sample size in bioequivalence studies. (United States)

    Ramírez, E; Abraira, V; Guerra, P; Borobia, A M; Duque, B; López, J L; Mosquera, B; Lubomirov, R; Carcas, A J; Frías, J


    Often the only available data in literature for sample size estimations in bioequivalence studies is intersubject variability, which tends to result in overestimation of sample size. In this paper, we proposed a preliminary model of intrasubject variability based on intersubject variability for Cmax and AUC data from randomized, crossovers, bioequivalence (BE) studies. From 93 Cmax and 121 AUC data from test-reference comparisons that fulfilled BE criteria, we calculated intersubject variability for the reference formulation and intrasubject variability from ANOVA. Lineal and exponential models (y=a(1-e-bx)) were fitted weighted by the inverse of the variance, to predict the intrasubject variability based on intersubject variability. To validate the model we calculated the coefficient of cross-validation of data from 30 new BE studies. The models fit very well (R2=0.997 and 0.990 for Cmax and AUC respectively) and the cross-validation correlation were 0.847 for Cmax and 0.572 for AUC. A preliminary model analyses allow us to estimate the intrasubject variability based on intersubject variability for sample size calculation purposes in BE studies. This approximation provides an opportunity for sample size reduction avoiding unnecessary exposure of healthy volunteers. Further modelling studies are desirable to confirm these results especially suggestions of the higher intersubject variability range.

  6. Serious overestimation in quantitative PCR by circular (supercoiled plasmid standard: microalgal pcna as the model gene.

    Directory of Open Access Journals (Sweden)

    Yubo Hou

    Full Text Available Quantitative real-time PCR (qPCR has become a gold standard for the quantification of nucleic acids and microorganism abundances, in which plasmid DNA carrying the target genes are most commonly used as the standard. A recent study showed that supercoiled circular confirmation of DNA appeared to suppress PCR amplification. However, to what extent to which different structural types of DNA (circular versus linear used as the standard may affect the quantification accuracy has not been evaluated. In this study, we quantitatively compared qPCR accuracies based on circular plasmid (mostly in supercoiled form and linear DNA standards (linearized plasmid DNA or PCR amplicons, using proliferating cell nuclear gene (pcna, the ubiquitous eukaryotic gene, in five marine microalgae as a model gene. We observed that PCR using circular plasmids as template gave 2.65-4.38 more of the threshold cycle number than did equimolar linear standards. While the documented genome sequence of the diatom Thalassiosira pseudonana shows a single copy of pcna, qPCR using the circular plasmid as standard yielded an estimate of 7.77 copies of pcna per genome whereas that using the linear standard gave 1.02 copies per genome. We conclude that circular plasmid DNA is unsuitable as a standard, and linear DNA should be used instead, in absolute qPCR. The serious overestimation by the circular plasmid standard is likely due to the undetected lower efficiency of its amplification in the early stage of PCR when the supercoiled plasmid is the dominant template.

  7. Why do models overestimate surface ozone in the Southeast United States? (United States)

    Travis, Katherine R.; Jacob, Daniel J.; Fisher, Jenny A.; Kim, Patrick S.; Marais, Eloise A.; Zhu, Lei; Yu, Karen; Miller, Christopher C.; Yantosca, Robert M.; Sulprizio, Melissa P.; Thompson, Anne M.; Wennberg, Paul O.; Crounse, John D.; St. Clair, Jason M.; Cohen, Ronald C.; Laughner, Joshua L.; Dibb, Jack E.; Hall, Samuel R.; Ullmann, Kirk; Wolfe, Glenn M.; Pollack, Illana B.; Peischl, Jeff; Neuman, Jonathan A.; Zhou, Xianliang


    Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NOx ≡ NO + NO2) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from the SEAC4RS aircraft campaign in August and September 2013, interpreted with the GEOS-Chem chemical transport model at 0.25° × 0.3125° horizontal resolution, to better understand the factors controlling surface ozone in the Southeast US. We find that the National Emission Inventory (NEI) for NOx from the US Environmental Protection Agency (EPA) is too high. This finding is based on SEAC4RS observations of NOx and its oxidation products, surface network observations of nitrate wet deposition fluxes, and OMI satellite observations of tropospheric NO2 columns. Our results indicate that NEI NOx emissions from mobile and industrial sources must be reduced by 30-60 %, dependent on the assumption of the contribution by soil NOx emissions. Upper-tropospheric NO2 from lightning makes a large contribution to satellite observations of tropospheric NO2 that must be accounted for when using these data to estimate surface NOx emissions. We find that only half of isoprene oxidation proceeds by the high-NOx pathway to produce ozone; this fraction is only moderately sensitive to changes in NOx emissions because isoprene and NOx emissions are spatially segregated. GEOS-Chem with reduced NOx emissions provides an unbiased simulation of ozone observations from the aircraft and reproduces the observed ozone production efficiency in the boundary layer as derived from a regression of ozone and NOx oxidation products. However, the model is still biased high by 6 ± 14 ppb relative to observed surface ozone in the Southeast US. Ozonesondes launched during midday hours show a 7 ppb ozone

  8. Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM (United States)

    Zhou, Cheng; Penner, Joyce E.


    Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 27 May 2011 at the southern Great Plains (SGP) measurement site established by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program using a single-column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP in CAM is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near the cloud top, resulting in an overall decrease in LWP. Our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.

  9. Instantaneous-to-daily GPP upscaling schemes based on a coupled photosynthesis-stomatal conductance model: correcting the overestimation of GPP by directly using daily average meteorological inputs. (United States)

    Wang, Fumin; Gonsamo, Alemu; Chen, Jing M; Black, T Andrew; Zhou, Bin


    Daily canopy photosynthesis is usually temporally upscaled from instantaneous (i.e., seconds) photosynthesis rate. The nonlinear response of photosynthesis to meteorological variables makes the temporal scaling a significant challenge. In this study, two temporal upscaling schemes of daily photosynthesis, the integrated daily model (IDM) and the segmented daily model (SDM), are presented by considering the diurnal variations of meteorological variables based on a coupled photosynthesis-stomatal conductance model. The two models, as well as a simple average daily model (SADM) with daily average meteorological inputs, were validated using the tower-derived gross primary production (GPP) to assess their abilities in simulating daily photosynthesis. The results showed IDM closely followed the seasonal trend of the tower-derived GPP with an average RMSE of 1.63 g C m(-2) day(-1), and an average Nash-Sutcliffe model efficiency coefficient (E) of 0.87. SDM performed similarly to IDM in GPP simulation but decreased the computation time by >66%. SADM overestimated daily GPP by about 15% during the growing season compared to IDM. Both IDM and SDM greatly decreased the overestimation by SADM, and improved the simulation of daily GPP by reducing the RMSE by 34 and 30%, respectively. The results indicated that IDM and SDM are useful temporal upscaling approaches, and both are superior to SADM in daily GPP simulation because they take into account the diurnally varying responses of photosynthesis to meteorological variables. SDM is computationally more efficient, and therefore more suitable for long-term and large-scale GPP simulations.

  10. Age-related increase in food spilling by laboratory mice may lead to significant overestimation of actual food consumption: implications for studies on dietary restriction, metabolism, and dose calculations. (United States)

    Starr, Marlene E; Saito, Hiroshi


    It is widely accepted that food consumption in humans declines with advanced age; however, data from mice remain controversial. Based on our previous observation that mice spill a considerable amount of food while eating, we hypothesized that increased food spillage in old mice masks actual food intake. To investigate whether mice exhibit age-associated declines in food consumption, we evaluated the actual food consumption of C57BL/6 mice at various ages by measuring both the amount of food in the food receptacle and the amount dropped to the cage bottom during feeding. We found that old mice dropped significantly more food (36% ± 8%) than young mice (18% ± 5%), which led to overestimations of food consumption, particularly in old mice. Although actual food consumption decreased in very old mice, food intake per body weight did not significantly change. These findings suggest that caution should be taken to accurately quantify food consumption by aged animals.

  11. Did modeling overestimate the transmission potential of pandemic (H1N1-2009? Sample size estimation for post-epidemic seroepidemiological studies.

    Directory of Open Access Journals (Sweden)

    Hiroshi Nishiura

    Full Text Available BACKGROUND: Seroepidemiological studies before and after the epidemic wave of H1N1-2009 are useful for estimating population attack rates with a potential to validate early estimates of the reproduction number, R, in modeling studies. METHODOLOGY/PRINCIPAL FINDINGS: Since the final epidemic size, the proportion of individuals in a population who become infected during an epidemic, is not the result of a binomial sampling process because infection events are not independent of each other, we propose the use of an asymptotic distribution of the final size to compute approximate 95% confidence intervals of the observed final size. This allows the comparison of the observed final sizes against predictions based on the modeling study (R = 1.15, 1.40 and 1.90, which also yields simple formulae for determining sample sizes for future seroepidemiological studies. We examine a total of eleven published seroepidemiological studies of H1N1-2009 that took place after observing the peak incidence in a number of countries. Observed seropositive proportions in six studies appear to be smaller than that predicted from R = 1.40; four of the six studies sampled serum less than one month after the reported peak incidence. The comparison of the observed final sizes against R = 1.15 and 1.90 reveals that all eleven studies appear not to be significantly deviating from the prediction with R = 1.15, but final sizes in nine studies indicate overestimation if the value R = 1.90 is used. CONCLUSIONS: Sample sizes of published seroepidemiological studies were too small to assess the validity of model predictions except when R = 1.90 was used. We recommend the use of the proposed approach in determining the sample size of post-epidemic seroepidemiological studies, calculating the 95% confidence interval of observed final size, and conducting relevant hypothesis testing instead of the use of methods that rely on a binomial proportion.

  12. Publication bias and the limited strength model of self-control: has the evidence for ego depletion been overestimated? (United States)

    Carter, Evan C; McCullough, Michael E


    Few models of self-control have generated as much scientific interest as has the limited strength model. One of the entailments of this model, the depletion effect, is the expectation that acts of self-control will be less effective when they follow prior acts of self-control. Results from a previous meta-analysis concluded that the depletion effect is robust and medium in magnitude (d = 0.62). However, when we applied methods for estimating and correcting for small-study effects (such as publication bias) to the data from this previous meta-analysis effort, we found very strong signals of publication bias, along with an indication that the depletion effect is actually no different from zero. We conclude that until greater certainty about the size of the depletion effect can be established, circumspection about the existence of this phenomenon is warranted, and that rather than elaborating on the model, research efforts should focus on establishing whether the basic effect exists. We argue that the evidence for the depletion effect is a useful case study for illustrating the dangers of small-study effects as well as some of the possible tools for mitigating their influence in psychological science.

  13. Reductions in blood lead overestimate reductions in brain lead following repeated succimer regimens in a rodent model of childhood lead exposure. (United States)

    Stangle, Diane E; Strawderman, Myla S; Smith, Donald; Kuypers, Mareike; Strupp, Barbara J


    Although many studies have demonstrated the efficacy of succimer chelation in reducing blood and brain lead levels, the relative efficacy of the drug in the two tissues is less well understood. This issue is important because blood lead levels after chelation are used clinically to estimate reductions in the brain, the most critical organ in considering lead-induced neurotoxicity. The present study was designed to further investigate this issue, using multiple chelation regimens. Long-Evans rats were exposed to one of three lead exposure regimens from birth until postnatal day 40, followed by treatment with succimer (one or two 3-week regimens) or vehicle. The results indicated that one succimer regimen was significantly superior to vehicle treatment in lowering lead levels in both blood and brain across the entire 8-week follow-up period. Similarly, a second succimer regimen offered significant additional benefit relative to one regimen for both blood and brain across the 4-week follow-up period. However, several findings revealed that succimer-induced reductions in brain lead lagged behind reductions in blood lead and were generally smaller in magnitude. Furthermore, a rebound was detected in blood, but not brain, lead levels after both succimer regimens. Given the results of this study, we urge caution in using blood lead as a surrogate for brain lead levels, particularly during and immediately after chelation treatment when reductions in blood lead levels overestimate reductions in brain lead levels. The present results suggest that, in clinical use, succimer treatment may need to extend beyond the point at which blood lead levels have dropped to an "acceptable" target value in order to effectively reduce brain lead levels and minimize neurotoxicity.

  14. The risk of intraarticular injections are overestimated

    DEFF Research Database (Denmark)

    Asmussen, Rikke; Just, Søren Andreas; Jensen Hansen, Inger Marie

    The risk of intraarticular injections are overestimated. Volume 73, Annals of the Rheumatic Diseases, the EULAR Journal,, June 2014 volume 73, supplement 2, p. 286-87......The risk of intraarticular injections are overestimated. Volume 73, Annals of the Rheumatic Diseases, the EULAR Journal,, June 2014 volume 73, supplement 2, p. 286-87...

  15. [An overestimated technician - Leonardo da Vinci]. (United States)

    Szabadvary, F

    The reasons are discussed why Leonardo da Vinci is being overestimated as engineer and inventor, although the majority of his drawings concerning engineering are not beyond the level of contemporary engineering knowledge and he never attempted to carry out those which would have been novel in fact.

  16. Nasal pulse oximetry overestimates oxygen saturation

    DEFF Research Database (Denmark)

    Rosenberg, J; Pedersen, M H


    Ten surgical patients were monitored with nasal and finger pulse oximetry (Nellcor N-200) for five study periods with alternating mouth and nasal breathing and switching of cables and sensors. Nasal pulse oximetry was found to overestimate arterial oxygen saturation by 4.7 (SD 1.4%) (bias...

  17. Modelling vocal anatomy's significant effect on speech

    NARCIS (Netherlands)

    de Boer, B.


    This paper investigates the effect of larynx position on the articulatory abilities of a humanlike vocal tract. Previous work has investigated models that were built to resemble the anatomy of existing species or fossil ancestors. This has led to conflicting conclusions about the relation between

  18. Risk of overestimation of urinary cadmium concentrations: interference from molybdenum

    Directory of Open Access Journals (Sweden)

    Cañas A.I.


    Full Text Available We show here that the selection of analytical method is critical when measuring low levels of cadmium in human urine. Cadmium is today usually analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS, which has a higher sensitivity than Atomic Absorption Spectroscopy (AAS. ICP-MS cadmium measurements show interference from tin (114Sn and molybdenum oxides, which can result in an overestimation of cadmium levels. The 114Sn interference is stable and can be mathematically corrected. Molybdenum concentrations in urine are variable and different from individual to individual. We have estimated the degree of error which molybdenum interference introduces in the measurement of cadmium in urine by conventional ICP-MS. 268 urine samples from mothers and their children were measured. Removal of the molybdenum oxide interference (DRC-ICP-MS method reduced urinary cadmium concentrations significantly (47.8%. The urinary molybdenum concentration in children was higher than in their mothers, resulting in greater overestimation. Our results clearly show that the DRC method is essential for reliable measurements of urinary cadmium concentrations, particularly in children. Furthermore, care should be taken when comparing Human Biomonitoring data for cadmium in urine and attention should be paid to which analytical method has been used (e.g. AAS and ICP-Ms, and especially if the measurements have been corrected for molybdenum interference.

  19. Is premating isolation in Drosophila overestimated due to uncontrolled factors?

    Indian Academy of Sciences (India)

    Pelayo Casares; Rafael Piñeiro; Maria C. Carracedo


    Sexual isolation in Drosophila is typically measured by multiple-choice mating tests. While many environmental variables during such tests are controlled by the researcher, there are some factors that are usually uncontrolled. We demonstrate, using Drosophila melanogaster and D. pseudoobscura flies, that the temperature of rearing, preadult density, and level of consanguinity, can all produce differences in mating propensity between genetically equivalent flies. These differences in mating propensity, in turn, can give rise to statistically significant results in multiple-choice mating tests, leading to positive isolation values and the artifactual inference of sexual isolation between populations. This fact agrees with a nonrandom excess of significant positive tests found in a review of the literature of Drosophila intraspecific mating choice. An overestimate of true cases of sexual isolation in Drosophila in the literature can, therefore, not be ruled out.

  20. Is paediatric trauma severity overestimated at triage?

    DEFF Research Database (Denmark)

    DO, H Q; Hesselfeldt, R; Steinmetz, J


    BACKGROUND: Severe paediatric trauma is rare, and pre-hospital and local hospital personnel experience with injured children is often limited. We hypothesised that a higher proportion of paediatric trauma victims were taken to the regional trauma centre (TC). METHODS: This is an observational...... follow-up study that involves one level I TC and seven local hospitals. We included paediatric (trauma patients with a driving distance to the TC > 30 minutes. The primary end-point was the proportion of trauma patients arriving in the TC. RESULTS: We included 1934...... trauma patients, 238 children and 1696 adults. A total of 33/238 children (13.9%) vs. 304/1696 adults (17.9%) were transported to the TC post-injury (P = 0.14). Among these, children were significantly less injured than adults [median Injury Severity Score (ISS) 9 vs. 14, P 

  1. Overestimation of the effect size in group sequential trials. (United States)

    Zhang, Jenny J; Blumenthal, Gideon M; He, Kun; Tang, Shenghui; Cortazar, Patricia; Sridhara, Rajeshwari


    Group sequential designs (GSD), which provide for interim monitoring of efficacy data and allow potential early trial termination while preserving the type I error rate, have become commonplace in oncology clinical trials. Although ethically appealing, GSDs tend to overestimate the true treatment effect size at early interim analyses. Overestimation of the treatment effect may exaggerate the benefit of a drug and provide imprecise information for physicians and their patients about a drug's true effect. The cause and effect of such a phenomenon are generally not well understood by many in clinical trial practice. In this article, we provide a graphical explanation for why the phenomenon of overestimation in GSDs occurs. The potential overestimation of the magnitude of the treatment effect is of particular concern in oncology, in which the more subjective endpoint of progression-free survival has increasingly been adopted as the primary endpoint in pivotal phase III trials. ©2012 AACR.

  2. Ammonium sulphate precipitation overestimates titres of anti-peptide antisera. (United States)

    Roth, B; Barkas, T


    Precipitation by 50% final saturation of ammonium sulphate, a method commonly used to estimate titres and affinity constants of antibodies, was found consistently to overestimate the titre of anti-peptide antisera when compared with other antibody precipitants. The effect could not be attributed to non-IgG fractions, and similar overestimations were found when pure IgG was used. We suggest that the lower values represent a more physiologically relevant estimation.

  3. Quartz red TL SAR equivalent dose overestimation for Chinese loess

    DEFF Research Database (Denmark)

    Lai, Z.P.; Murray, A.S.; Bailey, R.M.


    For the red TL of quartz extracted from Chinese loess, the single-aliquot regenerative-dose (SAR) procedure overestimates the known laboratory doses in dose recovery test. The overestimation is the result of the first heating during the measurement of natural TL signal causing a sensitivity...... of red TL, which is found to be more than 100 Gy. (c) 2005 Elsevier Ltd. All rights reserved....

  4. Overestimation of Knowledge about Word Meanings: The "Misplaced Meaning" Effect (United States)

    Kominsky, Jonathan F.; Keil, Frank C.


    Children and adults may not realize how much they depend on external sources in understanding word meanings. Four experiments investigated the existence and developmental course of a "Misplaced Meaning" (MM) effect, wherein children and adults overestimate their knowledge about the meanings of various words by underestimating how much…

  5. A Study on Overestimating a Given Fraction Defective by an Imperfect Inspector

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    Moon Hee Yang


    Full Text Available It has been believed that even an imperfect inspector with nonzero inspection errors could either overestimate or underestimate a given FD (fraction defective with a 50 : 50 chance. What happens to the existing inspection plans, if an imperfect inspector overestimates a known FD, when it is very low? We deal with this fundamental question, by constructing four mathematical models, under the assumptions that an infinite sequence of items with a known FD is given to an imperfect inspector with nonzero inspection errors, which can be constant and/or randomly distributed with a uniform distribution. We derive four analytical formulas for computing the probability of overestimation (POE and prove that an imperfect inspector overestimates a given FD with more than 50%, if the FD is less than a value termed as a critical FD. Our mathematical proof indicates that the POE approaches one when FD approaches zero under our assumptions. Hence, if a given FD is very low, commercial inspection plans should be revised with the POE concept in the near future, for the fairness of commercial trades.

  6. Reappraisal mitigates overestimation of remembered pain in anxious individuals. (United States)

    Hovasapian, Arpine; Levine, Linda J


    Anxiety sensitivity, a trait characterised by fear of anxiety-related body sensations, has been linked to heightened attention to pain, appraising body sensations as threatening, and remembering threat-related information. We assessed whether individuals with greater anxiety sensitivity overestimate in remembering pain. We also assessed whether emotion regulation strategies that direct attention away from pain (distraction), or alter appraisals of pain (reappraisal), alleviate memory bias. Participants (N = 137) were randomly assigned to one of two emotion regulation conditions or to a control condition before taking part in a cold pressor task. Greater anxiety sensitivity was associated with overestimation in remembering pain. Engaging in reappraisal mitigated this memory bias but engaging in distraction did not. This is the first study to examine the relations among anxiety sensitivity, emotion regulation and memory for pain. The findings suggest that health-care practitioners can encourage reappraisal to promote more positive memories of procedural pain, particularly in patients high in anxiety sensitivity.

  7. Parameter and Process Significance in Mechanistic Modeling of Cellulose Hydrolysis (United States)

    Rotter, B.; Barry, A.; Gerhard, J.; Small, J.; Tahar, B.


    The rate of cellulose hydrolysis, and of associated microbial processes, is important in determining the stability of landfills and their potential impact on the environment, as well as associated time scales. To permit further exploration in this field, a process-based model of cellulose hydrolysis was developed. The model, which is relevant to both landfill and anaerobic digesters, includes a novel approach to biomass transfer between a cellulose-bound biofilm and biomass in the surrounding liquid. Model results highlight the significance of the bacterial colonization of cellulose particles by attachment through contact in solution. Simulations revealed that enhanced colonization, and therefore cellulose degradation, was associated with reduced cellulose particle size, higher biomass populations in solution, and increased cellulose-binding ability of the biomass. A sensitivity analysis of the system parameters revealed different sensitivities to model parameters for a typical landfill scenario versus that for an anaerobic digester. The results indicate that relative surface area of cellulose and proximity of hydrolyzing bacteria are key factors determining the cellulose degradation rate.

  8. The coexistence of overestimation and underweighting of rare events and the contingent recency effect

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    Greg Barron


    Full Text Available Previous research demonstrates overestimation of rare events in judgment tasks, and underweighting of rare events in decisions from experience. The current paper presents three laboratory experiments and a field study that explore this pattern. The results suggest that the overestimation and underweighting pattern can emerge in parallel. Part of the difference between the two tendencies can be explained as a product of a contingent recency effect: Although the estimations reflect negative recency, choice behavior reflects positive recency. A similar pattern is observed in the field study: Immediately following an aversive rare-event (i.e., a suicide bombing people believe the risk decreases (negative recency but at the same time exhibit more cautious behavior (positive recency. The rest of the difference is consistent with two well established mechanisms: judgment error and the use of small samples in choice. Implications for the two-stage choice model are discussed.

  9. So close, and yet so far: does collectivism foster transparency overestimation? (United States)

    Vorauer, Jacquie D; Cameron, Jessica J


    The present research demonstrated that horizontal collectivism (HC), the tendency to emphasize social bonds and interdependence, is associated with overestimating the extent to which one's preferences, feelings, and behavioral inclinations are transparent to close others. The link between HC and felt transparency was mediated by self-other merging but was not significantly mediated by perceived similarity, behavioral closeness, or metaperception positivity. Evidence of a causal connection was obtained in an experiment where individuals for whom interdependence was primed exhibited greater transparency overestimation than did those for whom it was not. Additional results indicated that higher HC is associated with greater confidence but not greater accuracy in judgments about a friend. The authors argue that other perspective-taking deficits involving overuse of the self in judgments of others should also be exacerbated by the self-other merging that is associated with HC.

  10. Overestimation of heterotrophic bacteria in the Sargasso Sea: direct evidence by flow and imaging cytometry (United States)

    Sieracki, Michael E.; Haugen, Elin M.; Cucci, Terry L.


    Accurate measurements of bacterial biomass in the ocean are needed for modeling marine microbial food webs and global biogeochemical cycling. We present direct evidence that previous estimates of heterotrophic bacteria biomass in the oligotrophic ocean are confounded by the presence of the abundant photosynthetic procaryote, Prochlorococcus. The chlorophyll autofluorescence of these photosynthetic bacterial cells is very faint and fades rapidly under epifluorescence microscopy. Detection and enumeration of these cells thus far has almost exclusively been by flow cytometry. Using a cooled, charge-coupled device (CCD) camera we were able to image these cells for direct biovolume measurements. A double-exposed image of DAPI-stained Prochlorococcus cells shows that they are indistinguishable from heterotrophic bacteria in standard slide preparations. At two Sargasso Sea stations Prochlorococcus could cause an overestimation of surface (top 150 m) integrated heterotrophic bacterial biovolume (biomass) of 18 and 22% determined by standard microscope methods. At the subsurface chlorophyll maximum Prochlorococcus was 33 and 43% of the heterotrophic bacterial biovolume (biomass) at these stations. Prochlorococcus cell size increased from 0.05 μm 3 in the surface mixed layer to about 0.2 μm 3 below 100 m, confirming previous interpretations of flow cytometric light scatter measurements. Shifting biomass from the heterotrophic bacteria pool to the primary producer compartment has significant implications for ecosystem structure and trophic transfer in marine food webs.

  11. Is flow velocity a significant parameter in flood damage modelling?

    Directory of Open Access Journals (Sweden)

    H. Kreibich


    Full Text Available Flow velocity is generally presumed to influence flood damage. However, this influence is hardly quantified and virtually no damage models take it into account. Therefore, the influences of flow velocity, water depth and combinations of these two impact parameters on various types of flood damage were investigated in five communities affected by the Elbe catchment flood in Germany in 2002. 2-D hydraulic models with high to medium spatial resolutions were used to calculate the impact parameters at the sites in which damage occurred. A significant influence of flow velocity on structural damage, particularly on roads, could be shown in contrast to a minor influence on monetary losses and business interruption. Forecasts of structural damage to road infrastructure should be based on flow velocity alone. The energy head is suggested as a suitable flood impact parameter for reliable forecasting of structural damage to residential buildings above a critical impact level of 2 m of energy head or water depth. However, general consideration of flow velocity in flood damage modelling, particularly for estimating monetary loss, cannot be recommended.

  12. Multiresolution wavelet-ANN model for significant wave height forecasting.

    Digital Repository Service at National Institute of Oceanography (India)

    Deka, P.C.; Mandal, S.; Prahlada, R.

    Hybrid wavelet artificial neural network (WLNN) has been applied in the present study to forecast significant wave heights (Hs). Here Discrete Wavelet Transformation is used to preprocess the time series data (Hs) prior to Artificial Neural Network...

  13. Ignoring detailed fast-changing dynamics of land use overestimates regional terrestrial carbon sequestration

    Directory of Open Access Journals (Sweden)

    S. Zhao


    Full Text Available Land use change is critical in determining the distribution, magnitude and mechanisms of terrestrial carbon budgets at the local to global scales. To date, almost all regional to global carbon cycle studies are driven by a static land use map or land use change statistics with decadal time intervals. The biases in quantifying carbon exchange between the terrestrial ecosystems and the atmosphere caused by using such land use change information have not been investigated. Here, we used the General Ensemble biogeochemical Modeling System (GEMS, along with consistent and spatially explicit land use change scenarios with different intervals (1 yr, 5 yrs, 10 yrs and static, respectively, to evaluate the impacts of land use change data frequency on estimating regional carbon sequestration in the southeastern United States. Our results indicate that ignoring the detailed fast-changing dynamics of land use can lead to a significant overestimation of carbon uptake by the terrestrial ecosystem. Regional carbon sequestration increased from 0.27 to 0.69, 0.80 and 0.97 Mg C ha−1 yr−1 when land use change data frequency shifting from 1 year to 5 years, 10 years interval and static land use information, respectively. Carbon removal by forest harvesting and prolonged cumulative impacts of historical land use change on carbon cycle accounted for the differences in carbon sequestration between static and dynamic land use change scenarios. The results suggest that it is critical to incorporate the detailed dynamics of land use change into local to global carbon cycle studies. Otherwise, it is impossible to accurately quantify the geographic distributions, magnitudes, and mechanisms of terrestrial carbon sequestration at local to global scales.

  14. Scalar Dark Matter Models with Significant Internal Bremsstrahlung

    CERN Document Server

    Giacchino, Federica; Tytgat, Michel H G


    There has been interest recently on particle physics models that may give rise to sharp gamma ray spectral features from dark matter annihilation. Because dark matter is supposed to be electrically neutral, it is challenging to build weakly interacting massive particle models that may accommodate both a large cross section into gamma rays at, say, the Galactic center, and the right dark matter abundance. In this work, we consider the gamma ray signatures of a class of scalar dark matter models that interact with Standard Model dominantly through heavy vector-like fermions (the vector-like portal). We focus on a real scalar singlet S annihilating into lepton-antilepton pairs. Because this two-body final-state annihilation channel is d-wave suppressed in the chiral limit, we show that virtual internal bremsstrahlung emission of a gamma ray gives a large correction, both today and at the time of freeze-out. For the sake of comparison, we confront this scenario to the familiar case of a Majorana singlet annihilat...

  15. The significance of genetics in pathophysiologic models of premature birth. (United States)

    Uberos, Jose


    Prematurity is a major health problem in all countries, especially in certain ethic groups and increasing recurrence imply the influence of genetic factors. Published genetic polymorphisms are identified in relation to the 4 pathophysiological models of prematurity described: Chorioamniotic-decidual inflammation, premature contraction pathway, decidual haemorrhage and susceptibility to environmental toxins. 240 articles are identified, 52 articles are excluded because they are not original, not written in English or duplicated. From them 125 articles were included in qualitative analysis This review aims to update recent knowledge about genes associated with premature birth.

  16. Overestimation of canine albumin concentration with the bromcresol green method in heparinized plasma samples. (United States)

    Stokol, Tracy; Tarrant, Jacqueline M.; Scarlett, Janet M.


    Albumin concentrations are routinely measured in dogs with bromcresol green (BCG)-binding assays on automated chemistry analyzers. Several variables affect this assay, including the length of reaction time, sample type, and lack of specificity of BCG for albumin. We observed that albumin concentrations measured with BCG appeared higher in heparinized plasma samples in sick dogs. The objective of this study was to determine the effect of anticoagulant and assay procedure on BCG albumin concentrations in clinically ill dogs. We hypothesized that albumin concentrations would be overestimated in heparinized plasma compared with serum because of the combination of heparin and fibrinogen. Furthermore, we hypothesized that the overestimation would be influenced by assay parameters. Blood was collected from 32 clinically ill dogs into tubes containing heparin, citrate, or no anticoagulant. Citrate was chosen to assess the effect of fibrinogen in the absence of heparin. Albumin concentration was measured in all 3 sample types from each dog using 2 different BCG procedures on an automated chemistry analyzer. The BCG procedures (standard and modified) differed in the wavelengths used for absorbance readings (standard, 600/700; modified, 570/505) and the time point at which absorbance was measured (standard, 100 seconds; modified, 40 seconds). In addition, the modified method incorporated a sample blank. Globulin fractions, fibrinogen concentration, and indices of lipemia, hemolysis, and icterus were evaluated for their contribution to the overestimation of albumin concentration in heparinized plasma compared with serum samples. Albumin concentrations were significantly higher (P Overestimation was evident only with the standard BCG procedure. Multiple linear regression analysis indicated that fibrinogen was largely responsible for the higher

  17. Oil cracking to gases: Kinetic modeling and geological significance

    Institute of Scientific and Technical Information of China (English)

    TIAN Hui; WANG Zhaoming; XIAO Zhongyao; LI Xianqing; XIAO Xianming


    ATriassic oil sample from LN14 of Tarim Basin was pyrolyzed using the sealed gold tubes at 200-620℃ under a constant pressure of 50 MPa.The gaseous and residual soluble hydrocarbons were analyzed. The results show that the cracking of oil to gas can be divided into two distinct stages: the primary generation of total C1-5 gases from liquid oil characterized by the dominance of C2-5 hydrocarbons and the secondary or further cracking of C2-5gases to methane and carbon-rich matters leading to the progressive dryness of gases. Based on the experimental data, the kinetic parameters were determined for the primary generation and secondary cracking of oil cracking gases and extrapolated to geological conditions to predict the thermal stability and cracking extent of crude oil. Finally, an evolution model for the thermal destruction of crude oil was proposed and its implications to the migration and accumulation of oil cracking gases were discussed.

  18. Accuracy of pitch matching significantly improved by live voice model. (United States)

    Granot, Roni Y; Israel-Kolatt, Rona; Gilboa, Avi; Kolatt, Tsafrir


    Singing is, undoubtedly, the most fundamental expression of our musical capacity, yet an estimated 10-15% of Western population sings "out-of-tune (OOT)." Previous research in children and adults suggests, albeit inconsistently, that imitating a human voice can improve pitch matching. In the present study, we focus on the potentially beneficial effects of the human voice and especially the live human voice. Eighteen participants varying in their singing abilities were required to imitate in singing a set of nine ascending and descending intervals presented to them in five different randomized blocked conditions: live piano, recorded piano, live voice using optimal voice production, recorded voice using optimal voice production, and recorded voice using artificial forced voice production. Pitch and interval matching in singing were much more accurate when participants repeated sung intervals as compared with intervals played to them on the piano. The advantage of the vocal over the piano stimuli was robust and emerged clearly regardless of whether piano tones were played live and in full view or were presented via recording. Live vocal stimuli elicited higher accuracy than recorded vocal stimuli, especially when the recorded vocal stimuli were produced in a forced vocal production. Remarkably, even those who would be considered OOT singers on the basis of their performance when repeating piano tones were able to pitch match live vocal sounds, with deviations well within the range of what is considered accurate singing (M=46.0, standard deviation=39.2 cents). In fact, those participants who were most OOT gained the most from the live voice model. Results are discussed in light of the dual auditory-motor encoding of pitch analogous to that found in speech. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  19. The Overestimation Phenomenon in a Skill-Based Gaming Context: The Case of March Madness Pools. (United States)

    Kwak, Dae Hee


    Over 100 million people are estimated to take part in the NCAA Men's Basketball Tournament Championship bracket contests. However, relatively little is known about consumer behavior in skill-based gaming situations (e.g., sports betting). In two studies, we investigated the overestimation phenomenon in the "March Madness" context. In Study 1 (N = 81), we found that individuals who were allowed to make their own predictions were significantly more optimistic about their performance than individuals who did not make their own selections. In Study 2 (N = 197), all subjects participated in a mock competitive bracket pool. In line with the illusion of control theory, results showed that higher self-ratings of probability of winning significantly increased maximum willingness to wager but did not improve actual performance. Lastly, perceptions of high probability of winning significantly contributed to consumers' enjoyment and willingness to participate in a bracket pool in the future.

  20. Coronal 2D MR cholangiography overestimates the length of the right hepatic duct in liver transplantation donors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bohyun [University of Ulsan College of Medicine, Department of Radiology, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul (Korea, Republic of); Ajou University School of Medicine, Department of Radiology, Ajou University Medical Center, Suwon (Korea, Republic of); Kim, Kyoung Won; Kim, So Yeon; Park, So Hyun [University of Ulsan College of Medicine, Department of Radiology, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul (Korea, Republic of); Lee, Jeongjin [Soongsil University, School of Computer Science and Engineering, Seoul (Korea, Republic of); Song, Gi Won; Jung, Dong-Hwan; Ha, Tae-Yong; Lee, Sung Gyu [University of Ulsan College of Medicine, Department of Surgery, Division of Hepatobiliary and Liver Transplantation Surgery, Asan Medical Center, Seoul (Korea, Republic of)


    To compare the length of the right hepatic duct (RHD) measured on rotatory coronal 2D MR cholangiography (MRC), rotatory axial 2D MRC, and reconstructed 3D MRC. Sixty-seven donors underwent coronal and axial 2D projection MRC and 3D MRC. RHD length was measured and categorized as ultrashort (≤1 mm), short (>1-14 mm), and long (>14 mm). The measured length, frequency of overestimation, and the degree of underestimation between two 2D MRC sets were compared to 3D MRC. The length of the RHD from 3D MRC, coronal 2D MRC, and axial 2D MRC showed significant difference (p < 0.05). RHD was frequently overestimated on the coronal than on axial 2D MRC (61.2 % vs. 9 %; p <.0001). On coronal 2D MRC, four (6 %) with short RHD and one (1.5 %) with ultrashort RHD were over-categorized as long RHD. On axial 2D MRC, overestimation was mostly <1 mm (83.3 %), none exceeding 3 mm or over-categorized. The degree of underestimation between the two projection planes was comparable. Coronal 2D MRC overestimates the RHD in liver donors. We suggest adding axial 2D MRC to conventional coronal 2D MRC in the preoperative workup protocol for living liver donors to avoid unexpected confrontation with multiple ductal openings when harvesting the graft. (orig.)

  1. Influential factors affecting age-related self-overestimation of step-over ability: focusing on frequency of going outdoors and executive function. (United States)

    Sakurai, Ryota; Fujiwara, Yoshinori; Sakuma, Naoko; Suzuki, Hiroyuki; Ishihara, Masami; Higuchi, Takahiro; Imanaka, Kuniyasu


    Self-overestimation of step-over ability among older adults may result in a potential fall risk. However, the behavioral causal factor(s) of older adults' self-overestimation is unclear. We examined whether older adults' overestimation of step-over ability was mediated by an inactive lifestyle and/or poor executive function. A sample of 194 community-dwelling older adults was assigned to either a high (HG, once a day or more) or low (LG, every 2-3 days or less) frequency of going outdoors group. Executive function was determined by the Trail-Making Test (TMT). Both the HG and LG participants performed Step-Over Tests (SOT) in two ways: self-estimation of step-over ability and the actual step-over task. During the self-estimation task, participants observed the horizontal bar at a distance of 7 m and predicted the self-estimated maximum height (EH) of successful SOT trials. The motor task was then performed, determining the actual maximum height (AH) of successful trials. A total of 36.1% of LG participants failed to successfully perform SOT trials at their EH (i.e., overestimation), whereas only 11.3% of HG participants failed. A multiple linear regression analysis showed that SOT overestimation was associated with an inactive lifestyle (low frequency of going outdoors) but not with executive function. Analyses of fall experience showed that both executive function and lifestyle significantly correlated with SOT overestimation among fallers, whereas only lifestyle was significantly correlated among non-fallers. Our results suggest that an inactive lifestyle is a possible correlate of SOT overestimation among older adults, while executive function further influenced overestimation only among fallers. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Overestimating climate warming-induced methane gas escape from the seafloor by neglecting multiphase flow dynamics (United States)

    Stranne, C.; O'Regan, M.; Jakobsson, M.


    Continental margins host large quantities of methane stored partly as hydrates in sediments. Release of methane through hydrate dissociation is implicated as a possible feedback mechanism to climate change. Large-scale estimates of future warming-induced methane release are commonly based on a hydrate stability approach that omits dynamic processes. Here we use the multiphase flow model TOUGH + hydrate (T + H) to quantitatively investigate how dynamic processes affect dissociation rates and methane release. The simulations involve shallow, 20-100 m thick hydrate deposits, forced by a bottom water temperature increase of 0.03°C yr-1 over 100 years. We show that on a centennial time scale, the hydrate stability approach can overestimate gas escape quantities by orders of magnitude. Our results indicate a time lag of > 40 years between the onset of warming and gas escape, meaning that recent climate warming may soon be manifested as widespread gas seepages along the world's continental margins.

  3. People overestimate their willingness to reject potential romantic partners by overlooking their concern for other people. (United States)

    Joel, Samantha; Teper, Rimma; MacDonald, Geoff


    Mate preferences often fail to correspond with actual mate choices. We present a novel explanation for this phenomenon: People overestimate their willingness to reject unsuitable romantic partners. In two studies, single people were given the opportunity to accept or decline advances from potential dates who were physically unattractive (Study 1) or incompatible with their dating preferences (Study 2). We found that participants were significantly less willing to reject these unsuitable potential dates when they believed the situation to be real rather than hypothetical. This effect was partially explained by other-focused motives: Participants for whom the scenario was hypothetical anticipated less motivation to avoid hurting the potential date's feelings than participants actually felt when they believed the situation to be real. Thus, other-focused motives appear to exert an influence on mate choice that has been overlooked by researchers and laypeople alike.

  4. Gun Carrying by High School Students in Boston, MA: Does Overestimation of Peer Gun Carrying Matter? (United States)

    Hemenway, David; Vriniotis, Mary; Johnson, Renee M.; Miller, Matthew; Azrael, Deborah


    This paper investigates: (1) whether high school students overestimate gun carrying by their peers, and (2) whether those students who overestimate peer gun carrying are more likely to carry firearms. Data come from a randomly sampled survey conducted in 2008 of over 1700 high school students in Boston, MA. Over 5% of students reported carrying a…

  5. Gun Carrying by High School Students in Boston, MA: Does Overestimation of Peer Gun Carrying Matter? (United States)

    Hemenway, David; Vriniotis, Mary; Johnson, Renee M.; Miller, Matthew; Azrael, Deborah


    This paper investigates: (1) whether high school students overestimate gun carrying by their peers, and (2) whether those students who overestimate peer gun carrying are more likely to carry firearms. Data come from a randomly sampled survey conducted in 2008 of over 1700 high school students in Boston, MA. Over 5% of students reported carrying a…

  6. Americans Still Overestimate Social Class Mobility: A Pre-Registered Self-Replication

    Directory of Open Access Journals (Sweden)

    Michael W. Kraus


    Full Text Available Kraus and Tan (2015 hypothesized that Americans tend to overestimate social class mobility in society, and do so because they seek to protect the self. This paper reports a pre-registered exact replication of Study 3 from this original paper and finds, consistent with the original study, that Americans substantially overestimate social class mobility, that people provide greater overestimates when made while thinking of similar others, and that high perceived social class is related to greater overestimates. The current results provide additional evidence consistent with the idea that people overestimate class mobility to protect their beliefs in the promise of equality of opportunity. Discussion considers the utility of pre-registered self-replications as one tool for encouraging replication efforts and assessing the robustness of effect sizes.

  7. The influence of drug kinetics in blood on the calculation of oral bioavailability in linear pharmacokinetics: the traditional equation may considerably overestimate the true value. (United States)

    Berezhkovskiy, Leonid M


    A common calculation of oral bioavailability is based on the comparison of the areas under the concentration-time curves after intravenous and oral drug administration. It does not take into account that after the oral dosing a drug enters the systemic circulation in different states, that is, as free fraction, protein bound and partitioned into blood cells, and plasma lipids, while after intravenous input it is introduced into the systemic circulation only as a free fraction. Consideration of this difference leads to a novel equation for the oral bioavailability. In general, the traditional calculation overestimates the oral bioavailability. For a widely applied model of a linear pharmacokinetic system with central (plasma) drug elimination it is shown that the traditional calculation of the oral bioavailability could substantially overestimate the true value. If the existence of an immediate equilibrium between different drug fractions in blood is assumed, the obtained equation becomes identical to the traditional one. Thus the deviation of oral bioavailability from the value given by a common calculation appears to be a kinetic phenomenon. The difference could be significant for the drugs with the rate constant of elimination from plasma of the same order of magnitude or greater than the dissociation rate constant of drug-protein complexes, or the off-rate constant of partitioning from the blood cells, if the blood concentration profiles were used to calculate the oral bioavailability.

  8. Overestimation of marsh vulnerability to sea level rise (United States)

    Kirwan, Matthew L.; Temmerman, Stijn; Skeehan, Emily E.; Guntenspergen, Glenn R.; Fagherazzi, Sergio


    Coastal marshes are considered to be among the most valuable and vulnerable ecosystems on Earth, where the imminent loss of ecosystem services is a feared consequence of sea level rise. However, we show with a meta-analysis that global measurements of marsh elevation change indicate that marshes are generally building at rates similar to or exceeding historical sea level rise, and that process-based models predict survival under a wide range of future sea level scenarios. We argue that marsh vulnerability tends to be overstated because assessment methods often fail to consider biophysical feedback processes known to accelerate soil building with sea level rise, and the potential for marshes to migrate inland.

  9. Scalenus minimus muscle: overestimated or not? An anatomical study. (United States)

    Natsis, Konstantinos; Totlis, Trifon; Didagelos, Matthaios; Tsakotos, George; Vlassis, Konstantinos; Skandalakis, Panagiotis


    The wide range of scalenus minimus muscle incidence reported in the literature along with the plethora of fibromuscular structures that may appear in the interscalene triangle, having various terminologies, were the reasons to conduct the present study questioning the reported high incidence of this supernumerary scalene muscle. Seventy-three Greek cadavers were dissected and examined for the presence of a scalenus minimus muscle. It was found unilaterally in three of 73 (4.11%) cadavers studied. The literature review, concerning its incidence, revealed a wide range between 7.8 and 71.7 per cent, which cannot be attributed only to racial variation. Thus, there is a matter whether other variations of the scalene muscles are considered as a true scalenus minimus muscle. Recognition of this muscle is important not only for anatomists, but also has clinical significance for the diagnosis of the thoracic outlet syndrome. Surgeons performing scalenectomy and anesthesiologists during interscalene brachial plexus block should keep in mind the anatomical variations of this region.

  10. Do blushing phobics overestimate the undesirable communicative effects of their blushing?

    NARCIS (Netherlands)

    de Jong, PJ; Peters, ML


    Previous research indicated that blushing has socially threatening revealing effects in ambiguous situations. To explain blushing phobics' fearful preoccupation with blushing, we tested the hypothesis that blushing fearful individuals overestimate its revealing effects. High (n = 20) and low (n = 20

  11. Influencing Factors on the Overestimation of Self-Reported Physical Activity: A Cross-Sectional Analysis of Low Back Pain Patients and Healthy Controls

    Directory of Open Access Journals (Sweden)

    Andrea Schaller


    Full Text Available Introduction. The aim of the present study was to determine the closeness of agreement between a self-reported and an objective measure of physical activity in low back pain patients and healthy controls. Beyond, influencing factors on overestimation were identified. Methods. 27 low back pain patients and 53 healthy controls wore an accelerometer (objective measure for seven consecutive days and answered a questionnaire on physical activity (self-report over the same period of time. Differences between self-reported and objective data were tested by Wilcoxon test. Bland-Altman analysis was conducted for describing the closeness of agreement. Linear regression models were calculated to identify the influence of age, sex, and body mass index on the overestimation by self-report. Results. Participants overestimated self-reported moderate activity in average by 42 min/day (p=0.003 and vigorous activity by 39 min/day (p<0.001. Self-reported sedentary time was underestimated by 122 min/day (p<0.001. No individual-related variables influenced the overestimation of physical activity. Low back pain patients were more likely to underestimate sedentary time compared to healthy controls. Discussion. In rehabilitation and health promotion, the application-oriented measurement of physical activity remains a challenge. The present results contradict other studies that had identified an influence of age, sex, and body mass index on the overestimation of physical activity.

  12. Influencing Factors on the Overestimation of Self-Reported Physical Activity: A Cross-Sectional Analysis of Low Back Pain Patients and Healthy Controls. (United States)

    Schaller, Andrea; Rudolf, Kevin; Dejonghe, Lea; Grieben, Christopher; Froboese, Ingo


    Introduction. The aim of the present study was to determine the closeness of agreement between a self-reported and an objective measure of physical activity in low back pain patients and healthy controls. Beyond, influencing factors on overestimation were identified. Methods. 27 low back pain patients and 53 healthy controls wore an accelerometer (objective measure) for seven consecutive days and answered a questionnaire on physical activity (self-report) over the same period of time. Differences between self-reported and objective data were tested by Wilcoxon test. Bland-Altman analysis was conducted for describing the closeness of agreement. Linear regression models were calculated to identify the influence of age, sex, and body mass index on the overestimation by self-report. Results. Participants overestimated self-reported moderate activity in average by 42 min/day (p = 0.003) and vigorous activity by 39 min/day (p < 0.001). Self-reported sedentary time was underestimated by 122 min/day (p < 0.001). No individual-related variables influenced the overestimation of physical activity. Low back pain patients were more likely to underestimate sedentary time compared to healthy controls. Discussion. In rehabilitation and health promotion, the application-oriented measurement of physical activity remains a challenge. The present results contradict other studies that had identified an influence of age, sex, and body mass index on the overestimation of physical activity.

  13. Have GRACE satellites overestimated groundwater depletion in the Northwest India Aquifer? (United States)

    Long, Di; Chen, Xi; Scanlon, Bridget R.; Wada, Yoshihide; Hong, Yang; Singh, Vijay P.; Chen, Yaning; Wang, Cunguang; Han, Zhongying; Yang, Wenting


    The Northwest India Aquifer (NWIA) has been shown to have the highest groundwater depletion (GWD) rate globally, threatening crop production and sustainability of groundwater resources. Gravity Recovery and Climate Experiment (GRACE) satellites have been emerging as a powerful tool to evaluate GWD with ancillary data. Accurate GWD estimation is, however, challenging because of uncertainties in GRACE data processing. We evaluated GWD rates over the NWIA using a variety of approaches, including newly developed constrained forward modeling resulting in a GWD rate of 3.1 ± 0.1 cm/a (or 14 ± 0.4 km3/a) for Jan 2005-Dec 2010, consistent with the GWD rate (2.8 cm/a or 12.3 km3/a) from groundwater-level monitoring data. Published studies (e.g., 4 ± 1 cm/a or 18 ± 4.4 km3/a) may overestimate GWD over this region. This study highlights uncertainties in GWD estimates and the importance of incorporating a priori information to refine spatial patterns of GRACE signals that could be more useful in groundwater resource management and need to be paid more attention in future studies.

  14. The prevalence of maternal F cells in a pregnant population and potential overestimation of foeto-maternal haemorrhage as a consequence.

    LENUS (Irish Health Repository)

    Corcoran, Deirdre


    Acid elution (AE) is used to estimate foeto-maternal haemorrhage (FMH). However AE cannot differentiate between cells containing foetal or adult haemoglobin F (F cells), potentially leading to false positive results or an overestimate of the amount of FMH. The prevalence of F cells in pregnant populations remains poorly characterised. The purpose of this study was to ascertain the incidence of HbF-containing red cells in our pregnant population using anti-HbF-fluorescein isothiocyanate flow cytometry (anti-HbF FC) and to assess whether its presence leads to a significant overestimate of FMH.

  15. Forgetting to Remember Our Experiences: People Overestimate How Much They Will Retrospect About Personal Events. (United States)

    Tully, Stephanie; Meyvis, Tom


    People value experiences in part because of the memories they create. Yet, we find that people systematically overestimate how much they will retrospect about their experiences. This overestimation results from people focusing on their desire to retrospect about experiences, while failing to consider the experience's limited enduring accessibility in memory. Consistent with this view, we find that desirability is a stronger predictor of forecasted retrospection than it is of reported retrospection, resulting in greater overestimation when the desirability of retrospection is higher. Importantly, the desire to retrospect does not change over time. Instead, past experiences become less top-of-mind over time and, as a result, people simply forget to remember. In line with this account, our results show that obtaining physical reminders of an experience reduces the overestimation of retrospection by increasing how much people retrospect, bringing their realized retrospection more in line with their forecasts (and aspirations). We further observe that the extent to which reported retrospection falls short of forecasted retrospection reliably predicts declining satisfaction with an experience over time. Despite this potential negative consequence of retrospection falling short of expectations, we suggest that the initial overestimation itself may in fact be adaptive. This possibility and other potential implications of this work are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Lake Wobegon’s Guns: Overestimating Our Gun-Related Competences

    Directory of Open Access Journals (Sweden)

    Emily Stark


    Full Text Available The Lake Wobegon Effect is a general tendency for people to overestimate their own abilities. In this study, the authors conducted a large, nationally-representative survey of U.S. citizens to test whether Americans overestimate their own gun-relevant personality traits, gun safety knowledge, and ability to use a gun in an emergency. The authors also tested how gun control attitudes, political identification, gender, and gun experience affect self-perceptions. Consistent with prior research on the Lake Wobegon Effect, participants overestimated their gun-related competencies. Conservatives, males, and pro-gun advocates self-enhanced somewhat more than their counterparts but this effect was primarily due to increased gun experience among these participants. These findings are important to policymakers in the area of gun use, because overconfidence in one’s gun-related abilities may lead to a reduced perceived need for gun training.

  17. Illusory ownership of a virtual child body causes overestimation of object sizes and implicit attitude changes. (United States)

    Banakou, Domna; Groten, Raphaela; Slater, Mel


    An illusory sensation of ownership over a surrogate limb or whole body can be induced through specific forms of multisensory stimulation, such as synchronous visuotactile tapping on the hidden real and visible rubber hand in the rubber hand illusion. Such methods have been used to induce ownership over a manikin and a virtual body that substitute the real body, as seen from first-person perspective, through a head-mounted display. However, the perceptual and behavioral consequences of such transformed body ownership have hardly been explored. In Exp. 1, immersive virtual reality was used to embody 30 adults as a 4-y-old child (condition C), and as an adult body scaled to the same height as the child (condition A), experienced from the first-person perspective, and with virtual and real body movements synchronized. The result was a strong body-ownership illusion equally for C and A. Moreover there was an overestimation of the sizes of objects compared with a nonembodied baseline, which was significantly greater for C compared with A. An implicit association test showed that C resulted in significantly faster reaction times for the classification of self with child-like compared with adult-like attributes. Exp. 2 with an additional 16 participants extinguished the ownership illusion by using visuomotor asynchrony, with all else equal. The size-estimation and implicit association test differences between C and A were also extinguished. We conclude that there are perceptual and probably behavioral correlates of body-ownership illusions that occur as a function of the type of body in which embodiment occurs.

  18. Significance of radiation models in investigating the flow phenomena around a Jovian entry body (United States)

    Tiwari, S. N.; Subramanian, S. V.


    Formulation is presented to demonstrate the significance of a simplified radiation model in investigating the flow-phenomena in the viscous radiating shock layer of a Jovian entry body. For this, a nongray absorption model for hydrogen-helium gas is developed which consists of 30 steps over the spectral range of 0-20 eV. By employing this model results were obtained for temperature, pressure, density, and radiative flux in the shock layer and along the body surface. These are compared with results of two sophisticated radiative transport models available in the literature. Use of the present radiation model results in significant reduction in computational time. Results of this model are found to be in general agreement with results of other models. It is concluded that use of the present model is justified in investigating the flow phenomena around a Jovian entry body because it is relatively simple, computationally fast, and yields fairly accurate results.

  19. Quasi-degenerate Neutrino mass models and their significance: A model independent investigation

    CERN Document Server

    Roy, S


    The prediction of possible ordering of neutrino masses relies mostly on the model selected. Alienating the $\\mu-\\tau$ interchange symmetry from discrete flavour symmetry based models, turns the neutrino mass matrix less predictive. But this inspires one to seek the answer from other phenomenological frameworks. We need a proper parametrization of the neutrino mass matrices concerning individual hierarchies. In the present work, we attempt to study the six different cases of Quasi-degenerate (QDN) neutrino models. The related mass matrices, $m_{LL}^{\

  20. Blushing-fearful individuals overestimate the costs and probability of their blushing

    NARCIS (Netherlands)

    Dijk, C.; De Jong, P.J.


    It has been proposed that blushing-fearful individuals overestimate both the probability and the interpersonal costs of blushing. To study these judgmental biases, we presented a treatment-seeking sample of blushing-fearful individuals a series of vignettes describing social events and tested whethe

  1. Seeing ghosts: Negative body evaluation predicts overestimation of negative social feedback

    NARCIS (Netherlands)

    Alleva, J.M.; Lange, W.G.; Jansen, A.T.M.; Martijn, C.


    The current study investigated whether negative body evaluation predicts women's overestimation of negative social feedback related to their own body (i.e., covariation bias). Sixty-five female university students completed a computer task where photos of their own body, of a control woman's body, a

  2. Do currently recommended Bayley III cutoffs overestimate motor impairment in infants born <27 weeks gestation?


    Duncan, Andrea F; Bann, Carla; Boatman, Cathy; Hintz, Susan R.; Vaucher, Yvonne E.; Vohr, Betty R.; Yolton, Kimberly; Heyne, Roy J.; ,


    Objective To determine whether a Bayley-III Motor Composite score of 85 may overestimate moderate-severe motor impairment by analyzing Bayley-III motor components and developing cut-point scores for each. Study Design Retrospective study of 1183 children born

  3. Emotional time travel: Emotion regulation and the overestimation of future anger and sadness

    NARCIS (Netherlands)

    van Dijk, W.W.; van Dillen, L.F.; Seip, E.C.; Rotteveel, M.


    In the present study we examined the role of four specific forms of reappraisal in people's overestimation of their future experiences of anger and sadness. Results show that forecasters predicted to experience more intense anger and sadness following social exclusion than experiencers actually felt

  4. GOLD criteria overestimate airflow limitation in one-third of cases in the general Finnish population

    Directory of Open Access Journals (Sweden)

    Annette Kainu


    Full Text Available The Global Initiative for Chronic Obstructive Lung Disease (GOLD diagnostic criteria for chronic obstructive pulmonary disease (COPD use a fixed threshold of forced expiratory volume in 1 s (FEV1/forced vital capacity (FVC ratio (<0.70 in post-bronchodilation spirometry to indicate disease, which has been shown to underestimate and overestimate disease prevalence in younger and older adults, respectively, whilst criteria based on reference values have better accuracy. Differences in reference values have limited their use in international studies. However, the new Global Lung Function Initiative reference values (GLI2012 showed FEV1/FVC to be the least dependent on ethnicity. The aim of this study was to assess the prevalence of airflow limitation with GLI2012 and the degree of underdetection or overestimation related to the use of GOLD in the general population. A Finnish population sample of 1323 subjects (45% male with post-bronchodilation spirometry was studied. 80 subjects (6.0% and 55 subjects (4.2% were identified with airflow limitation with GOLD and GLI2012 criteria, respectively. The proportion of overestimation with GOLD increased with age from 25% of cases in 50-year-olds to 54% in 70-year-olds. Using z-score-based grading resulted in more dispersion in severity grading. In conclusion, the GOLD criteria cause a marked overestimation already from 50-year-olds and should be replaced with the GLI2012 criteria to improve diagnostic accuracy.

  5. The Validity of Conscientiousness Is Overestimated in the Prediction of Job Performance.

    Directory of Open Access Journals (Sweden)

    Sven Kepes

    Full Text Available Sensitivity analyses refer to investigations of the degree to which the results of a meta-analysis remain stable when conditions of the data or the analysis change. To the extent that results remain stable, one can refer to them as robust. Sensitivity analyses are rarely conducted in the organizational science literature. Despite conscientiousness being a valued predictor in employment selection, sensitivity analyses have not been conducted with respect to meta-analytic estimates of the correlation (i.e., validity between conscientiousness and job performance.To address this deficiency, we reanalyzed the largest collection of conscientiousness validity data in the personnel selection literature and conducted a variety of sensitivity analyses.Publication bias analyses demonstrated that the validity of conscientiousness is moderately overestimated (by around 30%; a correlation difference of about .06. The misestimation of the validity appears to be due primarily to suppression of small effects sizes in the journal literature. These inflated validity estimates result in an overestimate of the dollar utility of personnel selection by millions of dollars and should be of considerable concern for organizations.The fields of management and applied psychology seldom conduct sensitivity analyses. Through the use of sensitivity analyses, this paper documents that the existing literature overestimates the validity of conscientiousness in the prediction of job performance. Our data show that effect sizes from journal articles are largely responsible for this overestimation.

  6. Seeing ghosts: Negative body evaluation predicts overestimation of negative social feedback

    NARCIS (Netherlands)

    Alleva, J.M.; Lange, W.G.; Jansen, A.T.M.; Martijn, C.


    The current study investigated whether negative body evaluation predicts women's overestimation of negative social feedback related to their own body (i.e., covariation bias). Sixty-five female university students completed a computer task where photos of their own body, of a control woman's body, a

  7. Through rose-coloured glasses : An empirical test of narcissistic overestimation

    NARCIS (Netherlands)

    Lobbestael, Jill; de Bruin, Anique; Kok, Ellen; Voncken, Marisol


    BACKGROUND: Grandiosity is designated as a hallmark trait of narcissism. The current study tested whether narcissistic traits are related to overestimation of a range of agentic performances. METHOD: Eighty-five non-patients executed six objective tasks to assess their level of (emotional) intellige

  8. Emotional time travel: Emotion regulation and the overestimation of future anger and sadness

    NARCIS (Netherlands)

    van Dijk, W.W.; van Dillen, L.F.; Seip, E.C.; Rotteveel, M.


    In the present study we examined the role of four specific forms of reappraisal in people's overestimation of their future experiences of anger and sadness. Results show that forecasters predicted to experience more intense anger and sadness following social exclusion than experiencers actually

  9. Seeing ghosts: Negative body evaluation predicts overestimation of negative social feedback

    NARCIS (Netherlands)

    Alleva, J.M.; Lange, W.G.; Jansen, A.T.M.; Martijn, C.


    The current study investigated whether negative body evaluation predicts women's overestimation of negative social feedback related to their own body (i.e., covariation bias). Sixty-five female university students completed a computer task where photos of their own body, of a control woman's body,

  10. Significant uncertainty in global scale hydrological modeling from precipitation data errors

    NARCIS (Netherlands)

    Weiland, Frederiek C. Sperna; Vrugt, Jasper A.; van Beek, Rens (L. ) P. H.; Weerts, Albrecht H.; Bierkens, Marc F. P.


    In the past decades significant progress has been made in the fitting of hydrologic models to data. Most of this work has focused on simple, CPU-efficient, lumped hydrologic models using discharge, water table depth, soil moisture, or tracer data from relatively small river basins. In this paper, we

  11. Significant uncertainty in global scale hydrological modeling from precipitation data erros

    NARCIS (Netherlands)

    Sperna Weiland, F.; Vrugt, J.A.; Beek, van P.H.; Weerts, A.H.; Bierkens, M.F.P.


    In the past decades significant progress has been made in the fitting of hydrologic models to data. Most of this work has focused on simple, CPU-efficient, lumped hydrologic models using discharge, water table depth, soil moisture, or tracer data from relatively small river basins. In this paper, we

  12. The Significance of the Bystander Effect: Modeling, Experiments, and More Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, David J.


    Non-targeted (bystander) effects of ionizing radiation are caused by intercellular signaling; they include production of DNA damage and alterations in cell fate (i.e. apoptosis, differentiation, senescence or proliferation). Biophysical models capable of quantifying these effects may improve cancer risk estimation at radiation doses below the epidemiological detection threshold. Understanding the spatial patterns of bystander responses is important, because it provides estimates of how many bystander cells are affected per irradiated cell. In a first approach to modeling of bystander spatial effects in a three-dimensional artificial tissue, we assumed the following: (1) The bystander phenomenon results from signaling molecules (S) that rapidly propagate from irradiated cells and decrease in concentration (exponentially in the case of planar symmetry) as distance increases. (2) These signals can convert cells to a long-lived epigenetically activated state, e.g. a state of oxidative stress; cells in this state are more prone to DNA damage and behavior alterations than normal and therefore exhibit an increased response (R) for many end points (e.g. apoptosis, differentiation, micronucleation). These assumptions were implemented by a mathematical formalism and computational algorithms. The model adequately described data on bystander responses in the 3D system using a small number of adjustable parameters. Mathematical models of radiation carcinogenesis are important for understanding mechanisms and for interpreting or extrapolating risk. There are two classes of such models: (1) long-term formalisms that track pre-malignant cell numbers throughout an entire lifetime but treat initial radiation dose-response simplistically and (2) short-term formalisms that provide a detailed initial dose-response even for complicated radiation protocols, but address its modulation during the subsequent cancer latency period only indirectly. We argue that integrating short- and long

  13. Novel submicronized rebamipide liquid with moderate viscosity: significant effects on oral mucositis in animal models. (United States)

    Nakashima, Takako; Sako, Nobutomo; Matsuda, Takakuni; Uematsu, Naoya; Sakurai, Kazushi; Ishida, Tatsuhiro


    This study aimed at developing a novel rebamipide liquid for an effective treatment of oral mucositis. The healing effects of a variety of liquids comprising submicronized rebamipide crystals were investigated using a rat cauterization-induced oral ulcer model. Whereas 2% rebamipide liquid comprising micro-crystals did not exhibit significant curative effect, 2% rebamipide liquids comprising submicronized crystals with moderate viscosities exhibited healing effects following intra-oral administration. The 2% and 4% optimized rebamipide liquids showed significant healing effects in the rat oral ulcer model (prebamipide liquid significantly reduced the percent area of ulcerated injury (prebamipide liquid with moderate viscosity following intra-oral administration showed better both healing effect in the rat oral ulcer model and preventive effect in the rat irradiation-induced glossitis model.

  14. The quest for significance model of radicalization: implications for the management of terrorist detainees. (United States)

    Dugas, Michelle; Kruglanski, Arie W


    Radicalization and its culmination in terrorism represent a grave threat to the security and stability of the world. A related challenge is effective management of extremists who are detained in prison facilities. The major aim of this article is to review the significance quest model of radicalization and its implications for management of terrorist detainees. First, we review the significance quest model, which elaborates on the roles of motivation, ideology, and social processes in radicalization. Secondly, we explore the implications of the model in relation to the risks of prison radicalization. Finally, we analyze the model's implications for deradicalization strategies and review preliminary evidence for the effectiveness of a rehabilitation program targeting components of the significance quest. Based on this evidence, we argue that the psychology of radicalization provides compelling reason for the inclusion of deradicalization efforts as an essential component of the management of terrorist detainees. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Non-conventional modeling of extreme significant wave height through random sets

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi; LAM Jasmine Siu Lee


    The analysis and design of offshore structures necessitates the consideration of wave loads. Realistic model-ing of wave loads is particularly important to ensure reliable performance of these structures. Among the available methods for the modeling of the extreme significant wave height on a statistical basis, the peak over threshold method has attracted most attention. This method employs Poisson process to character-ize time-varying properties in the parameters of an extreme value distribution. In this paper, the peak over threshold method is reviewed and extended to account for subjectivity in the modeling. The freedom in selecting the threshold and the time span to separate extremes from the original time series data is incorpo-rated as imprecision in the model. This leads to an extension from random variables to random sets in the probabilistic model for the extreme significant wave height. The extended model is also applied to different periods of the sampled data to evaluate the significance of the climatic conditions on the uncertainties of the parameters.

  16. Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter (United States)

    Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen


    Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial “DOK.” We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0–0.25, 0.25–0.5, 0.5–0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and

  17. Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter. (United States)

    Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen


    Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial "DOK." We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0-0.25, 0.25-0.5, 0.5-0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and estimations

  18. Teaching physical activities to students with significant disabilities using video modeling. (United States)

    Cannella-Malone, Helen I; Mizrachi, Sharona V; Sabielny, Linsey M; Jimenez, Eliseo D


    The objective of this study was to examine the effectiveness of video modeling on teaching physical activities to three adolescents with significant disabilities. The study implemented a multiple baseline across six physical activities (three per student): jumping rope, scooter board with cones, ladder drill (i.e., feet going in and out), ladder design (i.e., multiple steps), shuttle run, and disc ride. Additional prompt procedures (i.e., verbal, gestural, visual cues, and modeling) were implemented within the study. After the students mastered the physical activities, we tested to see if they would link the skills together (i.e., complete an obstacle course). All three students made progress learning the physical activities, but only one learned them with video modeling alone (i.e., without error correction). Video modeling can be an effective tool for teaching students with significant disabilities various physical activities, though additional prompting procedures may be needed.

  19. Latent and sensible heat fluxes overestimated and net heat flux underestimated in Lake Victoria

    CERN Document Server

    Verburg, Piet


    Cozar et al. (2012) used remotely-sensed data to link phytoplankton growth to the net heat flux in both the northern and southern parts of Lake Victoria. However, the latent and sensible heat fluxes were overestimated by ~26% by assuming a constant air density of 1.3 kg m-3. As a result, the net heat flux was underestimated, bringing into question conclusions regarding the convective circulation.

  20. Impact of urban expansion on meteorological observation data and overestimation to regional air temperature in China

    Institute of Scientific and Technical Information of China (English)

    SHAO Quanqin; SUN Chaoyang; LIU Jiyuan; HE Jianfeng; KUANG Wenhui; TAO Fulu


    Since the implementation of the reform and opening up policy in China in the late 1970s,some meteorological stations 'entered' cities passively due to urban expansion.Changes in the surface and built environment around the stations have influenced observations of air temperature.When the observational data from urban stations are applied in the interpolation of national or regional scale air temperature dataset,they could lead to overestimation of regional air temperature and inaccurate assessment of warming.In this study,the underlying surface surrounding 756 meteorological stations across China was identified based on remote sensing images over a number of time intervals to distinguish the rural stations that 'entered' into cities.Then,after removing the observational data from these stations which have been influenced by urban expansion,a dataset of background air temperatures was generated by interpolating the observational data from the remaining rural stations.The mean urban heat island effect intensity since 1970 was estimated by comparing the original observational records from urban stations with the background air temperature interpolated.The result shows that urban heat island effect does occur due to urban expansion,with a higher intensity in winter than in other seasons.Then the overestimation of regional air temperature is evaluated by comparing the two kinds of grid datasets of air temperature which are respectively interpolated by all stations' and rural stations' observational data.Spatially,the overestimation is relatively higher in eastern China than in the central part of China; however,both areas exhibit a much higher effect than is observed in western China.We concluded that in the last 40 years the mean temperature in China increased by about 1.58℃,of which about 0.01℃ was attributed to urban expansion,with a contribution of up to 0.09℃ in the core areas from the overestimation of air temperature.

  1. A new model to estimate significant wave heights with ERS-1/2 scatterometer data

    Institute of Scientific and Technical Information of China (English)

    GUO Jie; HE Yijun; William Perrie; SHEN Hui; CHU Xiaoqing


    A new model is proposed to estimate the significant wave heights with ERS-1/2 scatterometer data. The results show that the relationship between wave parameters and radar backscattering cross section is similar to that between wind and the radar backscattering cross section. Therefore, the relationship between significant wave height and the radar backscattering cross section is established with a neural network algorithm, which is, if the average wave period is ≤7s, the root mean square of significant wave height retrieved from ERS-1/2 data is 0.51 m, or 0.72 m if it is >7s otherwise.

  2. Significance of exchanging SSURGO and STATSGO data when modeling hydrology in diverse physiographic terranes (United States)

    Williamson, Tanja N.; Taylor, Charles J.; Newson, Jeremy K.


    The Water Availability Tool for Environmental Resources (WATER) is a TOPMODEL-based hydrologic model that depends on spatially accurate soils data to function in diverse terranes. In Kentucky, this includes mountainous regions, karstic plateau, and alluvial plains. Soils data are critical because they quantify the space to store water, as well as how water moves through the soil to the stream during storm events. We compared how the model performs using two different sources of soils data--Soil Survey Geographic Database (SSURGO) and State Soil Geographic Database laboratory data (STATSGO)--for 21 basins ranging in size from 17 to 1564 km2. Model results were consistently better when SSURGO data were used, likely due to the higher field capacity, porosity, and available-water holding capacity, which cause the model to store more soil-water in the landscape and improve streamflow estimates for both low- and high-flow conditions. In addition, there were significant differences in the conductivity multiplier and scaling parameter values that describe how water moves vertically and laterally, respectively, as quantified by TOPMODEL. We also evaluated whether partitioning areas that drain to streams via sinkholes in karstic basins as separate hydrologic modeling units (HMUs) improved model performance. There were significant differences between HMUs in properties that control soil-water storage in the model, although the effect of partitioning these HMUs on streamflow simulation was inconclusive.

  3. Is the prevalence of overactive bladder overestimated? A population-based study in Finland.

    Directory of Open Access Journals (Sweden)

    Kari A O Tikkinen

    Full Text Available BACKGROUND: In earlier studies, one in six adults had overactive bladder which may impair quality of life. However, earlier studies have either not been population-based or have suffered from methodological limitations. Our aim was to assess the prevalence of overactive bladder symptoms, based on a representative study population and using consistent definitions and exclusions. METHODOLOGY/PRINCIPAL FINDINGS: The aim of the study was to assess the age-standardized prevalence of overactive bladder defined as urinary urgency, with or without urgency incontinence, usually with urinary frequency and nocturia in the absence of urinary tract infection or other obvious pathology. In 2003-2004, a questionnaire was mailed to 6,000 randomly selected Finns aged 18-79 years who were identified from the Finnish Population Register Centre. Information on voiding symptoms was collected using the validated Danish Prostatic Symptom Score, with additional frequency and nocturia questions. Corrected prevalence was calculated with adjustment for selection bias due to non-response. The questionnaire also elicited co-morbidity and socio-demographic information. Of the 6,000 subjects, 62.4% participated. The prevalence of overactive bladder was 6.5% (95% CI, 5.5% to 7.6% for men and 9.3% (CI, 7.9% to 10.6% for women. Exclusion of men with benign prostatic hyperplasia reduced prevalence among men by approximately one percentage point (to 5.6% [CI, 4.5% to 6.6%]. Among subjects with overactive bladder, urgency incontinence, frequency, and nocturia were reported by 11%, 23%, and 56% of men and 27%, 38%, and 40% of women, respectively. However, only 31% of men and 35% of women with frequency, and 31% of subjects of both sexes with nocturia reported overactive bladder. CONCLUSIONS/SIGNIFICANCE: Our results indicate a prevalence of overactive bladder as low as 8% suggesting that, in previous studies, occurrence has been overestimated due to vague criteria and selected study

  4. Strategies for Testing Statistical and Practical Significance in Detecting DIF with Logistic Regression Models (United States)

    Fidalgo, Angel M.; Alavi, Seyed Mohammad; Amirian, Seyed Mohammad Reza


    This study examines three controversial aspects in differential item functioning (DIF) detection by logistic regression (LR) models: first, the relative effectiveness of different analytical strategies for detecting DIF; second, the suitability of the Wald statistic for determining the statistical significance of the parameters of interest; and…

  5. On the significance of the Nash-Sutcliffe efficiency measure for event-based flood models (United States)

    Moussa, Roger


    When modelling flood events, the important challenge that awaits the modeller is first to choose a rainfall-runoff model, then to calibrate a set of parameters that can accurately simulate a number of flood events and related hydrograph shapes, and finally to evaluate the model performance separately on each event using multi-criteria functions. This study analyses the significance of the Nash-Sutcliffe efficiency (NSE) and proposes a new method to assess the performance of flood event models (see Moussa, 2010, "When monstrosity can be beautiful while normality can be ugly : assessing the performance of event-based-flood-models", Hydrological Science Journal, in press). We focus on the specific cases of events difficult to model and characterized by low NSE values, which we call "monsters". The properties of the NSE were analysed as a function of the calculated hydrograph shape and of the benchmark reference model. As application case, a multi-criteria analysis method to assess the model performance on each event is proposed and applied on the Gardon d'Anduze catchment. This paper discusses first the significance of the well-known Nash-Sutcliffe efficiency (NSE) criteria function when calculated separately on flood events. The NSE is a convenient and normalized measure of model performance, but does not provide a reliable basis for comparing the results of different case studies. We show that simulated hydrographs with low or negative values of NSE, called "monsters", can be due solely to a simple lag translation or a homothetic ratio of the observed hydrograph which reproduces the dynamic of the hydrograph, with acceptable errors on other criteria. In the opposite, results show that simulations with a NSE close to 1 can become "monsters" and give very low values (even negative) of the criteria function G, if the average observed discharged used as a benchmark reference model in the NSE is modified. This paper argues that the definition of an appropriate benchmark

  6. Using animal models to determine the significance of complement activation in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Loeffler David A


    Full Text Available Abstract Complement inflammation is a major inflammatory mechanism whose function is to promote the removal of microorganisms and the processing of immune complexes. Numerous studies have provided evidence for an increase in this process in areas of pathology in the Alzheimer's disease (AD brain. Because complement activation proteins have been demonstrated in vitro to exert both neuroprotective and neurotoxic effects, the significance of this process in the development and progression of AD is unclear. Studies in animal models of AD, in which brain complement activation can be experimentally altered, should be of value for clarifying this issue. However, surprisingly little is known about complement activation in the transgenic animal models that are popular for studying this disorder. An optimal animal model for studying the significance of complement activation on Alzheimer's – related neuropathology should have complete complement activation associated with senile plaques, neurofibrillary tangles (if present, and dystrophic neurites. Other desirable features include both classical and alternative pathway activation, increased neuronal synthesis of native complement proteins, and evidence for an increase in complement activation prior to the development of extensive pathology. In order to determine the suitability of different animal models for studying the role of complement activation in AD, the extent of complement activation and its association with neuropathology in these models must be understood.

  7. Field significance of performance measures in the context of regional climate model evaluation. Part 2: precipitation (United States)

    Ivanov, Martin; Warrach-Sagi, Kirsten; Wulfmeyer, Volker


    A new approach for rigorous spatial analysis of the downscaling performance of regional climate model (RCM) simulations is introduced. It is based on a multiple comparison of the local tests at the grid cells and is also known as `field' or `global' significance. The block length for the local resampling tests is precisely determined to adequately account for the time series structure. New performance measures for estimating the added value of downscaled data relative to the large-scale forcing fields are developed. The methodology is exemplarily applied to a standard EURO-CORDEX hindcast simulation with the Weather Research and Forecasting (WRF) model coupled with the land surface model NOAH at 0.11 ∘ grid resolution. Daily precipitation climatology for the 1990-2009 period is analysed for Germany for winter and summer in comparison with high-resolution gridded observations from the German Weather Service. The field significance test controls the proportion of falsely rejected local tests in a meaningful way and is robust to spatial dependence. Hence, the spatial patterns of the statistically significant local tests are also meaningful. We interpret them from a process-oriented perspective. While the downscaled precipitation distributions are statistically indistinguishable from the observed ones in most regions in summer, the biases of some distribution characteristics are significant over large areas in winter. WRF-NOAH generates appropriate stationary fine-scale climate features in the daily precipitation field over regions of complex topography in both seasons and appropriate transient fine-scale features almost everywhere in summer. As the added value of global climate model (GCM)-driven simulations cannot be smaller than this perfect-boundary estimate, this work demonstrates in a rigorous manner the clear additional value of dynamical downscaling over global climate simulations. The evaluation methodology has a broad spectrum of applicability as it is

  8. Does Statistical Significance Help to Evaluate Predictive Performance of Competing Models?

    Directory of Open Access Journals (Sweden)

    Levent Bulut


    Full Text Available In Monte Carlo experiment with simulated data, we show that as a point forecast criterion, the Clark and West's (2006 unconditional test of mean squared prediction errors does not reflect the relative performance of a superior model over a relatively weaker one. The simulation results show that even though the mean squared prediction errors of a constructed superior model is far below a weaker alternative, the Clark- West test does not reflect this in their test statistics. Therefore, studies that use this statistic in testing the predictive accuracy of alternative exchange rate models, stock return predictability, inflation forecasting, and unemployment forecasting should not weight too much on the magnitude of the statistically significant Clark-West tests statistics.

  9. A background error covariance model of significant wave height employing Monte Carlo simulation

    Institute of Scientific and Technical Information of China (English)

    GUO Yanyou; HOU Yijun; ZHANG Chunmei; YANG Jie


    The quality of background error statistics is one of the key components for successful assimilation of observations in a numerical model.The background error covariance(BEC)of ocean waves is generally estimated under an assumption that it is stationary over a period of time and uniform over a domain.However,error statistics are in fact functions of the physical processes governing the meteorological situation and vary with the wave condition.In this paper,we simulated the BEC of the significant wave height(SWH)employing Monte Carlo methods.An interesting result is that the BEC varies consistently with the mean wave direction(MWD).In the model domain,the BEC of the SWH decreases significantly when the MWD changes abruptly.A new BEC model of the SWH based on the correlation between the BEC and MWD was then developed.A case study of regional data assimilation was performed,where the SWH observations of buoy 22001 were used to assess the SWH hindcast.The results show that the new BEC model benefits wave prediction and allows reasonable approximations of anisotropy and inhomogeneous errors.

  10. Significance of settling model structures and parameter subsets in modelling WWTPs under wet-weather flow and filamentous bulking conditions. (United States)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen; Plósz, Benedek Gy


    Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of ideal and non-ideal flow (dry and wet weather) and settling (good settling and bulking) boundary conditions on the sensitivity of WWTP model outputs to uncertainties intrinsic to the one-dimensional (1-D) SST model structures and parameters. We identify the critical sources of uncertainty in WWTP models through global sensitivity analysis (GSA) using the Benchmark simulation model No. 1 in combination with first- and second-order 1-D SST models. The results obtained illustrate that the contribution of settling parameters to the total variance of the key WWTP process outputs significantly depends on the influent flow and settling conditions. The magnitude of the impact is found to vary, depending on which type of 1-D SST model is used. Therefore, we identify and recommend potential parameter subsets for WWTP model calibration, and propose optimal choice of 1-D SST models under different flow and settling boundary conditions. Additionally, the hydraulic parameters in the second-order SST model are found significant under dynamic wet-weather flow conditions. These results highlight the importance of developing a more mechanistic based flow-dependent hydraulic sub-model in second-order 1-D SST models in the future.

  11. The constant work rate critical power protocol overestimates ramp incremental exercise performance. (United States)

    Black, Matthew I; Jones, Andrew M; Kelly, James A; Bailey, Stephen J; Vanhatalo, Anni


    The parameters of the power-duration relationship (i.e., the critical power, CP, and the curvature constant, W') may theoretically predict maximal performance capability for exercise above the CP. The CP and W' are associated with the parameters of oxygen uptake ([Formula: see text]O2) kinetics, which can be altered by manipulation of the work-rate forcing function. We tested the hypothesis that the CP and W' derived from constant work-rate (CWR) prediction trials would overestimate ramp incremental exercise performance. Thirty subjects (males, n = 28; females, n = 2) performed a ramp incremental test, and 3-5 CWR prediction trials for the determination of the CP and W'. Multiple ramp incremental tests and corresponding CP and W' estimates were available for some subjects such that in total 51 ramp test performances were predicted. The ramp incremental test performance (729 ± 113 s) was overestimated by the CP and W' estimates derived from the best (751 ± 114 s, P incremental performance suggests that the CP and W' derived from different work-rate forcing functions, thus resulting in different [Formula: see text]O2 kinetics, cannot be used interchangeably. The present findings highlight a potential source of error in performance prediction that is of importance to both researchers and applied practitioners.

  12. A single 24 h recall overestimates exclusive breastfeeding practices among infants aged less than six months in rural Ethiopia. (United States)

    Fenta, Esete Habtemariam; Yirgu, Robel; Shikur, Bilal; Gebreyesus, Seifu Hagos


    Exclusive breastfeeding (EBF) to six months is one of the World Health Organization's (WHOs) infant and young child feeding (IYCF) core indicators. Single 24 h recall method is currently in use to measure exclusive breastfeeding practice among children of age less than six months. This approach overestimates the prevalence of EBF, especially among small population groups. This justifies the need to look for alternative measurement techniques to have a valid estimate regardless of population characteristics. The study involved 422 infants of age less than six months, living in Gurage zone, Southern Ethiopia. The study was conducted from January to February 2016. Child feeding practices were measured for seven consecutive days using 24 h recall method. Recall since birth, was used to measure breastfeeding practices from birth to the day of data collection. Data on EBF obtained by using single 24 h recall were compared with seven days repeated 24 h recall method. McNemar's test was done to assess if a significant difference existed in rates of EBF between measurement methods. The mean age of infants in months was 3 (SD -1.43). Exclusive breastfeeding prevalence was highest (76.7%; 95% CI 72.6, 80.8) when EBF was estimated using single 24 h recall. The prevalence of EBF based on seven repeated 24 h recall was 53.2% (95% CI: 48.3, 58.0). The estimated prevalence of EBF since birth based on retrospective data (recall since birth) was 50.2% (95% CI 45.4, 55.1). Compared to the EBF estimates obtained from seven repeated 24 h recall, single 24 h recall overestimated EBF magnitude by 23 percentage points (95% CI 19.2, 27.8). As the number of days of 24 h recall increased, a significant decrease in overestimation of EBF was observed. A significant overestimation was observed when single 24 h recall was used to estimate prevalence of EBF compared to seven days of 24 h recall. By increasing the observation days we can significantly decrease the degree of

  13. Significant glial alterations in response to iron loading in a novel organotypic hippocampal slice culture model (United States)

    Healy, Sinead; McMahon, Jill; Owens, Peter; FitzGerald, Una


    Aberrant iron deposition in the brain is associated with neurodegenerative disorders including Multiple Sclerosis, Alzheimer’s disease and Parkinson’s disease. To study the collective response to iron loading, we have used hippocampal organotypic slices as a platform to develop a novel ex vivo model of iron accumulation. We demonstrated differential uptake and toxicity of iron after 12 h exposure to 10 μM ferrous ammonium sulphate, ferric citrate or ferrocene. Having established the supremacy of ferrocene in this model, the cultures were then loaded with 0.1–100 μM ferrocene for 12 h. One μM ferrocene exposure produced the maximal 1.6-fold increase in iron compared with vehicle. This was accompanied by a 1.4-fold increase in ferritin transcripts and mild toxicity. Using dual-immunohistochemistry, we detected ferritin in oligodendrocytes, microglia, but rarely in astrocytes and never in neurons in iron-loaded slice cultures. Moreover, iron loading led to a 15% loss of olig2-positive cells and a 16% increase in number and greater activation of microglia compared with vehicle. However, there was no appreciable effect of iron loading on astrocytes. In what we believe is a significant advance on traditional mono- or dual-cultures, our novel ex vivo slice-culture model allows characterization of the collective response of brain cells to iron-loading. PMID:27808258

  14. A Parallelized Pumpless Artificial Placenta System Significantly Prolonged Survival Time in a Preterm Lamb Model. (United States)

    Miura, Yuichiro; Matsuda, Tadashi; Usuda, Haruo; Watanabe, Shimpei; Kitanishi, Ryuta; Saito, Masatoshi; Hanita, Takushi; Kobayashi, Yoshiyasu


    An artificial placenta (AP) is an arterio-venous extracorporeal life support system that is connected to the fetal circulation via the umbilical vasculature. Previously, we published an article describing a pumpless AP system with a small priming volume. We subsequently developed a parallelized system, hypothesizing that the reduced circuit resistance conveyed by this modification would enable healthy fetal survival time to be prolonged. We conducted experiments using a premature lamb model to test this hypothesis. As a result, the fetal survival period was significantly prolonged (60.4 ± 3.8 vs. 18.2 ± 3.2 h, P < 0.01), and circuit resistance and minimal blood lactate levels were significantly lower in the parallel circuit group, compared with our previous single circuit group. Fetal physiological parameters remained stable until the conclusion of the experiments. In summary, parallelization of the AP system was associated with reduced circuit resistance and lactate levels and allowed preterm lamb fetuses to survive for a significantly longer period when compared with previous studies.

  15. Phasic firing in vasopressin cells: understanding its functional significance through computational models.

    Directory of Open Access Journals (Sweden)

    Duncan J MacGregor

    Full Text Available Vasopressin neurons, responding to input generated by osmotic pressure, use an intrinsic mechanism to shift from slow irregular firing to a distinct phasic pattern, consisting of long bursts and silences lasting tens of seconds. With increased input, bursts lengthen, eventually shifting to continuous firing. The phasic activity remains asynchronous across the cells and is not reflected in the population output signal. Here we have used a computational vasopressin neuron model to investigate the functional significance of the phasic firing pattern. We generated a concise model of the synaptic input driven spike firing mechanism that gives a close quantitative match to vasopressin neuron spike activity recorded in vivo, tested against endogenous activity and experimental interventions. The integrate-and-fire based model provides a simple physiological explanation of the phasic firing mechanism involving an activity-dependent slow depolarising afterpotential (DAP generated by a calcium-inactivated potassium leak current. This is modulated by the slower, opposing, action of activity-dependent dendritic dynorphin release, which inactivates the DAP, the opposing effects generating successive periods of bursting and silence. Model cells are not spontaneously active, but fire when perturbed by random perturbations mimicking synaptic input. We constructed one population of such phasic neurons, and another population of similar cells but which lacked the ability to fire phasically. We then studied how these two populations differed in the way that they encoded changes in afferent inputs. By comparison with the non-phasic population, the phasic population responds linearly to increases in tonic synaptic input. Non-phasic cells respond to transient elevations in synaptic input in a way that strongly depends on background activity levels, phasic cells in a way that is independent of background levels, and show a similar strong linearization of the response

  16. A systematic experimental investigation of significant parameters affecting model tire hydroplaning (United States)

    Wray, G. A.; Ehrlich, I. R.


    The results of a comprehensive parametric study of model and small pneumatic tires operating on a wet surface are presented. Hydroplaning inception (spin down) and rolling restoration (spin up) are discussed. Conclusions indicate that hydroplaning inception occurs at a speed significantly higher than the rolling restoration speed. Hydroplaning speed increases considerably with tread depth, surface roughness and tire inflation pressure of footprint pressure, and only moderately with increased load. Water film thickness affects spin down speed only slightly. Spin down speed varies inversely as approximately the one-sixth power of film thickness. Empirical equations relating tire inflation pressure, normal load, tire diameter and water film thickness have been generated for various tire tread and surface configurations.

  17. Computer modeling of gastric parietal cell: significance of canalicular space, gland lumen, and variable canalicular [K+]. (United States)

    Crothers, James M; Forte, John G; Machen, Terry E


    A computer model, constructed for evaluation of integrated functioning of cellular components involved in acid secretion by the gastric parietal cell, has provided new interpretations of older experimental evidence, showing the functional significance of a canalicular space separated from a mucosal bath by a gland lumen and also shedding light on basolateral Cl(-) transport. The model shows 1) changes in levels of parietal cell secretion (with stimulation or H-K-ATPase inhibitors) result mainly from changes in electrochemical driving forces for apical K(+) and Cl(-) efflux, as canalicular [K(+)] ([K(+)]can) increases or decreases with changes in apical H(+)/K(+) exchange rate; 2) H-K-ATPase inhibition in frog gastric mucosa would increase [K(+)]can similarly with low or high mucosal [K(+)], depolarizing apical membrane voltage similarly, so electrogenic H(+) pumping is not indicated by inhibition causing similar increase in transepithelial potential difference (Vt) with 4 and 80 mM mucosal K(+); 3) decreased H(+) secretion during strongly mucosal-positive voltage clamping is consistent with an electroneutral H-K-ATPase being inhibited by greatly decreased [K(+)]can (Michaelis-Menten mechanism); 4) slow initial change ("long time-constant transient") in current or Vt with clamping of Vt or current involves slow change in [K(+)]can; 5) the Na(+)-K(+)-2Cl(-) symporter (NKCC) is likely to have a significant role in Cl(-) influx, despite evidence that it is not necessary for acid secretion; and 6) relative contributions of Cl(-)/HCO3 (-) exchanger (AE2) and NKCC to Cl(-) influx would differ greatly between resting and stimulated states, possibly explaining reported differences in physiological characteristics of stimulated open-circuit Cl(-) secretion (≈H(+)) and resting short-circuit Cl(-) secretion (>H(+)).

  18. Extrinsic value orientation and affective forecasting: overestimating the rewards, underestimating the costs. (United States)

    Sheldon, Kennon M; Gunz, Alexander; Nichols, Charles P; Ferguson, Yuna


    We examined affective forecasting errors as a possible explanation of the perennial appeal of extrinsic values and goals. Study 1 found that although people relatively higher in extrinsic (money, fame, image) compared to intrinsic (growth, intimacy, community) value orientation (REVO) are less happy, they nevertheless believe that attaining extrinsic goals offers a strong potential route to happiness. Study 2's longitudinal experimental design randomly assigned participants to pursue either 3 extrinsic or 3 intrinsic goals over 4 weeks, and REVO again predicted stronger forecasts regarding extrinsic goals. However, not even extrinsically oriented participants gained well-being benefits from attaining extrinsic goals, whereas all participants tended to gain in happiness from attaining intrinsic goals. Study 3 showed that the effect of REVO on forecasts is mediated by extrinsic individuals' belief that extrinsic goals will satisfy autonomy and competence needs. It appears that some people overestimate the emotional benefits of achieving extrinsic goals, to their potential detriment.

  19. Effect of Speed Overestimation on Flash-Lag Effect at Low Luminance

    Directory of Open Access Journals (Sweden)

    Maryam Vaziri-Pashkam


    Full Text Available When a brief flash is presented at the same location as a moving object, the flash is perceived to lag behind the moving object to an extent that increases with the speed of the object. Previous studies showed that moving objects appear faster at low luminance as a result of their longer motion trace. Here we examine whether this faster perceived motion also affects the amount of the flash lag at low luminance. We first verified that speed was overestimated at low luminance with our stimulus. We then asked subjects to align a briefly flashed dot with the moving target. Results showed that the flash-lag effect increased with physical speed at both high and low luminance, but there was no additional increase due to the perceived increase of speed at low luminance. We suggest that although motion blur contributes to perceived speed, it does not contribute to the speed information that influences its perceived position.

  20. Seeing ghosts: negative body evaluation predicts overestimation of negative social feedback. (United States)

    Alleva, Jessica M; Lange, Wolf-Gero; Jansen, Anita; Martijn, Carolien


    The current study investigated whether negative body evaluation predicts women's overestimation of negative social feedback related to their own body (i.e., covariation bias). Sixty-five female university students completed a computer task where photos of their own body, of a control woman's body, and of a neutral object, were followed by nonverbal social feedback (i.e., facial crowds with equal numbers of negative, positive, and neutral faces). Afterward, women estimated the percentage of negative, positive, and neutral social feedback that followed their own body, the control woman's body, and the neutral object. The findings provided evidence for a covariation bias: negative body evaluation predicted higher estimates of negative social feedback for women's own body, but not for the other stimuli. Additionally, the covariation bias was not explained by differences in how women interpreted the social feedback (the facial stimuli). Clinical implications of the covariation bias to body image are discussed.

  1. Overestimation of organic phosphorus in wetland soils by alkaline extraction and molybdate colorimetry. (United States)

    Turner, Benjamin L; Newman, Susan; Reddy, K Ramesh


    Accurate information on the chemical nature of soil phosphorus is essential for understanding its bioavailability and fate in wetland ecosystems. Solution phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy was used to assess the conventional colorimetric procedure for phosphorus speciation in alkaline extracts of organic soils from the Florida Everglades. Molybdate colorimetry markedly overestimated organic phosphorus by between 30 and 54% compared to NMR spectroscopy. This was due in large part to the association of inorganic phosphate with organic matter, although the error was exacerbated in some samples by the presence of pyrophosphate, an inorganic polyphosphate that is not detected by colorimetry. The results have important implications for our understanding of phosphorus biogeochemistry in wetlands and suggest that alkaline extraction and solution 31p NMR spectroscopy is the only accurate method for quantifying organic phosphorus in wetland soils.

  2. Significant Features Found in Simulated Tropical Climates Using a Cloud Resolving Model (United States)

    Shie, C.-L.; Tao, W.-K.; Simpson, J.; Sui, C.-H.


    Cloud resolving model (CRM) has widely been used in recent years for simulations involving studies of radiative-convective systems and their role in determining the tropical regional climate. The growing popularity of CRMs usage can be credited for their inclusion of crucial and realistic features such like explicit cloud-scale dynamics, sophisticated microphysical processes, and explicit radiative-convective interaction. For example, by using a two-dimensional cloud model with radiative-convective interaction process, found a QBO-like (quasibiennial oscillation) oscillation of mean zonal wind that affected the convective system. Accordingly, the model-generated rain band corresponding to convective activity propagated in the direction of the low-level zonal mean winds; however, the precipitation became "localized" (limited within a small portion of the domain) as zonal mean winds were removed. Two other CRM simulations by S94 and Grabowski et al. (1996, hereafter G96), respectively that produced distinctive quasi-equilibrium ("climate") states on both tropical water and energy, i.e., a cold/dry state in S94 and a warm/wet state in G96, have later been investigated by T99. They found that the pattern of the imposed large-scale horizontal wind and the magnitude of the imposed surface fluxes were the two crucial mechanisms in determining the tropical climate states. The warm/wet climate was found associated with prescribed strong surface winds, or with maintained strong vertical wind shears that well-organized convective systems prevailed. On the other hand, the cold/dry climate was produced due to imposed weak surface winds and weak wind shears throughout a vertically mixing process by convection. In this study, considered as a sequel of T99, the model simulations to be presented are generally similar to those of T99 (where a detailed model setup can be found), except for a more detailed discussion along with few more simulated experiments. There are twelve major

  3. Significance tests to determine the direction of effects in linear regression models. (United States)

    Wiedermann, Wolfgang; Hagmann, Michael; von Eye, Alexander


    Previous studies have discussed asymmetric interpretations of the Pearson correlation coefficient and have shown that higher moments can be used to decide on the direction of dependence in the bivariate linear regression setting. The current study extends this approach by illustrating that the third moment of regression residuals may also be used to derive conclusions concerning the direction of effects. Assuming non-normally distributed variables, it is shown that the distribution of residuals of the correctly specified regression model (e.g., Y is regressed on X) is more symmetric than the distribution of residuals of the competing model (i.e., X is regressed on Y). Based on this result, 4 one-sample tests are discussed which can be used to decide which variable is more likely to be the response and which one is more likely to be the explanatory variable. A fifth significance test is proposed based on the differences of skewness estimates, which leads to a more direct test of a hypothesis that is compatible with direction of dependence. A Monte Carlo simulation study was performed to examine the behaviour of the procedures under various degrees of associations, sample sizes, and distributional properties of the underlying population. An empirical example is given which illustrates the application of the tests in practice.

  4. Pharmacological kynurenine 3-monooxygenase enzyme inhibition significantly reduces neuropathic pain in a rat model. (United States)

    Rojewska, Ewelina; Piotrowska, Anna; Makuch, Wioletta; Przewlocka, Barbara; Mika, Joanna


    Recent studies have highlighted the involvement of the kynurenine pathway in the pathology of neurodegenerative diseases, but the role of this system in neuropathic pain requires further extensive research. Therefore, the aim of our study was to examine the role of kynurenine 3-monooxygenase (Kmo), an enzyme that is important in this pathway, in a rat model of neuropathy after chronic constriction injury (CCI) to the sciatic nerve. For the first time, we demonstrated that the injury-induced increase in the Kmo mRNA levels in the spinal cord and the dorsal root ganglia (DRG) was reduced by chronic administration of the microglial inhibitor minocycline and that this effect paralleled a decrease in the intensity of neuropathy. Further, minocycline administration alleviated the lipopolysaccharide (LPS)-induced upregulation of Kmo mRNA expression in microglial cell cultures. Moreover, we demonstrated that not only indirect inhibition of Kmo using minocycline but also direct inhibition using Kmo inhibitors (Ro61-6048 and JM6) decreased neuropathic pain intensity on the third and the seventh days after CCI. Chronic Ro61-6048 administration diminished the protein levels of IBA-1, IL-6, IL-1beta and NOS2 in the spinal cord and/or the DRG. Both Kmo inhibitors potentiated the analgesic properties of morphine. In summary, our data suggest that in neuropathic pain model, inhibiting Kmo function significantly reduces pain symptoms and enhances the effectiveness of morphine. The results of our studies show that the kynurenine pathway is an important mediator of neuropathic pain pathology and indicate that Kmo represents a novel pharmacological target for the treatment of neuropathy.

  5. Cyclosporin A significantly improves preeclampsia signs and suppresses inflammation in a rat model. (United States)

    Hu, Bihui; Yang, Jinying; Huang, Qian; Bao, Junjie; Brennecke, Shaun Patrick; Liu, Huishu


    Preeclampsia is associated with an increased inflammatory response. Immune suppression might be an effective treatment. The aim of this study was to examine whether Cyclosporin A (CsA), an immunosuppressant, improves clinical characteristics of preeclampsia and suppresses inflammation in a lipopolysaccharide (LPS) induced preeclampsia rat model. Pregnant rats were randomly divided into 4 groups: group 1 (PE) rats each received LPS via tail vein on gestational day (GD) 14; group 2 (PE+CsA5) rats were pretreated with LPS (1.0 μg/kg) on GD 14 and were then treated with CsA (5mg/kg, ip) on GDs 16, 17 and 18; group 3 (PE+CsA10) rats were pretreated with LPS (1.0 μg/kg) on GD 14 and were then treated with CsA (10mg/kg, ip) on GDs 16, 17 and 18; group 4 (pregnant control, PC) rats were treated with the vehicle (saline) used for groups 1, 2 and 3. Systolic blood pressure, urinary albumin, biometric parameters and the levels of serum cytokines were measured on day 20. CsA treatment significantly reduced LPS-induced systolic blood pressure and the mean 24-h urinary albumin excretion. Pro-inflammatory cytokines IL-6, IL-17, IFN-γ and TNF-α were increased in the LPS treatment group but were reduced in (LPS+CsA) group (PCyclosporine A improved preeclampsia signs and attenuated inflammatory responses in the LPS induced preeclampsia rat model which suggests that immunosuppressant might be an alternative management option for preeclampsia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Prostate cancer risk and DNA damage: translational significance of selenium supplementation in a canine model. (United States)

    Waters, David J; Shen, Shuren; Glickman, Lawrence T; Cooley, Dawn M; Bostwick, David G; Qian, Junqi; Combs, Gerald F; Morris, J Steven


    Daily supplementation with the essential trace mineral selenium significantly reduced prostate cancer risk in men in the Nutritional Prevention of Cancer Trial. However, the optimal intake of selenium for prostate cancer prevention is unknown. We hypothesized that selenium significantly regulates the extent of genotoxic damage within the aging prostate and that the relationship between dietary selenium intake and DNA damage is non-linear, i.e. more selenium is not necessarily better. To test this hypothesis, we conducted a randomized feeding trial in which 49 elderly beagle dogs (physiologically equivalent to 62-69-year-old men) received nutritionally adequate or supranutritional levels of selenium for 7 months, in order to mimic the range of dietary selenium intake of men in the United States. Our results demonstrate an intriguing U-shaped dose-response relationship between selenium status (toenail selenium concentration) and the extent of DNA damage (alkaline Comet assay) within the prostate. Further, we demonstrate that the concentration of selenium that minimizes DNA damage in the aging dog prostate remarkably parallels the selenium concentration in men that minimizes prostate cancer risk. By studying elderly dogs, the only non-human animal model of spontaneous prostate cancer, we have established a new approach to bridge the gap between laboratory and human studies that can be used to select the appropriate dose of anticancer agents for large-scale human cancer prevention trials. From the U-shaped dose-response, it follows that not all men will necessarily benefit from increasing their selenium intake and that measurement of baseline nutrient status should be required for all individuals in prevention trials to avoid oversupplementation.

  7. Kernel density surface modelling as a means to identify significant concentrations of vulnerable marine ecosystem indicators.

    Directory of Open Access Journals (Sweden)

    Ellen Kenchington

    Full Text Available The United Nations General Assembly Resolution 61/105, concerning sustainable fisheries in the marine ecosystem, calls for the protection of vulnerable marine ecosystems (VME from destructive fishing practices. Subsequently, the Food and Agriculture Organization (FAO produced guidelines for identification of VME indicator species/taxa to assist in the implementation of the resolution, but recommended the development of case-specific operational definitions for their application. We applied kernel density estimation (KDE to research vessel trawl survey data from inside the fishing footprint of the Northwest Atlantic Fisheries Organization (NAFO Regulatory Area in the high seas of the northwest Atlantic to create biomass density surfaces for four VME indicator taxa: large-sized sponges, sea pens, small and large gorgonian corals. These VME indicator taxa were identified previously by NAFO using the fragility, life history characteristics and structural complexity criteria presented by FAO, along with an evaluation of their recovery trajectories. KDE, a non-parametric neighbour-based smoothing function, has been used previously in ecology to identify hotspots, that is, areas of relatively high biomass/abundance. We present a novel approach of examining relative changes in area under polygons created from encircling successive biomass categories on the KDE surface to identify "significant concentrations" of biomass, which we equate to VMEs. This allows identification of the VMEs from the broader distribution of the species in the study area. We provide independent assessments of the VMEs so identified using underwater images, benthic sampling with other gear types (dredges, cores, and/or published species distribution models of probability of occurrence, as available. For each VME indicator taxon we provide a brief review of their ecological function which will be important in future assessments of significant adverse impact on these habitats here

  8. Conventional measurements of GFR using {sup 51}Cr-EDTA overestimate true renal clearance by 10 percent

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Amelia E.B.; Park-Holohan, So-Jin; Blake, Glen M.; Fogelman, Ignac [Department of Nuclear Medicine, Guy' s Hospital, St Thomas Street, London, SE1 9RT (United Kingdom)


    It is widely believed that measurement of the area under the plasma clearance curve (AUC) following a single intravenous injection of chromium-51 labelled ethylene diamine tetra-acetic acid ({sup 51}Cr-EDTA) is a gold standard method for determining glomerular filtration rate (GFR). However, there are reports that {sup 51}Cr-EDTA may have a significant extrarenal clearance. The aim of this study was to identify the non-renal component of {sup 51}Cr-EDTA plasma clearance contributing to the AUC measurement of GFR. Seventy healthy postmenopausal women (mean age 60 years, range 45-79 years) were injected with 3 MBq {sup 51}Cr-EDTA and 0.25 MBq iodine-125 labelled human serum albumin and 11 blood samples taken between 0 and 4 h through an indwelling venous cannula. For the first 21 subjects, two complete urine collections were made 0-2 h and 2-4 h after injection, and for the final 49 patients, four 1-h urine collections were made. The mean {sup 51}Cr-EDTA total plasma clearance was 84 ml/min (range 50-132 ml/min). The mean ratio (SEM) of urine to total clearance determined from the cumulative 1-, 2-, 3- and 4-h data was 0.903 (0.018), 0.891 (0.013), 0.898 (0.011) and 0.899 (0.010) respectively and remained constant despite the mean urine concentration decreasing from 122% to 15%/litre during this period. A least squares fit to data from the 238 individual urine collections was used to determine the fraction of the total plasma clearance attributable to renal clearance, {alpha}{sub 0}, and the residual urine volume, {delta}V. The results were {alpha}{sub 0}=0.910 (95% CI: 0.889-0.932) and {delta}V=14 ml (95% CI: -4 to +34 ml). The overestimation of the true renal clearance of {sup 51}Cr-EDTA by the AUC method is believed to be due to the failure of the plasma clearance curve to reach the true terminal exponential by 2 h after injection as usually assumed. As a result, conventional measurements of GFR using {sup 51}Cr-EDTA overestimate the true renal clearance of tracer

  9. Significance of settling model structures and parameter subsets in modelling WWTPs under wet-weather flow and filamentous bulking conditions

    DEFF Research Database (Denmark)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen;


    Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks...... (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of ideal and non-ideal flow (dry and wet weather) and settling (good settling and bulking) boundary conditions on the sensitivity of WWTP model outputs to uncertainties intrinsic to the one-dimensional (1-D...... of settling parameters to the total variance of the key WWTP process outputs significantly depends on the influent flow and settling conditions. The magnitude of the impact is found to vary, depending on which type of 1-D SST model is used. Therefore, we identify and recommend potential parameter subsets...

  10. High-fat diet induces significant metabolic disorders in a mouse model of polycystic ovary syndrome. (United States)

    Lai, Hao; Jia, Xiao; Yu, Qiuxiao; Zhang, Chenglu; Qiao, Jie; Guan, Youfei; Kang, Jihong


    Polycystic ovary syndrome (PCOS) is the most common female endocrinopathy associated with both reproductive and metabolic disorders. Dehydroepiandrosterone (DHEA) is currently used to induce a PCOS mouse model. High-fat diet (HFD) has been shown to cause obesity and infertility in female mice. The possible effect of an HFD on the phenotype of DHEA-induced PCOS mice is unknown. The aim of the present study was to investigate both reproductive and metabolic features of DHEA-induced PCOS mice fed a normal chow or a 60% HFD. Prepubertal C57BL/6 mice (age 25 days) on the normal chow or an HFD were injected (s.c.) daily with the vehicle sesame oil or DHEA for 20 consecutive days. At the end of the experiment, both reproductive and metabolic characteristics were assessed. Our data show that an HFD did not affect the reproductive phenotype of DHEA-treated mice. The treatment of HFD, however, caused significant metabolic alterations in DHEA-treated mice, including obesity, glucose intolerance, dyslipidemia, and pronounced liver steatosis. These findings suggest that HFD induces distinct metabolic features in DHEA-induced PCOS mice. The combined DHEA and HFD treatment may thus serve as a means of studying the mechanisms involved in metabolic derangements of this syndrome, particularly in the high prevalence of hepatic steatosis in women with PCOS.

  11. Significance of model credibility in estimating climate projection distributions for regional hydroclimatological risk assessments (United States)

    Brekke, L.D.; Dettinger, M.D.; Maurer, E.P.; Anderson, M.


    Ensembles of historical climate simulations and climate projections from the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset were investigated to determine how model credibility affects apparent relative scenario likelihoods in regional risk assessments. Methods were developed and applied in a Northern California case study. An ensemble of 59 twentieth century climate simulations from 17 WCRP CMIP3 models was analyzed to evaluate relative model credibility associated with a 75-member projection ensemble from the same 17 models. Credibility was assessed based on how models realistically reproduced selected statistics of historical climate relevant to California climatology. Metrics of this credibility were used to derive relative model weights leading to weight-threshold culling of models contributing to the projection ensemble. Density functions were then estimated for two projected quantities (temperature and precipitation), with and without considering credibility-based ensemble reductions. An analysis for Northern California showed that, while some models seem more capable at recreating limited aspects twentieth century climate, the overall tendency is for comparable model performance when several credibility measures are combined. Use of these metrics to decide which models to include in density function development led to local adjustments to function shapes, but led to limited affect on breadth and central tendency, which were found to be more influenced by 'completeness' of the original ensemble in terms of models and emissions pathways. ?? 2007 Springer Science+Business Media B.V.

  12. More Use of Peritoneal Dialysis Gives Significant Savings: A Systematic Review and Health Economic Decision Model (United States)

    Pike, Eva; Hamidi, Vida; Ringerike, Tove; Wisloff, Torbjorn; Klemp, Marianne


    Background Patients with end-stage renal disease (ESRD) are in need of renal replacement therapy as dialysis and/or transplantation. The prevalence of ESRD and, thus, the need for dialysis are constantly growing. The dialysis modalities are either peritoneal performed at home or hemodialysis (HD) performed in-center (hospital or satellite) or home. We examined effectiveness and cost-effectiveness of HD performed at different locations (hospital, satellite, and home) and peritoneal dialysis (PD) at home in the Norwegian setting. Methods We conducted a systematic review for patients above 18 years with end-stage renal failure requiring dialysis in several databases and performed several meta-analyses of existing literature. Mortality and major complications that required were our main clinical outcomes. The quality of the evidence for each outcome was evaluated using GRADE. Cost-effectiveness was assessed by developing a probabilistic Markov model. The analysis was carried out from a societal perspective, and effects were expressed in quality-adjusted life-years. Uncertainties in the base-case parameter values were explored with a probabilistic sensitivity analysis. Scenario analyses were conducted by increasing the proportion of patients receiving PD with a corresponding reduction in HD patients in-center both for Norway and Europian Union. We assumed an annual growth rate of 4% in the number of dialysis patients, and a relative distribution between PD and HD in-center of 30% and 70%, respectively. Results From a societal perspective and over a 5-year time horizon, PD was the most cost-effective dialysis alternative. We found no significant difference in mortality between peritoneal and HD modalities. Our scenario analyses showed that a shift toward more patients on PD (as a first choice) with a corresponding reduction in HD in-center gave a saving over a 5-year period of 32 and 10,623 million EURO, respectively, for Norway and the European Union. Conclusions PD was

  13. Significant impacts of irrigation water sources and methods on modeling irrigation effects in the ACME Land Model

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Guoyong; Leung, Lai-Yung; Huang, Maoyi


    An irrigation module that considers both irrigation water sources and irrigation methods has been incorporated into the ACME Land Model (ALM). Global numerical experiments were conducted to evaluate the impacts of irrigation water sources and irrigation methods on the simulated irrigation effects. All simulations shared the same irrigation soil moisture target constrained by a global census dataset of irrigation amounts. Irrigation has large impacts on terrestrial water balances especially in regions with extensive irrigation. Such effects depend on the irrigation water sources: surface-water-fed irrigation leads to decreases in runoff and water table depth, while groundwater-fed irrigation increases water table depth, with positive or negative effects on runoff depending on the pumping intensity. Irrigation effects also depend significantly on the irrigation methods. Flood irrigation applies water in large volumes within short durations, resulting in much larger impacts on runoff and water table depth than drip and sprinkler irrigations. Differentiating the irrigation water sources and methods is important not only for representing the distinct pathways of how irrigation influences the terrestrial water balances, but also for estimating irrigation water use efficiency. Specifically, groundwater pumping has lower irrigation water use efficiency due to enhanced recharge rates. Different irrigation methods also affect water use efficiency, with drip irrigation the most efficient followed by sprinkler and flood irrigation. Our results highlight the importance of explicitly accounting for irrigation sources and irrigation methods, which are the least understood and constrained aspects in modeling irrigation water demand, water scarcity and irrigation effects in Earth System Models.

  14. Overestimation of the second time interval replaces time-shrinking when the difference between two adjacent time intervals increases

    Directory of Open Access Journals (Sweden)

    Yoshitaka eNakajima


    Full Text Available When the onsets of three successive sound bursts mark two adjacent time intervals, the second time interval can be underestimated when it is physically longer than the first time interval by up to 100 ms. This illusion, time-shrinking, is very stable when the first time interval is 200 ms or shorter (Nakajima et al., 2004, Perception, 33. Time-shrinking had been considered a kind of perceptual assimilation to make the first and the second time interval more similar to each other. Here we investigated whether the underestimation of the second time interval was replaced by an overestimation if the physical difference between the neighboring time intervals was too large for the assimilation to take place; this was a typical situation in which a perceptual contrast could be expected. Three experiments to measure the overestimation/underestimation of the second time interval by the method of adjustment were conducted. The first time interval was varied from 40 to 280 ms, and such overestimations indeed took place when the first time interval was 80-280 ms. The overestimations were robust when the second time interval was longer than the first time interval by 240 ms or more, and the magnitude of the overestimation was larger than 100 ms in some conditions. Thus, a perceptual contrast to replace time-shrinking was established. An additional experiment indicated that this contrast did not affect the perception of the first time interval substantially: The contrast in the present conditions seemed unilateral.

  15. Heat stress is overestimated in climate impact studies for irrigated agriculture (United States)

    Siebert, Stefan; Webber, Heidi; Zhao, Gang; Ewert, Frank


    Climate change will increase the number and severity of heat waves, and is expected to negatively affect crop yields. Here we show for wheat and maize across Europe that heat stress is considerably reduced by irrigation due to surface cooling for both current and projected future climate. We demonstrate that crop heat stress impact assessments should be based on canopy temperature because simulations with air temperatures measured at standard weather stations cannot reproduce differences in crop heat stress between irrigated and rainfed conditions. Crop heat stress was overestimated on irrigated land when air temperature was used with errors becoming larger with projected climate change. Corresponding errors in mean crop yield calculated across Europe for baseline climate 1984-2013 of 0.2 Mg yr-1 (2%) and 0.6 Mg yr-1 (5%) for irrigated winter wheat and irrigated grain maize, respectively, would increase to up to 1.5 Mg yr-1 (16%) for irrigated winter wheat and 4.1 Mg yr-1 (39%) for irrigated grain maize, depending on the climate change projection/GCM combination considered. We conclude that climate change impact assessments for crop heat stress need to account explicitly for the impact of irrigation.

  16. Phytoestrogens in milk: Overestimations caused by contamination of the hydrolytic enzyme used during sample extraction. (United States)

    Bláhová, L; Kohoutek, J; Procházková, T; Prudíková, M; Bláha, L


    Isoflavones are natural phytoestrogens with antioxidant and endocrine-disrupting potencies. Monitoring of their levels is important to ensure the high quality and safety of food, milk, and dairy products. The efficiency and accuracy of phytoestrogen analyses in complex matrices such as milk depend on the extraction procedure, which often uses hydrolysis by means of the β-glucuronidase/sulfatase enzyme originating from Helix pomatia. The present study reveals that the commercially available hydrolytic enzyme is contaminated by several phytoestrogen isoflavones (genistein, daidzein, formononetin, and biochanin A) and their metabolite equol, as well as flavones (naringenin and apigenin) and coumestrol. We show that the concentrations of daidzein and genistein in the enzyme could have impaired the results of analyses of the main isoflavones in several previously published studies. Of 8 analyzed compounds, only equol was confirmed in the present study and it serves as a reliable marker of phytoestrogens originating from cow feed. Critical reassessment of phytoestrogen concentrations in milk is needed because several previously published studies might have overestimated the concentrations depending on the extraction procedure used.

  17. Thermochemical remanence in single-domain particle assemblages can lead to paleointensity overestimates (United States)

    Fabian, K.


    Single-domain (SD) particle ensembles are the best studied systems in rock magnetism. Yet, even for this simple system, a complete theoretical treatment of the acquisition of thermochemical remanent magnetization (TCRM) is missing. Based on the SD theory of chemical-remanent magnetization (CRM), it is generally taken for granted that TCRM acquisition is less efficient than acquisition of a thermoremanent magnetization (TRM), and that consequently the paleofield intensity is inevitably underestimated when a TCRM is interpreted as a TRM. Here it is shown that this conclusion holds only when a continuous chemical change (e.g. grain growth) takes place during remanence blocking. In cases where an initial TRM, at a later time and at lower temperature, is modified by chemical processes, the final TCRM can result in considerable paleofield overestimation when interpreted as a TRM. This is demonstrated for two different scenarios. First, partial grain dissolution after TRM acquisition and second, low-temperature oxidation. These mechanisms are not unlikely to occur in nature, and numerical experiments indicate that both would lead to perfectly straight Arai plots, which make such SD TCRMs indistinguishable from true TRMs in the Thellier experiment.

  18. Alcohol consumption and rates of cancer screening: Is cancer risk overestimated? (United States)

    Mu, Lin; Mukamal, Kenneth J


    Alcohol consumption in moderation has been associated with incident breast and colorectal cancer. Whether these associations may be overestimated by more intensive screening among moderate consumers is unknown. This study examines the associations of alcohol consumption with cancer screening. In six iterations (2002-2012) of the Behavioral Risk Factor Surveillance System, a telephone survey of US adults conducted by the Centers for Disease Control and Prevention, participants reported their alcohol use and recent screening for several cancers. We assessed whether alcohol use was associated with breast, cervical, and colorectal cancer screening after sample-weighted adjustment for sociodemographic and healthcare utilization factors. Among 2,191,483 survey respondents, 80.5 % (weighted prevalence) of eligible individuals reported having an up-to-date mammogram, 87.7 % having a Pap test, and 56.8 % having a colonoscopy/sigmoidoscopy. For all breast, cervical, and colorectal cancers, moderate consumers were more likely to report screening (84.7, 91.2, 61.1 %) than non-consumers, even after multivariate adjustment (adjusted prevalence ratios 1.04, 1.04, 1.07; p cancer screening. In the USA, moderate consumers consistently report a greater likelihood of breast, cervical, and colorectal cancer screening than do non-consumers. Given the likelihood of overdiagnosis, further study of alcohol consumption and cancer should include cancer-specific mortality, which is less sensitive to differences in screening and detection.

  19. Innovations in individual feature history management - The significance of feature-based temporal model (United States)

    Choi, J.; Seong, J.C.; Kim, B.; Usery, E.L.


    A feature relies on three dimensions (space, theme, and time) for its representation. Even though spatiotemporal models have been proposed, they have principally focused on the spatial changes of a feature. In this paper, a feature-based temporal model is proposed to represent the changes of both space and theme independently. The proposed model modifies the ISO's temporal schema and adds new explicit temporal relationship structure that stores temporal topological relationship with the ISO's temporal primitives of a feature in order to keep track feature history. The explicit temporal relationship can enhance query performance on feature history by removing topological comparison during query process. Further, a prototype system has been developed to test a proposed feature-based temporal model by querying land parcel history in Athens, Georgia. The result of temporal query on individual feature history shows the efficiency of the explicit temporal relationship structure. ?? Springer Science+Business Media, LLC 2007.

  20. Standard Genotyping Overestimates Transmission of Mycobacterium tuberculosis among Immigrants in a Low-Incidence Country. (United States)

    Stucki, David; Ballif, Marie; Egger, Matthias; Furrer, Hansjakob; Altpeter, Ekkehardt; Battegay, Manuel; Droz, Sara; Bruderer, Thomas; Coscolla, Mireia; Borrell, Sonia; Zürcher, Kathrin; Janssens, Jean-Paul; Calmy, Alexandra; Mazza Stalder, Jesica; Jaton, Katia; Rieder, Hans L; Pfyffer, Gaby E; Siegrist, Hans H; Hoffmann, Matthias; Fehr, Jan; Dolina, Marisa; Frei, Reno; Schrenzel, Jacques; Böttger, Erik C; Gagneux, Sebastien; Fenner, Lukas


    Immigrants from regions with a high incidence of tuberculosis (TB) are a risk group for TB in low-incidence countries such as Switzerland. In a previous analysis of a nationwide collection of 520 Mycobacterium tuberculosis isolates from 2000 to 2008, we identified 35 clusters comprising 90 patients based on standard genotyping (24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat [MIRU-VNTR] typing and spoligotyping). Here, we used whole-genome sequencing (WGS) to revisit these transmission clusters. Genome-based transmission clusters were defined as isolate pairs separated by ≤12 single nucleotide polymorphisms (SNPs). WGS confirmed 17/35 (49%) MIRU-VNTR typing clusters; the other 18 clusters contained pairs separated by >12 SNPs. Most transmission clusters (3/4) of Swiss-born patients were confirmed by WGS, as opposed to 25% (4/16) of the clusters involving only foreign-born patients. The overall clustering proportion was 17% (90 patients; 95% confidence interval [CI], 14 to 21%) by standard genotyping but only 8% (43 patients; 95% CI, 6 to 11%) by WGS. The clustering proportion was 17% (67/401; 95% CI, 13 to 21%) by standard genotyping and 7% (26/401; 95% CI, 4 to 9%) by WGS among foreign-born patients and 19% (23/119; 95% CI, 13 to 28%) and 14% (17/119; 95% CI, 9 to 22%), respectively, among Swiss-born patients. Using weighted logistic regression, we found weak evidence of an association between birth origin and transmission (adjusted odds ratio of 2.2 and 95% CI of 0.9 to 5.5 comparing Swiss-born patients to others). In conclusion, standard genotyping overestimated recent TB transmission in Switzerland compared to WGS, particularly among immigrants from regions with a high TB incidence, where genetically closely related strains often predominate. We recommend the use of WGS to identify transmission clusters in settings with a low incidence of TB.

  1. Significance of hydrological model choice and land use changes when doing climate change impact assessment (United States)

    Bjørnholt Karlsson, Ida; Obel Sonnenborg, Torben; Refsgaard, Jens Christian; Høgh Jensen, Karsten


    Uncertainty in impact studies arises both from Global Climate Models (GCM), emission projections, statistical downscaling, Regional Climate Models (RCM), hydrological models and calibration techniques (Refsgaard et al. 2013). Some of these uncertainties have been evaluated several times in the literature; however few studies have investigated the effect of hydrological model choice on the assessment results (Boorman & Sefton 1997; Jiang et al. 2007; Bastola et al. 2011). These studies have found that model choice results in large differences, up to 70%, in the predicted discharge changes depending on the climate input. The objective of the study is to investigate the impact of climate change on hydrology of the Odense catchment, Denmark both in response to (a) different climate projections (GCM-RCM combinations); (b) different hydrological models and (c) different land use scenarios. This includes: 1. Separation of the climate model signal; the hydrological model signal and the land use signal 2. How do the different hydrological components react under different climate and land use conditions for the different models 3. What land use scenario seems to provide the best adaptation for the challenges of the different future climate change scenarios from a hydrological perspective? Four climate models from the ENSEMBLES project (Hewitt & Griggs 2004): ECHAM5 - HIRHAM5, ECHAM5 - RCA3, ARPEGE - RM5.1 and HadCM3 - HadRM3 are used, assessing the climate change impact in three periods: 1991-2010 (present), 2041-2060 (near future) and 2081-2100 (far future). The four climate models are used in combination with three hydrological models with different conceptual layout: NAM, SWAT and MIKE SHE. Bastola, S., C. Murphy and J. Sweeney (2011). "The role of hydrological modelling uncertainties in climate change impact assessments of Irish river catchments." Advances in Water Resources 34: 562-576. Boorman, D. B. and C. E. M. Sefton (1997). "Recognising the uncertainty in the

  2. Significance of uncertainties derived from settling tank model structure and parameters on predicting WWTP performance - A global sensitivity analysis study

    DEFF Research Database (Denmark)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen


    Uncertainty derived from one of the process models – such as one-dimensional secondary settling tank (SST) models – can impact the output of the other process models, e.g., biokinetic (ASM1), as well as the integrated wastewater treatment plant (WWTP) models. The model structure and parameter...... uncertainty of settler models can therefore propagate, and add to the uncertainties in prediction of any plant performance criteria. Here we present an assessment of the relative significance of secondary settling model performance in WWTP simulations. We perform a global sensitivity analysis (GSA) based....... The outcome of this study contributes to a better understanding of uncertainty in WWTPs, and explicitly demonstrates the significance of secondary settling processes that are crucial elements of model prediction under dry and wet-weather loading conditions....

  3. Significantly improved HIV inhibitor efficacy prediction employing proteochemometric models generated from antivirogram data.

    Directory of Open Access Journals (Sweden)

    Gerard J P van Westen

    Full Text Available Infection with HIV cannot currently be cured; however it can be controlled by combination treatment with multiple anti-retroviral drugs. Given different viral genotypes for virtually each individual patient, the question now arises which drug combination to use to achieve effective treatment. With the availability of viral genotypic data and clinical phenotypic data, it has become possible to create computational models able to predict an optimal treatment regimen for an individual patient. Current models are based only on sequence data derived from viral genotyping; chemical similarity of drugs is not considered. To explore the added value of chemical similarity inclusion we applied proteochemometric models, combining chemical and protein target properties in a single bioactivity model. Our dataset was a large scale clinical database of genotypic and phenotypic information (in total ca. 300,000 drug-mutant bioactivity data points, 4 (NNRTI, 8 (NRTI or 9 (PI drugs, and 10,700 (NNRTI 10,500 (NRTI or 27,000 (PI mutants. Our models achieved a prediction error below 0.5 Log Fold Change. Moreover, when directly compared with previously published sequence data, derived models PCM performed better in resistance classification and prediction of Log Fold Change (0.76 log units versus 0.91. Furthermore, we were able to successfully confirm both known and identify previously unpublished, resistance-conferring mutations of HIV Reverse Transcriptase (e.g. K102Y, T216M and HIV Protease (e.g. Q18N, N88G from our dataset. Finally, we applied our models prospectively to the public HIV resistance database from Stanford University obtaining a correct resistance prediction rate of 84% on the full set (compared to 80% in previous work on a high quality subset. We conclude that proteochemometric models are able to accurately predict the phenotypic resistance based on genotypic data even for novel mutants and mixtures. Furthermore, we add an applicability domain to

  4. 75 FR 29587 - Notice of Availability of Revised Model Proposed No Significant Hazards Consideration... (United States)


    ... of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC, 20555-0001... Processes Branch, Division of Policy and Rulemaking, Office of Nuclear Reactor Regulation. Revised Model... with the confidence in the ability of the fission product barriers (i.e., fuel cladding,...

  5. Significant Term List Based Metadata Conceptual Mining Model for Effective Text Clustering

    Directory of Open Access Journals (Sweden)

    J. Janet


    Full Text Available As the engineering world are growing fast, the usage of data for the day to day activity of the engineering industry also growing rapidly. In order to handle and to find the hidden knowledge from huge data storage, data mining is very helpful right now. Text mining, network mining, multimedia mining, trend analysis are few applications of data mining. In text mining, there are variety of methods are proposed by many researchers, even though high precision, better recall are still is a critical issues. In this study, text mining is focused and conceptual mining model is applied for improved clustering in the text mining. The proposed work is termed as Meta data Conceptual Mining Model (MCMM, is validated with few world leading technical digital library data sets such as IEEE, ACM and Scopus. The performance derived as precision, recall are described in terms of Entropy, F-Measure which are calculated and compared with existing term based model and concept based mining model.

  6. Significance of Kinetics for Sorption on Inorganic Colloids: Modeling and Data Interpretation Issues (United States)

    Painter, S.; Cvetkovic, V.; Pickett, D.; Turner, D.


    Irreversible or slowly reversible attachment to inorganic colloids is a process that may enhance radionuclide transport in the environment. An understanding of sorption kinetics is critical in evaluating this process. A two-site kinetic model for sorption on inorganic colloids is developed and used to evaluate laboratory data. This model was developed as an alternative to the equilibrium colloid sorption model employed by the U.S. Department of Energy (DOE) in their performance assessment for the proposed repository for high-level nuclear waste at Yucca Mountain, Nevada. The model quantifies linear first-order sorption on two types of hypothetical sites (fast and slow) characterized by two pairs of rates (forward and reverse). We use the model to explore data requirements for long-term predictive calculations and to evaluate laboratory kinetic sorption data of Lu et al. Five batch sorption data sets are considered with Pu(V) as the tracer and montmorillonite, hematite, silica, and smectite as colloids. Using asymptotic results applicable on the 240 hour time-scale of the experiments, a robust estimation procedure is developed for the fast-site partitioning coefficient and the slow forward rate. The estimated range for the partition coefficient is 1.1-76 L/g; the range for the slow forward rate is 0.0017-0.02 L/h. Comparison of one-site and two-site sorption interpretations reveals the difficulty in discriminating between the two models for montmorillonite and to a lesser extent for hematite. For silica and smectite the two-site model clearly provides a better representation of the data as compared with a single site model. Kinetic data for silica are available for different colloid concentrations (0.2 g/L and 1.0 g/L). For the range of experimental conditions considered, the forward rate appears to be independent of the colloid concentration. The slow reverse rate cannot be estimated on the time scale of the experiments; we estimate the detection limits for the

  7. An Ecological-Transactional Model of Significant Risk Factors for Child Psychopathology in Outer Mongolia (United States)

    Kohrt, Holbrook E.; Kohrt, Brandon A.; Waldman, Irwin; Saltzman, Kasey; Carrion, Victor G.


    The present study examined significant risk factors, including child maltreatment, for child psychopathology in a cross-cultural setting. Ninety-nine Mongolian boys, ages 3-10 years, were assessed. Primary caregivers (PCG) completed structured interviews including the Emory Combined Rating Scale (ECRS) and the Mood and Feelings Questionnaire…

  8. Magnitude, modeling and significance of swelling and shrinkage processes in clay soils.

    NARCIS (Netherlands)

    Bronswijk, J.J.B.


    The dynamic process of swelling and shrinkage in clay soils has significant practical consequences, such as the rapid transport of water and solutes via shrinkage cracks to the subsoil, and the destruction of buildings and roads on clay soils. In order to develop measuring methods and computer simul

  9. Efficacy of surgical hand scrub products based on chlorhexidine is largely overestimated without neutralizing agents in the sampling fluid. (United States)

    Kampf, Günter; Reichel, Mirja; Hollingsworth, Angela; Bashir, Muhammad


    Surgical hand antiseptics often contain chlorhexidine gluconate (CHG). There are doubts that the full effect measured for these products might only be achieved after sampling because of a lack of valid neutralizing agents (NAs) in the sampling fluid. We measured the efficacy of Avagard CHG and Hibiclens for 11 applications over 5 days according to the manufacturers' instructions. NAs were added to the sampling fluid and the dilution fluid (group 1) or to only the dilution fluid (group 2). In a third group, NAs were added to the dilution fluid only, and cream was applied after the final scrub on days 1 to 4. Neutralization was validated according to American Society for Testing and Materials International standard 1054 using Staphylococcus epidermidis. When NAs were not added to the sampling fluid, both products were very effective, with a mean log(10) reduction in flora of 3.32 ± 0.53 for Avagard and 3.68 ± 0.52 for Hibiclens on day 5. When NAs were included in the sampling fluid, however, the immediate efficacy was significantly lower, at 2.75 ± 0.55 and 3.14 ± 0.50, respectively. A lack of NAs in the sampling fluid resulted in overestimation of efficacy by a factor of between 0.3 and 1.1 log(10). Efficacy studies carried out without NAs in the sampling fluid for products with CHG should be critically assessed. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  10. Symptomatic malaria diagnosis overestimate malaria prevalence, but underestimate anaemia burdens in children: results of a follow up study in Kenya. (United States)

    Choge, Joseph K; Magak, Ng'wena G; Akhwale, Willis; Koech, Julius; Ngeiywa, Moses M; Oyoo-Okoth, Elijah; Esamai, Fabian; Osano, Odipo; Khayeka-Wandabwa, Christopher; Kweka, Eliningaya J


    The commonly accepted gold standard diagnostic method for detecting malaria is a microscopic reading of Giemsa-stained blood films. However, symptomatic diagnosis remains the basis of therapeutic care for the majority of febrile patients in malaria endemic areas. This study aims to compare the discrepancy in malaria and anaemia burdens between symptomatic diagnosed patients with those diagnosed through the laboratory. Data were collected from Western Kenya during a follow-up study of 887 children with suspected cases of malaria visiting the health facilities. In the laboratory, blood samples were analysed for malaria parasite and haemoglobin levels. Differences in malaria prevalence between symptomatic diagnosis and laboratory diagnosis were analysed by Chi-square test. Bayesian probabilities were used for the approximation of the malaria and anaemia burdens. Regression analysis was applied to: (1) determine the relationships between haemoglobin levels, and malaria parasite density and (2) relate the prevalence of anaemia and the prevalence of malaria. The prevalence of malaria and anaemia ranged from 10% to 34%, being highest during the rainy seasons. The predominant malaria parasite was P. falciparum (92.3%), which occurred in higher density in children aged 2‒5 years. Fever, high temperature, sweating, shivering, vomiting and severe headache symptoms were associated with malaria during presumptive diagnosis. After conducting laboratory diagnosis, lower malaria prevalence was reported among the presumptively diagnosed patients. Surprisingly, there were no attempts to detect anaemia in the same cohort. There was a significant negative correlation between Hb levels and parasite density. We also found a positive correlation between the prevalence of anaemia and the prevalence of malaria after laboratory diagnosis indicating possible co-occurrence of malaria and anaemia. Symptomatic diagnosis of malaria overestimates malaria prevalence, but underestimates the

  11. Significance of different animal species in experimental models for in vivo investigations of hematopoiesis

    Directory of Open Access Journals (Sweden)

    Kovačević-Filipović Milica


    Full Text Available Numerous discoveries in medicine are results of experiments on different animal species. The most frequently used animals in hematopoiesis investigations are laboratory mice and rats, but so-called big animals, such as pigs, sheep, cats, dogs, and monkeys, evolution-wise closer to humans have a place in experimental hematology as well. The specific problematics of a certain animal specie can lead to fundamental knowledge on certain aspects of the process of hematopoiesis end the biology of stem cells in hematopoiesis. Furthermore, comparative investigations of certain phenomena in different species help in the recognition of the general rules in the living world. In the area f preclinicalinvesti- gations, animal models are an inevitable step in studies of transplantation biology of stem cells in hematopoiesis, as well as in studies of biologically active molecules which have an effect on the hematopoietic system. Knowledge acquired on animal models is applied in both human and veterinary medicine.

  12. Recent advances in mechanical characterisation of biofilm and their significance for material modelling. (United States)

    Böl, Markus; Ehret, Alexander E; Bolea Albero, Antonio; Hellriegel, Jan; Krull, Rainer


    In recent years, the advances in microbiology show that biofilms are structurally complex, dynamic and adaptable systems including attributes of multicellular organisms and miscellaneous ecosystems. One may distinguish between beneficial and harmful biofilms appearing in daily life as well as various industrial processes. In order to advance the growth of the former or prevent the latter type of biofilm, a detailed understanding of its properties is indispensable. Besides microbiological aspects, this concerns the determination of mechanical characteristics, which provides the basis for material modelling. In the present paper the existing experimental methods that have been proposed since the 1980s are reviewed and critically discussed with respect to their usefulness and applicability to develop numerical modelling approaches.

  13. Development of the PCAD Model to Assess Biological Significance of Acoustic Disturbance (United States)


    mother-calf separation as a function of body mass index ( BMI ) and proportion lipid in blubber. We have also quantified the relationship between those...the approach. This is best accomplished by selecting species that are as similar as possible to target species and are also extremely well-studied...We identified northern elephant seals and Atlantic bottlenose dolphins as the best species to parameterize the PCAD model. These species represent

  14. Significance of genetic information in risk assessment and individual classification using silicosis as a case model

    Energy Technology Data Exchange (ETDEWEB)

    McCanlies, E.; Landsittel, D.P.; Yucesoy, B.; Vallyathan, V.; Luster, M.L.; Sharp, D.S. [NIOSH, Morgantown, WV (United States)


    Over the last decade the role of genetic data in epidemiological research has expanded considerably. The authors recently published a case-control study that evaluated the interaction between silica exposure and minor variants in the genes coding for interleukin-1alpha. (IL-1alpha), interleukin-1 receptor antagonist (IL-1RA) and tumor necrosis factor alpha (TNFalpha) as risk factors associated with silicosis, a fibrotic lung disease. In contrast, this report uses data generated from these studies to illustrate the utility of genetic information for the purposes of risk assessment and clinical prediction. Specifically, this study addresses how, given a known exposure, genetic information affects the characterization of risk groups. Relative operating characteristic (ROC) curves were then used to determine the impact of genetic information on individual classification. Logistic regression modeling procedures were used to estimate the predicted probability of developing silicosis. This probability was then used to construct predicted risk deciles, first for a model with occupational exposure only and then for a model containing occupational exposure and genetic main effects and interactions. The results indicate that genetic information plays a valuable role in effectively characterizing risk groups and mechanisms of disease operating in a substantial proportion of the population. However, in the case of fibrotic lung disease caused by silica exposure, information about the presence or absence of the minor variants of IL-1alpha, IL-1RA and TNFalpha is unlikely to be a useful tool for individual classification.

  15. Breast cancer-associated metastasis is significantly increased in a model of autoimmune arthritis (United States)

    Das Roy, Lopamudra; Pathangey, Latha B; Tinder, Teresa L; Schettini, Jorge L; Gruber, Helen E; Mukherjee, Pinku


    Introduction Sites of chronic inflammation are often associated with the establishment and growth of various malignancies including breast cancer. A common inflammatory condition in humans is autoimmune arthritis (AA) that causes inflammation and deformity of the joints. Other systemic effects associated with arthritis include increased cellular infiltration and inflammation of the lungs. Several studies have reported statistically significant risk ratios between AA and breast cancer. Despite this knowledge, available for a decade, it has never been questioned if the site of chronic inflammation linked to AA creates a milieu that attracts tumor cells to home and grow in the inflamed bones and lungs which are frequent sites of breast cancer metastasis. Methods To determine if chronic inflammation induced by autoimmune arthritis contributes to increased breast cancer-associated metastasis, we generated mammary gland tumors in SKG mice that were genetically prone to develop AA. Two breast cancer cell lines, one highly metastatic (4T1) and the other non-metastatic (TUBO) were used to generate the tumors in the mammary fat pad. Lung and bone metastasis and the associated inflammatory milieu were evaluated in the arthritic versus the non-arthritic mice. Results We report a three-fold increase in lung metastasis and a significant increase in the incidence of bone metastasis in the pro-arthritic and arthritic mice compared to non-arthritic control mice. We also report that the metastatic breast cancer cells augment the severity of arthritis resulting in a vicious cycle that increases both bone destruction and metastasis. Enhanced neutrophilic and granulocytic infiltration in lungs and bone of the pro-arthritic and arthritic mice and subsequent increase in circulating levels of proinflammatory cytokines, such as macrophage colony stimulating factor (M-CSF), interleukin-17 (IL-17), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), and tumor necrosis factor

  16. Support for significant evolutions of the user data model in ROOT files

    Energy Technology Data Exchange (ETDEWEB)

    Canal, Ph; Russo, P [Fermilab, Batavia, IL (United States); Brun, R; Janyst, L [CERN, Geneva (Switzerland); Fine, V; Lauret, J, E-mail: pcanal@fnal.go [Brookhaven National Laboratory, Upton, NY (United States)


    One of the main strengths of ROOT input and output (I/O) is its inherent support for schema evolution. Two distinct modes are supported, one manual via a hand coded streamer function and one fully automatic via the ROOT StreamerInfo. One draw back of the streamer functions is that they are not usable by TTree objects in split mode. Until now, the user could not customize the automatic schema evolution mechanism and the only mechanism to go beyond the default rules was to revert to using the streamer function. In ROOT 5.22/00, we introduced a new mechanism which allows user provided extensions of the automatic schema evolution that can be used in object-wise, member-wise and split modes. This paper will describe the many possibilities ranging from the simple assignment of transient members to the complex reorganization of the user's object model.

  17. Trait impressions as overgeneralized responses to adaptively significant facial qualities: evidence from connectionist modeling. (United States)

    Zebrowitz, Leslie A; Fellous, Jean-Marc; Mignault, Alain; Andreoletti, Carrie


    Connectionist modeling experiments tested anomalous-face and baby-face overgeneralization hypotheses proposed to explain consensual trait impressions of faces. Activation of a neural network unit trained to respond to anomalous faces predicted impressions of normal adult faces varying in attractiveness as well as several elderly stereotypes. Activation of a neural network unit trained to respond to babies' faces predicted impressions of adults varying in babyfaceness as well as 1 elderly stereotype. Thus, similarities of normal adult faces to anomalous faces or babies' faces contribute to impressions of them quite apart from knowledge of overlapping social stereotypes. The evolutionary importance of appropriate responses to unfit individuals or babies is presumed to produce a strong response preparedness that is overgeneralized to faces resembling the unfit or babies.

  18. Mouse models of lipodystrophy and their significance in understanding fat regulation. (United States)

    Rochford, Justin J


    Adipose tissue plays a critical role in human metabolic health. This is most dramatically illustrated by the severe metabolic disease that occurs in syndromes of lipodystrophy where individuals fail to develop or maintain appropriate adipose tissue mass. The most severe form of this disorder is congenital generalized lipodystrophy (CGL). Individuals with CGL have a striking paucity of adipose tissue and typically display severe metabolic disease with insulin resistance and dyslipidemia. Understanding of the metabolic consequences of lipodystrophies and their underlying molecular mechanisms will provide new information regarding the development and function of human adipose tissue. Mouse models of these conditions offer key resources to investigate this in vivo. Adipocyte dysfunction is believed to underlie the development of metabolic disease in obesity. Hence, understanding how one might beneficially manipulate adipose tissue by studying genes whose disruption causes lipodystrophy is likely to suggest novel means to improve metabolic health in common obesity.

  19. Support for significant evolutions of the user data model in ROOT files

    Energy Technology Data Exchange (ETDEWEB)

    Canal, P.; /Fermilab; Brun, R.; /CERN; Fine, V.; /Brookhaven; Janyst, L.; /CERN; Lauret, J.; /Brookhaven; Russo, P.; /Fermilab


    One of the main strengths of ROOT input and output (I/O) is its inherent support for schema evolution. Two distinct modes are supported, one manual via a hand coded streamer function and one fully automatic via the ROOT StreamerInfo. One draw back of the streamer functions is that they are not usable by TTree objects in split mode. Until now, the user could not customize the automatic schema evolution mechanism and the only mechanism to go beyond the default rules was to revert to using the streamer function. In ROOT 5.22/00, we introduced a new mechanism which allows user provided extensions of the automatic schema evolution that can be used in object-wise, member-wise and split modes. This paper will describe the many possibilities ranging from the simple assignment of transient members to the complex reorganization of the user's object model.

  20. Preconditioning Provides Neuroprotection in Models of CNS Disease: Paradigms and Clinical Significance (United States)

    Stetler, R. Anne; Leak, Rehana K.; Gan, Yu; Li, Peiying; Hu, Xiaoming; Jing, Zheng; Chen, Jun; Zigmond, Michael J.; Gao, Yanqin


    Preconditioning is a phenomenon in which brief episodes of a sublethal insult induce robust protection against subsequent lethal injuries. Preconditioning has been observed in multiple organisms and can occur in the brain as well as other tissues. Extensive animal studies suggest that the brain can be preconditioned to resist acute injuries, such as ischemic stroke, neonatal hypoxia/ischemia, trauma, and agents that are used in models of neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease. Effective preconditioning stimuli are numerous and diverse, ranging from transient ischemia, hypoxia, hyperbaric oxygen, hypothermia and hyperthermia, to exposure to neurotoxins and pharmacological agents. The phenomenon of “cross-tolerance,” in which a sublethal stress protects against a different type of injury, suggests that different preconditioning stimuli may confer protection against a wide range of injuries. Research conducted over the past few decades indicates that brain preconditioning is complex, involving multiple effectors such as metabolic inhibition, activation of extra- and intracellular defense mechanisms, a shift in the neuronal excitatory/inhibitory balance, and reduction in inflammatory sequelae. An improved understanding of brain preconditioning should help us identify innovative therapeutic strategies that prevent or at least reduce neuronal damage in susceptible patients. In this review, we focus on the experimental evidence of preconditioning in the brain and systematically survey the models used to develop paradigms for neuroprotection, and then discuss the clinical potential of brain preconditioning. In a subsequent components of this two-part series, we will discuss the cellular and molecular events that are likely to underlie these phenomena. PMID:24389580

  1. Thermophysical modeling of asteroids from WISE thermal infrared data - Significance of the shape model and the pole orientation uncertainties

    CERN Document Server

    Hanuš, Josef; Ďurech, Josef; Alí-Lagoa, Victor


    In the analysis of thermal infrared data of asteroids by means of thermophysical models (TPMs) it is a common practice to neglect the uncertainty of the shape model and the rotational state, which are taken as an input for the model. Here, we present a novel method of investigating the importance of the shape model and the pole orientation uncertainties in the thermophysical modeling - the varied shape TPM (VS-TPM). Our method uses optical photometric data to generate various shape models that map the uncertainty in the shape and the rotational state. The TPM procedure is then run for all these shape models. We apply the implementation of the classical TPM as well as our VS-TPM to the convex shape models of several asteroids together with their thermal infrared data acquired by the NASA's Wide-field Infrared Survey Explorer (WISE) and compare the results. These show that the uncertainties of the shape model and the pole orientation can be very important (e.g., for the determination of the thermal inertia) and...

  2. Towards the Significance of Decision Aid in Building Information Modeling (BIM Software Selection Process

    Directory of Open Access Journals (Sweden)

    Omar Mohd Faizal


    Full Text Available Building Information Modeling (BIM has been considered as a solution in construction industry to numerous problems such as delays, increased lead in times and increased costs. This is due to the concept and characteristic of BIM that will reshaped the way construction project teams work together to increase productivity and improve the final project outcomes (cost, time, quality, safety, functionality, maintainability, etc.. As a result, the construction industry has witnesses numerous of BIM software available in market. Each of this software has offers different function, features. Furthermore, the adoption of BIM required high investment on software, hardware and also training expenses. Thus, there is indentified that there is a need of decision aid for appropriated BIM software selection that fulfill the project needs. However, research indicates that there is limited study attempt to guide decision in BIM software selection problem. Thus, this paper highlight the importance of decision making and support for BIM software selection as it is vital to increase productivity, construction project throughout building lifecycle.

  3. Myriocin significantly increases the mortality of a non-mammalian model host during Candida pathogenesis.

    Directory of Open Access Journals (Sweden)

    Nadja Rodrigues de Melo

    Full Text Available Candida albicans is a major human pathogen whose treatment is challenging due to antifungal drug toxicity, drug resistance and paucity of antifungal agents available. Myrocin (MYR inhibits sphingosine synthesis, a precursor of sphingolipids, an important cell membrane and signaling molecule component. MYR also has dual immune suppressive and antifungal properties, potentially modulating mammalian immunity and simultaneously reducing fungal infection risk. Wax moth (Galleria mellonella larvae, alternatives to mice, were used to establish if MYR suppressed insect immunity and increased survival of C. albicans-infected insects. MYR effects were studied in vivo and in vitro, and compared alone and combined with those of approved antifungal drugs, fluconazole (FLC and amphotericin B (AMPH. Insect immune defenses failed to inhibit C. albicans with high mortalities. In insects pretreated with the drug followed by C. albicans inoculation, MYR+C. albicans significantly increased mortality to 93% from 67% with C. albicans alone 48 h post-infection whilst AMPH+C. albicans and FLC+C. albicans only showed 26% and 0% mortalities, respectively. MYR combinations with other antifungal drugs in vivo also enhanced larval mortalities, contrasting the synergistic antifungal effect of the MYR+AMPH combination in vitro. MYR treatment influenced immunity and stress management gene expression during C. albicans pathogenesis, modulating transcripts putatively associated with signal transduction/regulation of cytokines, I-kappaB kinase/NF-kappaB cascade, G-protein coupled receptor and inflammation. In contrast, all stress management gene expression was down-regulated in FLC and AMPH pretreated C. albicans-infected insects. Results are discussed with their implications for clinical use of MYR to treat sphingolipid-associated disorders.

  4. Overestimation of soil CO2 fluxes from closed chamber measurements at low atmospheric turbulence biases the diurnal pattern and the annual soil respiration budget

    DEFF Research Database (Denmark)

    Brændholt, Andreas; Larsen, Klaus Steenberg; Ibrom, Andreas


    including all data and it decreased with an increasing u⋆ filter threshold. Our results show that Rs was overestimated at low atmospheric turbulence throughout the year and that this overestimation considerably biased the diurnal pattern of Rs and led to an overestimation of the annual Rs budget. Thus we...... for correct estimation of annual Rs budgets. Acknowledgements: This study was funded by the free Danish Ministry for Research, Innovation and higher Education, the free Danish Research Council (DFF - 1323-00182)....

  5. Characterizing shallow secondary clarifier performance where conventional flux theory over-estimates allowable solids loading rate. (United States)

    Daigger, Glen T; Siczka, John S; Smith, Thomas F; Frank, David A; McCorquodale, J A

    The performance characteristics of relatively shallow (3.3 and 3.7 m sidewater depth in 30.5 m diameter) activated sludge secondary clarifiers were extensively evaluated during a 2-year testing program at the City of Akron Water Reclamation Facility (WRF), Ohio, USA. Testing included hydraulic and solids loading stress tests, and measurement of sludge characteristics (zone settling velocity (ZSV), dispersed and flocculated total suspended solids), and the results were used to calibrate computational fluid dynamic (CFD) models of the various clarifiers tested. The results demonstrated that good performance could be sustained at surface overflow rates in excess of 3 m/h, as long as the clarifier influent mixed liquor suspended solids (MLSS) concentration was controlled to below critical values. The limiting solids loading rate (SLR) was significantly lower than the value predicted by conventional solids flux analysis based on the measured ZSV/MLSS relationship. CFD analysis suggested that this resulted because mixed liquor entering the clarifier was being directed into the settled sludge blanket, diluting it and also creating a 'thin' concentration sludge blanket that overlays the thicker concentration sludge blanket typically expected. These results indicate the need to determine the allowable SLR for shallow clarifiers using approaches other than traditional solids flux analysis. A combination of actual testing and CFD analyses are demonstrated here to be effective in doing so.

  6. Cr concentration dependence of overestimation of long term creep life in strength enhanced high Cr ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, K., E-mail: [Graduate School of Environmental Studies, Tohoku University, 6-6-02 Aobayama, Sendai 980-8579 (Japan); Ghassemi Armaki, H.; Chen, R.P.; Yoshimi, K. [Graduate School of Environmental Studies, Tohoku University, 6-6-02 Aobayama, Sendai 980-8579 (Japan); Yoshizawa, M.; Igarashi, M. [Corporate Research and Development Laboratories, Sumitomo Metal Industry, Ltd., 1-8 Fuso-Cho, Amagasaki 660-0891 (Japan)


    Creep rupture data and microstructural degradation during aging of high Cr ferritic boiler steels with enhanced creep strength have been studied with special attention to prediction of long term creep rupture life. Tempered lath martensite structure in the high Cr ferritic steels remains unchanged during short term aging, whereas static recovery of the lath martensite structure proceeds when diffusion distance during aging becomes sufficiently long as is the case in long term creep. The static recovery brings about premature failure in long term creep and decreases in apparent activation energy for creep life. The decrease in activation energy is responsible for overestimation of rupture life reported in strength enhanced high Cr ferritic steels. The boundary from a short term region with high activation energy Q{sub H} to a long term region with low activation energy Q{sub L} moves towards longer time with decreasing Cr concentration. The difference in activation energy (Q{sub H} - Q{sub L}) primarily determines the extent of overestimation of rupture life predicted from short term data. In general, the extent of overestimation is less serious at 9%Cr as compared to 12%Cr.

  7. Weighted Feature Significance: A Simple, Interpretable Model of Compound Toxicity Based on the Statistical Enrichment of Structural Features


    Huang, Ruili; Southall, Noel; Xia, Menghang; Cho, Ming-Hsuang; Jadhav, Ajit; Nguyen, Dac-Trung; Inglese, James; Tice, Raymond R.; Austin, Christopher P.


    In support of the U.S. Tox21 program, we have developed a simple and chemically intuitive model we call weighted feature significance (WFS) to predict the toxicological activity of compounds, based on the statistical enrichment of structural features in toxic compounds. We trained and tested the model on the following: (1) data from quantitative high–throughput screening cytotoxicity and caspase activation assays conducted at the National Institutes of Health Chemical Genomics Center, (2) dat...

  8. A more robust model of the biodiesel reaction, allowing identification of process conditions for significantly enhanced rate and water tolerance. (United States)

    Eze, Valentine C; Phan, Anh N; Harvey, Adam P


    A more robust kinetic model of base-catalysed transesterification than the conventional reaction scheme has been developed. All the relevant reactions in the base-catalysed transesterification of rapeseed oil (RSO) to fatty acid methyl ester (FAME) were investigated experimentally, and validated numerically in a model implemented using MATLAB. It was found that including the saponification of RSO and FAME side reactions and hydroxide-methoxide equilibrium data explained various effects that are not captured by simpler conventional models. Both the experiment and modelling showed that the "biodiesel reaction" can reach the desired level of conversion (>95%) in less than 2min. Given the right set of conditions, the transesterification can reach over 95% conversion, before the saponification losses become significant. This means that the reaction must be performed in a reactor exhibiting good mixing and good control of residence time, and the reaction mixture must be quenched rapidly as it leaves the reactor.

  9. Generalized Models: An Application to Identify Environmental Variables That Significantly Affect the Abundance of Three Tree Species

    Directory of Open Access Journals (Sweden)

    Pablo Antúnez


    Full Text Available In defining the environmental preferences of plant species, statistical models are part of the essential tools in the field of modern ecology. However, conventional linear models require compliance with some parametric assumptions and if these requirements are not met, imply a serious limitation of the applied model. In this study, the effectiveness of linear and nonlinear generalized models was examined to identify the unitary effect of the principal environmental variables on the abundance of three tree species growing in the natural temperate forests of Oaxaca, Mexico. The covariates that showed a significant effect on the distribution of tree species were the maximum and minimum temperatures and the precipitation during specific periods. Results suggest that the generalized models, particularly smoothed models, were able to detect the increase or decrease of the abundance against changes in an environmental variable; they also revealed the inflection of the regression. In addition, these models allow partial characterization of the realized niche of a given species according to some specific variables, regardless of the type of relationship.

  10. Use of thermodilution cardiac output overestimates diagnoses of exercise-induced pulmonary hypertension. (United States)

    Hsu, Steven; Brusca, Samuel B; Rhodes, Parker S; Kolb, Todd M; Mathai, Stephen C; Tedford, Ryan J


    Two new definitions of exercise-induced pulmonary hypertension (EIPH) have emerged. Both rely on measuring cardiac output (CO), yet this remains unstandardized. In our cohort of patients undergoing invasive cardiopulmonary exercise testing, we found that using thermodilution CO rather than direct Fick CO led to a significant excess of EIPH diagnoses.

  11. The photon dose calculation algorithm used in breast radiotherapy has significant impact on the parameters of radiobiological models. (United States)

    Petillion, Saskia; Swinnen, Ans; Defraene, Gilles; Verhoeven, Karolien; Weltens, Caroline; Van den Heuvel, Frank


    The comparison of the pencil beam dose calculation algorithm with modified Batho heterogeneity correction (PBC-MB) and the analytical anisotropic algorithm (AAA) and the mutual comparison of advanced dose calculation algorithms used in breast radiotherapy have focused on the differences between the physical dose distributions. Studies on the radiobiological impact of the algorithm (both on the tumor control and the moderate breast fibrosis prediction) are lacking. We, therefore, investigated the radiobiological impact of the dose calculation algorithm in whole breast radiotherapy. The clinical dose distributions of 30 breast cancer patients, calculated with PBC-MB, were recalculated with fixed monitor units using more advanced algorithms: AAA and Acuros XB. For the latter, both dose reporting modes were used (i.e., dose-to-medium and dose-to-water). Next, the tumor control probability (TCP) and the normal tissue complication probability (NTCP) of each dose distribution were calculated with the Poisson model and with the relative seriality model, respectively. The endpoint for the NTCP calculation was moderate breast fibrosis five years post treatment. The differences were checked for significance with the paired t-test. The more advanced algorithms predicted a significantly lower TCP and NTCP of moderate breast fibrosis then found during the corresponding clinical follow-up study based on PBC calculations. The differences varied between 1% and 2.1% for the TCP and between 2.9% and 5.5% for the NTCP of moderate breast fibrosis. The significant differences were eliminated by determination of algorithm-specific model parameters using least square fitting. Application of the new parameters on a second group of 30 breast cancer patients proved their appropriateness. In this study, we assessed the impact of the dose calculation algorithms used in whole breast radiotherapy on the parameters of the radiobiological models. The radiobiological impact was eliminated by

  12. Serum NX-DCP as a New Noninvasive Model to Predict Significant Liver Fibrosis in Chronic Hepatitis C. (United States)

    Saito, Masaya; Yano, Yoshihiko; Hirano, Hirotaka; Momose, Kenji; Yoshida, Masaru; Azuma, Takeshi


    Finding a noninvasive method to predict liver fibrosis using inexpensive and easy-to-use markers is important. We aimed to clarify whether NX-des-γ-carboxyprothrombin (NX-DCP) could become a new noninvasive model to predict liver fibrosis in hepatitis C virus (HCV) related liver disease. We performed a prospective cohort study on a consecutive group of 101 patients who underwent liver biopsy for HCV-related liver disease at Kobe University Hospital. Laboratory measurements were performed on the same day as the biopsy. Factors associated with significant fibrosis (F3-4) were assessed by multivariate analyses. A comparison of predictive ability between multivariate factors and abovementioned noninvasive models was also performed. Increase in serum NX-DCP was significantly related to increase in fibrosis stage (P = 0.006). Moreover, NX-DCP was a multivariate factor associated with the presence of significant fibrosis F 3-4 (median 21 of F0-2 group vs. median 22 of F3-4 group with P = 0.002). The AUC of NX-DCP showed no significant differences compared with those of the AST-to-platelet ratio index (APRI), modified-APRI, the Göteborg University Cirrhosis Index (GUCI), the Lok index, the Hui score, cirrhosis discriminating score (CDS) and the Pohl score (P > 0.05). NX-DCP correlated positively with fibrosis stage and could discriminate well between HCV-related patients with or without significant fibrosis. Moreover, NX-DCP had a similar predictive ability to the abovementioned models, and thereby could be a new noninvasive prediction tool for fibrosis.

  13. Overestimates of survival after HAART: implications for global scale-up efforts.

    Directory of Open Access Journals (Sweden)

    Gregory P Bisson

    Full Text Available BACKGROUND: Monitoring the effectiveness of global antiretroviral therapy scale-up efforts in resource-limited settings is a global health priority, but is complicated by high rates of losses to follow-up after treatment initiation. Determining definitive outcomes of these lost patients, and the effects of losses to follow-up on estimates of survival and risk factors for death after HAART, are key to monitoring the effectiveness of global HAART scale-up efforts. METHODOLOGY/PRINCIPAL FINDINGS: A cohort study comparing clinical outcomes and risk factors for death after HAART initiation as reported before and after tracing of patients lost to follow-up was conducted in Botswana's National Antiretroviral Therapy Program. 410 HIV-infected adults consecutively presenting for HAART were evaluated. The main outcome measures were death or loss to follow-up within the first year after HAART initiation. Of 68 patients initially categorized as lost, over half (58.8% were confirmed dead after tracing. Patient tracing resulted in reporting of significantly lower survival rates when death was used as the outcome and losses to follow-up were censored [1-year Kaplan Meier survival estimate 0.92 (95% confidence interval, 0.88-0.94 before tracing and 0.83 (95% confidence interval, 0.79-0.86 after tracing, log rank P<0.001]. In addition, a significantly increased risk of death after HAART among men [adjusted hazard ratio 1.74 (95% confidence interval, 1.05-2.87] would have been missed had patients not been traced [adjusted hazard ratio 1.41 (95% confidence interval, 0.65-3.05]. CONCLUSIONS/SIGNIFICANCE: Due to high rates of death among patients lost to follow-up after HAART, survival rates may be inaccurate and important risk factors for death may be missed if patients are not actively traced. Patient tracing and uniform reporting of outcomes after HAART are needed to enable accurate monitoring of global HAART scale-up efforts.

  14. A model for microbial phosphorus cycling in bioturbated marine sediments: Significance for phosphorus burial in the early Paleozoic (United States)

    Dale, Andrew W.; Boyle, Richard A.; Lenton, Timothy M.; Ingall, Ellery D.; Wallmann, Klaus


    A diagenetic model is used to simulate the diagenesis and burial of particulate organic carbon (Corg) and phosphorus (P) in marine sediments underlying anoxic versus oxic bottom waters. The latter are physically mixed by animals moving through the surface sediment (bioturbation) and ventilated by burrowing, tube-dwelling organisms (bioirrigation). The model is constrained using an empirical database including burial ratios of Corg with respect to organic P (Corg:Porg) and total reactive P (Corg:Preac), burial efficiencies of Corg and Porg, and inorganic carbon-to-phosphorus regeneration ratios. If Porg is preferentially mineralized relative to Corg during aerobic respiration, as many previous studies suggest, then the simulated Porg pool is found to be completely depleted. A modified model that incorporates the redox-dependent microbial synthesis of polyphosphates and Porg (termed the microbial P pump) allows preferential mineralization of the bulk Porg pool relative to Corg during both aerobic and anaerobic respiration and is consistent with the database. Results with this model show that P burial is strongly enhanced in sediments hosting fauna. Animals mix highly labile Porg away from the aerobic sediment layers where mineralization rates are highest, thereby mitigating diffusive PO43- fluxes to the bottom water. They also expand the redox niche where microbial P uptake occurs. The model was applied to a hypothetical shelf setting in the early Paleozoic; a time of the first radiation of benthic fauna. Results show that even shallow bioturbation at that time may have had a significant impact on P burial. Our model provides support for a recent study that proposed that faunal radiation in ocean sediments led to enhanced P burial and, possibly, a stabilization of atmospheric O2 levels. The results also help to explain Corg:Porg ratios in the geological record and the persistence of Porg in ancient marine sediments.

  15. An automated nowcasting model of significant instability events in the flight terminal area of Rio de Janeiro, Brazil (United States)

    Borges França, Gutemberg; Valdonel de Almeida, Manoel; Rosette, Alessana C.


    This paper presents a novel model, based on neural network techniques, to produce short-term and local-specific forecasts of significant instability for flights in the terminal area of Galeão Airport, Rio de Janeiro, Brazil. Twelve years of data were used for neural network training/validation and test. Data are originally from four sources: (1) hourly meteorological observations from surface meteorological stations at five airports distributed around the study area; (2) atmospheric profiles collected twice a day at the meteorological station at Galeão Airport; (3) rain rate data collected from a network of 29 rain gauges in the study area; and (4) lightning data regularly collected by national detection networks. An investigation was undertaken regarding the capability of a neural network to produce early warning signs - or as a nowcasting tool - for significant instability events in the study area. The automated nowcasting model was tested using results from five categorical statistics, indicated in parentheses in forecasts of the first, second, and third hours, respectively, namely proportion correct (0.99, 0.97, and 0.94), BIAS (1.10, 1.42, and 2.31), the probability of detection (0.79, 0.78, and 0.67), false-alarm ratio (0.28, 0.45, and 0.73), and threat score (0.61, 0.47, and 0.25). Possible sources of error related to the test procedure are presented and discussed. The test showed that the proposed model (or neural network) can grab the physical content inside the data set, and its performance is quite encouraging for the first and second hours to nowcast significant instability events in the study area.

  16. SCORTEN overestimates mortality in the setting of a standardized treatment protocol. (United States)

    Imahara, Scott D; Holmes, James H; Heimbach, David M; Engrav, Loren E; Honari, Shari; Klein, Matthew B; Gibran, Nicole S


    Toxic epidermal necrolysis (TEN) is a rare, severe, exfoliative disorder with a high mortality rate. SCORTEN is a recently developed scoring system that estimates severity and predicts mortality in patients with TEN based on seven independent clinical risk factors recorded within the first 24 hours of admission. An increasing SCORTEN level predicts a higher mortality rate. For more than 20 years, the treatment of TEN at our institution has involved the use of a standardized clinical pathway that includes removal of sloughed epidermis, dermal protection with porcine xenograft, early enteral nutrition, and critical care monitoring. We hypothesize that this standardized clinical approach will result in a lower mortality rate than predicted by SCORTEN. A retrospective review was performed on all patients treated for TEN using the standardized pathway from February 1987 to March 2004. SCORTEN was calculated in each patient. One hundred nine patients were treated for TEN during the study period. Overall observed mortality was 20% compared with a SCORTEN predicted mortality of 30%, resulting in a relative reduction in mortality of 33% (P = .011). In addition, observed probability of death was lower than predicted at all levels, except at SCORTEN score of 6 or greater. In conclusion, TEN remains a life-threatening disease with a high mortality rate. Our standardized treatment protocol results in significantly improved outcomes compared to those predicted by SCORTEN.

  17. The definition of HIV-associated neurocognitive disorders: are we overestimating the real prevalence?

    Directory of Open Access Journals (Sweden)

    Gisslén Magnus


    Full Text Available Abstract Background A substantial prevalence of mild neurocognitive disorders has been reported in HIV, also in patients treated with combination antiretroviral therapy (cART. This includes a new disorder that has been termed asymptomatic neurocognitive impairment (ANI. Discussion ANI is identified by performance on formal neuropsychological testing that is at least 1 SD below the mean of normative scores in at least two cognitive domains out of at least five examined in patients without associated symptoms or evident functional impairment in daily living. While two tests are recommended to assess each domain, only one is required to fulfill this diagnostic criterion. Unfortunately, this definition necessitates that about 20% of the cognitively normal HIV-infected population is classified as suffering ANI. This liberal definition raises important ethical concerns and has as well diagnostic and therapeutic implications. Since neither its biological substrate, prognostic significance nor therapeutic implications are clearly established, we recommend that this diagnosis be modified or applied cautiously. Summary The diagnoses of less severe forms of neurocognitive disorders in HIV relies on the outcomes of neuropsychological testing, and a high proportion of HIV-infected patients with effective cART may be classified as neurocognitively abnormal using the current criteria. The definition of ANI is not stringent, and results in approximately 20% of the population being classified as abnormal. To us this seems an unacceptable false-positive rate.

  18. The definition of HIV-associated neurocognitive disorders: are we overestimating the real prevalence? (United States)

    Gisslén, Magnus; Price, Richard W; Nilsson, Staffan


    A substantial prevalence of mild neurocognitive disorders has been reported in HIV, also in patients treated with combination antiretroviral therapy (cART). This includes a new disorder that has been termed asymptomatic neurocognitive impairment (ANI). ANI is identified by performance on formal neuropsychological testing that is at least 1 SD below the mean of normative scores in at least two cognitive domains out of at least five examined in patients without associated symptoms or evident functional impairment in daily living. While two tests are recommended to assess each domain, only one is required to fulfill this diagnostic criterion. Unfortunately, this definition necessitates that about 20% of the cognitively normal HIV-infected population is classified as suffering ANI. This liberal definition raises important ethical concerns and has as well diagnostic and therapeutic implications. Since neither its biological substrate, prognostic significance nor therapeutic implications are clearly established, we recommend that this diagnosis be modified or applied cautiously. The diagnoses of less severe forms of neurocognitive disorders in HIV relies on the outcomes of neuropsychological testing, and a high proportion of HIV-infected patients with effective cART may be classified as neurocognitively abnormal using the current criteria. The definition of ANI is not stringent, and results in approximately 20% of the population being classified as abnormal. To us this seems an unacceptable false-positive rate.

  19. Pomalidomide shows significant therapeutic activity against CNS lymphoma with a major impact on the tumor microenvironment in murine models. (United States)

    Li, Zhimin; Qiu, Yushi; Personett, David; Huang, Peng; Edenfield, Brandy; Katz, Jason; Babusis, Darius; Tang, Yang; Shirely, Michael A; Moghaddam, Mehran F; Copland, John A; Tun, Han W


    Primary CNS lymphoma carries a poor prognosis. Novel therapeutic agents are urgently needed. Pomalidomide (POM) is a novel immunomodulatory drug with anti-lymphoma activity. CNS pharmacokinetic analysis was performed in rats to assess the CNS penetration of POM. Preclinical evaluation of POM was performed in two murine models to assess its therapeutic activity against CNS lymphoma. The impact of POM on the CNS lymphoma immune microenvironment was evaluated by immunohistochemistry and immunofluorescence. In vitro cell culture experiments were carried out to further investigate the impact of POM on the biology of macrophages. POM crosses the blood brain barrier with CNS penetration of ~ 39%. Preclinical evaluations showed that it had significant therapeutic activity against CNS lymphoma with significant reduction in tumor growth rate and prolongation of survival, that it had a major impact on the tumor microenvironment with an increase in macrophages and natural killer cells, and that it decreased M2-polarized tumor-associated macrophages and increased M1-polarized macrophages when macrophages were evaluated based on polarization status. In vitro studies using various macrophage models showed that POM converted the polarization status of IL4-stimulated macrophages from M2 to M1, that M2 to M1 conversion by POM in the polarization status of lymphoma-associated macrophages is dependent on the presence of NK cells, that POM induced M2 to M1 conversion in the polarization of macrophages by inactivating STAT6 signaling and activating STAT1 signaling, and that POM functionally increased the phagocytic activity of macrophages. Based on our findings, POM is a promising therapeutic agent for CNS lymphoma with excellent CNS penetration, significant preclinical therapeutic activity, and a major impact on the tumor microenvironment. It can induce significant biological changes in tumor-associated macrophages, which likely play a major role in its therapeutic activity against CNS

  20. Are ammonia emissions from field-applied slurry substantially over-estimated in European emission inventories?

    Directory of Open Access Journals (Sweden)

    J. Sintermann


    Full Text Available The EMEP/EEA guidebook 2009 for agricultural emission inventories reports an average ammonia (NH3 emission factor (EF by volatilisation of 55% of the applied total ammoniacal nitrogen (TAN content for cattle slurry, and 35% losses for pig slurry, irrespective of the type of surface or slurry characteristics such as dry matter content and pH. In this review article, we compiled over 350 measurements of EFs published between 1991 and 2011. The standard slurry application technique during the early years of this period, when a large number of measurements were made, was spreading by splash plate, and as a result reference EFs given in many European inventories are predominantly based on this technique. However, slurry application practices have evolved since then, while there has also been a shift in measurement techniques and investigated plot sizes. We therefore classified the available measurements according to the flux measurement technique or measurement plot size and year of measurement. Medium size plots (usually circles between 20 to 50 m radius generally yielded the highest EFs. The most commonly used measurement setups at this scale were based on the Integrated Horizontal Flux method (IHF or the ZINST method (a simplified IHF method. Several empirical models were published in the years 1993 to 2003 predicting NH3 EFs as a function of meteorology and slurry characteristics (Menzi et al., 1998; Søgaard et al., 2002. More recent measurements show substantially lower EFs which calls for new measurement series in order to validate the various measurement approaches against each other and to derive revised inputs for inclusion into emission inventories.

  1. Students with Non-Proficient Information Seeking Skills Greatly Over-Estimate Their Abilities. A Review of: Gross, Melissa, and Don Latham.

    Directory of Open Access Journals (Sweden)

    David Herron


    the actual percentage correct was 65%. The estimated score was 50 and the actual 39, and the estimated comparison with their peers was 77% and the actual 53%. All three measures demonstrated a significant difference between estimated and actual values. On the ILT, the mean score for the bottom tier of the students was 34, and the mean score for the top tier was 42, showing a significant difference between the top and bottom tier in a t-test. On the ILT, 23 students scored less than 39 (= nonproficient, 27 scored between 39-53 (proficient. Only one student, a top quartile participant, showed advanced information literacy skills (a score above 53. In the post-survey, the students still over-estimated their performance, but to a lesser degree. All three groups adjusted their self-estimates in the post-survey in response to information skills testing, but the non-proficient group over-estimated their skills to a higher degree, on both pre-and post-surveys. The estimated percentage correct answers for the whole group was69%, but the actual was 65%, the estimated score was 44 and the actual 39, and the estimated comparison with their peers was 70% and the actual 53%. All three measures demonstrated a significant difference. All results show that the original hypothesis holds: non-proficient students over-estimate their abilities to a greater degree, both in terms of score and performance relative totheir peers. The LAS was used to see if there was a relationship between student scores on the ILT and library anxiety. Bi-variate analysis was performed on the ILT scores and student total scores on the LAS, and the results show that library anxiety tended to decrease with higher scores on the ILT. This result was not expected from the theory. In the pre-survey, the students were asked how they had obtained their information literacy skills. The top tier indicated a reliance on more formal sources (e.g. school library media center, classroom, and/or public library, while the

  2. Hydrothermal Fe cycling and deep ocean organic carbon scavenging: Model-based evidence for significant POC supply to seafloor sediments (United States)

    German, C. R.; Legendre, L. L.; Sander, S. G.; Niquil, N.; Luther, G. W.; Bharati, L.; Han, X.; Le Bris, N.


    Submarine hydrothermal venting has recently been identified to have the potential to impact ocean biogeochemistry at the global scale. This is the case because processes active in hydrothermal plumes are so vigorous that the residence time of the ocean, with respect to cycling through hydrothermal plumes, is comparable to that of deep ocean mixing caused by thermohaline circulation. Recently, it has been argued that seafloor venting may provide a significant source of bio-essential Fe to the oceans as the result of a close coupling between Fe and organic carbon in hydrothermal plumes. But a complementary question remains to be addressed: does this same intimate Fe-Corg association in hydrothermal plumes cause any related impact to the global C cycle? To address this, SCOR-InterRidge Working Group 135 developed a modeling approach to synthesize site-specific field data from the East Pacific Rise 9°50‧ N hydrothermal field, where the range of requisite data sets is most complete, and combine those inputs with global estimates for dissolved Fe inputs from venting to the oceans to establish a coherent model with which to investigate hydrothermal Corg cycling. The results place new constraints on submarine Fe vent fluxes worldwide, including an indication that the majority of Fe supplied to hydrothermal plumes should come from entrainment of diffuse flow. While this same entrainment is not predicted to enhance the supply of dissolved organic carbon to hydrothermal plumes by more than ∼10% over background values, what the model does indicate is that scavenging of carbon in association with Fe-rich hydrothermal plume particles should play a significant role in the delivery of particulate organic carbon to deep ocean sediments, worldwide.

  3. Changes of High Mobility Group box 1 in Serum of Pig Acute Hepatic Failure Model and Significance

    Institute of Scientific and Technical Information of China (English)

    Fan ZHANG; Yongwen HE; Zhongping DUAN


    The role of the high mobility group box 1 (HMGB-1) in acute hepatic failure and the ef- fect of artificial liver support system treatment on HMGB-1 level were investigated. Pig models of acute hepatic failure were induced by D-galactosamine and randomly divided into two groups with or without artificial liver support system treatment. Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels were detected by the enzyme linked immunosorbent assay (ELISA), the expression of HMGB-1 by Western blot, and serum levels of HMGB-1, liver function and hepatic pathology were observed after artificial liver support system treatment. The levels of TNF-α and IL-1β were increased and reached the peak at 24th h in the acute hepatic failure group, then quickly decreased. The serum level of HMGB-1 was increased at 24th h in the acute hepatic failure group and reached the peak at 48th h, then kept a stable high level. Significant liver injury appeared at 24th h and was continuously getting worse in the pig models of acute hepatic failure. In contrast, the liver injury was significantly alleviated and serum level of HMGB-1 was significantly decreased in the group treated with artificial liver support system (P<0.05). It was suggested that HMGB-1 may participate in the inflammatory response and liver injury in the late stage of the acute liver failure. Artificial liver support system treatment can reduce serum HMGB-1 level and relieve liver pathological damage.

  4. Overestimation of mentally retarded persons' IQs using the PPVT: a re-analysis and some implications for future research. (United States)

    Facon, B; Bollengier, T; Grubar, J C


    Numerous validity studies have shown that the PPVT consistently overestimates mentally retarded persons' IQs. One possible interpretation is that this phenomenon is an outcome of the dissociation between their cognitive level and their experience. Indeed, compared to intellectually average subjects of the same mental age, they have had more learning opportunities, simply because they have lived longer. In order to validate this hypothesis, the French version of the PPVT, Raven's Coloured Progressive Matrices (RCPM), and the 1966 version of the Binet-Simon were administered to 90 subjects of various chronological ages matched on mental age (30 nonretarded 5 year olds and two groups of 30 retarded subjects aged 10 and 16 years, respectively). The results indicate that CA exerts a strong effect on vocabulary, but not on RCPM performance. The research implications of this finding are discussed.

  5. Modeling plant, microorganisms, and mineral surface competition for soil nitrogen and phosphorus: Competition representations and ecological significance (United States)

    Zhu, Q.; Riley, W. J.; Chambers, J. Q.; Tang, J.


    It is widely accepted that terrestrial ecosystem carbon dynamics are strongly coupled and controlled by soil nutrients status. Nutrient availability serves as an indicator of aboveground carbon productivity and ecosystem stability, especially when soils are infertile. In these conditions, plants have to outcompete microorganism and mineral surfaces to acquire nutrients required for photosynthesis, respiration, seed production, defense, etc. It is usually hypothesized that microbes are short-term winners but long-term losers in nutrient competition. Microbes quickly trap available soil nitrogen and phosphorous, thereby preventing nutrient inaccessibility through hydrological leaching and mineral surface adsorption. Over longer temporal scales, nutrients are released into the soil and become available for plant uptake. Despite its ecological significance, nutrient competition is either absent or over-simplified (e.g., assuming all consumers are equally competitive) in terrestrial biogeochemistry models. Here, we aim to test the representation of different competitive strategies and to investigate their ecological consequences with a newly developed biogeochemical model structure. The new model includes three major soil nutrients (ammonia, nitrate, and phosphate) and multiple consumers (plants, microbes, mineral surfaces, nitrifiers, and denitrifiers). We analyze predicted soil carbon, nitrogen, and phosphorus dynamics with three different competitive strategies: (1) plants compete poorly against microorganisms; (2) all consumers are equally competitive; and (3) an explicit Equilibrium Chemical Approximation (ECA; Tang and Riley (2013)) treatment. We find that very different ecosystem states are predicted when assuming different competitive structures, and that the ECA approach provides the best match with a large suite of observational constraints from tropical experimental and transect studies. We conclude that terrestrial biogeochemical models should represent a

  6. Modeling the significance of including C redistribution when determining changes in net carbon storage along a cultivated toposequence (United States)

    Chirinda, Ngonidzashe; Olesen, Jørgen E.; Heckrath, Goswin; Paradelo Pérez, Marcos; Taghizadeh-Toosi, Arezoo


    Globally, soil carbon (C) reserves are second only to those in the ocean, and accounts for a significant C reservoir. In the case of arable soils, the quantity of stored C is influenced by various factors (e.g. management practices). Currently, the topography related influences on in-field soil C dynamics remain largely unknown. However, topography is known to influence a multiplicity of factors that regulate C input, storage and redistribution. To understand the patterns and untangle the complexity of soil C dynamics in arable landscapes, our study was conducted with soils from shoulderslope and footslope positions on a 7.1 ha winter wheat field in western Denmark. We first collected soil samples from shoulderslope and footslope positions with various depth intervals down to 100 cm and analyzed them for physical and chemical properties including texture and soil organic C contents. In-situ carbon dioxide (CO2) concentrations were measured at different soil profile depths at both positions for a year. Soil moisture content and temperature at 5 and 40 cm depth was measured continuously. Additionally, surface soil CO2 fluxes at shoulderslope and footslope positions were measured. We then used measurement data collected from the two landscape positions to calibrate the one-dimensional mechanistic model SOILCO2 module of the HYDRUS-1D software package and obtained soil CO2 fluxes from soil profile at two landscape positions. Furthermore, we tested whether the inclusion of vertical and lateral soil C movement improved the modeling of C dynamics in cultivated landscapes. For that, soil profile CO2 fluxes were compared with those obtained using a simple process-based soil whole profile C model, C-TOOL, which was modified to include vertical and lateral movement of C on landscape. Our results highlight the need to consider vertical and lateral soil C movement in the modeling of C dynamics in cultivated landscapes, for better qualification of net carbon storage.

  7. [Can overestimating one's own capacities of action lead to fall? A study on the perception of affordance in the elderly]. (United States)

    Luyat, Marion; Domino, Delphine; Noël, Myriam


    Falls are frequent in the elderly and account for medical complications and loss of autonomy. Affordance, a concept proposed by Gibson, can help to understand a possible cause of falls. An affordance is defined as a potentiality of action offered by the environment in relation with both the properties of this environment and the properties of the organism. Most of our daily activities reflect a perfect adjustment between the perception of these potentialities of action and our actual action abilities. In other words, we correctly perceive affordances. However, in the elderly, postural abilities are reduced and equilibration is more unstable. Thus, some falls could result from a misperception of the affordances of posturability. The aim of our study was to test the hypothesis that cognitive overestimation of real postural abilities in the elderly may cause falls. There would be a gap between what the old subjects believe to be able to do and what they actually can do. Fifteen young adults (mean age = 24 years) and fifteen older adults (mean age = 72 years) had to judge if they were able to stand upright on an inclined surface. The exploration of the inclined surface was made in two conditions: visually and also by haptics (without vision with a cane). In a second part, we measured their real postural stance on the inclined surface. The results show that the perceptual judgments were not different among old and young people. However, as expected, the old subjects had lower postural boundaries than the younger. They could stand on lower inclinations of the surface. These results show an involution of the perception of the affordances in aging. They support the hypothesis of a cognitive overestimation of action abilities in the elderly, possibly due to a difficulty to actualize the new limits for action.

  8. Severe hypoglycemia in peritoneal dialysis patients due to overestimation of blood glucose by the point-of-care glucometer

    Directory of Open Access Journals (Sweden)

    Hasan M Al-Dorzi


    Full Text Available Although overestimation of blood glucose (BG by certain glucometers in peritoneal dialysis (PD patients has been reported, awareness of this problem by healthcare providers of multiple disciplines and different specialties is probably insufficient. This is a case series of four patients who had severe symptomatic hypoglycemia and normal BG by point-of-care glucometer at a tertiary care center from December 2007 to September 2008. We report four insulin-treated diabetic patients (age = 58.2 ± 16.2 years, 3 men and 1 woman on PD, who had acute decrease in level of consciousness in the emergency department (n = 1 and the hospital ward (n = 3. While they had their symptoms, they all had normal BG measured by the Accuchek glucometer (7.1 ± 3.3 mmol/L; nonetheless, simultaneous or near-simultaneous laboratory-measured BG levels were very low (2.0 ± 1.3 mmol/L. The mean difference in BG was 5.8 mmol/L (12 simultaneous or near-simultaneous measurements. Three patients had icodextrin-based PD in the night before symptomatic hypoglycemia. The first two patients, whose treatment for hypoglycemia was delayed, remained comatose and died later. The latter two patients were promptly treated with intravenous dextrose and did not have any neurologic sequelae. One of them died later from multiple organ failure. Over-estimation of BG in peritoneal dialysis patients by certain point-of-care glucometers is a serious problem and can be fatal. Increased awareness of this problem for all healthcare providers and use of appropriate glucometers are required.

  9. Sulfidation as a natural antidote to metallic nanoparticles is overestimated: CuO sulfidation yields CuS nanoparticles with increased toxicity in medaka (Oryzias latipes) embryos. (United States)

    Li, Lingxiangyu; Hu, Ligang; Zhou, Qunfang; Huang, Chunhua; Wang, Yawei; Sun, Cheng; Jiang, Guibin


    Sulfidation is considered as a natural antidote to toxicity of metallic nanoparticles (NPs). The detoxification contribution from sulfidation, however, may vary depending on sulfidation mechanisms. Here we present the dissolution-precipitation instead of direct solid-state-shell mechanism to illustrate the process of CuO-NPs conversion to CuS-NPs in aqueous solutions. Accordingly, the CuS-NPs at environmentally relevant concentrations showed much stronger interference on Japanese medaka (Oryzias latipes) embryo hatching than CuO-NPs, which was probably due to elevated free copper ions released from CuS-NPs, leading to significant increase in oxidative stress and causing toxicity in embryos. The larval length was significantly reduced by CuS-NPs, however, no other obviously abnormal morphological features were identified in the hatched larvae. Co-introduction of a metal ion chelator [ethylene diamine tetraacetic acid (EDTA)] could abolish the hatching inhibition induced by CuS-NPs, indicating free copper ions released from CuS-NPs play an important role in hatching interference. This work documents for the first time that sulfidation as a natural antidote to metallic NPs is being overestimated, which has far reaching implications for risk assessment of metallic NPs in aquatic environment.

  10. Optical polarization tractography revealed significant fiber disarray in skeletal muscles of a mouse model for Duchenne muscular dystrophy. (United States)

    Wang, Y; Zhang, K; Wasala, N B; Duan, D; Yao, G


    Optical polarization tractography (OPT) was recently developed to visualize tissue fiber architecture with cellular-level resolution and accuracy. In this study, we explored the feasibility of using OPT to study muscle disease in the mdx4cv mouse model of Duchenne muscular dystrophy. The freshly dissected tibialis anterior muscles of mdx4cv and normal mice were imaged. A "fiber disarray index" (FDI) was developed to quantify the myofiber disorganization. In necrotic muscle regions of the mdx4cv mice, the FDI was significantly elevated and can be used to segment the 3D necrotic regions for assessing the overall muscle damage. These results demonstrated the OPT's capability for imaging microscopic fiber alternations in muscle research.

  11. Significance of stromal-1 and stromal-2 signatures and biologic prognostic model in diffuse large B-cell lymphoma (United States)

    Abdou, Asmaa Gaber; Asaad, Nancy; Kandil, Mona; Shabaan, Mohammed; Shams, Asmaa


    Objective : Diffuse Large B Cell Lymphoma (DLBCL) is a heterogeneous group of tumors with different biological and clinical characteristics that have diverse clinical outcomes and response to therapy. Stromal-1 signature of tumor microenvironment of DLBCL represents extracellular matrix deposition and histiocytic infiltrate, whereas stromal-2 represents angiogenesis that could affect tumor progression. Methods : The aim of the present study is to assess the significance of stromal-1 signature using SPARC-1 and stromal-2 signature using CD31 expression and then finally to construct biologic prognostic model (BPM) in 60 cases of DLBCL via immunohistochemistry. Results : Microvessel density (PBPM showed that 42 cases (70%) were of low biologic score (0–1) and 18 cases (30%) were of high biologic score (2–3). Low BPM cases showed less probability for splenic involvement (P=0.04) and a higher rate of complete response to therapy compared with high score cases (P=0.08). Conclusions : The DLBCL microenvironment could modulate tumor progression behavior since angiogenesis and SPARC positive stromal cells promote dissemination by association with spleen involvement and capsular invasion. Biologic prognostic models, including modified BPM, which considered cell origin of DLBCL and stromal signature pathways, could determine DLBCL progression and response to therapy. PMID:28607806

  12. Attenuation of Rhes activity significantly delays the appearance of behavioral symptoms in a mouse model of Huntington's disease.

    Directory of Open Access Journals (Sweden)

    Brandon A Baiamonte

    Full Text Available Huntington's disease (HD is a neuropsychiatric disorder characterized by choreiform movement of the limbs, cognitive disability, psychosis and dementia. It is invariably associated with an abnormally long CAG expansion within the IT15 gene on human chromosome 4. Although the mutant huntingtin protein is ubiquitously expressed in HD patients, cellular degeneration occurs predominantly in neurons within the corpus striatum and cerebral cortex. The Ras homolog Rhes is expressed very selectively in the precise brain areas affected by HD. Recent in vitro work suggests that Rhes may be a co-factor with mutant huntingtin in cell death. The objective of the present study was to examine whether the inhibition of Rhes would attenuate or delay the symptoms of HD in vivo. We used a transgenic mouse model of HD crossed with Rhes knockout mice to show that the behavioral symptoms of HD are regulated by Rhes. HD(+/Rhes(-/- mice showed significantly delayed expression of HD-like symptoms in this in vivo model. Drugs that block or inhibit the actions of Rhes may be useful as the first treatments for HD.

  13. Filtrate of Phellinus linteus Broth Culture Reduces Infarct Size Significantly in a Rat Model of Permanent Focal Cerebral Ischemia. (United States)

    Suzuki, Sakiko; Kawamata, Takakazu; Okada, Yoshikazu; Kobayashi, Tomonori; Nakamura, Tomoyuki; Hori, Tomokatsu


    Phellinus linteus, a natural growing mushroom, has been known to exhibit anti-tumor, anti-inflammatory, anti-allergic and anti-oxidant effects. Aiming to exploit the neuroprotective effects of P. linteus, we evaluated its effects on infarct volume reduction in a rat model of focal cerebral ischemia. Male Sprague-Dawley rats were subjected to right middle cerebral artery occlusion. Filtrate of P. linteus broth culture (various doses), fractionated filtrate (based on molecular weight) or control medium was administered intraperitoneally to rats before or after ischemia induction. Rats were killed at 24 h after the stroke surgery. Cortical and caudoputaminal infarct volumes were determined separately using an image analysis program following staining with 2,3,5-triphenyltetrazolium chloride. Significant cortical infarct volume reductions were found in the pre-treatment groups (30 and 60 minutes before onset of cerebral ischemia) compared with the control group, showing dose dependence. Posttreatment (30 minutes after ischemic onset) also significantly reduced cortical infarct volume. Furthermore, the higher molecular weight (≥12 000) fraction of the culture filtrate was more effective compared with the lower molecular weight fraction. The present findings suggest that P. linteus may be a new promising approach for the treatment of focal cerebral ischemia, with the additional benefit of a wide therapeutic time window since significant infarct volume reduction is obtained by administration even after the ischemic event. Our finding that the higher molecular weight fraction of the P. linteus culture filtrate demonstrated more prominent effect may provide a clue to identify the neuroprotective substances and mechanisms.

  14. Filtrate of Phellinus linteus Broth Culture Reduces Infarct Size Significantly in a Rat Model of Permanent Focal Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Sakiko Suzuki


    Full Text Available Phellinus linteus, a natural growing mushroom, has been known to exhibit anti-tumor, anti-inflammatory, anti-allergic and anti-oxidant effects. Aiming to exploit the neuroprotective effects of P. linteus, we evaluated its effects on infarct volume reduction in a rat model of focal cerebral ischemia. Male Sprague-Dawley rats were subjected to right middle cerebral artery occlusion. Filtrate of P. linteus broth culture (various doses, fractionated filtrate (based on molecular weight or control medium was administered intraperitoneally to rats before or after ischemia induction. Rats were killed at 24 h after the stroke surgery. Cortical and caudoputaminal infarct volumes were determined separately using an image analysis program following staining with 2,3,5-triphenyltetrazolium chloride. Significant cortical infarct volume reductions were found in the pre-treatment groups (30 and 60 minutes before onset of cerebral ischemia compared with the control group, showing dose dependence. Posttreatment (30 minutes after ischemic onset also significantly reduced cortical infarct volume. Furthermore, the higher molecular weight (≥12 000 fraction of the culture filtrate was more effective compared with the lower molecular weight fraction. The present findings suggest that P. linteus may be a new promising approach for the treatment of focal cerebral ischemia, with the additional benefit of a wide therapeutic time window since significant infarct volume reduction is obtained by administration even after the ischemic event. Our finding that the higher molecular weight fraction of the P. linteus culture filtrate demonstrated more prominent effect may provide a clue to identify the neuroprotective substances and mechanisms.

  15. GeoSciML v3.0 - a significant upgrade of the CGI-IUGS geoscience data model (United States)

    Raymond, O.; Duclaux, G.; Boisvert, E.; Cipolloni, C.; Cox, S.; Laxton, J.; Letourneau, F.; Richard, S.; Ritchie, A.; Sen, M.; Serrano, J.-J.; Simons, B.; Vuollo, J.


    GeoSciML version 3.0 (, released in late 2011, is the latest version of the CGI-IUGS* Interoperability Working Group geoscience data interchange standard. The new version is a significant upgrade and refactoring of GeoSciML v2 which was released in 2008. GeoSciML v3 has already been adopted by several major international interoperability initiatives, including OneGeology, the EU INSPIRE program, and the US Geoscience Information Network, as their standard data exchange format for geoscience data. GeoSciML v3 makes use of recently upgraded versions of several Open Geospatial Consortium (OGC) and ISO data transfer standards, including GML v3.2, SWE Common v2.0, and Observations and Measurements v2 (ISO 19156). The GeoSciML v3 data model has been refactored from a single large application schema with many packages, into a number of smaller, but related, application schema modules with individual namespaces. This refactoring allows the use and future development of modules of GeoSciML (eg; GeologicUnit, GeologicStructure, GeologicAge, Borehole) in smaller, more manageable units. As a result of this refactoring and the integration with new OGC and ISO standards, GeoSciML v3 is not backwardly compatible with previous GeoSciML versions. The scope of GeoSciML has been extended in version 3.0 to include new models for geomorphological data (a Geomorphology application schema), and for geological specimens, geochronological interpretations, and metadata for geochemical and geochronological analyses (a LaboratoryAnalysis-Specimen application schema). In addition, there is better support for borehole data, and the PhysicalProperties model now supports a wider range of petrophysical measurements. The previously used CGI_Value data type has been superseded in favour of externally governed data types provided by OGC's SWE Common v2 and GML v3.2 data standards. The GeoSciML v3 release includes worked examples of best practice in delivering geochemical

  16. Human leukocyte antigen class II transgenic mouse model unmasks the significant extrahepatic pathology in toxic shock syndrome. (United States)

    Tilahun, Ashenafi Y; Marietta, Eric V; Wu, Tsung-Teh; Patel, Robin; David, Chella S; Rajagopalan, Govindarajan


    Among the exotoxins produced by Staphylococcus aureus and Streptococcus pyogenes, the superantigens (SAgs) are the most potent T-cell activators known to date. SAgs are implicated in several serious diseases including toxic shock syndrome (TSS), Kawasaki disease, and sepsis. However, the immunopathogenesis of TSS and other diseases involving SAgs are still not completely understood. The commonly used conventional laboratory mouse strains do not respond robustly to SAgs in vivo. Therefore, they must be artificially rendered susceptible to TSS by using sensitizing agents such as d-galactosamine (d-galN), which skews the disease exclusively to the liver and, hence, is not representative of the disease in humans. SAg-induced TSS was characterized using transgenic mice expressing HLA class II molecules that are extremely susceptible to TSS without d-galN. HLA-DR3 transgenic mice recapitulated TSS in humans with extensive multiple-organ inflammation affecting the lung, liver, kidneys, heart, and small intestines. Heavy infiltration with T lymphocytes (both CD4(+) and CD8+), neutrophils, and macrophages was noted. In particular, the pathologic changes in the small intestines were extensive and accompanied by significantly altered absorptive functions of the enterocytes. In contrast to massive liver failure alone in the d-galN sensitization model of TSS, findings of the present study suggest that gut dysfunction might be a key pathogenic event that leads to high morbidity and mortality in humans with TSS.

  17. Organization as Information Processing Systems. Toward a Model of the Research Factors Associated with Significant Research Outcomes. (United States)


    and %- , during research projects that were related to research outcomes. The Ambidextrous model, which includes both organic and mechanistic make choices with greater li4kelihood for innovative outcomes. p A potential side benefit from better knowledge of the research process * maY...aspect of the research process. The models are referred to respectively as the Davis model, the Antecedents model, and the Ambidextrous model. These

  18. A non-traditional model of the metabolic syndrome: the adaptive significance of insulin resistance in fasting-adapted seals

    Directory of Open Access Journals (Sweden)

    Dorian S Houser


    Full Text Available Insulin resistance in modern society is perceived as a pathological consequence of excess energy consumption and reduced physical activity. Its presence in relation to the development of cardiovascular risk factors has been termed the metabolic syndrome, which produces increased mortality and morbidity and which is rapidly increasing in human populations. Ironically, insulin resistance likely evolved to assist animals during food shortages by increasing the availability of endogenous lipid for catabolism while protecting protein from use in gluconeogenesis and eventual oxidation. Some species that incorporate fasting as a predictable component of their life history demonstrate physiological traits similar to the metabolic syndrome during prolonged fasts. One such species is the northern elephant seal (Mirounga angustirostris, which fasts from food and water for periods of up to three months. During this time, ~90% of the seals metabolic demands are met through fat oxidation and circulating non-esterified fatty acids are high (0.7-3.2 mM. All life history stages of elephant seal studied to date demonstrate insulin resistance and fasting hyperglycemia as well as variations in hormones and adipocytokines that reflect the metabolic syndrome to some degree. Elephant seals demonstrate some intriguing adaptations with the potential for medical advancement; for example, ketosis is negligible despite significant and prolonged fatty acid oxidation and investigation of this feature might provide insight into the treatment of diabetic ketoacidosis. The parallels to the metabolic syndrome are likely reflected to varying degrees in other marine mammals, most of which evolved on diets high in lipid and protein content but essentially devoid of carbohydrate. Utilization of these natural models of insulin resistance may further our understanding of the pathophysiology of the metabolic syndrome in humans and better assist the development of preventative measures

  19. On the significance of the noise model for the performance of a linear MPC in closed-loop operation

    DEFF Research Database (Denmark)

    Hagdrup, Morten; Boiroux, Dimitri; Mahmoudi, Zeinab


    models typically means less parameters to identify. Systematic tuning of such controllers is discussed. Simulation studies are conducted for linear time-invariant systems showing that choosing a noise model of low order is beneficial for closed-loop performance. (C) 2016, IFAC (International Federation...... of Automatic Control) Hosting by Elsevier Ltd. All rights reserved....

  20. Antibody screening tests variably overestimate the prevalence of hepatitis C virus infection among HIV-infected adults in Ghana. (United States)

    King, S; Adjei-Asante, K; Appiah, L; Adinku, D; Beloukas, A; Atkins, M; Sarfo, S F; Chadwick, D; Phillips, R O; Geretti, A M


    HIV coinfection with HCV has been poorly studied in sub-Saharan Africa, and the reliability of available seroprevalence estimates remains uncertain. The study aim was to determine HCV RNA prevalence in HIV-infected subjects receiving care in Kumasi, Ghana, and relate the findings to HCV antibody detection. From a population of 1520 HIV-infected adults, all HBsAg-positive subjects (n = 236) and a random subset of HBsAg-negative subject (n = 172) were screened for HCV RNA using pooled plasma; positive samples were genotyped by core and NS5B sequencing. HCV antibodies were detected by three commercial screening assays and confirmed by the line immunoassay. HCV RNA was detected in 4/408 subjects (1.0%, 95% confidence interval 0.0-1.9%), comprising 3/236 (1.3%; 0.0-2.8%) HBsAg-positive and 1/172 (0.6%; 0.0-1.8%) HBsAg-negative subjects. HCV RNA-positive subjects showed reactivity in all three antibody screening assays. Among HCV RNA-negative subjects, 5/67 (7.5%), 5/67 (7.5%) and 19/67 (28.4%) showed antibody reactivity by each screening assay, respectively, including two (3.0%) with reactivity by all three assays. Only one sample (1.5%) had confirmed antibody reactivity by line immunoassay indicating past HCV infection. HCV-positive subjects (three males, two females) were aged 30-46 years, by questionnaire-based interview reported surgical procedures and blood transfusion as risk factors for infection. HCV genotypes were 2 (subtypes 2j, 2l, 2k/unassigned) and 1 (subtype unassigned). Without further testing, HCV antibody screening assays variably overestimated HCV prevalence among HIV-infected subjects in Ghana. These findings inform the interpretation of previous seroprevalence estimates based upon screening assays alone.

  1. Lactose and galactose content in cheese results in overestimation of moisture by vacuum oven and microwave methods. (United States)

    Lee, H; Rankin, S A; Fonseca, L M; Milani, F X


    Moisture determination in cheese is a critical test for regulatory compliance, functionality, and economic reasons. Common methods for moisture determination in cheese rely upon the thermal volatilization of water from cheese and calculation of moisture content based on the resulting loss of mass. Residual sugars, such as lactose and galactose, are commonly present in cheeses at levels ranging from trace amounts to 5%. These sugars are capable of reacting with other compounds in cheese, especially under the thermal conditions required for moisture determination, to yield volatile reaction products. The hypothesis of this work is that residual sugars in cheese will be converted into volatile compounds over the course of moisture determination at a level sufficient to result in overestimated cheese moisture. A full-factorial statistical design was used to evaluate the effects of cheese type, sugar type, sugar level, method type, and all interactions. Cheddar and low-moisture, part-skim (LMPS) Mozzarella cheeses were prepared with 1, 3, and 5% added lactose or galactose, and subjected to either vacuum oven or microwave-based moisture determination methods. Browning index and colorimetry were measured to characterize the color and extent of browning. Volatile analyses were performed to provide chemical evidence of the reactions proposed. The presence of residual sugars altered moisture calculations as a function of cheese type, sugar type, sugar level, method type, and numerous interactions. At higher concentrations of residual sugar, the percentage moisture determinations were increased by values of up to 1.8. Measures of browning reactions, including browning index, colorimetry, and volatile profiles demonstrate that the proposed browning reactions played a causative role. This work establishes the need to consider cheese type, sugar type, sugar levels, and method type as a means of more accurately determining moisture levels.

  2. Overestimation and Underestimation: Adolescents' Weight Perception in Comparison to BMI-Based Weight Status and How It Varies across Socio-Demographic Factors (United States)

    Park, Eunkyung


    Background: Weight perception has been studied with a limited focus on "feeling overweight." This study, using a more inclusive definition of overestimation and underestimation, examines adolescents' weight perception focusing on how accurate it is in relation to body mass index (BMI)-based weight status and how it varies across socio-demographic…

  3. How significant is the slope of the sea-side boundary for modelling seawater intrusion in coastal aquifers? (United States)

    Walther, Marc; Graf, Thomas; Kolditz, Olaf; Liedl, Rudolf; Post, Vincent


    Application of numerical models is a common method to assess groundwater resources. The versatility of these models allows consideration of different levels of complexity, but the accuracy of the outcomes hinges upon a proper description of the system behaviour. In seawater intrusion assessment, the implementation of the sea-side boundary condition is of particular importance. We evaluate the influence of the slope of the sea-side boundary on the simulation results of seawater intrusion in a freshwater aquifer by employing a series of slope variations together with a sensitivity analysis by varying additional sensitive parameters (freshwater inflow and longitudinal and transverse dispersivities). Model results reveal a multi-dimensional dependence of the investigated variables with an increasing relevance of the sea-side boundary slope for seawater intrusion (decrease of up to 32%), submarine groundwater discharge zone (reduction of up to 55%), and turnover times (increase of up to 730%) with increasing freshwater inflow or dispersivity values.

  4. Investigation of the chromosome regions with significant affinity for the nuclear envelope in fruit fly--a model based approach.

    Directory of Open Access Journals (Sweden)

    Nicholas Allen Kinney

    Full Text Available Three dimensional nuclear architecture is important for genome function, but is still poorly understood. In particular, little is known about the role of the "boundary conditions"--points of attachment between chromosomes and the nuclear envelope. We describe a method for modeling the 3D organization of the interphase nucleus, and its application to analysis of chromosome-nuclear envelope (Chr-NE attachments of polytene (giant chromosomes in Drosophila melanogaster salivary glands. The model represents chromosomes as self-avoiding polymer chains confined within the nucleus; parameters of the model are taken directly from experiment, no fitting parameters are introduced. Methods are developed to objectively quantify chromosome territories and intertwining, which are discussed in the context of corresponding experimental observations. In particular, a mathematically rigorous definition of a territory based on convex hull is proposed. The self-avoiding polymer model is used to re-analyze previous experimental data; the analysis suggests 33 additional Chr-NE attachments in addition to the 15 already explored Chr-NE attachments. Most of these new Chr-NE attachments correspond to intercalary heterochromatin--gene poor, dark staining, late replicating regions of the genome; however, three correspond to euchromatin--gene rich, light staining, early replicating regions of the genome. The analysis also suggests 5 regions of anti-contact, characterized by aversion for the NE, only two of these correspond to euchromatin. This composition of chromatin suggests that heterochromatin may not be necessary or sufficient for the formation of a Chr-NE attachment. To the extent that the proposed model represents reality, the confinement of the polytene chromosomes in a spherical nucleus alone does not favor the positioning of specific chromosome regions at the NE as seen in experiment; consequently, the 15 experimentally known Chr-NE attachment positions do not

  5. Improving winter leaf area index estimation in evergreen coniferous forests and its significance in carbon and water fluxes modeling (United States)

    Wang, R.; Chen, J. M.; Luo, X.


    Modeling of carbon and water fluxes at the continental and global scales requires remotely sensed LAI as inputs. For evergreen coniferous forests (ENF), severely underestimated winter LAI has been one of the issues for mostly available remote sensing products, which could cause negative bias in the modeling of Gross Primary Productivity (GPP) and evapotranspiration (ET). Unlike deciduous trees which shed all the leaves in winter, conifers retains part of their needles and the proportion of the retained needles depends on the needle longevity. In this work, the Boreal Ecosystem Productivity Simulator (BEPS) was used to model GPP and ET at eight FLUXNET Canada ENF sites. Two sets of LAI were used as the model inputs: the 250m 10-day University of Toronto (U of T) LAI product Version 2 and the corrected LAI based on the U of T LAI product and the needle longevity of the corresponding tree species at individual sites. Validating model daily GPP (gC/m2) against site measurements, the mean RMSE over eight sites decreases from 1.85 to 1.15, and the bias changes from -0.99 to -0.19. For daily ET (mm), mean RMSE decreases from 0.63 to 0.33, and the bias changes from -0.31 to -0.16. Most of the improvements occur in the beginning and at the end of the growing season when there is large correction of LAI and meanwhile temperature is still suitable for photosynthesis and transpiration. For the dormant season, the improvement in ET simulation mostly comes from the increased interception of precipitation brought by the elevated LAI during that time. The results indicate that model performance can be improved by the application the corrected LAI. Improving the winter RS LAI can make a large impact on land surface carbon and energy budget.

  6. Segmentation process significantly influences the accuracy of 3D surface models derived from cone beam computed tomography

    NARCIS (Netherlands)

    Fourie, Zacharias; Damstra, Janalt; Schepers, Rutger H; Gerrits, Pieter; Ren, Yijin


    AIMS: To assess the accuracy of surface models derived from 3D cone beam computed tomography (CBCT) with two different segmentation protocols. MATERIALS AND METHODS: Seven fresh-frozen cadaver heads were used. There was no conflict of interests in this study. CBCT scans were made of the heads and 3D

  7. Increased blood glycohemoglobin A1c levels lead to overestimation of arterial oxygen saturation by pulse oximetry in patients with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Pu Li


    Full Text Available Abstract Background Non-enzymatic glycation increases hemoglobin-oxygen affinity and reduces oxygen delivery to tissues by altering the structure and function of hemoglobin. Objectives We investigated whether an elevated blood concentration of glycosylated hemoglobin (HbA1c could induce falsely high pulse oximeter oxygen saturation (SpO2 in type 2 diabetic patients during mechanical ventilation or oxygen therapy. Methods Arterial oxygen saturation (SaO2 and partial pressure of oxygen (PO2 were determined with simultaneous monitoring of SpO2 in 261 type 2 diabetic patients during ventilation or oxygen inhalation. Results Blood concentration of HbA1c was >7% in 114 patients and ≤ 7% in 147 patients. Both SaO2 (96.2 ± 2.9%, 95% confidence interval [CI] 95.7-96.7% vs. 95.1 ± 2.8%, 95% CI 94.7-95.6% and SpO2 (98.0 ± 2.6%, 95% CI 97.6-98.5% vs. 95.3 ± 2.8%, 95% CI 94.9-95.8% were significantly higher in patients with HbA1c >7% than in those with HbA1c ≤ 7% (Data are mean ± SD, all p 2 did not significantly differ between the two groups. Bland-Altman analysis demonstrated a significant bias between SpO2 and SaO2 (1.83 ±0.55%, 95% CI 1.73% -1.94% and limits of agreement (0.76% and 2.92% in patients with HbA1c >7%. The differences between SpO2 and SaO2 correlated closely with blood HbA1c levels (Pearson’s r = 0.307, p  Conclusions Elevated blood HbA1c levels lead to an overestimation of SaO2 by SpO2, suggesting that arterial blood gas analysis may be needed for type 2 diabetic patients with poor glycemic control during the treatment of hypoxemia.

  8. Significance of the spatial reconstruction based on mathematical modeling in the surgical treatment of giant intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    Nikolić Igor M.


    Full Text Available Background. The use of computer models for the 3- dimensional reconstruction could be a reliable method to overcome technical imperfections of diagnostic procedures for the microsurgical operation of giant intracranial aneurysms. Case report. We presented a case of successfully operated 52-year-old woman with giant intracranial aneurysm, in which the computer 3-dimensional reconstruction of blood vessels and the aneurysmal neck had been decisive for making the diagnosis. The model for 3- dimensional reconstruction of blood vessels was based on the two 2-dimensional projections of the conventional angiography. Standard neuroradiologic diagnostic procedures showed a giant aneurysm on the left middle cerebral artery, but the conventional subtraction and CT angiography did not reveal enough information. By the use of a personal computer, we performed a 3-dimensional spatial reconstruction of the left carotid artery to visualize the neck of aneurysm and its supplying blood vessels. Conclusion. The 3-dimensional spatial reconstruction of the cerebral vessels of a giant aneurysm based on the conventional angiography could be useful for planning the surgical procedure.

  9. Acellular bone marrow extracts significantly enhance engraftment levels of human hematopoietic stem cells in mouse xeno-transplantation models.

    Directory of Open Access Journals (Sweden)

    Kazem Zibara

    Full Text Available Hematopoietic stem cells (HSC derived from cord blood (CB, bone marrow (BM, or mobilized peripheral blood (PBSC can differentiate into multiple lineages such as lymphoid, myeloid, erythroid cells and platelets. The local microenvironment is critical to the differentiation of HSCs and to the preservation of their phenotype in vivo. This microenvironment comprises a physical support supplied by the organ matrix as well as tissue specific cytokines, chemokines and growth factors. We investigated the effects of acellular bovine bone marrow extracts (BME on HSC in vitro and in vivo. We observed a significant increase in the number of myeloid and erythroid colonies in CB mononuclear cells (MNC or CB CD34+ cells cultured in methylcellulose media supplemented with BME. Similarly, in xeno-transplantation experiments, pretreatment with BME during ex-vivo culture of HSCs induced a significant increase in HSC engraftment in vivo. Indeed, we observed both an increase in the number of differentiated myeloid, lymphoid and erythroid cells and an acceleration of engraftment. These results were obtained using CB MNCs, BM MNCs or CD34(+ cells, transplanted in immuno-compromised mice (NOD/SCID or NSG. These findings establish the basis for exploring the use of BME in the expansion of CB HSC prior to HSC Transplantation. This study stresses the importance of the mechanical structure and soluble mediators present in the surrounding niche for the proper activity and differentiation of stem cells.

  10. Dual learning processes underlying human decision-making in reversal learning tasks: Functional significance and evidence from the model fit to human behavior

    Directory of Open Access Journals (Sweden)

    Yu eBai


    Full Text Available Humans are capable of correcting their actions based on actions performed in the past, and this ability enables them to adapt to a changing environment. The computational field of reinforcement learning (RL has provided a powerful explanation for understanding such processes. Recently, the dual learning system, modeled as a hybrid model that incorporates value update based on reward-prediction error and learning rate modulation based on the surprise signal, has gained attention as a model for explaining various neural signals. However, the functional significance of the hybrid model has not been established. In the present study, we used computer simulation in a reversal learning task to address functional significance. The hybrid model was found to perform better than the standard RL model in a large parameter setting. These results suggest that the hybrid model is more robust against mistuning of parameters compared to the standard RL model when decision makers continue to learn stimulus-reward contingencies, which make an abrupt changes. The parameter fitting results also indicated that the hybrid model fit better than the standard RL model for more than 50% of the participants, which suggests that the hybrid model has more explanatory power for the behavioral data than the standard RL model.

  11. [Different explanatory models for addictive behavior in Turkish and German youths in Germany: significance for prevention and treatment]. (United States)

    Penka, S; Krieg, S; Hunner, Ch; Heinz, A


    Due to cultural and social barriers, immigrants seldom frequent centers for information, counseling, and treatment of addictive disorders. We examine cultural differences in the explanatory models of addictive behavior among Turkish and German youths in Germany with statistical devices that map the concepts associated with problems of addiction. Relevant differences were found between the disorder concepts of Turkish and German youth. German but not Turkish youths classified eating disorders among severe addictive disorders and associated them with embarrassment and shame. Concerning substance abuse, German but not Turkish youths clearly differentiated between illegal drug abuse and the abuse of alcohol and nicotine. Nearly half of all Turkish youths rejected central medical concepts such as "physical dependence" or "reduced control of substance intake" as completely inadequate to characterize problems of addictive behavior. Preventive information programs must consider these differences and use concepts that are accepted and clearly associated with addictive behavior by immigrant populations.

  12. Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season (United States)

    Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard


    Although maize is the second most important crop worldwide, and the most important C4 crop, no study on biogenic volatile organic compounds (BVOCs) has yet been conducted on this crop at ecosystem scale and over a whole growing season. This has led to large uncertainties in cropland BVOC emission estimations. This paper seeks to fill this gap by presenting, for the first time, BVOC fluxes measured in a maize field at ecosystem scale (using the disjunct eddy covariance by mass scanning technique) over a whole growing season in Belgium. The maize field emitted mainly methanol, although exchanges were bi-directional. The second most exchanged compound was acetic acid, which was taken up mainly in the growing season. Bi-directional exchanges of acetaldehyde, acetone and other oxygenated VOCs also occurred, whereas the terpenes, benzene and toluene exchanges were small, albeit significant. Surprisingly, BVOC exchanges were of the same order of magnitude on bare soil and on well developed vegetation, suggesting that soil is a major BVOC reservoir in agricultural ecosystems. Quantitatively, the maize BVOC emissions observed were lower than those reported in other maize, crops and grasses studies. The standard emission factors (SEFs) estimated in this study (231 ± 19 µg m-2 h-1 for methanol, 8 ± 5 µg m-2 h-1 for isoprene and 4 ± 6 µg m-2 h-1 for monoterpenes) were also much lower than those currently used by models for C4 crops, particularly for terpenes. These results suggest that maize fields are small BVOC exchangers in north-western Europe, with a lower BVOC emission impact than that modelled for growing C4 crops in this part of the world. They also reveal the high variability in BVOC exchanges across world regions for maize and suggest that SEFs should be estimated for each region separately.

  13. Control of anticoagulation with vitamin K antagonists: overestimation of median time in therapeutic range when assessed by linear interpolation. (United States)

    van den Besselaar, A M H P; Biedermann, Joseph S; van der Meer, Felix J M; Adriaansen, Henk J; Leebeek, Frank W G; Kruip, Marieke J H A


    Patients receiving vitamin K-antagonists are monitored by regular assessment of the International Normalized Ratio (INR). There are two popular methods for therapeutic control of anticoagulation in patient groups: 1) Time in Therapeutic Range (TTR) assessed by linear interpolation of successive INR measurements; 2) the cross-sectional proportion (CSP) of all patients' last INRs within range. The purpose of the present study is to compare the two methods using data from 53 Dutch Thrombosis Centres and to develop a semi-quantitative model for TTR based on different types of INR change. Different groups of around 400,000 patients in four consecutive years were evaluated: patients in the induction phase, short-term, long-term, low-target range, high-target range, receiving either acenocoumarol or phenprocoumon, and performing self-management. Each Centre provided TTR and CSP results for each patient group. TTR and CSP were compared using the Wilcoxon signed-rank test. Separately, we analysed the relationship between consecutive INR results regarding in or out of range and their frequency of occurrence in patients of two different cohorts. Good correlation was observed between TTR and CSP (correlation coefficient 0.694-0.950 in low-target range). In long-term acenocoumarol patients (low-target range) the median TTR was significantly higher than CSP (80.0 % and 78.7 %, respectively; prange) there was no significant difference between median TTR (83.0 %) and median CSP (82.6 %). In conclusion, the correlation between TTR assessed by linear interpolation and CSP was good. TTR assessed by linear interpolation was higher than CSP in patients on acenocoumarol.

  14. Significance of plankton community structure and nutrient availability for the control of dinoflagellate blooms by parasites: a modeling approach. (United States)

    Alves-de-Souza, Catharina; Pecqueur, David; Le Floc'h, Emilie; Mas, Sébastien; Roques, Cécile; Mostajir, Behzad; Vidussi, Franscesca; Velo-Suárez, Lourdes; Sourisseau, Marc; Fouilland, Eric; Guillou, Laure


    Dinoflagellate blooms are frequently observed under temporary eutrophication of coastal waters after heavy rains. Growth of these opportunistic microalgae is believed to be promoted by sudden input of nutrients and the absence or inefficiency of their natural enemies, such as grazers and parasites. Here, numerical simulations indicate that increasing nutrient availability not only promotes the formation of dinoflagellate blooms but can also stimulate their control by protozoan parasites. Moreover, high abundance of phytoplankton other than dinoflagellate hosts might have a significant dilution effect on the control of dinoflagellate blooms by parasites, either by resource competition with dinoflagellates (thus limiting the number of hosts available for infection) or by affecting numerical-functional responses of grazers that consume free-living parasite stages. These outcomes indicate that although both dinoflagellates and their protozoan parasites are directly affected by nutrient availability, the efficacy of the parasitic control of dinoflagellate blooms under temporary eutrophication depends strongly on the structure of the plankton community as a whole.

  15. Improving CCTA-based lesions' hemodynamic significance assessment by accounting for partial volume modeling in automatic coronary lumen segmentation. (United States)

    Freiman, Moti; Nickisch, Hannes; Prevrhal, Sven; Schmitt, Holger; Vembar, Mani; Maurovich-Horvat, Pál; Donnelly, Patrick; Goshen, Liran


    The goal of this study was to assess the potential added benefit of accounting for partial volume effects (PVE) in an automatic coronary lumen segmentation algorithm that is used to determine the hemodynamic significance of a coronary artery stenosis from coronary computed tomography angiography (CCTA). Two sets of data were used in our work: (a) multivendor CCTA datasets of 18 subjects from the MICCAI 2012 challenge with automatically generated centerlines and 3 reference segmentations of 78 coronary segments and (b) additional CCTA datasets of 97 subjects with 132 coronary lesions that had invasive reference standard FFR measurements. We extracted the coronary artery centerlines for the 97 datasets by an automated software program followed by manual correction if required. An automatic machine-learning-based algorithm segmented the coronary tree with and without accounting for the PVE. We obtained CCTA-based FFR measurements using a flow simulation in the coronary trees that were generated by the automatic algorithm with and without accounting for PVE. We assessed the potential added value of PVE integration as a part of the automatic coronary lumen segmentation algorithm by means of segmentation accuracy using the MICCAI 2012 challenge framework and by means of flow simulation overall accuracy, sensitivity, specificity, negative and positive predictive values, and the receiver operated characteristic (ROC) area under the curve. We also evaluated the potential benefit of accounting for PVE in automatic segmentation for flow simulation for lesions that were diagnosed as obstructive based on CCTA which could have indicated a need for an invasive exam and revascularization. Our segmentation algorithm improves the maximal surface distance error by ~39% compared to previously published method on the 18 datasets from the MICCAI 2012 challenge with comparable Dice and mean surface distance. Results with and without accounting for PVE were comparable. In contrast

  16. {sup 99m}Tc-MAA overestimates the absorbed dose to the lungs in radioembolization: a quantitative evaluation in patients treated with {sup 166}Ho-microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Elschot, Mattijs; Nijsen, Johannes F.W.; Lam, Marnix G.E.H.; Smits, Maarten L.J.; Prince, Jip F.; Bosch, Maurice A.A.J. van den; Zonnenberg, Bernard A.; Jong, Hugo W.A.M. de [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Viergever, Max A. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)


    scintigraphy (median 5.5 Gy, range 2.3 to 18.2 Gy; p < 0.001). In clinical practice, lung absorbed doses are significantly overestimated by pretreatment diagnostic {sup 99m}Tc-MAA imaging. Pretreatment diagnostic {sup 166}Ho-microsphere SPECT/CT imaging accurately predicts lung absorbed doses after {sup 166}Ho radioembolization. (orig.)

  17. Surface functionalization of bioactive glasses with natural molecules of biological significance, Part I: Gallic acid as model molecule (United States)

    Zhang, Xin; Ferraris, Sara; Prenesti, Enrico; Verné, Enrica


    Gallic acid (3,4,5-trihydroxybenzoic acid, GA) and its derivatives are a group of biomolecules (polyphenols) obtained from plants. They have effects which are potentially beneficial to heath, for example they are antioxidant, anticarcinogenic and antibacterial, as recently investigated in many fields such as medicine, food and plant sciences. The main drawbacks of these molecules are both low stability and bioavailability. In this research work the opportunity to graft GA to bioactive glasses is investigated, in order to deliver the undamaged biological molecule into the body, using the biomaterial surfaces as a localized carrier. GA was considered for functionalization since it is a good model molecule for polyphenols and presents several interesting biological activities, like antibacterial, antioxidant and anticarcinogenic properties. Two different silica based bioactive glasses (SCNA and CEL2), with different reactivity, were employed as substrates. UV photometry combined with the Folin&Ciocalteu reagent was adopted to test the concentration of GA in uptake solution after functionalization. This test verified how much GA consumption occurred with surface modification and it was also used on solid samples to test the presence of GA on functionalized glasses. XPS and SEM-EDS techniques were employed to characterize the modification of material surface properties and functional group composition before and after functionalization.

  18. Elucidating the significance of spatial memory on movement decisions by African savannah elephants using state-space models. (United States)

    Polansky, Leo; Kilian, Werner; Wittemyer, George


    Spatial memory facilitates resource acquisition where resources are patchy, but how it influences movement behaviour of wide-ranging species remains to be resolved. We examined African elephant spatial memory reflected in movement decisions regarding access to perennial waterholes. State-space models of movement data revealed a rapid, highly directional movement behaviour almost exclusively associated with visiting perennial water. Behavioural change point (BCP) analyses demonstrated that these goal-oriented movements were initiated on average 4.59 km, and up to 49.97 km, from the visited waterhole, with the closest waterhole accessed 90% of the time. Distances of decision points increased when switching to different waterholes, during the dry season, or for female groups relative to males, while selection of the closest waterhole decreased when switching. Overall, our analyses indicated detailed spatial knowledge over large scales, enabling elephants to minimize travel distance through highly directional movement when accessing water. We discuss the likely cognitive and socioecological mechanisms driving these spatially precise movements that are most consistent with our findings. By applying modern analytic techniques to high-resolution movement data, this study illustrates emerging approaches for studying how cognition structures animal movement behaviour in different ecological and social contexts. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  19. Stress field modeling of northwestern South China Sea since 5.3 Ma and its tectonic significance

    Institute of Scientific and Technical Information of China (English)

    YANG Fengli; ZHOU Zuyi; ZHANG Na; LIU Ning; NI Bin


    Tectonically, the northwestern South China Sea (SCS) is located at the junction between three micro-plates, i.e., the Indochina, South China and Zhongsha-Xisha micro-plates, and involves three basins, i.e., the Yinggehai Basin, the Qiongdongnan Basin and Xisha Trough in the east, and the Zhongjiannan Basin in the south. Since the Pliocene (5.3 Ma), the Yinggehai Basin has experienced repeated accelerating subsidence, high thermal fluid, and widely developing mud-rich overpressure chambers, abundant mud diapers and crust-mantle mixed CO2. While a large central canyon was developed in the Qiongdongnan Basin, new rift occurred in the Xisha Trough. These characteristics demonstrate a single tectonic unit for the northwestern SCS, for which we have undertaken stress field modeling to understand its plate deformations and sedimen-tary responses. Our results demonstrate that an extension tectonic event occurred after 5.3 Ma in theYingge-hai-Qiongdongnan-Xisha trough area, which is characterized by thinner crust (3500 m). A new rift system subsequently was developed in this area;this event was mainly driven by the combined effects of different movement veloc-ity and direction of the three micro-plates, and the far-field effect of the continental collision between the Indian Plate and the Tibetan Plateau, and subduction of the Pacific Plate underneath the Eurasian Plate.

  20. Inhibition of tumor progression during allergic airway inflammation in a murine model: significant role of TGF-β. (United States)

    Tirado-Rodriguez, Belen; Baay-Guzman, Guillermina; Hernandez-Pando, Rogelio; Antonio-Andres, Gabriela; Vega, Mario I; Rocha-Zavaleta, Leticia; Bonifaz, Laura C; Huerta-Yepez, Sara


    TGF-β is an important mediator of pulmonary allergic inflammation, and it has been recently reported to be a potential inhibitor of lung tumor progression. The correlation between cancer and allergic inflammatory diseases remains controversial. Thus, the aim of the present study was to evaluate the effects of pulmonary allergic inflammation and in particular the role of TGF-β on cancer progression. Cancer cells were implanted in a BALB/c mice model of allergic airway inflammation, and tumor growth was measured. Apoptosis was evaluated by TUNEL assay, and TGF-β was measured by ELISA. Expression of proliferating cell nuclear antigen, TGF-β, TGF-β receptors I and II, phospho-Smad2 and phospho-Smad4 was evaluated by immunohistochemistry and quantified using digital pathology. The effect of a TGF-β activity inhibitor and recombinant TGF-β on tumor growth was analyzed. The effect of exogenous TGF-β on cell proliferation and apoptosis was evaluated in vitro. Mice with allergic airway inflammation exhibited decreased tumor volumes due to cell proliferation inhibition and increased apoptosis. TGF-β was increased in the sera and tumor tissues of allergic mice. TGF-β activity inhibition increased tumor progression in allergic mice by enhancing proliferation and decreasing apoptosis of tumor cells. The administration of TGF-β resulted in reduced tumor growth. This study is the first to establish an inverse relationship between allergic airway inflammation and tumor progression. This effect appears to be mediated by TGF-β, which is overexpressed in tumor cells during pulmonary allergic inflammation. This study indicates that TGF-β is a potential target for antitumor therapy.

  1. The effect of c-fos on acute myocardial infarction and the significance of metoprolol intervention in a rat model. (United States)

    Zhang, Song; Zhang, Meiqi; Goldstein, Steven; Li, Yigang; Ge, Junbo; He, Ben; Ruiz, George


    Over-expression of c-fos may play a role in some diseases. Research pertaining to the expression of c-fos in acute myocardial ınfarction (AMI) is rare, and the detailed role of c-fos in AMI has not been reported. Therefore, the purpose of this project was to elucidate the detailed effect of c-fos on AMI rats and evaluate the effect of a metoprolol intervention. An AMI rat model was established for the purposes of this study. The expression of c-fos in AMI was evaluated via immunohistochemical analysis and in situ hybridization. Simultaneously, we investigated the effect of c-fos on AMI rats via medicinal treatment with c-fos monoclonal antibody, isoproterenol, and metoprolol. Positive c-Fos protein expression and c-fos mRNA expression in cardiomyocytes were increased at 1, 3, 7, and 10 days after ligation in AMI rats compared with a sham-operated group. Peak expression occurred at 3 days after ligation. The weight percentage fraction of infarct size was decreased in rats treated with c-fos monoclonal antibody compared with the control normal saline treatment group. The weight percentage fraction of infarction size was increased after c-fos was increased via the administration of isoproterenol. c-Fos protein expression and the infarct size in rats treated with metoprolol were also decreased compared with the control normal saline treatment group. The results showed that c-fos expression rapidly increased after coronary ligation; c-fos plays an important role in myocardial lesions and is likely to be involved in the pathogenesis of AMI as well. Metoprolol can inhibit the expression of c-fos and has a positive therapeutic effect on rats after AMI; the involvement effect of metoprolol on myocardial infarction might be correlated with its effect on the inhibition of c-fos.

  2. The Significance of Quality Assurance within Model Intercomparison Projects at the World Data Centre for Climate (WDCC) (United States)

    Toussaint, F.; Hoeck, H.; Stockhause, M.; Lautenschlager, M.


    The classical goals of a quality assessment system in the data life cycle are (1) to encourage data creators to improve their quality assessment procedures to reach the next quality level and (2) enable data consumers to decide, whether a dataset has a quality that is sufficient for usage in the target application, i.e. to appraise the data usability for their own purpose.As the data volumes of projects and the interdisciplinarity of data usage grow, the need for homogeneous structure and standardised notation of data and metadata increases. This third aspect is especially valid for the data repositories, as they manage data through machine agents. So checks for homogeneity and consistency in early parts of the workflow become essential to cope with today's data volumes.Selected parts of the workflow in the model intercomparison project CMIP5 and the archival of the data for the interdiscipliary user community of the IPCC-DDC AR5 and the associated quality checks are reviewed. We compare data and metadata checks and relate different types of checks to their positions in the data life cycle.The project's data citation approach is included in the discussion, with focus on temporal aspects of the time necessary to comply with the project's requirements for formal data citations and the demand for the availability of such data citations.In order to make different quality assessments of projects comparable, WDCC developed a generic Quality Assessment System. Based on the self-assessment approach of a maturity matrix, an objective and uniform quality level system for all data at WDCC is derived which consists of five maturity quality levels.

  3. Macrophytes may not contribute significantly to removal of nutrients, pharmaceuticals, and antibiotic resistance in model surface constructed wetlands. (United States)

    Cardinal, Pascal; Anderson, Julie C; Carlson, Jules C; Low, Jennifer E; Challis, Jonathan K; Beattie, Sarah A; Bartel, Caitlin N; Elliott, Ashley D; Montero, Oscar F; Lokesh, Sheetal; Favreau, Alex; Kozlova, Tatiana A; Knapp, Charles W; Hanson, Mark L; Wong, Charles S


    Outdoor shallow wetland mesocosms, designed to simulate surface constructed wetlands to improve lagoon wastewater treatment, were used to assess the role of macrophytes in the dissipation of wastewater nutrients, selected pharmaceuticals, and antibiotic resistance genes (ARGs). Specifically, mesocosms were established with or without populations of Typha spp. (cattails), Myriophyllum sibiricum (northern water milfoil), and Utricularia vulgaris (bladderwort). Following macrophyte establishment, mesocosms were seeded with ARG-bearing organisms from a local wastewater lagoon, and treated with a single pulse of artificial municipal wastewater with or without carbamazepine, clofibric acid, fluoxetine, and naproxen (each at 7.6μg/L), as well as sulfamethoxazole and sulfapyridine (each at 150μg/L). Rates of pharmaceutical dissipation over 28d ranged from 0.073 to 3.0d(-1), corresponding to half-lives of 0.23 to 9.4d. Based on calculated rate constants, observed dissipation rates were consistent with photodegradation driving clofibric acid, naproxen, sulfamethoxazole, and sulfapyridine removal, and with sorption also contributing to carbamazepine and fluoxetine loss. Of the seven gene determinants assayed, only two genes for both beta-lactam resistance (blaCTX and blaTEM) and sulfonamide resistance (sulI and sulII) were found in sufficient quantity for monitoring. Genes disappeared relatively rapidly from the water column, with half-lives ranging from 2.1 to 99d. In contrast, detected gene levels did not change in the sediment, with the exception of sulI, which increased after 28d in pharmaceutical-treated systems. These shallow wetland mesocosms were able to dissipate wastewater contaminants rapidly. However, no significant enhancement in removal of nutrients or pharmaceuticals was observed in mesocosms with extensive aquatic plant communities. This was likely due to three factors: first, use of naïve systems with an unchallenged capacity for nutrient assimilation and

  4. Intra-articular (IA) ropivacaine microparticle suspensions reduce pain, inflammation, cytokine, and substance p levels significantly more than oral or IA celecoxib in a rat model of arthritis. (United States)

    Rabinow, Barrett; Werling, Jane; Bendele, Alison; Gass, Jerome; Bogseth, Roy; Balla, Kelly; Valaitis, Paul; Hutchcraft, Audrey; Graham, Sabine


    Current therapeutic treatment options for osteoarthritis entail significant safety concerns. A novel ropivacaine crystalline microsuspension for bolus intra-articular (IA) delivery was thus developed and studied in a peptidoglycan polysaccharide (PGPS)-induced ankle swelling rat model. Compared with celecoxib controls, both oral and IA, ropivacaine IA treatment resulted in a significant reduction of pain upon successive PGPS reactivation, as demonstrated in two different pain models, gait analysis and incapacitance testing. The reduction in pain was attended by a significant reduction in histological inflammation, which in turn was accompanied by significant reductions in the cytokines IL-18 and IL-1β. This may have been due to inhibition of substance P, which was also significantly reduced. Pharmacokinetic analysis indicated that the analgesic effects outlasted measurable ropivacaine levels in either blood or tissue. The results are discussed in the context of pharmacologic mechanisms both of local anesthetics as well as inflammatory arthritis.

  5. Overestimation of soil CO2 fluxes from closed chamber measurements at low atmospheric turbulence biases the diurnal pattern and the annual soil respiration budget (United States)

    Braendholt, Andreas; Steenberg Larsen, Klaus; Ibrom, Andreas; Pilegaard, Kim


    Precise quantification of the diurnal and seasonal variation of soil respiration (Rs) is crucial to correctly estimate annual soil carbon fluxes as well as to correctly interpret the response of Rs to biotic and abiotic factors on different time scale. In this study we found a systematic effect of low atmospheric turbulence on continuous hourly Rs measurements with closed chambers throughout one year in a temperate Danish beech forest. Using friction velocity (u⋆) measured at the site above the canopy, we filtered out chamber flux data measured at low atmospheric turbulence. The non-filtered data showed a clear diurnal pattern of Rs across all seasons with highest fluxes during night time suggesting an implausible negative temperature sensitivity of Rs. When filtering out data at low turbulence, the annually averaged diurnal pattern changed, such that the highest Rs fluxes were seen during day time, i.e. following the course of soil temperatures. This effect on the diurnal pattern was due to low turbulence primarily occurring during night time. We calculated different annual Rs budgets by filtering out fluxes for different levels of u⋆. The highest annual Rs budget was found when including all data and it decreased with an increasing u⋆ filter threshold. Our results show that Rs was overestimated at low atmospheric turbulence throughout the year and that this overestimation considerably biased the diurnal pattern of Rs and led to an overestimation of the annual Rs budget. Thus we recommend that that any analysis of the diurnal pattern of Rs must consider overestimation of Rs at low atmospheric turbulence, to yield unbiased diurnal patterns. This is crucial when investigating temperature responses and potential links between CO2 production and Rs on a short time scale, but also for correct estimation of annual Rs budgets. Acknowledgements: This study was funded by the free Danish Ministry for Research, Innovation and higher Education, the free Danish Research

  6. Acute hypothalamic suppression significantly affects trabecular bone but not cortical bone following recovery and ovariectomy surgery in a rat model

    Directory of Open Access Journals (Sweden)

    Vanessa R. Yingling


    RH-a group compared to C, a similar deficit in BV/TV was also measured following recovery and post-OVX. The trabecular number and thickness were lower in the GnRH-a group compared to control.Conclusion. These data suggest that following a transient delay in pubertal onset, trabecular bone volume was significantly lower and no restoration of bone volume occurred following recovery or post-OVX surgery. However, cortical bone strength was maintained through architectural adaptations in the cortical bone envelope. An increase in the polar moment of inertia offset increased bone resorption. The current data are the first to suppress trabecular bone during growth, and then add an OVX protocol at maturity. Trabecular bone and cortical bone differed in their response to hypothalamic suppression during development; trabecular bone was more sensitive to the negative effects of hypothalamic suppression.

  7. Overestimation of vitamin a supplementation coverage from district tally sheets demonstrates importance of population-based surveys for program improvement: lessons from Tanzania.

    Directory of Open Access Journals (Sweden)

    Christina Nyhus Dhillon

    Full Text Available BACKGROUND: Tanzania has conducted a national twice-yearly Vitamin A supplementation (VAS campaign since 2001. Administrative coverage rates based on tally sheets consistently report >90% coverage; however the accuracy of these rates are uncertain due to potential errors in tally sheets and their aggregation, incomplete or inaccurate reporting from distribution sites, and underestimating the target population. OBJECTIVES: The post event coverage survey in Mainland Tanzania sought to validate tally-sheet based national coverage estimates of VAS and deworming for the June 2010 mass distribution round, and to characterize children missed by the national campaign. METHODS: WHO/EPI randomized cross-sectional cluster sampling methodology was adapted for this study, using 30 clusters by 40 individuals (n = 1200, in addition to key informant interviews. Households with children 6-59 months of age were included in the study (12-59 months for deworming analysis. Chi-squared tests and logistic regression analysis were used to test differences between children reached and not reached by VAS. Data was collected within six weeks of the June 2010 round. RESULTS: A total of 1203 children, 58 health workers, 30 village leaders and 45 community health workers were sampled. Preschool VAS coverage was 65% (95% CI: 62.7-68.1, approximately 30% lower than tally-sheet coverage estimates. Factors associated with not receiving VAS were urban residence [OR = 3.31; p = 0.01], caretakers who did not hear about the campaign [OR = 48.7; p<0.001], and Muslim households [OR<3.25; p<0.01]. There were no significant differences in VAS coverage by child sex or age, or maternal age or education. CONCLUSION: Coverage estimation for vitamin A supplementation programs is one of most powerful indicators of program success. National VAS coverage based on a tally-sheet system overestimated VAS coverage by ∼30%. There is a need for representative population

  8. End-to-end models for marine ecosystems: Are we on the precipice of a significant advance or just putting lipstick on a pig?

    Directory of Open Access Journals (Sweden)

    Kenneth A. Rose


    Full Text Available There has been a rapid rise in the development of end-to-end models for marine ecosystems over the past decade. Some reasons for this rise include need for predicting effects of climate change on biota and dissatisfaction with existing models. While the benefits of a well-implemented end-to-end model are straightforward, there are many challenges. In the short term, my view is that the major role of end-to-end models is to push the modelling community forward, and to identify critical data so that these data can be collected now and thus be available for the next generation of end-to-end models. I think we should emulate physicists and build theoretically-oriented models first, and then collect the data. In the long-term, end-to-end models will increase their skill, data collection will catch up, and end-to-end models will move towards site-specific applications with forecasting and management capabilities. One pathway into the future is individual efforts, over-promise, and repackaging of poorly performing component submodels (“lipstick on a pig”. The other pathway is a community-based collaborative effort, with appropriate caution and thoughtfulness, so that the needed improvements are achieved (“significant advance”. The promise of end-to-end modelling is great. We should act now to avoid missing a great opportunity.

  9. The global significance of omitting soil erosion from soil organic carbon cycling schemes (United States)

    Chappell, Adrian; Baldock, Jeffrey; Sanderman, Jonathan


    Soil organic carbon (SOC) cycling schemes used in land surface models (LSMs) typically account only for the effects of net primary production and heterotrophic respiration. To demonstrate the significance of omitting soil redistribution in SOC accounting, sequestration and emissions, we modified the SOC cycling scheme RothC (ref. ) to include soil erosion. Net SOC fluxes with and without soil erosion for Australian long-term trial sites were established and estimates made across Australia and other global regions based on a validated relation with catchment-scale soil erosion. Assuming that soil erosion is omitted from previous estimates of net C flux, we found that SOC erosion is incorrectly attributed to respiration. On this basis, the Australian National Greenhouse Gas inventory overestimated the net C flux from cropland by up to 40% and the potential (100 year) C sink is overestimated by up to 17%. We estimated global terrestrial SOC erosion to be 0.3-1.0 Pg C yr-1 indicating an uncertainty of -18 to -27% globally and +35 to -82% regionally relative to the long-term (2000-2010) terrestrial C flux of several LSMs. Including soil erosion in LSMs should reduce uncertainty in SOC flux estimates with implications for CO2 emissions, mitigation and adaptation strategies and interpretations of trends and variability in global ecosystems.

  10. Calculation of limits for significant unidirectional changes in two or more serial results of a biomarker based on a computer simulation model

    DEFF Research Database (Denmark)

    Lund, Flemming; Petersen, Per Hyltoft; Fraser, Callum G


    concept on more than two results will increase the number of false-positive results. Therefore, a simple method is needed to interpret the significance of a difference when all available serial biomarker results are considered. METHODS: A computer simulation model using Excel was developed. Based on 10...

  11. Using chi-Squared Automatic Interaction Detection (CHAID) modelling to identify groups of methadone treatment clients experiencing significantly poorer treatment outcomes. (United States)

    Murphy, Emma L; Comiskey, Catherine M


    In times of scarce resources it is important for services to make evidence based decisions when identifying clients with poor outcomes. chi-Squared Automatic Interaction Detection (CHAID) modelling was used to identify characteristics of clients experiencing statistically significant poor outcomes. A national, longitudinal study recruited and interviewed, using the Maudsley Addiction Profile (MAP), 215 clients starting methadone treatment and 78% were interviewed one year later. Four CHAID analyses were conducted to model the interactions between the primary outcome variable, used heroin in the last 90 days prior to one year interview and variables on drug use, treatment history, social functioning and demographics. Results revealed that regardless of these other variables, males over 22 years of age consistently demonstrated significantly poorer outcomes than all other clients. CHAID models can be easily applied by service providers to provide ongoing evidence on clients exhibiting poor outcomes and requiring priority within services.

  12. Overestimation of complication rates in evaluations of Chlamydia trachomatis screening programmes--implications for cost-effectiveness analyses.

    NARCIS (Netherlands)

    Valkengoed, van IG; Morre, S.A.; Brule, van den AJ; Meijer, C.J.L.M.; Bouter, L.M.; Boeke, AJ


    BACKGROUND: Cost-effectiveness analyses of screening programmes for asymptomatic Chlamydia trachomatis infection suggest that screening at low prevalences in the population is cost-effective. However, the decision models in these studies are based on assumptions about the risk of complications, whic

  13. Overestimation of complication rates in evaluations of Chlamydia trachomatis screening programmes--implications for cost-effectiveness analyses.

    NARCIS (Netherlands)

    Valkengoed, van IG; Morre, S.A.; Brule, van den AJ; Meijer, C.J.L.M.; Bouter, L.M.; Boeke, AJ


    BACKGROUND: Cost-effectiveness analyses of screening programmes for asymptomatic Chlamydia trachomatis infection suggest that screening at low prevalences in the population is cost-effective. However, the decision models in these studies are based on assumptions about the risk of complications,

  14. Liu et al. suspect that Zhu et al. (2015) may have underestimated dissolved organic nitrogen (N) but overestimated total particulate N in wet deposition in China. (United States)

    Liu, Xuejun; Xu, Wen; Pan, Yuepeng; Du, Enzai


    In a recent publication in the journal Science of the Total Environment, Zhu et al. (2015) reported the composition, spatial patterns, and factors influencing atmospheric wet nitrogen (N) deposition based on one year's data from 41-monitoring sites in China. We suspect their results may largely underestimate dissolved organic N (DON) but overestimate total particulate N (TPN) in wet deposition due to the uncertainty resulting from the sampling, storage and analysis methods in their study. Our suspicions are based mainly on our experience from earlier measurements and the literature. We therefore suggest that enhanced data quality control on atmospheric N deposition measurements should be taken into account in future studies.

  15. Have we been ignoring physiological plasticity and genetic variation in stomatal function as a significant source of error in models of water and carbon fluxes? (United States)

    Wertin, T. M.; Wolz, K.; Richter, K.; Adorbo, M.; Betzelberger, A. M.; Leakey, A.


    Accurately predicting plant and ecosystem function across climatic and ecological gradients requires properly parameterized models of both net photosynthetic assimilation of CO2 and stomatal conductance. Photosynthesis models have been parameterized to account for physiological plasticity and genetic variation for decades. However, models describing physiological plasticity or genetic variation in the sensitivity of stomatal conductance to net photosynthetic CO2 assimilation (A), relative humidity (RH), and atmospheric [CO2] have rarely, if ever, been applied. There is no mechanistic basis for the prevailing assumption that models of stomatal conductance can share a universal parameterization for all C3 species. Twelve species of temperate trees were grown in a common garden to test species-specific sensitivity of stomatal conductance to A, RH and [CO2]. Additionally, a Salix and a Populus genotype, grown at three locations throughout the Eastern US in biofuels trails, were measured at three times during the growing season to test for temporal and spatial effects. Soybean was also grown at eight ozone concentrations to test for physiological plasticity in stomatal function. Laboratory-based gas exchange measurements were used to parameterize the widely used Ball et al. (1987) model of stomatal conductance and the Farquhar et al. (1980) model of photosynthesis. These models were coupled to each other and a leaf energy balance model in order to predict in situ leaf CO2 and water fluxes which were compared against field measurements. There was significant physiological plasticity and genetic variation in the sensitivity of stomatal conductance to A, RH and [CO2]. This was reflected in significant variation in parameters of the Ball et al. (1987) model, with the key slope parameter (m) ranging from more than 4-fold. Context-specific parameterization of this widely used stomatal conductance model reduced error in predictions of in situ leaf A and gs by up to 59

  16. Predicting significant torso trauma. (United States)

    Nirula, Ram; Talmor, Daniel; Brasel, Karen


    Identification of motor vehicle crash (MVC) characteristics associated with thoracoabdominal injury would advance the development of automatic crash notification systems (ACNS) by improving triage and response times. Our objective was to determine the relationships between MVC characteristics and thoracoabdominal trauma to develop a torso injury probability model. Drivers involved in crashes from 1993 to 2001 within the National Automotive Sampling System were reviewed. Relationships between torso injury and MVC characteristics were assessed using multivariate logistic regression. Receiver operating characteristic curves were used to compare the model to current ACNS models. There were a total of 56,466 drivers. Age, ejection, braking, avoidance, velocity, restraints, passenger-side impact, rollover, and vehicle weight and type were associated with injury (p < 0.05). The area under the receiver operating characteristic curve (83.9) was significantly greater than current ACNS models. We have developed a thoracoabdominal injury probability model that may improve patient triage when used with ACNS.

  17. Aerobic respiration along isopycnals leads to overestimation of the isotope effect of denitrification in the ocean water column (United States)

    Marconi, Dario; Kopf, Sebastian; Rafter, Patrick A.; Sigman, Daniel M.


    The nitrogen (N) isotopes provide an integrative geochemical tool for constraining the fixed N budget of the ocean. However, N isotope budgeting requires a robust estimate for the organism-scale nitrogen isotope effect of denitrification, in particular as it occurs in water column denitrification zones (εwcd). Ocean field data interpreted with the Rayleigh model have typically yielded estimates for εwcd of between 20 and 30‰. However, recent findings have raised questions about this value. In particular, culture experiments can produce a substantially lower isotope effect (∼13‰) under conditions mimicking those of ocean suboxic zones. In an effort to better understand prior field estimates of εwcd, we use a geochemical multi-box model to investigate the combined effects of denitrification, aerobic respiration, and isopycnal exchange on the δ15N of nitrate. In the context of this admittedly simplistic model, we consider three isopycnals extending from the Southern Ocean to the Eastern Tropical North Pacific (ETNP). We show that the data from the ETNP suboxic zone can be reproduced with an εwcd of 13‰, given a rate of aerobic respiration consistent with the nutrient data on these isopycnals and a plausible range in the δ15N of the sinking flux being remineralized. We discuss the limitations of our analysis, additional considerations, as well as possible data-based tests for the proposal of a lower εwcd than previously estimated. All else held constant, a lower εwcd would imply a lower global ocean rate of denitrification that is more similar to the estimated rate of N input to the global ocean, providing a major impetus for further investigation.

  18. Modeling, Analysis, and Control of a Hypersonic Vehicle with Significant Aero-Thermo-Elastic-Propulsion Interactions: Elastic, Thermal and Mass Uncertainty (United States)

    Khatri, Jaidev

    This thesis examines themodeling, analysis, and control system design issues for scramjet powered hypersonic vehicles. A nonlinear three degrees of freedom longitudinal model which includes aero-propulsion-elasticity effects was used for all analyses. This model is based upon classical compressible flow and Euler-Bernouli structural concepts. Higher fidelity computational fluid dynamics and finite element methods are needed for more precise intermediate and final evaluations. The methods presented within this thesis were shown to be useful for guiding initial control relevant design. The model was used to examine the vehicle's static and dynamic characteristics over the vehicle's trimmable region. The vehicle has significant longitudinal coupling between the fuel equivalency ratio (FER) and the flight path angle (FPA). For control system design, a two-input two-output plant (FER - elevator to speed-FPA) with 11 states (including 3 flexible modes) was used. Velocity, FPA, and pitch were assumed to be available for feedback. Aerodynamic heat modeling and design for the assumed TPS was incorporated to original Bolender's model to study the change in static and dynamic properties. De-centralized control stability, feasibility and limitations issues were dealt with the change in TPS elasticity, mass and physical dimension. The impact of elasticity due to TPS mass, TPS physical dimension as well as prolonged heating was also analyzed to understand performance limitations of de-centralized control designed for nominal model.

  19. The significance of the interception in a Thornthwaite-type monthly step water balance model in context of the climate change (United States)

    Herceg, András; Kalicz, Péter; Kisfaludi, Balázs


    The hydrological impacts of the climate change can be dramatic. Our main purpose is the methodical improvement of a previously established Thornthwaite-type monthly step water balance model, which takes the interception item into account, and compare the results of the evapotranspiration and the soil moisture projections for the 21st century of the original and the upgraded models. Both of the models will be calibrated and validated (using remote-sensed actual evapotranspiration data, called CREMAP) and requires only temperature and precipitation time series as inputs. The projections based on 4 bias-corrected regional climate models databases (FORESEE), and the 3 investigation periods are: 2015-2045, 2045-2075, and 2070-2100. The key parameter is the water storage capacity of the soil, which can be also calibrated using the actual evapotranspiration data. The maximal rooting depth is determinable if the physical properties of the soil are available. The interception can be ranges from 5-40% of gross precipitation, which rate are differing in the various plant communities. Generally, the forests canopy intercepts considerable amounts of rainfall and evaporates back into the atmosphere during and after precipitation event. Leaf area index (LAI) is one of the most significant factor, which determine the canopies storage capacity. Here, MODIS sensor based LAI time series are applied to estimate the storage capacity. A forest covered experimental catchment is utilized for testing the models near to Sopron, Hungary. The projections will expected to demonstrate increasing actual evapotranspiration values, but decreasing trends for the 10 percentile minimum soil moisture values at the end of the 21st century in both model runs. The seasonal periodicity of evapotranspiration may demonstrates the maximums in June or July, while in case of the soil moisture it may shows minimum values in autumn. With the comparison of the two model runs, we expect lower soil water storage

  20. Future of Grid-Tied PV Business Models: What Will Happen When PV Penetration on the Distribution Grid is Significant? Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Graham, S.; Katofsky, R.; Frantzis, L.; Sawyer, H.; Margolis, R.


    Eventually, distributed PV will become a more significant part of the generation mix. When this happens, it is expected that utilities will have to take on a more active role in the placement, operation and control of these systems. There are operational complexities and concerns of revenue erosion that will drive utilities into greater involvement of distributed PV and will create new business models. This report summarizes work done by Navigant Consulting Inc. for the National Renewable Energy Laboratory as part of the Department of Energy's work on Renewable System Integration. The objective of the work was to better understand the structure of these future business models and the research, development and demonstration (RD&D) required to support their deployment. This report describes potential future PV business models in terms of combinations of utility ownership and control of the PV assets, and the various relationships between end-users and third-party owners.

  1. Incorporating biologic measurements (SF(2), CFE) into a tumor control probability model increases their prognostic significance: a study in cervical carcinoma treated with radiation therapy. (United States)

    Buffa, F M; Davidson, S E; Hunter, R D; Nahum, A E; West, C M


    To assess whether incorporation of measurements of surviving fraction at 2 Gy (SF(2)) and colony-forming efficiency (CFE) into a tumor control probability (tcp) model increases their prognostic significance. Measurements of SF(2) and CFE were available from a study on carcinoma of the cervix treated with radiation alone. These measurements, as well as tumor volume, dose, and treatment time, were incorporated into a Poisson tcp model (tcp(alpha,rho)). Regression analysis was performed to assess the prognostic power of tcp(alpha,rho) vs. the use of either tcp models with biologic parameters fixed to best-fit estimates (but incorporating individual dose, volume, and treatment time) or the use of SF(2) and CFE measurements alone. In a univariate regression analysis of 44 patients, tcp(alpha,rho) was a better prognostic factor for both local control and survival (p CFE alone (p = 0.015 for local control, p = 0.38 for survival). In multivariate analysis, tcp(alpha,rho) emerged as the most important prognostic factor for local control (p CFE was still a significant independent prognostic factor for local control, whereas SF(2) was not. The sensitivities of tcp(alpha,rho) and SF(2) as predictive tests for local control were 87% and 65%, respectively. Specificities were 70% and 77%, respectively. A Poisson tcp model incorporating individual SF(2), CFE, dose, tumor volume, and treatment time was found to be the best independent prognostic factor for local control and survival in cervical carcinoma patients.

  2. Overestimation of heterosexually attributed AIDS deaths is associated with immature psychological defence mechanisms and clitoral masturbation during penile-vaginal intercourse. (United States)

    Brody, S; Costa, R M


    Research shows that (1) greater use of immature psychological defence mechanisms (associated with psychopathology) is associated with lesser orgasmic consistency from penile-vaginal intercourse (PVI), but greater frequency of other sexual behaviours and greater condom use for PVI, and (2) unlike the vectors of receptive anal intercourse and punctures, HIV acquisition during PVI is extremely unlikely in reasonably healthy persons. However, the relationship between overestimation of AIDS deaths due to 'heterosexual transmission' (often misunderstood as only PVI), sexual behaviour and mental health has been lacking. Two hundred and twenty-one Scottish women completed the Defense Style Questionnaire, reported past month frequencies of their various sexual activities, and estimated the total number of women who died from AIDS in Scotland nominally as a result of heterosexual transmission in the UK from a partner not known to be an injecting drug user, bisexual or infected through transfusion. The average respondent overestimated by 226,000%. Women providing lower estimates were less likely to use immature psychological defences, and had a lower frequency of orgasms from clitoral masturbation during PVI and from vibrator use. The results indicate that those who perceive 'heterosexual transmission' led to many AIDS deaths have poorer psychological functioning, and might be less able to appreciate PVI.

  3. Male-biased mutation rates and the overestimation of extrapair paternity: problem, solution, and illustration using thick-billed murres (Uria lomvia, Alcidae). (United States)

    Ibarguchi, G; Gissing, G J; Gaston, A J; Boag, P T; Friesen, V L


    The widespread utility of hypervariable loci in genetic studies derives from the high mutation rate, and thus the high polymorphism, of these loci. Recent evidence suggests that mutation rates can be extremely high and may be male biased (occurring in the male germ-line). These two factors combined may result in erroneous overestimates of extrapair paternity, since legitimate offspring with novel alleles will have more mismatches with respect to the biological father than the biological mother. As mutations are male driven, increasing the number of hypervariable loci screened may simply increase the number of mismatches between fathers and their legitimate offspring. Here we describe a simple statistic, the probability of resemblance (PR), to distinguish between mismatches due to parental misassignment versus mutation in either sex or null alleles. We apply this method to parentage data on thick-billed murres (Uria lomvia), and demonstrate that, without considering either mutations or male-biased mutation rates, cases of extrapair paternity (7% in this study) would be grossly overestimated (14.5%-22%). The probability of resemblance can be utilized in parentage studies of any sexually reproducing species when allele or haplotype frequency data are available for putative parents and offspring. We suggest calculating this probability to correctly categorize legitimate offspring when mutations and null alleles may cause mismatches.

  4. Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season (United States)

    Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard


    Maize is the most important C4 crop worldwide. It is also the second most important crop worldwide (C3 and C4 mixed), and is a dominant crop in some world regions. Therefore, it can potentially influence local climate and air quality through its exchanges of gases with the atmosphere. Among others, biogenic volatile organic compounds (BVOC) are known to influence the atmospheric composition and thereby modify greenhouse gases lifetime and pollutant formation in the atmosphere. However, so far, only two studies have dealt with BVOC exchanges from maize. Moreover, these studies were conducted on a limited range of meteorological and phenological conditions, so that the knowledge of BVOC exchanges by this crop remains poor. Here, we present the first BVOC measurement campaign performed at ecosystem-scale on a maize field during a whole growing season. It was carried out in the Lonzée Terrestrial Observatory (LTO), an ICOS site. BVOC fluxes were measured by the disjunct by mass-scanning eddy covariance technique with a proton transfer reaction mass spectrometer for BVOC mixing ratios measurements. Outstanding results are (i) BVOC exchanges from soil were as important as BVOC exchanges from maize itself; (ii) BVOC exchanges observed on our site were much lower than exchanges observed by other maize studies, even under normalized temperature and light conditions, (iii) they were also lower than those observed on other crops grown in Europe. Lastly (iv), BVOC exchanges observed on our site under standard environmental conditions, i.e., standard emission factors SEF, were much lower than those currently considered by BVOC exchange up-scaling models. From those observations, we deduced that (i) soil BVOC exchanges should be better understood and should be incorporated in terrestrial BVOC exchanges models, and that (ii) SEF for the C4 crop plant functional type cannot be evaluated at global scale but should be determined for each important agronomic and pedo-climatic region

  5. Surface tensions of multi-component mixed inorganic/organic aqueous systems of atmospheric significance: measurements, model predictions and importance for cloud activation predictions

    Directory of Open Access Journals (Sweden)

    D. O. Topping


    Full Text Available In order to predict the physical properties of aerosol particles, it is necessary to adequately capture the behaviour of the ubiquitous complex organic components. One of the key properties which may affect this behaviour is the contribution of the organic components to the surface tension of aqueous particles in the moist atmosphere. Whilst the qualitative effect of organic compounds on solution surface tensions has been widely reported, our quantitative understanding on mixed organic and mixed inorganic/organic systems is limited.  Furthermore, it is unclear whether models that exist in the literature can reproduce the surface tension variability for binary and higher order multi-component organic and mixed inorganic/organic systems of atmospheric significance. The current study aims to resolve both issues to some extent. Surface tensions of single and multiple solute aqueous solutions were measured and compared with predictions from a number of model treatments. On comparison with binary organic systems, two predictive models found in the literature provided a range of values resulting from sensitivity to calculations of pure component surface tensions.  Results indicate that a fitted model can capture the variability of the measured data very well, producing the lowest average percentage deviation for all compounds studied.  The performance of the other models varies with compound and choice of model parameters. The behaviour of ternary mixed inorganic/organic systems was unreliably captured by using a predictive scheme and this was composition dependent. For more "realistic" higher order systems, entirely predictive schemes performed poorly. It was found that use of the binary data in a relatively simple mixing rule, or modification of an existing thermodynamic model with parameters derived from binary data, was able to accurately capture the surface tension variation with concentration. Thus, it would appear that in order to model

  6. Are emissions of black carbon from gasoline vehicles overestimated? Real-time, in situ measurement of black carbon emission factors. (United States)

    Wang, Yang; Xing, Zhenyu; Zhao, Shuhui; Zheng, Mei; Mu, Chao; Du, Ke


    Accurately quantifying black carbon (BC) emission factors (EFs) is a prerequisite for estimation of BC emission inventory. BC EFs determined by measuring BC at the roadside or chasing a vehicle on-road may introduce large uncertainty for low emission vehicles. In this study, BC concentrations were measured inside the tailpipe of gasoline vehicles with different engine sizes under different driving modes to determine the respective EFs. BC EFs ranged from 0.005-7.14 mg/kg-fuel under the speeds of 20-70 km/h, 0.05-28.95 mg/kg-fuel under the accelerations of 0.5-1.5m/s(2). Although the water vapor in the sampling stream could result in an average of 12% negative bias, the BC EFs are significantly lower than the published results obtained with roadside or chasing vehicle measurement. It is suggested to conduct measurement at the tailpipe of gasoline vehicles instead of in the atmosphere behind the vehicles to reduce the uncertainty from fluctuation in ambient BC concentration. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Could the coefficient of variation (COV) of the corneal endothelium be overestimated when a centre-dot method is used? (United States)

    Doughty, Michael J


    Little has been published on the reliability of estimates of the coefficient of variation (COV) in cell area for human corneal endothelia. The present study compares two methods. A non-contact specular micrograph (Topcon SP-2000P) was obtained from the central region of the corneal endothelium of 20 healthy myopic white European subjects, aged from 32 to 53 years, half of whom were successful long-term soft contact lens wearers. The captured image file was either assessed using a machine-based algorithm, in which 25 cells in the middle of the image were marked and their areas reported (designated as 'centre-dot' method) or by a manual method, by which all the cells in the image were outlined on very high magnification prints of the endothelia and the cell areas measured by a manual digitiser in stream mode. The average cell area was used to calculate the endothelial cell density (ECD), while the COV was calculated from the standard deviation (SD) of the cell area measures. Identical mean cell area values were found (392 microm(2)) with the two methods, a marginally higher ECD estimate (2,594 versus 2,569) with the centre-dot method (p = NS) but a much higher COV with the centre-dot method (43.8 versus 29.0 per cent). This highly statistically significant difference in COV (p definition of a single large cell domain on any individual image. A centre-dot method can be reliably used to generate useful data on cell area and ECD but it should be used cautiously for estimates of polymegethism (COV).

  8. Estimation of torque on mechanical heart valves due to magnetic resonance imaging including an estimation of the significance of the Lenz effect using a computational model

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Neil M. [44 Ardgowan Street, Greenock PA16 8EL (United Kingdom). E-mail: neil.robertson at; Diaz-Gomez, Manuel [Plaza Alcalde Horacio Hermoso, 2, 3-A 41013 Seville (Spain). E-mail: manolo-diaz at; Condon, Barrie [Department of Clinical Physics, Institute of Neurological Sciences, Glasgow G51 4TF (United Kingdom). E-mail: barrie.condon at


    Mitral and aortic valve replacement is a procedure which is common in cardiac surgery. Some of these replacement valves are mechanical and contain moving metal parts. Should the patient in whom such a valve has been implanted be involved in magnetic resonance imaging, there is a possible dangerous interaction between the moving metal parts and the static magnetic field due to the Lenz effect. Mathematical models of two relatively common forms of single-leaflet valves have been derived and the magnitude of the torque which opposes the motion of the valve leaflet has been calculated for a valve disc of solid metal. In addition, a differential model of a ring-strengthener valve type has been considered to determine the likely significance of the Lenz effect in the context of the human heart. For common magnetic field strengths at present, i.e. 1 to 2 T, the effect is not particularly significant. However, there is a marked increase in back pressure as static magnetic field strength increases. There are concerns that, since field strengths in the range 3 to 4 T are increasingly being used, the Lenz effect could become significant. At 5 to 10 T the malfunction of the mechanical heart valve could cause the heart to behave as though it is diseased. For unhealthy or old patients this could possibly prove fatal. (author)

  9. Significance of spatial variability in precipitation for process-oriented modelling: results from two nested catchments using radar and ground station data

    Directory of Open Access Journals (Sweden)

    D. Tetzlaff


    Full Text Available The importance of considering the spatial distribution of rainfall for process-oriented hydrological modelling is well-known. However, the application of rainfall radar data to provide such detailed spatial resolution is still under debate. In this study the process-oriented TACD (Tracer Aided Catchment model, Distributed model had been used to investigate the effects of different spatially distributed rainfall input on simulated discharge and runoff components on an event base. TACD is fully distributed (50x50m2 raster cells and was applied on an hourly base. As model input rainfall data from up to 7 ground stations and high resolution rainfall radar data from operational C-band radar were used. For seven rainfall events the discharge simulations were investigated in further detail for the mountainous Brugga catchment (40km2 and the St. Wilhelmer Talbach (15.2km2 sub-basin, which are located in the Southern Black Forest Mountains, south-west Germany. The significance of spatial variable precipitation data was clearly demonstrated. Dependent on event characteristics, localized rain cells were occasionally poorly captured even by a dense ground station network, and this resulted in inadequate model results. For such events, radar data can provide better input data. However, an extensive data adjustment using ground station data is required. For this purpose a method was developed that considers the temporal variability in rainfall intensity in high temporal resolution in combination with the total rainfall amount of both data sets. The use of the distributed catchment model allowed further insights into spatially variable impacts of different rainfall estimates. Impacts for discharge predictions are the largest in areas that are dominated by the production of fast runoff components. The improvements for distributed runoff simulation using high resolution rainfall radar input data are strongly dependent on the investigated scale, the event

  10. Expression and significance of IL-1β and COX-2 in gingiva tissues in rat periodontitis model with different estrogen levels

    Institute of Scientific and Technical Information of China (English)

    Li-Bo Ku; Guo-Quan Xu; Hui Wang; Zhi-Hua Zhao; Shi-Yu Ding; Li Ma


    Objective:To explore the expressions of IL-1β and COX-2 in the gingiva tissues in rat periodontitis model with different estrogen levels, and the effect of estrogen level on periodontitis.Methods:A total of 40 female Wistar rats were randomized into 4 groups, i.e. normal control group (n=10), periodontitis group (n=10), castraction periodontitis group (n=10), and estrogen therapy group (n=10). RT-PCR was used to detect the expressions of IL-1β and COX-2 in the gingiva tissues in each group.Results:The expression intensity of IL-1β and COX-2 in the estrogen therapy group was significantly lower than that in the castraction periodontitis group (P<0.05).Conclusions:Estrogen can significantly down regulate the expressions of IL-1β and COX-2 in order to alleviate the symptoms of periodontitis.

  11. Surface tensions of multi-component mixed inorganic/organic aqueous systems of atmospheric significance: measurements, model predictions and importance for cloud activation predictions

    Directory of Open Access Journals (Sweden)

    D. O. Topping


    Full Text Available In order to predict the physical properties of aerosol particles, it is necessary to adequately capture the behaviour of the ubiquitous complex organic components. One of the key properties which may affect this behaviour is the contribution of the organic components to the surface tension of aqueous particles in the moist atmosphere. Whilst the qualitative effect of organic compounds on solution surface tensions has been widely reported, our quantitative understanding on mixed organic and mixed inorganic/organic systems is limited. Furthermore, it is unclear whether models that exist in the literature can reproduce the surface tension variability for binary and higher order multi-component organic and mixed inorganic/organic systems of atmospheric significance. The current study aims to resolve both issues to some extent. Surface tensions of single and multiple solute aqueous solutions were measured and compared with predictions from a number of model treatments. On comparison with binary organic systems, two predictive models found in the literature provided a range of values resulting from sensitivity to calculations of pure component surface tensions. Results indicate that a fitted model can capture the variability of the measured data very well, producing the lowest average percentage deviation for all compounds studied. The performance of the other models varies with compound and choice of model parameters. The behaviour of ternary mixed inorganic/organic systems was unreliably captured by using a predictive scheme and this was dependent on the composition of the solutes present. For more atmospherically representative higher order systems, entirely predictive schemes performed poorly. It was found that use of the binary data in a relatively simple mixing rule, or modification of an existing thermodynamic model with parameters derived from binary data, was able to accurately capture the surface tension variation with concentration. Thus

  12. Significant blockade of multiple receptor tyrosine kinases by MGCD516 (Sitravatinib), a novel small molecule inhibitor, shows potent anti-tumor activity in preclinical models of sarcoma. (United States)

    Patwardhan, Parag P; Ivy, Kathryn S; Musi, Elgilda; de Stanchina, Elisa; Schwartz, Gary K


    Sarcomas are rare but highly aggressive mesenchymal tumors with a median survival of 10-18 months for metastatic disease. Mutation and/or overexpression of many receptor tyrosine kinases (RTKs) including c-Met, PDGFR, c-Kit and IGF1-R drive defective signaling pathways in sarcomas. MGCD516 (Sitravatinib) is a novel small molecule inhibitor targeting multiple RTKs involved in driving sarcoma cell growth. In the present study, we evaluated the efficacy of MGCD516 both in vitro and in mouse xenograft models in vivo. MGCD516 treatment resulted in significant blockade of phosphorylation of potential driver RTKs and induced potent anti-proliferative effects in vitro. Furthermore, MGCD516 treatment of tumor xenografts in vivo resulted in significant suppression of tumor growth. Efficacy of MGCD516 was superior to imatinib and crizotinib, two other well-studied multi-kinase inhibitors with overlapping target specificities, both in vitro and in vivo. This is the first report describing MGCD516 as a potent multi-kinase inhibitor in different models of sarcoma, superior to imatinib and crizotinib. Results from this study showing blockade of multiple driver signaling pathways provides a rationale for further clinical development of MGCD516 for the treatment of patients with soft-tissue sarcoma.

  13. Quantitative renal perfusion measurements in a rat model of acute kidney injury at 3T: testing inter- and intramethodical significance of ASL and DCE-MRI.

    Directory of Open Access Journals (Sweden)

    Fabian Zimmer

    Full Text Available OBJECTIVES: To establish arterial spin labelling (ASL for quantitative renal perfusion measurements in a rat model at 3 Tesla and to test the diagnostic significance of ASL and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI in a model of acute kidney injury (AKI. MATERIAL AND METHODS: ASL and DCE-MRI were consecutively employed on six Lewis rats, five of which had a unilateral ischaemic AKI. All measurements in this study were performed on a 3 Tesla MR scanner using a FAIR True-FISP approach and a TWIST sequence for ASL and DCE-MRI, respectively. Perfusion maps were calculated for both methods and the cortical perfusion of healthy and diseased kidneys was inter- and intramethodically compared using a region-of-interest based analysis. RESULTS/SIGNIFICANCE: Both methods produce significantly different values for the healthy and the diseased kidneys (P<0.01. The mean difference was 147±47 ml/100 g/min and 141±46 ml/100 g/min for ASL and DCE-MRI, respectively. ASL measurements yielded a mean cortical perfusion of 416±124 ml/100 g/min for the healthy and 316±102 ml/100 g/min for the diseased kidneys. The DCE-MRI values were systematically higher and the mean cortical renal blood flow (RBF was found to be 542±85 ml/100 g/min (healthy and 407±119 ml/100 g/min (AKI. CONCLUSION: Both methods are equally able to detect abnormal perfusion in diseased (AKI kidneys. This shows that ASL is a capable alternative to DCE-MRI regarding the detection of abnormal renal blood flow. Regarding absolute perfusion values, nontrivial differences and variations remain when comparing the two methods.

  14. Evaluation of a lake whitefish bioenergetics model (United States)

    Madenjian, Charles P.; O'Connor, Daniel V.; Pothoven, Steven A.; Schneeberger, Philip J.; Rediske, Richard R.; O'Keefe, James P.; Bergstedt, Roger A.; Argyle, Ray L.; Brandt, Stephen B.


    We evaluated the Wisconsin bioenergetics model for lake whitefish Coregonus clupeaformis in the laboratory and in the field. For the laboratory evaluation, lake whitefish were fed rainbow smelt Osmerus mordax in four laboratory tanks during a 133-d experiment. Based on a comparison of bioenergetics model predictions of lake whitefish food consumption and growth with observed consumption and growth, we concluded that the bioenergetics model furnished significantly biased estimates of both food consumption and growth. On average, the model overestimated consumption by 61% and underestimated growth by 16%. The source of the bias was probably an overestimation of the respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit of the model to the observed consumption and growth in our laboratory tanks. Based on the adjusted model, predictions of food consumption over the 133-d period fell within 5% of observed consumption in three of the four tanks and within 9% of observed consumption in the remaining tank. We used polychlorinated biphenyls (PCBs) as a tracer to evaluate model performance in the field. Based on our laboratory experiment, the efficiency with which lake whitefish retained PCBs from their food (I?) was estimated at 0.45. We applied the bioenergetics model to Lake Michigan lake whitefish and then used PCB determinations of both lake whitefish and their prey from Lake Michigan to estimate p in the field. Application of the original model to Lake Michigan lake whitefish yielded a field estimate of 0.28, implying that the original formulation of the model overestimated consumption in Lake Michigan by 61%. Application of the bioenergetics model with the adjusted respiration component resulted in a field I? estimate of 0.56, implying that this revised model underestimated consumption by 20%.

  15. Paleomagnetic data support Early Permian age for the Abor Volcanics in the lower Siang Valley, NE India: Significance for Gondwana-related break-up models (United States)

    Ali, Jason R.; Aitchison, Jonathan C.; Chik, Sam Y. S.; Baxter, Alan T.; Bryan, Scott E.


    Confusion exists as to the age of the Abor Volcanics of NE India. Some consider the unit to have been emplaced in the Early Permian, others the Early Eocene, a difference of ˜230 million years. The divergence in opinion is significant because fundamentally different models explaining the geotectonic evolution of India depend on the age designation of the unit. Paleomagnetic data reported here from several exposures in the type locality of the formation in the lower Siang Valley indicate that steep dipping primary magnetizations (mean = 72.7 ± 6.2°, equating to a paleo-latitude of 58.1°) are recorded in the formation. These are only consistent with the unit being of Permian age, possibly Artinskian based on a magnetostratigraphic argument. Plate tectonic models for this time consistently show the NE corner of the sub-continent >50°S; in the Early Eocene it was just north of the equator, which would have resulted in the unit recording shallow directions. The mean declination is counter-clockwise rotated by ˜94°, around half of which can be related to the motion of the Indian block; the remainder is likely due local Himalayan-age thrusting in the Eastern Syntaxis. Several workers have correlated the Abor Volcanics with broadly coeval mafic volcanic suites in Oman, NE Pakistan-NW India and southern Tibet-Nepal, which developed in response to the Cimmerian block peeling-off eastern Gondwana in the Early-Middle Permian, but we believe there are problems with this model. Instead, we suggest that the Abor basalts relate to India-Antarctica/India-Australia extension that was happening at about the same time. Such an explanation best accommodates the relevant stratigraphical and structural data (present-day position within the Himalayan thrust stack), as well as the plate tectonic model for Permian eastern Gondwana.

  16. Novel Anti-Adhesive CMC-PE Hydrogel Significantly Enhanced Morphological and Physiological Recovery after Surgical Decompression in an Animal Model of Entrapment Neuropathy (United States)

    Urano, Hideki; Iwatsuki, Katsuyuki; Yamamoto, Michiro; Ohnisi, Tetsuro; Kurimoto, Shigeru; Endo, Nobuyuki; Hirata, Hitoshi


    We developed a novel hydrogel derived from sodium carboxymethylcellulose (CMC) in which phosphatidylethanolamine (PE) was introduced into the carboxyl groups of CMC to prevent perineural adhesions. This hydrogel has previously shown excellent anti-adhesive effects even after aggressive internal neurolysis in a rat model. Here, we confirmed the effects of the hydrogel on morphological and physiological recovery after nerve decompression. We prepared a rat model of chronic sciatic nerve compression using silicone tubing. Morphological and physiological recovery was confirmed at one, two, and three months after nerve decompression by assessing motor conduction velocity (MCV), the wet weight of the tibialis anterior muscle and morphometric evaluations of nerves. Electrophysiology showed significantly quicker recovery in the CMC-PE group than in the control group (24.0 ± 3.1 vs. 21.0± 2.1 m/s (p < 0.05) at one months and MCV continued to be significantly faster thereafter. Wet muscle weight at one month significantly differed between the CMC-PE (BW) and control groups (0.148 ± 0.020 vs. 0.108 ± 0.019%BW). The mean wet muscle weight was constantly higher in the CMC-PE group than in the control group throughout the experimental period. The axon area at one month was twice as large in the CMC-PE group compared with the control group (24.1 ± 17.3 vs. 12.3 ± 9 μm2) due to the higher ratio of axons with a larger diameter. Although the trend continued throughout the experimental period, the difference decreased after two months and was not statistically significant at three months. Although anti-adhesives can reduce adhesion after nerve injury, their effects on morphological and physiological recovery after surgical decompression of chronic entrapment neuropathy have not been investigated in detail. The present study showed that the new anti-adhesive CMC-PE gel can accelerate morphological and physiological recovery of nerves after decompression surgery. PMID:27741280

  17. The dimensions and role of commensality: A theoretical model drawn from the significance of communal eating among adults in Santiago, Chile. (United States)

    Giacoman, Claudia


    This article examines the significance of communal eating among adults from Santiago, Chile, by elaborating on a theoretical model for commensality that is based on empirical material. Based on this objective, 24 group interviews were conducted in Santiago with family members, coworkers, and friends who shared meals with one another. The results showed that the practice of commensality strengthens the cohesion among the members of a group, providing an interactive space in which communal belonging is symbolized and shared norms are respected. However, eating together also is assigned an ambiguous value: On the one hand, commensality is viewed as positive in enabling connections with others. On the other hand, participating in commensality can be viewed as negative, causing tensions depending on the characteristics of the commensal group and the context.


    Directory of Open Access Journals (Sweden)

    Mariana C. JUGANARU


    Full Text Available For the Romanian economy, Constanța is appreciated mainly because it is the biggest port town in the country, and for many generations it has been the city where they spend many of their summer holidays. But how many of us know that the bathroom resort – Constanța has an officially attested existence of 140 years? In this study, the aim is, on one side, to present the significant moments in the history and evolution of this historic city, in order to bring to the foreground and sustain the position that the city has at the present moment in the system of touristic spots on the Romanian seaside, and on the other side, our concern is to know the future evolution of the touristic activity, to make some previsions using the ARIMA models, for one of the most used indicators in the analysis of touristic circulation, respectively: the number of arrivals of tourists, structurally and totally: Romanian and foreigners. We think that the obtained results, applying these models, may be considered a solid base for different debates regarding the choice of an efficient strategy, that should allow reaching an equilibrium between the effort of attracting a number of tourists as big as possible (Romanian and foreigners, of growing their degree of satisfaction towards the touristic offer and the concern of not generating disruptions in the economic, social and cultural life of the city.

  19. Motavizumab, A Neutralizing Anti-Respiratory Syncytial Virus (Rsv Monoclonal Antibody Significantly Modifies The Local And Systemic Cytokine Responses Induced By Rsv In The Mouse Model

    Directory of Open Access Journals (Sweden)

    Jafri Hasan S


    Full Text Available Abstract Motavizumab (MEDI-524 is a monoclonal antibody with enhanced neutralizing activity against RSV. In mice, motavizumab suppressed RSV replication which resulted in significant reduction of clinical parameters of disease severity. We evaluated the effect of motavizumab on the local and systemic immune response induced by RSV in the mouse model. Balb/c mice were intranasally inoculated with 106.5 PFU RSV A2 or medium. Motavizumab was given once intraperitoneally (1.25 mg/mouse as prophylaxis, 24 h before virus inoculation. Bronchoalveolar lavage (BAL and serum samples were obtained at days 1, 5 (acute and 28 (long-term post inoculation and analyzed with a multiplex assay (Beadlyte Upstate, NY for simultaneous quantitation of 18 cytokines: IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, KC (similar to human IL-8, IL-10, IL-12p40, IL-12p70, IL-13, IL-17, TNF-α, MCP-1, RANTES, IFN-γ and GM-CSF. Overall, cytokine concentrations were lower in serum than in BAL samples. By day 28, only KC was detected in BAL specimens at low concentrations in all groups. Administration of motavizumab significantly reduced (p

  20. Significant RF-EMF and thermal levels observed in a computational model of a person with a tibial plate for grounded 40 MHz exposure. (United States)

    McIntosh, Robert L; Iskra, Steve; Anderson, Vitas


    Using numerical modeling, a worst-case scenario is considered when a person with a metallic implant is exposed to a radiofrequency (RF) electromagnetic field (EMF). An adult male standing on a conductive ground plane was exposed to a 40 MHz vertically polarized plane wave field, close to whole-body resonance where maximal induced current flows are expected in the legs. A metal plate (50-300 mm long) was attached to the tibia in the left leg. The findings from this study re-emphasize the need to ensure compliance with limb current reference levels for exposures near whole-body resonance, and not just rely on compliance with ambient electric (E) and magnetic (H) field reference levels. Moreover, we emphasize this recommendation for someone with a tibial plate, as failure to comply may result in significant tissue damage (increases in the localized temperature of 5-10 °C were suggested by the modeling for an incident E-field of 61.4 V/m root mean square (rms)). It was determined that the occupational reference level for limb current (100 mA rms), as stipulated in the 1998 guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), is satisfied if the plane wave incident E-field levels are no more than 29.8 V/m rms without an implant and 23.4 V/m rms for the model with a 300 mm implant.

  1. A dual acting compound releasing nitric oxide (NO) and ibuprofen, NCX 320, shows significant therapeutic effects in a mouse model of muscular dystrophy. (United States)

    Sciorati, Clara; Miglietta, Daniela; Buono, Roberta; Pisa, Viviana; Cattaneo, Dario; Azzoni, Emanuele; Brunelli, Silvia; Clementi, Emilio


    A resolutive therapy for muscular dystrophies, a heterogeneous group of genetic diseases leading to muscular degeneration and in the severe forms to death, is still lacking. Since inflammation and defects in nitric oxide generation are recognized key pathogenic events in muscular dystrophy, we have analysed the effects of a derivative of ibuprofen, NCX 320, belonging to the class of cyclooxygenase inhibiting nitric oxide donator (CINOD), in the α-sarcoglycan null mice, a severe mouse model of dystrophy. NCX 320 was administered daily in the diet for 8months starting 1month from weaning. Muscle functional recovery was evaluated by free wheel and treadmill tests at 8months. Serum creatine kinase activity, as well as the number of diaphragm inflammatory infiltrates and necrotic fibres, was measured as indexes of skeletal muscle damage. Muscle regeneration was evaluated in diaphragm and tibialis anterior muscles, measuring the numbers of centronucleated fibres and of myogenic precursor cells. NCX 320 mitigated muscle damage, reducing significantly serum creatine kinase activity, the number of necrotic fibres and inflammatory infiltrates. Moreover, NCX 320 stimulated muscle regeneration increasing significantly the number of myogenic precursor cells and regenerating fibres. All these effects concurred in inducing a significant improvement of muscle function, as assessed by both free wheel and treadmill tests. These results describe the properties of a new compound incorporating nitric oxide donation together with anti-inflammatory properties, showing that it is effective in slowing muscle dystrophy progression long term. Of importance, this new compound deserves specific attention for its potential in the therapy of muscular dystrophy given that ibuprofen is well tolerated in paediatric patients and with a profile of safety that makes it suitable for chronic treatment such as the one required in muscular dystrophies.


    Energy Technology Data Exchange (ETDEWEB)

    Noam Lior; Stuart W. Churchill


    The primary objective of the proposed study was the study and analysis of, and design recommendations for, a novel radiatively-conductively stabilized combustion (RCSC) process for pulverized coal, which, based on our prior studies with both fluid fuels and pulverized coal, holds a high promise to reduce NO{sub x} production significantly. We have primarily engaged in continuing and improving our process modeling and analysis, obtained a large amount of quantitative information about the effects of the major parameters on NO{sub x} production, conducted an extensive exergy analysis of the process, evaluated the practicalities of employing the Radiatively-Conductively Stabilized Combustor (RCSC) to large power and heat plants, and improved the experimental facility. Prior experimental work has proven the feasibility of the combustor, but slagging during coal combustion was observed and should be dealt with. The primary outcomes and conclusions from the study are: (1) we developed a model and computer program that represents the pulverized coal combustion in the RCSC, (2) the model predicts that NO{sub x} emissions can be reduced by a number of methods, detailed in the report. (3) the exergy analysis points out at least a couple of possible ways to improve the exergetic efficiency in this combustor: increasing the effectiveness of thermal feedback, and adjusting the combustor mixture exit location, (4) because of the low coal flow rates necessitated in this study to obtain complete combustion in the burner, the size of a burner operating under the considered conditions would have to be up to an order of magnitude, larger than comparable commercial burners, but different flow configurations of the RCSC can yield higher feed rates and smaller dimensions, and should be investigated. Related to this contract, eleven papers were published in journals and conference proceedings, and ten invited presentations were given at university and research institutions, as well as at

  3. Evaluation and application of site-specific data to revise the first-order decay model for estimating landfill gas generation and emissions at Danish landfills

    DEFF Research Database (Denmark)

    Mou, Zishen; Scheutz, Charlotte; Kjeldsen, Peter


    Methane (CH4) generated from low-organic waste degradation at four Danish landfills was estimated by three first-order decay (FOD) landfill gas (LFG) generation models (LandGEM, IPCC, and Afvalzorg). Actual waste data from Danish landfills were applied to fit model (IPCC and Afvalzorg) required...... categories. In general, the single-phase model, LandGEM, significantly overestimated CH4 generation, because it applied too high default values for key parameters to handle low-organic waste scenarios. The key parameters were biochemical CH4 potential (BMP) and CH4 generation rate constant (k.......Implications: Landfill operators use the first-order decay (FOD) models to estimate methane (CH4) generation. A single-phase model (LandGEM) and a traditional model (IPCC) could result in overestimation when handling a low-organic waste scenario. Site-specific data were important and capable of calibrating key parameter...

  4. Immunological aspects and therapeutic significance of an autoantibody against histone H1 in a rat model of concanavalin A-induced hepatitis. (United States)

    Nakano, Toshiaki; Goto, Shigeru; Lai, Chia-Yun; Hsu, Li-Wen; Takaoka, Yuki; Kawamoto, Seiji; Chiang, Kuei-Chen; Shimada, Yayoi; Ohmori, Naoya; Goto, Takeshi; Sato, Shuji; Ono, Kazuhisa; Cheng, Yu-Fan; Chen, Chao-Long


    We previously demonstrated the immunosuppressive activity of anti-histone H1 autoantibody induced in experimental and clinical liver allograft tolerance. This study aimed to explore the immunological aspects of anti-histone H1 autoantibody in liver injury induced by concanavalin A (Con A). To establish a Con A-hepatitis model, 20 mg/kg Con A was intravenously injected into rats, after which liver function and histopathological analyses were performed. In this model, anti-histone H1 autoantibody was transiently induced in the sera during the natural recovery stage, 3-7 days after Con A injection. To evaluate the therapeutic significance of anti-histone H1 autoantibody, a polyclonal antibody against histone H1 was intraperitoneally injected immediately after Con A injection. We found that injection of anti-histone H1 antibody could reduce Con A-induced liver damage. Further mechanical analyses revealed that anti-histone H1 antibody altered the intracellular activation of mitogen-activated protein kinase, nuclear factor-kappaB and calcineurin via T-cell receptor signalling, suggesting that anti-histone H1 antibody may protect the liver from Con A-induced injury by inhibiting activation of effector T cells. These findings suggest that anti-histone H1 autoantibody may be a natural immune regulatory factor that protects inflamed livers suffering from autoimmune hepatitis and may lead to T-cell unresponsiveness through the selective regulation of mitogen-activated protein kinase/nuclear factor-kappaB and calcineurin signalling.

  5. NF-κB inhibition significantly upregulates the norepinephrine transporter system, causes apoptosis in pheochromocytoma cell lines and prevents metastasis in an animal model (United States)

    Pacak, Karel; Sirova, Marta; Giubellino, Alessio; Lencesova, Lubomira; Csaderova, Lucia; Hudecova, Sona; Krizanova, Olga


    Pheochromocytomas (PHEOs) and paragangliomas (PGLs) are specific types of neuroendocrine tumors that originate in the adrenal medulla or sympathetic/parasympathetic paraganglia, respectively. Although these tumors are intensively studied, a very effective treatment for metastatic PHEO or PGL has not yet been established. Preclinical evaluations of novel therapies for these tumors are very much required. Therefore, in the present study we tested the effect of triptolide (TTL), a potent nuclear factor-kappaB (NF-κB) inhibitor, on the cell membrane norepinephrine transporter system (NET), considered to be the gatekeeper for the radiotherapeutic agent 131I-metaiodobenzylguanidine (131I-MIBG). We measured changes in the mRNA and protein levels of NET and correlated them with proapoptotic factors and metastasis inhibition. The study was carried out on three different stable pheochromocytoma cell lines. We found that blocking NF-κB with TTL or capsaicin (KPSC) increased both NET mRNA and protein levels. Involvement of NF-κB in the upregulation of NET was verified by mRNA silencing of this site and also by using NF-κB antipeptide. Moreover, MIBG transport was increased in TTL-treated cells and in vivo treatment with TTL significantly reduced metastatic burden in a metastatic animal model of pheochromocytoma. The present study for the first time shows mechanistically how NF-κB inhibitors can be successfully used in the treatment of metastatic PHEO/PGL by a significant upregulation of NET to increase the efficacy of 131I-MIBG and by the induction of apoptosis. PMID:22407736

  6. Assumed white blood cell count of 8,000 cells/μL overestimates malaria parasite density in the Brazilian Amazon.

    Directory of Open Access Journals (Sweden)

    Eduardo R Alves-Junior

    Full Text Available Quantification of parasite density is an important component in the diagnosis of malaria infection. The accuracy of this estimation varies according to the method used. The aim of this study was to assess the agreement between the parasite density values obtained with the assumed value of 8,000 cells/μL and the automated WBC count. Moreover, the same comparative analysis was carried out for other assumed values of WBCs. The study was carried out in Brazil with 403 malaria patients who were infected in different endemic areas of the Brazilian Amazon. The use of a fixed WBC count of 8,000 cells/μL to quantify parasite density in malaria patients led to overestimated parasitemia and resulted in low reliability when compared to the automated WBC count. Assumed values ranging between 5,000 and 6,000 cells/μL, and 5,500 cells/μL in particular, showed higher reliability and more similar values of parasite density when compared between the 2 methods. The findings show that assumed WBC count of 5,500 cells/μL could lead to a more accurate estimation of parasite density for malaria patients in this endemic region.

  7. Nab-paclitaxel Efficacy in the Orthotopic Model of Human Breast Cancer Is Significantly Enhanced By Concurrent Anti–Vascular Endothelial Growth Factor A Therapy

    Directory of Open Access Journals (Sweden)

    Lisa D. Volk


    Full Text Available Nab-paclitaxel is an albumin-bound 130-nm particle form of paclitaxel that has shown an improved efficacy in experimental tumor models and clinical studies compared with solvent-based paclitaxel. Anti–vascular endothelial growth factor A (VEGF-A antibody bevacizumab is known to enhance antitumor activity of cytotoxic drugs. This study evaluated the effects of combined nab-paclitaxel and bevacizumab therapy on growth and metastatic spread of orthotopic breast tumors. Cytotoxic and clonogenic assays measured VEGF-A–dependent modulation of nabpaclitaxel toxicity on cultured tumor cells. Antitumor effects were assessed in mice with luciferase-tagged, wellestablished MDA-MB-231 tumors (250–310 mm3 treated with one, two, or three cycles of nab-paclitaxel (10 mg/ kg, daily for five consecutive days, bevacizumab (2–8 mg/kg, twice a week, or with combination of both drugs. VEGF-A protected MDA-MB-231 cells against nab-paclitaxel cytotoxicity, whereas bevacizumab sensitized cells to the effect of the drug. Combined bevacizumab and nab-paclitaxel treatment synergistically inhibited tumor growth and metastasis resulting in up to 40% of complete regressions of well-established tumors. This therapy also decreased the incidence of lymphatic and pulmonary metastases by 60% and 100%, respectively. The significant increase in the cure of tumor-bearing mice in the nab-paclitaxel/bevacizumab combined group compared with mice treated with single drugs strongly advocates for implementing such strategy in clinics.

  8. Chronic administration of ethanol leaf extract of Moringa oleifera Lam. (Moringaceae) may compromise glycaemic efficacy of Sitagliptin with no significant effect in retinopathy in a diabetic rat model. (United States)

    Olurishe, Comfort; Kwanashie, Helen; Zezi, Abdulkadiri; Danjuma, Nuhu; Mohammed, Bisalla


    Moringa oleifera Lam. (Moringaceae) has gained awareness for its antidiabetic effect, and is used as alternative therapy or concurrently with orthodox medicines such as sitagliptin in diabetes mellitus. This is without ascertaining the possibility of drug-herb interactions, which could either lead to enhanced antidiabetic efficacy, increased toxicity, or compromised glycaemic control with negative consequence in diabetic retinopathy. To investigate the effect, of sitagliptin (50mg/kg), Moringa oleifera (300mg/kg) leaf extract, and a combination of both on glycaemic control parameters, lenticular opacity and changes in retinal microvasculature in alloxan (150mg/kg i.p) induced diabetic rat model. Seven groups of eight rats per group were used, with groups I, II and VII as normal (NC), diabetic (DC) and post-prandial controls (PPC). Groups III to VI were diabetic rats on sitagliptin (III), M. oleifera (IV), sitagliptin and M. oleifera (SM) (V), for 42 days with 2 weeks delayed treatment in a post-prandial hyperglycaemic group (PPSM) (VI). Glycaemic control parameters, insulin levels, body weights, and effects of retinal microvasculature on lenticular opacity/morphology were investigated. A significant decrease in fasting blood glucose (FBG) levels was displayed in SM group from day 14(60%) (poleifera showed a progressive decrease in anti-hyperglycaemic effect of sitagliptin, and although it delayed the onset of lenticular opacity (i.e. cataract-like changes) it did not prevent the progression nor ameliorated pathologic lesions in the retina. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. SU-E-T-580: On the Significance of Model Based Dosimetry for Breast and Head and Neck 192Ir HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Peppa, V; Pappas, E; Pantelis, E; Papagiannis, P [Medical Physics Laboratory, Medical School, University of Athens, Athens (Greece); Major, T; Polgar, C [National Institute of Oncology, Budapest (Hungary)


    Purpose: To assess the dosimetric and radiobiological differences between TG43-based and model-based dosimetry in the treatment planning of {sup 192}Ir HDR brachytherapy for breast and head and neck cancer. Methods: Two cohorts of 57 Accelerated Partial Breast Irradiation (APBI) and 22 head and neck (H&N) patients with oral cavity carcinoma were studied. Dosimetry for the treatment plans was performed using the TG43 algorithm of the Oncentra Brachy v4.4 treatment planning system (TPS). Corresponding Monte Carlo (MC) simulations were performed using MCNP6 with input files automatically prepared by the BrachyGuide software tool from DICOM RT plan data. TG43 and MC data were compared in terms of % dose differences, Dose Volume Histograms (DVHs) and related indices of clinical interest for the Planning Target Volume (PTV) and the Organs-At-Risk (OARs). A radiobiological analysis was also performed using the Equivalent Uniform Dose (EUD), mean survival fraction (S) and Tumor Control Probability (TCP) for the PTV, and the Normal Tissue Control Probability (N TCP) and the generalized EUD (gEUD) for the OARs. Significance testing of the observed differences performed using the Wilcoxon paired sample test. Results: Differences between TG43 and MC DVH indices, associated with the increased corresponding local % dose differences observed, were statistically significant. This is mainly attributed to their consistency however, since TG43 agrees closely with MC for the majority of DVH and radiobiological parameters in both patient cohorts. Differences varied considerably among patients only for the ipsilateral lung and ribs in the APBI cohort, with a strong correlation to target location. Conclusion: While the consistency and magnitude of differences in the majority of clinically relevant DVH indices imply that no change is needed in the treatment planning practice, individualized dosimetry improves accuracy and addresses instances of inter-patient variability observed. Research

  10. Neuraminidase-1 contributes significantly to the degradation of neuronal B-series gangliosides but not to the bypass of the catabolic block in Tay–Sachs mouse models

    Directory of Open Access Journals (Sweden)

    Z.K. Timur


    Full Text Available Tay–Sachs disease is a severe lysosomal storage disorder caused by mutations in the HEXA gene coding for α subunit of lysosomal β-Hexosaminidase A enzyme, which converts GM2 to GM3 ganglioside. HexA−/− mice, depleted of the β-Hexosaminidase A iso-enzyme, remain asymptomatic up to 1 year of age because of a metabolic bypass by neuraminidase(s. These enzymes remove a sialic acid residue converting GM2 to GA2, which is further degraded by the still intact β-Hexosaminidase B iso-enzyme into lactosylceramide. A previously identified ganglioside metabolizing neuraminidase, Neu4, is abundantly expressed in the mouse brain and has activity against gangliosides like GM2 in vitro. Neu4−/− mice showed increased GD1a and decreased GM1 ganglioside in the brain suggesting the importance of the Neu4 in ganglioside catabolism. Mice with targeted disruption of both HexA and Neu4 genes showed accumulating GM2 ganglioside and epileptic seizures with 40% penetrance, indicating that the neuraminidase Neu4 is a modulatory gene, but may not be the only neuraminidase contributing to the metabolic bypass in HexA−/− mice. Therefore, we elucidated the biological role of neuraminidase-1 in ganglioside degradation in mouse. Analysis of HexA−/−Neu1−/− and HexA−/−Neu4−/−Neu1−/− mice models showed significant contribution of neuraminidase-1 on B-series ganglioside degradation in the brain. Therefore, we speculate that other neuraminidase/neuraminidases such as Neu2 and/or Neu3 might be also involved in the ganglioside degradation pathway in HexA−/− mice.

  11. Neuraminidase-1 contributes significantly to the degradation of neuronal B-series gangliosides but not to the bypass of the catabolic block in Tay-Sachs mouse models. (United States)

    Timur, Z K; Akyildiz Demir, S; Marsching, C; Sandhoff, R; Seyrantepe, V


    Tay–Sachs disease is a severe lysosomal storage disorder caused by mutations in the HEXA gene coding for α subunit of lysosomal β-Hexosaminidase A enzyme, which converts GM2 to GM3 ganglioside. HexA(−/−) mice, depleted of the β-Hexosaminidase A iso-enzyme, remain asymptomatic up to 1 year of age because of a metabolic bypass by neuraminidase(s). These enzymes remove a sialic acid residue converting GM2 to GA2, which is further degraded by the still intact β-Hexosaminidase B iso-enzyme into lactosylceramide. A previously identified ganglioside metabolizing neuraminidase, Neu4, is abundantly expressed in the mouse brain and has activity against gangliosides like GM2in vitro. Neu4(−/−) mice showed increased GD1a and decreased GM1 ganglioside in the brain suggesting the importance of the Neu4 in ganglioside catabolism. Mice with targeted disruption of both HexA and Neu4 genes showed accumulating GM2 ganglioside and epileptic seizures with 40% penetrance, indicating that the neuraminidase Neu4 is a modulatory gene, but may not be the only neuraminidase contributing to the metabolic bypass in HexA(−/−) mice. Therefore, we elucidated the biological role of neuraminidase-1 in ganglioside degradation in mouse. Analysis of HexA(−/−) Neu1(−/−) and HexA(−/−) Neu4(−/−) Neu1(−/−) mice models showed significant contribution of neuraminidase-1 on B-series ganglioside degradation in the brain. Therefore, we speculate that other neuraminidase/neuraminidases such as Neu2 and/or Neu3 might be also involved in the ganglioside degradation pathway in HexA(−/−) mice.

  12. The In Vitro Mass-Produced Model Mycorrhizal Fungus, Rhizophagus irregularis, Significantly Increases Yields of the Globally Important Food Security Crop Cassava (United States)

    Ceballos, Isabel; Ruiz, Michael; Fernández, Cristhian; Peña, Ricardo


    The arbuscular mycorrhizal symbiosis is formed between arbuscular mycorrhizal fungi (AMF) and plant roots. The fungi provide the plant with inorganic phosphate (P). The symbiosis can result in increased plant growth. Although most global food crops naturally form this symbiosis, very few studies have shown that their practical application can lead to large-scale increases in food production. Application of AMF to crops in the tropics is potentially effective for improving yields. However, a main problem of using AMF on a large-scale is producing cheap inoculum in a clean sterile carrier and sufficiently concentrated to cheaply transport. Recently, mass-produced in vitro inoculum of the model mycorrhizal fungus Rhizophagus irregularis became available, potentially making its use viable in tropical agriculture. One of the most globally important food plants in the tropics is cassava. We evaluated the effect of in vitro mass-produced R. irregularis inoculum on the yield of cassava crops at two locations in Colombia. A significant effect of R. irregularis inoculation on yield occurred at both sites. At one site, yield increases were observed irrespective of P fertilization. At the other site, inoculation with AMF and 50% of the normally applied P gave the highest yield. Despite that AMF inoculation resulted in greater food production, economic analyses revealed that AMF inoculation did not give greater return on investment than with conventional cultivation. However, the amount of AMF inoculum used was double the recommended dose and was calculated with European, not Colombian, inoculum prices. R. irregularis can also be manipulated genetically in vitro, leading to improved plant growth. We conclude that application of in vitro R. irregularis is currently a way of increasing cassava yields, that there is a strong potential for it to be economically profitable and that there is enormous potential to improve this efficiency further in the future. PMID:23950975

  13. Modeling Effects on Forces in Shear Wall-Frame Structures

    Directory of Open Access Journals (Sweden)

    Adang Surahman


    Full Text Available Shear walls are added to a structural system to reduce lateral deformations in moment resisting frames and are designed to carry a major portion of lateral load induced by an earthquake. A small percentage error in the shear wall calculation will have a significant effect on the frame forces. The results show that even a slight difference in structural assumption, or modeling, results in significant differences. Some of these differences are beyond the values that are covered by safety factors for errors in modeling. The differences are more obvious in the upper stories. It is not recommended to overestimate shear wall stiffness, nor underestimate frame stiffness.

  14. Modification of the vertically generalized production model for the turbid waters of Ariake Bay, southwestern Japan (United States)

    Tripathy, S. C.; Ishizaka, J.; Siswanto, E.; Shibata, T.; Mino, Y.


    The vertically generalized production model (VGPM), which was designed for open ocean waters ( Behrenfeld and Falkowski, 1997a; henceforth BF), was evaluated using in situ measurements of primary productivity (PP) in the characteristically turbid coastal waters of Ariake Bay, southwestern Japan, to develop a regionally modified version of the model. The euphotic depth ( Z eu)-integrated PP (IPP) calculated from the VGPM using in situ chlorophyll a (Chl a) and sea surface temperature (SST) was significantly overestimated (by factors of 2-3), but 52% of the observed variability was explained. The weak correlation could have partially resulted from overestimations by the sub-models embedded in the original VGPM model for estimation of Z eu ( Morel and Berthon, 1989; henceforth MB) and the optimal Chl a-normalized PP ( poptB). The sub-model estimates of poptB and Z eu with in situpoptB and Z eu showed significant improvement, accounting for 84% of the variability and causing less overestimation. Z eu was the most important parameter influencing the modeled IPP variation in Ariake Bay. Previous research suggested that the Z eu model, which was based on surface Chl a, overestimated in situ Z eu by a factor of 2-3, resulting in weak correlation between the modeled and in situ IPP. The Z eu sub-model was not accurate in the present study area because it was basically developed for clear (case 1) waters. A better estimation of Z eu could be obtained from the in situ remote sensing reflectance ( R rs) using a quasi-analytical algorithm (QAA) in this turbid water ecosystem. Among the parameters of PP models, poptB is conventionally considered the most important. However, in this study poptB was of secondary importance because the contribution of poptB to the variation in modeled IPP was less than the contribution of Z eu. The modeled and in situpoptB were weakly correlated with 50% of the data points that overestimated the in situ values. The estimation of Chl a was improved

  15. Statistical significance of seasonal warming/cooling trends (United States)

    Ludescher, Josef; Bunde, Armin; Schellnhuber, Hans Joachim


    The question whether a seasonal climate trend (e.g., the increase of summer temperatures in Antarctica in the last decades) is of anthropogenic or natural origin is of great importance for mitigation and adaption measures alike. The conventional significance analysis assumes that (i) the seasonal climate trends can be quantified by linear regression, (ii) the different seasonal records can be treated as independent records, and (iii) the persistence in each of these seasonal records can be characterized by short-term memory described by an autoregressive process of first order. Here we show that assumption ii is not valid, due to strong intraannual correlations by which different seasons are correlated. We also show that, even in the absence of correlations, for Gaussian white noise, the conventional analysis leads to a strong overestimation of the significance of the seasonal trends, because multiple testing has not been taken into account. In addition, when the data exhibit long-term memory (which is the case in most climate records), assumption iii leads to a further overestimation of the trend significance. Combining Monte Carlo simulations with the Holm-Bonferroni method, we demonstrate how to obtain reliable estimates of the significance of the seasonal climate trends in long-term correlated records. For an illustration, we apply our method to representative temperature records from West Antarctica, which is one of the fastest-warming places on Earth and belongs to the crucial tipping elements in the Earth system.

  16. Fatores biológicos e superestimação da fração de ejeção do ventrículo esquerdo no gated SPECT Biological factors and overestimation of left ventricular ejection fraction by gated SPECT

    Directory of Open Access Journals (Sweden)

    Marco Antônio Condé de Oliveira


    (from 33.5 to 150 kg - mean: 79.6 kg, height (from 138 to 220 cm - mean: 171 cm and BMI (from 13.9 to 54 - mean: 27.2. In a subgroup of 1002 patients who underwent echocardiogram, the diastolic diameter (from 36 to 68 mm - mean 47.5 mm and systolic diameter (from 22 to 41 mm - mean 29.8 mm variables were included. The patients were divided into two groups: normal LVEF (80%. The odds ratio (OR for presenting an overestimated LVEF was calculated for each variable using logistic regression. RESULTS: The following odds ratios were found (p 0.2. In the subgroup of 1002 patients, a statistically significant influence was found in overestimated LVEF values for the systolic diameter, gender and height variables. CONCLUSION: Although systolic diameter influences the overestimation of LVEF, the gender and height variables have an independent influence on LVEF overestimation by gated SPECT.

  17. Meaning and significance of

    Directory of Open Access Journals (Sweden)

    Ph D Student Roman Mihaela


    Full Text Available The concept of "public accountability" is a challenge for political science as a new concept in this area in full debate and developement ,both in theory and practice. This paper is a theoretical approach of displaying some definitions, relevant meanings and significance odf the concept in political science. The importance of this concept is that although originally it was used as a tool to improve effectiveness and eficiency of public governance, it has gradually become a purpose it itself. "Accountability" has become an image of good governance first in the United States of America then in the European Union.Nevertheless,the concept is vaguely defined and provides ambiguous images of good governance.This paper begins with the presentation of some general meanings of the concept as they emerge from specialized dictionaries and ancyclopaedies and continues with the meanings developed in political science. The concept of "public accontability" is rooted in economics and management literature,becoming increasingly relevant in today's political science both in theory and discourse as well as in practice in formulating and evaluating public policies. A first conclusin that emerges from, the analysis of the evolution of this term is that it requires a conceptual clarification in political science. A clear definition will then enable an appropriate model of proving the system of public accountability in formulating and assessing public policies, in order to implement a system of assessment and monitoring thereof.

  18. Testing Model Atmospheres for Young Very-low-mass Stars and Brown Dwarfs in the Infrared: Evidence for Significantly Underestimated Dust Opacities (United States)

    Tottle, Jonathan; Mohanty, Subhanjoy


    We test state-of-the-art model atmospheres for young very-low-mass stars and brown dwarfs in the infrared, by comparing the predicted synthetic photometry over 1.2-24 μm to the observed photometry of M-type spectral templates in star-forming regions. We find that (1) in both early and late young M types, the model atmospheres imply effective temperatures ({{T}eff}) several hundred Kelvin lower than predicted by the standard pre-main sequence (PMS) spectral type-{{T}eff} conversion scale (based on theoretical evolutionary models). It is only in the mid-M types that the two temperature estimates agree. (2) The {{T}eff} discrepancy in the early M types (corresponding to stellar masses ≳ 0.4 {{M}⊙ } at ages of a few Myr) probably arises from remaining uncertainties in the treatment of atmospheric convection within the atmospheric models, whereas in the late M types it is likely due to an underestimation of dust opacity. (3) The empirical and model-atmosphere J-band bolometric corrections are both roughly flat, and similar to each other, over the M-type {{T}eff} range. Thus the model atmospheres yield reasonably accurate bolometric luminosities ({{L}bol}), but lead to underestimations of mass and age relative to evolutionary expectations (especially in the late M types) due to lower {{T}eff}. We demonstrate this for a large sample of young Cha I and Taurus sources. (4) The trends in the atmospheric model J-Ks colors, and their deviations from the data, are similar at PMS and main sequence ages, suggesting that the model dust opacity errors we postulate here for young ages also apply at field ages.

  19. Significant Findings: Seasonal Distributions of Global Ocean Chlorophyll and Nutrients With a Coupled Ocean General Circulation, Biogeochemical, and Radiative Model. 2; Comparisons With Satellite and In Situ Data (United States)

    Gregg, Watson W.; Busalacchi, Antonio (Technical Monitor)


    A coupled ocean general circulation, biogeochemical, and radiative model was constructed to evaluate and understand the nature of seasonal variability of chlorophyll and nutrients in the global oceans. Biogeochemical processes in the model were determined from the influences of circulation and turbulence dynamics, irradiance availability, and the interactions among three functional phytoplankton groups (diatoms, chlorophytes, and picoplankton) and three nutrients (nitrate, ammonium, and silicate). Basin scale (>1000 km) model chlorophyll seasonal distributions were statistically positively correlated with CZCS chlorophyll in 10 of 12 major oceanographic regions, and with SeaWiFS in all 12. Notable disparities in magnitudes occurred, however, in the tropical Pacific, the spring/summer bloom in the Antarctic, autumn in the northern high latitudes, and during the southwest monsoon in the North Indian Ocean. Synoptic scale (100-1000 km) comparisons of satellite and in situ data exhibited broad agreement, although occasional departures were apparent. Model nitrate distributions agreed with in situ data, including seasonal dynamics, except for the equatorial Atlantic. The overall agreement of the model with satellite and in situ data sources indicated that the model dynamics offer a reasonably realistic simulation of phytoplankton and nutrient dynamics on basin and synoptic scales.

  20. The contribution of aerosol hygroscopic growth to the modeled aerosol radiative effect (United States)

    Kokkola, Harri; Kühn, Thomas; Kirkevåg, Alf; Romakkaniemi, Sami; Arola, Antti


    The hygroscopic growth of atmospheric aerosols can have a significant effect on the direct radiative effect of atmospheric aerosol. However, there are significant uncertainties concerning how much of the radiative forcing is due to different chemical compounds, especially water. For example, modeled optical depth of water in global aerosol-climate models varies by more than a factor of two. These differences can be attributed to differences in modeled 1) hygroscopicity, 2) ambient relative humidity, and/or 3) aerosol size distribution. In this study, we investigate which of these above-mentioned factors cause the largest variability in the modeled optical depth of water. In order to do this, we have developed a tool that calculates aerosol extinction using interchangeable global 3D data of aerosol composition, relative humidity, and aerosol size distribution fields. This data is obtained from models that have taken part in the open international initiative AeroCom (Aerosol Comparisons between Observations and Models). In addition, we use global 3D data for relative humidity from the Atmospheric Infrared Sounder (AIRS) flying on board NASA's Aqua satellite and the National Centers for Environmental Prediction (NCEP) reanalysis data. These observations are used to evaluate the modeled relative humidity fields. In the first stage of the study, we made a detailed investigation using the aerosol-chemistry-climate model ECHAM-HAMMOZ in which most of the aerosol optical depth is caused by water. Our results show that the model significantly overestimates the relative humidity over the oceans while over land, the overestimation is lower or it is underestimated. Since this overestimation occurs over the oceans, the water optical depth is amplified as the hygroscopic growth is very sensitive to changes in high relative humidities. Over land, error in modeled relative humidity is unlikely to cause significant errors in water optical depth as relative humidities are generally

  1. Evaluation and clinical significance of the stomach age model for evaluating aging of the stomach-a multicenter study in China (United States)


    Background A higher prevalence of chronic atrophic gastritis (CAG) occurs in younger adults in Asia. We used Stomach Age to examine the different mechanisms of CAG between younger adults and elderly individuals, and established a simple model of cancer risk that can be applied to CAG surveillance. Methods Stomach Age was determined by FISH examination of telomere length in stomach biopsies. Δψm was also determined by flow cytometry. Sixty volunteers were used to confirm the linear relationship between telomere length and age while 120 subjects were used to build a mathematical model by a multivariate analysis. Overall, 146 subjects were used to evaluate the validity of the model, and 1,007 subjects were used to evaluate the relationship between prognosis and Δage (calculated from the mathematical model). ROC curves were used to evaluate the relationship between prognosis and Δage and to determine the cut-off point for Δage. Results We established that a tight linear relationship between the telomere length and the age. The telomere length was obvious different between patients with and without CAG even in the same age. Δψm decreased in individuals whose Stomach Age was greater than real age, especially in younger adults. A mathematical model of Stomach Age (real age + Δage) was successfully constructed which was easy to apply in clinical work. A higher Δage was correlated with a worse outcome. The criterion of Δage >3.11 should be considered as the cut-off to select the subgroup of patients who require endoscopic surveillance. Conclusion Variation in Stomach Age between individuals of the same biological age was confirmed. Attention should be paid to those with a greater Stomach Age, especially in younger adults. The Δage in the Simple Model can be used as a criterion to select CAG patients for gastric cancer surveillance. PMID:25057261

  2. Assessing the performance characteristics and clinical forces in simulated shape memory bone staple surgical procedure: The significance of SMA material model. (United States)

    Saleeb, A F; Dhakal, B; Owusu-Danquah, J S


    This work is focused on the detailed computer simulation of the key stages involved in a shape memory alloy (SMA) osteosynthesis bone stapling procedure. To this end, a recently developed three-dimensional constitutive SMA material model was characterized from test data of three simple uniaxial-isothermal-tension experiments for powder metallurgically processed nickel-rich NiTi (PM/NiTi-P) material. The calibrated model was subsequently used under the complex, thermomechanical loading conditions involved in the surgical procedure using the body-temperature-activated PM/NiTi-P bone staple. Our aim here is to assess the immediate and post-surgical performance characteristics of the stapling operation using the material model. From this study: (1) it was found that adequate compressive forces were developed by the PM/NiTi-P bone staple, with the tendency of this force to even increase under sustained thermal loading due to the intrinsic "inverse relaxation phenomena" in the SMA material, (2) the simulation results correlated well with those from experimental measurements, (3) the body-temperature-activated PM/NiTi-P staple was proved to be clinically viable, providing a stable clamping force needed for speedy coaptation of the fractured bones, and (4) these realistic assessments crucially depend on the use of suitable and comprehensive SMA material models. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Significance of Cultural-Historical Theory of Psychological Development of L.S. Vygotsky for the Development of Modern Models of Social Cognition and Psychotherapy

    Directory of Open Access Journals (Sweden)

    Kholmogorova A.B.,


    Full Text Available The article acknowledges the situation of methodical crisis in modern research of social cognition related to the domination of reductive approaches that ignore the uniqueness of human psyche. Heuristicity of concepts of cultural-historical theory of psychological development of L.S. Vygotsky, which serves to overcome the apparent inconsistencies is substantiated. Models of social cognition based on the principles of cultural-historical psychology are described, those being the model of social cognition within phylogenesis of M. Tomasello, and the model of social cognition within ontogenesis of C. Fernyhough. Current situation in the area of mental health is reviewed from the standpoint of cultural-historical psychology, its specifics reflected in the increased burden on reflexive functions, that is, skills lying within the sphere of social cognition is substantiated. Modern psychotherapeutic apparatus directed to compensate social cognition deficits due to various psychiatric disorders is reviewed. The assumption that adolescense is sensitive period for the development of higher forms of social cognition is made, and a summary of researches supporting this assertion is presented. Main contradictions of modern-day maturing are enunciated. To conclude the presented theoretical analysis, a comprehensive multiple-factor model of social cognition is presented based on concepts of cultural-historical theory of L.S. Vygotsky.

  4. Calculation of limits for significant bidirectional changes in two or more serial results of a biomarker based on a computer simulation model

    DEFF Research Database (Denmark)

    Lund, Flemming; Petersen, Per Hyltoft; Fraser, Callum G;


    .01). RESULTS: From an individual factors used to multiply the first result were calculated to create limits for constant cumulated significant changes. The factors were shown to become a function of the number of results included and the total coefficient of variation. CONCLUSIONS: The first result should...

  5. Significant NRC Enforcement Actions (United States)

    Nuclear Regulatory Commission — This dataset provides a list of Nuclear Regulartory Commission (NRC) issued significant enforcement actions. These actions, referred to as "escalated", are issued by...

  6. Methods and significances of constructing animal models infected with Toxoplasma gondii%构建弓形虫病动物模型的方法和意义

    Institute of Scientific and Technical Information of China (English)

    刘媛; 谷俊朝


    Toxoplasmosis gondii is a common parasitic zoonoses worldwide.Construction of animal model is one of the most important ways to study it.To investigate the processes and outcomes after infection by using different animal models has provided a favorable experimental basis in preventing and curing toxoplasmosis which is far-reaching beneficial for human health.%目的 弓形虫病是世界范围内的人兽共患寄生虫病.构建动物模型是研究弓形虫病的重要途径之一.利用不同的动物模型来探索弓形虫感染后的发病过程及转归,为预防及治疗弓形虫病提供了良好的动物实验基础,对人类的健康发展有着深远的意义.

  7. The measure and significance of Bateman's principles. (United States)

    Collet, Julie M; Dean, Rebecca F; Worley, Kirsty; Richardson, David S; Pizzari, Tommaso


    Bateman's principles explain sex roles and sexual dimorphism through sex-specific variance in mating success, reproductive success and their relationships within sexes (Bateman gradients). Empirical tests of these principles, however, have come under intense scrutiny. Here, we experimentally show that in replicate groups of red junglefowl, Gallus gallus, mating and reproductive successes were more variable in males than in females, resulting in a steeper male Bateman gradient, consistent with Bateman's principles. However, we use novel quantitative techniques to reveal that current methods typically overestimate Bateman's principles because they (i) infer mating success indirectly from offspring parentage, and thus miss matings that fail to result in fertilization, and (ii) measure Bateman gradients through the univariate regression of reproductive over mating success, without considering the substantial influence of other components of male reproductive success, namely female fecundity and paternity share. We also find a significant female Bateman gradient but show that this likely emerges as spurious consequences of male preference for fecund females, emphasizing the need for experimental approaches to establish the causal relationship between reproductive and mating success. While providing qualitative support for Bateman's principles, our study demonstrates how current approaches can generate a misleading view of sex differences and roles.

  8. Dosimetric Significance of the ICRP's Updated Guidance and Models, 1989-2003, and Implications for U.S. Federal Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, R.W.


    Over the past two decades the U.S. Environmental Protection Agency (EPA) has issued a series of Federal guidance documents for the purpose of providing the Federal and State agencies with technical information to assist their implementation of radiation protection programs. Currently recommended dose conversion factors, annual limits on intake, and derived air concentrations for intake of radionuclides are tabulated in Federal Guidance Report No. 11 (FGR 11), published in 1988. The tabulations in FGR 11 were based on dosimetric quantities and biokinetic and dosimetric models of the International Commission on Radiological Protection (ICRP) developed for application to occupational exposures. Since the publication of FGR 11 the ICRP has revised some of its dosimetric quantities and its models for workers and has also developed age-specific models and dose conversion factors for intake of radionuclides by members of the public. This report examines the extent of the changes in the inhalation and ingestion dose coefficients of FGR 11 implied by the updated recommendations of the ICRP, both for workers and members of the public.

  9. The B-Raf status of tumor cells may be a significant determinant of both antitumor and anti-angiogenic effects of pazopanib in xenograft tumor models.

    Directory of Open Access Journals (Sweden)

    Brunilde Gril

    Full Text Available Pazopanib is an FDA approved Vascular Endothelial Growth Factor Receptor inhibitor. We previously reported that it also inhibits tumor cell B-Raf activity in an experimental brain metastatic setting. Here, we determine the effects of different B-Raf genotypes on pazopanib efficacy, in terms of primary tumor growth and anti-angiogenesis. A panel of seven human breast cancer and melanoma cell lines harboring different mutations in the Ras-Raf pathway was implanted orthotopically in mice, and tumor growth, ERK1/2, MEK1/2 and AKT activation, and blood vessel density and permeability were analyzed. Pazopanib was significantly inhibitory to xenografts expressing either exon 11 mutations of B-Raf, or HER2 activated wild type B-Raf; no significant inhibition of a xenograft expressing the common V600E B-Raf mutation was observed. Decreased pMEK staining in the responsive tumors confirmed that B-Raf was targeted by pazopanib. Interestingly, pazopanib inhibition of tumor cell B-Raf also correlated with its anti-angiogenic activity, as quantified by vessel density and area. In conclusion, using pazopanib, tumor B-Raf status was identified as a significant determinant of both tumor growth and angiogenesis.

  10. The risk of overestimating the risk-metal leaching to groundwater near contaminated glass waste deposits and exposure via drinking water. (United States)

    Augustsson, A; Uddh Söderberg, T; Jarsjö, J; Åström, M; Olofsson, B; Balfors, B; Destouni, G


    This study investigates metal contamination patterns and exposure to Sb, As, Ba, Cd and Pb via intake of drinking water in a region in southeastern Sweden where the production of artistic glass has resulted in a large number of contaminated sites. Despite high total concentrations of metals in soil and groundwater at the glassworks sites properties, all drinking water samples from households with private wells, located at a 30-640m distance from a glassworks site, were below drinking water criteria from the WHO for Sb, As, Ba and Cd. A few drinking water samples showed concentrations of Pb above the WHO guideline, but As was the only element found in concentrations that could result in human exposure near toxicological reference values. An efficient retention of metals in the natural soil close to the source areas, which results in a moderate impact on local drinking water, is implied. Firstly, by the lack of significant difference in metal concentrations when comparing households located upstream and downstream of the main waste deposits, and secondly, by the lack of correlation between the metal concentration in drinking water and distance to the nearest glassworks site. However, elevated Pb and Cd concentrations in drinking water around glassworks sites when compared to regional groundwater indicate that diffuse contamination of the soils found outside the glassworks properties, and not only the glass waste landfills, may have a significant impact on groundwater quality. We further demonstrate that different mobilization patterns apply to different metals. Regarding the need to use reliable data to assess drinking water contamination and human exposure, we finally show that the conservative modelling approaches that are frequently used in routine risk assessments may result in exposure estimates many times higher than those based on measured concentrations in the drinking water that is actually being used for consumption.

  11. Choosing Outcomes of Significance. (United States)

    Spady, William G.


    Outcomes are high-quality, culminating demonstrations of significant learning in context. The High Success Network uses the "Demonstration Mountain" to differentiate among three major "learning zones" and six different forms of learning demonstrations that increase in complexity, generalizability, and significance, along with…

  12. Evaluation of the aerosol models for SeaWiFS and MODIS by AERONET data over open oceans. (United States)

    He, Xianqiang; Pan, Delu; Bai, Yan; Zhu, Qiankun; Gong, Fang


    The operational atmospheric correction algorithm for Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer (MODIS) uses the predefined aerosol models to retrieve aerosol optical properties, and their accuracy depends on how well the aerosol models can represent the real aerosol optical properties. In this paper, we developed a method to evaluate the aerosol models (combined with the model selection methodology) by simulating the aerosol retrieval using the Aerosol Robotic Network (AERONET) data. Our method can evaluate the ability of aerosol models themselves, independent of the sensor performance. Two types of aerosol models for SeaWiFS and MODIS operational atmospheric correction algorithms are evaluated over global open oceans, namely the GW1994 models and Ahmad2010 models. The results show that GW1994 models significantly overestimate the aerosol optical thicknesses and underestimate the Ångström exponent, which is caused by the underestimation of the scattering phase function. However, Ahmad2010 models can significantly reduce the overestimation of the aerosol optical thickness and the underestimation of the Ångström exponent as a whole, but this improvement depends on the backscattering angle. Ahmad2010 models have a significant improvement in the retrieval of the aerosol optical thickness at a backscattering angle less than 140°. For a backscattering angle larger than 140°, GW1994 models are better at retrieving the aerosol optical thickness than the Ahmad2010 models.

  13. Revisiting multiple models of progression of β-cell loss of function in type 1 diabetes: Significance for prevention and cure. (United States)

    Li, Xia; Cheng, Jin; Zhou, Zhiguang


    Type 1 diabetes (T1D) results from a chronic autoimmune process that leads to β-cell destruction and exogenous insulin dependence. The natural history of T1D proposed by Eisenbarth suggested six relatively independent stages over the course of the entire disease process, which was considered to be linear and chronic. Based on this classical theory, immunotherapies aim to prevent or reverse all these periods of β-cell loss. Over the past 30 years, much novel information about the pathogenesis of T1D proved that there are complex metabolic changes occurring throughout the entire disease process. Therefore, new possible models for the natural history of the disease have been proposed; these models, in turn, may help facilitate fresh avenues for the prevention and cure of T1D. Herein, we briefly review recent findings in this field of research, with the aim of providing a better theoretical basis for clinical practice. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

  14. Expression and Significance of NF-κB, IL-1β and COX-2 in the Murine Model of Estrogen-dependent Experimental Vulvovaginal Candidiasis

    Institute of Scientific and Technical Information of China (English)

    Xue-rong CHEN; Ya-li LIU; Dun-zhen XIAO; Jun GAO


    Objective To investigate the possible role of estrogen in the pathogenesis of vulvovaginal candidiasis(VVC).Methods Estrogen-dependent experimental murine model of C. albicans vaginal infection was established by injecting subcutaneously with estradiol benzoate and then 5 × 106 stationary-phase C. albicans blastoconidia was inoculated intravaginally to mice (group EI),and other 3 groups were set up: estrogen-treated but not infected (group E) ;estrogen-untreated but infected (group Ⅰ);normal control (group C).The dynamic change of colony-forming unit (CFU) of cervivovaginal lavage fluid was observed. Vaginal tissues at different time points (d 2,d 4,d 7 and d 14) after inoculation of C.albicans were obtained.In situ hybridization staining was used to detect expression of on d 4 and d 7 (P<0.01).Conclusions In the murine model of estrogen-dependent experimental VVC,estrogen promotes the infection establishment by up-regulating expression of CO X-2 via activating NF-κB signal pathway,and the high expression of COX-2 promoted by the interaction of IL-1β and NF-κB after infection formation was involved in persistence of infection.

  15. Practice exploration and significance of metaphor translation teaching model%隐喻翻译教学模式的实践探索与意义研究

    Institute of Scientific and Technical Information of China (English)



    Metaphor translation teaching model is a kind of teaching mode in true translation teaching, the student's metaphorical thinking ability training as a direction, is to improve students' translation competence. Through the practice of metaphor translation teaching model that helps students’ cognition of the world, to improve the students’ ability of cross culture communication.%隐喻翻译教学模式就是在真实的翻译教学中,对学生的隐喻思维能力的练习做一个方向性的指导,是以提高学生翻译能力为目的的一种教学培养模式。通过对隐喻翻译教学模式的实践探索可知其有利于学生在翻译中以隐喻思维认知世界,有利于提高学生的跨文化交际能力。

  16. Quantitative Metaproteomics and Activity-Based Probe Enrichment Reveals Significant Alterations in Protein Expression from a Mouse Model of Inflammatory Bowel Disease. (United States)

    Mayers, Michael D; Moon, Clara; Stupp, Gregory S; Su, Andrew I; Wolan, Dennis W


    Tandem mass spectrometry based shotgun proteomics of distal gut microbiomes is exceedingly difficult due to the inherent complexity and taxonomic diversity of the samples. We introduce two new methodologies to improve metaproteomic studies of microbiome samples. These methods include the stable isotope labeling in mammals to permit protein quantitation across two mouse cohorts as well as the application of activity-based probes to enrich and analyze both host and microbial proteins with specific functionalities. We used these technologies to study the microbiota from the adoptive T cell transfer mouse model of inflammatory bowel disease (IBD) and compare these samples to an isogenic control, thereby limiting genetic and environmental variables that influence microbiome composition. The data generated highlight quantitative alterations in both host and microbial proteins due to intestinal inflammation and corroborates the observed phylogenetic changes in bacteria that accompany IBD in humans and mouse models. The combination of isotope labeling with shotgun proteomics resulted in the total identification of 4434 protein clusters expressed in the microbial proteomic environment, 276 of which demonstrated differential abundance between control and IBD mice. Notably, application of a novel cysteine-reactive probe uncovered several microbial proteases and hydrolases overrepresented in the IBD mice. Implementation of these methods demonstrated that substantial insights into the identity and dysregulation of host and microbial proteins altered in IBD can be accomplished and can be used in the interrogation of other microbiome-related diseases.

  17. Significance Testing Without Truth (United States)


    ICES REPORT 12-34 August 2012 Significance testing without truth by William Perkins, Mark Tygert, and Rachel Ward The Institute for Computational...testing without truth , ICES REPORT 12-34, The Institute for Computational Engineering and Sciences, The University of Texas at Austin, August 2012...2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Significance testing without truth 5a. CONTRACT NUMBER 5b

  18. [The significance of the results of crash-tests with the use of the models of the pedestrians' lower extremities for the prevention of the traffic road accidents]. (United States)

    Smirenin, S A; Fetisov, V A; Grigoryan, V G; Gusarov, A A; Kucheryavets, Yu O

    The disabling injuries inflicted during road traffic accidents (RTA) create a serious challenge for the public health services and are at the same time a major socio-economic problem in the majority of the countries throughout the world. The injuries to the lower extremities of the pedestrians make up the largest fraction of the total number of the non-lethal RTA injuries. Most of them are responsible for the considerable deterioration of the quality of life for the participants in the accidents during the subsequent period. The objective of the present study was to summarize the currently available results of experimental testing of the biomechanical models of the pedestrians' lower extremities in the framework of the program for the prevention of the road traffic accidents as proposed by the World Health Organization (WHO, 2004). The European Enhanced Safety Vehicle Committee (EEVC) has developed a series of crash-tests with the use of the models of the pedestrians' lower extremities simulating the vehicle bumper-pedestrian impact. The models are intended for the assessment of the risk of the tibia fractures and the injuries to the knee joint ligaments. The experts of EEVC proposed the biomechanical criteria for the acceleration of the knee and talocrural parts of the lower limbs as well as for the shear displacement of the knee and knee-bending angle. The engineering solution of this problem is based on numerous innovation proposals being implemented in the machine-building industry with the purpose of reducing the stiffness of structural elements of the bumper and other front components of a modern vehicle designed to protect the pedestrians from severe injuries that can be inflicted in the road traffic accidents. The activities of the public health authorities (in the first place, bureaus of forensic medical expertise and analogous facilities) have a direct bearing on the solution of the problem of control of road traffic injuries because they are possessed of

  19. Grey Model of Behavior Appraisal and its Regulation Significance%行为评价的灰色模型及其监管意义

    Institute of Scientific and Technical Information of China (English)

    孙劲峰; 晏路明


    为了自为地生成和积累市场个体的行为数据,促进行政监管和信用建设现代化,基于管理梳理、研究综合和文献分析并引入灰色理论与监管原理,建立行为类别记录衍生行为档次结构的理论基础与区间灰数,给出基于行为档次区间灰数且兼容监管操作的系统模型及重要说明;指出灰数设定应当体现准确裁断、合理容忍及奖罚协调三个监管梯度逻辑.行为档次的区间灰数设定具有重要的监管操作意义和科学的数据规范功能,模型切合灰色理论的内涵和科学监管的需要,经某种待定信息补充与数学约束后可求解.%To produce and accumulate behavior data of market-body self-conscious, and boost modernization of administrative regulation and credit construction, based on management hackling、 research synthesis and literature analysis,and grey system and regulation principle,theoretical foundations and interval grey number in spreading behavior category record of the market individual to behavior appraisal structure was established, system model and important explanations based on grey numbers of behavior grades and compatible with regulation operation was produced, three gradient logic in regulation including accurately cutting、 rational toleration and reward penalty coordination which should be embodied in grey number enactment are proposed. The interval grey number enactment of behavior grades possesses important meanings in regulation operation and scientific function in data standard,the model agrees with connotation of grey theory and needs of scientific regulation,and is solvable by some undetermined help of information supplement and its mathematical constraints.

  20. Evolution and Significance of the Medical Science Development Model%医学科学发展模式的演化及其意义

    Institute of Scientific and Technical Information of China (English)

    于双成; 刘汉君; 刘彬


    作为科技哲学研究的一个核心命题,以往对科学发展模式的研究基本基于自然科学,尤其是物理学的发展,鲜有关于考证医学发展的研究。医学科学发展模式,决定了医学认识能力的内涵及形成机制,更决定着医学教育的走向。鉴于信息时代的背景,将现代医学科学的发展概括为两种模式———以科学假说为核心的实证探索和以信息综合为主要方式的理论创新。蕴含其中的本质特征,分别是以充分挖掘丰富的网络信息为前提和以工具性医学方法学的支撑为保障,由此而形成医学创新能力培养的新思路———强化医学方法学课程群建设及教学模式的更新。%As a core proposition of philosophy of science and technology ,the previous research on the mode of scientific development has been basically based on the development of the natural science ,especially the development of physics , while the research on the development of medical sciences was rare .Medical science development mode determines the meaning and the formation mechanism of the medical cognitive ability ,even the direction of medical education .In view of the background of the information age ,the development of modern medical science was generalized to the two models ,the empirical explores taking scientific hypothesis as the core and the theoretical innovation taking information comprehensive as the main way .Their essential characteristics are taking fully exploration on the rich information of network as the precondition and taking the supports of the instrumental medical methodologies as the safeguard .Thereby ,the new ideas in cultivating medical innovation ability are formed to strengthen the construction of the courses of group medical methodologies and update the teaching models .

  1. Disruption of the 5S RNP-Mdm2 interaction significantly improves the erythroid defect in a mouse model for Diamond-Blackfan anemia. (United States)

    Jaako, P; Debnath, S; Olsson, K; Zhang, Y; Flygare, J; Lindström, M S; Bryder, D; Karlsson, S


    Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia caused by haploinsufficiency of genes encoding ribosomal proteins (RPs). Perturbed ribosome biogenesis in DBA has been shown to induce a p53-mediated ribosomal stress response. However, the mechanisms of p53 activation and its relevance for the erythroid defect remain elusive. Previous studies have indicated that activation of p53 is caused by the inhibition of mouse double minute 2 (Mdm2), the main negative regulator of p53, by the 5S ribonucleoprotein particle (RNP). Meanwhile, it is not clear whether this mechanism solely mediates the p53-dependent component found in DBA. To approach this question, we crossed our mouse model for RPS19-deficient DBA with Mdm2(C305F) knock-in mice that have a disrupted 5S RNP-Mdm2 interaction. Upon induction of the Rps19 deficiency, Mdm2(C305F) reversed the p53 response and improved expansion of hematopoietic progenitors in vitro, and ameliorated the anemia in vivo. Unexpectedly, disruption of the 5S RNP-Mdm2 interaction also led to selective defect in erythropoiesis. Our findings highlight the sensitivity of erythroid progenitor cells to aberrations in p53 homeostasis mediated by the 5S RNP-Mdm2 interaction. Finally, we provide evidence indicating that physiological activation of the 5S RNP-Mdm2-p53 pathway may contribute to functional decline of the hematopoietic system in a cell-autonomous manner over time.

  2. Potential triple helix-mediated inhibition of IGF-I gene expression significantly reduces tumorigenicity of glioblastoma in an animal model. (United States)

    Shevelev, A; Burfeind, P; Schulze, E; Rininsland, F; Johnson, T R; Trojan, J; Chernicky, C L; Hélène, C; Ilan, J; Ilan, J


    Oligonucleotide-directed triple helix formation is a powerful approach to block transcription of specific genes. Although the oligonucleotide triplex approach is efficient for inhibiting gene expression in cultured cells, suppression is transient. We developed an approach which inhibits insulin-like growth factor-I (IGF-I) expression following stable transfection of C6 rat glioblastoma cells with a plasmid from which an RNA is transcribed that codes for the third strand of a potential triple helix. We tested the ability of this expression vector to inhibit IGF-I gene expression in vitro as well as tumorigenesis in an animal. A dramatic reduction of IGF-I RNA and protein levels in cultured cells occurred following transfection of rat C6 cells with a eukaryotic expression plasmid encoding the oligopurine variant of the triple helix but not the oligopyrimidine or a control sequence. The cells transfected with the oligopurine variant displayed morphological changes, upregulation of major histocompatibility complex I, and increased expression of protease nexin I. Dramatic inhibition of tumor growth occurred in nude mice following injection of transfected C6 cells. To our knowledge, this is the first example of tumor growth inhibition in an animal model employing a triple helix approach.

  3. Significance of incorporation of model for end-stage liver disease score with TNM staging in patients with hepatocellular carcinoma undergoing hepatic resection. (United States)

    Ling, Ching-Hsien; Chau, Gar-Yang; Hsia, Chen-Yuan; King, Kuang-Liang


    Currently, the tumor-node-metastasis (TNM) system is used in hepatectomy patients for tumor staging of HCC patients. However this can only evaluate the histopathological factor. MELD score is an objective measure for liver function widely used as a severity index for priority on the waiting list for liver transplantation. Here we suggest a modified TNM staging system based on the MELD score and test its relation with post-operative outcome of HCC. We retrospectively collected 922 HCC patients undergoing hepatic resection, with TNM stage I (n=239), stage II (n=375) and stage III (n=308); giving points 0 to 2 for each stage (from I to III). Pre-operative MELD score was calculated and assigned 0 points for MELD 8. The two scores were added together to form a modified MELD-base TNM stage score and tested the correlation of this new scoring system with outcome after liver resection. The modified MELD-base TNM stage score resulted in score 0 (n=114), score 1 (n=247), score 2 (n=335), score 3 (n=164), and score 4 (n=62). The disease-free survival in each group showed significant difference (pTNM staging system reliably separates patients with HCC into homogeneous groups with respect to post-resectional prognosis. Further prospective validation studies are required to confirm the feasibility of this strategy.

  4. Chronotropic Modulation of the Source-Sink Relationship of Sinoatrial-Atrial Impulse Conduction and Its Significance to Initiation of AF: A One-Dimensional Model Study (United States)

    Cacciani, Francesca; Zaniboni, Massimiliano


    Initiation and maintenance of atrial fibrillation (AF) is often associated with pharmacologically or pathologically induced bradycardic states. Even drugs specifically developed in order to counteract cardiac arrhythmias often combine their action with bradycardia and, in turn, with development of AF, via still largely unknown mechanisms. This study aims to simulate action potential (AP) conduction between sinoatrial node (SAN) and atrial cells, either arranged in cell pairs or in a one-dimensional strand, where the relative amount of SAN membrane is made varying, in turn, with junctional resistance. The source-sink relationship between the two membrane types is studied in control conditions and under different simulated chronotropic interventions, in order to define a safety factor for pacemaker-to-atrial AP conduction (SASF) for each treatment. Whereas antiarrhythmic-like interventions which involve downregulation of calcium channels or of calcium handling decrease SASF, the simulation of Ivabradine administration does so to a lesser extent. Particularly interesting is the increase of SASF observed when downregulation GKr, which simulates the administration of class III antiarrhythmic agents and is likely sustained by an increase in ICaL. Also, the increase in SASF is accompanied by a decreased conduction delay and a better entrainment of repolarization, which is significant to anti-AF strategies. PMID:26229960

  5. Chronotropic Modulation of the Source-Sink Relationship of Sinoatrial-Atrial Impulse Conduction and Its Significance to Initiation of AF: A One-Dimensional Model Study

    Directory of Open Access Journals (Sweden)

    Francesca Cacciani


    Full Text Available Initiation and maintenance of atrial fibrillation (AF is often associated with pharmacologically or pathologically induced bradycardic states. Even drugs specifically developed in order to counteract cardiac arrhythmias often combine their action with bradycardia and, in turn, with development of AF, via still largely unknown mechanisms. This study aims to simulate action potential (AP conduction between sinoatrial node (SAN and atrial cells, either arranged in cell pairs or in a one-dimensional strand, where the relative amount of SAN membrane is made varying, in turn, with junctional resistance. The source-sink relationship between the two membrane types is studied in control conditions and under different simulated chronotropic interventions, in order to define a safety factor for pacemaker-to-atrial AP conduction (SASF for each treatment. Whereas antiarrhythmic-like interventions which involve downregulation of calcium channels or of calcium handling decrease SASF, the simulation of Ivabradine administration does so to a lesser extent. Particularly interesting is the increase of SASF observed when downregulation GKr, which simulates the administration of class III antiarrhythmic agents and is likely sustained by an increase in ICaL. Also, the increase in SASF is accompanied by a decreased conduction delay and a better entrainment of repolarization, which is significant to anti-AF strategies.

  6. Molecular modeling and simulation studies of recombinant laccase from Yersinia enterocolitica suggests significant role in the biotransformation of non-steroidal anti-inflammatory drugs. (United States)

    Singh, Deepti; Rawat, Surender; Waseem, Mohd; Gupta, Sunita; Lynn, Andrew; Nitin, Mukesh; Ramchiary, Nirala; Sharma, Krishna Kant


    The YacK gene from Yersinia enterocolitica strain 7, cloned in pET28a vector and expressed in Escherichia coli BL21 (DE3), showed laccase activity when oxidized with 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and guaiacol. The recombinant laccase protein was purified and characterized biochemically with a molecular mass of ≈58 KDa on SDS-PAGE and showed positive zymogram with ABTS. The protein was highly robust with optimum pH 9.0 and stable at 70 °C upto 12 h with residual activity of 70%. Kinetic constants, Km values, for ABTS and guaiacol were 675 μM and 2070 μM, respectively, with corresponding Vmax values of 0.125 μmol/ml/min and 6500 μmol/ml/min. It also possess antioxidative property against BSA and Cu(2+)/H2O2 model system. Constant pH MD simulation studies at different protonation states of the system showed ABTS to be most stable at acidic pH, whereas, diclofenac at neutral pH. Interestingly, aspirin drifted out of the binding pocket at acidic and neutral pH, but showed stable binding at alkaline pH. The biotransformation of diclofenac and aspirin by laccase also corroborated the in silico results. This is the first report on biotransformation of non-steroidal anti-inflammatory drugs (NSAIDs) using recombinant laccase from gut bacteria, supported by in silico simulation studies.

  7. Molecular modeling and simulation studies of recombinant laccase from Yersinia enterocolitica suggests significant role in the biotransformation of non-steroidal anti-inflammatory drugs

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Deepti; Rawat, Surender [Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana (India); Waseem, Mohd; Gupta, Sunita; Lynn, Andrew [School of Computational & Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Nitin, Mukesh; Ramchiary, Nirala [School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Sharma, Krishna Kant, E-mail: [Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana (India)


    The YacK gene from Yersinia enterocolitica strain 7, cloned in pET28a vector and expressed in Escherichia coli BL21 (DE3), showed laccase activity when oxidized with 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and guaiacol. The recombinant laccase protein was purified and characterized biochemically with a molecular mass of ≈58 KDa on SDS-PAGE and showed positive zymogram with ABTS. The protein was highly robust with optimum pH 9.0 and stable at 70 °C upto 12 h with residual activity of 70%. Kinetic constants, K{sub m} values, for ABTS and guaiacol were 675 μM and 2070 μM, respectively, with corresponding Vmax values of 0.125 μmol/ml/min and 6500 μmol/ml/min. It also possess antioxidative property against BSA and Cu{sup 2+}/H{sub 2}O{sub 2} model system. Constant pH MD simulation studies at different protonation states of the system showed ABTS to be most stable at acidic pH, whereas, diclofenac at neutral pH. Interestingly, aspirin drifted out of the binding pocket at acidic and neutral pH, but showed stable binding at alkaline pH. The biotransformation of diclofenac and aspirin by laccase also corroborated the in silico results. This is the first report on biotransformation of non-steroidal anti-inflammatory drugs (NSAIDs) using recombinant laccase from gut bacteria, supported by in silico simulation studies. - Highlights: • Laccase from Yersinia enterocolitica strain 7 was expressed in Escherichia coli BL21 (DE3). • Recombinant laccase was found to be thermostable and alkali tolerant. • The in silico and experimental studied proves the biotransformation of NSAIDs. • Laccase binds to ligands differentially under different protonation state. • Laccase also possesses free radical scavenging property.

  8. A Significant Play

    Institute of Scientific and Technical Information of China (English)

    梁海光; 陈明


    Yesterday evening, I went to see a play. It was really significant. It was about Zheng Xiaoyue, a very clever and diligent middle school student. Unfortunately, her mother died when she and her brother were very young. Her father was out of work and,

  9. Climatic significance of

    Institute of Scientific and Technical Information of China (English)

    QIAN; Junlong


    [1]Jiao Jiujiu, Grey hydrogeologic system analysis and time series model, Survey Science and Technology (in Chinese), 1987,(10): 39-43.[2]Li Shuwen, Wang Baolai, Xiao Guoqiang, A compound model of grey and periodic scrape and its application in groundwater prediction, Journal of Hebei Institute of Architectural Science & Technology (in Chinese), 1992, (3): 246-251.[3]Wang Qingyin, Li Shuwen, Grey distributed parameter model and groundwater analog, Journal of Hebei Institute of Architectural Science & Technology (in Chinese), 1992, (3): 66-70.[4]Guo Chunqing, Xia Riyuan, Liu Zhenglin, Gray Systematic Theory and Methodological Study of Krast Groundwater Resources Evaluation (in Chinese), Beijing: Geological Publishing House, 1993, 3-60.[5]Wang Qingyin, Liu Kaidi, The Mathematical Method of Grey Systematic Theory and Its Application (in Chinese), Chengdu: Publishing House of Southwestern China University of Communication, 1990, 23-27.[6]Wang Qingyin, Wu Heqing, The concept of grey number and its property, in Proceedings of NAFIPS98, USA, 1998,45-49.[7]Givoli, D., Doukhovni, I., Finite element programming approach for contact problems with geometrical nonlinearity, Computers and Structures, 1996, (8): 31-41.[8]Li Shuwen, Wang Zhiqiang, Wu Qiang, The superiority of storage-centered finite element method in solving seepage problem, Coal Geology and Exploration (in Chinese), 1999, (5): 46-49.

  10. Significant Tsunami Events (United States)

    Dunbar, P. K.; Furtney, M.; McLean, S. J.; Sweeney, A. D.


    Tsunamis have inflicted death and destruction on the coastlines of the world throughout history. The occurrence of tsunamis and the resulting effects have been collected and studied as far back as the second millennium B.C. The knowledge gained from cataloging and examining these events has led to significant changes in our understanding of tsunamis, tsunami sources, and methods to mitigate the effects of tsunamis. The most significant, not surprisingly, are often the most devastating, such as the 2011 Tohoku, Japan earthquake and tsunami. The goal of this poster is to give a brief overview of the occurrence of tsunamis and then focus specifically on several significant tsunamis. There are various criteria to determine the most significant tsunamis: the number of deaths, amount of damage, maximum runup height, had a major impact on tsunami science or policy, etc. As a result, descriptions will include some of the most costly (2011 Tohoku, Japan), the most deadly (2004 Sumatra, 1883 Krakatau), and the highest runup ever observed (1958 Lituya Bay, Alaska). The discovery of the Cascadia subduction zone as the source of the 1700 Japanese "Orphan" tsunami and a future tsunami threat to the U.S. northwest coast, contributed to the decision to form the U.S. National Tsunami Hazard Mitigation Program. The great Lisbon earthquake of 1755 marked the beginning of the modern era of seismology. Knowledge gained from the 1964 Alaska earthquake and tsunami helped confirm the theory of plate tectonics. The 1946 Alaska, 1952 Kuril Islands, 1960 Chile, 1964 Alaska, and the 2004 Banda Aceh, tsunamis all resulted in warning centers or systems being established.The data descriptions on this poster were extracted from NOAA's National Geophysical Data Center (NGDC) global historical tsunami database. Additional information about these tsunamis, as well as water level data can be found by accessing the NGDC website

  11. Significance evaluation in factor graphs

    DEFF Research Database (Denmark)

    Madsen, Tobias; Hobolth, Asger; Jensen, Jens Ledet


    Background Factor graphs provide a flexible and general framework for specifying probability distributions. They can capture a range of popular and recent models for analysis of both genomics data as well as data from other scientific fields. Owing to the ever larger data sets encountered...... in genomics and the multiple-testing issues accompanying them, accurate significance evaluation is of great importance. We here address the problem of evaluating statistical significance of observations from factor graph models. Results Two novel numerical approximations for evaluation of statistical....... Conclusions The applicability of saddlepoint approximation and importance sampling is demonstrated on known models in the factor graph framework. Using the two methods we can substantially improve computational cost without compromising accuracy. This contribution allows analyses of large datasets...

  12. A Significant Step Forward

    Institute of Scientific and Technical Information of China (English)


    Australia officially ratified the Kyoto Protocol on December 3,the first act of its new government under Prime Minister Kevin Rudd.Rudd signed the instrument of ratification the very day he was sworn in by Australia’s Governor General Michael Jeffery. This is a significant step in Australia’s efforts to fight climate change domestically and with the international community,Rudd said in a statement.The Australian Government will do everything in its power to help Australia meet its Kyoto obligations,he added.

  13. Anthropological significance of phenylketonuria. (United States)

    Saugstad, L F


    The highest incidence rates of phenylketonuria (PKU) have been observed in Ireland and Scotlant. Parents heterozygous for PKU in Norway differ significantly from the general population in the Rhesus, Kell and PGM systems. The parents investigated showed an excess of Rh negative, Kell plus and PGM type 1 individuals, which makes them similar to the present populations in Ireland and Scotlant. It is postulated that the heterozygotes for PKU in Norway are descended from a completely assimilated sub-population of Celtic origin, who came or were brought here, 1ooo years ago. Bronze objects of Western European (Scottish, Irish) origin, found in Viking graves widely distributed in Norway, have been taken as evidence of Vikings returning with loot (including a number of Celts) from Western Viking settlements. The continuity of residence since the Viking age in most habitable parts of Norway, and what seems to be a nearly complete regional relationship between the sites where Viking graves contain western imported objects and the birthplaces of grandparents of PKUs identified in Norway, lend further support to the hypothesis that the heterozygotes for PKU in Norway are descended from a completely assimilated subpopulation. The remarkable resemblance between Iceland and Ireland, in respect of several genetic markers (including the Rhesus, PGM and Kell systems), is considered to be an expression of a similar proportion of people of Celtic origin in each of the two countries. Their identical, high incidence rates of PKU are regarded as further evidence of this. The significant decline in the incidence of PKU when one passes from Ireland, Scotland and Iceland, to Denmark and on to Norway and Sweden, is therefore explained as being related to a reduction in the proportion of inhabitants of Celtic extraction in the respective populations.

  14. Assessing the Significance of Cohort and Period Effects in Hierarchical Age-Period-Cohort Models: Applications to Verbal Test Scores and Voter Turnout in U.S. Presidential Elections. (United States)

    Frenk, Steven M; Yang, Yang Claire; Land, Kenneth C


    In recently developed hierarchical age-period-cohort (HAPC) models, inferential questions arise: How can one assess or judge the significance of estimates of individual cohort and period effects in such models? And how does one assess the overall statistical significance of the cohort and/or the period effects? Beyond statistical significance is the question of substantive significance. This paper addresses these questions. In the context of empirical applications of linear and generalized linear mixed-model specifications of HAPC models using data on verbal test scores and voter turnout in U.S. presidential elections, respectively, we describe a two-step approach and a set of guidelines for assessing statistical significance. The guidelines include assessments of patterns of effects and statistical tests both for the effects of individual cohorts and time periods as well as for entire sets of cohorts and periods. The empirical applications show strong evidence that trends in verbal test scores are primarily cohort driven, while voter turnout is primarily a period phenomenon.

  15. Generalized PSF modeling for optimized quantitation in PET imaging (United States)

    Ashrafinia, Saeed; Mohy-ud-Din, Hassan; Karakatsanis, Nicolas A.; Jha, Abhinav K.; Casey, Michael E.; Kadrmas, Dan J.; Rahmim, Arman


    Point-spread function (PSF) modeling offers the ability to account for resolution degrading phenomena within the PET image generation framework. PSF modeling improves resolution and enhances contrast, but at the same time significantly alters image noise properties and induces edge overshoot effect. Thus, studying the effect of PSF modeling on quantitation task performance can be very important. Frameworks explored in the past involved a dichotomy of PSF versus no-PSF modeling. By contrast, the present work focuses on quantitative performance evaluation of standard uptake value (SUV) PET images, while incorporating a wide spectrum of PSF models, including those that under- and over-estimate the true PSF, for the potential of enhanced quantitation of SUVs. The developed framework first analytically models the true PSF, considering a range of resolution degradation phenomena (including photon non-collinearity, inter-crystal penetration and scattering) as present in data acquisitions with modern commercial PET systems. In the context of oncologic liver FDG PET imaging, we generated 200 noisy datasets per image-set (with clinically realistic noise levels) using an XCAT anthropomorphic phantom with liver tumours of varying sizes. These were subsequently reconstructed using the OS-EM algorithm with varying PSF modelled kernels. We focused on quantitation of both SUVmean and SUVmax, including assessment of contrast recovery coefficients, as well as noise-bias characteristics (including both image roughness and coefficient of-variability), for different tumours/iterations/PSF kernels. It was observed that overestimated PSF yielded more accurate contrast recovery for a range of tumours, and typically improved quantitative performance. For a clinically reasonable number of iterations, edge enhancement due to PSF modeling (especially due to over-estimated PSF) was in fact seen to lower SUVmean bias in small tumours. Overall, the results indicate that exactly matched PSF

  16. Statistically significant relational data mining :

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Jonathan W.; Leung, Vitus Joseph; Phillips, Cynthia Ann; Pinar, Ali; Robinson, David Gerald; Berger-Wolf, Tanya; Bhowmick, Sanjukta; Casleton, Emily; Kaiser, Mark; Nordman, Daniel J.; Wilson, Alyson G.


    This report summarizes the work performed under the project (3z(BStatitically significant relational data mining.(3y (BThe goal of the project was to add more statistical rigor to the fairly ad hoc area of data mining on graphs. Our goal was to develop better algorithms and better ways to evaluate algorithm quality. We concetrated on algorithms for community detection, approximate pattern matching, and graph similarity measures. Approximate pattern matching involves finding an instance of a relatively small pattern, expressed with tolerance, in a large graph of data observed with uncertainty. This report gathers the abstracts and references for the eight refereed publications that have appeared as part of this work. We then archive three pieces of research that have not yet been published. The first is theoretical and experimental evidence that a popular statistical measure for comparison of community assignments favors over-resolved communities over approximations to a ground truth. The second are statistically motivated methods for measuring the quality of an approximate match of a small pattern in a large graph. The third is a new probabilistic random graph model. Statisticians favor these models for graph analysis. The new local structure graph model overcomes some of the issues with popular models such as exponential random graph models and latent variable models.

  17. miR-155, identified as anti-metastatic by global miRNA profiling of a metastasis model, inhibits cancer cell extravasation and colonization in vivo and causes significant signaling alterations

    DEFF Research Database (Denmark)

    Gravgaard, Karina Hedelund; Terp, Mikkel G; Lund, Rikke R


    To gain insight into miRNA regulation in metastasis formation, we used a metastasis cell line model that allows investigation of extravasation and colonization of circulating cancer cells to lungs in mice. Using global miRNA profiling, 28 miRNAs were found to exhibit significantly altered express...

  18. Over-estimation of glomerular filtration rate by single injection [51Cr]EDTA plasma clearance determination in patients with ascites

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Brøchner-Mortensen, J; Malchow-Møller, A;


    The total plasma (Clt) and the renal plasma (Clr) clearances of [51Cr]EDTA were determined simultaneously in nine patients with ascites due to liver cirrhosis. Clt (mean 78 ml/min, range 34-115 ml/min) was significantly higher than Clr (mean 52 ml/min, range 13-96 ml/min, P .... To assess glomerular filtration rate in presence of ascites, the renal plasma clearance of [51Cr]EDTA should be used instead of the total plasma clearance....

  19. Time esophageal pH < 4 overestimates the prevalence of pathologic esophageal reflux in subjects with gastroesophageal reflux disease treated with proton pump inhibitors

    Directory of Open Access Journals (Sweden)

    Sloan Sheldon


    Full Text Available Abstract Background A Stanford University study reported that in asymptomatic GERD patients who were being treated with a proton pump inhibitor (PPI, 50% had pathologic esophageal acid exposure. Aim We considered the possibility that the high prevalence of pathologic esophageal reflux might simply have resulted from calculating acidity as time pH Methods We calculated integrated acidity and time pH Results The prevalence of pathologic 24-hour esophageal reflux in both studies was significantly higher when measured as time pH Conclusion In GERD subjects treated with a PPI, measuring time esophageal pH

  20. Explaining global increases in water use efficiency: why have we overestimated responses to rising atmospheric CO(2 in natural forest ecosystems?

    Directory of Open Access Journals (Sweden)

    Lucas C R Silva

    Full Text Available BACKGROUND: The analysis of tree-ring carbon isotope composition (δ(13C has been widely used to estimate spatio-temporal variations in intrinsic water use efficiency (iWUE of tree species. Numerous studies have reported widespread increases in iWUE coinciding with rising atmospheric CO(2 over the past century. While this could represent a coherent global response, the fact that increases of similar magnitude were observed across biomes with no apparent effect on tree growth raises the question of whether iWUE calculations reflect actual physiological responses to elevated CO(2 levels. METHODOLOGY/RESULTS: Here we use Monte Carlo simulations to test if an artifact of calculation could explain observed increases in iWUE. We show that highly significant positive relationships between iWUE and CO(2 occur even when simulated data (randomized δ(13C values spanning the observed range are used in place of actual tree-ring δ(13C measurements. From simulated data sets we calculated non-physiological changes in iWUE from 1900 to present and across a 4000 m altitudinal range. This generated results strikingly similar to those reported in recent studies encompassing 22 species from tropical, subtropical, temperate, boreal and mediterranean ecosystems. Only 6 of 49 surveyed case studies showed increases in iWUE significantly higher than predicted from random values. CONCLUSIONS/SIGNIFICANCE: Our results reveal that increases in iWUE estimated from tree-ring δ(13C occur independently of changes in (13C discrimination that characterize physiological responses to elevated CO(2. Due to a correlation with CO(2 concentration, which is used as an independent factor in the iWUE calculation, any tree-ring δ(13C data set would inevitably generate increasing iWUE over time. Therefore, although consistent, previously reported trends in iWUE do not necessarily reflect a coherent global response to rising atmospheric CO(2. We discuss the significance of these findings

  1. Pathophysiological significance of the two-pore domain K+ channel K2P5.1 in splenic CD4+CD25− T cell subset from a chemically-induced murine inflammatory bowel disease model (United States)

    Nakakura, Sawa; Matsui, Miki; Sato, Aya; Ishii, Mizuki; Endo, Kyoko; Muragishi, Sayaka; Murase, Miki; Kito, Hiroaki; Niguma, Hiroki; Kurokawa, Natsumi; Fujii, Masanori; Araki, Masatake; Araki, Kimi; Ohya, Susumu


    The alkaline pH-activated, two-pore domain K+ channel K2P5.1 (also known as TASK2/KCNK5) plays an important role in maintaining the resting membrane potential, and contributes to the control of Ca2+ signaling in several types of cells. Recent studies highlighted the potential role of the K2P5.1 K+ channel in the pathogenesis of autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. The aim of the present study was to elucidate the pathological significance of the K2P5.1 K+ channel in inflammatory bowel disease (IBD). The degrees of colitis, colonic epithelial damage, and colonic inflammation were quantified in the dextran sulfate sodium-induced mouse IBD model by macroscopic and histological scoring systems. The expression and functional activity of K2P5.1 in splenic CD4+ T cells were measured using real-time PCR, Western blot, and fluorescence imaging assays. A significant increase was observed in the expression of K2P5.1 in the splenic CD4+ T cells of the IBD model. Concomitant with this increase, the hyperpolarization response induced by extracellular alkaline pH was significantly larger in the IBD model with the corresponding intracellular Ca2+ rises. The expression of K2P5.1 was higher in CD4+CD25− T cells than in CD4+CD25+ regulatory T cells. The knockout of K2P5.1 in mice significantly suppressed the disease responses implicated in the IBD model. Alternations in intracellular Ca2+ signaling following the dysregulated expression of K2P5.1 were associated with the disease pathogenesis of IBD. The results of the present study suggest that the K2P5.1 K+ channel in CD4+CD25− T cell subset is a potential therapeutic target and biomarker for IBD. PMID:26578971

  2. Mechanisms controlling primary and new production in a global ecosystem model – Part II: the role of the upper ocean short-term periodic and episodic mixing events

    Directory of Open Access Journals (Sweden)

    E. E. Popova


    Full Text Available The use of 6 h, daily, weekly and monthly atmospheric forcing resulted in dramatically different predictions of plankton productivity in a global 3-D coupled physical-biogeochemical model.

    Resolving the diurnal cycle of atmospheric variability by use of 6 h forcing, and hence also diurnal variability in UML depth, produced the largest difference, reducing predicted global primary and new production by 25% and 10% respectively relative to that predicted with daily and weekly forcing. This decrease varied regionally, being a 30% reduction in equatorial areas and 25% at moderate and high latitudes. A 10% increase in the primary production was seen in the peripheries of the oligotrophic gyres.

    By resolving the diurnal cycle, model performance was significantly improved with respect to several common problems: underestimated primary production in the oligotrophic gyres; overestimated primary production in the Southern Ocean; overestimated magnitude of the spring bloom in the subarctic Pacific Ocean, and overestimated primary production in equatorial areas. The result of using 6 h forcing on predicted ecosystem dynamics was profound, the effects persisting far beyond the hourly timescale, and having major consequences for predicted global and new production on an annual basis.

  3. Electrical Conductivity Beneath the Andean Back-arc in Argentina Near 36.5°S: Creation of Minimum Structure 2D Model Across EW Transect Based on Significantly 3D Data (United States)

    Burd, A.; Booker, J.; Favetto, A.; Pomposiello, M.; Giordanengo, G.; Larsen, J. C.


    S. Mendoza Province, south of the Nazca flat slab, has widespread recent basaltic volcanism, but no historic activity. Over the last 1 MY, the basalt has evolved from having a slab signature to OIB. In early 2005, we collected 18 MT sites from 67 to 70°W along 36.7°S, near the large caldera Payún Matrú. Significantly 3D data cause difficulty identifying regional strike and performing minimum structure 2D inversions. Use of phase tensors and induction vectors allow identification of possible regional strikes. Various starting models for the minimum structure inversion allow comparison of effect of different regional strikes on the resulting electrical conductivity models. Preliminary analysis of a piecewise-2D region at the center of the profile suggests the west end of the profile to contain lower crustal to upper mantle conductivity which decreases and deepens to the east.

  4. True Public Access Defibrillator Coverage is Overestimated

    NARCIS (Netherlands)

    Sun, Christopher L.F.; Demirtas, Derya; Brooks, Steven C.; Morrison, Laurie J.; Chan, Timothy C.Y.


    Background: Out-of-hospital cardiac arrests (OHCAs) occur at all times of the day and night. Immediate access to an AED increases survival. However, most public-location AEDs are placed in buildings without 24 hour access. Objective: To measure fixed-location public AED coverage of OHCAs by time

  5. In Vivo Imaging Reveals Significant Tumor Vascular Dysfunction and Increased Tumor Hypoxia-Inducible Factor-1α Expression Induced by High Single-Dose Irradiation in a Pancreatic Tumor Model. (United States)

    Maeda, Azusa; Chen, Yonghong; Bu, Jiachuan; Mujcic, Hilda; Wouters, Bradly G; DaCosta, Ralph S


    To investigate the effect of high-dose irradiation on pancreatic tumor vasculature and microenvironment using in vivo imaging techniques. A BxPC3 pancreatic tumor xenograft was established in a dorsal skinfold window chamber model and a subcutaneous hind leg model. Tumors were irradiated with a single dose of 4, 12, or 24 Gy. The dorsal skinfold window chamber model was used to assess tumor response, vascular function and permeability, platelet and leukocyte adhesion to the vascular endothelium, and tumor hypoxia for up to 14 days after 24-Gy irradiation. The hind leg model was used to monitor tumor size, hypoxia, and vascularity for up to 65 days after 24-Gy irradiation. Tumors were assessed histologically to validate in vivo observations. In vivo fluorescence imaging revealed temporary vascular dysfunction in tumors irradiated with a single dose of 4 to 24 Gy, but most significantly with a single dose of 24 Gy. Vascular functional recovery was observed by 14 days after irradiation in a dose-dependent manner. Furthermore, irradiation with 24 Gy caused platelet and leukocyte adhesion to the vascular endothelium within hours to days after irradiation. Vascular permeability was significantly higher in irradiated tumors compared with nonirradiated controls 14 days after irradiation. This observation corresponded with increased expression of hypoxia-inducible factor-1α in irradiated tumors. In the hind leg model, irradiation with a single dose of 24 Gy led to tumor growth delay, followed by tumor regrowth. Irradiation of the BxPC3 tumors with a single dose of 24 Gy caused transient vascular dysfunction and increased expression of hypoxia-inducible factor-1α. Such biological changes may impact tumor response to high single-dose and hypofractionated irradiation, and further investigations are needed to better understand the clinical outcomes of stereotactic body radiation therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. VALORA: data base system for storage significant information used in the behavior modelling in the biosphere; VALORA: sistema de base de datos para almacenar informacion significativa utilizada en la modelizacion del comportamiento en la biosfera

    Energy Technology Data Exchange (ETDEWEB)

    Valdes R, M. [CPHR, Calle 20, No. 4113 e/41 y 47, Playa, La Habana 11300 (Cuba); Aguero P, A.; Perez S, D.; Cancio P, D. [CIEMAT, Av. Complutense No. 22, 28040 Madrid (Spain)]. e-mail:


    The nuclear and radioactive facilities can emit to the environment effluents that contain radionuclides, which are dispersed and/or its accumulate in the atmosphere, the terrestrial surface and the surface waters. As part of the evaluations of radiological impact, it requires to be carried out qualitative and quantitative analysis. In many of the cases it doesn't have the real values of the parameters that are used in the modelling, neither it is possible to carry out their measure, for that to be able to carry out the evaluation it needs to be carried out an extensive search of that published in the literature about the possible values of each parameter, under similar conditions to the object of study, this work can be extensive. In this work the characteristics of the VALORA Database System developed with the purpose of organizing and to automate significant information that it appears in different sources (scientific or technique literature) of the parameters that are used in the modelling of the behavior of the pollutants in the environment and the values assigned to these parameters that are used in the evaluation of the radiological impact potential is described; VALORA allows the consultation and selection of the characteristic parametric data of different situations and processes that are required by the calculation pattern implemented. The software VALORA it is a component of a group of tools computer that have as objective to help to the resolution of dispersion models and transfer of pollutants. (Author)

  7. Flight assessment of the onboard propulsion system model for the Performance Seeking Control algorithm on an F-15 aircraft (United States)

    Orme, John S.; Schkolnik, Gerard S.


    Performance Seeking Control (PSC), an onboard, adaptive, real-time optimization algorithm, relies upon an onboard propulsion system model. Flight results illustrated propulsion system performance improvements as calculated by the model. These improvements were subject to uncertainty arising from modeling error. Thus to quantify uncertainty in the PSC performance improvements, modeling accuracy must be assessed. A flight test approach to verify PSC-predicted increases in thrust (FNP) and absolute levels of fan stall margin is developed and applied to flight test data. Application of the excess thrust technique shows that increases of FNP agree to within 3 percent of full-scale measurements for most conditions. Accuracy to these levels is significant because uncertainty bands may now be applied to the performance improvements provided by PSC. Assessment of PSC fan stall margin modeling accuracy was completed with analysis of in-flight stall tests. Results indicate that the model overestimates the stall margin by between 5 to 10 percent. Because PSC achieves performance gains by using available stall margin, this overestimation may represent performance improvements to be recovered with increased modeling accuracy. Assessment of thrust and stall margin modeling accuracy provides a critical piece for a comprehensive understanding of PSC's capabilities and limitations.

  8. A void coalescence model for combined tension and shear (United States)

    Butcher, C.; Chen, Z. T.


    The influence of shear loading on damage development in Gurson-based models has long been neglected resulting in inadequate fracture strain predictions at low triaxiality where shear effects become significant. The plastic limit-load fracture criterion used in advanced Gurson models neglects the influence of shear loading and overestimates the fracture strain and porosity at low triaxiality. In this paper, we extend the recently proposed shear damage model of Xue [1] to provide a stronger physical foundation by removing the simplifying assumptions. Then we directly modify the plastic limit-load fracture criterion by coupling with the extended shear damage model to account for shear weakening and failure of the intervoid ligament in void coalescence. We apply the modified plastic limit-load criterion to predict the necking of sheet tensile specimens and find very good agreement with the available experimental results.

  9. Monoclonal gammopathy of undetermined significance

    National Research Council Canada - National Science Library

    Kyle, Robert A; Vincent Rajkumar, S


    Summary Significant advances have been made in our understanding of the natural history, pathogenesis, mechanisms of progression and prognosis of monoclonal gammopathy of undetermined significance (MGUS...

  10. A phytosterol enriched refined extract of Brassica campestris L. pollen significantly improves benign prostatic hyperplasia (BPH) in a rat model as compared to the classical TCM pollen preparation Qianlie Kang Pule'an Tablets. (United States)

    Wang, Ruwei; Kobayashi, Yuta; Lin, Yu; Rauwald, Hans Wilhelm; Fang, Ling; Qiao, Hongxiang; Kuchta, Kenny


    In Qinghai Province, the Brassica campestris L. pollen preparation Qianlie Kang Pule'an Tablet (QKPT) is traditionally used for BPH therapy. However, in QKPT the content of supposedly active phytosterols is relatively low at 2.59%, necessitating high doses for successful therapy. Therefore, a phytosterol enriched (4.54%) refined extract of B. campestris pollen (PE) was developed and compared with QKPT in a BPH rat model. Six groups of rats (n=8 each), namely sham-operated distilled water control, castrated distilled water control, castrated QKPT 2.0g/kg, castrated PE 0.1g/kg, castrated PE 0.2g/kg, and castrated PE 0.4g/kg, were intragastrically treated with the respective daily doses. Testosterone propionate (0.3mg/day) was administered to all castrated rats, while the sham-operated group received placebo injections. After 30 days, the animals were sacrificed and prostates as well as seminal vesicles excised and weighted in order to calculate prostate volume index (PVI) as well as prostate index (PI) and seminal vesicle index (SVI), defined as organ weight in g per 100g body weight. Compared with sham-operated controls, PI (p<0.01), PVI (p<0.01), and SVI (p<0.01) were all significantly increased in all castrated, testosterone treated rats. After treatment with PE at 0.4 and 0.2g/kg or QKPT at 2.0g/kg per day, both indices were significantly reduced (p<0.01) as compared to the castrated distilled water control. For PE at 0.1g/kg per day only PI was significantly reduced (p<0.05). At the highest PE concentration of 0.4g/kg per day both PI and SVI were also significantly reduced when compared to the QKPT group (p<0.05). Both PE and QKPT demonstrated curative effects against BPH in the applied animal model. In its highest dose at 0.4g/kg per day, PE was clearly superior to QKPT.

  11. Near infra-red photoimmunotherapy with anti-CEA-IR700 results in extensive tumor lysis and a significant decrease in tumor burden in orthotopic mouse models of pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Ali A Maawy

    Full Text Available Photoimmunotherapy (PIT of cancer utilizes tumor-specific monoclonal antibodies conjugated to a photosensitizer phthalocyanine dye IR700 which becomes cytotoxic upon irradiation with near infrared light. In this study, we aimed to evaluate the efficacy of PIT on human pancreatic cancer cells in vitro and in vivo in an orthotopic nude mouse model. The binding capacity of anti-CEA antibody to BxPC-3 human pancreatic cancer cells was determined by FACS analysis. An in vitro cytotoxicity assay was used to determine cell death following treatment with PIT. For in vivo determination of PIT efficacy, nude mice were orthotopically implanted with BxPC-3 pancreatic tumors expressing green fluorescent protein (GFP. After tumor engraftment, the mice were divided into two groups: (1 treatment with anti-CEA-IR700 + 690 nm laser and (2 treatment with 690 nm laser only. Anti-CEA-IR700 (100 μg was administered to group (1 via tail vein injection 24 hours prior to therapy. Tumors were then surgically exposed and treated with phototherapy at an intensity of 150 mW/cm2 for 30 minutes. Whole body imaging was done subsequently for 5 weeks using an OV-100 small animal imaging system. Anti-CEA-IR700 antibody bound to the BxPC3 cells to a high degree as shown by FACS analysis. Anti-CEA-IR700 caused extensive cancer cell killing after light activation compared to control cells in cytotoxicity assays. In the orthotopic models of pancreatic cancer, the anti-CEA-IR700 group had significantly smaller tumors than the control after 5 weeks (p<0.001. There was no significant difference in the body weights of mice in the anti-CEA-IR700 and control groups indicating that PIT was well tolerated by the mice.

  12. AGN-2979, an inhibitor of tryptophan hydroxylase activation, does not affect serotonin synthesis in Flinders Sensitive Line rats, a rat model of depression, but produces a significant effect in Flinders Resistant Line rats. (United States)

    Kanemaru, Kazuya; Nishi, Kyoko; Diksic, Mirko


    The neurotransmitter, serotonin, is involved in several brain functions, including both normal, physiological functions, and pathophysiological functions. Alterations in any of the normal parameters of serotonergic neurotransmission can produce several different psychiatric disorders, including major depression. In many instances, brain neurochemical variables are not able to be studied properly in humans, thus making the use of good animal models extremely valuable. One of these animal models is the Flinders Sensitive Line (FSL) of rats, which has face, predictive and constructive validities in relation to human depression. The objective of this study was to quantify the effect of the tryptophan hydroxylase (TPH) activation inhibitor, AGN-2979, on the FSL rats (rats with depression-like behaviour), and compare it to the effect on the Flinders Resistant Line (FRL) of rats used as the control rats. The effect was evaluated by measuring changes in regional serotonin synthesis in the vehicle treated rats (FSL-VEH and FRL-VEH) relative to those measured in the AGN-2979 treated rats (FSL-AGN and FRL-AGN). Regional serotonin synthesis was measured autoradiographically in more than 30 brain regions. The measurements were performed using alpha-[(14)C]methyl-l-tryptophan as the tracer. The results indicate that AGN-2979 did not produce a significant reduction of TPH activity in the AGN-2979 group relative to the vehicle group (a reduction would have been observed if there had been an activation of TPH by the experimental setup) in the FSL rats. On the other hand, there was a highly significant reduction of synthesis in the FRL rats treated by AGN-2979, relative to the vehicle group. Together, the results demonstrate that in the FSL rats, AGN-2979 does not affect serotonin synthesis. This suggests that there was no activation of TPH in the FSL rats during the experimental procedure, but such activation did occur in the FRL rats. Because of this finding, it could be

  13. Entropy rates of low-significance bits sampled from chaotic physical systems (United States)

    Corron, Ned J.; Cooper, Roy M.; Blakely, Jonathan N.


    We examine the entropy of low-significance bits in analog-to-digital measurements of chaotic dynamical systems. We find the partition of measurement space corresponding to low-significance bits has a corrugated structure. Using simulated measurements of a map and experimental data from a circuit, we identify two consequences of this corrugated partition. First, entropy rates for sequences of low-significance bits more closely approach the metric entropy of the chaotic system, because the corrugated partition better approximates a generating partition. Second, accurate estimation of the entropy rate using low-significance bits requires long block lengths as the corrugated partition introduces more long-term correlation, and using only short block lengths overestimates the entropy rate. This second phenomenon may explain recent reports of experimental systems producing binary sequences that pass statistical tests of randomness at rates that may be significantly beyond the metric entropy rate of the physical source.

  14. A Differentiated Program: Significant Curriculum Adaptations. (United States)

    Alonso, Juan A.


    This article describes a model for curricular adaptations for gifted students. A distinction is made between non-significant curriculum adaptations that can be easily made by the regular teacher and significant curriculum adaptations that involve deep changes in aims, content, and evaluation criteria. (Contains references.) (DB)

  15. Bioenergetic and pharmacokinetic model for exposure of common loon (Gavia immer) chicks to methylmercury (United States)

    Karasov, W.H.; Kenow, K.P.; Meyer, M.W.; Fournier, F.


    A bioenergetics model was used to predict food intake of common loon (Gavia immer) chicks as a function of body mass during development, and a pharmacokinetics model, based on first-order kinetics in a single compartment, was used to predict blood Hg level as a function of food intake rate, food Hg content, body mass, and Hg absorption and elimination. Predictions were tested in captive growing chicks fed trout (Salmo gairdneri) with average MeHg concentrations of 0.02 (control), 0.4, and 1.2 ??g/g wet mass (delivered as CH3HgCl). Predicted food intake matched observed intake through 50 d of age but then exceeded observed intake by an amount that grew progressively larger with age, reaching a significant overestimate of 28% by the end of the trial. Respiration in older, nongrowing birds probably was overestimated by using rates measured in younger, growing birds. Close agreement was found between simulations and measured blood Hg, which varied significantly with dietary Hg and age. Although chicks may hatch with different blood Hg levels, their blood level is determined mainly by dietary Hg level beyond approximately two weeks of age. The model also may be useful for predicting Hg levels in adults and in the eggs that they lay, but its accuracy in both chicks and adults needs to be tested in free-living birds. ?? 2007 SETAC.

  16. Recent Developments in the Radiation Belt Environment Model (United States)

    Fok, M.-C.; Glocer, A.; Zheng, Q.; Horne, R. B.; Meredith, N. P.; Albert, J. M.; Nagai, T.


    The fluxes of energetic particles in the radiation belts are found to be strongly controlled by the solar wind conditions. In order to understand and predict the radiation particle intensities, we have developed a physics-based Radiation Belt Environment (RBE) model that considers the influences from the solar wind, ring current and plasmasphere. Recently, an improved calculation of wave-particle interactions has been incorporated. In particular, the model now includes cross diffusion in energy and pitch-angle. We find that the exclusion of cross diffusion could cause significant overestimation of electron flux enhancement during storm recovery. The RBE model is also connected to MHD fields so that the response of the radiation belts to fast variations in the global magnetosphere can be studied.Weare able to reproduce the rapid flux increase during a substorm dipolarization on 4 September 2008. The timing is much shorter than the time scale of wave associated acceleration.

  17. CNX-012-570, a direct AMPK activator provides strong glycemic and lipid control along with significant reduction in body weight; studies from both diet-induced obese mice and db/db mice models. (United States)

    Anil, Tharappel M; Harish, Chandrashekaran; Lakshmi, Mudigere N; Harsha, Krishnareddy; Onkaramurthy, Mallappa; Sathish Kumar, Venkatesh; Shree, Nitya; Geetha, Venkatachalaiah; Balamurali, Gundalmandikal V; Gopala, Aralakuppe S; Madhusudhan Reddy, Bobbili; Govind, Madabosse K; Anup, Mammen O; Moolemath, Yoganand; Venkataranganna, Marikunte V; Jagannath, Madanahalli R; Somesh, Baggavalli P


    AMP activated protein kinase (AMPK) regulates the coordination of anabolic and catabolic processes and is an attractive therapeutic target for T2DM, obesity and metabolic syndrome. We report the anti-hyperglycemic and anti-hyperlipidemic effects of CNX-012-570 is an orally bioavailable small molecule (molecular weight of 530 Daltons) that directly activates AMPK in DIO and db/db animal models of diabetes. Activity and efficacy of the compound was tested in cell based as well as cell free systems in vitro. Male C57BL/6 mice fed with high fat diet (HFD) were assigned to either vehicle or CNX-012-570 (3 mg/kg, orally once a day) for 8 weeks (n = 8). Genetically diabetic db/db mice on chow diet were dosed with vehicle control or CNX-012-570 (2.5 mg/kg, orally once a day) for 6 weeks (n = 8). CNX-012-570 is a highly potent and orally bioavailable compound activating AMPK in both cell and cell free systems. It inhibits lipolysis (33%) and gluconeogenesis (28%) in 3T3L1 cells and rat primary hepatocytes respectively. The efficacy of the molecule was translated to both DIO and db/db animal models of diabetes. CNX-012-570 has reduced fasting blood glucose levels by 14%, body weight by 24% and fasting serum triglycerides (TG) by 24%. CNX-012-570 showed a 22% reduction in fed serum cholesterol levels and 19% increase in HDL levels.In db/db mice model, CNX-012-570 has shown 18% decrease in fed glucose and 32% decrease in fasting glucose with a 2.57% reduction in absolute HbA1c. Decrease in serum insulin and glucose AUC indicates the increased insulin sensitivity. Body weight was reduced by 13% with increased browning of adipose tissue and decreased inguinal and mesenteric fat mass. There was significant reduction in liver TG and liver total cholesterol. CNX-012-570 has the potential to control hyperglycemia and hyperlipidemia. It also reduces body weight gain with an additional benefit of minimizing cardiovascular risks in diabetics.

  18. Significance Tests for Periodogram Peaks

    CERN Document Server

    Frescura, F A M; Frank, B S


    We discuss methods currently in use for determining the significance of peaks in the periodograms of time series. We discuss some general methods for constructing significance tests, false alarm probability functions, and the role played in these by independent random variables and by empirical and theoretical cumulative distribution functions. We also discuss the concept of "independent frequencies" in periodogram analysis. We propose a practical method for estimating the significance of periodogram peaks, applicable to all time series irrespective of the spacing of the data. This method, based on Monte Carlo simulations, produces significance tests that are tailor-made for any given astronomical time series.

  19. Accounting for the Impact of Impermeable Soil Layers on Pesticide Runoff and Leaching in a Landscape Vulnerability Model (United States)

    A regional-scale model that estimates landscape vulnerability of pesticide leaching and runoff (solution and particle adsorbed) underestimated runoff vulnerability and overestimated leaching vulnerability compared to measured data when applied to a gently rolling landscape in northeast Missouri. Man...

  20. Forecasting the mortality rates using Lee-Carter model and Heligman-Pollard model (United States)

    Ibrahim, R. I.; Ngataman, N.; Abrisam, W. N. A. Wan Mohd


    Improvement in life expectancies has driven further declines in mortality. The sustained reduction in mortality rates and its systematic underestimation has been attracting the significant interest of researchers in recent years because of its potential impact on population size and structure, social security systems, and (from an actuarial perspective) the life insurance and pensions industry worldwide. Among all forecasting methods, the Lee-Carter model has been widely accepted by the actuarial community and Heligman-Pollard model has been widely used by researchers in modelling and forecasting future mortality. Therefore, this paper only focuses on Lee-Carter model and Heligman-Pollard model. The main objective of this paper is to investigate how accurately these two models will perform using Malaysian data. Since these models involves nonlinear equations that are explicitly difficult to solve, the Matrix Laboratory Version 8.0 (MATLAB 8.0) software will be used to estimate the parameters of the models. Autoregressive Integrated Moving Average (ARIMA) procedure is applied to acquire the forecasted parameters for both models as the forecasted mortality rates are obtained by using all the values of forecasted parameters. To investigate the accuracy of the estimation, the forecasted results will be compared against actual data of mortality rates. The results indicate that both models provide better results for male population. However, for the elderly female population, Heligman-Pollard model seems to underestimate to the mortality rates while Lee-Carter model seems to overestimate to the mortality rates.

  1. On the Nonlinear Structural Analysis of Wind Turbine Blades using Reduced Degree-of-Freedom Models

    DEFF Research Database (Denmark)

    Holm-Jørgensen, Kristian; Larsen, Jesper Winther; Nielsen, Søren R.K.


    , modelling geometrical and inertial nonlinear couplings in the fundamental flap and edge direction. The purpose of this article is to examine the applicability of such a reduced-degree-of-freedom model in predicting the nonlinear response and stability of a blade by comparison to a full model based...... on a nonlinear co-rotating FE formulation. By use of the reduced-degree-of-freedom model it is shown that under strong resonance excitation of the fundamental flap or edge modes, significant energy is transferred to higher modes due to parametric or nonlinear coupling terms, which influence the response...... representing the case of infinitely many included modes, is shown to predict stable and ordered response for all considered parameters. Further, the analysis shows that the reduced-degree-of-freedom model of relatively low order overestimates the response near resonance peaks, which is a consequence...

  2. A non-grey analytical model for irradiated atmospheres. I: Derivation

    CERN Document Server

    Parmentier, Vivien


    Context. Semi-grey atmospheric models (with one opacity for the visible and one opacity for the infrared) are useful to understand the global structure of irradiated atmospheres, their dynamics and the interior structure and evolution of planets, brown dwarfs and stars. But when compared to direct numerical radiative transfer calculations for irradiated exoplanets, these models systematically overestimate the temperatures at low optical depth, independently of the opacity parameters. We wish to understand why semi-grey models fail at low optical depths, and provide a more accurate approximation to the atmospheric structure by accounting for the variable opacity in the infrared. Our analytical irradiated non-grey model is found to provide a range of temperatures that is consistent with that obtained by numerical calculations. We find that even for slightly non-grey thermal opacities the temperature structure differs significantly from previous semi-grey models. For small values of beta (expected when lines are...

  3. 植物光响应修正模型中系数的生物学意义研究%Study on biological significance of coefficients in modified model of photosynthesis-irradiance

    Institute of Scientific and Technical Information of China (English)

    叶子飘; 康华靖


    A modified model of photosynthesis-irradiance was used widely in investigating photosynthetic characteristics of plants. However, the biological significances of two coefficients in the modified model were unclear. It showed that two coefficients were considered as photo-inhibition and photo-saturation term, respectively. Through dimension analysis, their biological significances were the product of cross section of photosynthetic pigment in PSI1 for quantum absorption and average life of photosynthetic pigment in the excited state for photo-inhition and photo-saturation term in the modified model of photosynthesis-irradiance. That light absorption cross sections was less and the average lifetimes of photosynthetic pigment in the excited state were longer would not be useful to light energy absorption. On the contrary, that light absorption cross sections was greater and the average lifetimes of photosynthetic pigment in the excited state were shorter would be useful to light energy absorption. Investigations showed that plants were easily photo-inhibited if photo-inhibition and photo-saturation term are large.%植物光合作用对光响应修正模型被广泛应用于植物光合特性的研究,但该模型中系数的生物学意义不清楚.通过分析,认为植物光响应修正模型中系数分别为光抑制项和光饱和项.通过量纲分析,植物光响应修正模型中光抑制项和光饱和项的生物学意义是光系统Ⅱ天线色素分子光量子吸收截面与其处于激发态平均寿命的乘积.光系统Ⅱ天线色素分子处于激发态的平均寿命较长且光量子吸收截面较小,则不利于光量子的吸收;如果光系统Ⅱ天线色素分子的光量子吸收截面较大且其激发态的平均寿命较短,则有利于光量子的吸收.研究结果表明:如果光饱和项系数大且光抑制项系数也大,则植物越容易受抑制;如果光饱和项系数小且光抑制项系数也小,则植物越不容易发生光抑制.

  4. Significant Scales in Community Structure

    CERN Document Server

    Traag, V A; Van Dooren, P


    Many complex networks show signs of modular structure, uncovered by community detection. Although many methods succeed in revealing various partitions, it remains difficult to detect at what scale some partition is significant. This problem shows foremost in multi-resolution methods. We here introduce an efficient method for scanning for resolutions in one such method. Additionally, we introduce the notion of "significance" of a partition, based on subgraph probabilities. Significance is independent of the exact method used, so could also be applied in other methods, and can be interpreted as the gain in encoding a graph by making use of a partition. Using significance, we can determine "good" resolution parameters, which we demonstrate on benchmark networks. Moreover, optimizing significance itself also shows excellent performance. We demonstrate our method on voting data from the European Parliament. Our analysis suggests the European Parliament has become increasingly ideologically divided and that nationa...

  5. Spatial averaging infiltration model for layered soil

    Institute of Scientific and Technical Information of China (English)

    HU HePing; YANG ZhiYong; TIAN FuQiang


    To quantify the influences of soil heterogeneity on infiltration, a spatial averaging infiltration model for layered soil (SAI model) is developed by coupling the spatial averaging approach proposed by Chen et al. and the Generalized Green-Ampt model proposed by Jia et al. In the SAI model, the spatial heterogeneity along the horizontal direction is described by a probability distribution function, while that along the vertical direction is represented by the layered soils. The SAI model is tested on a typical soil using Monte Carlo simulations as the base model. The results show that the SAI model can directly incorporate the influence of spatial heterogeneity on infiltration on the macro scale. It is also found that the homogeneous assumption of soil hydraulic conductivity along the horizontal direction will overestimate the infiltration rate, while that along the vertical direction will underestimate the infiltration rate significantly during rainstorm periods. The SAI model is adopted in the spatial averaging hydrological model developed by the authors, and the results prove that it can be applied in the macro-scale hydrological and land surface process modeling in a promising way.

  6. Astrobiological Significance of Microbial Extremophiles (United States)

    Pikuta, Elena V.; Hoover, Richard B.


    The microflora of the cryosphere of planet Earth provides the best analogs for life forms that might be found in the permafrost or polar ice caps of Mars, near the surface of the cometary nuclei, or in the liquid water beneath and the ice crusts of icy moons of Jupiter and Saturn. The importance of study alkaliphilic microorganisms for astrobiology was enhanced by the findings of abundant carbonates and carbonate globules rimmed with possibly biogenic magnetites in association with the putative microfossils in the ALH84001 meteorite. Although the ALH84001 "nanofossils" were to small and simple to be unambiguously recognized as biogenic, they stimulated Astrobiology research and studies of microbial extremophiles and biomarkers in ancient rocks and meteorites. Recent studies of CI and CM carbonaceous meteorites have resulted in the detection of the well-preserved mineralized remains of coccoidal and filamentous microorganisms in cyanobacterial mats. Energy Dispersive X-ray Analysis has shown anomalous biogenic element ratios clearly indicating they are not recent biological contaminants. This paper reviews microbial extremophiles in context of their significance to Astrobiology. The study of halophilic microorganisms was started from work with saline soils and lakes, and one of the record of good growth for Haloferax mediterranei was shown at 30 percent NaC1. Although alkali-tolerant nitrifying bacteria had previously been reported, the first described alkaliphilic microorganism was the bacterium Streptococcus faecalis. Halophilic and alkaliphilic forms are relevant to conditions that might be found in closed impact basins and craters on Mars filled with evaporite deposits. The first obligately acidophilic bacterium described was Acidithiobacillus ferrooxydans (formally Thiobacillus ferrooxidans). Later thermophilic lithotrophic acidophiles were found, and the hyperacidophilic moderately thermophilic species of the genus Picrophilus were found to grow at negative p

  7. Astronomical Significance of Ancient Monuments (United States)

    Simonia, I.


    Astronomical significance of Gokhnari megalithic monument (eastern Georgia) is considered. Possible connection of Amirani ancient legend with Gokhnari monument is discussed. Concepts of starry practicality and solar stations are proposed.

  8. Historical Significant Volcanic Eruption Locations (United States)

    Department of Homeland Security — A significant eruption is classified as one that meets at least one of the following criteriacaused fatalities, caused moderate damage (approximately $1 million or...

  9. Model establishment of cervical cancer lymphatic metastasis and clinical significance of Prox-1%宫颈癌淋巴道转移模型的建立及Prox-1临床意义初探

    Institute of Scientific and Technical Information of China (English)

    李兰双; 胡丽娜


    目的 建立小鼠宫颈癌淋巴道转移模型,初步探讨Prox-1的临床意义.方法 将宫颈癌U27瘤株的单细胞悬液注入小鼠左爪垫,观察成瘤率、肿瘤生长及淋巴结转移情况.应用HE染色及CK免疫组化检测各级淋巴结中有无肿瘤转移;应用荧光定量PCR和Western blot检测肿瘤组织中VEGFR-3和Pmx-1在mRNA及蛋白水平的表达情况.结果 爪垫种植后成瘤率100%;淋巴结转移程度与接种时间显著相关;荧光定量PCR和Western blot结果显示,肿瘤组织中Prox-1 mRNA和蛋白在远处淋巴结转移组[(0.000 173±0.000 085),(0.108 7±0.049 9)]明显高于前哨淋巴结转移组[(0.000 058±0.000 022),(0.012 0±0.005 7)]及无淋巴结转移组[(0.000027±0.000 010),(0.003 8±0.001 4)],3组两两比较差异有统计学意义(P0.05).结论 小鼠爪垫皮下注射可成功建立宫颈癌淋巴道转移模型;Prox-1是预测肿瘤淋巴结转移及抗肿瘤淋巴转移的敏感指标.%Objective To establish the uterine cervical cancer model of lymphatic metastasis using Kun-ruing (Kin) mice and to explore the clinical significance of Prox-1. Methods The lymphatic metastasis model was estabhshed by injection of cervical cancer cells into the left natl pads of female Km mice. The tumor forma-tion rate, tumor growth and lymph node metastasis status were observed. At 5, 10, 15, and 20 d after inocula-tion, mice in one group were sacrificed for the specimens, including lymph nodes and tumors. Then HE dyeing and immunohistochemistry staining of cytokeratin were used for the detection of the occurrence of lymphatic me-tastasis or not, and fluorescent quantitation polymerase chain reaction (FQ-PCR) and Western-blot were used for the detection of the expressions of VEGFR-3 and Prox-1. Results The tumor formation rate was 100%. The lymph node metastasis was closely correlated with the inoculation time. FQ-PCR and Western blot demon-strated that Prox-1 mRNA and protein expressions in distant lymphatic

  10. Significance analysis of prognostic signatures.

    Directory of Open Access Journals (Sweden)

    Andrew H Beck

    Full Text Available A major goal in translational cancer research is to identify biological signatures driving cancer progression and metastasis. A common technique applied in genomics research is to cluster patients using gene expression data from a candidate prognostic gene set, and if the resulting clusters show statistically significant outcome stratification, to associate the gene set with prognosis, suggesting its biological and clinical importance. Recent work has questioned the validity of this approach by showing in several breast cancer data sets that "random" gene sets tend to cluster patients into prognostically variable subgroups. This work suggests that new rigorous statistical methods are needed to identify biologically informative prognostic gene sets. To address this problem, we developed Significance Analysis of Prognostic Signatures (SAPS which integrates standard prognostic tests with a new prognostic significance test based on stratifying patients into prognostic subtypes with random gene sets. SAPS ensures that a significant gene set is not only able to stratify patients into prognostically variable groups, but is also enriched for genes showing strong univariate associations with patient prognosis, and performs significantly better than random gene sets. We use SAPS to perform a large meta-analysis (the largest completed to date of prognostic pathways in breast and ovarian cancer and their molecular subtypes. Our analyses show that only a small subset of the gene sets found statistically significant using standard measures achieve significance by SAPS. We identify new prognostic signatures in breast and ovarian cancer and their corresponding molecular subtypes, and we show that prognostic signatures in ER negative breast cancer are more similar to prognostic signatures in ovarian cancer than to prognostic signatures in ER positive breast cancer. SAPS is a powerful new method for deriving robust prognostic biological signatures from clinically

  11. Validation of lower tropospheric carbon monoxide inferred from MOZART model simulation over India (United States)

    Yarragunta, Y.; Srivastava, S.; Mitra, D.


    In the present study, MOZART-4 (Model for Ozone and Related chemical Tracers-Version-4) simulation has been made from 2003 to 2007 and compared with satellite and in-situ observations with a specific focus on Indian subcontinent to illustrate the capabilities of MOZART-4 model. The model simulated CO have been compared with latest version (version-6) of MOPITT (Measurement Of Pollution In The Troposphere) carbon monoxide (CO) retrievals at 900, 800 and 700 hPa. Model reproduces major features present in satellite observations. However model significantly overestimates CO over the entire Indian region at 900 hPa and moderately overestimates at 800 hPa and 700 hPa. The frequency distribution of all simulated data points with respect to MOZART error shows maximum in the error range of 10-20% at all pressure levels. Over total Indian landmass, the percentage of gridded CO data that are being overestimated in the range of 0-30% at 900 hPa, 800 hPa and 700 hPa are 58%, 62% and 66% respectively. The study reflects very good correlation between two datasets over Central India (CI) and Southern India (SI). The coefficient of determination (r2) is found to be 0.68-0.78 and 0.70-0.78 over the CI and SI respectively. The weak correlation is evident over Northern India (NI) with r2 values of 0.1-0.3. Over Eastern India (EI), Good correlation at 800 hPa (r2 = 0.72) and 700 hPa (r2 = 0.66) whereas moderately weak correlation at 900 hPa (r2 = 0.48) has been observed. In contrast, Over Western India (WI), strong correlation is evident at 900 hPa (r2 = 0.64) and moderately weak association is found to be present at 800 hPa and 700 hPa. Model fairly reproduces seasonal cycle of CO in the lower troposphere over most of the Indian regions. However, during June to December, model shows overestimation over NI. The magnitude of overestimation is increasing linearly from 900 hPa to 700 hPa level. During April-June months, model results are coinciding with observed CO concentrations over SI

  12. Carbon and energy fluxes in cropland ecosystems: a model-data comparison

    Energy Technology Data Exchange (ETDEWEB)

    Lokupitiya, E.; Denning, A. S.; Schaefer, K.; Ricciuto, D.; Anderson, R.; Arain, M. A.; Baker, I.; Barr, A. G.; Chen, G.; Chen, J. M.; Ciais, P.; Cook, D. R.; Dietze, M.; El Maayar, M.; Fischer, M.; Grant, R.; Hollinger, D.; Izaurralde, C.; Jain, A.; Kucharik, C.; Li, Z.; Liu, S.; Li, L.; Matamala, R.; Peylin, P.; Price, D.; Running, S. W.; Sahoo, A.; Sprintsin, M.; Suyker, A. E.; Tian, H.; Tonitto, C.; Torn, M.; Verbeeck, Hans; Verma, S. B.; Xue, Y.


    Croplands are highly productive ecosystems that contribute to land–atmosphere exchange of carbon, energy, and water during their short growing seasons. We evaluated and compared net ecosystem exchange (NEE), latent heat flux (LE), and sensible heat flux (H) simulated by a suite of ecosystem models at five agricultural eddy covariance flux tower sites in the central United States as part of the North American Carbon Program Site Synthesis project. Most of the models overestimated H and underestimated LE during the growing season, leading to overall higher Bowen ratios compared to the observations. Most models systematically under predicted NEE, especially at rain-fed sites. Certain crop-specific models that were developed considering the high productivity and associated physiological changes in specific crops better predicted the NEE and LE at both rain-fed and irrigated sites. Models with specific parameterization for different crops better simulated the inter-annual variability of NEE for maize-soybean rotation compared to those models with a single generic crop type. Stratification according to basic model formulation and phenological methodology did not explain significant variation in model performance across these sites and crops. The under prediction of NEE and LE and over prediction of H by most of the models suggests that models developed and parameterized for natural ecosystems cannot accurately predict the more robust physiology of highly bred and intensively managed crop ecosystems. When coupled in Earth System Models, it is likely that the excessive physiological stress simulated in many land surface component models leads to overestimation of temperature and atmospheric boundary layer depth, and underestimation of humidity and CO2 seasonal uptake over agricultural regions.

  13. Application of the Stefan-Maxwell Equations to determine limitations of Fick's law when modeling organic vapor transport in sand columns (United States)

    Baehr, Arthur L.; Bruell, Clifford J.


    The organic component of the vapor phase of a porous medium contaminated by an immiscible organic liquid can be significant enough to violate the condition of a dilute species diffusing in a bulk phase assumed by Fick's law. The Stefan-Maxwell equations provide a more comprehensive model for quantifying steady state transport for a vapor phase composed of arbitrary proportions of its constituents. The application of both types of models to the analysis of column experiments demonstrates that use of a Fickian-based transport model can lead to significant overestimates of soil tortuosity constants. Further, the physical displacement of naturally occurring gases (e.g., O2), predicted by the Stefan-Maxwell model but not by application of Fick's Law, can be attributed improperly to a sink term such as microbial degradation in a Fickian-based transport model.

  14. Intercomparison of temperature trends in IPCC CMIP5 simulations with observations, reanalyses and CMIP3 models

    Directory of Open Access Journals (Sweden)

    J. Xu


    Full Text Available On the basis of the fifth Coupled Model Intercomparison Project (CMIP5 and the climate model simulations covering 1979 through 2005, the temperature trends and their uncertainties have been examined to note the similarities or differences compared to the radiosonde observations, reanalyses and the third Coupled Model Intercomparison Project (CMIP3 simulations. The results show noticeable discrepancies for the estimated temperature trends in the four data groups (radiosonde, reanalysis, CMIP3 and CMIP5, although similarities can be observed. Compared to the CMIP3 model simulations, the simulations in some of the CMIP5 models were improved. The CMIP5 models displayed a negative temperature trend in the stratosphere closer to the strong negative trend seen in the observations. However, the positive tropospheric trend in the tropics is overestimated by the CMIP5 models relative to CMIP3 models. While some of the models produce temperature trend patterns more highly correlated with the observed patterns in CMIP5, the other models (such as CCSM4 and IPSL_CM5A-LR exhibit the reverse tendency. The CMIP5 temperature trend uncertainty was significantly reduced in most areas, especially in the Arctic and Antarctic stratosphere, compared to the CMIP3 simulations. Similar to the CMIP3, the CMIP5 simulations overestimated the tropospheric warming in the tropics and Southern Hemisphere and underestimated the stratospheric cooling. The crossover point where tropospheric warming changes into stratospheric cooling occurred near 100 hPa in the tropics, which is higher than in the radiosonde and reanalysis data. The result is likely related to the overestimation of convective activity over the tropical areas in both the CMIP3 and CMIP5 models. Generally, for the temperature trend estimates associated with the numerical models including the reanalyses and global climate models, the uncertainty in the stratosphere is much larger than that in the troposphere, and the

  15. The expression and significance of extracellular ATP in murine acute liver injury model%胞外ATP在小鼠急性肝损伤中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    胡梅琮; 邹玲莉; 黄保军; 王磊


    Objective To observe the expression and significance of extracellular adenosine triphosphate (eATP) in concanavalin A (ConA)-induced murine acute liver injury model.Methods A total of 72 mice were randomly classified into control group (saline,36 cases)and ConA group (20 mg/kg ConA,36 cases).The blood specimens and liver tissues were collected at 2,6,12,18,24 and 48 h after injection.The activities of serum alanine aminotransferase (ALT)were measured by Reitman Frankel assay.Hematoxylin-eosin (HE)dyeing was carried out to assess the pathological change of liver tissue.The levels of eATP in serum were detected by chemiluminescence. Western-blot was employed to detect the expression of purinoceptor P2(P2X7).The contents of serum interleukin 1 beta (IL-1β)were assayed by enzyme-linked immunosorbent assay (ELISA).Results The ConA-induced murine acute liver injury model was constructed successfully.The level of eATP increased at 2 h after ConA injection,and reached peak at 18 h (700 nmol /L).Meanwhile,there expressed P2X7 in liver tissues.Compared with control group,the IL-1βlevels in serum of ConA group increased significantly (P<0.01).Conclusions In ConA-induced murine acute liver injury model,eATP releases from the injury liver tissues,and might influence the synthesis and secretion of inflammatory cytokine IL-1βthrough the P2X7 pathway,eventually aggravating the process of acute liver injury.%目的:探讨胞外三磷酸腺苷(eATP)在刀豆蛋白A(ConA)诱导小鼠急性肝损伤中的表达及意义。方法将72只昆明种小鼠随机分为对照组(36只)、ConA组(36只)。ConA组由尾静脉处注射20 mg/kg ConA,对照组注射同体积的无致热原生理盐水。2组分别于注射后2、6、12、18、24、48 h留取血液标本和肝脏标本。采用赖氏法检测血清丙氨酸氨基转移酶(ALT)活性,苏木素-伊红(HE )染色法检查肝组织病理学改变,化学发光技术检测血清eATP水平,免疫印

  16. Significant advancement in algebraic geometry

    Institute of Scientific and Technical Information of China (English)


    @@ Supported by a grant for Distinguished Young Scholars of the National Natural Science Foundation of China,Prof.SUN Xiaotao with the CAS Academy of Mathematics and Systems Science has recently achieved a research breakthrough in revealing the deep relationship between stability of vector bundles and Frobenius morphism.It is considered as significant work with important theoretical value.

  17. Vapor-liquid phase equilibria of water modelled by a Kim-Gordon potential

    Energy Technology Data Exchange (ETDEWEB)

    Maerzke, K A; McGrath, M J; Kuo, I W; Tabacchi, G; Siepmann, J I; Mundy, C J


    Gibbs ensemble Monte Carlo simulations were carried out to investigate the properties of a frozen-electron-density (or Kim-Gordon, KG) model of water along the vapor-liquid coexistence curve. Because of its theoretical basis, such a KG model provides for seamless coupling to Kohn-Sham density functional theory for use in mixed quantum mechanics/molecular mechanics (QM/MM) implementations. The Gibbs ensemble simulations indicate rather limited transferability of such a simple KG model to other state points. Specifically, a KG model that was parameterized by Barker and Sprik to the properties of liquid water at 300 K, yields saturated vapor pressures and a critical temperature that are significantly under- and over-estimated, respectively.

  18. Significance and Progress of Bionics

    Institute of Scientific and Technical Information of China (English)

    Yongxiang Lu


    The four topics are described including the driving force and source of the scientific and technological creation, the definition and history of the bionics, the important significance of bionics in the development of the human beings, and the leading edge and progress of bionics. The appetency of human for the creation is the essential motivity of the innovation in science and technology. Nature and society are the objects for us to cognize and serve, meanwhile, the best teachers for us to learn from them. It is only 5 million years for human's development, but evolution of life has over 3.5 billion years history. Although, copying the creation from the human being is important, however, it has much more potential and opportunity in imitating the nature, and more possibility to promote the ability of original innovation. The significance and progress of bionics are summarized, in this paper, and the leading edges of bionics, in the near future, are forecasted.

  19. Which Reconstruction Results are Significant? (United States)


    other significant result is due to Tutte [17]. Tutte’s Theorem: The characteristic polynomial of a graph can be reconstructed. Equivalently, two...hypomorphic graphs must have the same characteristic polynomial . Several points should be noted concerning this theorem: 1. The derivative of the...characteristic polynomial is the sum of the char- acteristic polynomials of the vertex-deleted subgraphs. Thus the characteristic polynomials of hypomorphic

  20. Robust Simulations and Significant Separations

    CERN Document Server

    Fortnow, Lance


    We define and study a new notion of "robust simulations" between complexity classes which is intermediate between the traditional notions of infinitely-often and almost-everywhere, as well as a corresponding notion of "significant separations". A language L has a robust simulation in a complexity class C if there is a language in C which agrees with L on arbitrarily large polynomial stretches of input lengths. There is a significant separation of L from C if there is no robust simulation of L in C. The new notion of simulation is a cleaner and more natural notion of simulation than the infinitely-often notion. We show that various implications in complexity theory such as the collapse of PH if NP = P and the Karp-Lipton theorem have analogues for robust simulations. We then use these results to prove that most known separations in complexity theory, such as hierarchy theorems, fixed polynomial circuit lower bounds, time-space tradeoffs, and the theorems of Allender and Williams, can be strengthened to signifi...

  1. Significance of biofilms in dentistry. (United States)

    Wróblewska, Marta; Strużycka, Izabela; Mierzwińska-Nastalska, Elżbieta


    In the past decades significant scientific progress has taken place in the knowledge about biofilms. They constitute multilayer conglomerates of bacteria and fungi, surrounded by carbohydrates which they produce, as well as substances derived from saliva and gingival fluid. Modern techniques showed significant diversity of the biofilm environment and a system of microbial communication (quorum sensing), enhancing their survival. At present it is believed that the majority of infections, particularly chronic with exacerbations, are a result of biofilm formation, particularly in the presence of biomaterials. It should be emphasised that penetration of antibiotics and other antimicrobial agents into deeper layers of a biofilm is poor, causing therapeutic problems and necessitating sometimes removal of the implant or prosthesis. Biofilms play an increasing role in dentistry as a result of more and more broad use in dental practice of plastic and implantable materials. Biofilms are produced on the surfaces of teeth as dental plaque, in the para-nasal sinuses, on prostheses, dental implants, as well as in waterlines of a dental unit, constituting a particular risk for severely immunocompromised patients. New methods of therapy and prevention of infections linked to biofilms are under development.

  2. Modeling overland flow-driven erosion across a watershed DEM using the Landlab modeling framework. (United States)

    Adams, J. M.; Gasparini, N. M.; Tucker, G. E.; Hobley, D. E. J.; Hutton, E. W. H.; Nudurupati, S. S.; Istanbulluoglu, E.


    Many traditional landscape evolution models assume steady-state hydrology when computing discharge, and generally route flow in a single direction, along the path of steepest descent. Previous work has demonstrated that, for larger watersheds or short-duration storms, hydrologic steady-state may not be achieved. In semiarid regions, often dominated by convective summertime storms, landscapes are likely heavily influenced by these short-duration but high-intensity periods of rainfall. To capture these geomorphically significant bursts of rain, a new overland flow method has been implemented in the Landlab modeling framework. This overland flow method routes a hydrograph across a landscape, and allows flow to travel in multiple directions out of a given grid node. This study compares traditional steady-state flow routing and incision methods to the new, hydrograph-driven overland flow and erosion model in Landlab. We propose that for short-duration, high-intensity precipitation events, steady-state, single-direction flow routing models will significantly overestimate discharge and erosion when compared with non-steady, multiple flow direction model solutions. To test this hypothesis, discharge and erosion are modeled using both steady-state and hydrograph methods. A stochastic storm generator is used to generate short-duration, high-intensity precipitation intervals, which drive modeled discharge and erosion across a watershed imported from a digital elevation model, highlighting Landlab's robust raster-gridding library and watershed modeling capabilities. For each storm event in this analysis, peak discharge at the outlet, incision rate at the outlet, as well as total discharge and erosion depth are compared between methods. Additionally, these results are organized by storm duration and intensity to understand how erosion rates scale with precipitation between both flow routing methods. Results show that in many cases traditional steady-state methods overestimate

  3. Glyoxal as a tracer of VOC oxidation chemistry: Comparison of measurements with model results for Blodgett Forest, California (United States)

    Huisman, Andrew; Carlton, Annmarie; Keutsch, Frank


    We present a study investigating Volatile Organic Compound (VOC) oxidation chemistry in the context of regional ozone (O3) production during the BEARPEX 2007 and 2009 campaigns at Blodgett Forest Research Station (BFRS) in the Sierra Nevada mountains, CA. Measurements are compared with results from a regional model (US EPA CMAQ) and a zero dimensional (0-D) box model based on the Master Chemical Mechanism (MCM). We use glyoxal (CHOCHO) and formaldehyde (HCHO) as tracers for generalized oxidation processes and employ ratios of compounds (e.g. CHOCHO / HCHO, CHOCHO / MPAN) to study plume evolution as doing so attenuates the influence of meteorology. One of the goals of this study is to investigate the utility of glyoxal as a tracer of VOC oxidation chemistry for measurement/model comparisons, for which formaldehyde has served in the past. In this context, we investigate the discrepancies between models and measurements, and the degree to which these can be attributed to the representation of glyoxal chemistry (e.g. yields) or whether these discrepancies reflect VOC-HOx-NOx oxidation more generally, which has implications for ozone and secondary organic aerosol formation. Model results from CMAQ and the 0-D box model substantially overestimate the absolute measured concentration of CHOCHO at BFRS, and the CMAQ model also shows poor agreement with the diurnal profile. The 0-D box model also overestimates CHOCHO in data taken at the Caltech Indoor Air Chambers, suggesting that 2nd- and/or higher-generation yields of CHOCHO from isoprene are substantially overestimated in the MCM. 0-D model results that use attenuated 2nd- and higher-generation production of CHOCHO from isoprene show enhanced agreement with chamber results. We will present model results of the 0-D Box Model from BFRS employing these reduced yields that show improved agreement with measurements and also compare these results with the other models. We also present results obtained with two modifications of

  4. The significance of constitutional values

    Directory of Open Access Journals (Sweden)

    HN Nisihara


    Full Text Available This article addresses the question of the meaning and legal significance of constitutional values in contemporary times. The article attends also to related questions namely, what constitute “constitutional values” and what are the limitations of the meaning afforded to this notion. Attention is paid in the particular, to freedom, equality and democracy as value-neutral criteria of fairness and government neutrality with reference to the South African and German contexts as well as to value-neutrality as a culturally conditioned value. The author concludes with a cosmopolitan view of freedom and the right to peace with reference to the constitutional texts of Japan and the United States.

  5. The significance of small streams (United States)

    Wohl, Ellen


    Headwaters, defined here as first- and secondorder streams, make up 70%‒80% of the total channel length of river networks. These small streams exert a critical influence on downstream portions of the river network by: retaining or transmitting sediment and nutrients; providing habitat and refuge for diverse aquatic and riparian organisms; creating migration corridors; and governing connectivity at the watershed-scale. The upstream-most extent of the channel network and the longitudinal continuity and lateral extent of headwaters can be difficult to delineate, however, and people are less likely to recognize the importance of headwaters relative to other portions of a river network. Consequently, headwaters commonly lack the legal protections accorded to other portions of a river network and are more likely to be significantly altered or completely obliterated by land use.

  6. [Hypertriglyceridemia: concept and clinical significance]. (United States)

    Hirano, Tsutomu


    Hypertriglyceridemia is a common lipid disorder as well as hypercholesterolemia. However clinical significance of hypertriglyceridemia is not fully understood because of its heterogeneous lipoprotein phenotypes and complex etiology. Severe hypertriglyceridemia increases the risk for pancreatitis, whereas mild or moderate hypertriglyceridemia may be a risk factor for cardiovascular disease. Patients with hypertriglyceridemia are usually accompanied by other cardiovascular related disorders, such as central obesity, type 2 diabetes, and liver steatosis. Ectopic fat accumulation is often seen in hypertriglyceridemic subjects and various organ injuries are developed by the lipotoxicity. Hypertriglyceridemia is strongly associated with remnant lipoprotein accumulation, increased small dense LDL, and low HDL-cholesterol. All these lipid abnormalities are recognized as cardiovascular risk factors. The pathophysiology of lipoprotein metabolism related to the hypertriglyceridemia is summarized in this brief review.

  7. Radiation modeling of a photo-reactor using a backward ray-tracing method: an insight into indoor photocatalytic oxidation. (United States)

    Pelzers, R S; Yu, Q L; Mangkuto, R A


    This article aims to understand the radiation behavior within a photo-reactor, following the ISO 22197-1:2007 standard. The RADIANCE lighting simulation tool, based on the backward ray-tracing modeling method, is employed for a numerical computation of the radiation field. The reflection of the glass cover in the photo-reactor and the test sample influence the amount of irradiance received by the test-sample surface in the photo-reactor setup. The reflection of a white sample limits the irradiance reduction by the glass cover to 1.4 %, but darker samples can lead to an overestimation up to 9.8 % when used in the same setup. This overestimation could introduce considerable error into the interpretation of experiments. Furthermore, this method demonstrates that the kinetics for indoor photocatalytic pollutant degradation can be refined through radiation modeling of the reactor setup. In addition, RADIANCE may aid in future modeling of the more complex indoor environment where radiation affects significantly photocatalytic activity.

  8. Determining Semantically Related Significant Genes. (United States)

    Taha, Kamal


    GO relation embodies some aspects of existence dependency. If GO term xis existence-dependent on GO term y, the presence of y implies the presence of x. Therefore, the genes annotated with the function of the GO term y are usually functionally and semantically related to the genes annotated with the function of the GO term x. A large number of gene set enrichment analysis methods have been developed in recent years for analyzing gene sets enrichment. However, most of these methods overlook the structural dependencies between GO terms in GO graph by not considering the concept of existence dependency. We propose in this paper a biological search engine called RSGSearch that identifies enriched sets of genes annotated with different functions using the concept of existence dependency. We observe that GO term xcannot be existence-dependent on GO term y, if x- and y- have the same specificity (biological characteristics). After encoding into a numeric format the contributions of GO terms annotating target genes to the semantics of their lowest common ancestors (LCAs), RSGSearch uses microarray experiment to identify the most significant LCA that annotates the result genes. We evaluated RSGSearch experimentally and compared it with five gene set enrichment systems. Results showed marked improvement.

  9. The cost of simplifying air travel when modeling disease spread.

    Directory of Open Access Journals (Sweden)

    Justin Lessler

    Full Text Available BACKGROUND: Air travel plays a key role in the spread of many pathogens. Modeling the long distance spread of infectious disease in these cases requires an air travel model. Highly detailed air transportation models can be over determined and computationally problematic. We compared the predictions of a simplified air transport model with those of a model of all routes and assessed the impact of differences on models of infectious disease. METHODOLOGY/PRINCIPAL FINDINGS: Using U.S. ticket data from 2007, we compared a simplified "pipe" model, in which individuals flow in and out of the air transport system based on the number of arrivals and departures from a given airport, to a fully saturated model where all routes are modeled individually. We also compared the pipe model to a "gravity" model where the probability of travel is scaled by physical distance; the gravity model did not differ significantly from the pipe model. The pipe model roughly approximated actual air travel, but tended to overestimate the number of trips between small airports and underestimate travel between major east and west coast airports. For most routes, the maximum number of false (or missed introductions of disease is small (<1 per day but for a few routes this rate is greatly underestimated by the pipe model. CONCLUSIONS/SIGNIFICANCE: If our interest is in large scale regional and national effects of disease, the simplified pipe model may be adequate. If we are interested in specific effects of interventions on particular air routes or the time for the disease to reach a particular location, a more complex point-to-point model will be more accurate. For many problems a hybrid model that independently models some frequently traveled routes may be the best choice. Regardless of the model used, the effect of simplifications and sensitivity to errors in parameter estimation should be analyzed.

  10. Reevaluation of lake trout and lake whitefish bioenergetics models (United States)

    Madenjian, Charles P.; Pothoven, Steve A.; Kao, Yu-Chun


    Using a corrected algorithm for balancing the energy budget, we reevaluated the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush) in the laboratory and for lake whitefish (Coregonus clupeaformis) in the laboratory and in the field. For lake trout, results showed that the bioenergetics model slightly overestimated food consumption by the lake trout when they were fed low and intermediate rations, whereas the model predicted food consumption by lake trout fed ad libitum without any detectable bias. The slight bias in model predictions for lake trout on restricted rations may have been an artifact of the feeding schedule for these fish, and we would therefore recommend application of the Wisconsin lake trout bioenergetics model to lake trout populations in the field without any revisions to the model. Use of the Wisconsin bioenergetics model for coregonids resulted in overestimation of food consumption by lake whitefish both in the laboratory and in the field by between 20 and 30%, on average. This overestimation of food consumption was most likely due to overestimation of respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit to the observed consumption in our laboratory tanks. The adjusted model predicted the consumption in the laboratory and the field without any detectable bias. Until a detailed lake whitefish respiration study can be conducted, we recommend application of our adjusted version of the Wisconsin generalized coregonid bioenergetics model to lake whitefish populations in the field.

  11. A Combined Thermodynamic and Kinetic Model for Barite Prediction at Oil Reservoir Conditions

    DEFF Research Database (Denmark)

    Zhen Wu, Bi Yun

    of this research was to develop a model, based on thermodynamics and kinetics, for predicting barite precipitation rates in saline waters at the pressures and temperatures of oil bearing reservoirs, using the geochemical modelling code PHREEQC. This task is complicated by the conditions where traditional methods....... Calculations for a well with seawater breakthrough results in an overestimation compared to scale samples, suggesting that significant amounts of barite precipitate in the reservoirs prior to entering to the wells. The combined model allows estimates of barite scaling rates that can be compared with field......In marine environments, barite (BaSO4) is a key proxy that has been used for understanding the biological and chemical evolution of oceans and for tracking the origin of fluids. In the oil industry, barite scale can clog pipelines and pores in the reservoirs, reducing oil yield. The goal...

  12. Modeling the potential area of occupancy at fine resolution may reduce uncertainty in species range estimates

    DEFF Research Database (Denmark)

    Jiménez-Alfaro, Borja; Draper, David; Nogues, David Bravo


    and maximum entropy modeling to assess whether different sampling (expert versus systematic surveys) may affect AOO estimates based on habitat suitability maps, and the differences between such measurements and traditional coarse-grid methods. Fine-scale models performed robustly and were not influenced...... by survey protocols, providing similar habitat suitability outputs with high spatial agreement. Model-based estimates of potential AOO were significantly smaller than AOO measures obtained from coarse-scale grids, even if the first were obtained from conservative thresholds based on the Minimal Predicted...... Area (MPA). As defined here, the potential AOO provides spatially-explicit measures of species ranges which are permanent in the time and scarcely affected by sampling bias. The overestimation of these measures may be reduced using higher thresholds of habitat suitability, but standard rules as the MPA...

  13. Social significance of community structure: Statistical view

    CERN Document Server

    Li, Hui-Jia


    Community structure analysis is a powerful tool for social networks, which can simplify their topological and functional analysis considerably. However, since community detection methods have random factors and real social networks obtained from complex systems always contain error edges, evaluating the significance of community structure partitioned is an urgent and important question. In this paper, integrating the specific characteristics of real society, we present a novel framework analyzing the significance of social community specially. The dynamics of social interactions are modeled by identifying social leaders and corresponding hierarchical structures. Instead of a direct comparison with the average outcome of a random model, we compute the similarity of a given node with the leader by the number of common neighbors. To determine the membership vector, an efficient community detection algorithm is proposed based on the position of nodes and their corresponding leaders. Then, using log-likelihood sco...

  14. Social significance of community structure: statistical view. (United States)

    Li, Hui-Jia; Daniels, Jasmine J


    Community structure analysis is a powerful tool for social networks that can simplify their topological and functional analysis considerably. However, since community detection methods have random factors and real social networks obtained from complex systems always contain error edges, evaluating the significance of a partitioned community structure is an urgent and important question. In this paper, integrating the specific characteristics of real society, we present a framework to analyze the significance of a social community. The dynamics of social interactions are modeled by identifying social leaders and corresponding hierarchical structures. Instead of a direct comparison with the average outcome of a random model, we compute the similarity of a given node with the leader by the number of common neighbors. To determine the membership vector, an efficient community detection algorithm is proposed based on the position of the nodes and their corresponding leaders. Then, using a log-likelihood score, the tightness of the community can be derived. Based on the distribution of community tightness, we establish a connection between p-value theory and network analysis, and then we obtain a significance measure of statistical form . Finally, the framework is applied to both benchmark networks and real social networks. Experimental results show that our work can be used in many fields, such as determining the optimal number of communities, analyzing the social significance of a given community, comparing the performance among various algorithms, etc.

  15. Social significance of community structure: Statistical view (United States)

    Li, Hui-Jia; Daniels, Jasmine J.


    Community structure analysis is a powerful tool for social networks that can simplify their topological and functional analysis considerably. However, since community detection methods have random factors and real social networks obtained from complex systems always contain error edges, evaluating the significance of a partitioned community structure is an urgent and important question. In this paper, integrating the specific characteristics of real society, we present a framework to analyze the significance of a social community. The dynamics of social interactions are modeled by identifying social leaders and corresponding hierarchical structures. Instead of a direct comparison with the average outcome of a random model, we compute the similarity of a given node with the leader by the number of common neighbors. To determine the membership vector, an efficient community detection algorithm is proposed based on the position of the nodes and their corresponding leaders. Then, using a log-likelihood score, the tightness of the community can be derived. Based on the distribution of community tightness, we establish a connection between p -value theory and network analysis, and then we obtain a significance measure of statistical form . Finally, the framework is applied to both benchmark networks and real social networks. Experimental results show that our work can be used in many fields, such as determining the optimal number of communities, analyzing the social significance of a given community, comparing the performance among various algorithms, etc.

  16. Gastric siderosis: patterns and significance. (United States)

    Marginean, Esmeralda C; Bennick, Michael; Cyczk, Jan; Robert, Marie E; Jain, Dhanpat


    Recently, we encountered 2 cases of diffuse iron deposition in gastric antral and fundic glandular epithelium, which in 1 patient eventually led to the diagnosis of hemochromatosis. Gastric mucosal siderosis (GS) has previously been described in hemochromatosis patients, alcoholics, and in association with iron medications. However, the prevalence of various patterns of iron deposition in the gastric mucosa and their clinical significance have not been studied in detail. The 2 index cases mentioned above and 500 additional consecutive gastric biopsies examined over a period of 8 months at our institution were stained for iron by the Prussian blue method. In addition, all patients with genetic hemochromatosis diagnosed by liver biopsy in our department between 1998 and 2003 who also had gastric biopsies were identified from the surgical pathology files and included in the study (n = 3). The location of iron deposition [stromal cells (endothelium, fibroblasts, macrophages), glandular epithelium, or extracellular] was recorded and subjectively graded as 1+ to 3+ according to the severity of deposition within the mucosa. Relevant histologic changes (inflammation, presence of H. pylori, ulceration) and clinical features were reviewed. Three patterns of GS were identified: A) "nonspecific GS" with predominant iron deposition in the stromal cells including macrophages, and focally in epithelium; B) "iron-pill gastritis" with often mild gastritis and reactive gastropathy type changes, and mostly extracellular deposition with focal stromal cells and epithelial deposition; and C) predominant deposition in antral and fundic glandular epithelium. Of the 500 cases studied, a total of 18 (3.6%) cases were found to have GS. Of these 18 cases, 11 (2.2%) showed pattern A, 4 (0.8%) showed pattern B, and 3 (0.6%) showed pattern C. The GS in patterns A and B was always focal or patchy (1+ to 2+), whereas in pattern C it was generally diffuse and strong (2+ to 3+). A history of oral

  17. Statistical significance of cis-regulatory modules

    Directory of Open Access Journals (Sweden)

    Smith Andrew D


    Full Text Available Abstract Background It is becoming increasingly important for researchers to be able to scan through large genomic regions for transcription factor binding sites or clusters of binding sites forming cis-regulatory modules. Correspondingly, there has been a push to develop algorithms for the rapid detection and assessment of cis-regulatory modules. While various algorithms for this purpose have been introduced, most are not well suited for rapid, genome scale scanning. Results We introduce methods designed for the detection and statistical evaluation of cis-regulatory modules, modeled as either clusters of individual binding sites or as combinations of sites with constrained organization. In order to determine the statistical significance of module sites, we first need a method to determine the statistical significance of single transcription factor binding site matches. We introduce a straightforward method of estimating the statistical significance of single site matches using a database of known promoters to produce data structures that can be used to estimate p-values for binding site matches. We next introduce a technique to calculate the statistical significance of the arrangement of binding sites within a module using a max-gap model. If the module scanned for has defined organizational parameters, the probability of the module is corrected to account for organizational constraints. The statistical significance of single site matches and the architecture of sites within the module can be combined to provide an overall estimation of statistical significance of cis-regulatory module sites. Conclusion The methods introduced in this paper allow for the detection and statistical evaluation of single transcription factor binding sites and cis-regulatory modules. The features described are implemented in the Search Tool for Occurrences of Regulatory Motifs (STORM and MODSTORM software.

  18. Systematic review and retrospective validation of prediction models for weight loss after bariatric surgery. (United States)

    Sharples, Alistair J; Mahawar, Kamal; Cheruvu, Chandra V N


    Patients often have less than realistic expectations of the weight loss they are likely to achieve after bariatric surgery. It would be useful to have a well-validated prediction tool that could give patients a realistic estimate of their expected weight loss. To perform a systematic review of the literature to identify existing prediction models and attempt to validate these models. University hospital, United Kingdom. A systematic review was performed. All English language studies were included if they used data to create a prediction model for postoperative weight loss after bariatric surgery. These models were then tested on patients undergoing bariatric surgery between January 1, 2013 and December 31, 2014 within our unit. An initial literature search produced 446 results, of which only 4 were included in the final review. Our study population included 317 patients. Mean preoperative body mass index was 46.1 ± 7.1. For 257 (81.1%) patients, 12-month follow-up was available, and mean body mass index and percentage excess weight loss at 12 months was 33.0 ± 6.7 and 66.1% ± 23.7%, respectively. All 4 of the prediction models significantly overestimated the amount of weight loss achieved by patients. The best performing prediction model in our series produced a correlation coefficient (R(2)) of .61 and an area under the curve of .71 on receiver operating curve analysis. All prediction models overestimated weight loss after bariatric surgery in our cohort. There is a need to develop better procedures and patient-specific models for better patient counselling. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  19. Validation of Goudriaan's model: a case study for maize.

    NARCIS (Netherlands)

    Singh, R.S.; Jacobs, A.F.G.


    The crop microclimate model of Goudriaan was tested, using data collected in a maize field in the Netherlands during one day in summer 1986. Except for the soil heat flux, latent and sensible heat fluxes were simulated reasonably well. Goudriaan's model overestimated the latent and sensible heat flu

  20. Total cloud cover from satellite observations and climate models

    Directory of Open Access Journals (Sweden)

    P. Probst


    Full Text Available Global and zonal monthly means of cloud cover fraction for total cloudiness (CF from the ISCCP D2 dataset are compared to same quantity produced by the 20th century simulations of 21 climate models from the World Climate Research Programme's (WCRP's Coupled Model Intercomparison Project phase 3 (CMIP3 multi-model dataset archived by the Program for Climate Model Diagnosis and Intercomparison (PCMDI. The comparison spans the time frame from January 1984 to December 1999 and the global and zonal average of CF are studied. The restriction to total cloudiness depends on the output of some models that does not include the 3D cloud structure. It is shown that the global mean of CF for the PCMDI/CMIP3 models, averaged over the whole period, exhibits a considerable variance and generally underestimates the ISCCP value. Very large discrepancies among models, and between models and observations, are found in the polar areas, where both models and satellite observations are less reliable, and especially near Antarctica. For this reason the zonal analysis is focused over the 60° S–60° N latitudinal belt, which includes the tropical area and mid latitudes. The two hemispheres are analyzed separately to show the variation of the amplitude of the seasonal cycle. Most models overestimate the yearly averaged values of CF over all of the analysed areas, while differences emerge in their ability to capture the amplitude of the seasonal cycle. The models represent, in a qualitatively correct way, the magnitude and the weak sign of the seasonal cycle over the whole geographical domain, but overestimate the strength of the signal in the tropical areas and at mid-latitudes, when taken separately. The interannual variability of the two yearly averages and of the amplitude of the seasonal cycle is greatly underestimated by all models in each area analysed. This work shows that the climate models have an heterogeneous behaviour in simulating the CF over

  1. 数字化原位子宫动脉血管3D可视化模型的构建及意义%Establishment and significance of 3D digitalization visualization model of uterine artery in situ

    Institute of Scientific and Technical Information of China (English)

    符爱贞; 石小田; 黄奕弟; 汪坤菊


    目的 探讨构建女性原位子宫动脉血管3D可视化模型和研究子宫动脉血管的结构特征.方法 采用聚乙烯醇-氧化铈血管造影术进行2例女尸盆腔动脉血管灌注,X线平位摄影、64排螺旋CT扫描后采集数据,导入计算机Mimics10.01重建软件进行子宫动脉血管3D可视化模型构建,观察子宫动脉血管的形态及血供分布情况.结果 ①构建的子宫动脉血管三维模型图像清晰,管道饱满,立体空间感强,均能清晰地显示子宫动脉的4级以上血管,各级分支血管的形态、走行、分布及各血管间的吻合显影清晰,效果满意.2例子宫及附件无实质性病变,为正常子宫.②清晰显示子宫动脉血管网的构建特点:子宫动脉自主干依次发出膀胱支、输尿管支、上行支、下行支等分支动脉;上行支较粗呈弓状沿子宫体侧缘迂曲上行,至宫角处分为宫底支、输卵管支和卵巢支,主要向子宫体和子宫附件供血;下行支较细分布于宫颈及阴道上段,但分布于阴道的血管较少;子宫动脉通过其卵巢支与卵巢动脉相交通;同时子宫动脉的供血还存有着明显的同侧倾向,双侧子宫动脉在子宫的中轴线处有少量细小的交通支.结论 采用聚乙烯醇-氧化铈血管造影术盆腔动脉血管灌注可构建理想的子宫动脉血管网3D可视化模型,为系统研究人子宫动脉血管网的形态结构和血供分布提供了血管解剖学基础.%Objective To discuss the establishment of 3D digitalization visualization model of vessels net in uterine artery in situ and research structure character of uterine artery. Methods The angiography with polyvinyl alcohol-ceria was used to make perfusion into pelvic cavity artery of two female bodys. The data was collected by prospositin scanning with X-ray scanner and CT scanning. 3D digitalization visualization model was established by Mimics10.0l based on imported data. The morphology of the

  2. Significance of primary irradiation creep in graphite

    Energy Technology Data Exchange (ETDEWEB)

    Erasmus, Christiaan, E-mail: [Pebble Bed Modular Reactor (Proprietary) Limited, PO Box 9396, Centurion 0046 (South Africa); Kok, Schalk [Advanced Mathematical Modelling, CSIR Modelling and Digital Science, Pretoria 0001 (South Africa); Hindley, Michael P. [Pebble Bed Modular Reactor (Proprietary) Limited, PO Box 9396, Centurion 0046 (South Africa)


    Traditionally primary irradiation creep is introduced into graphite analysis by applying the appropriate amount of creep strain to the model at the initial time-step. This is valid for graphite components that are subjected to high fast neutron flux fields and constant stress fields, but it does not allow for the effect of movement of stress locations around a graphite component during life, nor does it allow primary creep to be applied rate-dependently to graphite components subject to lower fast neutron flux. This paper shows that a differential form of primary irradiation creep in graphite combined with the secondary creep formulation proposed by Kennedy et al. performs well when predicting creep behaviour in experimental samples. The significance of primary irradiation creep in particular in regions with lower flux is investigated. It is shown that in low flux regions with a realistic operating lifetime primary irradiation creep is significant and is larger than secondary irradiation creep.

  3. Respiratory neuroplasticity - Overview, significance and future directions. (United States)

    Fuller, David D; Mitchell, Gordon S


    Neuroplasticity is an important property of the neural system controlling breathing. However, our appreciation for its importance is still relatively new, and we have much to learn concerning different forms of plasticity, their underlying mechanisms, and their biological and clinical significance. In this brief review, we discuss several well-studied models of respiratory plasticity, including plasticity initiated by inactivity in the respiratory system, intermittent and sustained hypoxia, and traumatic injury to the spinal cord. Other aspects of respiratory plasticity are considered in other contributions to this special edition of Experimental Neurology on respiratory plasticity. Finally, we conclude with discussions concerning the biological and clinical significance of respiratory motor plasticity, and areas in need of future research effort.

  4. Thermodynamic Significance of Human Basal Metabolism

    Institute of Scientific and Technical Information of China (English)



    The human basal state,a non-equilibrium steady state,is analysed in this paper in the light of the First and Second Laws of Thermodynamics whereby the thermodynamic significance of the basal metabolic rate and its distinction to the dissipation function and exergy loss are identified.The analysis demonstrates the correct expression of the effects of the blood flow on the heat balance in a human-body bio-heat model and the relationship between the basal metabolic rate and the blood perfusion.

  5. Comparison of ET estimations by the three-temperature model, SEBAL model and eddy covariance observations (United States)

    Zhou, Xinyao; Bi, Shaojie; Yang, Yonghui; Tian, Fei; Ren, Dandan


    The three-temperature (3T) model is a simple model which estimates plant transpiration from only temperature data. In-situ field experimental results have shown that 3T is a reliable evapotranspiration (ET) estimation model. Despite encouraging results from recent efforts extending the 3T model to remote sensing applications, literature shows limited comparisons of the 3T model with other remote sensing driven ET models. This research used ET obtained from eddy covariance to evaluate the 3T model and in turn compared the model-simulated ET with that of the more traditional SEBAL (Surface Energy Balance Algorithm for Land) model. A field experiment was conducted in the cotton fields of Taklamakan desert oasis in Xinjiang, Northwest China. Radiation and surface temperature were obtained from hyperspectral and thermal infrared images for clear days in 2013. The images covered the time period of 0900-1800 h at four different phenological stages of cotton. Meteorological data were automatically recorded in a station located at the center of the cotton field. Results showed that the 3T model accurately captured daily and seasonal variations in ET. As low dry soil surface temperatures induced significant errors in the 3T model, it was unsuitable for estimating ET in the early morning and late afternoon periods. The model-simulated ET was relatively more accurate for squaring, bolling and boll-opening stages than for seedling stage of cotton during when ET was generally low. Wind speed was apparently not a limiting factor of ET in the 3T model. This was attributed to the fact that surface temperature, a vital input of the model, indirectly accounted for the effect of wind speed on ET. Although the 3T model slightly overestimated ET compared with SEBAL and eddy covariance, it was generally reliable for estimating daytime ET during 0900-1600 h.

  6. SodA is a major metabolic antioxidant in Brucella abortus 2308 that plays a significant, but limited, role in the virulence of this strain in the mouse model. (United States)

    Martin, Daniel W; Baumgartner, John E; Gee, Jason M; Anderson, Eric S; Roop, R Martin


    The gene designated BAB1_0591 in the Brucella abortus 2308 genome sequence encodes the manganese-cofactored superoxide dismutase SodA. An isogenic sodA mutant derived from B. abortus 2308, designated JB12, displays a small colony phenotype, increased sensitivity in vitro to endogenous superoxide generators, hydrogen peroxide and exposure to acidic pH, and a lag in growth when cultured in rich and minimal media that can be rescued by the addition of all 20 amino acids to the growth medium. B. abortus JB12 exhibits significant attenuation in both cultured murine macrophages and experimentally infected mice, but this attenuation is limited to the early stages of infection. Addition of the NADPH oxidase inhibitor apocynin to infected macrophages does not alleviate the attenuation exhibited by JB12, suggesting that the basis for the attenuation of the B. abortus sodA mutant is not an increased sensitivity to exogenous superoxide generated through the oxidative burst of host phagocytes. It is possible, however, that the increased sensitivity of the B. abortus sodA mutant to acid makes it less resistant than the parental strain to killing by the low pH encountered during the early stages of the development of the brucella-containing vacuoles in macrophages. These experimental findings support the proposed role for SodA as a major cytoplasmic antioxidant in brucella. Although this enzyme provides a clear benefit to B. abortus 2308 during the early stages of infection in macrophages and mice, SodA appears to be dispensable once the brucellae have established an infection.

  7. Have We Overestimated Saline Aquifer CO2 Storage Capacities? Avons-nous surestimé les capacités de stockage de CO2 des aquifères salins ?

    Directory of Open Access Journals (Sweden)

    Thibeau S.


    this approach, it is applied to the Utsira aquifer in the North Sea. In Sections 3 and 4, we discuss possible effects that may lead to higher or lower CO2 storage efficiencies. Water production appears to be an attractive strategy in order to address regional scale pressure build up and, consequently, to increase the storage capacity. Following these quantitative applications, we recommend to evaluate the CO2 storage capacities of an aquifer, during a screening study for ranking purposes, using a pressure and compressibility formula rather than a volumetric approach, in order to avoid large overestimation of the aquifer storage capacity. Further studies are naturally required to validate the storage capacities at a qualification stage. Au cours d’opérations à grande échelle de stockage géologique de CO2 dans des aquifères salins, la pression des fluides dans les formations va augmenter, mais devra rester sous des limites définies par des contraintes d’intégrité des sites de stockage. La hausse de pression est la conséquence de deux effets distincts. Premièrement, la pression augmente localement autour des injecteurs de CO2 pour permettre l’injection du CO2 dans les nappes. Cet effet peut être contrôlé en ajoutant des injecteurs de CO2. Deuxièmement, la pression va augmenter à une échelle régionale, soit parce que l’aquifère est fermée, soit parce que le flux d’eau s’échappant de la zone pressurisée ne compense pas volumétriquement le CO2 injecté. Ce second effet ne peut pas être maîtrisé en augmentant le nombre d’injecteurs. Dans la première section du papier, nous discutons sur des évaluations mondiales ou régionales de capacités de stockage du CO2 en aquifère, tant du point de vue de la quantité que de l’efficacité de stockage. Ces capacités sont principalement basées sur une approche volumétrique : la capacité de stockage est la somme des volumes de CO2 pouvant être stockés par différents processus de pi

  8. Ranking and validation of the spallation models for description of intermediate mass fragment emission from p + Ag collisions at 480 MeV incident proton beam energy (United States)

    Sharma, Sushil K.; Kamys, Bogusław; Goldenbaum, Frank; Filges, Detlef


    Double-differential cross-sections d2σ/dΩ dE for isotopically identified intermediate mass fragments ( 6Li up to 27Mg from nuclear reactions induced by 480 MeV protons impinging on a silver target were analyzed in the frame of a two-step model. The first step of the reaction was described by the intranuclear cascade model INCL4.6 and the second one by four different models (ABLA07,GEM2, GEMINI++, and SMM). The experimental spectra reveal the presence of low-energy, isotropic as well as high-energy, forward-peaked contributions. The INCL4.6 model offers a possibility to describe the latter contribution for light intermediate mass fragments by coalescence of the emitted nucleons. The qualitative agreement of the model predictions with the data was observed but the high-energy tails of the spectra were significantly overestimated. The shape of the isotropic part of the spectra was reproduced by all four models. The GEM2 model strongly underestimated the value of the cross-sections for heavier IMF whereas the SMM and ABLA07 models generally overestimated the data. The best quantitative description of the data was offered by GEMINI++, however, a discrepancy between the data and the model cross-sections still remained for almost all reaction products, especially at forward angles. It indicates that non-equilibrium processes are present which cannot be reproduced by the applied models. The goodness of the data description was judged quantitatively using two statistical deviation factors, the H-factor and the M-factor, as a tool for ranking and validation of the theoretical models.

  9. Evaluation of daily maximum and minimum 2-m temperatures as simulated with the regional climate model COSMO-CLM over Africa

    Energy Technology Data Exchange (ETDEWEB)

    Kraehenmann, Stefan; Kothe, Steffen; Ahrens, Bodo [Frankfurt Univ. (Germany). Inst. for Atmospheric and Environmental Sciences; Panitz, Hans-Juergen [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany)


    The representation of the diurnal 2-m temperature cycle is challenging because of the many processes involved, particularly land-atmosphere interactions. This study examines the ability of the regional climate model COSMO-CLM (version 4.8) to capture the statistics of daily maximum and minimum 2-m temperatures (Tmin/Tmax) over Africa. The simulations are carried out at two different horizontal grid-spacings (0.22 and 0.44 ), and are driven by ECMWF ERA-Interim reanalyses as near-perfect lateral boundary conditions. As evaluation reference, a high-resolution gridded dataset of daily maximum and minimum temperatures (Tmin/Tmax) for Africa (covering the period 2008-2010) is created using the regression-kriging-regression-kriging (RKRK) algorithm. RKRK applies, among other predictors, the remotely sensed predictors land surface temperature and cloud cover to compensate for the missing information about the temperature pattern due to the low station density over Africa. This dataset allows the evaluation of temperature characteristics like the frequencies of Tmin/Tmax, the diurnal temperature range, and the 90{sup th} percentile of Tmax. Although the large-scale patterns of temperature are reproduced well, COSMO-CLM shows significant under- and overestimation of temperature at regional scales. The hemispheric summers are generally too warm and the day-to-day temperature variability is overestimated over northern and southern extra-tropical Africa. The average diurnal temperature range is underestimated by about 2 C across arid areas, yet overestimated by around 2 C over the African tropics. An evaluation based on frequency distributions shows good model performance for simulated Tmin (the simulated frequency distributions capture more than 80% of the observed ones), but less well performance for Tmax (capture below 70%). Further, over wide parts of Africa a too large fraction of daily Tmax values exceeds the observed 90{sup th} percentile of Tmax, particularly across

  10. Radical precursors and related species from traffic as observed and modeled at an urban highway junction. (United States)

    Rappenglück, Bernhard; Lubertino, Graciela; Alvarez, Sergio; Golovko, Julia; Czader, Beata; Ackermann, Luis


    Nitrous acid (HONO) and formaldehyde (HCHO) are important precursors for radicals and are believed to favor ozone formation significantly. Traffic emission data for both compounds are scarce and mostly outdated. A better knowledge of today's HCHO and HONO emissions related to traffic is needed to refine air quality models. Here the authors report results from continuous ambient air measurements taken at a highway junction in Houston, Texas, from July 15 to October 15, 2009. The observational data were compared with emission estimates from currently available mobile emission models (MOBILE6; MOVES [MOtor Vehicle Emission Simulator]). Observations indicated a molar carbon monoxide (CO) versus nitrogen oxides (NO(x)) ratio of 6.01 +/- 0.15 (r2 = 0.91), which is in agreement with other field studies. Both MOBILE6 and MOVES overestimate this emission ratio by 92% and 24%, respectively. For HCHO/CO, an overall slope of 3.14 +/- 0.14 g HCHO/kg CO was observed. Whereas MOBILE6 largely underestimates this ratio by 77%, MOVES calculates somewhat higher HCHO/CO ratios (1.87) than MOBILE6, but is still significantly lower than the observed ratio. MOVES shows high HCHO/CO ratios during the early morning hours due to heavy-duty diesel off-network emissions. The differences of the modeled CO/NO(x) and HCHO/CO ratios are largely due to higher NO(x) and HCHO emissions in MOVES (30% and 57%, respectively, increased from MOBILE6 for 2009), as CO emissions were about the same in both models. The observed HONO/NO(x) emission ratio is around 0.017 +/- 0.0009 kg HONO/kg NO(x) which is twice as high as in MOVES. The observed NO2/NO(x) emission ratio is around 0.16 +/- 0.01 kg NO2/kg NO(x), which is a bit more than 50% higher than in MOVES. MOVES overestimates the CO/CO2 emission ratio by a factor of 3 compared with the observations, which is 0.0033 +/- 0.0002 kg CO/kg CO2. This as well as CO/NO(x) overestimation is coming from light-duty gasoline vehicles.

  11. A Global Atmospheric Model of Meteoric Iron (United States)

    Feng, Wuhu; Marsh, Daniel R.; Chipperfield, Martyn P.; Janches, Diego; Hoffner, Josef; Yi, Fan; Plane, John M. C.


    The first global model of meteoric iron in the atmosphere (WACCM-Fe) has been developed by combining three components: the Whole Atmosphere Community Climate Model (WACCM), a description of the neutral and ion-molecule chemistry of iron in the mesosphere and lower thermosphere (MLT), and a treatment of the injection of meteoric constituents into the atmosphere. The iron chemistry treats seven neutral and four ionized iron containing species with 30 neutral and ion-molecule reactions. The meteoric input function (MIF), which describes the injection of Fe as a function of height, latitude, and day, is precalculated from an astronomical model coupled to a chemical meteoric ablation model (CABMOD). This newly developed WACCM-Fe model has been evaluated against a number of available ground-based lidar observations and performs well in simulating the mesospheric atomic Fe layer. The model reproduces the strong positive correlation of temperature and Fe density around the Fe layer peak and the large anticorrelation around 100 km. The diurnal tide has a significant effect in the middle of the layer, and the model also captures well the observed seasonal variations. However, the model overestimates the peak Fe+ concentration compared with the limited rocket-borne mass spectrometer data available, although good agreement on the ion layer underside can be obtained by adjusting the rate coefficients for dissociative recombination of Fe-molecular ions with electrons. Sensitivity experiments with the same chemistry in a 1-D model are used to highlight significant remaining uncertainties in reaction rate coefficients, and to explore the dependence of the total Fe abundance on the MIF and rate of vertical transport.

  12. Structural mode significance using INCA. [Interactive Controls Analysis computer program (United States)

    Bauer, Frank H.; Downing, John P.; Thorpe, Christopher J.


    Structural finite element models are often too large to be used in the design and analysis of control systems. Model reduction techniques must be applied to reduce the structural model to manageable size. In the past, engineers either performed the model order reduction by hand or used distinct computer programs to retrieve the data, to perform the significance analysis and to reduce the order of the model. To expedite this process, the latest version of INCA has been expanded to include an interactive graphical structural mode significance and model order reduction capability.

  13. Structural mode significance using INCA. [Interactive Controls Analysis computer program (United States)

    Bauer, Frank H.; Downing, John P.; Thorpe, Christopher J.


    Structural finite element models are often too large to be used in the design and analysis of control systems. Model reduction techniques must be applied to reduce the structural model to manageable size. In the past, engineers either performed the model order reduction by hand or used distinct computer programs to retrieve the data, to perform the significance analysis and to reduce the order of the model. To expedite this process, the latest version of INCA has been expanded to include an interactive graphical structural mode significance and model order reduction capability.

  14. Assessing statistical significance in causal graphs

    Directory of Open Access Journals (Sweden)

    Chindelevitch Leonid


    Full Text Available Abstract Background Causal graphs are an increasingly popular tool for the analysis of biological datasets. In particular, signed causal graphs--directed graphs whose edges additionally have a sign denoting upregulation or downregulation--can be used to model regulatory networks within a cell. Such models allow prediction of downstream effects of regulation of biological entities; conversely, they also enable inference of causative agents behind observed expression changes. However, due to their complex nature, signed causal graph models present special challenges with respect to assessing statistical significance. In this paper we frame and solve two fundamental computational problems that arise in practice when computing appropriate null distributions for hypothesis testing. Results First, we show how to compute a p-value for agreement between observed and model-predicted classifications of gene transcripts as upregulated, downregulated, or neither. Specifically, how likely are the classifications to agree to the same extent under the null distribution of the observed classification being randomized? This problem, which we call "Ternary Dot Product Distribution" owing to its mathematical form, can be viewed as a generalization of Fisher's exact test to ternary variables. We present two computationally efficient algorithms for computing the Ternary Dot Product Distribution and investigate its combinatorial structure analytically and numerically to establish computational complexity bounds. Second, we develop an algorithm for efficiently performing random sampling of causal graphs. This enables p-value computation under a different, equally important null distribution obtained by randomizing the graph topology but keeping fixed its basic structure: connectedness and the positive and negative in- and out-degrees of each vertex. We provide an algorithm for sampling a graph from this distribution uniformly at random. We also highlight theoretical

  15. Improving Accuracy in Arrhenius Models of Cell Death: Adding a Temperature-Dependent Time Delay. (United States)

    Pearce, John A


    The Arrhenius formulation for single-step irreversible unimolecular reactions has been used for many decades to describe the thermal damage and cell death processes. Arrhenius predictions are acceptably accurate for structural proteins, for some cell death assays, and for cell death at higher temperatures in most cell lines, above about 55 °C. However, in many cases--and particularly at hyperthermic temperatures, between about 43 and 55 °C--the particular intrinsic cell death or damage process under study exhibits a significant "shoulder" region that constant-rate Arrhenius models are unable to represent with acceptable accuracy. The primary limitation is that Arrhenius calculations always overestimate the cell death fraction, which leads to severely overoptimistic predictions of heating effectiveness in tumor treatment. Several more sophisticated mathematical model approaches have been suggested and show much-improved performance. But simpler models that have adequate accuracy would provide useful and practical alternatives to intricate biochemical analyses. Typical transient intrinsic cell death processes at hyperthermic temperatures consist of a slowly developing shoulder region followed by an essentially constant-rate region. The shoulder regions have been demonstrated to arise chiefly from complex functional protein signaling cascades that generate delays in the onset of the constant-rate region, but may involve heat shock protein activity as well. This paper shows that acceptably accurate and much-improved predictions in the simpler Arrhenius models can be obtained by adding a temperature-dependent time delay. Kinetic coefficients and the appropriate time delay are obtained from the constant-rate regions of the measured survival curves. The resulting predictions are seen to provide acceptably accurate results while not overestimating cell death. The method can be relatively easily incorporated into numerical models. Additionally, evidence is presented

  16. Assessing a soft twin tunneling numerical model using field data

    Institute of Scientific and Technical Information of China (English)

    Ke-shuan Ma; Lie-yun Ding


    Using a five-floor building affected by the Yangtze River highway tunnels in Wuhan as the engineering background, we have constructed a free-field model and a coupled model to study the soil, lining, foundations and upper structure, and analyze the rules of movements of building foundation and ground induced by single tunnel and twin tunnel excavation with the Finite Element Analysis method. It is shown that for the coupled model, the longitudinal displacement of each foundation increases slowly when the tunnel face gets close to the foundation section and then increases fast when the tunnel face moves away from the foundation during the single and twin tunneling. For a single tunnel, the surface settlements are overestimated by the free-field and coupled tunnel. This might be crucial in urban areas. Regarding the maximum settlements and the width of the settlement trough, the difference between the free-field model and the coupled model is quite obvious. This comparison with the field measurement value reveals that the coupled model seems to be superior to the free-field model. These results are of instructive significance for design and excavation.

  17. Decadal water balance of a temperate Scots pine forest (Pinus sylvestris L. based on measurements and modelling

    Directory of Open Access Journals (Sweden)

    I. A. Janssens


    Full Text Available Multi-year, multi-technique studies often yield key insights into methodological limitations but also process-level interactions that would otherwise go un-noticed if analysed at one point in time or in isolation. We examined the components of forest water balance for an 80-year-old Scots pine (Pinus sylvestris L. stand in the Campine region of Belgium over a ten year period using five very different approaches; our methods ranged from data intensive measurements to process model simulations. Specifically, we used the conservative ion method (CI, the Eddy Covariance technique (EC, an empirical model (WATBAL, and two process models that vary greatly in their temporal and spatial scaling, the ORCHIDEE global land-surface model and SECRETS a stand- to ecosystem-scale biogeochemical process model. Herein we used the EC technique as a standard for the evapotranspiration (ET estimates. We also examined ET and drainage in ORCHIDEE as influenced by climate change scenarios from the Hadley model. Results demonstrated that the two process models corresponded well to the seasonal patterns and yearly totals of ET from the EC approach. However, both WATBAL and CI approaches overestimated ET when compared to the EC estimates. Overestimation of ET by WATBAL increased as ET increased. We found positive relationships between ET and the process drivers to ET (i.e., vapour pressure deficit [VPD], mean air temperature [Tair], and global radiation [Rg] for SECRETS, ORCHIDEE, and the EC estimates, though few were significant. Estimates of ET from WATBAL and the CI approach were uncoupled from VPD, Tair, and Rg. Independent of the method examined, ET exhibited low interannual variability. Consequently, drainage fluxes were highly correlated with annual precipitation for all five approaches examined. Estimates of ET increased in climate change scenarios for ORCHIDEE while drainage decreased.

  18. Comparison of midlatitude ionospheric F region peak parameters and topside Ne profiles from IRI2012 model prediction with ground-based ionosonde and Alouette II observations (United States)

    Gordiyenko, G. I.; Yakovets, A. F.


    difference in the shape of the Alouette-, NeQuick-, IRI02-coorr, and IRI2001-derived Ne profiles, with overestimated Ne values at some altitudes and underestimated Ne values at others. The results obtained in the study showed that the observation-model differences were significant especially for the real observed (not median) data. For practical application, it is clearly important for the IRI2012 model to be adapted to the observed F2-layer peak parameters. However, the model does not offer a simple solution to predict the shape of the vertical electron density profile in the topside ionosphere, because of the problem with the topside shape parameters.

  19. Modeling the hydrological significance of wetland restoration scenarios. (United States)

    Martinez-Martinez, Edwin; Nejadhashemi, A Pouyan; Woznicki, Sean A; Love, Bradley J


    Wetlands provide multiple socio-economic benefits, among them mitigating flood through short- and long-term water storage functions and assisting with reduction of downstream flood peaks. However, their effectiveness in controlling floods is dictated by wetland size and distribution within a watershed. Due to the complexity of wetland hydrological processes at the watershed scale, the Soil and Water Assessment Tool (SWAT) was used to study the impact of wetland restoration on streamflow rates and peaks in the Shiawassee River watershed of Michigan. Wetland restoration scenarios were developed based on combinations of wetland area (50, 100, 250, and 500 ha) and wetland depth (15, 30, 61, and 91 cm). Increasing wetland area, rather than depth, had a greater impact on long-term average daily streamflow. Wetland implementation resulted in negligible reductions in daily peak flow rates and frequency of peak flow events at the watershed outlet. In developing high impact areas for wetland restoration, similar locations were identified for reduction of subbasin and watershed outlet streamflow. However, the best combinations of area/depth differed depending on the goal of the restoration plan. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Modeling cell-in-cell structure into its biological significance


    He, M-f; Wang, S.; Wang, Y; Wang, X-N.


    Although cell-in-cell structure was noted 100 years ago, the molecular mechanisms of ‘entering' and the destination of cell-in-cell remain largely unclear. It takes place among the same type of cells (homotypic cell-in-cell) or different types of cells (heterotypic cell-in-cell). Cell-in-cell formation affects both effector cells and their host cells in multiple aspects, while cell-in-cell death is under more intensive investigation. Given that cell-in-cell has an important role in maintainin...

  1. A Simple and Effective Closed-Form GN-Model Correction Formula Accounting for Signal Non-Gaussian Distribution

    CERN Document Server

    Carena, A; Curri, V; Poggiolini, P; Jiang, Y; Forghieri, F


    The GN-model has been shown to overestimate the variance of non-linearity due to the signal Gaussianity approximation, leading to realistic system maximum reach predictions which may be pessimistic by about 5% to 15%, depending on fiber type and system set-up. Analytical corrections have been proposed, which however substantially increase the model complexity. In this paper we provide a closed-form simple GN-model correction which we show to be very effective in correcting for the GN-model tendency to overestimate non-linearity. Our formula also allows to clearly identify the correction dependence on key system parameters, such as the span length and loss.

  2. Modelling the Caspian Sea and its catchment area using a coupled regional atmosphere-ocean model (RegCM4-ROMS: model design and preliminary results

    Directory of Open Access Journals (Sweden)

    U. U. Turuncoglu


    Full Text Available We describe the development of a coupled regional atmosphere-ocean model (RegCM4-ROMS and its implementation over the Caspian Sea basin. The coupled model is run for the period 1999–2008 (after a spin up of 4 yr and it is compared to corresponding stand alone model simulations and a simulation in which a distributed 1d lake model is run for the Caspian Sea. All model versions show a good performance in reproducing the climatology of the Caspian Sea basin, with relatively minor differences across them. The coupled ROMS produces realistic, although somewhat overestimated, Caspian Sea Surface Temperature (SST, with a considerable improvement compared to the use of the simpler coupled lake model. Simulated near surface salinity and sea currents are also realistic, although the upwelling over the eastern coastal regions is underestimated. The sea ice extent over the shallow northern shelf of the Caspian Sea and its seasonal evolution are well reproduced, however, a significant negative bias in sea-ice fraction exists due to the relatively poor representation of the bathymetry. ROMS also calculates the Caspian Sea Level (CSL, showing that for the present experiment excessive evaporation over the lake area leads to a drift in estimated CSL. Despite this problem, which requires further analysis due to many uncertainties in the estimation of CSL, overall the coupled RegCM4-ROMS system shows encouraging results in reproducing both the climatology of the region and the basic characteristics of the Caspian Sea.

  3. Inspiration and Intellect: Significant Learning in Musical Forms and Analysis (United States)

    Kelley, Bruce C.


    In his book "Creating Significant Learning Experiences" (2003), Dee Fink challenges professors to create a deep vision for the courses they teach. Educators often have a vision for what their courses could be, but often lack a model for instituting change. Fink's book provides that model. In this article, the author describes how this model helped…

  4. Modelling the luminous efficacy of solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, E. [Universidad Autonoma de Madrid (Spain). Dpto. de Fisica Aplicada; Soler, A.; Robledo, L. [Universidad de Madrid (Spain). Dpto. de Fisic a e Instalaciones Aplicadas


    The global and diffuse luminous efficacy models proposed in Muneer (1995), Muneer and Kinghorn (1997), have been tested with experimental data obtained in Madrid. When the models with local coefficients are statistically assessed with local data, global illuminance L{sub g} is estimated with an acceptable accuracy, but diffuse illuminance L{sub d} is overestimated for L{sub d} higher than about 25 klux. (author)

  5. Model Simulations of Ozone in the Summer Lower Stratosphere (United States)

    Douglass, Anne R.; Kawa, S. R.


    The Goddard 3D chemistry and transport model (CTM) uses winds and temperatures from the Goddard Earth Observing System Data Assimilation System (GEOS DAS); thus CTM simulations can be compared directly with observations from satellite, balloon and aircraft. In general, aspects of these comparisons show remarkable agreement between observation and model. One significant difference is that the model ozone is high biased below the ozone peak. The bias is apparently largest at high latitudes during the summer months. At the same time, comparisons with HALOE observations show that at mid to high latitudes, the ozone mixing ratio peak appears persistently at a lower altitude than observed by HALOE; the peak mixing ratio is also overestimated by the model. Both transport and photochemistry are possible contributors to the biased ozone in the lower stratosphere - excessive downward motion would increase lower stratospheric ozone, as would a too large vertical gradient in ozone. On the other hand, comparisons of model N2O and NOy with observations suggest transport deficiencies in the opposite sense, i.e., model N2O can be high relative to observations (particularly during winter), suggesting the need for stronger downward transport. Sensitivity studies have been carried out using parameterizations for ozone production and loss, NOy production and loss, and N2O loss. The goal of these studies is to clarify how problems in the photochemical scheme at and above the ozone peak influence the lower stratospheric ozone.

  6. Field clearance of an intertidal bivalve bed: relative significance of the co-occurring blue mussel Mytilus edulis and Pacific oyster Crassostrea gigas

    DEFF Research Database (Denmark)

    Vismann, Bent; Holm, Mark Wejlemann; Davids, Jens;


    At an approximately 12 000 m2 sheltered intertidal bivalve bed in the western part of the Limfjord, Denmark, the Pacific oyster Crassostrea gigas co-occurs with the blue mussel Mytilus edulis. The relative significance of the impact of the 2 species on phytoplankton density during a tidal cycle....... However, the estimated water column cleared during low tide is overestimated due to phytoplankton depletion. Hence, it is concluded that the bivalve bed clears the water close to 1 time each tidal cycle. This, together with a low dry weight of soft parts, indicates that the bivalve bed, in general...

  7. Importance of pressure gradient in solid oxide fuel cell electrodes for modeling study (United States)

    Ni, Meng; Leung, Dennis Y. C.; Leung, Michael K. H.

    The pressure gradients in the electrodes of a solid oxide fuel cell (SOFC) are frequently neglected without any justification in calculating the concentration overpotentials of the SOFC electrodes in modeling studies. In this short communication, a comparative study has been conducted to study the effect of pressure gradients on mass transfer and the resulting concentration overpotentials of an SOFC running on methane (CH 4) fuel. It is found that the pressure gradients in both anode and cathode are significant in the fuel cell electrochemical activities. Neglecting the anode pressure gradient in the calculation can lead to underestimation of the concentration overpotential by about 20% at a typical current density of 5000 A m -2 and at a temperature of 1073 K. The deviation can be even larger at a higher temperature. At the cathode, neglecting the pressure gradient can result in overestimation of the concentration overpotential by about 10% under typical working conditions.

  8. Impact of axisymmetric mass models for dwarf spheroidal galaxies on indirect dark matter searches

    CERN Document Server

    Klop, Niki; Hayashi, Kohei; Ando, Shin'ichiro


    Dwarf spheroidals are low-luminosity satellite galaxies of the Milky Way highly dominated by dark matter. Therefore, they are prime targets to search for signals from dark matter annihilation using gamma-ray observations. We analyse about 7 years of PASS8 Fermi data for seven classical dwarf galaxies, including Draco, adopting both the widely used Navarro-Frenk-White (NFW) profile and observationally motivated axisymmetric density profiles. For four of the selected dwarfs (Sextans, Carina, Sculptor and Fornax) axisymmetric mass models suggest a cored density profile rather than the commonly adopted cusped profile. We found that upper limits on the annihilation cross section for some of these dwarfs are significantly higher than the ones achieved using an NFW profile. Therefore, upper limits in the literature obtained using cusped profiles like the NFW might have been overestimated. Our results eventually show that it is extremely important to use observationally motivated density profiles going beyond the usu...

  9. Joint analysis of deposition fluxes and atmospheric concentrations of inorganic nitrogen and sulphur compounds predicted by six chemistry transport models in the frame of the EURODELTAIII project (United States)

    Vivanco, M. G.; Bessagnet, B.; Cuvelier, C.; Theobald, M. R.; Tsyro, S.; Pirovano, G.; Aulinger, A.; Bieser, J.; Calori, G.; Ciarelli, G.; Manders, A.; Mircea, M.; Aksoyoglu, S.; Briganti, G.; Cappelletti, A.; Colette, A.; Couvidat, F.; D'Isidoro, M.; Kranenburg, R.; Meleux, F.; Menut, L.; Pay, M. T.; Rouïl, L.; Silibello, C.; Thunis, P.; Ung, A.


    all the campaigns, except for the 2006 campaign. This points to a low efficiency in the wet deposition of oxidized nitrogen for these models, especially with regards to the scavenging of nitric acid, which is the main driver of oxidized N deposition for all the models. CHIMERE, LOTOS-EUROS and EMEP agree better with the observations for both wet deposition and air concentration of oxidized nitrogen, although CHIMERE seems to overestimate wet deposition in the summer period. This requires further investigation, as the gas-particle equilibrium seems to be biased towards the gas phase (nitric acid) for this model. In the case of MINNI, the frequent underestimation of wet deposition combined with an overestimation of atmospheric concentrations for the three pollutants indicates a low efficiency of the wet deposition processes. This can be due to several reasons, such as an underestimation of scavenging ratios, large vertical concentration gradients (resulting in small concentrations at cloud height) or a poor parameterization of clouds. Large differences between models were also found for the estimates of dry deposition. However, the lack of suitable measurements makes it impossible to assess model performance for this process. These uncertainties should be addressed in future research, since dry deposition contributes significantly to the total deposition for the three deposited species, with values in the same range as wet deposition for most of the models, and with even higher values for some of them, especially for reduced nitrogen.

  10. 我国抵押品价值高估风险的博弈分析%Analysis on the Risk of Overestimate Collateral in China:A Game Theory Perspective

    Institute of Scientific and Technical Information of China (English)

    苟莹; 孙英隽


    In order to guard against borrower's indirectly manipulating assessment report, a dynamic game model with incomplete information was established to analyze the influential factors of game behavior and the existence conditions of game equilibrium in the case of two stakeholders influencing each other. The results show that there are four influential factors on the bank's optimal decision and four influential factors on the high-risk borrower's optimal decision. Finally, the reexamination mechanism should be adopted in assessment,at the same time, the borrower's delegation model should be translated into the bank's delegation model. Through these measures the healthy and sustainable development for credit market can be promoted.%为了防范借款人利用主动高估对评估报告的间接操纵行为,建立关于借款人和银行的不完全信息动态博弈模型,分析在借款人与银行两个直接利益相关者互相影响的情况下,其博弈行为的影响因素和博弈均衡的存在条件.研究表明:银行的决策受到借款人的高估收益、正常评估收益、高估成本、被发现高估后的损失这4个因素的影响;借款人的决策受到高风险借款人的概率、低风险借款人的概率、银行复审后的收益、银行因高估受到的损失这4个因素的影响.最后,提出银行应当引入抵押品评估复审机制,并且实施“银行委托评估”的模式来降低抵押品价值高估的风险.

  11. Vitronectin significantly influences prognosis in osteosarcoma. (United States)

    Shi, Kai; Lan, Rui-Long; Tao, Xuan; Wu, Chao-Yang; Hong, Hai-Feng; Lin, Jian-Hua


    Vitronectin (Vn), a multifunctional adhesive protein, is found in association with tumor progression, angiogenesis and metastasis in a variety of (human) tumors. But no studies concerning its correlation to osteosarcoma prognosis were found. Hence, we aimed to investigate the prognostic value of Vitronectin (Vn) in osteosarcoma. Here, we studied the expression of VN in the tumor tissues from 67 patients with osteosarcoma and 20 patients with osteochondroma using immunohistochemistry and estimated the effects of VN expression in osteosarcoma on progression-free survival (PFS) and overall survival (OS) using the Kaplan-Meier curve and COX proportional hazards regression model. Increased expression of VN in osteosarcoma tissue compared to no VN expression in osteochondroma tissue was shown in immunohistochemical assay. No associations were observed between VN expression and osteosarcoma patients' gender (P = 0.675), age (P = 0.813), tumor size (P = 0.436), histologic subtype (P = 0.0.543) or tumor location (P = 0.456). Univariate survival analysis demonstrated significant correlations of high VN expression with shorter PFS (P = 0.002) and OS (P = 0.001); multivariate survival analysis revealed high VN expression as a significant independent prognostic indicator for shorter PFS (HR 2.788, P = 0.003) and OS (HR2.817, P = 0.003). In conclusion, the high expression of VN in tumor cells independently indicated poor clinical prognosis in patients with osteosarcoma, other than large tumor size and non-neoadjuvant chemoradiotherapy, suggesting that VN may serve as a potential therapeutic target in osteosarcoma.

  12. Explanation of Significant Differences Between Models used to Assess Groundwater Impacts for the Disposal of Greater-Than-Class C Low-Level Radioactive Waste and Greater-Than-Class C-Like Waste Environmental Impact Statement (DOE/EIS-0375-D) and the

    Energy Technology Data Exchange (ETDEWEB)

    Annette Schafer; Arthur S. Rood; A. Jeffrey Sondrup


    Models have been used to assess the groundwater impacts to support the Draft Environmental Impact Statement for the Disposal of Greater-Than-Class C (GTCC) Low-Level Radioactive Waste and GTCC-Like Waste (DOE-EIS 2011) for a facility sited at the Idaho National Laboratory and the Environmental Assessment for the INL Remote-Handled Low-Level Waste Disposal Project (INL 2011). Groundwater impacts are primarily a function of (1) location determining the geologic and hydrologic setting, (2) disposal facility configuration, and (3) radionuclide source, including waste form and release from the waste form. In reviewing the assumptions made between the model parameters for the two different groundwater impacts assessments, significant differences were identified. This report presents the two sets of model assumptions and discusses their origins and implications for resulting dose predictions. Given more similar model parameters, predicted doses would be commensurate.

  13. Inverse agonism and its therapeutic significance

    Directory of Open Access Journals (Sweden)

    Gurudas Khilnani


    Full Text Available A large number of G-protein-coupled receptors (GPCRs show varying degrees of basal or constitutive activity. This constitutive activity is usually minimal in natural receptors but is markedly observed in wild type and mutated (naturally or induced receptors. According to conventional two-state drug receptor interaction model, binding of a ligand may initiate activity (agonist with varying degrees of positive intrinsic activity or prevent the effect of an agonist (antagonist with zero intrinsic activity. Inverse agonists bind with the constitutively active receptors, stabilize them, and thus reduce the activity (negative intrinsic activity. Receptors of many classes (α-and β-adrenergic, histaminergic, GABAergic, serotoninergic, opiate, and angiotensin receptors have shown basal activity in suitable in vitro models. Several drugs that have been conventionally classified as antagonists (β-blockers, antihistaminics have shown inverse agonist effects on corresponding constitutively active receptors. Nearly all H 1 and H 2 antihistaminics (antagonists have been shown to be inverse agonists. Among the β-blockers, carvedilol and bucindolol demonstrate low level of inverse agonism as compared to propranolol and nadolol. Several antipsychotic drugs (D 2 receptors antagonist, antihypertensive (AT 1 receptor antagonists, antiserotoninergic drugs and opioid antagonists have significant inverse agonistic activity that contributes partly or wholly to their therapeutic value. Inverse agonism may also help explain the underlying mechanism of beneficial effects of carvedilol in congestive failure, naloxone-induced withdrawal syndrome in opioid dependence, clozapine in psychosis, and candesartan in cardiac hypertrophy. Understanding inverse agonisms has paved a way for newer drug development. It is now possible to develop agents, which have only desired therapeutic value and are devoid of unwanted adverse effect. Pimavanserin (ACP-103, a highly selective 5-HT

  14. Comparison of simulated forest soil response to acid deposition reduction with two models of differing complexity

    Directory of Open Access Journals (Sweden)

    J. P. Mol-Dijkstra


    Full Text Available Great effort has been dedicated to developing soil acidification models for use on different scales. This paper focuses on the changes in model performance of a site scale soil acidification model (NUCSAM and a national to European scale soil acidification model (SMART 2. This was done to gain insight into the effects of model simplification. Because these models aim to predict the response to reduction in acid deposition, these models must be tested under such circumstances. A straightforward calibration and validation of the regional model, however, is hampered by lack of observations over a sufficient time period. Consequently, NUCSAM was calibrated and validated to a manipulation experiment involving reduced acid deposition in the Speuld forest, the Netherlands. SMART 2 was then used with calibrated input data from NUCSAM. The acid deposition was excluded by a roof beneath the canopy. The roofed area consists of a plot receiving pristine deposition levels of nitrogen (N and sulphur (S and a control plot receiving ambient deposition. NUCSAM was calibrated on the ambient plot, followed by a validation of both models on the pristine plot. Both models predicted soil solution concentrations within the 95% confidence interval of the observed responses for both the ambient plot and the pristine plot at 90 cm depth. Despite the large seasonal and vertical (spatial variation in soil solution chemistry, the trends in annual flux- weighted soil solution chemistry, as predicted by SMART 2 and NUCSAM, corresponded well.The annual leaching fluxes below the root zone were also similar although differences exist for the topsoil. For the topsoil, NUCSAM simulated the nutrients and acid related constituents better than SMART 2. Both models overestimated the ammonium (NH4 concentration at 10 cm depth. SMART 2 underestimated calcium and magnesium (BC2+ concentration at 10 depth, whereas NUCSAM overestimated BC2+ concentration at 90 cm depth. NUCSAM predicted

  15. Numerical modelling of Glacial Lake Outburst Floods using physically based dam-breach models (United States)

    Westoby, M. J.; Brasington, J.; Glasser, N. F.; Hambrey, M. J.; Reynolds, J. M.; Hassan, M. A. A. M.


    The rapid development and instability of moraine-dammed proglacial lakes is increasing the potential for the occurrence of catastrophic Glacial Lake Outburst Floods (GLOFs) in high-mountain regions. Advanced, physically-based numerical dam-breach models represent an improvement over existing methods for the derivation of breach outflow hydrographs. However, significant uncertainty surrounds the initial parameterisation of such models, and remains largely unexplored. We use a unique combination of numerical dam-breach and two-dimensional hydrodynamic modelling, employed with a Generalised Likelihood Uncertainty Estimation (GLUE) framework to quantify the degree of equifinality in dam-breach model output for the reconstruction of the failure of Dig Tsho, Nepal. Monte Carlo analysis was used to sample the model parameter space, and morphological descriptors of the moraine breach were used to evaluate model performance. Equifinal breach morphologies were produced by parameter ensembles associated with differing breach initiation mechanisms, including overtopping waves and mechanical failure of the dam face. The material roughness coefficient was discovered to exert a dominant influence over model performance. Percentile breach hydrographs derived from cumulative distribution function hydrograph data under- or overestimated total hydrograph volume and were deemed to be inappropriate for input to hydrodynamic modelling. Our results support the use of a Total Variation Diminishing solver for outburst flood modelling, which was found to be largely free of numerical instability and flow oscillation. Routing of scenario-specific optimal breach hydrographs revealed prominent differences in the timing and extent of inundation. A GLUE-based method for constructing likelihood-weighted maps of GLOF inundation extent, flow depth, and hazard is presented, and represents an effective tool for communicating uncertainty and equifinality in GLOF hazard assessment. However, future

  16. Clinical significance of MET in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Mikito; Inokuchi; Sho; Otsuki; Yoshitaka; Fujimori; Yuya; Sato; Masatoshi; Nakagawa; Kazuyuki; Kojima


    Chemotherapy has become the global standard treatment for patients with metastatic or unresectable gastric cancer(GC),although outcomes remain unfavorable.Many molecular-targeted therapies inhibiting signaling pathways of various tyrosine kinase receptors have been developed,and monoclonal antibodies targeting human epidermal growth factor receptor 2 or vascular endothelial growth factor receptor 2 have become standard therapy for GC.Hepatocyte growth factor and its receptor,c-MET(MET),play key roles in tumor growth through activated signaling pathways from receptor in GC cells.Genomic amplification of MET leads to the aberrant activation found in GC tumors and is related to survival in patients with GC.This review discusses the clinical significance of MET in GC and examines MET as a potential therapeutic target in patients with GC.Preclinical studies in animal models have shown that MET antibodies or smallmolecule MET inhibitors suppress tumor-cell proliferation and tumor progression in MET-amplified GC cells.These drugs are now being evaluated in clinical trials as treatments for metastatic or unresectable GC.

  17. Object caching in corvids: incidence and significance. (United States)

    Jacobs, Ivo F; Osvath, Mathias; Osvath, Helena; Mioduszewska, Berenika; von Bayern, Auguste M P; Kacelnik, Alex


    Food caching is a paramount model for studying relations between cognition, brain organisation and ecology in corvids. In contrast, behaviour towards inedible objects is poorly examined and understood. We review the literature on object caching in corvids and other birds, and describe an exploratory study on object caching in ravens, New Caledonian crows and jackdaws. The captive adult birds were presented with an identical set of novel objects adjacent to food. All three species cached objects, which shows the behaviour not to be restricted to juveniles, food cachers, tool-users or individuals deprived of cacheable food. The pattern of object interaction and caching did not mirror the incidence of food caching: the intensely food caching ravens indeed showed highest object caching incidence, but the rarely food caching jackdaws cached objects to similar extent as the moderate food caching New Caledonian crows. Ravens and jackdaws preferred objects with greater sphericity, but New Caledonian crows preferred stick-like objects (similar to tools). We suggest that the observed object caching might have been expressions of exploration or play, and deserves being studied in its own right because of its potential significance for tool-related behaviour and learning, rather than as an over-spill from food-caching research. This article is part of a Special Issue entitled: CO3 2013. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Phenotypic plasticity: molecular mechanisms and adaptive significance. (United States)

    Kelly, Scott A; Panhuis, Tami M; Stoehr, Andrew M


    Phenotypic plasticity can be broadly defined as the ability of one genotype to produce more than one phenotype when exposed to different environments, as the modification of developmental events by the environment, or as the ability of an individual organism to alter its phenotype in response to changes in environmental conditions. Not surprisingly, the study of phenotypic plasticity is innately interdisciplinary and encompasses aspects of behavior, development, ecology, evolution, genetics, genomics, and multiple physiological systems at various levels of biological organization. From an ecological and evolutionary perspective, phenotypic plasticity may be a powerful means of adaptation and dramatic examples of phenotypic plasticity include predator avoidance, insect wing polymorphisms, the timing of metamorphosis in amphibians, osmoregulation in fishes, and alternative reproductive tactics in male vertebrates. From a human health perspective, documented examples of plasticity most commonly include the results of exercise, training, and/or dieting on human morphology and physiology. Regardless of the discipline, phenotypic plasticity has increasingly become the target of a plethora of investigations with the methodological approaches utilized ranging from the molecular to whole organsimal. In this article, we provide a brief historical outlook on phenotypic plasticity; examine its potential adaptive significance; emphasize recent molecular approaches that provide novel insight into underlying mechanisms, and highlight examples in fishes and insects. Finally, we highlight examples of phenotypic plasticity from a human health perspective and underscore the use of mouse models as a powerful tool in understanding the genetic architecture of phenotypic plasticity.

  19. Modeling the impact of prostate edema on LDR brachytherapy: a Monte Carlo dosimetry study based on a 3D biphasic finite element biomechanical model. (United States)

    Mountris, K A; Bert, J; Noailly, J; Aguilera, A Rodriguez; Valeri, A; Pradier, O; Schick, U; Promayon, E; Ballester, M A Gonzalez; Troccaz, J; Visvikis, D


    Prostate volume changes due to edema occurrence during transperineal permanent brachytherapy should be taken under consideration to ensure optimal dose delivery. Available edema models, based on prostate volume observations, face several limitations. Therefore, patient-specific models need to be developed to accurately account for the impact of edema. In this study we present a biomechanical model developed to reproduce edema resolution patterns documented in the literature. Using the biphasic mixture theory and finite element analysis, the proposed model takes into consideration the mechanical properties of the pubic area tissues in the evolution of prostate edema. The model's computed deformations are incorporated in a Monte Carlo simulation to investigate their effect on post-operative dosimetry. The comparison of Day1 and Day30 dosimetry results demonstrates the capability of the proposed model for patient-specific dosimetry improvements, considering the edema dynamics. The proposed model shows excellent ability to reproduce previously described edema resolution patterns and was validated based on previous findings. According to our results, for a prostate volume increase of 10-20% the Day30 urethra D10 dose metric is higher by 4.2%-10.5% compared to the Day1 value. The introduction of the edema dynamics in Day30 dosimetry shows a significant global dose overestimation identified on the conventional static Day30 dosimetry. In conclusion, the proposed edema biomechanical model can improve the treatment planning of transperineal permanent brachytherapy accounting for post-implant dose alterations during the planning procedure.

  20. A generalized Forchheimer radial flow model for constant-rate tests (United States)

    Liu, Ming-Ming; Chen, Yi-Feng; Zhan, Hongbin; Hu, Ran; Zhou, Chuang-Bing


    Models used for data interpretation of constant-rate tests (CRTs) are commonly derived with the assumption of Darcian flow in an idealized integer flow dimension, where the non-Darcian nature of fluid flow and the complexity of flow geometry are disregarded. In this study, a Forchheimer's law-based analytical model is proposed with the assumption of buildup (or drawdown) decomposition for characterizing the non-Darcian flow in a generalized radial formation where the flow dimension n may become non-integer. The proposed model immediately reduces to Barker's (1988) model for Darcian flow in the generalized radial formation and to Mathias et al.'s (2008) model for non-Darcian flow in a two-dimensional confined aquifer. A comparison with numerical simulations shows that the proposed model behaves well at late times for flow dimension n > 1.5. The proposed model is finally applied for data interpretation of the constant-rate pumping tests performed at Ploemeur (Le Borgne et al., 2004), showing that the intrinsic hydraulic conductivity of formations will be underestimated and the specific storage will be overestimated if the non-Darcian effect is ignored. The proposed model is an extension of the generalized radial flow (GRF) model based on Forchheimer's law, which would be of significance for data interpretation of CRTs in aquifers of complex flow geometry in which non-Darcian flow occurs.

  1. General slip regime permeability model for gas flow through porous media (United States)

    Zhou, Bo; Jiang, Peixue; Xu, Ruina; Ouyang, Xiaolong


    A theoretical effective gas permeability model was developed for rarefied gas flow in porous media, which holds over the entire slip regime with the permeability derived as a function of the Knudsen number. This general slip regime model (GSR model) is derived from the pore-scale Navier-Stokes equations subject to the first-order wall slip boundary condition using the volume-averaging method. The local closure problem for the volume-averaged equations is studied analytically and numerically using a periodic sphere array geometry. The GSR model includes a rational fraction function of the Knudsen number which leads to a limit effective permeability as the Knudsen number increases. The mechanism for this behavior is the viscous fluid inner friction caused by converging-diverging flow channels in porous media. A linearization of the GSR model leads to the Klinkenberg equation for slightly rarefied gas flows. Finite element simulations show that the Klinkenberg model overestimates the effective permeability by as much as 33% when a flow approaches the transition regime. The GSR model reduces to the unified permeability model [F. Civan, "Effective correlation of apparent gas permeability in tight porous media," Transp. Porous Media 82, 375 (2010)] for the flow in the slip regime and clarifies the physical significance of the empirical parameter b in the unified model.

  2. When the Jeans don't fit: How stellar feedback drives stellar kinematics and complicates dynamical modeling in low-mass galaxies

    CERN Document Server

    El-Badry, Kareem; Geha, Marla; Quataert, Eliot; Hopkins, Philip F; Kereš, Dusan; Chan, T K; Faucher-Giguère, Claude-André


    In low-mass galaxies, stellar feedback can drive gas outflows that generate non-equilibrium fluctuations in the gravitational potential. Using cosmological zoom-in baryonic simulations from the Feedback in Realistic Environments (FIRE) project, we investigate how these fluctuations affect stellar kinematics and the reliability of Jeans dynamical modeling in low-mass galaxies. We find that stellar velocity dispersion and anisotropy profiles fluctuate significantly over the course of galaxies' starburst cycles. We therefore predict an observable correlation between star formation rate and stellar kinematics: dwarf galaxies with higher recent star formation rates should have systemically higher stellar velocity dispersions. This prediction provides an observational test of the role of stellar feedback in regulating both stellar and dark-matter densities in dwarf galaxies. We find that Jeans modeling, which treats galaxies as virialized systems in dynamical equilibrium, overestimates a galaxy's dynamical mass dur...

  3. SWAT Modeling for Depression-Dominated Areas: How Do Depressions Manipulate Hydrologic Modeling?

    Directory of Open Access Journals (Sweden)

    Mohsen Tahmasebi Nasab


    Full Text Available Modeling hydrologic processes for depression-dominated areas such as the North American Prairie Pothole Region is complex and reliant on a clear understanding of dynamic filling-spilling-merging-splitting processes of numerous depressions over the surface. Puddles are spatially distributed over a watershed and their sizes, storages, and interactions vary over time. However, most hydrologic models fail to account for these dynamic processes. Like other traditional methods, depressions are filled as a required preprocessing step in the Soil and Water Assessment Tool (SWAT. The objective of this study was to facilitate hydrologic modeling for depression-dominated areas by coupling SWAT with a Puddle Delineation (PD algorithm. In the coupled PD-SWAT model, the PD algorithm was utilized to quantify topographic details, including the characteristics, distribution, and hierarchical relationships of depressions, which were incorporated into SWAT at the hydrologic response unit (HRU scale. The new PD-SWAT model was tested for a large watershed in North Dakota under real precipitation events. In addition, hydrologic modeling of a small watershed was conducted under two extreme high and low synthetic precipitation conditions. In particular, the PD-SWAT was compared against the regular SWAT based on depressionless DEMs. The impact of depressions on the hydrologic modeling of the large and small watersheds was evaluated. The simulation results for the large watershed indicated that SWAT systematically overestimated the outlet discharge, which can be attributed to the failure to account for the hydrologic effects of depressions. It was found from the PD-SWAT modeling results that at the HRU scale surface runoff initiation was significantly delayed due to the threshold control of depressions. Under the high precipitation scenario, depressions increased the surface runoff peak. However, the low precipitation scenario could not fully fill depressions to reach

  4. Parametric bootstrap for testing model fitting in the proportional hazards framework: an application to the survival analysis of Bruna dels Pirineus beef calves. (United States)

    Casellas, J; Tarrés, J; Piedrafita, J; Varona, L


    Given that correct assumptions on the baseline survival function are determinant for the validity of further inferences, specific tools to test the fit of a model to real data become essential in proportional hazards models. In this sense, we have proposed a parametric bootstrap to test the fit of survival models. Monte Carlo simulations are used to generate new data sets from the estimates obtained through the assumed models, and then bootstrap intervals can be established for the survival function along the time space studied. Significant fitting deficiencies are revealed when the real survival function is not included within the bootstrap interval. We tested this procedure in a survival data set of Bruna dels Pirineus beef calves, assuming 4 parametric models (exponential, Weibull, exponential time-dependent, Weibull time-dependent) and the Cox's semiparametric model. Fitting deficiencies were not observed for the Cox's model and the exponential time-dependent model, whereas the Weibull time-dependent model suffered from moderate overestimation at different ages. Thus, the exponential time-dependent model appears to be preferable because of its correct fit for survival data of beef calves and its smaller computational and time requirements. Exponential and Weibull models were completely rejected due to the continuous over- and underestimation of the survival probability reported. Results here highlighted the flexibility of parametric models with time-dependent effects, achieving a fit comparable to nonparametric models.

  5. The Real World Significance of Performance Prediction (United States)

    Pardos, Zachary A.; Wang, Qing Yang; Trivedi, Shubhendu


    In recent years, the educational data mining and user modeling communities have been aggressively introducing models for predicting student performance on external measures such as standardized tests as well as within-tutor performance. While these models have brought statistically reliable improvement to performance prediction, the real world…

  6. Multi-resolution Changes in the Spatial Extent of Perennial Arctic Alpine Snow and Ice Fields with Potential Archaeological Significance in the Central Brooks Range, Alaska (United States)

    Tedesche, M. E.; Freeburg, A. K.; Rasic, J. T.; Ciancibelli, C.; Fassnacht, S. R.


    Perennial snow and ice fields could be an important archaeological and paleoecological resource for Gates of the Arctic National Park and Preserve in the central Brooks Range mountains of Arctic Alaska. These features may have cultural significance, as prehistoric artifacts may be frozen within the snow and ice. Globally significant discoveries have been made recently as ancient artifacts and animal dung have been found in melting alpine snow and ice patches in the Southern Yukon and Northwest Territories in Canada, the Wrangell mountains in Alaska, as well as in other areas. These sites are melting rapidly, which results in quick decay of biological materials. The summer of 2015 saw historic lows in year round snow cover extent for most of Alaska. Twenty mid to high elevation sites, including eighteen perennial snow and ice fields, and two glaciers, were surveyed in July 2015 to quantify their areal extent. This survey was accomplished by using both low flying aircraft (helicopter), as well as with on the ground in-situ (by foot) measurements. By helicopter, visual surveys were conducted within tens of meters of the surface. Sites visited by foot were surveyed for extent of snow and ice coverage, melt water hydrologic parameters and chemistry, and initial estimates of depths and delineations between snow, firn, and ice. Imagery from both historic aerial photography and from 5m resolution IKONOS satellite information were correlated with the field data. Initial results indicate good agreement in permanent snow and ice cover between field surveyed data and the 1985 to 2011 Landsat imagery-based Northwest Alaska snow persistence map created by Macander et al. (2015). The most deviation between the Macander et al. model and the field surveyed results typically occurred as an overestimate of perennial extent on the steepest aspects. These differences are either a function of image classification or due to accelerated ablation rates in perennial snow and ice coverage

  7. A sedação e analgesia de crianças submetidas à ventilação mecânica estariam sendo superestimadas? Sedation and analgesia in children submitted to mechanical ventilation could be overestimated?

    Directory of Open Access Journals (Sweden)

    Ana Sfoggia


    to mechanical ventilation in a regional pediatric intensive care unit during a 12-month period. To compare the use of these drugs among clinical and surgical patients, as well evaluate the influence of the length of use on the average daily doses and on the incidence of abstinence syndrome. METHODS: this cohort study was performed from April 2001 to March 2002, involving children (1 month old to 15 years old submitted to the mechanical ventilation with a tracheal tube for a period longer than 12 hours and who were successfully extubated (dead patients and those who required reintubation were excluded from the study. A team of professionals not involved with the patient's assistance performed a daily collection of all data up to the 28th day under mechanical ventilation (maximum length of follow up for those who remain longer under mechanical ventilation. The main outcome was the infusion doses of morphine, fentanyl, ketamine and midazolam administered at 12 AM (considering this dose as the average dose for that day. The diagnosis of abstinence syndrome was based on the chart revision (recorded diagnosis or based on the specific antagonist treatment used and in an interview with the assistant physician on the following days after the extubation. This study was approved by the Ethics and Scientific Committee of the HSL-PUCRS. RESULTS: 127 children were eligible for this study, but only 124 patients were analyzed (16.0+29-5 months old; 58% male; 92 defined as clinical patients and 32 as surgical patients. An average of 1.7 sedative-analgesic infusion per patient a day was used in the whole group (without difference between clinical and surgical groups. Morphine and fentanyl were the most common drugs infused in both groups (fentanyl was preferred for the clinical group and morphine for the surgical group. The mean length of infusion was different (p<0.01 between clinical and surgical patients (6.8 and 3.9 days, respectively. After the 7th day, there was a significant

  8. 48 CFR 2110.7003 - Significant events. (United States)


    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Significant events. 2110..., AND OTHER PURCHASE DESCRIPTIONS Contract Specifications 2110.7003 Significant events. The contractor is required to inform the contracting officer of all significant events....

  9. Creating Significant Learning Experiences across Disciplines (United States)

    Levine, Laura E.; Fallahi, Carolyn R.; Nicoll-Senft, Joan M.; Tessier, Jack T.; Watson, Cheryl L.; Wood, Rebecca M.


    The purpose of this study was to use Fink's (2003) taxonomy of significant learning to redesign courses and assess student learning. Significant improvements were found across the semester for students in the six courses, but there were differences in which taxa showed improvement in each course. The meta-analysis showed significant, positive…

  10. Modelling growth and bioaccumulation of Polychlorinated biphenyls in common sole ( Solea solea) (United States)

    Eichinger, M.; Loizeau, V.; Roupsard, F.; Le Guellec, A. M.; Bacher, C.


    Experiments were performed on juvenile sole in controlled conditions in the aim of understanding how the biology of common sole may affect the accumulation and dilution of Polychlorinated biphenyls (PCBs). The fish were raised in optimal conditions and divided into two tanks: one control tank and one PCB tank. 4 PCB congeners were added to food for 3 months in the PCB tank; the soles were subsequently fed unspiked food for 3 months. Growth (length and weight) and PCB concentrations were monitored in both tanks and juvenile sole growth was not significantly affected by PCBs in our experimental conditions. We used the Dynamic Energy Budget (DEB) theory to model sole biology and paid special attention to model calibration through the wide use of data from the literature. The model accurately reproduced fish growth in both tanks. We coupled a bioaccumulation model to reproduce the concentration dynamics of the 4 PCB congeners used. This model did not require additional calibration and was dependent solely on the growth model and PCB concentrations in food. The bioaccumulation model accurately simulated PCB accumulation in fish, but overestimated PCB concentrations in fish during the dilution phase. This may suggest that in addition to PCB dilution due to growth, PCB concentrations decreased due to other PCB elimination mechanisms. Finally, we discussed potential improvements to the model and its future applications.

  11. Modeling the impact of prostate edema on LDR brachytherapy: a Monte Carlo dosimetry study based on a 3D biphasic finite element biomechanical model (United States)

    Mountris, K. A.; Bert, J.; Noailly, J.; Rodriguez Aguilera, A.; Valeri, A.; Pradier, O.; Schick, U.; Promayon, E.; Gonzalez Ballester, M. A.; Troccaz, J.; Visvikis, D.


    Prostate volume changes due to edema occurrence during transperineal permanent brachytherapy should be taken under consideration to ensure optimal dose delivery. Available edema models, based on prostate volume observations, face several limitations. Therefore, patient-specific models need to be developed to accurately account for the impact of edema. In this study we present a biomechanical model developed to reproduce edema resolution patterns documented in the literature. Using the biphasic mixture theory and finite element analysis, the proposed model takes into consideration the mechanical properties of the pubic area tissues in the evolution of prostate edema. The model’s computed deformations are incorporated in a Monte Carlo simulation to investigate their effect on post-operative dosimetry. The comparison of Day1 and Day30 dosimetry results demonstrates the capability of the proposed model for patient-specific dosimetry improvements, considering the edema dynamics. The proposed model shows excellent ability to reproduce previously described edema resolution patterns and was validated based on previous findings. According to our results, for a prostate volume increase of 10–20% the Day30 urethra D10 dose metric is higher by 4.2%–10.5% compared to the Day1 value. The introduction of the edema dynamics in Day30 dosimetry shows a significant global dose overestimation identified on the conventional static Day30 dosimetry. In conclusion, the proposed edema biomechanical model can improve the treatment planning of transperineal permanent brachytherapy accounting for post-implant dose alterations during the planning procedure.

  12. On combining significances. Some trivial examples

    CERN Document Server

    Krasnikov, N V


    For Poisson distribution $Pois(n, \\lambda)$ with $\\lambda \\gg 1$, $n \\gg 1$ we propose to determine significance as $S = \\frac{n_{obs}-\\lambda}{\\sqrt{\\lambda}}$. The significance $S$ coincides up to sign with often used significance. For experiments which measure the same quantities the natural but not unique rule for significance combining is $S_{comb}(S_1, S_2) = \\frac{S_1\\sigma_1+S_2\\sigma_2}{\\sqrt{\\sigma^2_1+\\sigma^2_2}}$, where $\\sigma_1$ and $\\sigma_2$ are variations. We also propose the rule for significances combining for the case with systematic errors.

  13. World Urbanization Prospects: an alternative to the UN model of projection compatible with the mobility transition theory

    Directory of Open Access Journals (Sweden)

    Philippe Bocquier


    Full Text Available This paper proposes to critically examine the United Nations projections on urbanisation. Both the estimates of current trends based on national data and the method of projection are evaluated. The theory of mobility transition is used as an alternative hypothesis. Projections are proposed using a polynomial model and compared to the UN projections, which are based on a linear model. The conclusion is that UN projections may overestimate the urban population for the year 2030 by almost one billion, or 19% in relative term. The overestimation would be particularly more pronounced for developing countries and may exceed 30% in Africa, India and Oceania.

  14. Improving ecophysiological simulation models to predict the impact of elevated atmospheric CO2 concentration on crop productivity

    NARCIS (Netherlands)

    Yin, X.


    Background - Process-based ecophysiological crop models are pivotal in assessing responses of crop productivity and designing strategies of adaptation to climate change. Most existing crop models generally over-estimate the effect of elevated atmospheric [CO2], despite decades of experimental resear

  15. How do we make sense of significance?

    DEFF Research Database (Denmark)

    Lyhne, Ivar; Kørnøv, Lone


    Determination of significance is widely recognised as an important step in environmental assessment (EA) processes. The prescriptive literature and guidance on significance determination is comprehensive within the field of EA, whereas descriptive and explorative studies of how we go about making...... sense, or construct meaning, of actions to determine significance are few. This article makes use of sense-making theory to explore how sense-making among EA researchers and practitioners influence significance determination. Focus is on the situation when persons have their first look at information...... about a strategic choice and as part of this make their initial judgement of significance. An experiment is designed and conducted to investigate how persons make sense of a specific case and determine significance in a screening and scoping context. The experiment indicates patterns in the test persons...

  16. Implementation of a Surface Runoff Model with Horton and Dunne Mechanisms into the Regional Climate Model RegCM_NCC

    Institute of Scientific and Technical Information of China (English)

    SHI Xueli; XIE Zhenghui; LIU Yiming; YANG Hongwei


    A surface runoff parameterization scheme that dynamically represents both Horton and Dunne runoff generation mechanisms within a model grid cell together with a consideration of the subgrid-scale soil heterogeneity, is implemented into the National Climate Center regional climate model (RegCM_NCC). The effects of the modified surface runoff scheme on RegCM_NCC performance are tested with an abnormal heavy rainfall process which occurred in summer 1998. Simulated results show that the model with the original surface runoff scheme (noted as CTL) basically captures the spatial pattern of precipitation, circulation and land surface variables, but generally overestimates rainfall compared to observations. The model with the new surface runoff scheme (noted as NRM) reasonably reproduces the distribution pattern of various variables and effectively diminishes the excessive precipitation in the CTL. The processes involved in the improvement of NRM-simulated rainfall may be as follows: with the new surface runoff scheme, simulated surface runoff is larger, soil moisture and evaporation (latent heat flux) are decreased, the available water into the atmosphere is decreased; correspondingly, the atmosphere is drier and rainfall is decreased through various processes. Therefore, the implementation of the new runoff scheme into the RegCM_NCC has a significant effect on results at not only the land surface, but also the overlying atmosphere.

  17. Natural stochasticity vs. management effort: use of year-to-year variance for disentangling significance of two mutually confounding factors affecting water quality of a Norwegian cold dimictic lake

    Directory of Open Access Journals (Sweden)

    A. T. Romarheim


    Full Text Available Natural stochasticity can pose challenges in managing the quality of the environment, or hinder understanding of the system structure. It is problematic because unfavourable stochastic event cancels the costly management effort and because favourable stochastic event overestimates success of the management effort. This paper presents a variance-based modelling method that can be used to quantify the extent to which the natural stochasticity can affect the target environment. We use a case study of a lake water quality assessment in a Norwegian lake of Årungen, together with a lake model MyLake, in order to present the method, and how this method could assist in answering scientific and managerial questions. Specifically, the case study's goal was to disentangle the respective significance of nutrient loading (management and weather (the confounding natural stochasticity. Many scientifically and managerially relevant understandings have been revealed. For example, variation in runoff volume was most prevalent during autumn and winter, while variation in phosphorus inflow was most extensive from late winter to early spring. Thermal related properties in the lake were mostly determined by weather conditions, whereas loading was the most important factor for phytoplankton biomass and water transparency. Mild winters and greater inputs of suspended matter and phosphorus were followed by increased phytoplankton biomass and light attenuation. These findings suggest also that future changes in the global climate may have important implications for local water management decision-making. The present method of disentangling mutually confounding factors is not limited to lake water quality studies and therefore should provide certain utility in other application field of modelling.

  18. Central Region Regionally Ecological Significant Areas (United States)

    Minnesota Department of Natural Resources — This is an analysis of regionally significant Terrestrial and Wetland Ecological Areas in the seven county metropolitan area. Individual forest, grassland and...

  19. Regionally Significant Ecological Areas - MLCCS derived 2008 (United States)

    Minnesota Department of Natural Resources — This is an analysis of regionally significant Terrestrial and Wetland Ecological Areas in the seven county metropolitan area. Individual forest, grassland and...

  20. Why Terrorists Overestimate the Odds of Victory 

    Directory of Open Access Journals (Sweden)

    Max Abrahms


    Full Text Available Terrorism is puzzling behavior for political scientists. On one hand, terrorist attacks generally hail from the politically aggrieved. On the other hand, a growing body of scholarship finds the tactic politically counterproductive. Unlike guerrilla attacks on military targets, terrorist attacks on civilian targets lower the odds of governments making  concessions. This article proposes and tests a psychological theory to account for why militant groups engage in terrorism, given the political costs of attacking civilians.

  1. Allergy to antibiotics in children: an overestimated problem. (United States)

    Esposito, Susanna; Castellazzi, Luca; Tagliabue, Claudia; Principi, Nicola


    Antibiotics are the most prescribed drugs for children, and a relevant number of prescriptions are associated with the emergence of adverse events. Allergic reactions are the most frequently reported adverse events, with an incidence of up to 10% of all prescriptions. However, literature analysis has shown that allergy to antibiotics is generally overdiagnosed in children because in most cases the diagnosis is based only on the clinical history without a full allergy work-up. Consequently, children are often improperly deprived of narrow-spectrum antibiotics because of a suspected allergy to these drugs. β-Lactams, mainly penicillins, are more frequently involved as a cause of allergy to antibiotics, although allergic problems are reported for most of the antibiotic classes. Accurate diagnosis is essential for a precise definition of determination of allergy to a given drug. Diagnosis has to be based on history, laboratory tests and, when possible, on in vitro and drug provocation tests. Unfortunately, the allergological work-up is well structured only for β-lactam antibiotics, whereas for non-β-lactams few studies are available, with very limited experience in children. The main aim of this paper is to discuss the real relevance of allergy to antibiotics in children in order to provide physicians with the knowledge needed to establish an appropriate diagnostic allergy work-up and to make better use of antibiotic therapy.

  2. Auto-reactive T cells revised. Overestimation based on methodology?

    DEFF Research Database (Denmark)

    Thorlacius-Ussing, Gorm; Sørensen, Jesper F; Wandall, Hans H


    Autoreactive T cells have been identified in most autoimmune diseases and recently even in healthy individuals. Similar, T cells that recognize either wild-type or tumorspecific tumor antigens have been increasingly reported to develop spontaneously in cancer patients. This insight has become...... possible mainly due to novel immunoassays which have revolutionized the discovery of rare antigen specific T cells. At present, the major dogma that explains this increasing number of reports of autoreactive T cells is that autoreactive T cells are counteracted by CD4+CD25+ regulatory T (Treg) cells...... in vivo, in particular in healthy individuals, whereas dysfunction in Tregs or Treg responsiveness may unmask the autoreactive T cell responses in patients with autoimmune diseases. However, studies that identify autoreactive T cells are usually performed by culturing T cells with antigen presenting cells...

  3. Overestimating hybrid layer quality in polished adhesive/dentin interfaces. (United States)

    Wang, Yong; Spencer, Paulette


    The most popular techniques for determining the quality of the hybrid layer (HL) have relied on morphologic characterization of the polished adhesive/dentin (a/d) interfaces before and after acid-bleach chemical treatment. Using these techniques, the existence of smooth, acid-resistant layers has been consistently reported for most adhesive systems. The purpose of this study was to determine whether popular specimen preparation techniques that include polishing and acid-bleach treatment modify the a/d interface, mask the complexity of the HL, and lead to inaccurate assessment of the quality of the HL. To understand the impact of specimen preparation techniques on the morphology of the resin-dentin interface, polished and unpolished specimens from the same tooth were closely compared after different acid-bleach chemical treatment procedures. Two one-bottle adhesives, that is, 3M Single Bond and Pulpdent UNO, exhibiting distinct differences in hydrophilic/hydrophobic composition, were used in this investigation. Using specimens from the same tooth, the effect of chemical treatments on the morphology of the resin-dentin interdiffusion zone and the differences in the morphology of polished and unpolished specimens after these same treatments were studied with scanning electron microscopy. It was shown that conventional specimen preparation techniques that include polishing and acid-bleach treatment can adversely affect and even obscure the structural detail of the a/d interface in specimens that possess a porous HL. The results indicated that the Pulpdent UNO/dentin interface had better quality than the 3M Single Bond/dentin interface. The difference in the quality of HL can be attributed to factors such as compositional differences that impact the adhesive interaction with water, that is present within the substrate during wet bonding. The inability of the conventional acid-bleach procedure to reveal the differences in the scanning electron microscopy interfacial morphology was overcome in this investigation by using a multistep technique. Copyright 2004 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 735-746, 2004

  4. Do global change experiments overestimate impacts on terrestrial ecosystems?

    DEFF Research Database (Denmark)

    Leuzinger, Sebastian; Luo, Yiqi; Beier, Claus


    In recent decades, many climate manipulation experiments have investigated biosphere responses to global change. These experiments typically examined effects of elevated atmospheric CO2, warming or drought (driver variables) on ecosystem processes such as the carbon and water cycle (response...... of the responses to decline with higher-order interactions, longer time periods and larger spatial scales. This means that on average, both positive and negative global change impacts on the biosphere might be dampened more than previously assumed....

  5. Overestimation of hypoglycemia in infants with a high hematocrit

    NARCIS (Netherlands)

    Kemperman, Hans; van Solinge, Wouter W; de Vooght, Karen MK


    Background: In neonates, hypoglycemia is an emergency condition requiring urgent treatment. Therefore, rapid and reliable blood glucose measurements are necessary. However, this step has been proven difficult because of both analytical and preanalytical variables. In our children's hospital, we inci

  6. The Elephant in the Room: Spatial Heterogeneity and the Uncertainty of Measurements and Models (United States)

    Alfieri, J. G.; Kustas, W. P.; Prueger, J. H.; Agam, N.; Neale, C. M. U.; Evett, S. R.


    Variations in surface conditions can significantly influence the exchange of heat and moisture between the land and atmosphere. As a result, measurements of surface fluxes using disparate methods not only may differ, they may fail to represent the surrounding landscape due to localized differences in surface conditions. To illustrate this, data collected over adjacent cotton fields during the Bushland Evapotranspiration and Agricultural Remote Sensing Experiment (BEAREX08) will be used. The evapotranspiration (ET) within each field was determined via lysimetry (LY), mass balance using neutron probe (NP) data, and a pair of eddy covariance (EC) systems. A comparison of the cumulative ET from each field showed that ET from LY was 20% to 25% greater than that derived from NP and 10% to 15% greater than those from EC. Additionally, the cumulative flux for the two fields collected using the same approach differed by 5% to 10%. These discrepancies can be explained, in large part, by the variations in vegetation density within the two fields. Not only were there substantial variations in the leaf area index (LAI) within the source areas of the different measurement systems - for example, the LAI within LY was, on average, 0.4 m2 m-2 greater than the LAI within the source area of NP - there were also significant differences in the LAI between the fields as a whole. The cumulative ET output by the remote sensing-based Two-Source Energy Balance (TSEB) model was also compared to the cumulative ET from each of the three measurement approaches. Depending on which measurement technique is used, the model either underestimated the moisture flux by approximately 5%, in the case of LY, or overestimated the flux by nearly 20%, in the case of NP. Comparison of the model output with EC data also indicated that the model overestimated ET, in this case, by approximately 10%. Clearly, the choice of which dataset is used to validate the model significantly effects the conclusions drawn

  7. ANAM vs. NAM: Is the difference significant?

    NARCIS (Netherlands)

    Hammel, S.; Eijk, A.M.J. van; Tsintikidis, D.


    The Navy Aerosol Model (NAM, available in MODTRAN) is widely used as a tool to assess the aerosol extinction in the marine atmospheric surface layer. NAM was built as a regression model in the 1980s to represent the aerosol extinction at deck height as a function of the meteorological conditions. Th

  8. Coarse-graining polymer solutions: A critical appraisal of single- and multi-site models (United States)

    D'Adamo, G.; Menichetti, R.; Pelissetto, A.; Pierleoni, C.


    We critically discuss and review the general ideas behind single- and multi-site coarse-grained (CG) models as applied to macromolecular solutions in the dilute and semi-dilute regime. We first consider single-site models with zero-density and density-dependent pair potentials. We highlight advantages and limitations of each option in reproducing the thermodynamic behavior and the large-scale structure of the underlying reference model. As a case study we consider solutions of linear homopolymers in a solvent of variable quality. Secondly, we extend the discussion to multi-component systems presenting, as a test case, results for mixtures of colloids and polymers. Specifically, we found the CG model with zero-density potentials to be unable to predict fluid-fluid demixing in a reasonable range of densities for mixtures of colloids and polymers of equal size. For larger colloids, the polymer volume fractions at which phase separation occurs are largely overestimated. CG models with density-dependent potentials are somewhat less accurate than models with zero-density potentials in reproducing the thermodynamics of the system and, although they present a phase separation, they significantly underestimate the polymer volume fractions along the binodal. Finally, we discuss a general multi-site strategy, which is thermodynamically consistent and fully transferable with the number of sites, and that allows us to overcome most of the limitations discussed for single-site models.

  9. Multi-model evaluation of short-lived pollutant distributions over East Asia during summer 2008

    Directory of Open Access Journals (Sweden)

    B. Quennehen


    Full Text Available The ability of six global and one regional model to reproduce distributions of tropospheric ozone and its precursors, as well as aerosols over Asia in summer 2008 is evaluated using satellite and in-situ observations. Whilst ozone precursors (NO2 and CO are generally underestimated by the models in the troposphere, surface NO2 concentrations are overestimated, suggesting that emissions of NOx are too high. Ozone integrated columns and vertical profiles are generally well modeled, but the global models face difficulties simulating the ozone gradient at the surface between urban and rural environments, pointing to the need to increase model resolution. The accuracy of simulated aerosol patterns over eastern China and northern India varies between the models, and although most of the models reproduce the observed pollution features over eastern China, significant biases are noted in the magnitude of optical properties (aerosol optical depth, aerosol backscatter. These results have important implications for accurate prediction of pollution episodes affecting air quality and the radiative effects of these short-lived climate pollutants over Asia.

  10. Coupled atmospheric, land surface, and subsurface modeling: Exploring water and energy feedbacks in three-dimensions (United States)

    Davison, Jason H.; Hwang, Hyoun-Tae; Sudicky, Edward A.; Lin, John C.


    Human activities amplified by climate change pose a significant threat to the sustainability of water resources. Coupled climate-hydrologic simulations commonly predict these threats by combining shallow 1-D land surface models (LSMs) with traditional 2-D and 3-D hydrology models. However, these coupled models limit the moisture and energy-feedback dynamics to the shallow near-surface. This paper presents a novel analysis by applying an integrated variably-saturated subsurface/surface hydrology and heat transport model, HydroGeoSphere (HGS), as a land surface model (LSM). Furthermore, this article demonstrates the coupling of HGS to a simple 0-D atmospheric boundary layer (ABL) model. We then applied our coupled HGS-ABL model to three separate test cases and reproduced the strong correlation between the atmospheric energy balance to the depth of the groundwater table. From our simulations, we found that conventional LSMs may overestimate surface temperatures for extended drought periods because they underestimate the heat storage in the groundwater zone. Our final test case of the atmospheric response to drought conditions illustrated that deeper roots buffered the atmosphere better than shallow roots by maintaining higher latent heat fluxes, lower sensible heat fluxes, and lower surface and atmospheric temperatures.

  11. Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model (United States)

    Madenjian, Charles P.; David, Solomon R.; Pothoven, Steven A.


    We evaluated the performance of the Wisconsin bioenergetics model for lake trout Salvelinus namaycush that were fed ad libitum in laboratory tanks under regimes of low activity and high activity. In addition, we compared model performance under two different model algorithms: (1) balancing the lake trout energy budget on day t based on lake trout energy density on day t and (2) balancing the lake trout energy budget on day t based on lake trout energy density on day t + 1. Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when algorithm 1 was used and that the degree of underestimation was similar for the two activity levels. In contrast, model performance substantially improved when using algorithm 2, as no detectable bias was found in model predictions of consumption for inactive fish and only a slight degree of overestimation was detected for active fish. The energy budget was accurately balanced by using algorithm 2 but not by using algorithm 1. Based on the results of this study, we recommend the use of algorithm 2 to estimate food consumption by fish in the field. Our study results highlight the importance of accurately accounting for changes in fish energy density when balancing the energy budget; furthermore, these results have implications for the science of evaluating fish bioenergetics model performance and for more accurate estimation of food consumption by fish in the field when fish energy density undergoes relatively rapid changes.

  12. Fluid-Structure Interaction in Abdominal Aortic Aneurysm: Effect of Modeling Techniques

    Directory of Open Access Journals (Sweden)

    Shengmao Lin


    Full Text Available In this work, the impact of modeling techniques on predicting the mechanical behaviors of abdominal aortic aneurysm (AAA is systematically investigated. The fluid-structure interaction (FSI model for simultaneously capturing the transient interaction between blood flow dynamics and wall mechanics was compared with its simplified techniques, that is, computational fluid dynamics (CFD or computational solid stress (CSS model. Results demonstrated that CFD exhibited relatively smaller vortexes and tends to overestimate the fluid wall shear stress, compared to FSI. On the contrary, the minimal differences in wall stresses and deformation were observed between FSI and CSS models. Furthermore, it was found that the accuracy of CSS prediction depends on the applied pressure profile for the aneurysm sac. A large pressure drop across AAA usually led to the underestimation of wall stresses and thus the AAA rupture. Moreover, the assumed isotropic AAA wall properties, compared to the anisotropic one, will aggravate the difference between the simplified models with the FSI approach. The present work demonstrated the importance of modeling techniques on predicting the blood flow dynamics and wall mechanics of the AAA, which could guide the selection of appropriate modeling technique for significant clinical implications.

  13. Fluid-Structure Interaction in Abdominal Aortic Aneurysm: Effect of Modeling Techniques. (United States)

    Lin, Shengmao; Han, Xinwei; Bi, Yonghua; Ju, Siyeong; Gu, Linxia


    In this work, the impact of modeling techniques on predicting the mechanical behaviors of abdominal aortic aneurysm (AAA) is systematically investigated. The fluid-structure interaction (FSI) model for simultaneously capturing the transient interaction between blood flow dynamics and wall mechanics was compared with its simplified techniques, that is, computational fluid dynamics (CFD) or computational solid stress (CSS) model. Results demonstrated that CFD exhibited relatively smaller vortexes and tends to overestimate the fluid wall shear stress, compared to FSI. On the contrary, the minimal differences in wall stresses and deformation were observed between FSI and CSS models. Furthermore, it was found that the accuracy of CSS prediction depends on the applied pressure profile for the aneurysm sac. A large pressure drop across AAA usually led to the underestimation of wall stresses and thus the AAA rupture. Moreover, the assumed isotropic AAA wall properties, compared to the anisotropic one, will aggravate the difference between the simplified models with the FSI approach. The present work demonstrated the importance of modeling techniques on predicting the blood flow dynamics and wall mechanics of the AAA, which could guide the selection of appropriate modeling technique for significant clinical implications.

  14. Fluid-Structure Interaction in Abdominal Aortic Aneurysm: Effect of Modeling Techniques (United States)

    Lin, Shengmao; Han, Xinwei; Bi, Yonghua; Ju, Siyeong


    In this work, the impact of modeling techniques on predicting the mechanical behaviors of abdominal aortic aneurysm (AAA) is systematically investigated. The fluid-structure interaction (FSI) model for simultaneously capturing the transient interaction between blood flow dynamics and wall mechanics was compared with its simplified techniques, that is, computational fluid dynamics (CFD) or computational solid stress (CSS) model. Results demonstrated that CFD exhibited relatively smaller vortexes and tends to overestimate the fluid wall shear stress, compared to FSI. On the contrary, the minimal differences in wall stresses and deformation were observed between FSI and CSS models. Furthermore, it was found that the accuracy of CSS prediction depends on the applied pressure profile for the aneurysm sac. A large pressure drop across AAA usually led to the underestimation of wall stresses and thus the AAA rupture. Moreover, the assumed isotropic AAA wall properties, compared to the anisotropic one, will aggravate the difference between the simplified models with the FSI approach. The present work demonstrated the importance of modeling techniques on predicting the blood flow dynamics and wall mechanics of the AAA, which could guide the selection of appropriate modeling technique for significant clinical implications. PMID:28321413

  15. Determining the clinical significance of monoclonal gammopathy of undetermined significance: a SEER-Medicare population analysis. (United States)

    Go, Ronald S; Gundrum, Jacob D; Neuner, Joan M


    Clinical guidelines have recommended annual follow-up examinations of most patients with monoclonal gammopathy of undetermined significance (MGUS); however, evidence supporting this practice is lacking. We performed a population-based study to examine the patterns of disease presentation and outcomes of patients with multiple myeloma, Waldenström macroglobulinemia, and lymphoplasmacytic lymphoma (monoclonal gammopathy-associated malignancies) comparing those with or without a previous MGUS follow-up examination. Patients with monoclonal gammopathy-associated malignancy from 1994 through 2007 were identified using the Surveillance, Epidemiology, and End Results-Medicare linked database and divided into 2 cohorts: those with follow-up (MGUS follow-up examination preceding the diagnosis) and those with no follow-up (no such follow-up examination). We compared the outcomes, including the rates of major complications at cancer diagnosis (acute kidney injury, cord compression, dialysis use, fracture, and hypercalcemia) and survival using propensity score adjustment and Cox proportional hazard models. All statistical tests were 2-sided. Of the 17,457 study patients, 6% had undergone MGUS follow-up. After multivariable modeling, the follow-up group had significantly fewer major complications at diagnosis (odds ratio 0.68; 95% confidence interval [CI], 0.57-0.80) and better disease-specific (median, 38 vs. 29 months, P < .001; hazard ratio [HR] 0.85; 95% CI, 0.76-0.94) and overall (median, 23 vs. 19 months, P < .001; HR 0.87; 95% CI, 0.80-0.95) survival. Patients with MGUS follow-up preceding the diagnosis of a monoclonal gammopathy-associated malignancy can experience fewer major complications and have longer survival than those without such follow-up examinations. Future studies replicating our findings in the non-Medicare population and determining the optimal schedule and cost-effectiveness of MGUS follow-up are warranted. Copyright © 2015 Elsevier Inc. All rights

  16. Asymptotic Distributions for Tests of Combined Significance. (United States)

    Becker, Betsy Jane

    This paper discusses distribution theory and power computations for four common "tests of combined significance." These tests are calculated using one-sided sample probabilities or p values from independent studies (or hypothesis tests), and provide an overall significance level for the series of results. Noncentral asymptotic sampling…

  17. The Vernier Caliper and Significant Figures. (United States)

    Oberhofer, E. S.


    Misconceptions occur because the caliper is often read with the same significant figures as a meter stick; however, the precision of the vernier caliper is greater than the precision of a meter stick. Clarification of scale reading, precision of both tools, and significant figures are discussed. (JN)

  18. Indian Ocean sea surface salinity variations in a coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Vinayachandran, P.N.; Nanjundiah, Ravi S. [Indian Institute of Science, Centre for Atmospheric and Oceanic Sciences, Bangalore (India)


    The variability of the sea surface salinity (SSS) in the Indian Ocean is studied using a 100-year control simulation of the Community Climate System Model (CCSM 2.0). The monsoon-driven seasonal SSS pattern in the Indian Ocean, marked by low salinity in the east and high salinity in the west, is captured by the model. The model overestimates runoff into the Bay of Bengal due to higher rainfall over the Himalayan-Tibetan regions which drain into the Bay of Bengal through Ganga-Brahmaputra rivers. The outflow of low-salinity water from the Bay of Bengal is too strong in the model. Consequently, the model Indian Ocean SSS is about 1 less than that seen in the climatology. The seasonal Indian Ocean salt balance obtained from the model is consistent with the analysis from climatological data sets. During summer, the large freshwater input into the Bay of Bengal and its redistribution decide the spatial pattern of salinity tendency. During winter, horizontal advection is the dominant contributor to the tendency term. The interannual variability of the SSS in the Indian Ocean is about five times larger than that in coupled model simulations of the North Atlantic Ocean. Regions of large interannual standard deviations are located near river mouths in the Bay of Bengal and in the eastern equatorial Indian Ocean. Both freshwater input into the ocean and advection of this anomalous flux are responsible for the generation of these anomalies. The model simulates 20 significant Indian Ocean Dipole (IOD) events and during IOD years large salinity anomalies appear in the equatorial Indian Ocean. The anomalies exist as two zonal bands: negative salinity anomalies to the north of the equator and positive to the south. The SSS anomalies for the years in which IOD is not present and for ENSO years are much weaker than during IOD years. Significant interannual SSS anomalies appear in the Indian Ocean only during IOD years. (orig.)

  19. Indian Ocean sea surface salinity variations in a coupled model (United States)

    Vinayachandran, P. N.; Nanjundiah, Ravi S.


    The variability of the sea surface salinity (SSS) in the Indian Ocean is studied using a 100-year control simulation of the Community Climate System Model (CCSM 2.0). The monsoon-driven seasonal SSS pattern in the Indian Ocean, marked by low salinity in the east and high salinity in the west, is captured by the model. The model overestimates runoff into the Bay of Bengal due to higher rainfall over the Himalayan-Tibetan regions which drain into the Bay of Bengal through Ganga-Brahmaputra rivers. The outflow of low-salinity water from the Bay of Bengal is too strong in the model. Consequently, the model Indian Ocean SSS is about 1 less than that seen in the climatology. The seasonal Indian Ocean salt balance obtained from the model is consistent with the analysis from climatological data sets. During summer, the large freshwater input into the Bay of Bengal and its redistribution decide the spatial pattern of salinity tendency. During winter, horizontal advection is the dominant contributor to the tendency term. The interannual variability of the SSS in the Indian Ocean is about five times larger than that in coupled model simulations of the North Atlantic Ocean. Regions of large interannual standard deviations are located near river mouths in the Bay of Bengal and in the eastern equatorial Indian Ocean. Both freshwater input into the ocean and advection of this anomalous flux are responsible for the generation of these anomalies. The model simulates 20 significant Indian Ocean Dipole (IOD) events and during IOD years large salinity anomalies appear in the equatorial Indian Ocean. The anomalies exist as two zonal bands: negative salinity anomalies to the north of the equator and positive to the south. The SSS anomalies for the years in which IOD is not present and for ENSO years are much weaker than during IOD years. Significant interannual SSS anomalies appear in the Indian Ocean only during IOD years.

  20. The thresholds for statistical and clinical significance

    DEFF Research Database (Denmark)

    Jakobsen, Janus Christian; Gluud, Christian; Winkel, Per


    threshold if the trial is stopped early or if interim analyses have been conducted; (4) adjust the confidence intervals and the P-values for multiplicity due to number of outcome comparisons; and (5) assess clinical significance of the trial results. CONCLUSIONS: If the proposed five-step procedure...... not reflect the probability of getting a result assuming an alternative hypothesis to the null hypothesis is true. Second, a confidence interval or a P-value showing significance may be caused by multiplicity. Third, statistical significance does not necessarily result in clinical significance. Therefore......, assessment of intervention effects in randomised clinical trials deserves more rigour in order to become more valid. METHODS: Several methodologies for assessing the statistical and clinical significance of intervention effects in randomised clinical trials were considered. Balancing simplicity...

  1. Discussion on Establishment of Cervical Vertigo Animal Models from Theory of "Musculoskeletal Force Stability" and Analysis It's Significance in Research of Manipulation Mechanism%基于筋骨力学平衡探讨颈性眩晕动物模型的构建及在手法干预中的意义

    Institute of Scientific and Technical Information of China (English)

    范志勇; 赖瑞美; 查和萍; 田宁; 粟漩; 王卫强; 谢兵


    It is urgently necessary for cervical vertigo animal models in the study of osteology and traumatology of traditional Chinese medicine.Analysis theory of traditional Chinese and western medicine with musculoskeletal force stability.Discussing mutual evidence with establishment of cervical vertigo animal models and pathogenesis research from musculoskeletal mechanics imbalance,and analysis it's significance in the research of manipulation mechanism.%颈性眩晕动物模型是当前中医骨伤基础研究所急需的,通过分析筋与骨力学平衡的中西医理论,从筋骨力学失衡角度探讨颈性眩晕模型构建及病变机制的研究是相互佐证的,并分析其在手法干预机制研究中的意义.

  2. Identification of sequence motifs significantly associated with antisense activity

    Directory of Open Access Journals (Sweden)

    Peek Andrew S


    Full Text Available Abstract Background Predicting the suppression activity of antisense oligonucleotide sequences is the main goal of the rational design of nucleic acids. To create an effective predictive model, it is important to know what properties of an oligonucleotide sequence associate significantly with antisense activity. Also, for the model to be efficient we must know what properties do not associate significantly and can be omitted from the model. This paper will discuss the results of a randomization procedure to find motifs that associate significantly with either high or low antisense suppression activity, analysis of their properties, as well as the results of support vector machine modelling using these significant motifs as features. Results We discovered 155 motifs that associate significantly with high antisense suppression activity and 202 motifs that associate significantly with low suppression activity. The motifs range in length from 2 to 5 bases, contain several motifs that have been previously discovered as associating highly with antisense activity, and have thermodynamic properties consistent with previous work associating thermodynamic properties of sequences with their antisense activity. Statistical analysis revealed no correlation between a motif's position within an antisense sequence and that sequences antisense activity. Also, many significant motifs existed as subwords of other significant motifs. Support vector regression experiments indicated that the feature set of significant motifs increased correlation compared to all possible motifs as well as several subsets of the significant motifs. Conclusion The thermodynamic properties of the significantly associated motifs support existing data correlating the thermodynamic properties of the antisense oligonucleotide with antisense efficiency, reinforcing our hypothesis that antisense suppression is strongly associated with probe/target thermodynamics, as there are no enzymatic

  3. Sensitivity analysis of WRF model PBL schemes in simulating boundary-layer variables in southern Italy: An experimental campaign (United States)

    Avolio, E.; Federico, S.; Miglietta, M. M.; Lo Feudo, T.; Calidonna, C. R.; Sempreviva, A. M.


    The sensitivity of boundary layer variables to five (two non-local and three local) planetary boundary-layer (PBL) parameterization schemes, available in the Weather Research and Forecasting (WRF) mesoscale meteorological model, is evaluated in an experimental site in Calabria region (southern Italy), in an area characterized by a complex orography near the sea. Results of 1 km × 1 km grid spacing simulations are compared with the data collected during a measurement campaign in summer 2009, considering hourly model outputs. Measurements from several instruments are taken into account for the performance evaluation: near surface variables (2 m temperature and relative humidity, downward shortwave radiation, 10 m wind speed and direction) from a surface station and a meteorological mast; vertical wind profiles from Lidar and Sodar; also, the aerosol backscattering from a ceilometer to estimate the PBL height. Results covering the whole measurement campaign show a cold and moist bias near the surface, mostly during daytime, for all schemes, as well as an overestimation of the downward shortwave radiation and wind speed. Wind speed and direction are also verified at vertical levels above the surface, where the model uncertainties are, usually, smaller than at the surface. A general anticlockwise rotation of the simulated flow with height is found at all levels. The mixing height is overestimated by all schemes and a possible role of the simulated sensible heat fluxes for this mismatching is investigated. On a single-case basis, significantly better results are obtained when the atmospheric conditions near the measurement site are dominated by synoptic forcing rather than by local circulations. From this study, it follows that the two first order non-local schemes, ACM2 and YSU, are the schemes with the best performance in representing parameters near the surface and in the boundary layer during the analyzed campaign.

  4. Simulation and Projection of Blocking Highs in Key Regions of the Eurasia by CMIP5 Models (United States)

    Li, Y.


    Previous studies generally hold viewpoint that CMIP5 models underestimate blocking frequency and predict decreasing trend of blockings in 21st century in North Hemisphere (NH). However, regional blocking has its own features, which is different from blockings in NH as a whole. Focusing on three key regions in Eurasia-Ural, Baikal, and Okhotsk where blockings significantly influence weather and climate of East Asia, historical simulations were analyzed to evaluate the performance of the CMIP5 models, and possible changes in the first half 21st century were then predicted using the RCP 4.5 and RCP 8.5 pathways. Comparison with NCEP/NCAR reanalysis (NNR) data revealed that instantaneous blocking frequencies are underestimated in the Ural and Baikal in the whole year and in Okhotsk in summer, but are overestimated in Okhotsk in winter. Overall, the CMIP5 models could largely reproduce character of instantaneous blocking frequency in the Eurasia, with a better performance in winter than in summer. Blocking episodes frequency in the Ural and Baikal is underestimated by most the 13 CMIP5 models, especially the short duration blocking episodes, and simulated superiorly in winter to in summer. However, modeled blocking episodes frequency is near to observed value in summer but overestimated in winter in Okhotsk. Model projections of instantaneous blocking frequency for the first half 21st century (2016-2065) shows that the RCP 4.5 projection yields a significant increasing frequency during January-May, decreasing frequency during June-August, and a little increasing frequency during September- December. The RCP 8.5 projection presents similar case to RCP 4.5 projection, but indicating more remarkable decreasing trend. Blocking episodes frequency of the multi-model ensemble mean obviously decreases in the Ural and Baikal (especially blocking episodes with short duration) and increase a little in Okhotsk in the first half 21st century. For blocking episodes with long duration

  5. Traffic Emissions of Radical Precursors and Related Species as Observed and Modeled at an Urban Highway Junction in Houston/Texas (United States)

    Rappenglück, Bernhard; Lubertino, Graciela


    Nitrous acid (HONO) and formaldehyde (HCHO) are important precursors for radicals and are believed to favor ozone formation significantly. Traffic emissions data for both compounds is scarce. Here we report results from continuous ambient air measurements of HONO, HCHO, carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NO/NO2/NOx), and peroxyacyl nitrates (PANs) taken at an Highway Junction in Houston/Texas from July 15 - October 15, 2009. The observational data was compared to emission estimates from currently available mobile emissions models (MOBILE6; MOVES). Observations indicated a molar CO versus NOx ratio of 6.01±0.15 (r2 = 0.91), which is in agreement with other field studies. Both, MOBILE6 and MOVES, overestimate this emission ratio by 92% and 24%, respectively. For HCHO/CO an overall slope of 3.14±0.14 g HCHO / kg CO was observed. While MOBILE6 largely underestimates this ratio by 77%, MOVES calculates somewhat higher HCHO/CO ratios (1.87) than MOBILE6, but is still significantly lower than the observed ratio. MOVES shows high HCHO/CO ratios during the early morning hours due to heavy duty diesel off-network emissions. The differences of the modeled CO/NOx and HCHO/CO ratios are largely due to higher NOx and HCHO emissions in MOVES (30% and 57%, respectively, increased from MOBILE6 for 2009), as CO emissions were about the same in both models. The observed HONO/NOx emission ratio is around 0.017±0.0009 kg HONO / kg NOx which is twice as high as in MOVES. The observed NO2/NOx emission ratio is around 0.16±0.01 kg NO2 / kg NOx, which is a bit more than 50% higher than in MOVES. MOVES overestimates the CO/CO2 emission ratio by a factor of 3 compared with the observations, which is 0.0033±0.0002 kg CO / kg CO2. This as well as CO/NOx overestimation is coming from light duty gasoline vehicles.

  6. Mining significant semantic locations from GPS data

    DEFF Research Database (Denmark)

    Cao, Xin; Cong, Gao; Jensen, Christian S.


    With the increasing deployment and use of GPS-enabled devices, massive amounts of GPS data are becoming available. We propose a general framework for the mining of semantically meaningful, significant locations, e.g., shopping malls and restaurants, from such data. We present techniques capable...... of extracting semantic locations from GPS data. We capture the relationships between locations and between locations and users with a graph. Significance is then assigned to locations using random walks over the graph that propagates significance among the locations. In doing so, mutual reinforcement between...

  7. Mining significant semantic locations from GPS data

    DEFF Research Database (Denmark)

    Cao, Xin; Cong, Gao; Jensen, Christian S.


    With the increasing deployment and use of GPS-enabled devices, massive amounts of GPS data are becoming available. We propose a general framework for the mining of semantically meaningful, significant locations, e.g., shopping malls and restaurants, from such data. We present techniques capable...... of extracting semantic locations from GPS data. We capture the relationships between locations and between locations and users with a graph. Significance is then assigned to locations using random walks over the graph that propagates significance among the locations. In doing so, mutual reinforcement between...

  8. Discovering the Significance of Scientific Design Practice

    DEFF Research Database (Denmark)

    Pries-Heje, Jan; Baskerville, Richard


    This paper discusses and defines the achievement of significance in design science research. We review the values and processes of old-science and how this mode of science attacks the complexity of scientific knowledge production through analysis. We then explain how new-science attacks...... the complexity of scientific knowledge production through synthesis. The work argues that significance of the new-science contribution in design science can be obfuscated when wrapped in old-science. This understanding helps reveal how new-science, such as design science research, constitutes its significance...

  9. Hydrological and Climatic Significance of Martian Deltas (United States)

    Di Achille, G.; Vaz, D. A.


    We a) review the geomorphology, sedimentology, and mineralogy of the martian deltas record and b) present the results of a quantitative study of the hydrology and sedimentology of martian deltas using modified version of terrestrial model Sedflux.

  10. Connectivity in air transport networks: an assessment of models and applications

    NARCIS (Netherlands)

    G. Burghouwt; R. Redondi


    This paper classifies and compares eight different connectivity models employed in air transport literature and applies them to European airports. Traditional size-based measures tend to underestimate the accessibility of small airports and overestimate the centrality of large airports. Small airpor

  11. Biases in human sequential predictions as a consequence of incorrect world models, noise and limited memory

    NARCIS (Netherlands)

    Narain, D.; Beers, R.J. van; Smeets, J.B.J.


    Recent studies demonstrate that biases found in human behavior can be explained by rational agents that make incorrect generative-model assumptions. While predicting a sequence of uncorrelated events, humans are biased towards overestimating its serial correlation. We demonstrate how such biases may

  12. How do we make sense of significance?

    DEFF Research Database (Denmark)

    Lyhne, Ivar; Kørnøv, Lone


    sense, or construct meaning, of actions to determine significance are few. This article makes use of sense-making theory to explore how sense-making among EA researchers and practitioners influence significance determination. Focus is on the situation when persons have their first look at information...... about a strategic choice and as part of this make their initial judgement of significance. An experiment is designed and conducted to investigate how persons make sense of a specific case and determine significance in a screening and scoping context. The experiment indicates patterns in the test persons......' sense-making, including important differences in the way individuals screen and scope. These patterns concern what we notice, how fast we frame the choice, and when we are critical about the provided information. The indications provide a basis for reflections on practice and on how to organise EA...

  13. SIGWX Charts - High Level Significant Weather (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — High level significant weather (SIGWX) forecasts are provided for the en-route portion of international flights. NOAA's National Weather Service Aviation Center...

  14. Significant communities in large sparse networks

    CERN Document Server

    Mirshahvalad, Atieh; Derlen, Mattias; Rosvall, Martin


    Researchers use community-detection algorithms to reveal large-scale organization in biological and social networks, but community detection is useful only if the communities are significant and not a result of noisy data. To assess the statistical significance of the network communities, or the robustness of the detected structure, one approach is to perturb the network structure by removing links and measure how much the communities change. However, perturbing sparse networks is challenging because they are inherently sensitive; they shatter easily if links are removed. Here we propose a simple method to perturb sparse networks and assess the significance of their communities. We generate resampled networks by adding extra links based on local information, then we aggregate the information from multiple resampled networks to find a coarse-grained description of significant clusters. In addition to testing our method on benchmark networks, we use our method on the sparse network of the European Court of Just...

  15. SRS Process Facility Significance Fire Frequency

    Energy Technology Data Exchange (ETDEWEB)

    Sarrack, A.G. [Westinghouse Savannah River Company, AIKEN, SC (United States)


    This report documents the method and assumptions of a study performed to determine a site generic process facility significant fire initiator frequency and explains the proper way this value should be used.

  16. Fostering significant learning in graduate nursing education. (United States)

    Marrocco, Geraldine F


    Faculty who want to energize graduate students with creative classes that lead to long-lasting learning will benefit by designing course objectives, learning activities, and assessment tools using Fink's taxonomy of significant learning and Wiggins's insights on performance-based or educative assessments. Research shows that course designs relying on content-driven lectures and written examinations do not promote significant learning among adult learners. This article reviews six types of significant learning using Fink's taxonomy and examines Wiggins's "backward" approach to designing courses using performance-based assessments that gauge true learning and learning that promotes a lasting change. When designing courses, educators should ask: "What do I really want students to get out of this course?" The answers will direct the design of objectives, learning activities, and assessment tools. Designing graduate courses using Fink's taxonomy and Wiggins's backward approach can lead to significant learning to better prepare nurse practitioners for the future of health care. Copyright 2014, SLACK Incorporated.

  17. Significance of Studies of Stylistics and Rhetoric

    Institute of Scientific and Technical Information of China (English)



    Stylistics is a scientific study of style. It is a mode of encoding and decoding language and can be associated with various fields. In this paper,we talk about the great significances of stylistic and rhetoric studies. It refers to great help in expressing and understanding languages;in combining the linguistics and literary criticism and linguistics;great help in promoting and developing computer science and information technology;great significance in sharing heritage of human civilizations.

  18. Projected changes in surface solar radiation in CMIP5 global climate models and in EURO-CORDEX regional climate models for Europe (United States)

    Bartók, Blanka; Wild, Martin; Folini, Doris; Lüthi, Daniel; Kotlarski, Sven; Schär, Christoph; Vautard, Robert; Jerez, Sonia; Imecs, Zoltán


    The objective of the present work is to compare the projections of surface solar radiation (SSR) simulated by four regional climate models (CCLM, RCA4, WRF, ALADIN) with the respective fields of their ten driving CMIP5 global climate models. First the annual and seasonal SSR changes are examined in the regional and in the global climate models based on the RCP8.5 emission scenarios. The results show significant discrepancies between the projected SSR, the multi-model mean of RCMs indicates a decrease in SSR of -0.60 W/m2 per decade over Europe, while the multi-model mean of the associated GCMs used to drive the RCMs gives an increase in SSR of +0.39 W/m2 per decade for the period of 2006-2100 over Europe. At seasonal scale the largest differences appear in spring and summer. The different signs of SSR projected changes can be interpreted as the consequence of the different behavior of cloud cover in global and regional climate models. Cloudiness shows a significant decline in GCMs with -0.24% per decade which explains the extra income in SSR, while in case of the regional models no significant changes in cloudiness can be detected. The reduction of SSR in RCMs can be attributed to increasing atmospheric absorption in line with the increase of water vapor content. Both global and regional models overestimate SSR in absolute terms as compared to surface observations, in line with an underestimation of cloud cover. Regional models further have difficulties to adequately reproduce the observed trends in SSR over the past decades.

  19. Parametrization of activation based cardiac electrophysiology models using bidomain model simulations

    Directory of Open Access Journals (Sweden)

    Stender Birgit


    Full Text Available Eikonal models are useful to compute approximate solutions of cardiac excitation propagation in a computationally efficient way. In this work the underlying conduction velocities for different cell types were computed solving the classical bidomain model equations for planar wavefront propagation. It was further investigated how changes in the conductivity tensors within the bidomain model analytically correspond to changes in the conduction velocity. The error in the presence of local front curvature for the derived eikonal model parametrization were analyzed. The conduction velocity simulated based on the bidomain model was overestimated by a maximum of 10%.

  20. Can a stepwise steady flow computational fluid dynamics model reproduce unsteady particulate matter separation for common unit operations? (United States)

    Pathapati, Subbu-Srikanth; Sansalone, John J


    Computational fluid dynamics (CFD) is emerging as a model for resolving the fate of particulate matter (PM) by unit operations subject to rainfall-runoff loadings. However, compared to steady flow CFD models, there are greater computational requirements for unsteady hydrodynamics and PM loading models. Therefore this study examines if integrating a stepwise steady flow CFD model can reproduce PM separation by common unit operations loaded by unsteady flow and PM loadings, thereby reducing computational effort. Utilizing monitored unit operation data from unsteady events as a metric, this study compares the two CFD modeling approaches for a hydrodynamic separator (HS), a primary clarifier (PC) tank, and a volumetric clarifying filtration system (VCF). Results indicate that while unsteady CFD models reproduce PM separation of each unit operation, stepwise steady CFD models result in significant deviation for HS and PC models as compared to monitored data; overestimating the physical size requirements of each unit required to reproduce monitored PM separation results. In contrast, the stepwise steady flow approach reproduces PM separation by the VCF, a combined gravitational sedimentation and media filtration unit operation that provides attenuation of turbulent energy and flow velocity.

  1. Interhemispheric differences in seasonal cycles of tropospheric ozone in the marine boundary layer: Observation-model comparisons (United States)

    Derwent, Richard G.; Parrish, David D.; Galbally, Ian E.; Stevenson, David S.; Doherty, Ruth M.; Young, Paul J.; Shallcross, Dudley E.


    Marine boundary layer ozone seasonal cycles have been quantified by fitting the sum of two sine curves through monthly detrended observations taken at three stations: Mace Head, Ireland, and Trinidad Head, California, in the Northern Hemisphere and Cape Grim, Tasmania, in the Southern Hemisphere. The parameters defining the sine curve fits at these stations have been compared with those from a global Lagrangian chemistry-transport model and from 14 Atmospheric Chemistry Coupled Climate Model Intercomparison Project chemistry-climate models. Most models substantially overestimated the long-term average ozone levels at Trinidad Head, while they performed much better for Mace Head and Cape Grim. This led to an underestimation of the observed (North Atlantic inflow-North Pacific inflow) difference. The models generally underpredicted the magnitude of the fundamental term of the fitted seasonal cycle, most strongly at Cape Grim. The models more accurately reproduced the observed second harmonic terms compared to the fundamental terms at all stations. Significant correlations have been identified between the errors in the different models' estimates of the seasonal cycle parameters; these correlations may yield further insights into the causes of the model-measurement discrepancies.

  2. How significant is the ‘significant other’? Associations between significant others’ health behaviors and attitudes and young adults’ health outcomes

    Directory of Open Access Journals (Sweden)

    Berge Jerica M


    Full Text Available Abstract Background Having a significant other has been shown to be protective against physical and psychological health conditions for adults. Less is known about the period of emerging young adulthood and associations between significant others’ weight and weight-related health behaviors (e.g. healthy dietary intake, the frequency of physical activity, weight status. This study examined the association between significant others’ health attitudes and behaviors regarding eating and physical activity and young adults’ weight status, dietary intake, and physical activity. Methods This study uses data from Project EAT-III, a population-based cohort study with emerging young adults from diverse ethnic and socioeconomic backgrounds (n = 1212. Logistic regression models examining cross-sectional associations, adjusted for sociodemographics and health behaviors five years earlier, were used to estimate predicted probabilities and calculate prevalence differences. Results Young adult women whose significant others had health promoting attitudes/behaviors were significantly less likely to be overweight/obese and were more likely to eat ≥ 5 fruits/vegetables per day and engage in ≥ 3.5 hours/week of physical activity, compared to women whose significant others did not have health promoting behaviors/attitudes. Young adult men whose significant other had health promoting behaviors/attitudes were more likely to engage in ≥ 3.5 hours/week of physical activity compared to men whose significant others did not have health promoting behaviors/attitudes. Conclusions Findings suggest the protective nature of the significant other with regard to weight-related health behaviors of young adults, particularly for young adult women. Obesity prevention efforts should consider the importance of including the significant other in intervention efforts with young adult women and potentially men.

  3. Road traffic impact on urban water quality: a step towards integrated traffic, air and stormwater modelling. (United States)

    Fallah Shorshani, Masoud; Bonhomme, Céline; Petrucci, Guido; André, Michel; Seigneur, Christian


    Methods for simulating air pollution due to road traffic and the associated effects on stormwater runoff quality in an urban environment are examined with particular emphasis on the integration of the various simulation models into a consistent modelling chain. To that end, the models for traffic, pollutant emissions, atmospheric dispersion and deposition, and stormwater contamination are reviewed. The present study focuses on the implementation of a modelling chain for an actual urban case study, which is the contamination of water runoff by cadmium (Cd), lead (Pb), and zinc (Zn) in the Grigny urban catchment near Paris, France. First, traffic emissions are calculated with traffic inputs using the COPERT4 methodology. Next, the atmospheric dispersion of pollutants is simulated with the Polyphemus line source model and pollutant deposition fluxes in different subcatchment areas are calculated. Finally, the SWMM water quantity and quality model is used to estimate the concentrations of pollutants in stormwater runoff. The simulation results are compared to mass flow rates and concentrations of Cd, Pb and Zn measured at the catchment outlet. The contribution of local traffic to stormwater contamination is estimated to be significant for Pb and, to a lesser extent, for Zn and Cd; however, Pb is most likely overestimated due to outdated emissions factors. The results demonstrate the importance of treating distributed traffic emissions from major roadways explicitly since the impact of these sources on concentrations in the catchment outlet is underestimated when those traffic emissions are spatially averaged over the catchment area.

  4. Innovative trend significance test and applications (United States)

    Şen, Zekai


    Hydro-climatological time series might embed characteristics of past changes concerning climate variability in terms of shifts, cyclic fluctuations, and more significantly in the form of trends. Identification of such features from the available records is one of the prime tasks of hydrologists, climatologists, applied statisticians, or experts in related topics. Although there are different trend identification and significance tests in the literature, they require restrictive assumptions, which may not be existent in the structure of hydro-climatological time series. In this paper, a method is suggested with statistical significance test for trend identification in an innovative manner. This method has non-parametric basis without any restrictive assumption, and its application is rather simple with the concept of sub-series comparisons that are extracted from the main time series. The method provides privilege for selection of sub-temporal half periods for the comparison and, finally, generates trend on objective and quantitative manners. The necessary statistical equations are derived for innovative trend identification and statistical significance test application. The application of the proposed methodology is suggested for three time series from different parts of the world including Southern New Jersey annual temperature, Danube River annual discharge, and Tigris River Diyarbakir meteorology station annual total rainfall records. Each record has significant trend with increasing type in the New Jersey case, whereas in other two cases, decreasing trends exist.

  5. Meaning reconstruction in bereavement: sense and significance. (United States)

    Hibberd, Rachel


    Recently there has been growing empirical and theoretical attention to the role of meaning in grief along with increased recognition of the need for more sophisticated definitions of meaning. The present article highlights philosophical issues inherent in the study of meaning and grief reviews the place of meaning in current theories of grief and provides a brief overview of the ways that meaning has been operationalized by grief researchers, including sense-making, benefit finding, identity change, and purpose in life. It is argued that, in our focus on the ways mourners make sense of loss, we have neglected an important aspect of meaning: life significance. Life significance is the felt perception that some aspect of one's life experience "matters." The construct is explored as a potentially important outcome of bereavement; mourners may lose life significance along with their lost loved one, or they may develop new avenues to life significance as they confront mortality and rebuild shattered worldviews. Related literature, such as appreciation of life as a facet of posttraumatic growth, is surveyed for clues as to the role of life significance in grief. Suggestions for future study are offered.

  6. Biological significance and variation of endothelin-1 in the penis of rat model with abnormal phlegmatic syndrome%维医异常黏液质型阳痿病证大鼠模型阴茎组织中ET-1的改变及其生物学意义

    Institute of Scientific and Technical Information of China (English)

    毛吾兰·买买提依明; 张盼盼; 刘凤霞; 阿地力江·伊明; 木萨·艾麦尔; 薛志琴; 陈胜国


    目的:研究维医异常黏液质型阳痿病证大鼠模型阴茎组织中 ET-1的改变及其生物学意义。方法100只 SD大鼠经实验确认具有正常性功能后,10只作为正常对照组,其余90只作为造模组,采用湿寒性饲料和湿寒性环境条件下建立异常黏液质证候模型。造模20 w以后,通过交配和勃起实验从证候模型中筛选出阳痿病证模型,并将其分为病证模型组和病证药物反证组,未成阳痿的证候模型再随机分为证候模型组与证候药物反证组。药物干预2周后,取材,并对阴茎组织进行免疫组化染色,光镜下观察。结果证候模型组、病证模型组大鼠阴茎组织中 ET-1的表达均较正常对照组显著增高(P <0.05),各组织间差异均无统计学意义(P >0.05),而证候药物反证组和病证药物反证组 ET-1较证候模型组和病证模型组明显降低,但无统计学差异(P >0.05)。结论 ET-1表达水平升高可能是异常黏液质型阳痿病证重要的发病机制之一。%Objective To study the biological significance and variation of endothelin-1 expression in the pe-nis of rat model with impotence disease.Methods A total of 100 normal mature male SD rats were en-rolled in the study,and 10 of them were randomly chosen as the control group,the other 90 were treated with spinach and coriander diet in a cold and humid environment until the model of abnormal phlegmatic syndrome was established.After 20 weeks of diet treatment,they were divided into abnormal phlegmatic syndrome model group and pharmacological intervention group by APO erectile experiments and mating experiments.After 2 weeks of recovery treatment to the pharmacological intervention group,immunohis-tochemical stainingwas conducted in the penile tissue of all groups.Results Compared withthe control group,the level of endothelin-1 expression in the impotence model group,medication group of impotence model

  7. An analytical model of the knee for estimation of internal forces during exercise. (United States)

    Zheng, N; Fleisig, G S; Escamilla, R F; Barrentine, S W


    An analytical model of the knee joint was developed to estimate the forces at the knee during exercise. Muscle forces were estimated based upon electromyographic activities during exercise and during maximum voluntary isometric contraction (MVIC), physiological cross-sectional area (PCSA), muscle fiber length at contraction and the maximum force produced by an unit PCSA under MVIC. Tibiofemoral compressive force and cruciate ligaments' tension were determined by using resultant force and torque at the knee, muscle forces, and orientations and moment arms of the muscles and ligaments. An optimization program was used to minimize the errors caused by the estimation of the muscle forces. The model was used in a ten-subject study of open kinetic chain exercise (seated knee extension) and closed kinetic chain exercises (leg press and squat). Results calculated with this model were compared to those from a previous study which did not consider muscle length and optimization. Peak tibiofemoral compressive forces were 3134 +/- 1040 N during squat, 3155 +/- 755 N during leg press and 3285 +/- 1927 N during knee extension. Peak posterior cruciate ligament tensions were 1868 +/- 878 N during squat, 1866 +/- 383 N during leg press and 959 +/- 300 N for seated knee extension. No significant anterior cruciate ligament (ACL) tension was found during leg press and squat. Peak ACL tension was 142 +/- 257 N during seated knee extension. It is demonstrated that the current model provided better estimation of knee forces during exercises, by preventing significant overestimates of tibiofemoral compressive forces and cruciate ligament tensions.

  8. Assessing Testlet Effect, Impact, Differential Testlet, and Item Functioning Using Cross-Classified Multilevel Measurement Modeling

    Directory of Open Access Journals (Sweden)

    Hamdollah Ravand


    Full Text Available The present study used the two-level testlet response model (MMMT-2 to assess impact, differential item functioning (DIF, and differential testlet functioning (DTLF in a reading comprehension test. The data came from 21,641 applicants into English Masters’ programs at Iranian state universities. Testlet effects were estimated, and items and testlets that were functioning differentially for test takers of different genders and majors were identified. Also parameter estimates obtained under MMMT-2 and those obtained under the two-level hierarchical generalized linear model (HGLM-2 were compared. The results indicated that ability estimates obtained under the two models were significantly different at the lower and upper ends of the ability distribution. In addition, it was found that ignoring local item dependence (LID would result in overestimation of the precision of the ability estimates. As for the difficulty of the items, the estimates obtained under the two models were almost the same, but standard errors were significantly different.

  9. Effects of Rate-Limited Mass Transfer on Modeling Vapor Intrusion with Aerobic Biodegradation. (United States)

    Chen, Yiming; Hou, Deyi; Lu, Chunhui; Spain, Jim C; Luo, Jian


    Most of the models for simulating vapor intrusion accept the local equilibrium assumption for multiphase concentration distributions, that is, concentrations in solid, liquid and vapor phases are in equilibrium. For simulating vapor transport with aerobic biodegradation controlled by counter-diffusion processes, the local equilibrium assumption combined with dual-Monod kinetics and biomass decay may yield near-instantaneous behavior at steady state. The present research investigates how predicted concentration profiles and fluxes change as interphase mass transfer resistances are increased for vapor intrusion with aerobic biodegradation. Our modeling results indicate that the attenuation coefficients for cases with and without mass transfer limitations can be significantly different by orders of magnitude. Rate-limited mass transfer may lead to larger overlaps of contaminant vapor and oxygen concentrations, which cannot be simulated by instantaneous reaction models with local equilibrium mass transfer. In addition, the contaminant flux with rate-limited mass transfer is much smaller than that with local equilibrium mass transfer, indicating that local equilibrium mass transfer assumption may significantly overestimate the biodegradation rate and capacity for mitigating vapor intrusion through the unsaturated zone. Our results indicate a strong research need for field tests to examine the validity of local equilibrium mass transfer, a widely accepted assumption in modeling vapor intrusion.

  10. Thermospheric density model biases at the 23rd sunspot maximum (United States)

    Pardini, C.; Moe, K.; Anselmo, L.


    statistically significant. The minimum average biases were obtained with JB2008, NRLMSISE-00 and GOST-2004. Above 500 km, where only one satellite was analyzed (at 630 km), and errors tend to increase with altitude, it cannot be asserted that the calculated biases are significant. Nevertheless, they are presented to show how the various models diverge at higher altitudes. Around 630 km, NRLMSISE-00 had a negligible average bias, while the other models underestimated (GOST-2004) or overestimated the average density, by amounts varying between 6% and 16%. However, in terms of semi-major axis root mean square residuals, JB2006 and JB2008 were the best in any case. Below 500 km, the short-term behavior of the models was also investigated by fitting the semi-major axis decay over 30-day arcs. The resulting fitted drag coefficients displayed a significant variability, probably associated with mismodeled density variations, but JB2008, followed by JB2006, provided the smallest semi-major axis residuals and a reduced short-term variability of the density bias at just a few frequencies, having been probably successful in removing a significant fraction of the mismodeling sources.

  11. What's Worth Teaching? Extracting Significant Content. (United States)

    Switzer, Thomas J.


    A model which secondary social studies teachers could apply to their content area suggests an interplay between the inductive and the deductive--where students first identify a proposition from an examination of evidence and then test the proposition to assess its power in helping students understand the complex nature of social reality.…

  12. Significance of primary irradiation creep in graphite

    CSIR Research Space (South Africa)

    Erasmus, C


    Full Text Available Traditionally primary irradiation creep is introduced into graphite analysis by applying the appropriate amount of creep strain to the model at the initial time-step. This is valid for graphite components that are subjected to high fast neutron flux...

  13. Significance of oxygen transport through aquaporins (United States)

    Zwiazek, Janusz J.; Xu, Hao; Tan, Xiangfeng; Navarro-Ródenas, Alfonso; Morte, Asunción


    Aquaporins are membrane integral proteins responsible for the transmembrane transport of water and other small neutral molecules. Despite their well-acknowledged importance in water transport, their significance in gas transport processes remains unclear. Growing evidence points to the involvement of plant aquaporins in CO2 delivery for photosynthesis. The role of these channel proteins in the transport of O2 and other gases may also be more important than previously envisioned. In this study, we examined O2 permeability of various human, plant, and fungal aquaporins by co-expressing heterologous aquaporin and myoglobin in yeast. Two of the most promising O2-transporters (Homo sapiens AQP1 and Nicotiana tabacum PIP1;3) were confirmed to facilitate O2 transport in the spectrophotometric assay using yeast protoplasts. The over-expression of NtPIP1;3 in yeasts significantly increased their O2 uptake rates in suspension culture. In N. tabacum roots subjected to hypoxic hydroponic conditions, the transcript levels of the O2-transporting aquaporin NtPIP1;3 significantly increased after the seven-day hypoxia treatment, which was accompanied by the increase of ATP levels in the apical root segments. Our results suggest that the functional significance of aquaporin-mediated O2 transport and the possibility of controlling the rate of transmembrane O2 transport should be further explored. PMID:28079178

  14. Mycotoxins: significance to global economics and health (United States)

    Mycotoxins are fungal metabolites produced my micro-fungi (molds and mildews) that have significant impacts on global economics and health. Some of these metabolites are beneficial, but most are harmful and have been associated with well-known epidemics dating back to medieval times. The terms ‘myco...

  15. The Philosophical Significance of Universal Grammar (United States)

    Hinzen, Wolfram


    Throughout its long history, the project of a science of grammar has always been an inherently philosophical one, in which the study of grammar was taken to have special epistemological significance. I ask why 20th and 21st century inquiry into Universal Grammar (UG) has largely lost this dimension, a fact that I argue is partially responsible for…

  16. Significance tests and sample homogeneity loophole

    CERN Document Server

    Kupczynski, Marian


    In their recent comment, published in Nature, Jeffrey T.Leek and Roger D.Peng discuss how P-values are widely abused in null hypothesis significance testing . We agree completely with them and in this short comment we discuss the importance of sample homogeneity tests. No matter with how much scrutiny data are gathered if homogeneity tests are not performed the significance tests suffer from sample homogeneity loophole and the results may not be trusted. For example sample homogeneity loophole was not closed in the experiment testing local realism in which a significant violation of Eberhard inequality was found. We are not surprised that Bell type inequalities are violated since if the contextual character of quantum observables is properly taken into account these inequalities cannot be proven. However in order to trust the significance of the violation sample homogeneity loophole must be closed. Therefore we repeat after Jeffrey T.Leek and Roger D.Peng that sample homogeneity loophole is probably just the ...

  17. Significant Workplace Change: Perspectives of Survivors (United States)

    Kohut, Ann Marie


    The ever-increasing pace of workplace change is well documented in the literature, yet little is known about how an individual adapts to significant change in the workplace. Continuous learning is key to successful adaptation; however, are employees' adaptation to change influenced by their approaches to learning? The purpose of this study was to…

  18. Scope and Significance of Eating Disorders. (United States)

    Mitchell, James E.; Eckert, Elke D.


    Describes the increasing prevalence of anorexia nervosa and bulimia in many industrialized societies, and their association with significant morbidity and mortality. Discusses the genetic risks for the development of anorexia nervosa, and treatment strategies. Of these, pharmacotherapy and psychotherapy, particularly those incorporating…

  19. Can Educationally Significant Learning Be Assessed? (United States)

    Stolz, Steven A.


    This article argues that assessment is a central feature of teaching, particularly as a means to determine whether what has been taught has been learnt. However, I take issue with the current trend in education which places a significant amount of emphasis upon large-scale public testing, which in turn has exacerbated the…

  20. Bullying in Academe: Prevalent, Significant, and Incessant (United States)

    Cassell, Macgorine A.


    This paper examines the top-down perspective of bullying and mobbing of professors by analyzing why it is prevalent, significant, and incessant and then proposes a framework to produce a caring, respectful, and safe environment for professors to engage in their teaching, scholarship, and service. The author suggests that the failure of…

  1. Encounter Probability of Significant Wave Height

    DEFF Research Database (Denmark)

    Liu, Z.; Burcharth, H. F.

    The determination of the design wave height (often given as the significant wave height) is usually based on statistical analysis of long-term extreme wave height measurement or hindcast. The result of such extreme wave height analysis is often given as the design wave height corresponding to a c...

  2. Surface characterization based upon significant topographic features

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, J; Grime, D; Blateyron, F, E-mail: [Digital Surf, 16 rue Lavoisier, F-25000 Besancon (France)


    Watershed segmentation and Wolf pruning, as defined in ISO 25178-2, allow the detection of significant features on surfaces and their characterization in terms of dimension, area, volume, curvature, shape or morphology. These new tools provide a robust way to specify functional surfaces.

  3. Discovering the Significance of Scientific Design Practice

    DEFF Research Database (Denmark)

    Pries-Heje, Jan; Ba